Method of manufacturing semiconductor device
10573531 ยท 2020-02-25
Assignee
Inventors
Cpc classification
G03F1/42
PHYSICS
G03F9/7084
PHYSICS
H01L21/3086
ELECTRICITY
G03F9/7003
PHYSICS
G03F7/2022
PHYSICS
H01L21/0337
ELECTRICITY
G03F7/70425
PHYSICS
H01L23/544
ELECTRICITY
H01L21/0273
ELECTRICITY
G03F7/70633
PHYSICS
International classification
H01L21/00
ELECTRICITY
G03F1/42
PHYSICS
G03F9/00
PHYSICS
H01L21/311
ELECTRICITY
H01L21/3213
ELECTRICITY
H01L21/027
ELECTRICITY
Abstract
A method of manufacturing a semiconductor device includes forming a first photoresist film over a substrate, exposing a first pattern including an alignment pattern in a first region, forming, on the substrate, an alignment mark corresponding to the exposed alignment pattern, forming a second photoresist film over the substrate on which the alignment mark is formed, dividing a second pattern into a plurality of regions and exposing the divided regions separately in a second region while performing positioning with respect to the alignment mark, and developing the second photoresist film and forming the second photoresist film having the second pattern, wherein at least a part of the second region is located outside an effective exposure region of an exposure apparatus in exposure of the first pattern.
Claims
1. A method of manufacturing a semiconductor device comprising: forming a first photoresist film over a substrate; exposing a first pattern including an alignment pattern on the first photoresist film in a first region on the substrate; forming, on the substrate, an alignment mark corresponding to the alignment pattern of the first pattern exposed on the first photoresist film; forming a second photoresist film over the substrate on which the alignment mark is formed; exposing a second pattern divided into a plurality of pattern regions on the second photoresist film in a second region on the substrate, the plurality of pattern regions being separately exposed while performing positioning with respect to the alignment mark; and developing the second photoresist film and forming the second photoresist film having the second pattern, wherein at least a part of the second region is located outside an effective exposure region of an exposure apparatus in exposure of the first pattern.
2. The method of manufacturing a semiconductor device according to claim 1, wherein each of the plurality of pattern regions of the second pattern at least partially overlaps with the first region.
3. The method of manufacturing a semiconductor device according to claim 1, wherein the first region is arranged inside a circumference of the second region.
4. The method of manufacturing a semiconductor device according to claim 2, wherein the first region is arranged inside a circumference of the second region.
5. The method of manufacturing a semiconductor device according to claim 3, wherein a plurality of the first regions are arranged inside the circumference of the second region.
6. The method of manufacturing a semiconductor device according to claim 4, wherein a plurality of the first regions are arranged inside the circumference of the second region.
7. The method of manufacturing a semiconductor device according to claim 1, wherein the second region is larger than an effective exposure region of an exposure apparatus that exposes the second pattern, and wherein each of the plurality of pattern regions is smaller than the effective exposure region of the exposure apparatus that exposes the second pattern.
8. The method of manufacturing a semiconductor device according to claim 1, wherein the second region is a chip region of a semiconductor device.
9. The method of manufacturing a semiconductor device according to claim 1, wherein at least one alignment mark is arranged in each region corresponding to each of the plurality of pattern regions of the second pattern of the substrate.
10. The method of manufacturing a semiconductor device according to claim 1, wherein the first pattern further includes an alignment accuracy measuring pattern.
11. The method of manufacturing a semiconductor device according to claim 1, wherein the plurality of pattern regions are arranged two-dimensionally in the second region.
12. The method of manufacturing a semiconductor device according to claim 1, wherein each of the plurality of pattern regions has an overlapping region between neighboring regions, and wherein the alignment mark is arranged in a region other than the overlapping region.
13. The method of manufacturing a semiconductor device according to claim 1, wherein the forming the alignment mark includes developing the exposed first photoresist film and forming the alignment mark formed from the first photoresist film.
14. The method of manufacturing a semiconductor device according to claim 13, wherein the forming the alignment mark further includes etching the substrate using the first photoresist film as a mask and transcribing the alignment mark onto the substrate.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
(5)
(6)
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(8)
DESCRIPTION OF THE EMBODIMENTS
(9) Preferred embodiments of the present invention will now be described in detail in accordance with the accompanying drawings.
First Embodiment
(10) A semiconductor device and a method of manufacturing the same according to a first embodiment of the present invention will be described with reference to
(11)
(12) The formation of patterns on the semiconductor substrate is performed by using photolithography. After a photoresist film is formed over the semiconductor substrate, a predetermined pattern is exposed on this photoresist film by using an exposure apparatus, the exposed photoresist film is developed, and thereby the exposed pattern is transcribed on the photoresist film. For example, the patterned photoresist film can be used as a mask in etching of the semiconductor substrate or a film provided thereon or a mask for ion implantation. The patterned photoresist film can be used as an alignment mark in a subsequent photolithography step.
(13) The exposure apparatus used in exposure of a pattern on a photoresist film on the semiconductor substrate has an effective exposure region that is specific for the apparatus. The effective exposure region is the maximum exposure region that can be exposed by one shot and is determined by performance of a projection optical system of the exposure apparatus. In the present embodiment, an exposure apparatus having a size of the effective exposure region of 26 mm by 33 mm at the maximum is assumed. That is, the size of the chip region 10 of the semiconductor device described above is larger than the size of the effective exposure region of this exposure apparatus. Thus, in order to use this exposure apparatus to expose a pattern on the chip region 10 of the semiconductor device according to the present embodiment, it is necessary to divide the chip region 10 into a plurality of regions each smaller than the effective exposure region of the exposure apparatus and separately expose the patterns corresponding to respective divided regions.
(14) When the length in the X-direction of the effective exposure region is 26 mm and the Y-direction thereof is 33 mm, the chip region 10 of the semiconductor device according to the present embodiment has a larger size than the effective exposure region in the X-direction and the same length as the effective exposure region in the Y-direction. Therefore, as illustrated in
(15) Note that the divided pattern regions 12 are not necessarily required to have the same size. Further, the chip region 10 may be divided into three or more divided pattern regions 12. Further, an overlapping region is provided between the neighboring divided pattern regions 12 taking positioning shift into consideration, though not depicted or described here for simplicity.
(16) In the method of manufacturing the semiconductor device according to the present embodiment, prior to exposure of patterns on the divided pattern regions 12A and 12B, an alignment mark used for positioning in the exposure of these patterns is formed on the semiconductor substrate. The formation of the alignment mark is performed through lithography using a reticle which is different from the reticle used for exposing the divided pattern regions 12A and 12B.
(17)
(18)
(19) At least a part of the chip region 10 is located outside the effective exposure region of the exposure apparatus in exposure of patterns including the alignment patterns 22X and 22Y For example, the alignment mark arrangement region 14 is smaller than the size of the chip region 10 and arranged inside the circumference of the chip region 10 as illustrated in
(20) It is desirable for each of the divided pattern regions 12A and 12B to have a region overlapping with the alignment mark arrangement region 14. Such a configuration allows for a shorter distance from each of the alignment marks 16X and 16Y arranged inside the alignment mark arrangement region 14 to each of the divided pattern regions 12A and 12B, and this can improve the positioning accuracy.
(21) Next, the method of manufacturing the semiconductor device according to the present embodiment will be more specifically described by using
(22) First, the reticle 20 provided with the alignment patterns 22X and 22Y, a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12A, and a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12B are prepared.
(23) Next, a photoresist material is spin-coated over a semiconductor substrate to be processed, prebake is performed thereon, and thereby a semiconductor substrate 30 provided with a photoresist film over the surface is prepared.
(24) Next, the reticle 20 in which the alignment patterns 22X and 22Y are provided is set in the exposure apparatus. The exposure apparatus mounts the reticle 20 on a reticle stage and performs positioning of the reticle 20 with the reticle stage.
(25) Next, the semiconductor substrate 30 on which the photoresist film is provided is set in the exposure apparatus. The exposure apparatus mounts the semiconductor substrate 30 on a wafer stage.
(26) Next, the exposure apparatus controls the wafer stage to expose the pattern provided in the reticle 20 on the semiconductor substrate 30 while moving the semiconductor substrate 30 in the X-direction and the Y-direction at a pitch corresponding to the length in the X-direction and the length in the Y-direction of the chip region 10.
(27) For example, each of the regions partitioned by a one-dot-chain line in
(28) In such a way, the patterns provided in the reticle 20 are exposed within each of the chip regions 10 of the semiconductor substrate 30 defined by the arrangement reference information, respectively. Each of the regions partitioned by a dotted line in
(29) Next, the semiconductor substrate 30 on which the patterns provided in the reticle 20 have been exposed is extracted from the exposure apparatus, and the exposed photoresist film is developed by using a developing fluid. Thereby, a photoresist film having the alignment marks 16X and 16Y corresponding to the alignment patterns 22X and 22Y on the reticle 20 is formed within each of the chip regions 10 of the semiconductor substrate 30.
(30) Next, the semiconductor substrate 30 is etched using the photoresist film as a mask in which the alignment marks 16X and 16Y are formed, and the alignment marks 16X and 16Y are transcribed on the semiconductor substrate 30. The photoresist film over the semiconductor substrate 30 is then removed by ashing or the like.
(31) In such a way, the alignment marks 16X and 16Y formed of a difference in level on the surface of the semiconductor substrate 30 are formed within each of the chip regions 10 of the semiconductor substrate 30 (
(32) Next, a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12A and a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12B are set in the exposure apparatus.
(33) Next, a photoresist film is again formed over the semiconductor substrate 30 on which the alignment marks 16X and 16Y are formed, which is set in the exposure apparatus. The exposure apparatus mounts the semiconductor substrate 30 on the wafer stage.
(34) Next, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12A on the reticle stage and performs positioning with respect to the reticle stage.
(35) Next, the exposure apparatus measures the alignment marks 16X and 16Y for several shots formed on the semiconductor substrate 30 and examines alignment information indicating coordinate positions of the alignment marks 16X and 16Y on the semiconductor substrate 30. The components of a shift in the X-direction and Y-direction, a rotational shift, a magnification error, or the like of the alignment mark arrangement region 14 are then calculated from the examined alignment information. Furthermore, the original arrangement reference information is corrected taking these components into consideration.
(36) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12A. Thereby, a latent image of the pattern exposed on the divided pattern region 12A is formed on the photoresist film of the semiconductor substrate 30 (
(37) Next, after extracting the reticle on the reticle stage, the exposure apparatus mounts the reticle provided with a predetermined pattern to be exposed on the divided pattern region 12B on the reticle stage and performs positioning with respect to the reticle stage.
(38) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12B. Thereby, a latent image of the pattern exposed on the divided pattern region 12B is formed on the photoresist film of the semiconductor substrate 30 (
(39) Next, the semiconductor substrate 30 on which the exposure of the patterns on the divided pattern regions 12A and 12B is completed is extracted from the exposure apparatus, and the exposed photoresist film is developed by using a developing fluid. Thereby, a photoresist film having a predetermined pattern is formed within each of the chip regions 10 of the semiconductor substrate 30.
(40) Next, the patterned photoresist film is used to perform a predetermined process on the semiconductor substrate 30. For example, the semiconductor substrate 30 or the film provided thereon is etched using the photoresist film as a mask, and the pattern of the photoresist film is transcribed on the semiconductor substrate 30 or the film provided thereon. Alternatively, ion implantation is performed using the photoresist film as a mask to add an impurity to a predetermined region of the semiconductor substrate 30. Then, the photoresist film on the semiconductor substrate 30 is removed by ashing or the like.
(41) As discussed above, in the method of manufacturing the semiconductor device according to the present embodiment, the same alignment mark is used to perform exposure on the plurality of divided pattern regions 12A and 12B forming the chip region 10. Therefore, according to the present embodiment, the accuracy in connecting together the pattern formed in the divided pattern region 12A and the pattern formed in the divided pattern region 12B can be improved.
Second Embodiment
(42) A method of manufacturing a semiconductor device according to a second embodiment of the present invention will be described with reference to
(43)
(44) The chip region 10 of the semiconductor device according to the present embodiment is larger than the size of the effective exposure region in both the sizes in the X-direction and the Y-direction. Therefore, as illustrated in
(45) Also in the method of manufacturing the semiconductor device according to the present embodiment, prior to exposure of patterns on the divided pattern regions 12A, 12B, 12C, and 12D, an alignment mark used for positioning in the exposure of these patterns is formed on the semiconductor substrate. The formation of the alignment mark is performed through lithography using a reticle which is different from the reticle used for exposing the divided pattern regions 12A, 12B, 12C, and 12D.
(46)
(47)
(48) At least a part of the chip region 10 is located outside the effective exposure region of the exposure apparatus in exposure of patterns including the alignment patterns 22X and 22Y For example, the alignment mark arrangement region 14 is smaller than the size of the chip region 10 and arranged inside the circumference of the chip region 10 as illustrated in
(49) It is desirable for each of the divided pattern regions 12A, 12B, 12C, and 12D to have regions overlapping with the alignment mark arrangement region 14. Such a configuration allows for a shorter distance from each of the alignment marks 16X and 16Y arranged inside the alignment mark arrangement region 14 to each of the divided pattern regions 12A, 12B, 12C, and 12D, and this can improve the positioning accuracy.
(50) Note that, as a divided exposure method using the layout illustrated in
(51) The first method is a method of using an alignment mark formed in the neighboring divided pattern regions to perform positioning. For example, first, a predetermined pattern including an alignment mark is formed in the divided pattern region 12B. Next, the alignment mark formed in the divided pattern region 12B is used to form predetermined patterns including the alignment marks in the divided pattern regions 12A and 12C, respectively. Next, the alignment mark formed in the divided pattern region 12A or the divided pattern region 12C is used to form a predetermined pattern in the divided pattern region 12D.
(52) The second method is a method of using alignment mark formed in one divided pattern region to perform positioning of remaining divided pattern regions. For example, first, a predetermined pattern including an alignment mark is formed in the divided pattern region 12B. Next, the alignment mark formed in the divided pattern region 12B is used to form predetermined patterns in the divided pattern regions 12A, 12C, and 12D, respectively.
(53) In the first method, however, positioning of the divided pattern region 12D to the divided pattern region 12B is indirect positioning via the use of the pattern of the divided pattern region 12A or the divided pattern region 12C, and thus the accuracy in connecting-together may be decrease. Further, in the second method, since the distance from the divided pattern region 12B to the divided pattern region 12D is large and the positioning accuracy significantly depends on the stepping accuracy of the exposure apparatus, the accuracy in connecting-together may decrease.
(54) In this regard, according to the method of manufacturing the semiconductor device according to the present embodiment, since the same alignment mark is used to perform positioning of a plurality of divided pattern regions, this can improve the accuracy in connecting together the divided pattern regions. Further, since a common alignment mark can be arranged near a plurality of divided pattern regions, the influence of the stepping accuracy of the exposure apparatus can be reduced, and the accuracy in connecting the divided pattern regions together can be improved.
(55) Next, the method of manufacturing the semiconductor device according to the present embodiment will be more specifically described by using
(56) First, the reticle 20 in which the alignment patterns 22X and 22Y are provided is prepared. Further, reticles provided with predetermined patterns to be exposed on the divided pattern regions 12A, 12B, 12C, and 12D are prepared, respectively.
(57) Next, a photoresist material is spin-coated over a semiconductor substrate to be processed, prebake is performed thereon, and thereby a semiconductor substrate 30 provided with a photoresist film over the surface is prepared.
(58) Next, the reticle 20 in which the alignment patterns 22X and 22Y are provided is set in the exposure apparatus. The exposure apparatus mounts the reticle 20 on a reticle stage and performs positioning of the reticle 20 with the reticle stage.
(59) Next, the semiconductor substrate 30 on which the photoresist film is provided is set in the exposure apparatus. The exposure apparatus mounts the semiconductor substrate 30 on a wafer stage.
(60) Next, the exposure apparatus controls the wafer stage to expose the pattern provided in the reticle 20 on the semiconductor substrate 30 while moving the semiconductor substrate 30 in the X-direction and the Y-direction at a pitch corresponding to the length in the X-direction and the length in the Y-direction of the chip region 10.
(61) For example, each of the regions partitioned by a one-dot-chain line in
(62) In such a way, the patterns provided in the reticle 20 are exposed within each of the chip regions 10 of the semiconductor substrate 30 defined by the arrangement reference information, respectively. Each of the regions partitioned by a dotted line in
(63) Next, the semiconductor substrate 30 on which the patterns provided in the reticle 20 have been exposed is extracted from the exposure apparatus, and the exposed photoresist film is developed by using a developing fluid. Thereby, the alignment marks 16X and 16Y corresponding to the alignment patterns 22X and 22Y on the reticle 20 are formed within each of the chip regions 10 of the semiconductor substrate 30.
(64) Next, the semiconductor substrate 30 is etched using the photoresist film as a mask in which the alignment marks 16X and 16Y are formed, and the alignment marks 16X and 16Y are transcribed on the semiconductor substrate 30. The photoresist film on the semiconductor substrate 30 is then removed by ashing or the like.
(65) In such a way, the alignment marks 16X and 16Y formed of a difference in level on the surface of the semiconductor substrate 30 are formed within each of the chip regions 10 of the semiconductor substrate 30 (
(66) Next, four reticles each provided with a predetermined pattern to be exposed on the divided pattern regions 12A, 12B, 12C, and 12D are set in the exposure apparatus.
(67) Next, a photoresist film is again formed over the semiconductor substrate 30 on which the alignment marks 16X and 16Y are formed, which is set in the exposure apparatus. The exposure apparatus mounts the semiconductor substrate 30 on the wafer stage.
(68) Next, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12A on the reticle stage and performs positioning with respect to the reticle stage.
(69) Next, the exposure apparatus measures the alignment marks 16X and 16Y for several shots formed on the semiconductor substrate 30 and examines alignment information indicating coordinate positions of the alignment marks 16X and 16Y on the semiconductor substrate 30. The components of a shift in the X-direction and Y-direction, a rotational shift, a magnification error, or the like of the alignment mark arrangement region 14 are then calculated from the examined alignment information. Furthermore, the original arrangement reference information is corrected taking these components into consideration.
(70) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12A. Thereby, a latent image of the pattern exposed on the divided pattern region 12A is formed on the photoresist film of the semiconductor substrate 30 (
(71) Next, after extracting the reticle on the reticle stage, the exposure apparatus mounts the reticle provided with a predetermined pattern to be exposed on the divided pattern region 12B on the reticle stage and performs positioning with respect to the reticle stage.
(72) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12B. Thereby, a latent image of the pattern exposed on the divided pattern region 12B is formed on the photoresist film of the semiconductor substrate 30 (
(73) Next, after extracting the reticle on the reticle stage, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12C on the reticle stage and performs positioning with respect to the reticle stage.
(74) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12C. Thereby, a latent image of the pattern exposed on the divided pattern region 12C is formed on the photoresist film of the semiconductor substrate 30 (
(75) Next, after extracting the reticle on the reticle stage, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12D on the reticle stage and performs positioning with respect to the reticle stage.
(76) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12D. Thereby, a latent image of the pattern exposed on the divided pattern region 12D is formed on the photoresist film of the semiconductor substrate 30 (
(77) Next, the semiconductor substrate 30 on which the exposure of the patterns on the divided pattern regions 12A, 12B, 12C, and 12D is completed is extracted from the exposure apparatus, and the exposed photoresist film is developed by using a developing fluid. Thereby, a photoresist film having a predetermined pattern is formed within each of the chip regions 10 of the semiconductor substrate 30.
(78) Next, the patterned photoresist film is used to perform a predetermined process on the semiconductor substrate 30. For example, the semiconductor substrate 30 or the film provided thereon is etched using the photoresist film as a mask, the pattern of the photoresist film is transcribed on the semiconductor substrate 30 or the film provided thereon. Alternatively, ion implantation is performed using the photoresist film as a mask to add an impurity to a predetermined region of the semiconductor substrate 30. Then, the photoresist film on the semiconductor substrate 30 is removed by ashing or the like.
(79) As discussed above, in the method of manufacturing the semiconductor device according to the present embodiment, the same alignment mark is used to perform exposure on the plurality of divided pattern regions 12A to 12D forming the chip region 10. Therefore, according to the present embodiment, the accuracy in connecting together the divided pattern region 12A to 12D can be improved.
Third Embodiment
(80) A method of manufacturing a semiconductor device according to a third embodiment of the present invention will be described with reference to
(81)
(82) The chip region 10 of the semiconductor device according to the present embodiment is larger than the size of the effective exposure region in both the sizes in the X-direction and the Y-direction. Therefore, as illustrated in
(83) Also in the method of manufacturing the semiconductor device according to the present embodiment, prior to exposure of patterns on the divided pattern regions 12A, 12B, 12C, and 12D, an alignment mark used for positioning in the exposure of these patterns is formed on the semiconductor substrate. The formation of the alignment mark is performed through lithography using a reticle which is different from the reticle used for exposing the divided pattern regions 12A, 12B, 12C, and 12D.
(84)
(85)
(86) At least a part of the chip region 10 is located outside the effective exposure region of the exposure apparatus in exposure of patterns including the alignment patterns 22X and 22Y and the alignment accuracy measuring patterns 24. For example, the alignment mark arrangement region 14 is smaller than the size of the chip region 10 and arranged inside the circumference of the chip region 10 as illustrated in
(87) Within the alignment mark arrangement region 14, the alignment marks 16X and 16Y based on the alignment patterns 22X and 22Y on the reticle 20 are arranged. In the example of
(88) Further, within the alignment mark arrangement region 14, alignment accuracy measuring marks 18 based on the alignment accuracy measuring patterns 24 are arranged on the reticle 20. In the example of
(89) With such a configuration, the accuracy in connecting together the divided pattern regions can be improved in the same manner as the case of the second embodiment. Further, the alignment accuracy of each divided pattern region can be improved.
(90) Next, the method of manufacturing the semiconductor device according to the present embodiment will be more specifically described by using
(91) First, the reticle 20 in which the alignment patterns 22X and 22Y and the alignment accuracy measuring patterns 24 are provided is prepared. Further, reticles provided with predetermined patterns to be exposed on the divided pattern regions 12A, 12B, 12C, and 12D are prepared, respectively.
(92) Next, a photoresist material is spin-coated over a semiconductor substrate to be processed, prebake is performed thereon, and thereby a semiconductor substrate 30 provided with a photoresist film over the surface is prepared.
(93) Next, the reticle 20 in which the alignment patterns 22X and 22Y and the alignment accuracy measuring patterns 24 are provided is set in the exposure apparatus. The exposure apparatus mounts the reticle 20 on a reticle stage and performs positioning of the reticle 20 with the reticle stage.
(94) Next, the semiconductor substrate 30 on which the photoresist film is provided is set in the exposure apparatus. The exposure apparatus mounts the semiconductor substrate 30 on a wafer stage.
(95) Next, the exposure apparatus controls the wafer stage to expose the pattern provided in the reticle 20 on the semiconductor substrate 30 while moving the semiconductor substrate 30 in the X-direction and the Y-direction at a pitch corresponding to the length in the X-direction and the length in the Y-direction of the chip region 10.
(96) For example, each of the regions partitioned by a one-dot-chain line in
(97) In such a way, the patterns provided in the reticle 20 are exposed within each of the chip regions 10 of the semiconductor substrate 30 defined by the arrangement reference information, respectively. Each of the regions partitioned by a dotted line in
(98) Next, the semiconductor substrate 30 on which the patterns provided in the reticle 20 have been exposed is extracted from the exposure apparatus, and the exposed photoresist film is developed by using a developing fluid. Thereby, the alignment marks 16X and 16Y corresponding to the alignment patterns 22X and 22Y on the reticle 20 are formed within each of the chip regions 10 of the semiconductor substrate 30. Further, within each of the chip regions 10 of the semiconductor substrate 30, the alignment accuracy measuring marks 18 corresponding to the alignment accuracy measuring marks 24 on the reticle 20 are formed.
(99) Next, the semiconductor substrate 30 is etched using the photoresist film as a mask in which the alignment marks 16X and 16Y and the alignment accuracy measuring marks 18 are formed. Thereby, the alignment marks 16X and 16Y and the alignment accuracy measuring marks 18 are transcribed on the semiconductor substrate 30. The photoresist film over the semiconductor substrate 30 is then removed by ashing or the like.
(100) In such a way, the alignment marks 16X and 16Y and the alignment accuracy measuring marks 18 formed of a difference in level on the surface of the semiconductor substrate 30 are formed within each of the chip regions 10 of the semiconductor substrate 30 (
(101) Next, four reticles each provided with a predetermined pattern to be exposed on the divided pattern regions 12A, 12B, 12C, and 12D are set in the exposure apparatus, respectively.
(102) Next, a photoresist film is again formed over the semiconductor substrate 30 on which the alignment marks 16X and 16Y and the alignment accuracy measuring marks 18 are formed, which is set in the exposure apparatus. The exposure apparatus mounts the semiconductor substrate 30 on the wafer stage.
(103) Next, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12A on the reticle stage and performs positioning with respect to the reticle stage.
(104) Next, the exposure apparatus measures the alignment marks 16X and 16Y for several shots formed on the semiconductor substrate 30 and examines alignment information indicating coordinate positions of the alignment marks 16X and 16Y on the semiconductor substrate 30. The components of a shift in the X-direction and Y-direction, a rotational shift, a magnification error, or the like of the alignment mark arrangement region 14 are then calculated from the examined alignment information. Furthermore, the original arrangement reference information is corrected taking these components into consideration.
(105) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12A. Thereby, a latent image of the pattern exposed on the divided pattern region 12A is formed on the photoresist film of the semiconductor substrate 30 (
(106) Next, after extracting the reticle on the reticle stage, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12B on the reticle stage and performs positioning with respect to the reticle stage.
(107) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12B. Thereby, a latent image of the pattern exposed on the divided pattern region 12B is formed on the photoresist film of the semiconductor substrate 30 (
(108) Next, after extracting the reticle on the reticle stage, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12C on the reticle stage and performs positioning with respect to the reticle stage.
(109) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12C. Thereby, a latent image of the pattern exposed on the divided pattern region 12C is formed on the photoresist film of the semiconductor substrate 30 (
(110) Next, after extracting the reticle on the reticle stage, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12D on the reticle stage and performs positioning with respect to the reticle stage.
(111) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12D. Thereby, a latent image of the pattern exposed on the divided pattern region 12D is formed on the photoresist film of the semiconductor substrate 30 (
(112) Next, the semiconductor substrate 30 on which the exposure of the patterns on the divided pattern regions 12A, 12B, 12C, and 12D is completed is extracted from the exposure apparatus, and the exposed photoresist film is developed by using a developing fluid. Thereby, a photoresist film having a predetermined pattern is formed within each of the chip regions 10 of the semiconductor substrate 30.
(113) Next, the alignment accuracy of the pattern of the photoresist film formed in the divided pattern regions 12A, 12B, 12C, and 12D is measured by using an alignment accuracy measuring instrument. In measurement of alignment accuracy, the arrangement of the resist pattern to the alignment accuracy measuring marks 18 arranged in the divided pattern regions 12A, 12B, 12C, and 12D, respectively, is measured. Measurement parameters include a shift component in the X-direction, a shift component in the Y-direction, a rotational component, and/or a magnification component.
(114) When these measured parameters are within a desired range, it is determined that the positioning accuracy is good, and the process proceeds to the next step. When the measured parameters are out of a desired range, it is determined that the positioning accuracy is not good, an ashing process, a stripping solution, or the like is used to remove the photoresist film, and then formation of the photoresist film and exposure onto the divided pattern regions 12A, 12B, 12C, and 12D are again performed. At this time, the arrangement reference information may be corrected based on the parameters measured by the alignment accuracy measuring instrument if necessary.
(115) Next, the patterned photoresist film is used to perform a predetermined process on the semiconductor substrate 30. For example, the semiconductor substrate 30 or the film provided thereon is etched using the photoresist film as a mask, the pattern of the photoresist film is transcribed on the semiconductor substrate 30 or the film provided thereon. Alternatively, ion implantation is performed using the photoresist film as a mask to add an impurity to a predetermined region of the semiconductor substrate 30. Then, the photoresist film on the semiconductor substrate 30 is removed by ashing or the like.
(116) As discussed above, in the method of manufacturing the semiconductor device according to the present embodiment, the same alignment mark is used to perform exposure on the plurality of divided pattern regions 12A to 12D forming the chip region 10. Therefore, according to the present embodiment, the accuracy in connecting together the divided pattern region 12A to 12D can be improved.
Fourth Embodiment
(117) A method of manufacturing a semiconductor device according to a fourth embodiment of the present invention will be described with reference to
(118)
(119) Accordingly, in the present embodiment, as illustrated in
(120) As discussed above, by appropriately setting the number of the divided pattern regions 12 in accordance with the relationship between the size of the chip region 10 of the semiconductor device and the size of the effective exposure region of the exposure apparatus, a larger sized pattern of the semiconductor device can be exposed on the semiconductor substrate.
(121) Also in the method of manufacturing the semiconductor device according to the present embodiment, prior to exposure of patterns on the divided pattern regions 12A to 12F, an alignment mark used for positioning in the exposure of these patterns is formed on the semiconductor substrate. The formation of the alignment mark is performed through lithography using a reticle which is different from the reticle used for exposing the divided pattern regions 12A to 12F.
(122)
(123)
(124) As in the case of the semiconductor device according to the present embodiment, when the number of divided pattern regions 12 defined within the chip region 10 is relatively large, some divided pattern regions 12 may be arranged distant from the alignment mark arrangement region 14. An increase in the distance between the alignment marks 16X and 16Y and the divided pattern region 12 may cause a reduction in the positioning accuracy of the divided pattern region 12 of interest.
(125) Accordingly, in such a case, it is desirable to arrange a plurality of alignment mark arrangement regions 14 within a single chip region 10 to suppress occurrence of the divided pattern region 12 having a large distance from the alignment marks 16X and 16Y. In the example of
(126) Next, the method of manufacturing the semiconductor device according to the present embodiment will be more specifically described by using
(127) First, the reticle 20 in which the alignment patterns 22X and 22Y are provided is prepared. Further, reticles provided with predetermined patterns to be exposed on the divided pattern regions 12A to 12F are prepared, respectively.
(128) Next, a photoresist material is spin-coated over a semiconductor substrate to be processed, prebake is performed thereon, and thereby a semiconductor substrate 30 provided with a photoresist film over the surface is prepared.
(129) Next, the reticle 20 in which the alignment patterns 22X and 22Y are provided is set in the exposure apparatus. The exposure apparatus mounts the reticle 20 on a reticle stage and performs positioning of the reticle 20 with the reticle stage.
(130) Next, the semiconductor substrate 30 on which the photoresist film is provided is set in the exposure apparatus. The exposure apparatus mounts the semiconductor substrate 30 on a wafer stage.
(131) Next, the exposure apparatus controls the wafer stage to expose the pattern provided in the reticle 20 on the semiconductor substrate 30 while moving the semiconductor substrate 30 in the X-direction and the Y-direction at a pitch corresponding to the length in the X-direction and the length in the Y-direction of the chip region 10.
(132) For example, each of the regions partitioned by a one-dot-chain line in
(133) In such a way, the patterns provided in the reticle 20 are exposed within each of the chip regions 10 of the semiconductor substrate 30 defined by the arrangement reference information, respectively. Each of the regions partitioned by a dotted line in
(134) Next, in the same manner as the exposure on the alignment mark arrangement region 14A, patterns provided in the reticle 20 are exposed on regions different from the alignment mark arrangement region 14A within each of the chip regions 10, respectively. Each of the regions partitioned by a dotted line in
(135) Next, the semiconductor substrate 30 on which the patterns provided in the reticle 20 have been exposed is extracted from the exposure apparatus, and the exposed photoresist film is developed by using a developing fluid. Thereby, the alignment marks 16X and 16Y corresponding to the alignment patterns 22X and 22Y on the reticle 20 are formed within each of the chip regions 10 of the semiconductor substrate 30.
(136) Next, the semiconductor substrate 30 is etched using the photoresist film as a mask in which the alignment marks 16X and 16Y are formed, and the alignment marks 16X and 16Y are transcribed on the semiconductor substrate 30. The photoresist film over the semiconductor substrate 30 is then removed by ashing or the like.
(137) In such a way, the alignment marks 16X and 16Y formed of a difference in level on the surface of the semiconductor substrate 30 are formed within each of the chip regions 10 of the semiconductor substrate 30 (
(138) Next, six reticles each provided with a predetermined pattern to be exposed on the divided pattern regions 12A to 12F are set in the exposure apparatus.
(139) Next, a photoresist film is again formed over the semiconductor substrate 30 on which the alignment marks 16X and 16Y are formed, which is set in the exposure apparatus. The exposure apparatus mounts the semiconductor substrate 30 on the wafer stage.
(140) Next, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12A on the reticle stage and performs positioning with respect to the reticle stage.
(141) Next, the exposure apparatus measures the alignment marks 16X and 16Y for several shots formed on the semiconductor substrate 30 and examines alignment information indicating coordinate positions of the alignment marks 16X and 16Y on the semiconductor substrate 30. The components of a shift in the X-direction and the Y-direction, a rotational shift, a magnification error, or the like of the alignment mark arrangement regions 14A and 14B are then calculated from the examined alignment information. Furthermore, the original arrangement reference information is corrected taking these components into consideration.
(142) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12A. Thereby, a latent image of the pattern exposed on the divided pattern region 12A is formed on the photoresist film of the semiconductor substrate 30 (
(143) Next, after extracting the reticle on the reticle stage, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12B on the reticle stage and performs positioning with respect to the reticle stage.
(144) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12B. Thereby, a latent image of the pattern exposed on the divided pattern region 12B is formed on the photoresist film of the semiconductor substrate 30 (
(145) Next, after extracting the reticle on the reticle stage, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12C on the reticle stage and performs positioning with respect to the reticle stage.
(146) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12C. Thereby, a latent image of the pattern exposed on the divided pattern region 12C is formed on the photoresist film of the semiconductor substrate 30 (
(147) Next, after extracting the reticle on the reticle stage, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12D on the reticle stage and performs positioning with respect to the reticle stage.
(148) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12D. Thereby, a latent image of the pattern exposed on the divided pattern region 12D is formed on the photoresist film of the semiconductor substrate 30 (
(149) Next, after extracting the reticle on the reticle stage, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12E on the reticle stage and performs positioning with respect to the reticle stage.
(150) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12E. Thereby, a latent image of the pattern exposed on the divided pattern region 12E is formed on the photoresist film of the semiconductor substrate 30 (
(151) Next, after extracting the reticle on the reticle stage, the exposure apparatus mounts a reticle provided with a predetermined pattern to be exposed on the divided pattern region 12F on the reticle stage and performs positioning with respect to the reticle stage.
(152) Next, the exposure apparatus refers to the corrected arrangement reference information and moves the semiconductor substrate 30 mounted on the wafer stage in the X-direction and the Y-direction at a predetermined pitch by a step-and-repeat scheme. Then, for each motion, after the alignment marks 16X and 16Y of the corresponding chip region 10 are detected to perform positioning of the semiconductor substrate 30, the pattern on the reticle is projected in a reduced size onto the divided pattern region 12F. Thereby, a latent image of the pattern exposed on the divided pattern region 12F is formed on the photoresist film of the semiconductor substrate 30 (
(153) Next, the semiconductor substrate 30 on which the exposure of the patterns on the divided pattern regions 12A to 12F is completed is extracted from the exposure apparatus, and the exposed photoresist film is developed by using a developing fluid. Thereby, a photoresist film having a predetermined pattern is formed within each of the chip regions 10 of the semiconductor substrate 30.
(154) Next, the patterned photoresist film is used to perform a predetermined process on the semiconductor substrate 30. For example, the semiconductor substrate 30 or the film provided thereon is etched using the photoresist film as a mask, and the pattern of the photoresist film is transcribed on the semiconductor substrate 30 or the film provided thereon. Alternatively, ion implantation is performed using the photoresist film as a mask to add an impurity to a predetermined region of the semiconductor substrate 30. Then, the photoresist film on the semiconductor substrate 30 is removed by ashing or the like.
(155) As discussed above, in the method of manufacturing the semiconductor device according to the present embodiment, the same alignment mark is used to perform exposure on the plurality of divided pattern regions 12A to 12F forming the chip region 10. Therefore, according to the present embodiment, the accuracy in connecting together the divided pattern region 12A to 12F can be improved.
Modified Embodiments
(156) The present invention is not limited to the above-described embodiments, and various modifications are possible.
(157) For example, an example in which a part of the configuration of any of the embodiments is added to another embodiment or an example in which a part of the configuration of any of the embodiments is replaced with a part of the configuration of another embodiment is one of the embodiments of the present invention.
(158) Further, the number or arrangement of the divided pattern regions 12 arranged in the chip region 10 can be changed as appropriate in accordance with the size or the shape of the chip region 10.
(159) Further, while the case where the chip region of a semiconductor device is larger than the effective exposure region of an exposure apparatus is assumed in the embodiments described above, the present invention may be applied to a case where the chip region of a semiconductor device is smaller than the effective exposure region of an exposure apparatus.
(160) While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
(161) This application claims the benefit of Japanese Patent Application No. 2017-157583, filed Aug. 17, 2017, which is hereby incorporated by reference herein in its entirety.