Method for manufacturing semiconductor device, semiconductor manufacturing apparatus, and wafer lift pin-hole cleaning jig
09721910 ยท 2017-08-01
Assignee
Inventors
Cpc classification
C23C16/4405
CHEMISTRY; METALLURGY
H01L21/68742
ELECTRICITY
H01L2224/05025
ELECTRICITY
International classification
H01L21/687
ELECTRICITY
Abstract
To shorten a maintenance time of a semiconductor manufacturing apparatus and to improve productivity of a semiconductor manufacturing line. A semiconductor wafer is processed by the semiconductor manufacturing apparatus in which reaction product in the inside of a wafer lift pin hole was removed using a cleaning jig having a return on its tip part.
Claims
1. A method for manufacturing a semiconductor device, comprising the steps of: a) forming a thin film on a principal plane of a semiconductor wafer; b) applying a photoresist film onto the thin film; c) forming a mask pattern by transferring a predetermined circuit pattern to the photoresist film by photolithography; and d) performing a dry etch process on the semiconductor wafer with a dry etching apparatus that removes a reaction product inside a wafer lift pin hole using a cleaning jig having a return on its tip part.
2. The method for manufacturing a semiconductor device according to claim 1, wherein the reaction product is scraped out to the outside of the wafer lift pin hole by the return on the tip part of the cleaning jig.
3. The method for manufacturing a semiconductor device according to claim 2, wherein the cleaning jig has a through hole for sucking the reaction product that is scraped out and the reaction product that is scraped out is discharged to the outside of the wafer lift pin hole through the through hole.
4. The method for manufacturing a semiconductor device according to claim 2, wherein the cleaning jig has a through hole that supplies a solvent to the tip part of the cleaning jig, the solvent is supplied to the tip part through the through hole, and the reaction product inside the wafer lift pin hole is solved and removed by the solvent being jetted from the tip part.
5. The method for manufacturing a semiconductor device according to claim 1, wherein the cleaning jig is such that at least the tip part is formed of a material that is difficult to be electrified.
6. The method for manufacturing a semiconductor device according to claim 1, wherein the thin film is any of an aluminum film, a silicon oxide film, or a polysilicon film.
7. A semiconductor manufacturing apparatus comprising: a processing chamber that processes a semiconductor wafer; a stage that mounts the semiconductor wafer in the processing chamber; a through hole that is provided penetrating a front surface to a back surface of the stage; a wafer lift pin that is provided penetrating the inside of the through hole and moves the semiconductor wafer up and down; and a return that is provided inside the wafer lift pin and protrudes to the outside of the wafer lift pin by a predetermined operation.
8. The semiconductor manufacturing apparatus according to claim 7, wherein the wafer lift pin has a cramming part in a lower part of the wafer lift pin, makes the return protrude to the outside of the wafer lift pin by cramming the cramming part, and removes the reaction product adhering to the inside of the through hole by making the wafer lift pin move up and down.
9. The semiconductor manufacturing apparatus according to claim 8, wherein when the reaction product adhering to the inside of the through hole is removed by the return, a cycle purge where introduction of an inert gas to the processing chamber and evacuation of the processing chamber are repeated by turns is performed.
10. The semiconductor manufacturing apparatus according to claim 9, wherein when the wafer lift pin descends, an inert gas is introduced into the processing chamber, and when the wafer lift pin rises, the processing chamber is evacuated.
11. The semiconductor manufacturing apparatus according to claim 7, wherein the semiconductor manufacturing apparatus is any of a dry etching apparatus, a CVD apparatus, or a sputtering apparatus.
12. A wafer lift pin-hole cleaning jig that has a grip part on one end of the wafer lift pin-hole cleaning jig and has one or more returns on the other end of the wafer lift pin-hole cleaning jig.
13. The wafer lift pin-hole cleaning jig according to claim 12, wherein the wafer lift pin-hole cleaning jig has a through hole that penetrates from the one end to the other end.
14. The wafer lift pin-hole cleaning jig according to claim 12, wherein at least a part at which the return is provided is formed of a material that is difficult to be electrified.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(17) Hereinafter, examples are described using drawings. Incidentally, the same reference numeral is attached to the same configuration in each drawing, and a detailed explanation is omitted for an overlapping portion.
First Example
(18) First, a configuration of a processing chamber of a semiconductor manufacturing apparatus of this example and a problem around the lift pin are explained using
(19) As shown in
(20) The etching chamber EC is provided with a vacuum pumping system and a gas supply system that are not illustrated. After the etching chamber EC is vacuum evacuated, plasma is generated in the etching chamber EC by introducing a process gas into the etching chamber EC and applying a high-frequency power to the coil source CS.
(21) In the etching chamber EC, an electrostatic chuck ES (ESC: Electrostatic Chuck) for mounting and retaining a semiconductor wafer WF that is a target of dry etching processing is provided. This electrostatic chuck ES is also called a stage or a lower electrode because of its function to which an attention is paid. Moreover, for the electrostatic chuck ES, a base material of aluminum (Al) coated with ceramic containing a dielectric and the like are used.
(22) The electrostatic chuck ES has a structure in which a through hole penetrating from the front surface to the back surface is provided and the lift pin LP is driven up and down inside the through hole. This through hole is a lift pin hole LH.
(23) Under the electrostatic chuck ES, a retention mechanism for supporting the lift pin LP is provided. This retention mechanism is configured with a lift pin gripper LG for holding one end of the lift pin LP, a housing HS for covering and protecting a holding part of the lift pin LP, a base BS and a stem ST that support the lift pin gripper LG, etc. Incidentally, the lift pin gripper LG is formed, for example, of a heat resistant plastic like a polyimide resin. Moreover, the housing HS and the base BS are formed of stainless steel (SUS), and the stem ST is formed of a fluorocarbon resin, for example, respectively.
(24) The lift pin gripper LG is supported by a support arm called a lift pin spider LS through the stem ST and the base BS, and is driven up and down by an air cylinder AC.
(25) The lift pin LP is disposed penetrating the lift pin hole LH, and the lift pin guide LD is provided between the lift pin LP and the lift pin hole LH so that the lift pin LP may be driven up and down as perpendicularly as possible. The lift pin LP is formed of, for example, sapphire whose raw material is high-purity alumina (Al.sub.2O.sub.3). Moreover, the lift pin guide LD is formed of a heat-resistant plastic such as a polyimide resin.
(26) After conveying the semiconductor wafer WF into the etching chamber EC by an unillustrated wafer conveying arm, the lift pin LP rises and receives the semiconductor wafer WF from the wafer conveying arm. After the wafer conveying arm moves from the etching chamber EC, the lift pin LP that received the semiconductor wafer WF descends, and the semiconductor wafer WF is mounted on a surface of the electrostatic chuck ES. Incidentally, in order to prevent offset of the semiconductor wafer WF when the semiconductor wafer WF is mounted on the electrostatic chuck ES, an edge ring ER (wafer holding ring) formed of quartz, silicon, ceramics, or the like is disposed around the electrostatic chuck ES.
(27) Here, as described above, in the semiconductor manufacturing apparatuses, such as the dry etching apparatus, a CVD apparatus, and a sputtering apparatus, lift pin omission caused by reaction product deposited in the inside of the lift pin hole LH and around the lift pin gripper LG that is a support part of the lift pin LP becomes a problem.
(28) As shown in
(29) In addition to the problem shown in
(30) Then, if cleaning for removing the reaction product DP in the inside of the lift pin hole LH and around the lift pin gripper LG is tried to be performed, it is necessary to decompose the electrostatic chuck ES (lower electrode), which requires much labor and apparatus halt time in order to perform the cleaning.
(31) Therefore, how effectively the reaction product DP deposited in the inside of the lift pin hole LH and around the lift pin gripper LG can be discharged (removed) to the outside of the etching chamber EC has become an important problem for improving productivity of each semiconductor manufacturing apparatus and, therefore, productivity of a semiconductor manufacturing line.
(32) Next, a wafer lift pin-hole cleaning jig in this example is explained using
(33) The cleaning jig CJ in this example is formed to rod shape so as to be able to be inserted into the lift pin hole LH as shown in
(34) By providing the returns on the tip part of the cleaning jig CJ, in the case of periodic maintenance of the etching chamber EC, it is possible to insert the cleaning jig CJ after drawing out the lift pin LP from an upper surface side of an electrostatic chuck EC and to effectively scrape out (rake out) the reaction product deposited in the inside of the lift pin hole by the return BA to the outside of the lift pin hole.
(35) Incidentally, as shown in
(36) For example, when the width a of the portion of the lift pin guide LD is about 1.6 mm, the width (thickness) b of the return BA is formed in about 1.5 mm.
(37) In common semiconductor manufacturing apparatuses, since the thickness of the lift pin LP is the extent from 1.0 mm to 2.0 mm, a diameter of the lift pin hole LH (in this example, the width a of the portion of the lift pin guide LD) becomes the extent from 1.2 mm to 2.2 mm. Therefore, it becomes a standard to form the return BA of the cleaning jig CJ to have a diameter in the extent from 1.1 mm to 2.1 mm. However, numerical values shown here are merely illustrations, and the examples are not limited to these.
(38) Moreover, as for the material of the cleaning jig CJ, it is preferable to use what has sufficient strength, such as stainless steel (SUS), aluminum (Al), and a resin, so that the reaction product in the lift pin hole LH can be scraped out effectively.
(39) Furthermore, as for the material of the cleaning jig CJ, it is more preferable to use a material difficult to be electrified in order to prevent the reaction product that was scraped out with the cleaning jig CJ from adhering again to the lift pin guide LD and the inside of the lift pin holes LH due to static electricity. It is recommendable to form at least the tip part on which the return is provided of a material difficult to be electrified.
(40) As explained above, by using the cleaning jig CJ shown in
(41) Moreover, since the reaction product deposited in the lift pin hole LH can be removed without decomposing electrostatic chuck EC (lower electrode), it is possible to shorten the apparatus halt time considerably and to improve the productivity of the semiconductor manufacturing apparatus dramatically.
(42) A modification of the cleaning jig CJ is explained using
(43) A cleaning jig CJV with a suction hole shown in
(44) Incidentally, a relation of the width (thickness) d of the return BA and a width c of a portion of the lift pin guide LD that are shown in
(45) An action of the cleaning jig CJV with a suction hole is explained in more detail using
(46) Moreover, when the reaction product DP in the lift pin hole LH is scraped out with the return BA by making the cleaning jig CJV with a suction hole move up and down in the lift pin hole LH, the scraped-out reaction product DP can be sucked without dropping it from the tip part.
(47) Furthermore, the reaction product that failed to be sucked and fell around the lift pin gripper LG can also be sucked up by the cleaning jig CJV with a suction hole, and can be discharged to the outside.
(48) Another modification of the cleaning jig CJ is explained using
(49) By the solvent being jetted from the tip part of the cleaning jig CJS with a solvent supply hole into the lift pin hole LH, the reaction product DP can be dissolved and removed in a short time, and thereby the apparatus halt time can further be shortened.
(50) Incidentally, the solvent to be supplied is not limited to methanol, and should just be a solvent that can dissolve and remove the reaction product. Since a component of the reaction product is different with a kind of process that is the target of cleaning of the semiconductor manufacturing apparatus, a kind of the solvent is suitably selected and used according to the kind of process of the semiconductor manufacturing apparatus.
(51) Moreover, more effective cleaning can be attained by suitably selecting either jetting the solvent as it is in a liquid state or jetting it in a vaporous state after heating according to the kind of the solvent to be supplied and the component of the reaction product.
Second Example
(52) The semiconductor manufacturing apparatus in this example is explained using
(53) As shown in
(54) The cleaning mechanism CD has a structure in which the return BA of the cleaning jig CJ explained in the first example is embedded in the inside of the lift pin LP, and when cleaning the lift pin hole LH, the return protrudes to the outside of the lift pin LP by cramming the cramming part PP of the lower part of the lift pin LP, and scrapes out the reaction product deposited in the lift pin hole LH. The scraped-out reaction product falls and is discharged to the outside by evacuation of the apparatus.
(55) Incidentally, the scraped-out reaction product can be discharged to the outside of the apparatus more efficiently by using together cycle purging where evacuation of the etching chamber and introduction of the gas are repeated by turns. For the gas used for the cycle purging, the process gas used for process treatment of the semiconductor manufacturing apparatus and inert gases, such as nitrogen gas (N.sub.2), argon gas (Ar), and helium gas (He) are used.
(56) Moreover, when scraping out the reaction product in the lift pin hole LH by the cleaning mechanism CD and the cycle purging are performed simultaneously, the reaction product can be effectively discharged to the outside of the etching chamber by introducing the gas into the etching chamber when the lift pin LP descends and evacuating the atmosphere of the etching chamber when the lift pin LP rises.
(57) As explained above, according to the semiconductor manufacturing apparatus of this example, since the lift pin hole LH can be cleaned without opening the processing chamber (chamber) in the atmosphere, the apparatus halt time can further be shortened.
(58) Incidentally, although in the example, as an example of the cleaning mechanism, a structure in which the return is made to protrude to the outside of the lift pin LP by cramming the cramming part of the lower part of the lift pin LP as in
Third Example
(59) A method for manufacturing a semiconductor device in this example is explained using
(60) As shown in
(61) On each of various elements, a first wiring layer M1, a second wiring layer M2, a third wiring layer M3, a fourth wiring layer M4, a fifth wiring layer M5, a sixth wiring layer M6, and a wiring layer MH that is a top layer are formed sequentially from the lower layer. The each wiring layer is formed such that a wiring MW and a via VI are embedded in a lamination film consisting of an interlayer insulation film ID and an insulator film IF. For the first wiring layer M1 to the sixth wiring layer M6, copper (Cu) wiring and copper (Cu) via that are formed by a single damascene process or a dual damascene process are mainly adopted. Moreover, in a layer in which various elements such as a transistor are formed, in order to avoid contamination of the various elements by copper (Cu), contact CO of tungsten (W) is mainly used.
(62) In the wiring layer MH that is the top layer, a top layer wiring TM is formed on a tungsten (W) via TV in the circuit formation region. Moreover, in the pad disposition region, the pad electrode PD is formed on the tungsten (W) via TV. The top layer wiring TM and the pad electrode PD are mainly formed with an aluminum (Al) film. On the top layer wiring TM and the pad electrode PD, a passivation film (protective film) PF, such as a polyimide resin, is formed so as to cover upper surfaces of the top layer wiring TM and the pad electrode PD. Incidentally, a part of the passivation film (protective film) PF on the pad electrode PD is removed and the part of the pad electrode PD is exposed to the surface.
(63) Since a relatively large current flows through these top layer wiring TM and pad electrode PD, they are formed with thick film thicknesses. For example, in the case of a 45 m-process generation's product, they are in the extent from 1.5 m to 2.0 m. These top layer wiring TM and pad electrode PD are subjected to the dry etching processing by the dry etching apparatus after an aluminum (Al) film was formed on the interlayer insulation film ID that was the top layer by a sputtering apparatus, and are processed into the top layer wiring TM and the pad electrode PD. Since the aluminum (Al) film whose film thickness is thick is used for the top layer wiring TM and the pad electrode PD, a time of the dry etching processing becomes long and an amount of the reaction product generated in the etching chamber of the dry etching apparatus also becomes large.
(64) Therefore, the amount of the reaction product deposited in the lift pin hole LH in the etching chamber also becomes large, and the lift pin omission caused by adhesion of the reaction product (deposition material) that was explained in
(65) Then, at the time of the periodic maintenance of the dry etching apparatus that is used when the top layer wiring TM and the pad electrode PD are processed, it becomes possible to shorten the halt time of the dry etching apparatus considerably by using the cleaning jig CJ, the cleaning jig CJV with a suction hole, or the cleaning jig CJS with a solvent supply hole that were explained in the first example. Thereby, productivity of the semiconductor manufacturing line improves dramatically.
(66) Moreover, the dry etching apparatus including the lift pin-hole cleaning mechanism explained in the second example can be used for the dry etching processing of an aluminum (Al) film, which can improve the productivity of the semiconductor manufacturing line similarly.
(67) A formation flow of the top layer wiring TM and the pad electrode PD explained above is shown in
(68) First, an aluminum (Al) film AF is formed on the interlayer insulation film ID that is the top layer in which a tungsten via TV was formed. (
(69) Next, a desired circuit pattern (here, a pattern of the top layer wiring TM and the pad electrode PD) is transferred to the photoresist film PR by photolithography, and the photoresist film is subjected to a developing process to form a mask pattern of the photoresist film PR. (
(70) Following this, the aluminum (Al) film AF is subjected to the dry etching processing by the dry etching apparatus using the mask pattern of the photoresist film PR as a dry etching mask to remove excessive aluminum (Al) film AF. When a thin film to be etched is an aluminum (Al) film, a mixed gas of chlorine (Cl.sub.2)/boron trichloride (BCl.sub.3) is mainly used as the process gas for this dry etching processing. (
(71) Here, as explained above, the dry etching processing of an aluminum (Al) film thick in film thickness as in the case of the top layer wiring TM or the pad electrode PD takes a long processing time. Accordingly, the dry etching apparatus in which the reaction product inside a wafer lift pin hole was removed using the cleaning jig having a return in the tip part that was explained in the first example is used for the dry etching of this aluminum (Al) film. Alternatively, the dry etching apparatus including the lift pin-hole cleaning mechanism explained in the second example is used.
(72) Finally, the top layer wiring TM and the pad electrode PD are formed by performing an asking treatment with oxygen (O.sub.2) plasma, etc. on the mask pattern (photoresist film PR) that remains without being etched. (
(73) As explained above, according to the method for manufacturing a semiconductor device of this example, it is possible to shorten the apparatus halt time by the periodic maintenance of the semiconductor manufacturing apparatus that is represented by the dry etching apparatus, and to improve the productivity of the semiconductor manufacturing line dramatically.
(74) Incidentally, in the third example, although the target semiconductor manufacturing apparatus is shown by the example of the dry etching apparatus and the target process is illustrated by the dry etching process of the aluminum (Al) film, the semiconductor manufacturing apparatus and the method for manufacturing a semiconductor device are not limited to these.
(75) A target semiconductor manufacturing apparatus should be any apparatus that uses the similar wafer lift pin structure, and for example, a CVD apparatus, a sputtering apparatus, and the like can become targets. Moreover, regarding the target process, in addition to the dry etching process of the aluminum (Al) film, the method for manufacturing a semiconductor device can acquire the same effect by using the method in the dry etching process of silicon oxide (SiO.sub.2 film) and polysilicon film (Poly-Si film) in which much reaction product is generated in the chamber (processing chamber).
(76) In the above, although the invention made by the present inventors was concretely explained based on the embodiments, it is needless to say that the present invention is not limited to the embodiments and can be varied variously without deviating from the scope of the present invention.
REFERENCE SIGNS LIST
(77) EC: Etching chamber,
(78) RG: RF generator,
(79) CS: Coil source,
(80) ES: Electrostatic chuck (ESC),
(81) LP: Lift pin,
(82) HS: Housing,
(83) LG: Lift pin gripper,
(84) BS: Base,
(85) ST: Stem,
(86) LD: Lift pin guide,
(87) LH: Lift pin hole,
(88) LS: Lift pin spider,
(89) AC: Air cylinder,
(90) ER: Edge ring,
(91) WF: Wafer,
(92) DP: Reaction product,
(93) CJ: Cleaning jig,
(94) HP: Holding part,
(95) BA: Return
(96) CJV: Cleaning jig with suction hole,
(97) VH: Suction hole,
(98) CJS: Cleaning jig with solvent supply hole,
(99) SH: Solvent supply hole,
(100) PP: Cramming part,
(101) CD: Cleaning mechanism,
(102) SS: Semiconductor substrate,
(103) DL: Diffusion layer,
(104) GE: Gate electrode,
(105) CO: Contact,
(106) ID: Interlayer insulation film,
(107) IF: Insulator film,
(108) MW: Wiring,
(109) VI: Via,
(110) PF: Passivation film (protective film),
(111) PD: Pad electrode,
(112) TV: Tungsten (W) via,
(113) TM: Wiring on top layer
(114) M1: First wiring layer,
(115) M2: Second wiring layer,
(116) M3: Third wiring layer,
(117) M4: Fourth wiring layer,
(118) M5: Fifth wiring layer,
(119) M6: Sixth wiring layer,
(120) MH: Wiring layer on top layer,
(121) AF: Aluminum (Al) film,
(122) PR: Photoresist film.