SEMICONDUCTOR CHIP, SOLID-STATE IMAGING DEVICE, AND ELECTRONIC EQUIPMENT
20250031475 ยท 2025-01-23
Assignee
Inventors
Cpc classification
H01L2224/80895
ELECTRICITY
H01L2224/80896
ELECTRICITY
International classification
Abstract
Provided is a semiconductor chip, a solid-state imaging device, and electronic equipment which achieve further reduction in thickness of a silicon substrate, required for 3D staking and which have a structure with no effect on device characteristics. Such a configuration having a first semiconductor chip including photodiodes, a second semiconductor chip including a signal processing circuit from the photodiodes and which is stacked on the first semiconductor chip, a first insulating film which is stacked on a second surface of the second semiconductor chip that is opposite to a first surface thereof having the first semiconductor chip stacked thereon and which includes oxygen, and a second insulating film which is stacked on the first insulating film and which includes oxygen are made, thereby preventing occurrence of leakage at a depletion layer of a transistor in the semiconductor chip and achieving reduction in film thickness.
Claims
1. A solid-state imaging device, comprising: a first semiconductor chip including photodiodes; a second semiconductor chip including a signal processing circuit from the photodiodes and which is stacked on the first semiconductor chip; a first insulating film which is stacked on a second surface of the second semiconductor chip that is opposite to a first surface thereof having the first semiconductor chip stacked thereon and which includes oxygen; and a second insulating film stacked on the first insulating film and including oxygen.
2. The solid-state imaging device according to claim 1, wherein the second insulating film includes a High-k dielectric having an oxygen surface density different from the first insulating film.
3. The solid-state imaging device according to claim 1, wherein the second insulating film stacked on the first insulating film includes a negative insulating film or a positive insulating film.
4. The solid-state imaging device according to claim 1, wherein a third insulating film including a High-k dielectric is stacked on the second insulating film.
5. The solid-state imaging device according to claim 1, wherein the second insulating film includes hafnium oxide (HfO.sub.2), aluminum oxide (Al.sub.2O.sub.3), zirconium oxide (ZrO.sub.2), tantalum pentoxide (TazO.sub.5), titanium oxide (TiO.sub.2), lanthanum oxide (La.sub.2O.sub.3), or yttrium oxide (Y.sub.2O.sub.3).
6. The solid-state imaging device according to claim 1, wherein the second insulating film is stacked on a buried oxide film layer.
7. The solid-state imaging device according to claim 1, comprising: a third semiconductor chip having a semiconductor active element and in which the first insulating film and the second insulating film are stacked, in the first semiconductor chip or the second semiconductor chip.
8. The solid-state imaging device according to claim 1, wherein two or more semiconductor chips are stacked on the first semiconductor chip.
9. A solid-state imaging device, comprising: a semiconductor chip including photodiodes; a first insulating film stacked on an upper surface of the photodiodes on a light incidence surface side of the semiconductor chip and including oxygen; and a negative or a positive second insulating film stacked on the first insulating film and including oxygen.
10. A semiconductor chip, comprising: a substrate having a polished surface; a first insulating film formed on the polished surface and including oxygen; a second insulating film stacked on the first insulating film and including oxygen; and a semiconductor active element.
11. The semiconductor chip according to claim 10, wherein a second semiconductor chip is bonded to a surface that is opposite to the polished surface.
12. Electronic equipment, comprising: a solid-state imaging device including a first semiconductor chip including photodiodes, a second semiconductor chip including a signal processing circuit from the photodiodes and which is stacked on the first semiconductor chip, a first insulating film which is stacked on a second surface of the second semiconductor chip that is opposite to a first surface thereof having the first semiconductor chip stacked thereon and which includes oxygen, and a second insulating film stacked on the first insulating film and including oxygen; or a semiconductor chip including a polished surface, a first insulating film stacked on the polished surface and including oxygen, a second insulating film stacked on the first insulating film and including oxygen, and a semiconductor active element.
Description
BRIEF DESCRIPTION OF DRAWINGS
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DESCRIPTION OF EMBODIMENTS
[0044] Hereinafter, modes for carrying out the present disclosure (hereinafter referred to as embodiments) will be described in the following order with reference to the accompanying drawings. In the drawings, identical or similar parts will be denoted by the same or similar reference signs. Since the drawings are schematically illustrated, it should be noted that ratios of dimensions of respective sections or the like do not necessarily coincide with the actual ones. It goes without saying that the drawings are sometimes different from each other in dimensional relation or ratio. [0045] 1. First embodiment of solid-state imaging device according to present disclosure [0046] 2. Basic form of second embodiment of solid-state imaging device according to present disclosure [0047] 3. First modification example of second embodiment of solid-state imaging device according to present disclosure [0048] 4. Second modification example of second embodiment of solid-state imaging device according to present disclosure [0049] 5. Third embodiment of solid-state imaging device according to present disclosure [0050] 6. Fourth embodiment of solid-state imaging device of present disclosure [0051] 7. Fifth embodiment of solid-state imaging device according to present disclosure [0052] 8. Sixth embodiment of solid-state imaging device according to present disclosure [0053] 9. Method of manufacturing solid-state imaging device according to present disclosure [0054] 10. Configuration example of electronic equipment
1. First Embodiment of Solid-State Imaging Device According to Present Disclosure
(Configuration of First Embodiment)
[0055] Hereinafter, with reference to
[0056] The CIS chip 101 has a photodiode formation layer 116 having a plurality of photodiodes 113 formed therein, and a wiring layer 114 for wiring the photodiodes, for example, as illustrated in
[0057] The support substrate 103 is a silicon film constituting a base plate of the solid-state imaging device 10. The support substrate 103 has two semiconductor chips such as the logic chips 102-1 and 102-2 stacked thereon. The logic chips 102-1 and 102-2 have a logic circuit, a memory circuit (both not illustrated), and the like formed therein. The logic circuit is, for example, a vertical drive section, a horizontal drive section, a system control section, a signal processing section, or the like for sequentially reading out image data of each pixel including the photodiode 113. In addition, the memory circuit is, for example, a data storing section or the like which temporarily stores data necessary for processing by the signal processing section. These logic circuits are accommodated by being divided into the logic chips 102-1 and 102-2.
[0058] Note that, in the following description, the logic chip and the memory chip are collectively denoted as a logic chip for description.
[0059] The logic chip 102-1 has a transistor 123-1 disposed on a silicon substrate 105-1. Also, above the transistor 123-1, a multilayer wiring layer 104 in which an interlayer insulating film is formed is disposed, and each wiring layer in the multilayer wiring layer 104 has a wire 122 formed therein, and the wire 122 includes a half of circuits such as the vertical drive section and the horizontal drive section described above. In addition, the upper and lower sides of the wires 122 are connected to each other through vias 125 in an up-down direction (in a vertical direction in
[0060] In the logic chip 102-2, the rest of the logic circuits which are not accommodated in the logic chip 102-1 is formed on a silicon substrate 105-2. More specifically, as in the logic chip 102-1, a transistor 123-2 is disposed on the silicon substrate 105-2. Also, above the transistor 123-2, the multilayer wiring layer 104 in which the interlayer insulating film is formed is disposed, and each of the wiring layers in the multilayer wiring layer 104 has the wire 122 formed therein, and the wire 122 includes the circuits such as the vertical drive section and the horizontal drive section. In addition, the upper and lower sides of the wires 122 are connected to each other, as in the logic chip 102-1. Moreover, the logic chips 102-1 and 102-2 are insulated from each other with an insulating film 109 interposed therebetween.
[0061] Note that, in
[0062] The logic chips 102-1 and 102-2 have respective pads 121 formed therein on a side where the CIS chip 101 is bonded to each of the logic chips 102-1 and 102-2, the pads 121 being conductors such as copper (Cu). In addition, the CIS chip 101 similarly has pads 115 formed therein on such a side as to be bonded to each of the logic chips 102-1 and 102-2, the pads 115 being conductors such as copper (Cu). Then, the pad 115 and the pad 121 are disposed so as to be opposed to each other on the side where they are bonded to each other.
[0063] Accordingly, when the CIS chip 101 is stacked on the logic chips 102-1 and 102-2, the respective pads 121 formed in the logic chips 102-1 and 102-2 are bonded to the respective pads 115 disposed to be opposed thereto by CuCu bonding at the bonding surface 160.
[0064] Since the pad 121 and the pad 115 each include the conductor such as copper (Cu), the circuits formed in the CIS chip 101 and the circuits formed in the logic chip 102 are electrically connected with each other by CuCu bonding between the pads 115 and the corresponding pads 121 at the bonding surface 160, thereby forming circuits.
[0065] Note that it is sufficient if only the required number of pads 115 and only the required number of pads 121 are provided at positions required to connect the circuits formed in the CIS chip 101 with the circuits formed in the logic chips 102-1 and 102-2.
(Actions of Oxide Film and Charged Film)
[0066] As illustrated in
[0067] The oxide film 131 and the charged film 132 prevent the occurrence of leakage at the depletion layer 161 attributable to polishing of the lower surface of the silicon substrate 105-1. This will be described below.
[0068]
[0069] Incidentally, in
[0070] However, as illustrated in FIG, 2, if the film thickness d1 is formed to be thick, a distance between the N well (N-well) 152 in the P-type transistor 123 disposed on the upper surface of the silicon substrate 105 and the defect 162 becomes large. Hence, the depletion layer 161 of the transistor 123 does not reach the defect 162. Accordingly, there is no possibility that the electrons 164 caught by the defects 162 enter the depletion layer 161, thereby causing leakage from the depletion layer 161. This similarly applies to a case in which the transistor 123 disposed on the upper surface of the silicon substrate 105 is an N type.
[0071]
[0072] As illustrated in
[0073]
[0074] Accordingly, when a certain High-k dielectric is stacked on the silicon dioxide, polarization occurs in both films due to a difference in oxygen surface density. Specifically, a force of oxygen for moving from an insulator with a larger oxygen surface density to an insulator with a smaller oxygen surface density acts. However, silicon dioxide and the High-k dielectric are insulators (dielectrics), and accordingly, movement of the electrons 164 and the holes 163 are restricted, so that they are not able to freely move in the insulators. Owing to this, according to the difference in oxygen surface density of both of the insulators, migration (displacement) of negative charges occurs, and a dipole 166 is generated, as illustrated in
[0075] A magnitude of polarization varies depending on an oxygen surface density of each of silicon dioxide and the High-k dielectric. Owing to this, the charged film 132 including the High-k dielectric with a predetermined oxygen surface density is stacked on the oxide film 131, positive or negative charges appear in the charged film 132 and the oxide film 131, according to the difference in oxygen surface density between both of the films.
[0076] For example, the charged film 132 including the High-k dielectric with a lower oxygen surface density than that of silicon dioxide is stacked on the oxide film 131 including silicon dioxide, as illustrated in
[0077]
[0078] Accordingly, an orientation of an electric field outside the oxide film 131 also becomes an opposite direction to that of the internal electric field 165. Owing to this, the positive charges are induced at the upper surface (front surface) of the oxide film 131 and for example, recombined with the electrons 164 caught in the defects or may be less likely to be caught in the defects 162.
[0079] In the example of
[0080] In the example of
[0081] As such, in a case in which a positive charged film is formed, the orientation of the internal electric field 165 due to the polarization becomes an opposite direction relative to the direction indicated in
[0082] The charged film 132 including a High-k dielectric serving as the second insulating film can include, for example, hafnium oxide (HfO.sub.2), aluminum oxide (Al.sub.2O.sub.3), zirconium oxide (ZrO.sub.2), tantalum pentoxide (Ta.sub.2O.sub.5), titanium oxide (TiO.sub.2), lanthanum oxide (La.sub.2O.sub.3), or yttrium oxide (Y.sub.2O.sub.3). Specifically, the charged film 132 is, for example, a film formed by at least any one material selected from these materials.
[0083] In these High-k dielectrics, for example, hafnium oxide and aluminum oxide are larger in oxygen surface density than silicon dioxide forming the oxide film 131. Accordingly, when these materials are used for the charged film 132, the charged film 132 side is positively polarized, and the oxide film 131 side is negatively polarized. Hence, these High-k dielectrics become the negative charged film 132.
[0084] In addition, for example, lanthanum oxide and yttrium oxide are smaller in oxygen surface density than silicon dioxide forming the oxide film 131, and accordingly, when these materials are used for the charged film 132, the charged film 132 side is negatively polarized, the oxide film 131 side is positively polarized. Hence, these High-k dielectrics become a positive charged film.
(Application Example of Present Embodiment and Effect)
[0085] As is described above, the oxide film 131 and the charged film 132 are stacked on the lower surface (polished surface) of the silicon substrate 105, so that the electron 164 or the hole 163 that is present in the defect 162 attributable to polishing or contamination can be caught in the oxide film 131, thereby allowing the silicon substrate 105 to be thinned without generating leakage.
[0086] In addition, as illustrated in
[0087] As a result, it is possible to bond the two logic chips 102-1 and 102-2 to the one CIS chip 101. In addition, the logic chip 102-1 has the oxide film 131 and the charged film 132 stacked thereon, and the logic chip 102-2 may not have them stacked thereon. Consequently, in a case in which both the logic chips 102-1 and 102-2 are different in thickness, the logic chip 102 having a greater thickness is polished, and it is possible to bond the two logic chips 102-1 and 102-2 to the one CIS chip 101 in a state in which the thicknesses of both of the films are made to be uniform by stacking the oxide film 131 and the charged film 132 on the polished surface.
[0088] Thus, it is permissible that the logic chip 102-1 having the oxide film 131 and the charged film 132 stacked thereon and the logic chip 102-2 having no films stacked thereon may be present in a mixed manner.
[0089] In addition, the logic chip may be only the logic chip 102-1 having the oxide film 131 and the charged film 132 stacked thereon. Alternatively, multiple number of logic chips 102-1 and 102-2 may be present in a mixed manner.
[0090] As described above, according to the present embodiment, the oxide film 131 including silicon dioxide and the charged film 132 including the High-k dielectric are stacked on the polished surface of the silicon substrate 105. Consequently, it is possible to prevent occurrence of leakage caused by the electron 164 or the hole 163 entering the depletion layer 161, the electron 164 or the hole 163 being present in the defect 162 generated in the vicinity of the polished surface due to polishing or contamination. Further, it is possible to achieve reduction in film thickness of the silicon substrate 105, reduction in height and size of the solid-state imaging device 10, and higher integration of the solid-state imaging device 10.
2. Basic Form of Second Embodiment of Solid-State Imaging Device According to Present Disclosure
[0091] Next, with reference to
[0092]
[0093] As illustrated in
[0094] On the support substrate 103, as illustrated in
[0095] The logic chip 102-1 has the logic circuits formed in the multilayer wiring layer 104 on the silicon substrate 105. Specifically, on the silicon substrate 105, the transistor 123-1 is disposed. Also, above the transistor 123-1, the multilayer wiring layer 104 is disposed, and each wiring layer thereof has the wire 122 formed therein, the wire 122 including the rest of the circuits such as any of the vertical drive section, the horizontal drive section, and the like which are described above. In addition, the upper and lower sides of the wires 122 are connected through the vias 125 in the up-down direction (the vertical direction in
[0096] The transistor 123-1 in
[0097] The oxide film 131 is stacked on the lower surface of the silicon substrate 105, and further, the charged film 132 is stacked on the lower surface of the oxide film 131. Since actions of the oxide film 131 and the charged film 132 are similar to those in the first embodiment, description thereof will be omitted. Note that the transistors 123-0 and 123-2 also have the P+ diffusion layers 154 and the N well 152 as in the first embodiment, and illustration and description thereof will be omitted for simplification. In the following, the same applies to the similar cases.
[0098] The logic chip 102-1 and the CIS chip 101 are bonded to each other by CuCu bonding in a face-to-face manner. The logic chip 102-1 and the CIS chip 101 have respective pads 121 and 115 necessary for CuCu bonding formed therein. Description of the CuCu bonding between the logic chip 102 and the CIS chip 101 will be omitted since it is similar to that in the first embodiment.
[0099] The logic chip 102-1 and the logic chip 102-2 are connected in a back-to-face (B2F) manner. Specifically, since the upper surface of the logic chip 102-1 is bonded to the CIS chip 101, the lower surface of the logic chip 102-1 is required to be connected to the logic chip 102-2.
[0100] More specifically, below the multilayer wiring layer 104 in which the circuits of the logic chip 102-1 are formed, the silicon substrate 105 is present. Owing to this configuration, the logic chip 102-1 and the 102-2 are not able to be connected to each other by CuCu bonding. In view of this, the silicon substrate 105, the charged film 132, and the oxide film 131 have a TSV 411 formed therethrough. The TSV 411 connects the wire 122 constituting the circuits of the logic chip 102-2 with the wire 122 constituting the circuits of the logic chip 102-1 on the upper side thereof.
[0101] As such, in the lower surface of the silicon substrate 105, that is, in the surface on which the oxide film 131 and the charged film 132 are stacked, a lower end of the TSV 411 is opened. This opening has a pad 121-1 formed therein. Meanwhile, in the upper surface of the logic chip 102-2, a pad 121-2 is formed at a position corresponding to the opening of the TSV 411 in such a manner as to face the pad 121-1.
[0102] Accordingly, the pads 121-1 and 121-2 formed in the respective logic chips 102-1 and 102-2 are opposed to each other, thereby achieving CuCu bonding therebetween at the bonding surface 160.
[0103] As described above, the oxide film 131 including silicon dioxide and the charged film 132 including the High-k dielectric are stacked on the polished surface serving as the lower surface of the silicon substrate 105. With this configuration, the electron 164 or the hole 163 that is present in the defect 162 generated in the vicinity of the polished surface due to polishing or contamination is drawn to the front surface of the oxide film 131. Consequently, occurrence of leakage caused by the electron 164 or the hole 163 entering the depletion layer 161 can be eliminated. Moreover, not only thinning of the silicon substrate 105, but also reduction in height of the solid-state imaging device 10 can be achieved.
[0104] In addition, since such a three-layered configuration described above makes it possible to perform CuCu bonding between the individual chips, bonding of three wafers with one another is enabled. In particular, the logic chips 102-1 and 102-2 can be formed with a reduced thickness, allowing the height of the TSV to be small, so that the diameter of the TSV can be made small in association with the reduced height of the TSV. In addition, this enables an increased effective area of the chip, so that reduction in height and size of the solid-state imaging device 10 and higher integration thereof can be achieved.
3. First Modification Example of Second Embodiment of Solid-State Imaging Device According to Present Disclosure
[0105] Next, with reference to
[0106] The present first modification example and the basic form of the second embodiment differ from each other in that, while the negative charged film 132 and the oxide film 131 are stacked in one layer each in the basic form, for example, two charged films 132-1 and 132-2 having the same type of polarity, positive or negative, are stacked as illustrated in
[0107] Stacking the two charged films 132-1 and 132-2 in the manner described above can further improve an effect of preventing occurrence of leakage caused by the defect 162 and the like generated in the polished surface.
4. Second Modification Example of Second Embodiment of Solid-State Imaging Device According to Present Disclosure
[0108] Next, with reference to
[0109] The present second modification example and the basic form of the second embodiment differ from each other in that, while one type of the charged film 132 is stacked on the oxide film 131 in the basis form, two types of charged films, the negative charged film 132 and a positive charged film 133, are stacked on the oxide film 131 such that respective stacked regions of the negative charged film 132 and the positive charged film 133 are separated from each other in the present second modification example, as illustrated in
[0110] In addition, the transistor 123-1 is a P-type transistor, and the transistor 123-2 is an N-type transistor. Also, stacking the charged film 132 on the oxide film 131 on the lower surface of the transistor 123-1 forms the negative charged film 132. In addition, stacking the charged film 133 on the oxide film 131 on the lower surface of the transistor 123-2 forms the positive charged film 133.
[0111] According to the modification example of the present embodiment, the charged films 132 and 133 having different polarities can be mixed in one semiconductor chip, different types of semiconductor elements can be integrated in one semiconductor chip, thereby achieving a higher integration degree.
[0112] The configurations other than those described above are similar to those in the basic form of the second embodiment, and accordingly, description thereof will be omitted.
5. Third Embodiment of Solid-State Imaging Device According to Present Disclosure
[0113] Next, with reference to
[0114] The solid-state imaging device 10 according to the present third embodiment has the logic chip 102 stacked on the support substrate 103, and the logic chip 102 has the monolithic chip 106 incorporated therein, as illustrated in
[0115] As illustrated in
[0116] The logic chip 102 has the transistor 123-2 disposed therein and has circuits formed therein. In this case, the circuits of the transistor 123-1 on the monolithic chip 106 and the circuits of the transistor 123-2 in the logic chip 102 are connected to each other through the via 125, the wire 122-1, and the TSV 411-1.
[0117] The logic chip 102 and the CIS chip 101 have respective pads 121 and 115 necessary for performing CuCu bonding formed therein, as in the first embodiment. The logic chip 102 and the CIS chip 101 are connected to each other in a face-to-face manner through CuCu bonding of the pads 121 and 115. Thus, the circuits of the transistor 123-2 are connected to the pad 121 through the TSV 411-2.
[0118] With this configuration, it is possible to reduce the monolithic chip 106 in its film thickness to be incorporated in the logic chip 102.
[0119] As described above, the oxide film 131 including silicon dioxide or the like and the charged film 132 including the High-k dielectric are stacked on the lower surface (polished surface) of the silicon substrate 105. This configuration makes it possible to prevent occurrence of leakage at the depletion layer 161. In addition, reduction in film thickness of the silicon substrate 105 resulting from reduction in film thickness of the monolithic chip 106 can achieve reduction in height of the solid-state imaging device 10 and a higher integration thereof.
[0120] In addition, since the monolithic chip 106 can be incorporated in the logic chip 102 and CuCu bonding can be made between the CIS chip 101 and the logic chip 102, thereby allowing implementation of CoW or WoW. Hence, reduction in height and size of the solid-state imaging device 10 and a higher integration thereof can be achieved.
6. Fourth Embodiment of Solid-State Imaging Device of Present Disclosure
[0121] Next, with reference to
[0122] On the light incidence surface side of the CSI chip 101, as described in the first embodiment, in order to form the photodiode 113 after the photodiode formation layer 116 is formed to be thin by polishing, the defect 162 is generated in the vicinity of the polished surface due to polishing or contamination. Owing to this, the electron 164 or the hole 163 that is present in the defect 162 enters the depletion layer 161 of the transistor 123-0, possibly causing occurrence of leakage.
[0123] In view of this, as illustrated in
[0124] According to the configuration of the present embodiment described above, the photodiode formation layer 116 can be reduced in its film thickness, and occurrence of leakage can be prevented. Accordingly, the solid-state imaging device 10 can be operated stably, thereby realizing high quality of the solid-state imaging device 10.
7. Fifth Embodiment of Solid-State Imaging Device According to Present Disclosure
[0125] Next, with reference to
[0126] As illustrated in
[0127] More specifically, as illustrated in
[0128] As illustrated in
[0129] As illustrated in
[0130] Next, the wires between the chips will be described. As illustrated in
[0131] The transistor 123-1 of the logic chip 102-1 is connected with the support substrate 103 through the via 125, the wire 122-1, and the TSV 411-1. The TSV 411-1 may further be connected with the solder ball 107 through the TSV (not illustrated) in the support substrate 103.
[0132] The transistor 123-2 of the logic chip 102-2 is connected with a wire 122-2 through the via 125. Although illustration is not provided in
[0133] As described above, the oxide film 131 including silicon dioxide or the like and the charged film 132 including the High-k dielectric are stacked on the lower surface (polished surface) of each of the silicon substrates 105-1, 105-2, and 105-3. Accordingly, it is possible to prevent occurrence of leakage at the depletion layer 161 of each of the transistors 123-1, 123-2, and 123-3. Moreover, since the silicon substrate 105 can be reduced in film thickness, the logic chips 102-1, 102-2, and 102-3 can be reduced in film thickness. Hence, reduction in height and size of the solid-state imaging device 10 and higher integration thereof can be achieved.
[0134] In addition, the present embodiment can be used as the logic chip 102 of the solid-state imaging device 10 as a matter of course and is not limited to the solid-state imaging device 10. For example, stacking a plurality of semiconductor chips having other functions in multiple layers onto the logic chip 102 according to the present embodiment makes it possible to form a semiconductor device with high integration for other usages. Since the logic chip 102 according to the present embodiment in this manner has rich versatility, it is applicable to a semiconductor element other than the solid-state imaging device 10, the semiconductor element being used for every types of electronic equipment or industrial equipment.
8. Sixth Embodiment of Solid-State Imaging Device According to Present Disclosure
[0135] Next, with reference to
[0136] The solid-state imaging device 10 according to the present embodiment includes the logic chip 102 illustrated in
[0137] More specifically, as illustrated in
[0138] The transistor 123-2 is an N-type transistor, and a drain and a source thereof have N+ diffusion layers 153 formed therein. Of these N+diffusion layers 153, the right N+ diffusion layer 153 is connected to each circuit through the via 125 and the wire 122. In addition, the P well 151 is formed on the periphery of the N+ diffusion layers 153 in the silicon substrate 105.
[0139] In addition, above the transistors 123-1 and 123-2, the multilayer wiring layer 104 is disposed. Each wiring layer of the multilayer wiring layer 104 has the wire 122 constituting a predetermined circuit formed therein, and the upper and lower sides of the wires 122 are connected through the vias 125 in the up-down direction (the vertical direction in
[0140] Also, the oxide film 131 is stacked on the lower surface (polished surface) of the silicon substrate 105 on which the P-type transistor 123-1 and the N-type transistor 123-2 are disposed, and the charged film 132 is further stacked on the oxide film 131. Note that, as described in
[0141] As described above, the oxide film 131 including silicon dioxide or the like and the negative charged film 132 including the High-k dielectric or the positive charged film 133 are stacked on the lower surface (polished surface) of the silicon substrate 105. Hence, it is possible to prevent occurrence of leakage at the depletion layer 161 of the P-type transistor 123-1 or the N-type transistor 123-2. Moreover, reduction of the film thickness of the silicon substrate 105 enables the logic chip 102 to be reduced in film thickness. As a result of this, reduction in height and size of the solid-state imaging device 10 and higher integration thereof can be achieved.
[0142] In addition, the logic chip 102 according to the present embodiment is used as the logic chip 102 of the solid-state imaging device 10 as a matter of course and is not limited to the solid-state imaging device 10. For example, stacking a plurality of semiconductor chips having other functions in multiple layers onto the logic chip 102 according to the present embodiment makes it possible to form a semiconductor device with high integration for other usages. Since the logic chip 102 according to the present embodiment in this manner has rich versatility, it is applicable to a semiconductor element other than the solid-state imaging device 10, the semiconductor element being used for every types of electronic equipment or industrial equipment.
9. Method of Manufacturing Solid-State Imaging Device According to Present Disclosure
[0143] Next, a method of manufacturing the solid-state imaging device 10 according to the present disclosure will be described, taking as an example the basic form of the second embodiment of the first to the sixth embodiments, with reference to
[0144] First, as illustrated in
[0145] In addition, concurrently with this, as illustrated in
[0146] The BOX layer 108 is an insulator that separates the active element region (SOI: Silicon on Insulator) such as the transistor 123. For example, as illustrated in
[0147] In this case, a lower surface of the silicon chip 105-1 illustrated in
[0148] Next, the photodiode formation layer 116 of the CIS chip 101 illustrated in
[0149] Similarly, the silicon substrate 105 of the logic chip 102-1 illustrated in
[0150] Alternatively, in place of the logic chip 102-1, the lower surface of the silicon substrate 105-1 illustrated in
[0151] Next, as illustrated in
[0152] As for bonding, the pads 115 and 121 are formed in advance in the CIS chip 101 and the logic chip 102-1 or the logic chip 102-1 having the BOX layer 108, respectively, and the corresponding pads 115 and 121 are connected with each other by CuCu bonding at the bonding surface 160.
[0153] Next, as illustrated in
[0154] In addition, in another step, as illustrated in
[0155] Next, as illustrated in
[0156] Next, the TSV 411 is formed so as to penetrate the thin silicon layer formed as described above, the charged film 132, the oxide film 131, and the silicon substrate 105 from the lower side of the logic chip 102-1, and an opening of the TSV 411 has the pad 121-1 formed therein. Then, the pad 121-1 formed in the opening of the TSV 411 and the pad 121-2 of the logic chip 102-2 prepared in
[0157] Next, as illustrated in
[0158] Through the steps described above, the solid-state imaging device 10 can be manufactured.
[0159] Although the manufacturing process described above has been described taking the basic form of the second embodiment as an example, it is possible to manufacture the solid-state imaging device 10 also in another embodiment by adding some modifications to the manufacturing process of the present description.
10. Configuration Example of Electronic Equipment
[0160] An application example of the solid-state imaging device 10 according to the foregoing embodiments to electronic equipment will be described with reference to
[0161] The solid-state imaging device 10 is applicable to electronic equipment in general using an image pickup unit (photoelectric conversion unit), such as an imaging device 200 like a digital still camera or a video camera, a portable terminal device having an imaging function, and a copying machine including the solid-state imaging device 10 as an image reading unit. The solid-state imaging device 10 may have a one-chip form or may be a packaged solid-state imaging device. Alternatively, the solid-state imaging device 10 may have a module-shaped form having an imaging function as a package collectively including an imaging unit and a signal processing unit or an optical system.
[0162] As depicted in
[0163] The optical unit 202 includes multiple lenses and captures incident light (image light) coming from a subject, to form an image of the incident light on an imaging plane of the solid-state imaging device 10. After the image of the incident light is formed on the imaging plane by the optical unit 202, the solid-state imaging device 10 converts light quantities of the incident light into electric signals for each pixel and outputs the electric signals as pixel signals.
[0164] For example, the display unit 205 includes a panel-type display device such as a liquid crystal panel and an organic EL (Electro Luminescence) panel and displays moving images or still images captured by the solid-state imaging device 10. The recording unit 206 records the moving images or the still images captured by the solid-state imaging device 10 in a recording medium such as a hard disk and a semiconductor memory.
[0165] The operation unit 207 issues operation commands associated with various functions of the imaging device 200 under operation by a user. The power source unit 208 appropriately supplies various types of power sources corresponding to operation power sources for the DSP circuit 203, the frame memory 204, the display unit 205, the recording unit 206, and the operation unit 207 to these supply targets.
[0166] According to the imaging device 200 described above, use of the solid-state imaging device 10 having a reduced thickness and with a size reduction can achieve reduction in size and weight of the imaging device 200. In addition, the higher integration can be improved, thereby allowing a captured image with a higher image quality to be obtained.
[0167] Besides, the above description of each embodiment is an example of the present disclosure, and the present disclosure is not limited to the above embodiments. Therefore, it goes without saying that various modifications can be made so as to implement an embodiment other than each of the above-described embodiments depending on the design and the like without departing from the technical idea according to the present disclosure. Further, the effects described in the present disclosure are merely illustrative and not restrictive, and other effects may also be achieved.
[0168] In addition, the present technique can also adopt the following configurations.
(1)
[0169] A solid-state imaging device including: [0170] a first semiconductor chip including photodiodes; [0171] a second semiconductor chip including a signal processing circuit from the photodiodes and which is stacked on the first semiconductor chip; [0172] a first insulating film which is stacked on a second surface of the second semiconductor chip that is opposite to a first surface thereof having the first semiconductor chip stacked thereon and which includes oxygen; and [0173] a second insulating film stacked on the first insulating film and including oxygen.
(2)
[0174] The solid-state imaging device according to (1) above, in which [0175] the second insulating film includes a High-k dielectric having an oxygen surface density different from the first insulating film.
(3)
[0176] The solid-state imaging device according to (1) above or (2) above, in which [0177] the second insulating film stacked on the first insulating film includes a negative insulating film or a positive insulating film.
(4)
[0178] The solid-state imaging device according to any one of (1) above to (3) above, in which [0179] a third insulating film including a High-k dielectric is stacked on the second insulating film.
(5)
[0180] The solid-state imaging device according to any one of (1) above to (4) above, in which [0181] the second insulating film includes hafnium oxide (HfO.sub.2), aluminum oxide (Al.sub.2O.sub.3), zirconium oxide (ZrO.sub.2), tantalum pentoxide (Ta.sub.2O.sub.5), titanium oxide (TiO.sub.2), lanthanum oxide (La.sub.2O.sub.3), or yttrium oxide (Y.sub.2O.sub.3).
(6)
[0182] The solid-state imaging device according to any one of (1) above to (5) above, in which [0183] the second insulating film is stacked on a buried oxide film layer.
(7)
[0184] The solid-state imaging device according to any one of (1) above to (6) above, including: [0185] a third semiconductor chip having a semiconductor active element and in which the first insulating film and the second insulating film are stacked, in the first semiconductor chip or the second semiconductor chip.
(8)
[0186] The solid-state imaging device according to any one of (1) above to (7) above, in which [0187] two or more semiconductor chips are stacked on the first semiconductor chip.
(9)
[0188] A solid-state imaging device including: [0189] a semiconductor chip including photodiodes; [0190] a first insulating film stacked on an upper surface of the photodiodes on a light incidence surface side of the semiconductor chip and including oxygen; and [0191] a negative or a positive second insulating film stacked on the first insulating film and including oxygen.
(10)
[0192] A semiconductor chip including: [0193] a substrate having a polished surface; [0194] a first insulating film formed on the polished surface and including oxygen; [0195] a second insulating film stacked on the first insulating film and including oxygen; and [0196] a semiconductor active element.
(11)
[0197] The semiconductor chip according to (10) above, in which [0198] a second semiconductor chip is bonded to a surface that is opposite to the polished surface.
(12)
[0199] Electronic equipment including: [0200] a solid-state imaging device including [0201] a first semiconductor chip including photodiodes, [0202] a second semiconductor chip including a signal processing circuit from the photodiodes and which is stacked on the first semiconductor chip, [0203] a first insulating film which is stacked on a second surface of the second semiconductor chip that is opposite to a first surface thereof having the first semiconductor chip stacked thereon and which includes oxygen, and [0204] a second insulating film stacked on the first insulating film and including oxygen; or [0205] a semiconductor chip including [0206] a polished surface, [0207] a first insulating film stacked on the polished surface and including oxygen, [0208] a second insulating film stacked on the first insulating film and including oxygen, and [0209] a semiconductor active element.
REFERENCE SIGNS LIST
[0210] 10: Solid-state imaging device [0211] 101: CIS chip [0212] 102: Logic chip [0213] 103: Support substrate [0214] 104: Multilayer wiring layer [0215] 105: Silicon substrate [0216] 106: Monolithic chip [0217] 107: Solder ball [0218] 108: Buried oxide film (BOX layer) [0219] 109: Insulating film [0220] 111: On-chip lens [0221] 112: Color filter [0222] 113: Photodiode [0223] 114: Wiring layer [0224] 115: Pad [0225] 116: Photodiode formation layer [0226] 121: Pad [0227] 122: Wire [0228] 123: Transistor [0229] 125: Via [0230] 131: Oxide film [0231] 132: (Negative) charged film [0232] 133: (Positive) charged film [0233] 151: P well [0234] 152: N well [0235] 153: N+ diffusion layer [0236] 154: P+ diffusion layer [0237] 156: Gate [0238] 160: Bonding surface [0239] 161: Depletion layer [0240] 162: Defect [0241] 163: Hole [0242] 164: Electron [0243] 165: Internal electric field [0244] 166: Dipole [0245] 200: Imaging device [0246] 411: TSV