JP2010141041A - Mask, semiconductor device and manufacturing method of the same, solid-state image pickup device and manufacturing method of the same, and electronic information equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To greatly reduce processes. <P>SOLUTION: A reducing process of level difference of metal wherein, using a photo resist film whose film thickness is gradually varied by reticle wherein transmissivity of ultraviolet rays is selectively varied, as a mask, a metal layer 14 on an inter-layer insulating film 13 is removed to the middle in the thickness direction in an OB region 3, a wiring and electrode pad forming process wherein, in a peripheral circuit region 4 and a pad part region 5, the metal layer 14 on the inter-layer insulating film 13 is patterned to form the outline of a wiring 14A and an electrode pad 14B, and an electrode pad forming process wherein a surface barrier layer 14a of the electrode pad 14B is removed to expose the surface of the metal layer 14 in the pad part region 5, are executed simultaneously. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semiconductor device in which a mask for patterning using a resist film and a metal wiring on an interlayer insulating film are processed, and an external connection pad mainly composed of metal, for example, aluminum is formed connected to the metal wiring. And a manufacturing method thereof, a solid-state imaging device as a specific example of the semiconductor device and the manufacturing method thereof, a manufacturing method thereof, and the solid-state imaging device used as an image input device in an imaging unit such as a digital video camera and a digital still camera The present invention relates to an electronic information device such as a digital camera, an image input camera such as an in-vehicle camera and a surveillance camera, a scanner device, a facsimile device, a television phone device, and a camera-equipped mobile phone device.

  As a method for manufacturing this type of conventional semiconductor device, for example, in a conventional solid-state imaging device using a CCD (Charge Coupled Device), a metal is formed at the boundary between the effective pixel region at the center of the chip and the OB region at the periphery. Since a large step is generated by the wiring, a metal step reducing process is performed to remove the metal wiring partway in the film thickness direction. This is because, in the vicinity of the boundary between the effective pixel region in the central portion of the semiconductor chip and the OB region in the peripheral portion, a color filter in the subsequent on-chip layer formation, and a color filter or This is because the on-chip lens is tilted by being affected by the metal step, and its film thickness and shape are formed unevenly.

  As a result, in the peripheral portion of the effective pixel region, the light incident / condensed from the on-chip lens cannot be properly incident on the photoelectric conversion unit (photodiode unit) through the opening of the light shielding film, and the film thickness of the color filter Variations in color characteristics due to anomalies cause frame-like sensitivity unevenness (sensitivity nonuniformity) and color unevenness (color nonuniformity), and imaging failure may occur depending on the degree.

  In order to prevent this, as described above, the metal step portion near the boundary between the effective pixel region and the surrounding OB portion region is reduced, thereby improving sensitivity unevenness and color unevenness to improve image quality. This is very important.

  Conventionally, in metal wiring processing, electrode pad processing, and metal step reduction processing, etching is performed using a mask in each step.

  As an example of this metal step reduction processing, Patent Document 1 proposes that only the aluminum wiring in the peripheral circuit region is etched to reduce the step.

Next, as another example of this metal step reduction processing, Patent Document 2 proposes to continuously form a lens curved surface on the surface of a microlens array by using a continuous three-dimensional gray scale mask. Yes.
JP 2002-76322 A JP 2004-12940 A

  In the conventional solid-state imaging device, in order to improve the frame-shaped sensitivity unevenness and color unevenness around the effective pixel region, after performing metal wiring processing and electrode pad processing, metal level difference reduction processing is performed. These metal wiring processing, electrode pad processing, and metal step reduction processing are performed three times in separate steps, and there is a problem that production efficiency is poor.

  The present invention solves the above-mentioned conventional problems, and a mask for simultaneously processing three steps of metal wiring processing, electrode pad processing and metal step reduction processing by one photoetching process, and using this mask greatly Semiconductor device manufacturing method with good production efficiency, capable of reducing various processes, semiconductor device manufactured thereby, solid-state imaging device as a specific example of such a semiconductor device and its manufacturing method, and its manufacturing method, An object of the present invention is to provide an electronic information device such as a mobile phone device with a camera using the solid-state imaging device as an image input device in an imaging unit.

  In the mask of the present invention, the film thickness of the resist film is changed stepwise by a reticle with selectively changing the transmittance of ultraviolet rays, thereby achieving the above object.

  Preferably, the mask of the present invention is for forming a layer into a predetermined shape by etching the layer using a resist film.

  Further preferably, the mask is made by the transmittance of the ultraviolet rays of the reticle so as to have a resist film thickness required for processing each of the metal step reduction region, the metal wiring formation region and the electrode pad formation region in the mask of the present invention.

  A method of manufacturing a semiconductor device of the present invention includes a wiring / electrode pad forming step of patterning a metal layer on an interlayer insulating film using the mask of the present invention to form a wiring and an electrode pad, and a surface of the electrode pad The electrode pad forming step of removing the barrier layer and exposing the surface of the metal layer is performed at the same time, thereby achieving the above object.

  Preferably, in the method for manufacturing a semiconductor device according to the present invention, in addition to the wiring formation step and the electrode pad formation step, the metal layer on the interlayer insulating film is used in the thickness direction, using the mask according to the present invention. At the same time, the metal step reduction process is removed.

  Further preferably, in the method of manufacturing a semiconductor device according to the present invention, the thickness of the mask is such that the thickness of the resist film is the thickest in the region where the wiring formation step is performed, and the pad region where the electrode pad formation step is performed. Then, the film thickness of the resist film is set to the next largest film thickness.

  Still preferably, in a method of manufacturing a semiconductor device according to the present invention, the thickness of the mask is set to the smallest thickness in the region where the metal step reduction process is performed.

  The semiconductor device of the present invention is obtained by forming at least the metal wiring and the electrode pad among the metal wiring, the electrode pad, and the metal step reduction structure by the method for manufacturing a semiconductor device of the present invention. This achieves the above object.

  The method for manufacturing a solid-state imaging device according to the present invention includes a central effective pixel region provided with a plurality of light receiving units that photoelectrically convert incident light from a subject to generate signal charges, and a periphery of the effective pixel region. Manufacture of a solid-state imaging device having a provided optical black region, a peripheral circuit region further provided on the peripheral side of the optical black region, and a pad portion region for external wiring connection on the outer peripheral side of the peripheral circuit region In the method, using the mask of the present invention, a metal step reduction process for removing the metal black on the interlayer insulating film in the optical black region to the middle in the thickness direction, and the peripheral circuit region and the pad portion region A wiring / electrode pad forming step of patterning the metal layer on the interlayer insulating film to form a wiring and an electrode pad; and removing the surface barrier layer of the electrode pad in the pad portion region to expose the surface of the metal layer And it performs an electrode pad forming step simultaneously, the objects can be achieved.

  Preferably, the thickness of the mask in the method for manufacturing a solid-state imaging device of the present invention is such that the thickness of the resist film is the thickest in the peripheral circuit region, and the resist in the pad region of the electrode pad portion region. The film thickness is set to the next largest film thickness, and the film thickness of the resist film is set to the smallest film thickness in the optical black region.

  Further preferably, in the effective pixel region in the method for manufacturing a solid-state imaging device of the present invention, the thickness of the mask is set to “0”, and the metal layer is removed by etching.

  Further preferably, in the method for manufacturing a solid-state imaging device according to the present invention, the metal layer is etched and removed halfway in the thickness direction with the next thickest film thickness and the thinnest film thickness after the resist film.

  Further preferably, in the method for manufacturing a solid-state imaging device of the present invention, the film thickness produced by the transmittance of the ultraviolet rays of the reticle, which becomes a resist film thickness required for processing of metal step reduction, metal wiring formation and electrode pad formation. Etching is performed using the stepwise different resist films as masks to form the metal step reduction structure, the metal wiring, and the electrode pads.

  The solid-state imaging device of the present invention is the one in which the metal wiring and the electrode pad are formed and the metal level difference is reduced by the manufacturing method of the solid-state imaging device of the present invention. Is achieved.

  Preferably, the solid-state imaging device of the present invention is a CCD solid-state imaging device or a CMOS solid-state imaging device.

  The electronic information device of the present invention uses the solid-state imaging device of the present invention as an image input device in an imaging unit, and thereby achieves the above object.

  With the above configuration, the operation of the present invention will be described below.

  In the method of manufacturing a semiconductor device according to the present invention, the metal layer on the interlayer insulating film is patterned using a mask in which the thickness of the resist film is changed stepwise by a reticle whose ultraviolet transmittance is selectively changed. Then, the wiring / electrode pad forming step for forming the outer shape of the wiring and the electrode pad and the electrode pad forming step for removing the surface barrier layer of the electrode pad and exposing the metal layer surface are simultaneously performed.

  In the method for manufacturing a solid-state imaging device according to the present invention, a mask in which the film thickness of a resist film is changed stepwise by a reticle with selectively changing the transmittance of ultraviolet rays is used in an optical black region. A metal step reduction process that removes the metal layer on the insulating film halfway in the thickness direction, and wiring that forms the outer shape of the wiring and electrode pads by patterning the metal layer on the interlayer insulating film in the peripheral circuit area and pad area The electrode pad forming step and the electrode pad forming step of removing the surface barrier layer of the pad portion in the pad portion region and exposing the metal layer surface are simultaneously performed.

  As a result, by using a reticle whose ultraviolet transmittance is changed so as to have a plurality of resist thicknesses, a resist film having different thicknesses is formed, and this resist film is used as a mask to form a metal wiring. It is possible to simultaneously process the three processes of processing, electrode pad processing, and metal level difference reduction processing by one etching process, so that the process can be greatly reduced and the production efficiency is improved.

  As described above, according to the present invention, this resist film is formed by forming resist films having different thicknesses using a reticle whose ultraviolet transmittance is changed so as to have a plurality of predetermined resist film thicknesses. Using this as a mask, the three processes of metal wiring processing, electrode pad processing, and metal level difference reduction processing can be processed at the same time by one etching process, which can greatly reduce the process and improve the production efficiency. can do.

  Hereinafter, when applied to a solid-state imaging device and a manufacturing method thereof as Embodiment 1 of the semiconductor device and the manufacturing method thereof of the present invention, for example, a camera-equipped mobile phone device using the solid-state imaging device as an image input device in an imaging unit Embodiment 2 of the electronic information device will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a plan view showing a schematic chip configuration of a solid-state imaging device according to Embodiment 1 of the present invention.

  In FIG. 1, a solid-state imaging device 1 according to Embodiment 1 includes a central effective pixel region 2 having a plurality of matrix light receiving portions that photoelectrically convert incident light from a subject to generate signal charges, and this effective pixel region 2. An OB area 3 that is an optical black area (optical black portion) provided around the pixel area 2 and a peripheral circuit such as a driver that controls signal transfer and signal reading provided further on the peripheral side of the OB area 3 The region 4 and the outermost external pad connecting pad region 5 on the outer peripheral side of the peripheral circuit region 4 are provided.

  FIG. 2 is a diagram showing a characteristic curve (photosensitive curve) of a positive photoresist film. The vertical axis represents the photoresist film thickness, and the horizontal axis represents the ultraviolet transmittance of the reticle.

  In FIG. 2, instead of using a gray scale mask for forming a continuous curved surface as in Patent Document 2, the film thickness is changed for each region using a reticle in which a plurality of ultraviolet transmittances are selectively changed. Different photoresist films are patterned. Thus, by changing the reticle transmittance stepwise, the thickness of the photoresist film can be changed in accordance with the transmittance pattern. As this photoresist film, a normal photoresist film is used. Usually, a metal layer or the like is formed in a predetermined shape by the presence or absence (patterning) of the photoresist film, but here, the underlying metal layer or the like is completely etched. In addition to the thickest film thickness of the photoresist film that does not decrease, one or more types of metal layers can be etched and removed halfway in the film thickness direction using the intermediate film thickness of the photoresist film.

  FIG. 3 is a diagram showing a resist film thickness required for metal step reduction processing, metal wiring processing, and electrode pad processing in the solid-state imaging device 1 of FIG. In FIG. 3, the resist film thicknesses h1 to h3 may be set within the range of the width of the two-dot chain line indicated by the arrow. The resist film thickness increases toward the right side of the horizontal axis.

  3, in the solid-state imaging device 1 of FIG. 1, the metal film is left as the wiring portion in the metal wiring processing, so that the thickness of the photoresist film is h1, and in the electrode pad processing, only the uppermost barrier layer of the metal wiring is used. In order to reduce the thickness of the photoresist film, the thickness of the photoresist film is set to a thickness h2 smaller than the thickness h1, and in the metal step reduction process, the photoresist film is reduced to the middle of the barrier layer and the metal wiring. Is set to a thickness h3 that is thinner than the thickness h2. In this case, the film thicknesses h1 to h3 of the photoresist film satisfy h1> h2> h3. The film thickness h1 of the photoresist film is such that the underlying metal film is not etched. Thus, the film thickness h1 of the photoresist film is such that the underlying metal film is not etched, and the underlying metal film remains for the entire thickness. Since the film thickness h3 of the photoresist film is thinner than the film thickness h2, the remaining film thickness of the metal layer in the metal step reduction process is thinner.

  FIG. 4 is a longitudinal sectional view of the solid-state imaging device of FIG. 1 before and after etching of the metal step reduction processing portion, the metal wiring processing portion, and the electrode pad processing portion.

  4, each effective pixel portion 2 of the solid-state imaging device 1 of FIG. 1 is provided with a light receiving portion (photodiode 15) that photoelectrically converts incident light as a light receiving device to generate a signal charge. A charge transfer portion for transferring the signal charge from the photodiode 15 and a gate electrode 11 (polysilicon film) as a charge transfer electrode for controlling the charge transfer are disposed on the charge transfer portion. . A light shielding film 12 is formed on the gate electrode 11 to prevent incident light from being reflected by the gate electrode 11 and generating noise.

  Further, above the photodiode 15, an RGB color filter formed in a subsequent process and an optical condensing microlens thereabove through the interlayer insulating film 13 above the opening 12 a of the light shielding film 12. Will be placed.

  Here, a case will be described in which the metal level difference reducing process, the metal wiring process and the electrode pad process are simultaneously performed using one photoresist film as a mask.

  Obtain the UV transmittance of the reticle so that the resist film thickness required for each process is obtained, and use the UV transmittance of the reticle to obtain the resist film thickness required for each processing of metal step reduction, metal wiring formation and electrode pad formation. Etching is performed using the formed photoresist films with different thicknesses as a mask, and in addition to the metal layer 14C having the thickness reduction structure of the metal layer 14 in the OB region 3, the metal wiring 14A and the metal wiring pad portion Each desired shape of 14B is formed.

  As a result, the metal layer 14 provided on the interlayer insulating film 13 in the semiconductor integrated circuit of the peripheral circuit section 4 is processed by wiring (for example, metal (Ti / TiN / Al—Cu / TiN lamination)) to form the metal wiring 14A and the metal wiring. The outer shape of the pad portion 14B is formed, the surface barrier layer 14a of the metal layer 14 is removed to complete the metal wiring pad portion 14B, the removal of the metal layer 14 in the effective pixel region 2 in the solid-state imaging device, A metal layer 14C having a reduced thickness is formed in the surrounding OB region 3. Reference numeral 16 denotes an element isolation film.

  As described above, according to the first embodiment, the interlayer insulating film 13 is formed in the OB region 3 by using, as a mask, the photoresist film whose thickness is changed stepwise by the reticle whose ultraviolet transmittance is selectively changed. A metal step reduction process for removing the upper metal layer 14 partway in the thickness direction, and patterning the metal layer 14 on the interlayer insulating film 13 in the peripheral circuit region 4 and the pad portion region 5 to form the outer shape of the wiring 14A and the electrode pad 14B. The wiring / electrode pad forming step for forming the electrode pad and the electrode pad forming step for removing the surface barrier layer 14a of the electrode pad 14B in the pad region 5 to expose the surface of the metal layer 14 are performed simultaneously. In addition, 14b is a back surface barrier layer.

  In this way, by using a reticle whose ultraviolet transmittance is changed so as to have a plurality of predetermined resist film thicknesses, a photoresist film having different film thicknesses is formed, and this photoresist film is used as a mask. , Metal wiring processing, electrode pad processing and metal step reduction processing can be processed at the same time by one etching process, so that the process can be greatly reduced and the production efficiency is improved. Therefore, the frame-shaped sensitivity unevenness and color unevenness can be improved.

  In addition, the metal layer 14 in the OB region is partially removed from the film thickness, and the boundary portion of the two metal etching processes for patterning the metal layer 14 and wiring is overlapped, and a recess is formed in the overlap portion. Since the conventional inconvenience can be solved by one metal etching, there is no need for alignment and no concave portion is formed in the overlap portion. Since such a concave portion does not occur at the boundary portion, subsequent RGB color filters and microlenses can be formed with high accuracy.

  In the first embodiment, the central effective pixel region 2 provided with a plurality of light receiving units that photoelectrically convert incident light from a subject to generate signal charges, and the effective pixel region 2 are provided around the effective pixel region 2. In the manufacturing method of the solid-state imaging device 1 including the OB region 3, the peripheral circuit region 4 provided on the further peripheral side of the OB region 3, and the pad portion region 5 for external wiring connection on the outer peripheral side of the peripheral circuit region 4. The thickness direction of the metal layer 14 on the interlayer insulating film 13 in the OB region 3 using as a mask a photoresist film whose thickness is changed stepwise by a reticle whose ultraviolet transmittance is selectively changed A metal step reduction process that removes halfway, and a wiring that forms the outer shape of the wiring 14A and the electrode pad 14B by patterning the metal layer 14 on the interlayer insulating film 13 in the peripheral circuit region 4 and the pad portion region 5 The case where the electrode pad forming step and the electrode pad forming step of removing the surface barrier layer 14a of the electrode pad 14B on the interlayer insulating film 13 and exposing the surface of the metal layer in the pad region are simultaneously described has been described. Not limited to this, the method for manufacturing a solid-state imaging device may be generalized to be a method for manufacturing a semiconductor device (semiconductor integrated circuit).

In this method of manufacturing a semiconductor device (semiconductor integrated circuit), a photoresist film whose thickness is changed stepwise by a reticle with selectively changing the transmittance of ultraviolet rays is used as a mask on the interlayer insulating film 13. The metal layer 14 is patterned to form the outer shape of the metal wiring 14A and the electrode pad 14B, and the surface barrier layer 14a of the electrode pad 14B on the interlayer insulating film 13 is removed to remove the metal layer 14 What is necessary is just to perform simultaneously with the electrode pad formation process which exposes the surface. In addition to these wiring formation step and electrode pad formation step, a metal step reduction step for removing the metal layer 14 on the interlayer insulating film 13 in the thickness direction is performed simultaneously in order to perform precise film formation in a later step. You may make it perform. In this case, the film thickness of the photoresist film is such that the film thickness of the resist film is the thickest in the area where the wiring formation process is performed, and the film thickness of the resist film is the next largest in the pad area where the electrode pad formation process is performed. It can be. In addition, the photoresist film can be made the thinnest in the region where the metal step reduction process is performed.
(Embodiment 2)
FIG. 5 is a block diagram illustrating a schematic configuration example of an electronic information device using, as an imaging unit, a solid-state imaging device including the solid-state imaging device 1 according to the first embodiment of the present invention as the second embodiment of the present invention.

  In FIG. 5, an electronic information device 90 according to the second embodiment includes a solid-state imaging device 91 that obtains a color image signal by performing various signal processing on the imaging signal from the solid-state imaging device 1 according to the first embodiment, and the solid-state imaging device 91. A memory unit 92 such as a recording medium that can record data after a predetermined signal processing for recording a color image signal from the recording medium, and a liquid crystal after a predetermined signal processing for display of the color image signal from the solid-state imaging device 91 Display means 93 such as a liquid crystal display device which can be displayed on a display screen such as a display screen, and a transmission / reception device which can perform communication processing after performing predetermined signal processing for color image signals from the solid-state imaging device 91 for communication Communication means 94 such as a printer and the like, and a color image signal from the solid-state image pickup device 91 and an image output such as a printer that can perform print processing after performing predetermined print signal processing for printing. And a means 95. The electronic information device 90 is not limited to this, and in addition to the solid-state imaging device 91, at least one of a memory unit 92, a display unit 93, a communication unit 94, and an image output unit 95 such as a printer. You may have.

  As described above, the electronic information device 90 includes, for example, a digital camera such as a digital video camera and a digital still camera, an in-vehicle camera such as a surveillance camera, a door phone camera, and an in-vehicle rear surveillance camera, and a video phone camera. An electronic device having an image input device such as an image input camera, a scanner device, a facsimile device, a camera-equipped mobile phone device, and a portable terminal device (PDA) is conceivable.

  Therefore, according to the second embodiment, on the basis of the color image signal from the solid-state image pickup unit 91, it is displayed on the display screen, or is printed out by the image output unit 95 on the paper. (Printing), communicating this as communication data in a wired or wireless manner, performing a predetermined data compression process in the memory unit 92 and storing it in a good manner, or performing various data processings satisfactorily Can do.

  In the first embodiment, the manufacturing method of the CCD type solid-state imaging device 1 has been described. However, the present invention is not limited to this, and the main point is a CMOS type in which a metal step reduction processing step, a metal wiring processing step, and an electrode pad processing step are performed simultaneously. The manufacturing method of a solid-state image sensor may be sufficient.

  In each pixel portion of the CMOS solid-state image sensor, a light receiving portion (photodiode) as a photoelectric conversion portion is formed as a surface layer of the semiconductor substrate. A charge transfer portion of a charge transfer transistor for transferring signal charges to the floating diffusion portion FD is provided adjacent to the photodiode. On this charge transfer portion, a gate electrode as an extraction electrode is provided via a gate insulating film. Further, the signal charge transferred to the floating diffusion portion FD is converted into a voltage for each photodiode, amplified according to the converted voltage, and read out as an imaging signal for each pixel portion. .

  As mentioned above, although this invention was illustrated using preferable Embodiment 1, 2 of this invention, this invention should not be limited and limited to this Embodiment 1,2. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range based on the description of the present invention and the common general technical knowledge from the description of the specific preferred embodiments 1 and 2 of the present invention. Patents, patent applications, and documents cited herein should be incorporated by reference in their entirety, as if the contents themselves were specifically described herein. Understood.

  The present invention relates to a semiconductor device in which a metal wiring on an insulating film is processed and connected to the metal wiring, and an external connection pad mainly composed of metal, for example, aluminum, and a method for manufacturing the semiconductor device. Solid-state imaging device as a specific example of method and manufacturing method thereof, digital camera such as digital video camera and digital still camera, and image input camera such as surveillance camera using this solid-state imaging device as image input device in imaging unit In the field of electronic information equipment such as a scanner device, a facsimile device, a television phone device, a camera-equipped mobile phone device, etc., using a reticle mask that changes the transmittance of ultraviolet rays so as to have a plurality of predetermined resist film thicknesses, This photoresist is formed by forming photoresist films with different thicknesses. Using the copper film as a mask, the metal wiring processing, electrode pad processing, and metal step reduction processing can be processed at the same time by one photo-etching process, and the process can be greatly reduced, resulting in good production efficiency. Can be.

It is a top view which shows the schematic chip structure of the solid-state image sensor which concerns on Embodiment 1 of this invention. It is a figure which shows the characteristic curve (photosensitive curve) of a positive type photoresist film. The vertical axis represents the thickness of the photoresist film, and the horizontal axis represents the ultraviolet transmittance. In the solid-state image sensor 1 of FIG. 1, it is a figure which shows the resist film thickness required for a metal level | step difference reduction process, a metal wiring process, and an electrode pad process. FIG. 2 is a longitudinal sectional view before and after etching of a metal level difference reduction processing portion, a metal wiring processing portion, and an electrode pad processing portion of the solid-state imaging device of FIG. 1. It is a block diagram which shows the schematic structural example of the electronic information apparatus which used the solid-state imaging device containing the solid-state image sensor 1 of Embodiment 1 of this invention for Embodiment 2 of this invention for the imaging part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid-state image sensor 2 Effective pixel area | region 3 OB area | region 4 Peripheral circuit area | region 5 Pad part area | region h1 Film thickness of the photoresist film in metal wiring processing h2 Photoresist film thickness in electrode pad processing h3 In metal level | step difference reduction processing Film thickness of photoresist film 11 Gate electrode 12 Light shielding film 12a Opening 13 Interlayer insulating film 14 Metal layer 14A Metal wiring 14a Barrier layer 14B Metal wiring pad part 14C Metal layer with reduced film thickness 90 Electronic information equipment 91 Solid-state imaging device 92 Memory Unit 93 Display means 94 Communication means 95 Image output means

Claims (16)

  A mask in which the resist film thickness is changed stepwise by a reticle that selectively changes the transmittance of ultraviolet rays.   The mask according to claim 1, wherein the layer is etched into a predetermined shape using the resist film.   2. The mask according to claim 1, wherein the mask is formed by the transmittance of ultraviolet rays of the reticle so as to have a resist film thickness required for processing each of a metal step reduction region, a metal wiring formation region, and an electrode pad formation region. Using the mask according to any one of claims 1 to 3,
A wiring / electrode pad forming step of patterning a metal layer on the interlayer insulating film to form a wiring and an electrode pad;
A method of manufacturing a semiconductor device, comprising simultaneously performing an electrode pad forming step of removing a surface barrier layer of the electrode pad and exposing a metal layer surface. Using the mask according to any one of claims 1 to 3, in addition to the wiring formation step and the electrode pad formation step,
The method of manufacturing a semiconductor device according to claim 4, wherein a metal step reduction process for removing the metal layer on the interlayer insulating film halfway in the thickness direction is simultaneously performed.   The thickness of the mask is such that the thickness of the resist film is the thickest in the region where the wiring formation step is performed, and the thickness of the resist film is the next thickest in the pad region where the electrode pad formation step is performed. A method for manufacturing a semiconductor device according to claim 4.   The method of manufacturing a semiconductor device according to claim 6, wherein the thickness of the mask is such that the thickness of the resist film is the thinnest in a region where the metal step reduction process is performed.   A semiconductor device in which at least the metal wiring and the electrode pad are formed among the metal wiring, the electrode pad, and the metal step reduction structure by the method for manufacturing a semiconductor device according to claim 4. A central effective pixel region provided with a plurality of light receiving units that photoelectrically convert incident light from a subject to generate a signal charge, an optical black region provided around the effective pixel region, and the optical In a method for manufacturing a solid-state imaging device having a peripheral circuit region provided on the further peripheral side of the black region, and a pad portion region for external wiring connection on the outer peripheral side of the peripheral circuit region,
Using the mask according to any one of claims 1 to 3,
A metal step reduction step for removing the metal layer on the interlayer insulating film in the optical black region halfway in the thickness direction;
A wiring / electrode pad forming step of patterning a metal layer on the interlayer insulating film in the peripheral circuit region and the pad portion region to form a wiring and an electrode pad;
A method for manufacturing a solid-state imaging device, wherein an electrode pad forming step of removing a surface barrier layer of the electrode pad and exposing a metal layer surface in the pad portion region is performed simultaneously.   The mask is formed such that the thickness of the resist film is the thickest in the peripheral circuit region, and the resist film is the second thickest in the pad region of the electrode pad region. The method for manufacturing a solid-state imaging device according to claim 9, wherein the resist film is formed to be the thinnest in the target black region.   10. The method of manufacturing a solid-state imaging device according to claim 9, wherein in the effective pixel region, the thickness of the mask is set to “0” and the metal layer is removed by etching.   10. The method of manufacturing a solid-state imaging device according to claim 9, wherein the metal layer is etched and removed halfway in the thickness direction by the next thickest film thickness and the thinnest film thickness after the resist film.   Etching is performed using a resist film with a stepwise difference in film thickness created by the UV transmittance of the reticle, which becomes the resist film thickness required for each processing of metal step reduction, metal wiring formation and electrode pad formation, The method for manufacturing a solid-state imaging device according to claim 9 or 10, wherein each shape of the metal step reduction structure, the metal wiring, and the electrode pad is formed.   The solid-state image sensor by which the metal wiring and the electrode pad were formed by the manufacturing method of the solid-state image sensor in any one of Claims 9-13, and the metal level | step difference reduction was performed.   The solid-state imaging device according to claim 14, which is a CCD solid-state imaging device or a CMOS-type solid-state imaging device.   An electronic information device using the solid-state imaging device according to claim 14 as an image input device in an imaging unit.