JP2009259877A - Solid-state image pickup apparatus and method for manufacturing solid-state image pickup apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress deterioration in image quality caused by the generation of the unevenness of an output image. <P>SOLUTION: A light-shielding film is formed so as to be insulated and divided into a metal light-shielding film 211 working also as a shunt wiring formed on the upper portion of a transfer electrode 209 and a light-shielding film 215 formed on at least the side of the transfer electrode 209. By this, since a distance between the metal light-shielding film 211 working also as a shunt wiring and a transfer channel region can be kept while maintaining high-speed transfer, the formation of a channel by the light-shielding film 211 can be suppressed, and, deterioration in image quality caused by the generation of the unevenness of the output image can be suppressed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a solid-state imaging device using a solid-state imaging device such as a CCD as an imaging device and a method for manufacturing the same.

  A solid-state image pickup device represented by a CCD type solid-state image pickup device is widely used as an image pickup device of an image pickup device such as a digital still camera or a digital video camera, and the demand thereof is increasing. In recent years, with the progress of high-definition televisions, the demand for high-definition moving image support in imaging devices and the like has led to demands for faster transfer frequencies in solid-state imaging devices.

  A shunt wiring technique is known as a technique that enables high-speed transfer, that is, high-speed transfer. Here, the configuration of a conventional solid-state imaging device will be described with reference to FIGS. 17 and 18.

  FIG. 17 is a cross-sectional view showing a structure of a conventional solid-state imaging device, and is a cross-sectional view showing a schematic configuration in a pixel portion of a solid-state imaging device provided with a shunt wiring. FIG. 18 is a schematic plan view of a transfer electrode in a conventional solid-state imaging device, in which 307 and 308 are shunt wirings, 318 and 317 are shunt wiring and transfer gate electrode contacts, 301 is a first phase transfer gate electrode, Reference numeral 306 denotes a second phase transfer gate electrode, and reference numeral 305 denotes a third phase transfer gate electrode.

As shown in FIG. 17, the solid-state imaging device includes an n-type silicon substrate as the semiconductor substrate 101. A transfer electrode 109 made of a polycrystalline silicon film is formed on the semiconductor substrate 101 with an insulating film 108 interposed therebetween. The transfer electrode 109 constitutes a vertical charge transfer unit 114 together with a transfer channel 103 formed of an n-type well formed in a p-type well. The p-type well has an n-type photodiode 105 which is a light receiving unit that converts light into electric charges and accumulates electric charges. The charge accumulated in the photodiode 105 is read out to the transfer channel 103 by applying a read voltage to the transfer electrode 109 on the read channel 107. On the other hand, a high-concentration p-type region 104 is provided on the opposite side of the transfer channel 103 to the read channel 107, and even if a read voltage is applied to the transfer electrode 109, the charge accumulated in the opposite photodiode is transferred to the transfer channel 103. Inflow to 103 is prevented. The transfer electrode 109 is covered with an interlayer insulating film 110. On the interlayer insulating film 110, a metal light shielding film 111 is formed in a stripe shape along a column of pixels (pixel column) arranged in the vertical direction. Since the light shielding film 111 is electrically connected to the transfer electrode 109 by a contact 113 penetrating the interlayer insulating film 110, the resistance of the transfer electrode is reduced, and high-speed transfer is possible (see, for example, Patent Document 1). .
JP-A-4-279059

  In the conventional solid-state imaging device, at least three kinds of voltages are applied to the light shielding film 111 (transfer electrode 109). Specifically, the voltage VH (about 10 to 20 V) for causing the vertical charge transfer unit 114 to read out the charge, the voltage VM (about 0 V) for storing the charge in the vertical charge transfer unit, and the vertical charge The voltage VL (−5 V to −10 V) for forming a barrier in the transfer unit. A voltage VH (about 10 to 20 V) is applied to the transfer electrode 109 and the charge accumulated in the photodiode 105 is read out to the transfer channel 103. Then, the voltage VL and the voltage VM are applied to the transfer electrode, and the transfer channel 109 To transfer the charge.

  However, the same level of voltage is not applied to all the plurality of light shielding films 111 at the same time, and the level of the applied voltage differs between adjacent light shielding films 111. In addition, since the light shielding film 111 is provided for each pixel column in the vertical direction, the level of the voltage applied between the light shielding film 111 and the interface on the surface layer side of the semiconductor substrate 101 is the adjacent pixel column. Are different.

  For example, it is assumed that a voltage VH (about 10 to 20 V) for reading signal charges is applied to the light shielding film 307 in FIG. At that time, the read voltage VH (about 10 to 20 V) is supplied to the transfer electrode 301 via the contact 318. However, when the voltage VL (about −5 V to −10 V) is supplied to the adjacent transfer electrode 306 from the light shielding film 308 via the contact 317, the voltage VL (about −5 V to −10 V) is supplied. ) May be in a voltage VH (about 10 to 20 V) state, and the effective area of the surface channel region may change, causing output unevenness. This causes a problem that the image quality of the output image deteriorates.

  That is, in FIG. 17, when the read voltage VH is supplied to the light shielding film 111b when the transfer electrode 109b not intended to be read is at the voltage VL, the light shielding film 111b is formed in the surface channel region of the light shielding film 111b end (region X). Serves as a gate electrode to induce holes on the surfaces of the readout channel 107 and the high-concentration p-type region 104, and the area of the transfer channel 103b is effectively changed. Unevenness causes deterioration of image quality.

  An object of the present invention is to solve the above-described problems and suppress deterioration in image quality due to occurrence of unevenness in an output image.

  In order to achieve the above object, a solid-state imaging device according to the present invention includes a semiconductor substrate in which a light receiving region and a transfer region are formed, a first insulating film formed on the semiconductor substrate, and the semiconductor substrate. A transfer electrode formed on the transfer region via the first insulating film, a sidewall light-shielding film formed on a side surface of the transfer electrode, and formed on the entire surface including the transfer electrode and the sidewall light-shielding film A second light-insulating film, and a metal light-shielding film electrically connected to the transfer electrode and formed on the transfer electrode and the side-wall light-shielding film via the second insulating film. Features.

The sidewall light-shielding film contains tungsten.
The sidewall light shielding film is a tungsten silicide film.

  Further, the semiconductor substrate on which the light receiving region and the transfer region are formed, a first insulating film formed on the semiconductor substrate, and the first insulating film is formed on the transfer region of the semiconductor substrate via the first insulating film. A polycrystalline silicon film, a metal silicide film formed on and over the polycrystalline silicon film, a second insulating film formed on the entire surface including the metal silicide film, and the metal silicide film electrically And a metal light shielding film formed on the metal silicide film via the second insulating film, and a transfer electrode is formed by the polycrystalline silicon film and the metal silicide film. .

Further, the metal light shielding film contains tungsten.
The first insulating film is a laminated film of a silicon oxide film and a silicon nitride film.

  Furthermore, the method for manufacturing a solid-state imaging device is a method for manufacturing a solid-state imaging device in which a light receiving region and a transfer region are formed on a semiconductor substrate. When forming a transfer electrode and a light shielding film, a first insulation is formed on the substrate. A step of forming a film, a step of forming a polycrystalline silicon film in a stripe shape having a slit on the first insulating film, a step of depositing a silicon oxide film on the entire surface including the inside of the slit, and the light receiving region Selectively removing the polycrystalline silicon film above to form a transfer electrode made of the polycrystalline silicon film; forming a tungsten film over the entire surface; etching the tungsten film to form the transfer electrode; Forming a sidewall light-shielding film made of the tungsten film on a side surface; forming an interlayer insulating film on the entire surface; and forming an interlayer insulating film on the transfer electrode Forming a contact hole, characterized in that it comprises a step of forming a metal light-shielding film connected through the interlayer insulating film on the transfer electrode with said transfer electrode and electrically.

  Further, a method of manufacturing a solid-state imaging device in which a light receiving region and a transfer region are formed on a semiconductor substrate, and forming a first insulating film on the substrate when forming a transfer electrode and a light shielding film, A step of forming a polycrystalline silicon film in a stripe shape having a slit on the first insulating film; a step of depositing a silicon oxide film on the entire surface including the inside of the slit; and the polycrystalline silicon film on the light receiving region. A step of selectively removing and forming a transfer electrode made of the polycrystalline silicon film; a step of forming a tungsten film on the entire surface; and a step of siliciding at least the tungsten film on the side surface of the transfer electrode by heat treatment. Removing the remaining tungsten film to form a sidewall light-shielding film on the side surface of the transfer electrode, and a process for forming an interlayer insulating film on the entire surface. And forming a contact hole in the interlayer insulating film on the transfer electrode; and forming a metal light-shielding film electrically connected to the transfer electrode through the interlayer insulating film on the transfer electrode. It is characterized by providing.

  Further, a method of manufacturing a solid-state imaging device in which a light receiving region and a transfer region are formed on a semiconductor substrate, and forming a first insulating film on the substrate when forming a transfer electrode and a light shielding film, Forming a polycrystalline silicon film in a stripe shape while opening the light-receiving region on the first insulating film; depositing a tungsten film on the entire surface including the inside of the opening; and heat-treating the polycrystalline film A step of siliciding the tungsten film on the surface of the silicon film, a step of removing the remaining tungsten film to form a transfer electrode comprising the polycrystalline silicon film and the silicided tungsten film, and interlayer insulation over the entire surface Forming a film; forming a contact hole in the interlayer insulating film on the transfer electrode; and interlayer insulating on the transfer electrode Through, characterized in that it comprises a step of forming the transfer electrodes electrically connected to the metal light-shielding film.

  As described above, it is possible to suppress deterioration in image quality due to occurrence of unevenness in the output image.

  As described above, the light-shielding film is divided into a metal light-shielding film also serving as a shunt wiring formed on the transfer electrode and at least a light-shielding film formed on the side of the transfer electrode, so that high-speed transfer is achieved. Since the metal light-shielding film that also serves as the shunt wiring can maintain a distance from the transfer channel region while maintaining, the formation of the channel by the metal light-shielding film can be suppressed, and the deterioration of the image quality due to the occurrence of unevenness in the output image can be suppressed. it can.

(First embodiment)
Hereinafter, the structure of the solid-state imaging device according to the first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a cross-sectional view illustrating the structure of the solid-state imaging device according to the first embodiment, and FIG. 2 is a schematic plan view illustrating the configuration of the light shielding film of the solid-state imaging device according to the first embodiment.
As shown in FIG. 1, the solid-state imaging device includes an n-type silicon substrate as a semiconductor substrate 201. A transfer electrode 209 made of a polycrystalline silicon film having a thickness of 200 nm is formed on the semiconductor substrate 201 via an insulating film 208 made of, for example, a silicon oxide film having a thickness of 25 nm and a silicon nitride film having a thickness of 25 nm. . The transfer electrode 209 forms a vertical charge transfer unit 214 together with the transfer channel 203. Further, a first metal light-shielding film 215 having a width of 120 nm made of a refractory metal such as tungsten (hereinafter referred to as W) is directly formed on the side wall of the transfer electrode 209 by an etch back method or the like. The transfer electrode 209 and the light shielding film 215 are covered with an interlayer insulating film 210 made of a silicon oxide film or silicon nitride film having a thickness of about 150 nm, and a second refractory metal made of refractory metal such as tungsten having a thickness of 150 nm is formed thereon. A light shielding film 211 made of metal is formed in a stripe shape along a column of pixels (pixel column) arranged in the vertical direction. The light shielding film 211 is electrically connected to the transfer electrode 209 by a contact 213 penetrating the interlayer insulating film 210 and also serves as a shunt wiring.

  According to the present embodiment, the distance between the light-shielding film (shunt wiring) and the transfer channel region surface is the same as that of the insulating film on the transfer channel region surface (about 50 nm). The light shielding film is composed of two light shielding films, the light shielding film 215 is formed on the side wall of the transfer electrode 209, and the light shielding film 211 is used as a shunt wiring to ensure light shielding properties, and the second metal light shielding film 211 is formed on the surface of the transfer channel region. Is at least 350 nm, which corresponds to the sum of the thickness of the transfer electrode 209 of 200 nm and the thickness of the interlayer insulating film 210 formed on the upper surface thereof, so that a read voltage is applied to the second metal light-shielding film 211. However, the influence on the surface of the transfer channel region of a pixel that is not intended to be read out is effectively eliminated. Therefore, unevenness of the output image is eliminated and a high-quality image can be obtained.

FIG. 2 shows a modification of the present invention in which the W light-shielding film has a structure that covers the vertical isolation region of the photodiode. This structure is a structure in which the light shielding film 211 covers up to the vertical isolation region of the photodiode. Since the light shielding film 211 also serves as a shunt wiring and electrically insulates the adjacent shunt wiring, a leakage current is generated between the adjacent shunt wirings. It is necessary to provide a gap necessary for ensuring a withstand voltage. Accordingly, since the slit portion cannot be completely covered with the shunt wiring, smear may occur due to light transmitted through the gap. Therefore, it is necessary to provide a gap 400 having a width that minimizes the influence of leakage light on smear on the vertical isolation region of the photodiode. A smaller width of the gap can suppress the occurrence of smear, but it must be set to a width that does not cause leakage current or electrostatic breakdown due to a potential difference applied between the shunt wirings on both sides. When the potential difference is about 15 V, if the width is about 300 nm, the breakdown voltage does not become a problem, and smear can be suppressed to a practical level.
(First manufacturing method)
Next, a first manufacturing method of the solid-state imaging device shown in the present embodiment will be briefly described with reference to FIGS. 3 to 10 are schematic views showing the method of manufacturing the solid-state imaging device according to the first embodiment, in which the step of forming the diffusion layer in the silicon substrate is omitted and the step of forming the charge transfer electrode is shown. Here, FIGS. 3 (a), 5 (a), 6 (a), and 10 are schematic plan views, and FIGS. 3 (b), 4, 5 (b), 6 (b), and FIG. 7, FIG. 8 (a), and FIG. 9 (a) are schematic cross-sectional views in the vertical direction, which is the formation direction of the vertical CCD, and FIG. 6 (c), FIG. 8 (b), and FIG. It is a schematic sectional drawing of the horizontal direction to do.

  <Step 1> FIG. 3 shows the formation of a silicon oxide film 1101 and a silicon nitride film 1102 on a P-type well region 202 (see FIG. 1) of a semiconductor substrate 201 (see FIG. 1), which is an N-type silicon substrate. A plan view of a state in which an insulating film 208 (see FIG. 1) is formed by laminating the crystalline silicon film 1103 and a stripe pattern of polycrystalline silicon 1103 to be the transfer electrode 209 (see FIG. 1) is formed in the imaging region. It is (a) and sectional drawing (b). For example, the thickness of the silicon oxide film 1101 is 25 nm, the thickness of the silicon nitride film 1102 is 25 nm, and the thickness of the polycrystalline silicon film is 200 nm. Here, the width of the slit 1104 serving as the gap 400 (see FIG. 2) between the polycrystalline silicon layers 1103 is 110 nm.

<Step 2> Next, a silicon oxide film 1105 is deposited on the surface of the semiconductor substrate 201 (see FIG. 1) by a CVD method of 100 nm to completely fill the slit 1104 (FIG. 4).
<Step 3> Thereafter, the silicon oxide film 1105 other than the inside of the slit 1104 is removed by an etch-back method or a CMP method, and an opening 1106 is formed above the photodiode 205 using a resist by a photolithography technique (FIG. 5). ).

  <Step 4> The polycrystalline silicon film 1103 inside the opening 1106 is selectively removed by dry etching. At this time, for example, if etching is performed by a known anisotropic plasma etching technique using a mixed gas of HBr and oxygen (O 2), the etching rate ratio between the polycrystalline silicon film 1103 and the silicon oxide film 1105 is increased. This silicon oxide film 1105 can be preserved (FIG. 6). FIG. 6C is a horizontal sectional view of the opening. In particular, the amount of reduction in the height of the oxide film 1105 can be reduced around the opening 1106.

<Step 5> Thereafter, a W film 1108 having a thickness of 100 nm to be the first light-shielding film 215 (see FIG. 1) is formed by sputtering or CVD (FIG. 7).
<Step 6> Next, when the W film 1108 is etched by anisotropic etching to remove the W film 1108 on the polycrystalline silicon 1103, a sidewall-like W film 1109 can be formed around the opening 1106 (FIG. 6). 8). At this time, since the silicon oxide film 1105 remains at the end of the opening 1106, the polycrystalline silicon electrode film 1103 on both sides thereof is not short-circuited by the sidewall W film 1109. In addition, since the height of the silicon oxide film 1105 is reduced near the center of the opening 1106, the W film 1108 near the center in the opening is removed together with the W film 1109 on the gentle slope from the end. A significant decrease in the area of the opening can be ignored.

  In this step, the purpose is to remove the W film 1108 in the photodiode opening 1106. If the W film 1108 in the photodiode opening 1106 can be removed, the W film remains on the polycrystalline silicon 1103. There is no problem.

<Step 7> Next, an interlayer insulating film 1110 is formed on the surface of the semiconductor substrate 201 (see FIG. 1) (FIG. 9).
<Step 8> After that, a second light-shielding film 211 (also shown in FIG. 1) serving as a transfer electrode 209 (see FIG. 1) in a predetermined region of the interlayer insulating film 1110 and a shunt wiring deposited thereafter. And a selective etching process of W to be the second light-shielding film 211 (see FIG. 1), and the formation of a W film to be the second light-shielding film 211 (see FIG. 1). As a result, the main part of the solid-state imaging device of the present invention is formed (FIG. 10).

  In Step 6, when it is necessary to completely remove the silicon oxide film 1105 and the W film 1108 remaining in the opening 1106, the W film 1108 residue in the opening 1106 is removed by using a separate photolithography technique. By adding a process of removing by hydrogen oxide water or dry etching or a process of removing the silicon oxide film 1105 by hydrofluoric acid or dry etching, it can be easily realized because the base is a nitride film. At this time, the silicon nitride film 1102 can increase the selectivity with respect to the oxide film when the oxide film and W remaining on the silicon nitride film 110 are selectively removed. The oxide film can be removed.

Further, after this, the silicon nitride film 1102 is removed by etching, and an antireflection film is formed on the surface of the photodiode, whereby the sensitivity can be improved.
(Second manufacturing method)
The second manufacturing method will be described. The second manufacturing method is the same up to the step of forming the W film 1108 having a thickness of 100 nm to be the first light-shielding film 215 (see FIG. 1) shown in FIG. 7 in the first manufacturing method.

  <Step 9> Heat treatment is performed at a temperature of about 800 ° C. in which silicidation occurs in the state where the W film 1108 is formed. A tungsten silicide film is formed on the surface of the polycrystalline silicon 1103 by the heat treatment. Thereafter, if W that is not silicided is removed by hydrogen peroxide solution or the like, a silicide film can be formed as a light shielding film 215 (see FIG. 1) only around the polycrystalline silicon 1103.

  Here, a silicide film is formed on the side surface of the polycrystalline silicon 1103 in a sidewall shape, and a silicide film is also formed on the surface (upper surface). However, after depositing the polycrystalline silicon film 1103, before the pattern of the slit 1104 is formed by photolithography, or after the surface is flattened by embedding the insulating film in the slit 1104, the photo for forming the opening of the photodiode is formed. If an oxide film is formed on the upper surface of the polycrystalline silicon 1103 by a thermal oxidation method, a CVD method, or the like before the lithography process, the silicidation reaction on the upper surface of the polycrystalline silicon 1103 can be suppressed. A film is not formed, and a silicide film is formed only on the side surface.

  According to this method, the silicon oxide film 1105 remains in the center of the opening. However, if the selective ratio between the polycrystalline silicon and the silicon oxide film is reduced as an etching condition when forming the opening 1106 shown in FIG. There is little concern that the characteristics of the image sensor are substantially impaired. Thereafter, the subsequent steps for forming the interlayer insulating film 1110 are the same as those in the first manufacturing method.

(Second Embodiment)
Next, the structure of the solid-state imaging device according to the second embodiment of the present invention will be described with reference to FIG. FIG. 11 is a schematic cross-sectional view showing the structure of the solid-state imaging device according to the second embodiment. Since portions other than the charge transfer electrode are the same as those in the first embodiment, they are omitted from the drawing. Only the position is shown.

  As shown in FIG. 11, on a semiconductor substrate 201, for example, a transfer made of a polycrystalline silicon film having a thickness of 200 nm via an insulating film 208 made of a silicon oxide film having a thickness of 25 nm and a silicon nitride film having a thickness of 25 nm. An electrode 209 is formed. In the first embodiment, a first metal light-shielding film having a width of 120 nm made of a refractory metal such as tungsten is directly formed on the side wall of the transfer electrode 209 by an etch back method. In this embodiment, the transfer electrode 209 has a structure in which the periphery of the polycrystalline silicon 209C is covered with the metal silicide 209S, and the upper surface of the transfer electrode 209 includes the light-shielding film 211. . The transfer electrode 209 is covered with an interlayer insulating film 210 made of a silicon oxide film or silicon nitride film having a thickness of about 150 nm, and a light shielding made of a second metal made of a refractory metal such as tungsten having a thickness of 150 nm is formed thereon. The film 211 is formed in a stripe shape along a column of pixels (pixel column) arranged in the vertical direction. The light shielding film 211 is electrically connected to the transfer electrode 209 by a contact 213 penetrating the interlayer insulating film 210 and also serves as a shunt wiring.

  The structure of the solid-state imaging device of the present embodiment is that the transfer electrode has a W film on the side surface of the polycrystalline silicon in the first embodiment, whereas the surface of the polycrystalline silicon is silicided. It differs in that it is covered with a film.

  If the metal silicide used as the transfer electrode 209 is a refractory metal silicide such as cobalt silicide, titanium silicide, nickel silicide, etc., it can be easily manufactured using existing techniques.

  As described above, by covering the transfer electrode with the metal silicide, the resistance of the transfer electrode can be reduced, and the light shielding film 211 that also serves as the shunt wiring is formed with a sufficient distance from the surface of the transfer channel region. Even when a read voltage is applied to the metal light-shielding film 211, the influence on the surface of the transfer channel region of pixels that are not intended to be read is effectively eliminated, the output image is not uneven, and a high-quality image can be obtained.

(Third production method)
Hereinafter, a method for manufacturing the solid-state imaging device according to the second embodiment will be described with reference to FIGS.

12 to 16 are schematic views illustrating a method of manufacturing the solid-state imaging device according to the second embodiment.
First, as shown in FIG. 12, a polycrystalline silicon film 1103 is laminated on a silicon oxide film 1101 and a silicon nitride film 1102 formed on a semiconductor substrate 201 (see FIG. 11), which is an N-type silicon substrate, to form an insulating film. 208 (see FIG. 11) is formed, and a stripe pattern of polycrystalline silicon 1103 to be the transfer electrode 209 (see FIG. 11) and an opening of the photodiode portion are formed in the imaging region (FIG. 12 (a) plan view). And FIG. 12 (b) sectional view).

  Next, for example, when a W film 1201 having a thickness of 30 nm is formed on the entire surface of the semiconductor substrate by sputtering or CVD, and a heat treatment at 800 ° C. is performed, a tungsten silicide film is formed on the surface of the polycrystalline silicon (FIG. 13A is a light-shielding film formation region cross-sectional view, and FIG. 13B is a light-shielding film opening region cross-sectional view. Thereafter, for example, by supplying hydrogen peroxide water to the surface of the semiconductor substrate, the non-silicided W remaining in the photodiode opening and the slit is removed, and the tungsten silicide film formed on the surface of the polycrystalline silicon. Then, the transfer electrode 209 is formed (FIG. 14 (a) light-shielding film cross-sectional view, FIG. 14 (b) light-shielding film opening area cross-sectional view).

  Thereafter, an insulating film such as a silicon oxide film 1206 is formed on the surface of the transfer electrode 209 by a CVD method, and an opening serving as a contact with the shunt wiring is formed at a predetermined position of the transfer electrode 209 (FIG. 15A) FIG. 15B is a cross-sectional view of a film formation region, and FIG. The subsequent process of forming a W film serving as a light-shielding film also serving as the shunt wiring 1207 is the same as the manufacturing method of the first embodiment (FIG. 16 (a) light-shielding film forming region sectional view, FIG. 16 (b)). Light shielding film opening area sectional view).

  According to the third manufacturing method, even if the width of the slit portion is about 110 nm, which corresponds to the modification limit of the exposure technique using a KrF excimer laser, for example, the polycrystalline silicon undergoes volume expansion during silicidation and is about 60 nm. Since the slit width can be narrowed, the charge transfer efficiency can be easily improved.

  INDUSTRIAL APPLICABILITY The present invention can suppress deterioration in image quality due to occurrence of unevenness in an output image, and is useful for a solid-state imaging device using a solid-state imaging device such as a CCD as an imaging device, a manufacturing method thereof, and the like.

Sectional drawing which shows the structure of the solid-state imaging device in 1st Embodiment 1 is a schematic plan view showing a configuration of a light shielding film of a solid-state imaging device according to a first embodiment Schematic which shows the manufacturing method of the solid-state imaging device in 1st Embodiment. Schematic which shows the manufacturing method of the solid-state imaging device in 1st Embodiment. Schematic which shows the manufacturing method of the solid-state imaging device in 1st Embodiment. Schematic which shows the manufacturing method of the solid-state imaging device in 1st Embodiment. Schematic which shows the manufacturing method of the solid-state imaging device in 1st Embodiment. Schematic which shows the manufacturing method of the solid-state imaging device in 1st Embodiment. Schematic which shows the manufacturing method of the solid-state imaging device in 1st Embodiment. Schematic which shows the manufacturing method of the solid-state imaging device in 1st Embodiment. Schematic sectional view showing the structure of the solid-state imaging device in the second embodiment Schematic which shows the manufacturing method of the solid-state imaging device in 2nd Embodiment. Schematic which shows the manufacturing method of the solid-state imaging device in 2nd Embodiment. Schematic which shows the manufacturing method of the solid-state imaging device in 2nd Embodiment. Schematic which shows the manufacturing method of the solid-state imaging device in 2nd Embodiment. Schematic which shows the manufacturing method of the solid-state imaging device in 2nd Embodiment. Sectional drawing which shows the structure of the conventional solid-state imaging device Outline plan view of transfer electrode in conventional solid-state imaging device

Explanation of symbols

101 201 Semiconductor substrate 202 P type well region 103 103b 203 Transfer channel 104 P type region 105 205 Photo diode 107 Read channel 108 208 Insulating film 109 109b 209 Transfer electrode 110 210 Interlayer insulating film 111 111b 211 Light shielding film 113 213 Contact 114 214 214 Vertical Charge transfer portion 215 Second light shielding film 209C Polycrystalline silicon 209S Metal silicide 301 Transfer electrode 306 Transfer electrode 307 Light shielding film 308 Light shielding film 317 Contact 318 Contact 400 Gap 1101 Silicon oxide film 1102 Silicon nitride film 1103 Polycrystalline silicon 1104 Slit 1105 Silicon Oxide film 1106 Opening 1108 W film 1109 W film 1110 Interlayer insulating film 1201 W film 1206 Silicon Oxide film 1207 Shunt wiring

Claims (9)

A semiconductor substrate on which a light receiving region and a transfer region are formed;
A first insulating film formed on the semiconductor substrate;
A transfer electrode formed on the transfer region of the semiconductor substrate via the first insulating film;
A sidewall light-shielding film formed on a side surface of the transfer electrode;
A second insulating film formed on the entire surface including the transfer electrode and the sidewall light-shielding film;
A solid-state imaging device comprising: a metal light-shielding film electrically connected to the transfer electrode and formed on the transfer electrode and the sidewall light-shielding film via the second insulating film.   The solid-state imaging device according to claim 1, wherein the sidewall light-shielding film contains tungsten.   The solid-state imaging device according to claim 1, wherein the sidewall light-shielding film is a tungsten silicide film. A semiconductor substrate on which a light receiving region and a transfer region are formed;
A first insulating film formed on the semiconductor substrate;
A polycrystalline silicon film formed on the transfer region of the semiconductor substrate via the first insulating film;
A metal silicide film formed on the upper and side surfaces of the polycrystalline silicon film;
A second insulating film formed on the entire surface including the metal silicide film;
A metal light-shielding film electrically connected to the metal silicide film and formed on the metal silicide film via the second insulating film, and a transfer electrode formed of the polycrystalline silicon film and the metal silicide film A solid-state imaging device formed.   The solid-state imaging device according to claim 1, wherein the metal light-shielding film contains tungsten.   The solid-state imaging device according to claim 1, wherein the first insulating film is a laminated film of a silicon oxide film and a silicon nitride film. A method of manufacturing a solid-state imaging device in which a light receiving region and a transfer region are formed on a semiconductor substrate,
When forming the transfer electrode and the light shielding film,
Forming a first insulating film on the substrate;
Forming a polycrystalline silicon film in a stripe shape having slits on the first insulating film;
Depositing a silicon oxide film on the entire surface including the inside of the slit;
Selectively removing the polycrystalline silicon film on the light receiving region to form a transfer electrode made of the polycrystalline silicon film;
Forming a tungsten film on the entire surface;
Etching the tungsten film to form a sidewall light-shielding film made of the tungsten film on a side surface of the transfer electrode;
Forming an interlayer insulating film on the entire surface;
Forming a contact hole in the interlayer insulating film on the transfer electrode;
Forming a metal light-shielding film electrically connected to the transfer electrode via the interlayer insulating film on the transfer electrode. A method of manufacturing a solid-state imaging device in which a light receiving region and a transfer region are formed on a semiconductor substrate,
When forming the transfer electrode and the light shielding film,
Forming a first insulating film on the substrate;
Forming a polycrystalline silicon film in a stripe shape having slits on the first insulating film;
Depositing a silicon oxide film on the entire surface including the inside of the slit;
Selectively removing the polycrystalline silicon film on the light receiving region to form a transfer electrode made of the polycrystalline silicon film;
Forming a tungsten film on the entire surface;
Siliciding at least the tungsten film on the side surface of the transfer electrode by heat treatment;
Removing the remaining tungsten film to form a sidewall light-shielding film on the side surface of the transfer electrode;
Forming an interlayer insulating film on the entire surface;
Forming a contact hole in the interlayer insulating film on the transfer electrode;
Forming a metal light-shielding film electrically connected to the transfer electrode via the interlayer insulating film on the transfer electrode. A method of manufacturing a solid-state imaging device in which a light receiving region and a transfer region are formed on a semiconductor substrate,
When forming the transfer electrode and the light shielding film,
Forming a first insulating film on the substrate;
Forming a polycrystalline silicon film in a stripe shape while opening the light receiving region on the first insulating film;
Depositing a tungsten film on the entire surface including the inside of the opening;
Siliciding the tungsten film on the surface of the polycrystalline silicon film by heat treatment;
Removing the remaining tungsten film to form a transfer electrode comprising the polycrystalline silicon film and the silicided tungsten film;
Forming an interlayer insulating film on the entire surface;
Forming a contact hole in the interlayer insulating film on the transfer electrode;
Forming a metal light-shielding film electrically connected to the transfer electrode via the interlayer insulating film on the transfer electrode.

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