JP2008270254A - Light-receiving element, optical disc device equipped with this light-receiving element and manufacturing method of light-receiving element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-receiving element capable of improving a leak current between light-receiving regions without causing deterioration of cross talk characteristics, and to provide an optical disc device equipped with this light-receiving element and a manufacturing method of the light-receiving element. <P>SOLUTION: This light-receiving element 1 has a structure in which a first light-receiving element 4a and a second light-receiving element 4b are formed via a separation region 2 so as to be adjacent to each other, and a reflection preventing film 5 is formed on each of the regions 4a and 4b, wherein a conductive film 6 is provided on the separation region 2 between the first light-receiving region 4a and the second light-receiving region 4b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light receiving element having a structure in which a light receiving region is divided into a plurality of parts, an optical disc apparatus including the light receiving element, and a method for manufacturing the light receiving element.

  A light receiving element used for an optical pickup such as a DVD player or a next generation disk player has a structure in which a light receiving region is divided into a plurality of parts, and receives a laser beam reflected by a disk surface to receive an RF (Radio Frequency) signal. In addition, a tracking error signal for causing the laser beam spot to follow the groove on the disk surface and a focus error signal for focusing the laser beam on the disk surface are output.

  Conventional light receiving elements generally have a structure in which a p-type semiconductor substrate has a plurality of n-type semiconductor regions separated by a p-type isolation region, as shown in Patent Document 1. For example, in the conventional light receiving element 101 shown in FIG. 12, an n-type semiconductor layer 112 epitaxially grown on a p-type semiconductor substrate 111 is formed, and an isolation region 102 made of a p-type semiconductor layer 115 is formed on the n-type semiconductor layer 112. The n-type semiconductor layers 103 and 103 having a higher concentration than the n-type semiconductor layer 112 are formed adjacent to each other through the isolation region 102, thereby providing a structure in which a plurality of light receiving regions 104a and 104b are provided. A photodiode is formed in each of the light receiving regions 104a and 104b by a PN junction between the n-type semiconductor layer 112 and the p-type semiconductor substrate 111.

Further, when the light receiving element 101 receives blue-violet laser light having an oscillation wavelength of about 405 nm, it is difficult to obtain sufficient sensitivity. Therefore, an antireflection film 105 is provided after removing the interlayer film on the light receiving element 101. Yes.
JP-A-7-183563

However, since the antireflection film 105 of the light receiving element 101 is formed of a laminated film of the SiO ₂ film 113 and the Si ₃ N ₄ film 114, a pre-process for performing diffusion or the like on the wafer or a post-process for performing assembly. In the middle of this, the Si ₃ N ₄ film 114 is charged, the conductivity type of the surface 106 on the separation region 102 between the light receiving regions 104a and 104b is reversed, and a leakage current is generated between the light receiving regions 104a and 104b. Could occur.

  As a first method for preventing this inversion, as in the light receiving element 121 shown in FIG. 13, the separation region 102 between the light receiving regions 104a and 104b is separated from a thick oxide film such as the LOCOS oxide film 116 and p. It is conceivable to form a structure formed with the type semiconductor layer 115. In the case of this structure, by forming the LOCOS oxide film 116 thick, it is possible to prevent inversion of the conductivity type of the separation region surface 106 due to charging of the antireflection film 105. However, at the same time, in the photodiodes formed in the light receiving regions 104a and 104b, the light receiving sensitivity to the incidence of laser light in the vicinity of the separation region 102 is lowered, and the photodiodes formed in the light receiving regions 104a and 104b. There was a risk of deteriorating the crosstalk characteristics. Here, as shown in FIG. 15, the crosstalk characteristic between the photodiodes is the current Ia generated by the photodiode formed in the light receiving region 104a when the beam spot is irradiated in the vicinity of the separation region 102 in the light receiving element. And the current Ib generated by the photodiode formed in the light receiving region 104b is preferably substantially the same as the currents Ia and Ib when the light receiving regions 104a and 104b are individually irradiated with the beam spots.

  As a second method for preventing this inversion, the impurity concentration of the surface 106 of the isolation region 102 is further increased to provide a high-concentration p-type semiconductor layer 117 as in the light receiving element 131 shown in FIG. It can be considered to be a structure. In this case, by increasing the surface concentration of the separation region 102, it is possible to prevent inversion of the conductivity type of the separation region surface 106 due to charging of the antireflection film 105. However, since recombination of carriers increases on the surface 106 of the separation region 102, at the same time, the photodiodes formed in the light receiving regions 104a and 104b with respect to the incidence of laser light in the vicinity of the separation region 102. Sensitivity is lowered, and there is a possibility that the crosstalk characteristics between the photodiodes are deteriorated. Further, in order to secure the withstand voltage of the photodiodes formed in the light receiving regions 104a and 104b, it is necessary to increase the distance between the isolation region 102 and the n-type semiconductor layer 103, and the parasitic capacitance of the light receiving regions 104a and 104b increases. Could lead to

  In view of the above points, the present invention provides a light receiving element in which leakage current between photodiodes formed in each light receiving region is suppressed without deteriorating crosstalk characteristics, an optical disc apparatus including the light receiving element, and a light receiving element. A manufacturing method is provided.

  According to a first aspect of the present invention, in the light receiving element in which the first light receiving region and the second light receiving region are formed adjacent to each other through the separation region and an antireflection film is formed on these regions, the first light receiving region is formed. A conductive film is provided on the antireflection film between the region and the second light receiving region.

  The invention according to claim 2 is the invention according to claim 1, wherein the conductive film is formed on the antireflection film between the first light receiving region and the separation region, the second light receiving region, and the second light receiving region. It is respectively provided on the antireflection film between the separation regions.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a contact electrode for applying a voltage to the conductive film is formed.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the conductive film is a film formed by mixing impurities into silicon or a film formed of metal silicide. It is characterized by being.

  According to a fifth aspect of the present invention, there is provided a driving unit that holds and rotates an optical disk, a light emitting element that irradiates the optical disk with laser light, a light receiving element that receives reflected light of the laser light from the optical disk, In the optical disc apparatus including a processing unit that performs recording or reproduction on the optical disc according to a light reception result in the light receiving element, the light receiving element causes the first light receiving region and the second light receiving region to be adjacent to each other through the separation region. An antireflection film is formed on these regions, and a conductive film is provided on the antireflection film between the first light receiving region and the second light receiving region.

  According to a sixth aspect of the present invention, there is provided the first conductive type semiconductor substrate, a step of forming a second conductive type first semiconductor layer on the semiconductor substrate, and a first light receiving formed on the first semiconductor layer. Forming a separation region for separating the region and the second light receiving region, forming an antireflection film on the first semiconductor layer, a region in which the first light receiving region is formed, and the second light receiving Forming a conductive film selectively on the antireflection film between the region where the region is to be formed, and implanting a second conductivity type impurity using the conductive film as a mask and the first light receiving region and the first And a step of forming two light receiving regions.

  According to the present invention, in the light receiving element in which the first light receiving region and the second light receiving region are formed adjacent to each other through the separation region, and the antireflection film is formed on these regions, the first light receiving region and the second light receiving region are formed. Since the conductive film is provided on the antireflection film between the light receiving region and the conductive film, the inversion of the surface of the separation region can be suppressed by this conductive film, and the leakage current between the light receiving regions due to charging of the antireflection film is suppressed. . Accordingly, the width of the separation region that separates the light receiving regions can be further reduced, and the crosstalk characteristics between the photodiodes formed in the light receiving regions can be improved. Further, unlike the conventional light receiving element 131 shown in FIG. 14, it is not necessary to increase the surface concentration of the isolation region, so that it is possible to suppress a decrease in the breakdown voltage of the photodiode and an increase in the capacitance between the cathode and the anode of the photodiode.

  The optical disk apparatus according to the present embodiment includes a driving unit that holds and rotates the optical disk, a light emitting element that irradiates the optical disk with laser light, a light receiving element that receives the reflected light of the laser light from the optical disk, and the light receiving element. And a control unit that performs recording or reproduction on the optical disc according to the light reception result of the element, and particularly has a feature in the light receiving element.

  That is, the light receiving element is formed such that the first light receiving region and the second light receiving region are adjacent to each other through the separation region, an antireflection film is formed on these regions, and the first light receiving region, the second light receiving region, A conductive film is provided on the separation region between the two.

  As described above, since the light receiving element according to this embodiment is provided with the conductive film, the surface of the separation region is applied by applying a potential so that the conductivity type of the surface of the separation region is not reversed. And the leakage current between the light receiving regions due to charging of the antireflection film can be suppressed. Accordingly, the width of the separation region that separates the light receiving regions can be further reduced, and the crosstalk characteristics between the photodiodes formed in the light receiving regions can be improved.

  Further, the conductive film may be provided on the antireflection film between the first light receiving region and the separation region and on the antireflection film between the second light receiving region and the separation region, respectively.

  In this way, the parasitic capacitance formed in the area where the conductive film and the isolation region face each other can be reduced, the speed of the optical disk device can be increased, and a large capacity can be stored using a blue laser or the like. There are advantages to doing.

  A contact electrode for applying a voltage to the conductive film may be provided on the conductive film. The contact electrode is preferably provided outside the light receiving region.

  In this way, a voltage can be applied to the conductive film through the contact electrode, thereby preventing the inversion of the conductivity type on the surface of the separation region due to charging of the antireflection film and suppressing the leakage current between the light receiving regions. Can do.

  The conductive film may be a film formed by mixing impurities into silicon or a film formed of metal silicide. For example, the metal silicide alloyed with metal may be cobalt silicide, tungsten silicide, titanium silicide, molybdenum silicide, tantalum silicide, nickel silicide, or the like. In addition, when the conductive film is formed using a film formed by mixing impurities into silicon, the conductive film can be formed at the same time as the light receiving region is formed, and the production cost can be reduced.

  The method for manufacturing a light receiving element according to the present embodiment includes the step of forming a first conductive type semiconductor substrate, a second conductive type first semiconductor layer on the semiconductor substrate, and the first semiconductor layer. Forming a separation region for separating the first light receiving region and the second light receiving region to be formed; forming an antireflection film on the first semiconductor layer; and forming the first light receiving region. Forming a conductive film selectively on the antireflection film between a region and a region where the second light receiving region is formed, and implanting a second conductivity type impurity by using the conductive film as a mask. A step of forming one light receiving region and the second light receiving region.

  According to the method for manufacturing a light receiving element according to the present embodiment, the first light receiving region and the second light receiving region can be formed in a self-aligning manner by using the conductive film formed on the isolation region as a mask. .

  Embodiments of the present invention will be described below with reference to the drawings. First, the light receiving element according to the present embodiment will be described in detail. FIG. 1 is a configuration diagram showing a light receiving element according to the present embodiment. In the present embodiment, the first conductivity type is p-type and the second conductivity type is n-type.

  In the light receiving element 1 according to the present embodiment, an n-type semiconductor layer 12 is formed by epitaxial growth on a p-type semiconductor substrate 11 formed by adding a p-type impurity to a silicon substrate. N-type semiconductor layers 3a and 3b having an impurity concentration higher than that of n-type semiconductor layer 12 are formed, and in order to separate these n-type semiconductor layers 3a and 3b, a p-type isolation region is formed in n-type semiconductor layer 12. 2 is formed.

  Here, the regions separated via the separation region 2 are referred to as a first light receiving region 4a and a second light receiving region 4b, respectively. The first light receiving region 4 a is formed of a p-type semiconductor substrate 11, an n-type semiconductor layer 12, and an n-type semiconductor layer 3 a, and the first light-receiving region is formed by a PN junction between the p-type semiconductor substrate 11 and the n-type semiconductor layer 12. A photodiode is formed at 4a. The second light receiving region 4 b is formed of the p-type semiconductor substrate 11, the n-type semiconductor layer 12 and the n-type semiconductor layer 3 b, and is secondly formed by a PN junction between the p-type semiconductor substrate 11 and the n-type semiconductor layer 12. A photodiode is formed in the light receiving region 4b. These photodiodes have a p-type semiconductor substrate 11 as an anode and an n-type semiconductor layer 12 as a cathode.

  An antireflection film 5 is formed on the light receiving regions 4a and 4b and the separation region 2, and a conductive film is formed on the entire surface of the separation region 2 between the first light receiving region 4a and the second light receiving region 4b. 6 is formed.

  A contact electrode for applying a voltage is further connected to the conductive film 6 outside the light receiving region. By applying a voltage between the contact electrode and the separation region 2 from the wiring layer, the conductive type on the surface of the separation region 2 can be obtained. Prevent inversion. Here, the voltage applied to the conductive film 6 through the contact electrode is a voltage on the cathode side of the photodiode formed in the light receiving regions 4a and 4b so that the conductivity type inversion of the surface of the isolation region 2 does not occur. It is better to apply the above.

  The conductive film 6 was formed by implanting As impurities into a polycrystalline silicon polysilicon film. The metal silicide film may be cobalt silicide, tungsten silicide, titanium silicide, molybdenum silicide, tantalum silicide, nickel silicide, or the like.

  Here, the antireflection film 5 is formed of a laminated film of the silicon oxide film 13 and the silicon nitride film 14. For example, the thickness and material of the antireflection film 5 are optimized so that blue-violet laser light having an oscillation wavelength of 405 nm can enter the light receiving regions 4a and 4b. In particular, the number of layers of the antireflection film 5 is not limited to the two-layer film described above, and may be a single layer film or a multilayer film of three or more layers as long as it can function as an antireflection film. It may be a thing. The silicon nitride film is easily charged by plasma processing such as plasma CVD in the wafer processing step for forming the light receiving element 1 and scribing processing in the assembly step.

  According to the light receiving element 1 according to the present embodiment, the conductive film 6 is formed leaving a polysilicon film in a part on the antireflection film 5 between the first light receiving region 4a and the second light receiving region 4b. In addition, by applying a potential to the conductive film 6 so that the conductivity type of the surface of the isolation region 2 does not invert, the inversion of the surface of the isolation region 2 can be suppressed, and the antireflection film 5 is charged. Leakage current between the light receiving regions 4a and 4b due to is suppressed. Therefore, the width of the separation region for separating the light receiving regions 4a and 4b can be further reduced, and the crosstalk characteristics between the photodiodes formed in the light receiving regions 4a and 4b can be improved. Further, unlike the conventional light receiving element 131 shown in FIG. 14, it is not necessary to increase the surface concentration of the isolation region, so that it is possible to suppress a decrease in breakdown voltage of the light receiving element and an increase in capacitance between the cathode and anode of the light receiving element.

  A light receiving element 1 ′ shown in FIG. 2 is obtained by forming the conductive film 6 of the light receiving element 1 of FIG. 1 described above into a sidewall shape. FIG. 2 is a configuration diagram showing another light receiving element 1 ′ according to the present embodiment. FIG. 3 is a plan view showing another light receiving element 1 ′ according to the present embodiment.

  As in the light receiving element 1, the light receiving element 1 ′ according to the present embodiment is formed with the light receiving regions 4a and 4b and the separation region 2, and the antireflection film 5 is formed on these regions. The film formation is different. That is, as shown in FIG. 2, the light receiving element 1 ′ removes the central portion of the polysilicon film formed on the entire surface of the separation region 2 between the light receiving regions 4a and 4b, leaving the polysilicon film at the end portion. A conductive film 6 'is formed. In other words, the structure is obtained by removing the central portion of the conductive film 6 of the light receiving element 1.

  Further, as shown in FIG. 3, the conductive film 6 'is formed to extend outside each light receiving region, and forms a contact electrode 10 for applying a voltage to the conductive film 6' outside the light receiving regions 4a and 4b. The contact electrode 10 is electrically connected to a wiring layer (not shown). The narrower the width W1 of the conductive film 6 ', the smaller the parasitic capacitance generated by the antireflection film.

  According to the light receiving element 1 ′ according to the present embodiment, the conductive film 6 ′ is formed leaving a polysilicon film in a part on the separation region 2 between the light receiving regions 4 a and 4 b, and the conductive film 6 By applying a voltage to ', reversal of the surface of the separation region 2 due to charging of the antireflection film 5 can be suppressed, and leakage current between the light receiving regions 4a and 4b can be suppressed. Therefore, the width of the separation region that separates the light receiving regions 4a and 4b can be further reduced, and the crosstalk characteristics between the photodiodes formed in each light receiving region can be improved. Further, unlike the conventional light receiving element 131 shown in FIG. 14, it is not necessary to increase the surface concentration of the isolation region, so that it is possible to suppress a decrease in breakdown voltage of the light receiving element and an increase in capacitance between the cathode and anode of the light receiving element.

  Furthermore, the sidewall-shaped conductive film 6 ′ is formed in each of the light receiving regions 4 a and 4 b because the surface potential of the isolation region 2 is always prevented from being inverted by applying a voltage to the upper contact electrode 10. Even when a potential difference occurs between the cathodes of the photodiodes to be operated, the MOS operation can be prevented.

  Further, compared to the case where the polysilicon conductive film is left on the entire surface of the isolation region 2, the facing area between the antireflection film 5 and the isolation region 2 of the polysilicon conductive film 6 ′ can be reduced, and the polysilicon conductive An increase in parasitic capacitance formed by the film 6 ′ and the isolation region 2 can be suppressed.

  Further, since the conductive film 6 ′ having a sidewall shape can be formed narrower than the width of the conductive film 6 formed on the entire surface, the resistance of the conductive film 6 ′ is increased. As a result, a large resistance is added to the parasitic capacitance formed by the polysilicon conductive film 6 ′ and the isolation region 2, and the parasitic capacitance becomes relatively invisible, so that the speed of the light receiving element can be increased. it can.

  Moreover, the coupling between the cathodes of adjacent photodiodes is formed by the conductive film 6 in the case of the conductive film 6 leaving the polysilicon film on the entire surface, whereas in the structure of the light receiving element 1 ′, Since it is formed by the capacitance of the side wall-shaped polysilicon conductive film 6 ′ and the insulating film therebetween, the impedance is increased, and the frequency characteristics of the photodiodes formed in the light receiving regions 4a and 4b are also improved in this respect. In addition, it is possible to increase the speed that can cope with large-capacity recording using a blue-violet laser or the like.

  An optical disc apparatus provided with the above-described light receiving element 1 will be described. FIG. 4 is a diagram showing a schematic configuration of the optical disc apparatus according to the present embodiment. The optical disk device provided with the light receiving element 1 ′ has the same configuration as the optical disk device provided with the light receiving element 1, and is therefore omitted here.

  The optical disc device 21 according to the present embodiment includes a driving unit 23 that holds and rotates the optical disc 25, a light emitting element 22 that irradiates the optical disc 25 with a blue-violet laser beam having an oscillation wavelength of 405 nm, and an optical disc 25 that uses laser light. And a processing circuit 24 that is a processing unit that performs recording or reproduction on the optical disc 25 in accordance with the light reception result of the light receiving element. In particular, the light receiving element 1 has a structure in which a light receiving region is divided into a plurality (here, four), and the light receiving regions are adjacent to each other via a separation region 2 as shown in FIG. The antireflection film 5 is formed on these regions, and the conductive film 6 is provided on the antireflection film 5 between the light receiving regions.

  The light receiving element 1 not only receives the laser light reflected by the surface of the optical disk 25 and outputs an RF (Radio Frequency) signal, but also causes the laser light spot to follow a groove on the disk surface. A tracking error signal and a focus error signal for focusing the laser beam on the disk surface are output.

  As described above, the optical disc device 21 according to the present embodiment uses the above-described characteristic light receiving elements 1 and 1 ′ as a light receiving element that outputs an RF signal and various error signals, thereby improving the quality. In addition, the speed can be increased.

  A method for manufacturing the light receiving element 1 ′ having the sidewall-shaped conductive film 6 ′ will be specifically described with reference to the drawings. 5 to 11 show process diagrams of a method for manufacturing the light receiving element 1 ′ including the sidewall-shaped conductive film according to the present embodiment.

  First, as shown in FIG. 5, an n-type semiconductor layer 12 is formed by epitaxial growth on a p-type semiconductor substrate 11 obtained by adding a p-type impurity to a silicon substrate. For example, the n-type semiconductor layer 12 is formed with a thickness of about 1 Ωcm and a thickness of about 1 μm.

  Next, as shown in FIG. 6, a p-type isolation region 2 is formed by ion implantation to separate the regions that are adjacent light receiving regions. This separation region 2 is an isolation region. For example, the p-type isolation region may be formed by ion implantation by diffusion.

  Next, as shown in FIG. 7, a silicon oxide film 13 is formed by thermal oxidation or the like, and then a silicon nitride film 14 is formed by a CVD (Chemical Vapor Deposition) method. The antireflection film 5 is composed of a silicon oxide film 13 and a silicon nitride film 14. For example, the silicon oxide film 13 is formed with a thickness of about 10 nm, and the silicon nitride film 14 is formed with a thickness of about 50 nm.

  Next, as shown in FIG. 8, a silicon oxide film is formed by a CVD method, and then a patterning process is performed by using a photoresist or the like by a photolithography method, for example, wet etching such as citric acid or RIE (Reactive Ion). The silicon oxide film 7 is selectively left on the antireflection film 5 on the isolation region 2 by dry etching such as Etching. For example, the silicon oxide film 7 is formed with a film thickness of about 200 nm.

  Next, as shown in FIG. 9, a conductive polysilicon film 15 is formed by CVD. For example, the polysilicon film 15 is formed with a film thickness of about 300 nm.

Next, as shown in FIG. 10, the entire surface is etched back to form a sidewall-shaped polysilicon conductive film 6 ′ on the side wall of the silicon oxide film 7. Further, by performing ion implantation of arsenic (As) impurities, the silicon oxide film 7 and the sidewall-shaped polysilicon conductive film 6 'serve as a mask, so that the n-type semiconductor layers 3a and 3b are formed in a self-aligning manner. The At this time, the n-type semiconductor layers 3a and 3b are not formed in the light receiving regions 4a and 4b immediately below the silicon oxide film 7 and the sidewall-shaped polysilicon conductive film 6 ′. For example, As impurity ion implantation is performed at an energy of 30 keV and an impurity concentration of about 1E15 (1 / cm ² ).

  Next, as shown in FIG. 11, after the heat treatment for forming the interlayer film and activating the diffused n-type semiconductor layers 3a and 3b, the first light receiving region 4a and the second light receiving region are finally obtained. The anti-reflection film 5 is exposed by removing the interlayer film on 4b. The light receiving element 1 ′ is formed with the separation region 2 sandwiched between the first light receiving region 4 a and the second light receiving region 4 b, and a sidewall-shaped polysilicon conductive film 6 is formed on the separation region 2 via an antireflection film 5. 'Is formed.

  As shown in FIG. 3, the sidewall-shaped polysilicon conductive film 6 'of the present light-receiving element is formed to extend outside the light-receiving regions 4a and 4b, and the sidewall-shaped polysilicon conductive film 6a outside the light-receiving regions 4a and 4b. A contact electrode 10 is formed on the silicon conductive film 6 ′, and the contact electrode 10 and a wiring layer (not shown) are electrically connected. Therefore, the light receiving element 1 ′ according to the present embodiment can be obtained.

  Although a detailed description of the manufacturing method of the light receiving element 1 according to the present embodiment is omitted, after the manufacturing steps shown in FIGS. 5 to 7 are performed, the polysilicon film 15 is formed by the CVD method. Etch back is performed to form a polysilicon conductive film 6. Since the polysilicon conductive film 6 serves as a mask when As impurities are ion-implanted, the light receiving region 4 is formed in a self-aligning manner. The light receiving element 1 according to the present embodiment can be obtained.

  According to the method for manufacturing a light receiving element according to the present embodiment, when ion implantation for forming a light receiving region is performed, the polysilicon conductive film serves as a mask, and the light receiving regions 4a and 4b are n-type semiconductors in a self-aligning manner. Layers 3a and 3b can be formed. The semiconductor substrate may be a semi-insulating substrate such as gallium (Ga) or arsenic (As).

  In the light receiving element according to the present embodiment, the isolation region is formed as a high concentration isolation region by ion implantation of As impurities, but may be formed of a LOCOS oxide film.

  Although one embodiment according to the present invention has been specifically described, the present invention is not limited to the above-described embodiment, and various modifications based on the technical idea of the present invention are possible.

It is a figure which shows the structure of the light receiving element in this Embodiment. It is a figure which shows the structure of the other light receiving element in this Embodiment. It is a top view which shows the light receiving element of FIG. It is a figure which shows schematic structure of the optical disk apparatus in this Embodiment. It is a figure which shows the manufacturing process of the light receiving element of FIG. It is a figure which shows the manufacturing process of the light receiving element of FIG. It is a figure which shows the manufacturing process of the light receiving element of FIG. It is a figure which shows the manufacturing process of the light receiving element of FIG. It is a figure which shows the manufacturing process of the light receiving element of FIG. It is a figure which shows the manufacturing process of the light receiving element of FIG. It is a figure which shows the manufacturing process of the light receiving element of FIG. It is a figure which shows the structure of the conventional light receiving element. It is a figure which shows the structure of the conventional light receiving element. It is a figure which shows the structure of the conventional light receiving element. It is a figure for demonstrating the crosstalk characteristic between photodiodes.

Explanation of symbols

1, 1 'light receiving element 2 isolation region 3 photodiode 4 light receiving region 5 antireflection film 6, 6' conductive film 7 silicon oxide film 10 contact electrode 11 semiconductor substrate 12 first semiconductor layer 13 silicon oxide film 14 silicon nitride film 15 poly Silicon film

Claims (6)

In the light receiving element in which the first light receiving region and the second light receiving region are formed adjacent to each other through the separation region, and the antireflection film is formed on these regions,
A light receiving element, wherein a conductive film is provided on the antireflection film between the first light receiving region and the second light receiving region. The conductive film is provided on the antireflection film between the first light receiving region and the separation region and on the antireflection film between the second light receiving region and the separation region, respectively. The light receiving element according to claim 1. The light receiving element according to claim 1, wherein a contact electrode for applying a voltage to the conductive film is formed. The light receiving element according to any one of claims 1 to 3, wherein the conductive film is a film formed by mixing impurities into silicon or a film formed of metal silicide. Drive means for holding and rotating the optical disk, a light emitting element for irradiating the optical disk with laser light, a light receiving element for receiving the reflected light of the laser light from the optical disk, and the light receiving element according to the light receiving result in the light receiving element In an optical disc apparatus provided with a processing unit that performs recording or reproduction on an optical disc,
The light receiving element is formed such that a first light receiving region and a second light receiving region are adjacent to each other via a separation region, an antireflection film is formed on these regions, and the first light receiving region and the second light receiving region are formed. An optical disk device, wherein a conductive film is provided on the antireflection film between the light receiving region. Forming a first conductive type semiconductor substrate and a second conductive type first semiconductor layer on the semiconductor substrate;
Forming a separation region for separating the first light receiving region and the second light receiving region formed in the first semiconductor layer;
Forming an antireflection film on the first semiconductor layer;
Selectively forming a conductive film on the antireflection film between a region where the first light receiving region is formed and a region where the second light receiving region is formed;
A method of manufacturing a light receiving element, comprising: forming the first light receiving region and the second light receiving region by implanting a second conductivity type impurity using the conductive film as a mask.

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