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JP2007305868A - Light receiving element - Google Patents

Light receiving element Download PDF

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JP2007305868A
JP2007305868A JP2006134094A JP2006134094A JP2007305868A JP 2007305868 A JP2007305868 A JP 2007305868A JP 2006134094 A JP2006134094 A JP 2006134094A JP 2006134094 A JP2006134094 A JP 2006134094A JP 2007305868 A JP2007305868 A JP 2007305868A
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light receiving
photodiode
receiving element
type
light
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Yoshitsugu Kamihira
祥嗣 上平
Junji Fujino
純士 藤野
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Rohm Co Ltd
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Rohm Co Ltd
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Priority to PCT/JP2007/059906 priority patent/WO2007132823A1/en
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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10F—INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
    • H10F30/00—Individual radiation-sensitive semiconductor devices in which radiation controls the flow of current through the devices, e.g. photodetectors
    • H10F30/20—Individual radiation-sensitive semiconductor devices in which radiation controls the flow of current through the devices, e.g. photodetectors the devices having potential barriers, e.g. phototransistors
    • H10F30/21—Individual radiation-sensitive semiconductor devices in which radiation controls the flow of current through the devices, e.g. photodetectors the devices having potential barriers, e.g. phototransistors the devices being sensitive to infrared, visible or ultraviolet radiation
    • H10F30/22—Individual radiation-sensitive semiconductor devices in which radiation controls the flow of current through the devices, e.g. photodetectors the devices having potential barriers, e.g. phototransistors the devices being sensitive to infrared, visible or ultraviolet radiation the devices having only one potential barrier, e.g. photodiodes
    • H10F30/221—Individual radiation-sensitive semiconductor devices in which radiation controls the flow of current through the devices, e.g. photodetectors the devices having potential barriers, e.g. phototransistors the devices being sensitive to infrared, visible or ultraviolet radiation the devices having only one potential barrier, e.g. photodiodes the potential barrier being a PN homojunction
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10F—INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
    • H10F30/00—Individual radiation-sensitive semiconductor devices in which radiation controls the flow of current through the devices, e.g. photodetectors
    • H10F30/20—Individual radiation-sensitive semiconductor devices in which radiation controls the flow of current through the devices, e.g. photodetectors the devices having potential barriers, e.g. phototransistors
    • H10F30/21—Individual radiation-sensitive semiconductor devices in which radiation controls the flow of current through the devices, e.g. photodetectors the devices having potential barriers, e.g. phototransistors the devices being sensitive to infrared, visible or ultraviolet radiation
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10F—INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
    • H10F77/00—Constructional details of devices covered by this subclass
    • H10F77/10—Semiconductor bodies
    • H10F77/14—Shape of semiconductor bodies; Shapes, relative sizes or dispositions of semiconductor regions within semiconductor bodies

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  • Light Receiving Elements (AREA)

Abstract

【課題】視感度特性に近い分光感度特性を有し、分光感度特性を視感度特性に近づけるための光学フィルタを不要とすることができる、受光素子を提供すること。
【解決手段】受光素子１では、ｎ型基板２の表層部にｐ型層３が埋設され、そのｐ型層３の表層部にｎ型層４が埋設されている。そして、ｐ型層３に接続された第２アノード電極８とｎ型層４に接続された第２カソード電極９とが配線１４で接続されることにより、ｐ型層３とｎ型層４とのｐｎ接合からなる第２のフォトダイオードＰＤ２は、そののアノード−カソード間が短絡されている。これにより、受光素子１からは、ｎ型基板２とｐ型層３とのｐｎ接合からなる第１のフォトダイオードＰＤ１での光電変換によって生じる光電流のみが、ｎ型基板２に接続された第１カソード電極６から光検出信号として出力される。
【選択図】図１Provided is a light receiving element that has a spectral sensitivity characteristic close to a visual sensitivity characteristic and can eliminate the need for an optical filter for bringing the spectral sensitivity characteristic close to the visual sensitivity characteristic.
In a light receiving element, a p-type layer is embedded in a surface layer portion of an n-type substrate, and an n-type layer is embedded in a surface layer portion of the p-type layer. Then, the second anode electrode 8 connected to the p-type layer 3 and the second cathode electrode 9 connected to the n-type layer 4 are connected by the wiring 14, whereby the p-type layer 3, the n-type layer 4, The second photodiode PD2 composed of the pn junction is short-circuited between its anode and cathode. Thereby, from the light receiving element 1, only the photocurrent generated by the photoelectric conversion in the first photodiode PD <b> 1 formed of the pn junction between the n-type substrate 2 and the p-type layer 3 is connected to the n-type substrate 2. 1 is output as a light detection signal from the cathode electrode 6.
[Selection] Figure 1

Description

この発明は、フォトダイオード構造を有する受光素子に関する。   The present invention relates to a light receiving element having a photodiode structure.

たとえば、携帯電話機やＰＤＡ（Personal Digital Assistants）、ノートＰＣ（Personal Computer）などのモバイル機器では、周囲の明るさを検出するための照度センサが備えられている。そして、この照度センサにより検出される周囲の明るさに応じて、液晶画面の輝度が自動調整される。
照度センサには、フォトダイオード構造を有する受光素子が用いられている。従来の典型的な受光素子は、たとえば、ｎ型基板の表層部に、ｐ型不純物領域が形成された構造を有している。この受光素子では、ｐ型不純物領域の表面（受光面）から入射する光が、ｐ型不純物領域とｎ型基板とのｐｎ接合からなるフォトダイオードにより光電変換され、この光電変換により生じる光電流が、ｎ型基板に接続されたカソード電極から出力される。
特開平７−３８１３６号公報 For example, mobile devices such as mobile phones, PDAs (Personal Digital Assistants), and notebook PCs (Personal Computers) are provided with an illuminance sensor for detecting ambient brightness. The brightness of the liquid crystal screen is automatically adjusted according to the ambient brightness detected by the illuminance sensor.
A light receiving element having a photodiode structure is used for the illuminance sensor. A conventional typical light receiving element has, for example, a structure in which a p-type impurity region is formed in a surface layer portion of an n-type substrate. In this light receiving element, light incident from the surface (light receiving surface) of the p-type impurity region is photoelectrically converted by a photodiode comprising a pn junction between the p-type impurity region and the n-type substrate, and a photocurrent generated by this photoelectric conversion is generated. , And output from the cathode electrode connected to the n-type substrate.
Japanese Patent Laid-Open No. 7-38136

ところで、光に対する人間の目の感度（視感度）は、波長が約５５５ｎｍの光に対してピークとなり、波長が約４００ｎｍ以下の範囲および約７２０ｎｍ以上の範囲の光に対して零となる。また、波長が約４００〜５５５ｎｍの範囲の光に対しては、短い波長の光ほど視感度が小さく、波長が約５５５〜７２０ｎｍの範囲の光に対しては、長い波長の光ほど視感度が小さくなる。   By the way, the sensitivity (visual sensitivity) of the human eye to light has a peak for light having a wavelength of about 555 nm, and is zero for light having a wavelength of about 400 nm or less and about 720 nm or more. For light in the wavelength range of about 400 to 555 nm, the shorter the light wavelength, the lower the visibility, and for the light in the wavelength range of about 555 to 720 nm, the longer the wavelength, the higher the visibility. Get smaller.

そこで、従来の受光素子では、分光感度が約５５５ｎｍの波長を有する光に対してピークとなるように、フォトダイオードの受光面からの深さ（ｐ型不純物領域の深さ）が設定されている。しかし、このような深さでは、ｐ型不純物領域の表面から入射する波長４００ｎｍ以下の光がフォトダイオード（ｐｎ接合）に達するために、波長４００ｎｍ以下の光に対する感度が零にならない。このような分光感度特性を有する受光素子が照度センサに用いられ、たとえば、その照度センサがモバイル機器に備えられた場合、周囲の明るさの変化に対して、液晶画面の輝度が良好に調整されないおそれがある。そのため、従来の受光素子を照度センサに用いる場合には、ｐ型不純物領域の表面に入射する光から波長４００ｎｍ以下の光を除去するための高価な光学フィルタが必要であった。   Therefore, in the conventional light receiving element, the depth from the light receiving surface of the photodiode (depth of the p-type impurity region) is set so that the spectral sensitivity reaches a peak with respect to light having a wavelength of about 555 nm. . However, at such a depth, since light with a wavelength of 400 nm or less incident from the surface of the p-type impurity region reaches the photodiode (pn junction), the sensitivity to light with a wavelength of 400 nm or less does not become zero. A light receiving element having such spectral sensitivity characteristics is used in an illuminance sensor. For example, when the illuminance sensor is provided in a mobile device, the brightness of the liquid crystal screen is not adjusted well with respect to changes in ambient brightness. There is a fear. Therefore, when a conventional light receiving element is used for an illuminance sensor, an expensive optical filter for removing light having a wavelength of 400 nm or less from light incident on the surface of the p-type impurity region is necessary.

そこで、この発明の目的は、視感度特性に近い分光感度特性を有し、分光感度特性を視感度特性に近づけるための光学フィルタを不要とすることができる、受光素子を提供することである。   Accordingly, an object of the present invention is to provide a light receiving element that has a spectral sensitivity characteristic close to the visibility characteristic and can eliminate the need for an optical filter for bringing the spectral sensitivity characteristic close to the visibility characteristic.

前記の目的を達成するための請求項１記載の発明は、第１導電型を有する第１半導体層と、この第１半導体層の表層部に埋設され、前記第１導電型とは異なる第２導電型を有する第２半導体層と、この第２半導体層の表層部に埋設され、前記第１導電型を有する第３半導体層と、前記第２半導体層と前記第３半導体層とを接続する配線とを含むことを特徴とする、受光素子である。   According to a first aspect of the present invention for achieving the above object, a first semiconductor layer having a first conductivity type and a second semiconductor layer embedded in a surface layer portion of the first semiconductor layer and different from the first conductivity type. A second semiconductor layer having a conductivity type, a third semiconductor layer embedded in a surface layer portion of the second semiconductor layer and having the first conductivity type, and connecting the second semiconductor layer and the third semiconductor layer. A light receiving element including a wiring.

この受光素子では、第１導電型（ｐ型またはｎ型）の第１半導体層の表層部に、第２導電型（ｎ型またはｐ型）の第２半導体層が埋設され、この第２半導体層の表層部に、第１導電型の第３半導体層が埋設されている。これにより、受光素子には、第１半導体層と第２半導体層とのｐｎ接合からなる第１のフォトダイオードと、第２半導体層と第３半導体層とのｐｎ接合からなる第２のフォトダイオードとが、受光面をなす第１半導体層、第２半導体層および第３半導体層の表面からの深さを異ならせて形成されている。すなわち、受光面から相対的に深い位置に第１のフォトダイオードが形成され、受光面から相対的に浅い位置に第２のフォトダイオードが形成されている。   In this light receiving element, a second semiconductor layer of the second conductivity type (n-type or p-type) is embedded in the surface layer portion of the first semiconductor layer of the first conductivity type (p-type or n-type). A third semiconductor layer of the first conductivity type is embedded in the surface layer portion of the layer. Accordingly, the light receiving element includes a first photodiode composed of a pn junction between the first semiconductor layer and the second semiconductor layer, and a second photodiode composed of a pn junction between the second semiconductor layer and the third semiconductor layer. Are formed at different depths from the surfaces of the first semiconductor layer, the second semiconductor layer, and the third semiconductor layer forming the light receiving surface. That is, the first photodiode is formed at a relatively deep position from the light receiving surface, and the second photodiode is formed at a relatively shallow position from the light receiving surface.

この受光素子では、第２のフォトダイオードが形成されているので、受光面から入射する光のうち、第２のフォトダイオードで光電変換されない光のみが第１のフォトダイオードに到達する。したがって、従来の受光素子（に形成されているフォトダイオード）の分光感度と比較して、第１のフォトダイオードの分光感度を、短波長域で下げることができる。   In this light receiving element, since the second photodiode is formed, only light that is not photoelectrically converted by the second photodiode among the light incident from the light receiving surface reaches the first photodiode. Therefore, the spectral sensitivity of the first photodiode can be lowered in a short wavelength region as compared with the spectral sensitivity of the conventional light receiving element (the photodiode formed therein).

たとえば、第１のフォトダイオードの受光面からの深さを従来の受光素子におけるフォトダイオードの受光面からの深さとほぼ同じに設定し、波長４００ｎｍの光に対する第２のフォトダイオードの感度が従来の受光素子とほぼ同じとなるように、第２のフォトダイオードの受光面からの深さを設定すれば、第１のフォトダイオードの分光感度特性を、波長が約５５５ｎｍの光に対する感度がピークとなり、波長が４００ｎｍ以下の光に対する感度が零である分光感度特性とすることができる。つまり、第１のフォトダイオードの分光感度特性を、視感度特性に近づけることができる。   For example, the depth from the light receiving surface of the first photodiode is set to be substantially the same as the depth from the light receiving surface of the photodiode in the conventional light receiving element, and the sensitivity of the second photodiode with respect to light having a wavelength of 400 nm is conventional. If the depth from the light receiving surface of the second photodiode is set so as to be substantially the same as the light receiving element, the spectral sensitivity characteristic of the first photodiode has a peak sensitivity with respect to light having a wavelength of about 555 nm, Spectral sensitivity characteristics with zero sensitivity to light having a wavelength of 400 nm or less can be obtained. That is, the spectral sensitivity characteristic of the first photodiode can be brought close to the visibility characteristic.

そして、この受光素子では、第２半導体層と第３半導体層とが配線を介して接続されることにより、第２のフォトダイオードのアノード−カソード間が短絡されている。そのため、第２のフォトダイオードでの光電変換によって生じる光電流は取り出されず、第１のフォトダイオードでの光電変換によって生じる光電流のみが光検出信号として取り出される。したがって、この受光素子は、視感度特性に近い分光感度特性を有し、分光感度特性を視感度特性に近づけるための高価な光学フィルタを不要とすることができる。よって、この受光素子は、明るさを検出するための照度センサに好適に用いることができる。   In this light receiving element, the second semiconductor layer and the third semiconductor layer are connected to each other through a wiring, so that the anode and the cathode of the second photodiode are short-circuited. Therefore, the photocurrent generated by the photoelectric conversion in the second photodiode is not extracted, and only the photocurrent generated by the photoelectric conversion in the first photodiode is extracted as the light detection signal. Therefore, this light receiving element has a spectral sensitivity characteristic close to the visibility characteristic, and an expensive optical filter for bringing the spectral sensitivity characteristic close to the visibility characteristic can be eliminated. Therefore, this light receiving element can be suitably used for an illuminance sensor for detecting brightness.

また、第２のフォトダイオードでの光電変換により生じる光電流が取り出されないので、その光電流に基づいて分光感度を演算する回路が不要である。したがって、そのような演算回路を配置するためのスペースを省略することができ、受光素子のサイズの小型化を図ることができる。また、この受光素子を、演算回路などを有しないディスクリート製品として構成することもできる。さらには、第２のフォトダイオードでの光電変換により生じる光電流に基づいて分光感度を演算する演算回路が不要であるので、この受光素子は、その演算回路が有するノイズの影響を受けるおそれがなく、良好な光検出信号を出力することができる。   In addition, since a photocurrent generated by photoelectric conversion in the second photodiode is not taken out, a circuit for calculating the spectral sensitivity based on the photocurrent is unnecessary. Therefore, a space for arranging such an arithmetic circuit can be omitted, and the size of the light receiving element can be reduced. In addition, the light receiving element can be configured as a discrete product that does not have an arithmetic circuit or the like. Furthermore, since an arithmetic circuit that calculates the spectral sensitivity based on the photocurrent generated by photoelectric conversion in the second photodiode is unnecessary, the light receiving element is not likely to be affected by noise of the arithmetic circuit. A good light detection signal can be output.

以下では、この発明の実施の形態を、添付図面を参照して詳細に説明する。
図１は、この発明の一実施形態に係る受光素子の構造を示す断面図である。
この受光素子１は、第１半導体層としてのｎ型基板２を備えている。このｎ型基板２の表面は、光が入射する受光面をなしている。
ｎ型基板２の表層部には、平面視において、ｎ型基板２の周縁から所定幅を隔てた内方の領域に、その表面からｐ型不純物をドーピングすることによって、第２半導体層としてのｐ型層３が埋設されている。これにより、受光素子１には、ｎ型基板２とｐ型層３とのｐｎ接合からなる第１のフォトダイオードＰＤ１が形成されている。ｐ型層３の受光面からの深さは、その第１のフォトダイオードＰＤ１で波長５５５ｎｍの光が最も効率よく光電変換される深さとされている。 Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a sectional view showing the structure of a light receiving element according to an embodiment of the present invention.
The light receiving element 1 includes an n-type substrate 2 as a first semiconductor layer. The surface of the n-type substrate 2 forms a light receiving surface on which light is incident.
The surface layer portion of the n-type substrate 2 is doped with a p-type impurity from the surface in an inner region separated from the periphery of the n-type substrate 2 in plan view, thereby forming a second semiconductor layer. A p-type layer 3 is embedded. Thereby, in the light receiving element 1, a first photodiode PD1 formed of a pn junction between the n-type substrate 2 and the p-type layer 3 is formed. The depth from the light receiving surface of the p-type layer 3 is set to a depth at which light having a wavelength of 555 nm is most efficiently photoelectrically converted by the first photodiode PD1.

ｐ型層３の表層部には、平面視において、ｐ型層３の周縁から間隔を隔てた内方の領域に、その表面からｎ型不純物をドーピングすることによって、第３半導体層としてのｎ型層４が埋設されている。これにより、受光素子１には、第１のフォトダイオードＰＤ１よりも受光面に近い位置に、ｐ型層３とｎ型層４とのｐｎ接合からなる第２のフォトダイオードＰＤ２が形成されている。一般に、フォトダイオード構造を有する受光素子では、受光面から入射する光は波長が短いものほど浅い位置で吸収されるので、第２のフォトダイオードＰＤ２では、５５５ｎｍよりも短い波長の光が最も効率よく光電変換されることになる。   In the surface layer portion of the p-type layer 3, an n-type impurity is doped from the surface into an inner region spaced from the periphery of the p-type layer 3 in plan view. A mold layer 4 is embedded. Thereby, in the light receiving element 1, a second photodiode PD2 formed of a pn junction between the p-type layer 3 and the n-type layer 4 is formed at a position closer to the light receiving surface than the first photodiode PD1. . In general, in a light receiving element having a photodiode structure, light having a shorter wavelength is absorbed at a shallower position as the wavelength is shorter. Therefore, in the second photodiode PD2, light having a wavelength shorter than 555 nm is the most efficient. It will be photoelectrically converted.

ｎ型基板２の表面は、ＳｉＯ2またはＳｉＮからなる透明な保護膜５で覆われている。この保護膜５上には、第１カソード電極６、第１アノード電極７、第２アノード電極８および第２カソード電極９が形成されている。
第１カソード電極６は、保護膜５に形成された開口１１を介して、ｎ型基板２に接続されている。第１アノード電極７は、保護膜５に形成された開口１０を介して、ｐ型層３に接続されている。また、第１アノード電極７は、グランドライン（図示せず）に接続されて、グランド電位とされている。これにより、第１のフォトダイオードＰＤ１での光電変換によって生じる光電流は、第１カソード電極６から光検出信号として出力される。 The surface of the n-type substrate 2 is covered with a transparent protective film 5 made of SiO 2 or SiN. A first cathode electrode 6, a first anode electrode 7, a second anode electrode 8 and a second cathode electrode 9 are formed on the protective film 5.
The first cathode electrode 6 is connected to the n-type substrate 2 through the opening 11 formed in the protective film 5. The first anode electrode 7 is connected to the p-type layer 3 through the opening 10 formed in the protective film 5. The first anode electrode 7 is connected to a ground line (not shown) and is at a ground potential. Thereby, the photocurrent generated by the photoelectric conversion in the first photodiode PD1 is output from the first cathode electrode 6 as a light detection signal.

第２アノード電極８は、保護膜５に形成された開口１２を介して、ｐ型層３に接続されている。第２カソード電極９は、保護膜５に形成された開口１３を介して、ｎ型層４に接続されている。そして、第２アノード電極８と第２カソード電極９とは、保護膜５上に形成された配線１４を介して接続されている。また、第２アノード電極８は、グランドライン（図示せず）に接続されている。   The second anode electrode 8 is connected to the p-type layer 3 through the opening 12 formed in the protective film 5. The second cathode electrode 9 is connected to the n-type layer 4 through the opening 13 formed in the protective film 5. The second anode electrode 8 and the second cathode electrode 9 are connected via a wiring 14 formed on the protective film 5. The second anode electrode 8 is connected to a ground line (not shown).

以上のように、この受光素子１では、ｎ型基板２の表層部にｐ型層３が埋設され、そのｐ型層３の表層部にｎ型層４が埋設されている。これにより、受光素子１には、ｎ型基板２とｐ型層３とのｐｎ接合からなる第１のフォトダイオードＰＤ１と、ｐ型層３とｎ型層４とのｐｎ接合からなる第２のフォトダイオードＰＤ２とが、受光面をなすｎ型基板２の表面からの深さを異ならせて形成されている。   As described above, in the light receiving element 1, the p-type layer 3 is embedded in the surface layer portion of the n-type substrate 2, and the n-type layer 4 is embedded in the surface layer portion of the p-type layer 3. Thus, the light receiving element 1 includes a first photodiode PD1 composed of a pn junction between the n-type substrate 2 and the p-type layer 3, and a second pn junction composed of the p-type layer 3 and the n-type layer 4. The photodiode PD2 is formed with different depths from the surface of the n-type substrate 2 forming the light receiving surface.

第１のフォトダイオードＰＤ１は、波長が約５５５ｎｍの光が最も効率よく光電変換される深さに形成されている。第２のフォトダイオードＰＤ２が形成されていなければ、第１のフォトダイオードＰＤ１は、背景技術の項で説明した従来の受光素子と同様の分光感度特性を有する。すなわち、図２に曲線Ｃ１で示すように、波長が約７２０ｎｍ以下の光に対して感度を有し、波長が約５５５ｎｍの光に対する感度がピークとなり、波長が４００ｎｍ以下の光に対する感度が零にはならない。   The first photodiode PD1 is formed to a depth at which light having a wavelength of about 555 nm is most efficiently photoelectrically converted. If the second photodiode PD2 is not formed, the first photodiode PD1 has a spectral sensitivity characteristic similar to that of the conventional light receiving element described in the background section. That is, as shown by a curve C1 in FIG. 2, it has sensitivity to light having a wavelength of about 720 nm or less, has a peak sensitivity to light having a wavelength of about 555 nm, and has zero sensitivity to light having a wavelength of 400 nm or less. Must not.

この受光素子１では、第２のフォトダイオードＰＤ２が形成されているので、受光面から入射する光のうち、第２のフォトダイオードＰＤ２で光電変換されない光のみが第１のフォトダイオードＰＤ１に到達する。したがって、第２のフォトダイオードＰＤ２が、図２に曲線Ｃ２で示すように、波長が４００ｎｍの光に対して従来の受光素子とほぼ同じ感度を有し、かつ、約４００ｎｍの波長を有する光に対する感度がピークとなり、それよりも長い波長の光ほど感度が低下するような分光感度特性を有していれば、第１のフォトダイオードＰＤ１は、図２に曲線Ｃ３で示すように、波長が約７２０ｎｍ以下の光に対して感度を有し、波長が約５５５ｎｍの光に対する感度がピークとなり、波長が４００ｎｍ以下の光に対する感度が零である分光感度特性を有する。つまり、第１のフォトダイオードＰＤ１は、視感度特性に近い分光感度特性を有する。   In the light receiving element 1, since the second photodiode PD2 is formed, only light that is not photoelectrically converted by the second photodiode PD2 among the light incident from the light receiving surface reaches the first photodiode PD1. . Therefore, as shown by a curve C2 in FIG. 2, the second photodiode PD2 has almost the same sensitivity as a conventional light receiving element with respect to light having a wavelength of 400 nm, and with respect to light having a wavelength of about 400 nm. If the spectral sensitivity characteristic is such that the sensitivity reaches a peak and the sensitivity decreases as the wavelength of light is longer than that, the first photodiode PD1 has a wavelength of about It has sensitivity to light having a wavelength of 720 nm or less, has a peak sensitivity to light having a wavelength of about 555 nm, and has a spectral sensitivity characteristic in which the sensitivity to light having a wavelength of 400 nm or less is zero. That is, the first photodiode PD1 has a spectral sensitivity characteristic close to the visibility characteristic.

そして、ｐ型層３に接続された第２アノード電極８とｎ型層４に接続された第２カソード電極９とが配線１４を介して接続されることにより、第２のフォトダイオードＰＤ２のアノード−カソード間が短絡されている。また、第２アノード電極８は、グランドラインに接続されている。そのため、第２のフォトダイオードＰＤ２での光電変換により生成される光電流は、グランドラインに逃がされ、この受光素子１からは、第１のフォトダイオードＰＤ１での光電変換によって生じる光電流のみが第１カソード電極６から光検出信号として出力される。したがって、この受光素子１は、視感度特性に近い分光感度特性を有し、分光感度特性を視感度特性に近づけるための高価な光学フィルタを不要とすることができる。よって、この受光素子１は、明るさを検出するための照度センサに好適に用いることができる。   Then, the second anode electrode 8 connected to the p-type layer 3 and the second cathode electrode 9 connected to the n-type layer 4 are connected via the wiring 14, whereby the anode of the second photodiode PD2 is connected. -The cathode is short-circuited. The second anode electrode 8 is connected to the ground line. Therefore, the photocurrent generated by the photoelectric conversion in the second photodiode PD2 is released to the ground line, and only the photocurrent generated by the photoelectric conversion in the first photodiode PD1 is released from the light receiving element 1. Output from the first cathode electrode 6 as a light detection signal. Therefore, the light receiving element 1 has a spectral sensitivity characteristic close to the visibility characteristic, and an expensive optical filter for bringing the spectral sensitivity characteristic close to the visibility characteristic can be eliminated. Therefore, the light receiving element 1 can be suitably used for an illuminance sensor for detecting brightness.

また、この受光素子１では、第２のフォトダイオードＰＤ２での光電変換により生じる光電流が取り出されないので、その光電流に基づいて分光感度を演算する回路が不要である。したがって、そのような演算回路を配置するためのスペースを省略することができ、受光素子１のサイズの小型化を図ることができる。また、この受光素子１を、演算回路などを有しないディスクリート製品として構成することもできる。さらには、第２のフォトダイオードＰＤ２での光電変換により生じる光電流に基づいて分光感度を演算する演算回路が不要であるので、この受光素子１は、その演算回路が有するノイズの影響を受けるおそれがなく、良好な光検出信号を出力することができる。   Further, in the light receiving element 1, since a photocurrent generated by photoelectric conversion in the second photodiode PD2 is not taken out, a circuit for calculating the spectral sensitivity based on the photocurrent is unnecessary. Therefore, a space for arranging such an arithmetic circuit can be omitted, and the size of the light receiving element 1 can be reduced. The light receiving element 1 can also be configured as a discrete product that does not have an arithmetic circuit or the like. Furthermore, since an arithmetic circuit for calculating the spectral sensitivity based on the photocurrent generated by photoelectric conversion in the second photodiode PD2 is not necessary, the light receiving element 1 may be affected by noise of the arithmetic circuit. And a good light detection signal can be output.

以上、この発明の一実施形態を説明したが、この発明は他の形態で実施することもできる。たとえば、前述の実施形態では、第１アノード電極７および第２アノード電極８が別々に形成されているが、第１アノード電極７および第２アノード電極８を一体に形成してもよい。また、第１アノード電極７および開口１１を省略してもよい。さらにまた、第２アノード電極８および開口１２を省略し、第１アノード電極７をグランドラインに接続するとともに、第１アノード電極７と第２カソード電極９とを配線１４により接続してもよい。   Although one embodiment of the present invention has been described above, the present invention can be implemented in other forms. For example, in the above-described embodiment, the first anode electrode 7 and the second anode electrode 8 are formed separately, but the first anode electrode 7 and the second anode electrode 8 may be integrally formed. Further, the first anode electrode 7 and the opening 11 may be omitted. Furthermore, the second anode electrode 8 and the opening 12 may be omitted, the first anode electrode 7 may be connected to the ground line, and the first anode electrode 7 and the second cathode electrode 9 may be connected by the wiring 14.

また、前述した受光素子の各半導体部分の導電型を反転した構成が採用されてもよい。すなわち、ｐ型基板の表層部にｎ型層を埋設し、そのｎ型層の表層部にｐ型層を埋設する。そして、ｐ型基板およびｐ型層をグランドラインに接続するとともに、ｐ型層とｎ型層とを配線により接続して、ｐ型層とｎ型層とのｐｎ接合からなる第２のフォトダイオードのアノード−カソード間を短絡することにより、ｐ型基板とｎ型層とのｐｎ接合からなる第１のフォトダイオードでの光電変換によって生じる光電流のみをｎ型層に接続された電極から取り出すようにしてもよい。   Moreover, the structure which reversed the conductivity type of each semiconductor part of the light receiving element mentioned above may be employ | adopted. That is, an n-type layer is embedded in a surface layer portion of a p-type substrate, and a p-type layer is embedded in the surface layer portion of the n-type layer. Then, the p-type substrate and the p-type layer are connected to the ground line, the p-type layer and the n-type layer are connected by wiring, and the second photodiode is formed of a pn junction between the p-type layer and the n-type layer. By short-circuiting between the anode and the cathode, only the photocurrent generated by photoelectric conversion in the first photodiode formed by the pn junction between the p-type substrate and the n-type layer is taken out from the electrode connected to the n-type layer. It may be.

その他、特許請求の範囲に記載された事項の範囲で種々の設計変更を施すことが可能である。   In addition, various design changes can be made within the scope of matters described in the claims.

この発明の一実施形態に係る受光素子の構造を示す断面図である。It is sectional drawing which shows the structure of the light receiving element which concerns on one Embodiment of this invention. 図１に示す受光素子の分光感度特性を説明するための図である。It is a figure for demonstrating the spectral sensitivity characteristic of the light receiving element shown in FIG.

符号の説明Explanation of symbols

１ 受光素子
２ ｎ型基板
３ ｐ型層
４ ｎ型層
１４ 配線 1 Photodetector 2 n-type substrate 3 p-type layer 4 n-type layer 14 wiring

Claims (1)

第１導電型を有する第１半導体層と、
この第１半導体層の表層部に埋設され、前記第１導電型とは異なる第２導電型を有する第２半導体層と、
この第２半導体層の表層部に埋設され、前記第１導電型を有する第３半導体層と、
前記第２半導体層と前記第３半導体層とを接続する配線とを含むことを特徴とする、受光素子。

A first semiconductor layer having a first conductivity type;
A second semiconductor layer embedded in a surface layer portion of the first semiconductor layer and having a second conductivity type different from the first conductivity type;
A third semiconductor layer embedded in a surface layer portion of the second semiconductor layer and having the first conductivity type;
A light receiving element comprising: a wiring connecting the second semiconductor layer and the third semiconductor layer.

JP2006134094A 2006-05-12 2006-05-12 Light receiving element Pending JP2007305868A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8610133B2 (en) 2010-10-14 2013-12-17 Rohm Co., Ltd. Photodetection device
US9568361B2 (en) 2013-09-26 2017-02-14 Rohm Co., Ltd. Optical sensor device
US9831373B2 (en) 2012-09-11 2017-11-28 Sharp Kabushiki Kaisha Illuminance sensor, proximity sensor, and display device including the sensor

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5546557A (en) * 1978-09-28 1980-04-01 Sharp Corp Light semiconductor device
JPS5585082A (en) * 1978-12-20 1980-06-26 Sharp Corp Optical semiconductor apparatus
JP2000077702A (en) * 1998-08-31 2000-03-14 Oki Electric Ind Co Ltd Semiconductor light receiving element, method of manufacturing semiconductor light receiving element, and light receiving element module

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5546557A (en) * 1978-09-28 1980-04-01 Sharp Corp Light semiconductor device
JPS5585082A (en) * 1978-12-20 1980-06-26 Sharp Corp Optical semiconductor apparatus
JP2000077702A (en) * 1998-08-31 2000-03-14 Oki Electric Ind Co Ltd Semiconductor light receiving element, method of manufacturing semiconductor light receiving element, and light receiving element module

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8610133B2 (en) 2010-10-14 2013-12-17 Rohm Co., Ltd. Photodetection device
US8975645B2 (en) 2010-10-14 2015-03-10 Rohm Co., Ltd. Optical filter
US9831373B2 (en) 2012-09-11 2017-11-28 Sharp Kabushiki Kaisha Illuminance sensor, proximity sensor, and display device including the sensor
US9568361B2 (en) 2013-09-26 2017-02-14 Rohm Co., Ltd. Optical sensor device

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