JPH0231509B2 - - Google Patents
Info
- Publication number
- JPH0231509B2 JPH0231509B2 JP56084000A JP8400081A JPH0231509B2 JP H0231509 B2 JPH0231509 B2 JP H0231509B2 JP 56084000 A JP56084000 A JP 56084000A JP 8400081 A JP8400081 A JP 8400081A JP H0231509 B2 JPH0231509 B2 JP H0231509B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- layer
- semiconductor layer
- type
- guard ring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000004065 semiconductor Substances 0.000 claims description 23
- 239000012535 impurity Substances 0.000 description 8
- 238000000098 azimuthal photoelectron diffraction Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 230000015556 catabolic process Effects 0.000 description 3
- 230000031700 light absorption Effects 0.000 description 3
- 206010034972 Photosensitivity reaction Diseases 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000005468 ion implantation Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000036211 photosensitivity Effects 0.000 description 2
- 108091006149 Electron carriers Proteins 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
- H01L31/10—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors
- H01L31/101—Devices sensitive to infrared, visible or ultraviolet radiation
- H01L31/102—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier
- H01L31/107—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier the potential barrier working in avalanche mode, e.g. avalanche photodiodes
- H01L31/1075—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier the potential barrier working in avalanche mode, e.g. avalanche photodiodes in which the active layers, e.g. absorption or multiplication layers, form an heterostructure, e.g. SAM structure
Landscapes
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Radiation Pyrometers (AREA)
- Light Receiving Elements (AREA)
Description
【発明の詳細な説明】 本発明は受光素子に関する。[Detailed description of the invention] The present invention relates to a light receiving element.
1μｍ帯光通信用受光素子は、Ge−APD（アパ
ランシエ・フオト・ダイオード）或いはInP系
APDが用いられる。Ga−APDは実用化されてい
るが、暗電流が高い、光波長1.55μｍよりも長波
長で全く光感度がなくなると言う欠点がある。そ
の為、現在ではInP系APDの開発が盛んである。
この理由はInP半導体はGe半導体に較べて、ダイ
オード暗電流密度が約５桁小さいと言う点と、
InPと格子整合したInGaAsP半導体は光波長1.7μ
ｍまで光感光を有すると言う点にある。 The light receiving element for 1 μm band optical communication is Ge-APD (apalance photo diode) or InP type.
APD is used. Although Ga-APDs have been put into practical use, they have the drawbacks of high dark current and complete lack of photosensitivity at wavelengths longer than 1.55 μm. Therefore, the development of InP-based APDs is currently active.
The reason for this is that the diode dark current density of InP semiconductors is about 5 orders of magnitude lower than that of Ge semiconductors.
InGaAsP semiconductor lattice-matched to InP has a light wavelength of 1.7μ.
The point is that it has photosensitivity up to m.
InP系APDの基本構造は第１図に示す如くであ
る。即ち上層から順番にｎ型InP層（ウインドー
層１、ｎ型InGaAsP層（光吸収層）２、ｎ型InP
層（バツフアー層）３、n+型InP層（基板）４で
ある。これらの各層がLPE（液相エピタキシヤ
ル）成長で作成される。この後、ウインドー層１
にダイオードが形成される。その典型的な構造を
第２図に示す。ウインドー層１へのＰ層形成は、
熱拡散法或いはイオン注入法でＰ型不純物を添加
することによつて行なわれる。不純物はCdが最
も一般的である。第２図で５の領域は受光部の
P+領域、６の領域はガードリング部のＰ領域で
ある。 The basic structure of an InP-based APD is shown in Figure 1. That is, in order from the top, the n-type InP layer (window layer 1, n-type InGaAsP layer (light absorption layer) 2, n-type InP
They are a layer (buffer layer) 3 and an n + type InP layer (substrate) 4. Each of these layers is created by LPE (liquid phase epitaxial) growth. After this, window layer 1
A diode is formed. Its typical structure is shown in FIG. Formation of P layer on window layer 1 is as follows:
This is done by adding P-type impurities by thermal diffusion or ion implantation. The most common impurity is Cd. In Figure 2, area 5 is the light receiving area.
The P + region and the region 6 are the P regions of the guard ring portion.
現在のウインドー層１の層厚は数μｍである。
LPE成長技術から見て、ウインドー層厚を10μｍ
以上とすることは困難であるし、仮りにこれが可
能となつても、４元層に電界が発生するように素
子として動作させるためにウインドー層１の電子
キヤリア濃度を低減させることは不純物制御技術
上困難である。従つて数μｍの層厚のウインドー
層１に受光部５とガードリング部６を設けること
になるが、この点に関して現在問題がある。これ
について次に説明する。 The current layer thickness of the window layer 1 is several μm.
From the perspective of LPE growth technology, the window layer thickness is 10μm.
It is difficult to achieve the above, and even if it were possible, impurity control technology would be required to reduce the electron carrier concentration in the window layer 1 in order to operate it as a device so that an electric field is generated in the quaternary layer. It is difficult to do so. Therefore, the light receiving section 5 and the guard ring section 6 are provided in the window layer 1 having a layer thickness of several μm, but there is currently a problem in this regard. This will be explained next.
素子設計上、意図するところは、第２図に於
て、受光部５とウインドー層１が接する接合部を
片側接合として、ガードリング部６とウインドー
層１とが接する接合部を両側接合とすることであ
る。これによつて前者のブレークダウン電圧VB
１、後者のブレークダウン電圧VB2との間にVB1＜
VB2の関係が成り立つ。且つVB1とVB2との差が大
きい。ところが上記のことを実現することはプロ
セス上から見て容易ではない。即ち、選択ドーピ
ングを行なうに当つて、受光部５に於ては深さ方
向に急勾配の不純物布を得させて、ガードリング
部６に於ては深さ方向にゆるやかな勾配の不純物
分布を得させることは容易ではない。 In terms of element design, the intention in FIG. 2 is that the joint where the light receiving section 5 and the window layer 1 are in contact is a one-sided joint, and the joint where the guard ring part 6 and the window layer 1 are in contact is a double-sided joint. That's true. This reduces the breakdown voltage of the former V B
1 , between the latter breakdown voltage V B2 and V B1 <
The relationship V B2 holds true. Moreover, the difference between V B1 and V B2 is large. However, achieving the above is not easy from a process standpoint. That is, when performing selective doping, an impurity distribution with a steep gradient in the depth direction is obtained in the light receiving section 5, and an impurity distribution with a gentle gradient in the depth direction is obtained in the guard ring section 6. It is not easy to make a profit.
本発明の目的は、従来のこのような欠点を解決
し、ガードリングの効果が充分に期待される構造
の受光素子を提供することにある。 SUMMARY OF THE INVENTION An object of the present invention is to solve these conventional drawbacks and provide a light-receiving element having a structure in which the effect of the guard ring can be fully expected.
このような本発明の特徴は、−族２元半導
体層表面に受光部とガードリングが形成されてな
る受光素子において、該−族２元半導体層内
に、これより禁制帯幅が狭くかつキヤリア濃度の
高い−族多元半導体層を、該受光部の直下の
該受光部とは離隔された領域に選択的に設けたこ
とにある。 Such a feature of the present invention is that in a light-receiving element in which a light-receiving portion and a guard ring are formed on the surface of a - group binary semiconductor layer, there is a bandgap narrower and a carrier in the - group binary semiconductor layer. The present invention is based on selectively providing a high-concentration - group multi-component semiconductor layer in a region immediately below the light-receiving section and separated from the light-receiving section.
以下本発明の一実施例を、その製造工程順を追
つて説明する。 An embodiment of the present invention will be described below in the order of its manufacturing steps.
まず、第３図ａのように、n+型InP基板４上に
ｎ型InPバツフア層３をLPE成長して更にｎ型
InGaAsP層２をLPE成長する。この時点で一旦、
半導体を成長炉から取り出す。そして、第３図ｂ
ように素子形状から見て典型的には直径100μｍ
程度の受光部に相当するInGaAsP２の部分を残
して、それ以外のInGaAsPをエツチング処理に
よつて除去される。次にこの半導体を再び成長炉
内部に納めて、LPE成長を継続して第３図ｃの
如くにウインドー層１を形成する。次にこの半導
体に熱拡散法或いはイオン注入法によつてＰ型不
純物の選択ドーピングを施し、第３図ｄに示す如
くに受光部５とガードリング部６を形成する。こ
の際に、受光部５の大きさは、光吸収層２を上方
から充分に被うことが出来るように光吸収相２の
大きさよりも広く形成する。そして、ガードリン
グ部６は受光部５の外周部に形成される。 First, as shown in Figure 3a, an n - type InP buffer layer 3 is grown by LPE on an n
InGaAsP layer 2 is grown by LPE. At this point, once
Take out the semiconductor from the growth furnace. And Figure 3b
Considering the element shape, the diameter is typically 100 μm.
The remaining InGaAsP is removed by etching, leaving a portion of InGaAsP2 corresponding to the light-receiving portion of about 100 psi. Next, this semiconductor is placed inside the growth furnace again and LPE growth is continued to form the window layer 1 as shown in FIG. 3c. Next, this semiconductor is selectively doped with P-type impurities by thermal diffusion or ion implantation to form a light receiving portion 5 and a guard ring portion 6 as shown in FIG. 3d. At this time, the size of the light-receiving part 5 is made larger than the size of the light-absorbing layer 2 so that it can sufficiently cover the light-absorbing layer 2 from above. The guard ring portion 6 is formed on the outer periphery of the light receiving portion 5.
第３図に於て、ｎ型InP層１，３は、通常不純
物濃度を低減させた公称不純物無添加の成長層で
ある。この２層の電子濃度を各々n1、n3とする。
他方、光吸収層２も同様に通常、不純物無添加の
成長層でありこの電子濃度をn2とする。各層の電
子濃度の関係に関して次の条件が成立することが
必要である。 In FIG. 3, the n-type InP layers 1 and 3 are nominally impurity-free growth layers with reduced impurity concentrations. Let the electron concentrations of these two layers be n 1 and n 3 , respectively.
On the other hand, the light absorption layer 2 is also normally a grown layer without the addition of impurities, and its electron concentration is set to n2 . Regarding the relationship between the electron concentrations of each layer, it is necessary that the following conditions hold true.
n1、n3＜n2
上記の条件が成立すると、受光部５とウインド
ー層１、ガードリング部６とウインドー層１の接
合が、各々明確に片側接合、両側接合になつてい
なくても、第３図ｄの光吸収層２の上部の受光部
５とウインドー層１の接合部でのみ（高逆電圧印
加時に）優先的にブレークダウンを発生する。従
つてガードリング部６は結果的にガードリングと
しての役割を充分に果すことになる。この理由は
n1、n3＜n2である為に光吸収層２の上方の受光部
５−ウインドー層１間の接合部で（高逆電圧印加
時に）優先的に高電界に達するからである。 n 1 , n 3 < n 2 When the above conditions are met, even if the bonding between the light receiving section 5 and the window layer 1, and the guard ring section 6 and the window layer 1 are not clearly one-sided bonding or both-side bonding, Breakdown occurs preferentially (when a high reverse voltage is applied) only at the junction between the light-receiving section 5 on the upper part of the light-absorbing layer 2 and the window layer 1 in FIG. 3d. Therefore, the guard ring portion 6 ultimately fulfills its role as a guard ring. The reason for this is
This is because since n 1 , n 3 <n 2 , a high electric field is preferentially reached at the junction between the light receiving section 5 and the window layer 1 above the light absorption layer 2 (when a high reverse voltage is applied).
さらに本発明の構造は雑音レベルを低減させる
結果を得る点でも非常に有効である。以下にこの
点を説明する。一般的に、第４図に示した如く、
Ｐ型領域７とｎ型領域８を有するPn接合ダイオ
ードに於て逆方向電圧加時に発生する暗電流は表
面暗電流Isと半導体内部から発生するバルク暗電
流Ibに類別できる。通常Isはパシベーシヨン技術
によつて改善される。他方Ibは半導体の種類と品
質に依存する。InP半導体とInGaAsP半導体を比
較した場合、後者がより狭い禁制帯幅を持つ為に
本質的により高い暗電流を発生することは知られ
ている。従つて第５図のInP(3)／InGaAsP(2)／
InP(1)多層半導体に於て、InGaAsPの４元領域２
を経由するパルク暗電流Ibqを減らして、４元領
域を経由しないパルク暗電流Ibbの割合を増して
やる方が暗電流低減の為には良いことが判かる。
ただし、ここで
Ib＝Ibq＋Ibb
とする。故に第５図ｂに示したようなInP１中に
InGaAsP２を埋込んだ構造の且つInGaAsP２の
存在を必要最小限に小さく抑えることが良いこと
が判る。 Furthermore, the structure of the present invention is also very effective in obtaining results that reduce the noise level. This point will be explained below. Generally, as shown in Figure 4,
The dark current generated when a reverse voltage is applied in a Pn junction diode having a P-type region 7 and an n-type region 8 can be classified into a surface dark current Is and a bulk dark current Ib generated from inside the semiconductor. Usually Is is improved by passivation techniques. On the other hand, Ib depends on the type and quality of the semiconductor. When comparing InP and InGaAsP semiconductors, it is known that the latter inherently generates a higher dark current due to its narrower bandgap. Therefore, InP(3)/InGaAsP(2)/ in Figure 5
In InP(1) multilayer semiconductor, InGaAsP quaternary region 2
It can be seen that it is better to reduce the dark current by reducing the pulse dark current Ibq that passes through the quaternary region and increasing the proportion of the pulse dark current Ibb that does not pass through the quaternary region.
However, here Ib=Ibq+Ibb. Therefore, in InP1 as shown in Figure 5b,
It can be seen that it is better to have a structure in which InGaAsP2 is embedded and to suppress the presence of InGaAsP2 to the necessary minimum.
本実施例の説明は、LPE成長したInP／
InGaAsP／InP半導体について行なつたが、VPE
（気相エピタキシヤル）成長した半導体について
も同じ構造が形成できれば、同じ効果が得られ
る。更に−半導体に於て格子整合した任意の
材料の組合せを用いても成立する。更にPn型を
反転させてＰ型半導体にｎ型領域を形成して同様
の構造を作成することもできる。 The description of this example is based on LPE-grown InP/
Although we conducted research on InGaAsP/InP semiconductors, VPE
(Vapor phase epitaxial) If the same structure can be formed for a grown semiconductor, the same effect can be obtained. Furthermore, it is also possible to use any combination of lattice-matched materials in semiconductors. Furthermore, a similar structure can be created by inverting the Pn type and forming an n type region in a P type semiconductor.
以上説明したように、本発明によれば、ガード
リング効果を充分に発揮し、しかも雑音レベルの
低い受光素子が実現される。 As described above, according to the present invention, a light receiving element that fully exhibits the guard ring effect and has a low noise level can be realized.
第１図および第２図はそれぞれ従来の受光素子
を示す断面図、第３図は本発明の一実施例を説明
するための製造工程順断面図、第４図および第５
図は本発明の効果を説明するための断面図であ
る。
１：−族２元半導体層（ウインドー層）、
２：−族多元半導体層（InGaAsP層）、５：
受光部、６：ガードリング部。
1 and 2 are cross-sectional views showing a conventional light-receiving element, FIG. 3 is a cross-sectional view in the order of manufacturing steps for explaining an embodiment of the present invention, and FIGS. 4 and 5
The figure is a sectional view for explaining the effects of the present invention. 1: - group binary semiconductor layer (window layer),
2: - group multi-component semiconductor layer (InGaAsP layer), 5:
Light receiving part, 6: Guard ring part.
Claims (1)
電型の受光部とガードリングが形成されてなる受
光素子において、 該−族２元半導体層より禁制帯幅が狭くか
つキヤリア濃度の高い一導電型−族多元半導
体層を、 該受光部直下であつて、且つそのPN接合と離
隔した領域に、周囲が該一導電型−族２元半
導体層に包含された状態の島状に設けたことを特
徴とする受光素子。[Scope of Claims] 1. A light-receiving element in which a light-receiving portion and a guard ring of an opposite conductivity type are formed on the surface of a -group binary semiconductor layer of one conductivity type, which has a narrower forbidden band width than the -group binary semiconductor layer; A one-conductivity type - group multi-component semiconductor layer with a high carrier concentration is placed in a region immediately below the light-receiving section and separated from the PN junction, the periphery of which is surrounded by the one-conductivity-type - group binary semiconductor layer. A light receiving element characterized by being arranged in an island shape.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56084000A JPS57198668A (en) | 1981-06-01 | 1981-06-01 | Light receiving element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56084000A JPS57198668A (en) | 1981-06-01 | 1981-06-01 | Light receiving element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57198668A JPS57198668A (en) | 1982-12-06 |
| JPH0231509B2 true JPH0231509B2 (en) | 1990-07-13 |
Family
ID=13818254
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56084000A Granted JPS57198668A (en) | 1981-06-01 | 1981-06-01 | Light receiving element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57198668A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6285832A (en) * | 1985-10-11 | 1987-04-20 | Mitsubishi Cable Ind Ltd | Optical type thermometer |
| JPS63224252A (en) * | 1987-02-06 | 1988-09-19 | シーメンス、アクチエンゲゼルシヤフト | Waveguide-photodiode array |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51140587A (en) * | 1975-05-16 | 1976-12-03 | Thomson Csf | Avalanche photodiode |
| JPS5513990A (en) * | 1978-07-18 | 1980-01-31 | Nec Corp | Semiconductor device |
| JPS5572084A (en) * | 1978-11-27 | 1980-05-30 | Nippon Telegr & Teleph Corp <Ntt> | Semiconductor photo-detector |
-
1981
- 1981-06-01 JP JP56084000A patent/JPS57198668A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51140587A (en) * | 1975-05-16 | 1976-12-03 | Thomson Csf | Avalanche photodiode |
| JPS5513990A (en) * | 1978-07-18 | 1980-01-31 | Nec Corp | Semiconductor device |
| JPS5572084A (en) * | 1978-11-27 | 1980-05-30 | Nippon Telegr & Teleph Corp <Ntt> | Semiconductor photo-detector |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57198668A (en) | 1982-12-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4442444A (en) | Avalanche photodiodes | |
| US4651187A (en) | Avalanche photodiode | |
| EP0156156A1 (en) | Avalanche photodiodes | |
| JP2010147158A (en) | Semiconductor light-receiving element and method of manufacturing the same | |
| JPH02202071A (en) | Semiconductor photodetector and manufacture thereof | |
| US5942771A (en) | Semiconductor photodetector | |
| JPH0231509B2 (en) | ||
| JPH07118548B2 (en) | III-V group compound semiconductor PIN photo diode | |
| GB2157490A (en) | Avalanche photodetector | |
| JPS5938748B2 (en) | semiconductor photodetector | |
| JPS6138872B2 (en) | ||
| JPS6398158A (en) | Photodiode | |
| JP4601129B2 (en) | Semiconductor light receiving element manufacturing method | |
| JP3055030B2 (en) | Manufacturing method of avalanche photodiode | |
| JP2658013B2 (en) | Manufacturing method of semiconductor light receiving element | |
| JPH0157509B2 (en) | ||
| JPS6146076B2 (en) | ||
| JP2711055B2 (en) | Semiconductor photodetector and method of manufacturing the same | |
| JPS6259905B2 (en) | ||
| JPS6086877A (en) | Optical semiconductor device | |
| JPH0410233B2 (en) | ||
| JPS6229917B2 (en) | ||
| JPS58170073A (en) | Semiconductor device | |
| JPS6138871B2 (en) | ||
| JPH02228080A (en) | Semiconductor photodetector |