CN109285913B - Mesa photoelectric detector with low surface leakage current and manufacturing method thereof - Google Patents
Mesa photoelectric detector with low surface leakage current and manufacturing method thereof Download PDFInfo
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- 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
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- H01L31/02—Details
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- H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
- H01L31/184—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof the active layers comprising only AIIIBV compounds, e.g. GaAs, InP
- H01L31/1844—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof the active layers comprising only AIIIBV compounds, e.g. GaAs, InP comprising ternary or quaternary compounds, e.g. Ga Al As, In Ga As P
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- H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
- H01L31/186—Particular post-treatment for the devices, e.g. annealing, impurity gettering, short-circuit elimination, recrystallisation
- H01L31/1868—Passivation
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Abstract
The invention belongs to the technical field of detector chip manufacturing, in particular to a mesa photoelectric detector with low surface leakage current and a manufacturing method thereof, wherein the method comprises the steps of depositing a mask on the top layer of an epitaxial wafer and forming a mesa etching window through a photoetching process; etching the epitaxial wafer into an epitaxial table top by adopting wet etching, carrying out surface chemical cleaning, removing residual products of the wet etching reaction and the like; the surface of the side wall of the epitaxial table top is passivated by adopting a vulcanization process to reduce the surface state of the epitaxial table top; treating the surface of the side wall by using hexamethyldisilazane, and coating benzocyclobutene to form a protective layer; under the protection of nitrogen atmosphere, adopting distributed heating and curing; etching part of the protective layer to expose the top of the table top, depositing a metal film on the upper surface of the contact layer according to an evaporation or sputtering mode, and stripping to form a P-type electrode; thinning the back surface, and depositing an antireflection film on the back surface; and (5) manufacturing the N electrode by adopting stripping with glue. The invention solves the problem of difficult side wall surface passivation of the mesa device caused by wet etching.
Description
Technical Field
The invention belongs to the technical field of detector chip manufacturing, and particularly relates to a mesa photoelectric detector with low surface leakage current and a manufacturing method thereof.
Background
Semiconductor device performance is severely affected by semiconductor surface effects. In the mesa process, the periodicity of the crystal lattice is damaged, dangling bonds are generated on the surface of the outermost atom, and the dangling bonds can trap electrons or holes in a body to form a surface depletion layer to increase the surface state. And other defects and impurity oxides exist on the surface of the outermost layer, and due to the factors, impurity energy levels are introduced into forbidden bands to generate recombination centers, so that the surface recombination rate is increased, the surface leakage current of the device is increased, and the electrical performance of the device is seriously influenced.
The mesa type photoelectric detector is widely applied to high-speed electronic devices and photoelectronic devices, is usually in a certain bias state when working, and can aggravate the reduction of minority carrier lifetime of a surface recombination center and increase surface leakage current under a surface high electric field. Thus, sidewall passivation of mesa photodetectors is a difficult problem. The prior process method for reducing the surface leakage current of the mesa device comprises the following steps:
(1) after the mesa is etched by a wet method, the surface state is reduced by vulcanization, and then an inorganic passivation film (silicon nitride or aluminum oxide) is used for protecting a vulcanization layer. The plasma bombardment and the high growth temperature (generally more than 250 ℃) introduced by the process can damage the vulcanized layer, deteriorate the passivation effect and increase the surface leakage current.
(2) The manufacturing method (application number 201310013303.2) of the photoelectric detector chip for reducing the dark current based on the plasma-free process avoids the damage of the plasma to the corrosion surface, and adopts an organic passivation film (benzocyclobutene BCB) to replace a chemical vapor deposition passivation process, so that the dark current is reduced. However, before the BCB passivation, surface vulcanization treatment is not performed, and the surface of the side wall is corroded to easily generate a high surface state, so that the passivation effect is deteriorated.
Disclosure of Invention
In view of the above, the present invention provides a mesa photodetector with low surface leakage current and a method for fabricating the same. The problem of difficult side wall surface passivation of a mesa device caused by wet etching is solved. After the mesa formation process, the etch material surface states are first effectively reduced by sulfidation, with dark current levels comparable to planar devices. And then, benzocyclobutene (BCB) which can not damage the vulcanized layer is adopted as a protective layer to play a role in stabilizing the vulcanized layer for a long time. Under the bias voltage, the component from the surface leakage current in the dark current of the photoelectric detector is also very small, which is mainly generated from the body dark current, and the manufacturing method of the mesa-type photoelectric detector with low surface leakage current is provided.
The manufacturing method of the mesa photoelectric detector with low surface leakage current comprises the following steps:
s1, depositing a mask on the top layer of the epitaxial wafer, and forming a mesa etching window through a photoetching process;
s2, etching the epitaxial wafer into an epitaxial table top by adopting wet etching, carrying out surface chemical cleaning, and removing residual products, surface oxides and impurity contaminants of the wet etching reaction;
s3, passivating the side wall surface of the epitaxial table top by adopting a vulcanization process to reduce the surface state of the epitaxial table top;
s4, treating the surface of the side wall by using hexamethyldisilazane, and coating benzocyclobutene to form a protective layer; under the protection of nitrogen atmosphere, adopting distributed heating and curing;
s5, etching part of the protective layer to expose the top of the epitaxial table top, depositing a metal film on the upper surface of the contact layer according to an evaporation or sputtering mode, and forming a P-type electrode after stripping;
s6, thinning the back of the epitaxial table top, and depositing an antireflection film on the back;
and S7, manufacturing the N-type electrode by adopting tape stripping.
Further, the step S1 specifically includes: and growing a layer of composite dielectric film on the epitaxial wafer by adopting plasma enhanced chemical vapor deposition, spin-coating photoresist by a photoetching process, after exposure and development, corroding the composite dielectric film by using hydrogen fluoride, cleaning the composite dielectric film, and leaving a mesa etching mask so as to determine a mesa etching window.
Further, in step S2, etching the epitaxial wafer according to the mesa etching window, and etching away part of the buffer layer, the absorption layer, the graded layer, the charge layer, the multiplication layer, and the contact layer in the epitaxial wafer; thereby forming an epitaxial mesa; for convenience of description, the epitaxial mesa of the present invention is also referred to as a mesa.
Further, the raw material used for the sulfidation process in the step S3 includes (NH)4)2S、(NH4)2Sx、H2Any one or more of S, NaS and ZnS, and the passivation mode comprises wet chemical reaction and magnetron sputtering.
Preferably, the step S4 of treating the surface of the sidewall with hexamethyldisilazane includes applying vapor phase coating, solution immersion, spin coating, or the like.
The mesa-type photoelectric detector with low surface leakage current comprises an epitaxial mesa, wherein an antireflection film is deposited on the lower surface of the epitaxial mesa, and an N electrode is formed on the antireflection film; coating a protective layer on the upper surface of the epitaxial table top; depositing a metal film above the protective layer to form a P electrode; the epitaxial table-board comprises a substrate layer, and a buffer layer, an absorption layer, a gradient layer, a charge layer, a multiplication layer and a contact layer which are sequentially stacked on the substrate; the buffer layer, the absorption layer, the gradient layer, the charge layer, the multiplication layer, the contact layer and the P-type electrode are all concentric and the radiuses of the buffer layer, the absorption layer, the gradient layer, the charge layer, the multiplication layer, the contact layer and the P-type electrode are sequentially reduced, so that the side wall of the formed table top is an inclined surface.
Preferably, the substrate layer, the buffer layer, the charge layer and the multiplication layer are all made of InP, the absorption layer is made of InGaAs, and the graded layer and the contact layer are made of InGaAsP.
Preferably, the thickness of the buffer layer is 0.1-1 μm; the thickness of the absorption layer is 1-3 mu m; the thickness of the gradual change layer is 0.01-0.1 μm, and the thickness of the charge layer is 0.1-0.5 μm; the thickness of the multiplication layer and the contact layer is 0.05-0.1 μm.
Preferably, the doping concentration of the buffer layer is less than 8 × 1017cm-3(ii) a The doping concentration of the graded layer is less than or equal to 1 multiplied by 1017cm-3(ii) a The doping concentration of the charge layer is 5X 1016～5×1017cm-3(ii) a The doping concentration of the multiplication layer and the doping concentration of the contact layer are both more than 1 multiplied by 1019cm-3。
Compared with the prior art, the invention has the following advantages and positive effects:
(1) and the preferential selection of the etching solution has isotropy to the etching of different materials, so that the side wall of the epitaxial table top has no material interface layering, and the continuous and smooth material interface is beneficial to the passivation of the table top. Meanwhile, in the wet etching process, the residue of a reaction product is easy to remove and cannot cover or adhere to the side wall to hinder chemical reaction.
(2) And a vulcanization passivation layer is generated on the surface of the material by adopting a vulcanization reaction, so that the surface state of the material can be effectively reduced. And the mode that the vulcanization layer combines together with benzocyclobutene (BCB) is as passivation layer and protection isolation layer respectively, can show the long-term stability that has promoted the vulcanization layer.
(3) The surface vulcanization passivation layer is protected by adopting benzocyclobutene (BCB) to replace an inorganic passivation film (Si3N4 and SiO2), and the method has obvious beneficial effects. Firstly, the surface bombardment of the vulcanized layer by high-energy plasma in a Chemical Vapor Deposition (CVD) process or the decomposition of the vulcanized layer under a high-temperature growth condition is avoided, so that the passivation effect is prevented from being degraded. Second, the interfacial contact of the vulcanizate with benzocyclobutene (BCB) is enhanced by improved surface adhesion by Hexamethyldisilazane (HMDS). Finally, benzocyclobutene (BCB) curing does not release gas as does polyimide curing reactions, resulting in loose pores. The volatile matter is not simply evaporated to be changed into solid during curing, but the molecular group structure is changed by chemical reaction during thermal curing, no gas is generated during the whole reaction process, and the surface of the vulcanized layer is protected more favorably.
(4) The mesa photoelectric detector prepared by the method has lower dark current under the external bias voltage, which shows that the mesa photoelectric detector has a good surface state. Meanwhile, the magnitude of dark current is in direct proportion to the area, the main component of the surface of the passivation solution comes from the body dark current, the leakage current component is very small, and the method has a good passivation effect.
Drawings
FIG. 1 is a schematic view of an epitaxial material structure;
FIG. 2 is a schematic diagram of a process for etching a mesa;
FIG. 3 is a schematic view of a surface sulfidation passivation and BCB protection layer process;
FIG. 4 is a schematic view of a backside process of a chip;
in the figure, the organic electroluminescent device comprises a substrate layer 1, a buffer layer 2, a buffer layer 3, an absorption layer 4, a gradient layer 5, a charge layer 6, a multiplication layer 7, a contact layer 8, a composite dielectric film 9, a P-type electrode 10, a protective layer 11 and an antireflection film.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more clearly and completely apparent, the technical solutions in the embodiments of the present invention are described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
Example 1
The manufacturing method of the mesa photoelectric detector with low surface leakage current can be realized according to the following scheme:
(1) defining a mesa etching window, depositing a mask on the top layer of the epitaxial wafer, and opening the mesa etching window through a photoetching process;
(2) and etching the epitaxial wafer into a platform by adopting wet etching, and then carrying out surface chemical cleaning to remove residual products, surface oxides and surface impurities and contaminants of the wet etching reaction.
(3) And the surface of the side wall is passivated by adopting a vulcanization process to treat, so that the surface state of the side wall is reduced.
(4) The surface was treated with Hexamethyldisilazane (HMDS) to enhance adhesion, and coated with BCB. Under the protection of N2 atmosphere, the curing is carried out by adopting distributed temperature rise.
(5) Defining P electrode, depositing metal film by evaporation or sputtering, and stripping to form P electrode pattern.
(6) And thinning the back surface, and depositing an antireflection film on the back surface.
(7) And defining the N electrode, and manufacturing the N electrode by adopting tape stripping to finish the process manufacturing of the photoelectric detector chip.
The requirement of the etching solution in the step (2) is as follows: the corrosion rate of the solution to various materials to be corroded is basically consistent, the material interface is continuous and smooth, the solution corrosion rate is stable and controllable, and reaction residual products are easy to remove.
The surface chemical cleaning in the step (2) comprises an organic solvent and a weakly acidic solution, such as: any one or more of ethanol, acetone, glacial acetic acid, citric acid, a mixed solution of H2SO4 and hydrogen peroxide, and a mixed solution of hydrofluoric acid and ammonium fluoride.
The raw materials of the vulcanization process in the step (3) comprise: (NH)4)2S、(NH4)2Sx、H2One or more of S, NaS and ZnS, and the sulfur passivation mode comprises wet chemical reaction and magnetron sputtering.
The surface treatment mode of Hexamethyldisilazane (HMDS) in the step (4) comprises the following steps: vapor phase coating, solution immersion, spin coating, and the like. After coating, baking at a certain temperature (90-120 ℃) for about 1-5 min.
The BCB in the step (4) is non-photosensitive, and may also be photosensitive BCB. Has the characteristics of good electrical insulation performance, thermal stability, good adhesion, good moisture absorption resistance, small stress and the like. The BCB curing temperature is relatively low, the thermosetting is divided into 2 steps of reaction processes, and after the heat applied to molecules reaches ring-opening energy, the cyclobutene four rings generate ring-opening reaction to generate an intermediate. Then the ring-opening product undergoes self-addition polymerization through thermal reaction to form a high-molecular polymer matrix, so that the BCB is cured.
Example 2
In this embodiment, on the basis of embodiment 1, the avalanche photodiode mesa fabrication process is taken as a column, and the structure of the epitaxial wafer includes as shown in fig. 1: an N-type InP substrate 1; an N-type InP buffer layer 2 with a thickness of 0.1-1 μm and a doping concentration of less than 8 × 1017cm-3(ii) a A non-doped InGaAs absorption layer 3 with the thickness of 1-3 μm; an N-type InGaAsP graded layer 4 with a thickness of 0.01-0.1 μm and a doping concentration of 1 × 10 or less17cm-3(ii) a An N-type InP charge layer 5 with a thickness of 0.1-0.5 μm and a doping concentration of 5 × 1016～5×1017cm-3(ii) a An InP multiplication layer 6 and a P type-InGaAsP contact layer 7 with a thickness of 0.05-0.1 μm and a doping concentration of more than 1 × 1019cm-3。
The preparation process comprises the following steps:
(11) growing a layer of SiNx/SiO by Plasma Enhanced Chemical Vapor Deposition (PECVD)2the/SiNx composite dielectric film 8 is coated with photoresist by a photoetching processAfter exposure and development, the dielectric film is etched off by using HF, the substrate is cleaned, and a mesa etching mask is left. Bromine water solution (HBr, H) for single-chip wet etching equipment2O2And H2O) performing mesa formation etching, and etching the N-type substrate to the etching depth at the temperature of 20 ℃ for 4min, as shown in fig. 2.
(22) Cleaning the surface, washing with deionized water for 5min, sequentially boiling with acetone and ethanol for 3min, soaking in HF acid solution at room temperature for 30sec to remove organic substances and oxides on the surface, washing with water for 5min, and oven drying.
(33) And (3) surface vulcanization passivation, namely placing the epitaxial wafer into an amine sulfide solution at 60 ℃, soaking for 30min, and generating a vulcanized layer on the surface of the material. Taking out, washing with deionized water for 5min, and oven drying in nitrogen gas cylinder.
(44) Immersing in HMDS solution for 3min, and baking at 95 deg.C for 5 min.
(55) AP3000 was applied at 4000RPM/30Sec followed by BCB overcoat 10 at 4000RPM/30 Sec. Under the protection of nitrogen (wherein the content of O2 is less than 100ppm), according to a temperature rising curve: keeping the temperature at 50 deg.C for 5min, then keeping the temperature at 50 deg.C for 15min, and keeping the temperature at 260 deg.C for 60 min. The P-type electrode pattern was produced by exposure and development using 5200NJ photoresist. Then plasma gas CF 4: o2 ═ 90:60ml/min, and BCB protective layer 10 was etched away at 150W power to expose the top layer material of the mesa.
(66) A P-type electrode 9 was fabricated by a lift-off method by evaporating a Ti/Pt/Au metal film at 80 ℃ using an electron beam evaporation stage, as shown in FIG. 3.
(77) And thinning the back of the table board, growing a layer of SiNx as an antireflection film 11, photoetching to form an N electrode pattern, corroding the antireflection film by hydrofluoric acid, and cleaning. And (3) evaporating a Cr/Au layer, and making an N electrode by photoetching to finish the process, as shown in figure 4.
The above-mentioned embodiments, which further illustrate the objects, technical solutions and advantages of the present invention, should be understood that the above-mentioned embodiments are only preferred embodiments of the present invention, and should not be construed as limiting the present invention, and any modifications, equivalents, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (9)
1. A mesa-type photodetector with low surface leakage current is characterized by comprising an epitaxial mesa, wherein an antireflection film is deposited on the lower surface of the epitaxial mesa, and an N electrode is formed on the antireflection film; adopting a vulcanization process to treat the epitaxial table top and passivate the epitaxial table top; coating hexamethyldisilazane on the surface of the side wall of the passivated epitaxial mesa, coating benzocyclobutene and forming a protective layer; depositing a metal film above the protective layer to form a P electrode; the epitaxial table-board comprises a substrate layer, and a buffer layer, an absorption layer, a gradient layer, a charge layer, a multiplication layer and a contact layer which are sequentially stacked on the substrate; the buffer layer, the absorption layer, the gradient layer, the charge layer, the multiplication layer, the contact layer and the P-type electrode are all concentric and the radiuses of the buffer layer, the absorption layer, the gradient layer, the charge layer, the multiplication layer, the contact layer and the P-type electrode are sequentially reduced, so that the side wall of the formed table top is an inclined surface.
2. The mesa photodetector of claim 1, wherein the substrate layer, the buffer layer, the charge layer and the multiplication layer are all made of InP, the absorption layer is InGaAs, and the graded layer and the contact layer are made of InGaAsP.
3. The mesa photodetector of claim 1, wherein the buffer layer has a thickness of 0.1 to 1 μm; the thickness of the absorption layer is 1-3 mu m; the thickness of the gradual change layer is 0.01-0.1 μm, and the thickness of the charge layer is 0.1-0.5 μm; the thickness of the multiplication layer and the contact layer is 0.05-0.1 μm.
4. The mesa photodetector of claim 1, wherein the buffer layer has a doping concentration of less than 8 x 1017cm-3(ii) a The doping concentration of the graded layer is less than or equal to 1 multiplied by 1017cm-3(ii) a The doping concentration of the charge layer is 5X 1016～5×1017cm-3(ii) a The doping concentration of the multiplication layer and the doping concentration of the contact layer are both more than 1 multiplied by 1019cm-3。
5. A method for manufacturing a mesa-type photodetector with low surface leakage current is characterized by comprising the following steps:
s1, depositing a mask on the top layer of the epitaxial wafer, and forming a mesa etching window through a photoetching process;
s2, etching the epitaxial wafer into an epitaxial table top by adopting wet etching, carrying out surface chemical cleaning, and removing residual products, surface oxides and impurity contaminants of the wet etching reaction;
s3, passivating the side wall surface of the epitaxial table top by adopting a vulcanization process to reduce the surface state of the epitaxial table top;
s4, treating the surface of the side wall by using hexamethyldisilazane, and coating benzocyclobutene to form a protective layer; under the protection of nitrogen atmosphere, adopting distributed heating and curing;
s5, etching part of the protective layer to expose the top of the epitaxial table top, depositing a metal film on the upper surface of the contact layer according to an evaporation or sputtering mode, and forming a P-type electrode after stripping;
s6, thinning the back of the epitaxial table top, and depositing an antireflection film on the back;
and S7, manufacturing the N-type electrode by adopting tape stripping.
6. The method according to claim 5, wherein the step S1 specifically includes: and growing a layer of composite dielectric film on the epitaxial wafer by adopting plasma enhanced chemical vapor deposition, spin-coating photoresist by a photoetching process, after exposure and development, corroding the composite dielectric film by using hydrogen fluoride, cleaning the composite dielectric film, and leaving a mesa etching mask so as to determine a mesa etching window.
7. The method for manufacturing a mesa photodetector with low surface leakage current according to claim 5, wherein in step S2, the epitaxial wafer is etched according to the mesa etching window, and a portion of the buffer layer, the absorption layer, the graded layer, the charge layer, the multiplication layer and the contact layer in the epitaxial wafer is etched away; thereby forming an epitaxial mesa.
8. The method as claimed in claim 5, wherein the sulfidation process in step S3 uses raw material including (NH)4)2S、(NH4)2Sx、H2Any one or more of S, NaS and ZnS, and the passivation mode comprises wet chemical reaction and magnetron sputtering.
9. The method as claimed in claim 5, wherein the step of treating the sidewall surface with hexamethyldisilazane in step S4 comprises vapor coating, solution immersion, or spin coating.
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| CN111399350B (en) * | 2020-02-20 | 2023-12-26 | 武汉光安伦光电技术有限公司 | Preparation method of patterned photosensitive BCB semiconductor structure |
| CN112186071B (en) * | 2020-09-02 | 2022-06-28 | 中国电子科技集团公司第十一研究所 | Surface leakage current treatment method for antimony-based photoelectric detector |
| CN113113511B (en) * | 2021-04-12 | 2022-07-26 | 中国科学院半导体研究所 | Preparation method of detector for inhibiting side wall leakage current by using passivation layer negative electrification |
| CN113451436B (en) * | 2021-06-23 | 2023-03-24 | 中国电子科技集团公司第四十四研究所 | Nitride ultraviolet avalanche photodetector and manufacturing method thereof |
| CN113707539A (en) * | 2021-07-13 | 2021-11-26 | 武汉敏芯半导体股份有限公司 | High-speed detector passivation layer structure and manufacturing method thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101944549A (en) * | 2009-06-02 | 2011-01-12 | 瑞萨电子株式会社 | Mesa photodiode and manufacture method thereof |
| CN102376824A (en) * | 2011-10-18 | 2012-03-14 | 中国科学院上海技术物理研究所 | Manufacture method of table surface type indium gallium arsenic detector |
| CN102593169A (en) * | 2011-01-07 | 2012-07-18 | 中国科学院微电子研究所 | Carbon-based field effect transistor and preparation method thereof |
| CN103078009A (en) * | 2013-01-14 | 2013-05-01 | 中国科学院上海微系统与信息技术研究所 | Manufacture method of photoelectric detector chip for reducing dark current on basis of plasma-free process |
| CN104576811A (en) * | 2015-01-27 | 2015-04-29 | 苏州苏纳光电有限公司 | Near-middle infrared two-tone detector and preparation method thereof |
| CN107768462A (en) * | 2017-11-02 | 2018-03-06 | 天津大学 | Two-stage table top indium gallium arsenic/indium phosphorus avalanche photodide and preparation method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105118886A (en) * | 2015-08-31 | 2015-12-02 | 中国科学院半导体研究所 | High-response avalanche photodiode fabrication method |
-
2018
- 2018-11-14 CN CN201811349887.XA patent/CN109285913B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101944549A (en) * | 2009-06-02 | 2011-01-12 | 瑞萨电子株式会社 | Mesa photodiode and manufacture method thereof |
| CN102593169A (en) * | 2011-01-07 | 2012-07-18 | 中国科学院微电子研究所 | Carbon-based field effect transistor and preparation method thereof |
| CN102376824A (en) * | 2011-10-18 | 2012-03-14 | 中国科学院上海技术物理研究所 | Manufacture method of table surface type indium gallium arsenic detector |
| CN103078009A (en) * | 2013-01-14 | 2013-05-01 | 中国科学院上海微系统与信息技术研究所 | Manufacture method of photoelectric detector chip for reducing dark current on basis of plasma-free process |
| CN104576811A (en) * | 2015-01-27 | 2015-04-29 | 苏州苏纳光电有限公司 | Near-middle infrared two-tone detector and preparation method thereof |
| CN107768462A (en) * | 2017-11-02 | 2018-03-06 | 天津大学 | Two-stage table top indium gallium arsenic/indium phosphorus avalanche photodide and preparation method thereof |
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