CN115188854A - Photoelectric detector and preparation method thereof - Google Patents
Photoelectric detector and preparation method thereof Download PDFInfo
- Publication number
- CN115188854A CN115188854A CN202210777449.3A CN202210777449A CN115188854A CN 115188854 A CN115188854 A CN 115188854A CN 202210777449 A CN202210777449 A CN 202210777449A CN 115188854 A CN115188854 A CN 115188854A
- Authority
- CN
- China
- Prior art keywords
- layer
- type contact
- type
- contact layer
- substrate
- 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.)
- Pending
Links
- 238000002360 preparation method Methods 0.000 title abstract description 3
- 238000010521 absorption reaction Methods 0.000 claims abstract description 60
- 239000000758 substrate Substances 0.000 claims abstract description 48
- 230000000903 blocking effect Effects 0.000 claims abstract description 38
- 238000002161 passivation Methods 0.000 claims abstract description 36
- 238000000034 method Methods 0.000 claims description 20
- 238000005530 etching Methods 0.000 claims description 15
- 238000001312 dry etching Methods 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 238000001039 wet etching Methods 0.000 claims description 9
- 239000006096 absorbing agent Substances 0.000 claims description 7
- 238000001514 detection method Methods 0.000 claims description 7
- 238000009616 inductively coupled plasma Methods 0.000 claims description 7
- 238000009792 diffusion process Methods 0.000 claims description 4
- 238000005468 ion implantation Methods 0.000 claims description 4
- 239000004065 semiconductor Substances 0.000 abstract 1
- 229920002120 photoresistant polymer Polymers 0.000 description 13
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 8
- 238000010586 diagram Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 4
- 238000000206 photolithography Methods 0.000 description 4
- 238000001020 plasma etching Methods 0.000 description 4
- 235000012239 silicon dioxide Nutrition 0.000 description 4
- 239000000377 silicon dioxide Substances 0.000 description 4
- 238000005229 chemical vapour deposition Methods 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000005566 electron beam evaporation Methods 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 238000001755 magnetron sputter deposition Methods 0.000 description 2
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 229910001020 Au alloy Inorganic materials 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000011982 device technology Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005247 gettering Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000001451 molecular beam epitaxy Methods 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
Images
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
-
- 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
- H01L31/0248—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 characterised by their semiconductor bodies
- H01L31/0352—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 characterised by their semiconductor bodies characterised by their shape or by the shapes, relative sizes or disposition of the semiconductor regions
-
- 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
- H01L31/0248—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 characterised by their semiconductor bodies
- H01L31/0352—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 characterised by their semiconductor bodies characterised by their shape or by the shapes, relative sizes or disposition of the semiconductor regions
- H01L31/035272—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 characterised by their semiconductor bodies characterised by their shape or by the shapes, relative sizes or disposition of the semiconductor regions characterised by at least one potential jump barrier or surface barrier
- H01L31/035281—Shape of the body
-
- 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
- H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Light Receiving Elements (AREA)
Abstract
The present disclosure provides a photodetector including: the semiconductor device comprises a substrate, an N-type contact layer, a collecting layer, a cliff layer, an absorption layer, an electron blocking layer, a P-type contact layer, a passivation layer, a first through hole, a second through hole, a P-type electrode, an N-type electrode and a micro lens, wherein the passivation layer is grown on the upper surface of the substrate, the upper surface and the side surface of the N-type contact layer, the side surfaces of the collecting layer and the cliff layer, the upper surface and the side surface of the absorption layer, the side surface of the electron blocking layer and the upper surface and the side surface of the P-type contact layer; the first through hole is formed in a passivation layer grown on the upper surface of the N-type contact layer; the second through hole is formed in the passivation layer grown on the upper surface of the P-type contact layer; the P-type electrode is grown in the first through hole and is in contact with the upper surface of the P-type contact layer; the N-type electrode is grown in the second through hole and is in contact with the upper surface of the N-type contact layer; the micro lens is arranged on the lower surface of the substrate. The disclosure also provides a preparation method of the photoelectric detector.
Description
Technical Field
The present disclosure relates to the field of optoelectronic device technologies, and in particular, to a photodetector and a method for manufacturing the same.
Background
A single-carrier photodetector (UTC) refers to a device in which a photogenerated hole relaxes rapidly in picoseconds, and only one carrier of electrons is transported. The drift velocity of electrons is about one order of magnitude greater than that of holes, so that the space charge effect is effectively relieved, the detector structure is most suitable for a high-power analog optical communication system receiver, and the detector structure becomes a research hotspot in the field of recent photoelectrons. The single carrier photoelectric detector used in the communication field at present mainly comprises a waveguide type single carrier photoelectric detector and a surface incidence type single carrier photoelectric detector. The thickness of an absorption layer of the waveguide type single carrier photoelectric detector is less than 1 μm, while the diameter of an incident light spot is usually more than 2 μm, and high coupling efficiency with an incident optical fiber is difficult to obtain due to a thin coupling section. The surface incidence type single carrier photoelectric detector structure has the mutual restriction of responsivity and bandwidth due to the coupling of optical signal absorption and carrier transport paths. Therefore, the single carrier photoelectric detector cannot simultaneously realize high-response and high-bandwidth optical detection, and the application is limited to a certain extent.
Disclosure of Invention
In view of the above, the present disclosure provides a photodetector and a method of manufacturing the same.
According to a first aspect of the present disclosure, there is provided a photodetector comprising:
a substrate;
the N-type contact layer is arranged in the middle of the upper surface of the substrate;
the collecting layer is arranged in the middle of the upper surface of the N-type contact layer;
the cliff layer is arranged on the upper surface of the collection layer;
the absorption layer is arranged on the upper surface of the cliff layer;
the electron blocking layer is arranged in the middle of the upper surface of the absorption layer;
the P-type contact layer is arranged on the upper surface of the electron blocking layer;
the passivation layer is grown on the upper surface of the substrate, the upper surface and the side surface of the N-type contact layer, the side surfaces of the collecting layer and the cliff layer, the upper surface and the side surface of the absorption layer, the side surface of the electron blocking layer and the upper surface and the side surface of the P-type contact layer;
the first through hole is formed in the passivation layer grown on the upper surface of the N-type contact layer;
the second through hole is formed on the passivation layer grown on the upper surface of the P-type contact layer;
the P-type electrode is grown in the first through hole and is in contact with the upper surface of the P-type contact layer;
the N-type electrode grows in the second through hole and is in contact with the upper surface of the N-type contact layer;
and the micro lens is arranged on the lower surface of the substrate.
Optionally, the microlens comprises a monolithically integrated lens;
the focal length of the micro lens is larger than the thickness of the substrate;
the contact area of the micro lens and the substrate is larger than the area of the lower surface of the absorption layer.
Optionally, the p-type electrode and the n-type electrode are both coplanar electrode structures;
the photodetector comprises M n-type electrodes, M = I or M =2;
when M =2, M n-type electrodes are symmetrically distributed about the collection layer and are connected to each other.
Optionally, the absorption layer comprises an intrinsic absorption layer and a doped layer, the doped layer comprises p-type doping, and the doping type of the doped layer comprises any one of uniform doping and gradient doping;
the doping mode of the doping layer comprises any one of ion implantation and diffusion;
the intrinsic absorption layer comprises a PN junction which is a buried junction.
Optionally, the photodetector detection wavelength comprises an infrared band.
Optionally, the width of the P-type contact layer is equal to the width of the electron blocking layer;
the width of the electron blocking layer is smaller than that of the absorption layer;
the width of the absorption layer is equal to the width of the cliff layer;
the width of the cliff layer is equal to the width of the collection layer;
the width of the collection layer is smaller than that of the N-type contact layer.
According to a second aspect of the present disclosure, there is provided a method of manufacturing a photodetector, the method comprising:
sequentially growing an N-type contact layer, a collection layer, a cliff layer, an absorption layer, an electron blocking layer and a P-type contact layer on the upper surface of the substrate;
etching the first preset area of the electron blocking layer and the P-type contact layer to expose the absorption layer and form a first table top;
etching the second preset areas of the collecting layer, the cliff layer and the absorption layer to expose the N-type contact layer and form a second table-board;
etching a third preset area of the N-type contact layer to expose the substrate and form a third table top;
preparing a passivation layer on the upper surface of the substrate, the upper surface and the side surface of the N-type contact layer, the side surfaces of the collecting layer and the cliff layer, the upper surface and the side surface of the absorption layer, the side surface of the electron blocking layer and the upper surface and the side surface of the P-type contact layer;
etching the fourth preset area of the passivation layer to obtain a first through hole so as to expose the N-type contact layer;
preparing an n-type electrode in the first through hole;
etching a fifth preset area of the passivation layer to obtain a second through hole so as to expose the P-type contact layer;
preparing a p-type electrode in the second through hole;
thinning the substrate to a preset thickness;
and preparing a micro lens on the lower surface of the substrate to obtain the photoelectric detector.
Optionally, the preset thickness is 150 to 200 μm.
Optionally, the width of the first mesa comprises 5-12 μm and the width of the second mesa comprises 15-20 μm.
Optionally, the etching method of the first mesa, the second mesa, and the third mesa includes: any one of ICP dry etching, wet etching and ICP dry etching and then wet etching.
Drawings
In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings used in the embodiments or the description in the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 schematically illustrates a structural schematic diagram of a photodetector provided by an embodiment of the present disclosure;
fig. 2 schematically illustrates a structural diagram of an absorption layer of a photodetector provided by an embodiment of the present disclosure;
fig. 3 schematically illustrates a flow chart of a method for manufacturing a photodetector according to an embodiment of the present disclosure; and
fig. 4A to 4K schematically illustrate a schematic structural diagram of a photodetector in each step of a method for manufacturing a photodetector according to an embodiment of the present disclosure.
Description of reference numerals:
1, a substrate; a 2N type contact layer; 3 a collection layer; 4 cliff layer; 5 an absorption layer; 6 an electron blocking layer; a 7P type contact layer; 8 a passivation layer; a 9 p-type electrode; a 10 n-type electrode; 11 micro lenses; 51 an intrinsic absorber layer; 52 doped layer.
Detailed Description
Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood that the description is illustrative only and is not intended to limit the scope of the present disclosure. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the disclosure. It may be evident, however, that one or more embodiments may be practiced without these specific details. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The terms "comprises," "comprising," and the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components.
All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It is noted that the terms used herein should be interpreted as having a meaning that is consistent with the context of this specification and should not be interpreted in an idealized or overly formal sense.
Where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). Where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "a or B" should be understood to include the possibility of "a" or "B", or "a and B".
The present disclosure provides a photodetector and a method for manufacturing the same, the photodetector including: a substrate; an N-type contact layer arranged in the middle of the upper surface of the substrate; a collecting layer arranged in the middle of the upper surface of the N-type contact layer; a cliff layer disposed on an upper surface of the collection layer; an absorption layer provided on an upper surface of the cliff layer; an electron blocking layer arranged in the middle of the upper surface of the absorption layer; a P-type contact layer disposed on the upper surface of the electron blocking layer; a passivation layer grown on an upper surface of the substrate, an upper surface and a side surface of the N-type contact layer, side surfaces of the collector layer and the cliff layer, an upper surface and a side surface of the absorber layer, a side surface of the electron blocking layer, and an upper surface and a side surface of the P-type contact layer; a first through hole opened on the passivation layer grown on the upper surface of the N-type contact layer; a second through hole opened on the passivation layer grown on the upper surface of the P-type contact layer; a P-type electrode grown in the first through hole and contacting with the upper surface of the P-type contact layer; an N-type electrode grown in the second via hole and contacting with the upper surface of the N-type contact layer; and a microlens disposed on a lower surface of the substrate. The photoelectric detector comprises three stages of table tops, and the bandwidth and the responsivity of the device can be controlled by controlling the widths of the three table tops, so that the photoelectric detector can realize high-speed and high-response detection at the same time.
A photodetector of the disclosed embodiment will be described in detail below with reference to fig. 1 to 2. So that those skilled in the art can more clearly understand the technical solution of the present disclosure.
Fig. 1 schematically illustrates a structural schematic diagram of a photodetector provided by an embodiment of the present disclosure.
As shown in fig. 1, in an embodiment of the present disclosure, the photodetector includes: a substrate 1; an N-type contact layer 2 provided in the middle of the upper surface of the substrate 1; a collecting layer 3 disposed in the middle of the upper surface of the N-type contact layer 2; a cliff layer 4 provided on the upper surface of the collection layer 3; an absorption layer 5 provided on the top surface of the cliff layer 4; an electron blocking layer 6 provided in the middle of the upper surface of the absorption layer 5; a P-type contact layer 7 provided on the upper surface of the electron blocking layer 6; a passivation layer 8 grown on the top surface of the substrate 1, the top surface and the side surfaces of the N-type contact layer 2, the side surfaces of the gettering layer 3 and the cliff layer 4, the top surface and the side surfaces of the absorption layer 5, the side surfaces of the electron blocking layer 6, and the top surface and the side surfaces of the P-type contact layer 7; a first through hole opened in the passivation layer 8 grown on the upper surface of the N-type contact layer 2; a second through hole opened in the passivation layer 8 grown on the upper surface of the P-type contact layer 7; a P-type electrode 9 grown in the first via hole and contacting an upper surface of the P-type contact layer 7; an N-type electrode 10 grown in the second via hole and contacting the upper surface of the N-type contact layer 2; and a microlens 11 provided on the lower surface of the substrate 1.
In this embodiment, an N-type contact layer 2, a collection layer 3, a cliff layer 4, an absorption layer 5, an electron blocking layer 6 and a P-type contact layer 7 are sequentially disposed on the upper surface of a substrate 1, wherein the N-type contact layer 2 is disposed in the middle of the upper surface of the substrate 1, the collection layer 3 is disposed in the middle of the upper surface of the N-type contact layer 2, the electron blocking layer 6 is disposed in the middle of the upper surface of the absorption layer 5, and the P-type contact layer 7 has a width equal to that of the electron blocking layer 6, the electron blocking layer 6 has a width smaller than that of the absorption layer 5, the absorption layer 5 has a width equal to that of the cliff layer 4 and that of the collection layer 3, and the collection layer 3 has a width smaller than that of the N-type contact layer 2 (as shown in fig. 1). A passivation layer 8 is further grown on the upper surface of the above structure, that is, the passivation layer 8 is grown on the upper surface of the substrate 1, the upper surface and the side surface of the N-type contact layer 2, the side surfaces of the collector layer 3 and the cliff layer 4, the upper surface and the side surface of the absorber layer 5, the side surface of the electron blocking layer 6, and the upper surface and the side surface of the P-type contact layer 7, wherein a first through hole is formed in the passivation layer 8 on the upper surface of the N-type contact layer 2, a second through hole is formed in the passivation layer 8 on the upper surface of the P-type contact layer 7, a P-type electrode 9 and an N-type electrode 10 are grown in the first through hole and the second through hole, the P-type electrode 9 and the N-type electrode 10 are all coplanar electrode structures, the photodetector in this embodiment includes M N-type electrodes 10, M =1 or M =2, when M =2, the M N-type electrodes 10 are symmetrically distributed with respect to the collector layer 3, and the M N-type electrodes 10 are connected. The lower surface of the substrate 1 is further provided with a microlens 11, the microlens 11 can be a monolithic integrated lens, the focal length of the microlens 11 in this embodiment is greater than the thickness of the substrate 1, and the contact area between the microlens 11 and the substrate 1 is greater than the area of the lower surface of the absorption layer 5. In this embodiment, the photodetector detection wavelength provided by the present disclosure includes an infrared light band. The photoelectric detector provided by the present disclosure includes a three-level mesa, the bandwidth and responsivity of the device can be controlled by controlling the width of the three-level mesa, specifically, the junction area of the PN junction can be controlled by controlling the width of the mesa formed between the absorption layer 5 and the electron blocking layer 6, and then the bandwidth of the device can be controlled, the responsivity of the device can be controlled by controlling the width of the mesa formed between the N-type contact layer 2 and the collection layer 3 (i.e., the width of the absorption layer 5), so that the photoelectric detector can simultaneously realize high-speed and high-response detection.
It should be understood that the illustration of the number of n-type electrodes, the detection wavelength of the photodetector, and the like in the present embodiment is only exemplary to help those skilled in the art understand the technical solution of the present disclosure, and is not intended to limit the protection scope of the present disclosure.
Fig. 2 schematically illustrates a structural diagram of an absorption layer of a photodetector provided by an embodiment of the present disclosure.
As shown in fig. 2, in an embodiment of the present disclosure, the absorption layer 5 of the photodetector includes an intrinsic absorption layer 51 and a doped layer 52, the doped layer 52 includes p-type doping, and a doping type of the doped layer 52 includes any one of uniform doping and gradient doping; the doping method of the doping layer 52 includes any one of ion implantation and diffusion; the intrinsic absorption layer 51 includes a PN junction, which is a buried junction.
In the present embodiment, the absorption layer 5 includes an intrinsic absorption layer 51 and a doped layer 52, referring to fig. 2, the intrinsic absorption layer 51 is close to the cliff layer 4, the doped layer 52 is close to the electron blocking layer 6, the doping manner of the doped layer 52 in the present embodiment includes any one of ion implantation and diffusion, specifically, the doping manner may be selected according to requirements, the intrinsic absorption layer 51 in the present embodiment includes a PN junction, and the PN junction is a buried junction.
It should be understood that the photodetectors shown in fig. 1 and 2 are merely exemplary to facilitate an understanding of the aspects of the present disclosure by one skilled in the art, and are not intended to limit the scope of the present disclosure. In other embodiments, the materials, sizes, shapes, and the like of the layers in the photodetector may be selected according to practical situations, and are not limited herein.
Based on the above photodetector, the present disclosure also provides a method for manufacturing a photodetector, which will be described in detail below with reference to fig. 3 to 4K.
Fig. 3 schematically illustrates a flow chart of a method for manufacturing a photodetector according to an embodiment of the present disclosure. Fig. 4A to 4K schematically illustrate a schematic structural diagram of a photodetector in each step of a method for manufacturing a photodetector according to an embodiment of the present disclosure.
As shown in fig. 3, in an embodiment of the present disclosure, the method includes operations S301 to S311.
In operation S301, an N-type contact layer, a collection layer, a cliff layer, an absorption layer, an electron blocking layer, and a P-type contact layer are sequentially grown on an upper surface of a substrate.
Referring to fig. 4A and fig. 2, in the present embodiment, an N-type contact layer, a collector layer, a cliff layer, an absorber layer, an electron blocking layer, and a P-type contact layer are grown on the upper surface of the substrate, and the growth method in the present embodiment includes Metal Organic Chemical Vapor Deposition (MOCVD), molecular Beam Epitaxy (MBE), chemical Vapor Deposition (CVD), or the like. The doping concentration of the N-type contact layer can be 1 × 10 18 cm -3 ～3×10 19 cm -3 Preferably 1X 10 19 cm -3 The thickness may be 300nm to 800nm, and may preferably be 500nm. The collector layer may be lightly n-doped or undoped with a doping concentration of less than 2 × 10 15 /cm 3 And may preferably be 1 × 10 15 /cm 3 The collector layer may be selected from InP or silicon. The cliff layer is doped n-type with a doping concentration less than 3 × 10 17 /cm 3 And may preferably be 1.4 × 10 17 /cm 3 The thickness may be 30nm to 100nm, preferably 70nm. The doped layer in the absorption layer is doped p-type, and the doping concentration can be 1 × 10 18 cm -3 ～3×10 18 cm -3 The doping layer has a thickness of 100nm to 600nm, preferably 400nm, and the intrinsic absorption layer has a thickness of 100nm to 300nm, preferably 100nm. The electron blocking layer is doped p-type with a doping concentration of 1 × 10 18 cm -3 ～5×10 18 cm -3 Preferably 2X 10 18 cm -3 The thickness may be 100nm to 300nm, preferably 100nm. The doping concentration of the P-type contact layer is 1 x 10 greater 19 /cm 3 And may preferably be 3 × 10 19 /cm 3 The thickness may be 50nm to 100nm, preferably 80nm.
In operation S302, a first predetermined region of the electron blocking layer and the P-type contact layer is etched to expose the absorption layer, thereby forming a first mesa.
Referring to fig. 4B, in this embodiment, a photoresist is applied to a region of the upper surface of the P-type contact layer outside the first predetermined region, and the P-type contact layer and the electron blocking layer outside the photoresist mask are removed by using the photoresist as a mask, optionally using photolithography, dry etching and wet etching, to form the first mesa. In this embodiment, the width of the first mesa includes 5 to 12 μm.
In operation S303, a second predetermined area of the collector layer, the cliff layer, and the absorber layer is etched to expose the N-type contact layer, forming a second mesa.
Referring to fig. 4C, in this embodiment, a photoresist is applied outside the second predetermined region on the upper surface of the absorption layer, and the collection layer, the cliff layer and the absorption layer outside the photoresist mask are removed by photolithography, dry etching and wet etching using the photoresist as a mask until the N-type contact layer is exposed, so as to form a second mesa, wherein the width of the second mesa is 15-20 μm in this embodiment.
In operation S304, a third predetermined region of the N-type contact layer is etched to expose the substrate, forming a third mesa.
Referring to fig. 4D, in this embodiment, a photoresist is coated outside a third predetermined region on the upper surface of the N-type contact layer, the photoresist is used as a mask, the N-type contact layer outside the photoresist mask is removed by photolithography, dry etching and wet etching, the substrate is exposed, and a second mesa is formed
In operation S305, passivation layers are prepared on the upper surface of the substrate, the upper surface and the side surfaces of the N-type contact layer, the side surfaces of the collector layer and the cliff layer, the upper surface and the side surfaces of the absorber layer, the side surfaces of the electron blocking layer, and the upper surface and the side surfaces of the P-type contact layer.
Referring to fig. 4E, in this embodiment, the material of the passivation layer may be silicon dioxide, and when the silicon dioxide passivation layer is grown, the device is first cleaned by organic and inorganic cleaning, and then the silicon dioxide passivation layer is prepared by using a plasma enhanced chemical vapor deposition system (PECVD) or an inductively coupled plasma vapor deposition system (ICPCVD). The thickness of the silicon dioxide passivation layer in this embodiment may be 200 to 1000nm, preferably 500nm.
In operation S306, a fourth predetermined region of the passivation layer is etched to obtain a first via hole, so as to expose the N-type contact layer.
Referring to fig. 4F, in this embodiment, a photoresist is selected as a mask, and a first through hole is opened in a fourth preset region of the passivation layer by using a reactive ion etching apparatus (RIE) or a hydrofluoric acid solution etching manner, so as to expose the N-type contact layer.
In operation S307, an n-type electrode is prepared within the first via hole.
Referring to fig. 4G, in the present embodiment, an N-type electrode is formed in the first via hole, and the N-type electrode and the N-type contact layer are electrically connected to form a good ohmic contact. When the number of the n-type electrodes is 2, the n-type electrodes are connected with each other. The material of the n-type electrode may be AuGeNi/Au alloy, ti/Au, ti/Pt/Au, etc. The method for preparing the n-type electrode comprises any one of electron beam evaporation and magnetron sputtering.
In operation S308, a fifth predetermined area of the passivation layer is etched to obtain a second via hole to expose the P-type contact layer.
Referring to fig. 4H, in this embodiment, a photoresist is selected as a mask, and a second through hole is opened in a fifth preset region of the passivation layer by using a Reactive Ion Etching (RIE) or a hydrofluoric acid solution etching manner, so as to expose the P-type contact layer.
In operation S309, a p-type electrode is prepared in the second via hole.
Referring to fig. 4I, in the present embodiment, a P-type electrode is formed in the second via hole, and the P-type electrode and the P-type contact layer are electrically connected to form a good ohmic contact. The material of the p-type electrode may be Ti/Au, ti/Pt/Au, etc. The method for preparing the p-type electrode comprises any one of electron beam evaporation and magnetron sputtering.
In operation S310, the substrate is thinned to a preset thickness.
Referring to fig. 4J, in this embodiment, in order to integrate the microlens, the substrate needs to be thinned, the thinning manner may include manual thinning or machine thinning, and the thinning liquid used for thinning may be Al 2 O 3 ∶H 2 O = 1: 3. The predetermined thickness is 150 to 200 μm in this embodiment.
In operation S311, a microlens is prepared on the lower surface of the substrate to obtain a photodetector.
Referring to fig. 4K, in this embodiment, the shape of the microlens is defined by photolithography, the excess photoresist is removed by development to leave a cylindrical pattern, heating is performed to perform hot melting, so that the photoresist pattern presents a spherical crown-shaped microlens pattern, and finally the microlens pattern is transferred to the back of the photodetector by ICP dry etching.
In the present embodiment, the absorption layer includes a PN junction, and since the area of the formed PN junction is determined by the area of the first mesa, the area of the PN junction < the area of the second mesa, that is, the formed PN junction is a buried junction. Under the structure, the area of a depletion region of the absorption layer only partially contributes to the capacitance of the PN junction, the area of the whole absorption layer can absorb incident light, and the bandwidth formula of the photoelectric detector shows that when the capacitance is small, the photoelectric detector can realize high bandwidth. The etching method of the first mesa, the second mesa, and the third mesa in this embodiment includes any one of ICP dry etching, wet etching, and ICP dry etching first and then wet etching.
It should be noted that the above descriptions of the dimensions, materials, etc. of the various layers in the photodetector are merely exemplary to facilitate understanding of the aspects of the present disclosure by those skilled in the art, and are not intended to limit the scope of the present disclosure. In other embodiments, the size, material, and the like of each layer in the photodetector may be selected according to practical situations, and are not limited herein.
Those skilled in the art will appreciate that various combinations and/or combinations of features recited in the various embodiments and/or claims of the present disclosure can be made, even if such combinations or combinations are not expressly recited in the present disclosure. In particular, various combinations and/or combinations of the features recited in the various embodiments and/or claims of the present disclosure may be made without departing from the spirit or teaching of the present disclosure. All such combinations and/or associations are within the scope of the present disclosure.
The embodiments of the present disclosure have been described above. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. While the disclosure has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents. Accordingly, the scope of the present disclosure should not be limited to the above-described embodiments, but should be defined not only by the appended claims, but also by equivalents thereof.
Claims (10)
1. A photodetector, comprising:
a substrate (1);
the N-type contact layer (2) is arranged in the middle of the upper surface of the substrate (1);
the collecting layer (3) is arranged in the middle of the upper surface of the N-type contact layer (2);
a cliff layer (4) arranged on the upper surface of the collection layer (3);
an absorption layer (5) provided on the upper surface of the cliff layer (4);
the electron blocking layer (6) is arranged in the middle of the upper surface of the absorption layer (5);
the P-type contact layer (7) is arranged on the upper surface of the electron blocking layer (6);
a passivation layer (8) grown on the upper surface of the substrate (1), the upper surface and the side surfaces of the N-type contact layer (2), the side surfaces of the collector layer (3) and the cliff layer (4), the upper surface and the side surfaces of the absorber layer (5), the side surfaces of the electron blocking layer (6), and the upper surface and the side surfaces of the P-type contact layer (7);
the first through hole is formed in the passivation layer (8) grown on the upper surface of the N-type contact layer (2);
the second through hole is formed in the passivation layer (8) grown on the upper surface of the P-type contact layer (7);
a P-type electrode (9) growing in the first through hole and contacting with the upper surface of the P-type contact layer (7);
the N-type electrode (10) is grown in the second through hole and is in contact with the upper surface of the N-type contact layer (2);
and a microlens (11) provided on the lower surface of the substrate (1).
2. A photodetector according to claim 1, characterized in that said microlens (11) comprises a monolithically integrated lens;
the focal length of the micro lens (11) is larger than the thickness of the substrate (1);
the contact area of the micro lens (11) and the substrate (1) is larger than the area of the lower surface of the absorption layer (5).
3. The photodetector of claim 1,
the p-type electrode (9) and the n-type electrode (10) are both in a coplanar electrode structure;
the photodetector comprises M of said n-type electrodes (10), M =1 or M =2;
when M =2, M n-type electrodes (10) are symmetrically distributed about the collection layer (3), and M n-type electrodes (10) are connected with each other.
4. The photodetector according to claim 1, characterized in that said absorption layer (5) comprises an intrinsic absorption layer (51) and a doped layer (52), said doped layer (52) comprising a p-type doping, the doping type of said doped layer (52) comprising any one of a homogeneous doping and a graded doping;
the doping mode of the doping layer (52) comprises any one of ion implantation and diffusion;
the intrinsic absorption layer (51) comprises a PN junction, and the PN junction is a buried junction.
5. The photodetector of claim 1, wherein the photodetector detection wavelength comprises an infrared band of light.
6. A photodetector according to claim 1, characterized in that the width of the P-contact layer (7) is equal to the width of the electron blocking layer (6);
the width of the electron blocking layer (6) is smaller than that of the absorption layer (5);
the width of the absorption layer (5) is equal to the width of the cliff layer (4);
the width of the cliff layer (4) is equal to the width of the collection layer (3);
the width of the collecting layer (3) is smaller than that of the N-type contact layer (2).
7. A method of fabricating a photodetector as claimed in any one of claims 1 to 6, characterised in that the method comprises:
sequentially growing an N-type contact layer, a collection layer, a cliff layer, an absorption layer, an electron blocking layer and a P-type contact layer on the upper surface of the substrate;
etching the first preset areas of the electron blocking layer and the P-type contact layer to expose the absorption layer and form a first table top;
etching second preset areas of the collecting layer, the cliff layer and the absorption layer to expose the N-type contact layer to form a second table-board;
etching a third preset area of the N-type contact layer to expose the substrate and form a third table-board;
preparing a passivation layer on the upper surface of the substrate, the upper surface and the side surface of the N-type contact layer, the side surfaces of the collecting layer and the cliff layer, the upper surface and the side surface of the absorption layer, the side surface of the electron blocking layer and the upper surface and the side surface of the P-type contact layer;
etching the fourth preset area of the passivation layer to obtain a first through hole so as to expose the N-type contact layer;
preparing an n-type electrode in the first through hole;
etching a fifth preset area of the passivation layer to obtain a second through hole so as to expose the P-type contact layer;
preparing a p-type electrode in the second through hole;
thinning the substrate to a preset thickness;
and preparing a micro lens on the lower surface of the substrate to obtain the photoelectric detector.
8. The method of claim 7, wherein the predetermined thickness is 150 to 200 μm.
9. The method of claim 7, wherein the width of the first mesa comprises 5-12 μm and the width of the second mesa comprises 15-20 μm.
10. The method of claim 7, wherein the etching of the first, second, and third mesas comprises: any one of ICP dry etching, wet etching and ICP dry etching and then wet etching.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210777449.3A CN115188854A (en) | 2022-07-01 | 2022-07-01 | Photoelectric detector and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210777449.3A CN115188854A (en) | 2022-07-01 | 2022-07-01 | Photoelectric detector and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115188854A true CN115188854A (en) | 2022-10-14 |
Family
ID=83515415
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210777449.3A Pending CN115188854A (en) | 2022-07-01 | 2022-07-01 | Photoelectric detector and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115188854A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117374167A (en) * | 2023-12-07 | 2024-01-09 | 上海三菲半导体有限公司 | Manufacturing method of high-speed high-power single-row carrier detector based on shallow etching |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20180331246A1 (en) * | 2014-12-05 | 2018-11-15 | Nippon Telegraph And Telephone Corporation | Avalanche photodiode |
| CN110690323A (en) * | 2019-10-08 | 2020-01-14 | 中国电子科技集团公司第十三研究所 | Preparation method of ultraviolet photoelectric detector and ultraviolet photoelectric detector |
| CN112490302A (en) * | 2020-12-03 | 2021-03-12 | 中国科学院半导体研究所 | Multi-electrode high-speed photoelectric detector and preparation method thereof |
| CN113540263A (en) * | 2021-09-16 | 2021-10-22 | 福建慧芯激光科技有限公司 | Detector with low surface leakage current and manufacturing method thereof |
| CN113707748A (en) * | 2021-08-27 | 2021-11-26 | 中国科学院半导体研究所 | Epitaxial wafer and photoelectric detector chip |
-
2022
- 2022-07-01 CN CN202210777449.3A patent/CN115188854A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20180331246A1 (en) * | 2014-12-05 | 2018-11-15 | Nippon Telegraph And Telephone Corporation | Avalanche photodiode |
| CN110690323A (en) * | 2019-10-08 | 2020-01-14 | 中国电子科技集团公司第十三研究所 | Preparation method of ultraviolet photoelectric detector and ultraviolet photoelectric detector |
| CN112490302A (en) * | 2020-12-03 | 2021-03-12 | 中国科学院半导体研究所 | Multi-electrode high-speed photoelectric detector and preparation method thereof |
| CN113707748A (en) * | 2021-08-27 | 2021-11-26 | 中国科学院半导体研究所 | Epitaxial wafer and photoelectric detector chip |
| CN113540263A (en) * | 2021-09-16 | 2021-10-22 | 福建慧芯激光科技有限公司 | Detector with low surface leakage current and manufacturing method thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117374167A (en) * | 2023-12-07 | 2024-01-09 | 上海三菲半导体有限公司 | Manufacturing method of high-speed high-power single-row carrier detector based on shallow etching |
| CN117374167B (en) * | 2023-12-07 | 2024-03-12 | 上海三菲半导体有限公司 | Manufacturing method of high-speed high-power single-row carrier detector based on shallow etching |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7397101B1 (en) | Germanium silicon heterostructure photodetectors | |
| US8357960B1 (en) | Multispectral imaging device and manufacturing thereof | |
| CN105789366B (en) | A kind of silicon substrate hybrid integrated avalanche photodetector | |
| CN104576786B (en) | Novel zero volt response avalanche photodetector chip and preparation method thereof | |
| CN110896112B (en) | Waveguide integrated GeSn photoelectric detector and manufacturing method thereof | |
| CN112490302B (en) | Multi-electrode high-speed photoelectric detector and preparation method thereof | |
| WO2020103396A1 (en) | Waveguide-type photoelectric detector and manufacturing method therefor | |
| CN104576810A (en) | Coplanar electrode analog photoelectric detector chip and manufacturing method thereof | |
| WO2020191961A1 (en) | Waveguide type gepb infrared photodetector, and manufacturing method therefor | |
| CN210136887U (en) | Waveguide type photoelectric detector | |
| CN113707751B (en) | Single photon avalanche photoelectric detector and preparation method thereof | |
| US11742449B2 (en) | Single photon avalanche diode device | |
| CN115188854A (en) | Photoelectric detector and preparation method thereof | |
| CN204067379U (en) | Novel zero volt response avalanche photodetector chip | |
| CN112201723A (en) | Waveguide type photoelectric detector and preparation method thereof | |
| EP1204148A2 (en) | Planar resonant cavity enhanced photodetector | |
| JPH04246868A (en) | P-i-n photodiode and method of improving efficiency thereof | |
| CN112117345B (en) | Diffraction ring structure type II superlattice infrared detector and preparation method thereof | |
| CN112289883B (en) | Three-dimensional semiconductor avalanche photoelectric detection chip and preparation method thereof | |
| KR101066604B1 (en) | Method of fabricating avalanche photodiode | |
| CN114023831A (en) | High-speed high-response photoelectric detector and manufacturing method thereof | |
| CN115440834A (en) | Waveguide type silicon-based short-wave infrared band avalanche photodetector and manufacturing method thereof | |
| JPH04263475A (en) | Semiconductor photodetector and manufacture thereof | |
| CN114400267B (en) | Photoelectric detector integrated with double absorption areas and preparation method thereof | |
| CN113707750B (en) | Waveguide-coupled avalanche photodetector and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |