CN112310234A - Infrared detector and manufacturing method thereof - Google Patents
Infrared detector and manufacturing method thereof Download PDFInfo
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- 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
- H01L31/035236—Superlattices; Multiple quantum well structures
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- 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
- H01L31/0256—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 the material
- H01L31/0264—Inorganic materials
- H01L31/0304—Inorganic materials including, apart from doping materials or other impurities, only AIIIBV compounds
- H01L31/03046—Inorganic materials including, apart from doping materials or other impurities, only AIIIBV compounds including ternary or quaternary compounds, e.g. GaAlAs, InGaAs, InGaAsP
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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 at least one potential-jump barrier or surface barrier, 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 or surface barrier
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- 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
- 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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- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
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Abstract
The invention discloses an infrared detector, wherein a P-type superlattice barrier layer (14) is a P-type InPSb/GaSb superlattice. The invention adopts InPSb/GaSb superlattice to manufacture and form the electronic barrier layer, and the barrier height of the electronic barrier layer is higher than that of the traditional InAs/GaSb superlattice electronic barrier, thereby improving the electronic barrier effect. The invention also discloses an infrared detector, wherein the N-type superlattice barrier layer (12) is an N-type InPSb/GaSb superlattice. The invention adopts InPSb/GaSb superlattice to manufacture and form the hole barrier layer, and because the hole barrier layer does not contain Al, the oxidation of Al-containing materials is avoided, the difficulty of material growth and processing is reduced, and the stability and the reliability of the device are improved. The invention also discloses a manufacturing method of the infrared detector.
Description
Technical Field
The invention belongs to the technical field of semiconductors, and particularly relates to an infrared detector and a manufacturing method thereof.
Background
Infrared radiation detection is an important component of infrared technology and is widely applied to the fields of thermal imaging, satellite remote sensing, gas monitoring, optical communication, spectral analysis and the like. The antimonide superlattice (such as InAs/GaSb and InAs/InAsSb) infrared detectors are considered to be one of the most ideal choices for preparing third-generation infrared detectors due to the characteristics of good uniformity, low Auger recombination rate, large wavelength adjusting range and the like. Compared with a mercury cadmium telluride infrared detector (HgCdTe), the mercury cadmium telluride infrared detector has better uniformity repeatability, lower cost and better performance in a very long wave band; compared with a quantum well infrared detector (QWIP), the quantum well infrared detector has the advantages of higher quantum efficiency, smaller dark current and simpler process.
An important noise source for infrared detectors is dark current. Currently, in order to suppress dark current, in the structural design of an antimonide superlattice detector, barrier layers are generally introduced into a device by using energy band engineering, such as M structure of northwest university of the united states (b. -m.nguyen et al, appl.phys.lett.91, 163511, 2007), W structure of navy laboratory (i.vurgafman et al, appl.phys.lett.89,121114,2006), electron hole complementary barrier of jet propulsion laboratory (davidz. -y.ting et al, appl.phys.lett.95, 023508, 2009), and the like. In these prior art schemes, the electron barrier is an InAs/GaSb superlattice, while the hole barrier schemes are more, but aluminum (Al) -containing materials such as InAs/AlSb superlattice, InAs/GaSb/AlSb/GaSb superlattice or InAs/InGaSb/InAs/AlGaInSb superlattice are used without exception.
However, in the prior art solutions, one of the problems is the limited height of the electron barrier using InAs/GaSb superlattices, which will affect the electron blocking effect. In addition, in the scheme of the prior art, the hole barriers all contain Al, and the Al-containing material is very easy to oxidize, which increases the growth and processing difficulty of the infrared detector and affects the stability and reliability of the device.
Disclosure of Invention
In order to solve one of the above problems, the present invention provides an infrared detector with a P-type superlattice barrier layer as a P-type inp sb/GaSb superlattice and a method for manufacturing the same.
In order to solve the second problem, the present invention provides an infrared detector with an N-type superlattice barrier layer being an N-type inp sb/GaSb superlattice and a method for manufacturing the same.
According to an aspect of the embodiments of the present invention, there is provided an infrared detector, wherein the P-type superlattice barrier layer of the infrared detector is a P-type inp sb/GaSb superlattice.
In one example of the infrared detector provided in the above aspect, the N-type superlattice barrier layer of the infrared detector is an N-type inp sb/GaSb superlattice.
According to another aspect of the embodiments of the present invention, there is provided an infrared detector, wherein the N-type superlattice barrier layer of the infrared detector is an N-type inp sb/GaSb superlattice.
In one example of the infrared detector provided in the another aspect above, the P-type superlattice barrier layer of the infrared detector is a P-type inp sb/GaSb superlattice.
In an example of the infrared detector provided in the above one aspect or another aspect, the infrared detector further includes: the device comprises a substrate, an N-type contact layer, a superlattice absorption layer, a P-type contact layer, a first electrode and a second electrode; the N-type contact layer, the N-type superlattice barrier layer, the superlattice absorption layer, the P-type superlattice barrier layer and the P-type contact layer are sequentially stacked on the substrate, the first electrode is arranged on the N-type contact layer, and the second electrode is arranged on the P-type contact layer.
In one example of the infrared detector provided in the above one or other aspects, an effective bandwidth of the N-type superlattice barrier layer is greater than an effective bandwidth of the superlattice absorber layer, and a conduction band of the N-type superlattice barrier layer is flush with a conduction band of the superlattice absorber layer; and/or the effective bandwidth of the P-type superlattice barrier layer is larger than that of the superlattice absorption layer, and the valence band of the P-type superlattice barrier layer is flush with that of the superlattice absorption layer.
In an example of the infrared detector provided in the above one aspect or another aspect, the N-type contact layer is an N-type InAs or InAsSb material; and/or the superlattice absorption layer is an InAs/GaSb superlattice or an InAs/InAsSb superlattice; and/or the P-type contact layer is a P-type GaSb or GaAsSb material; and/or the substrate is an N-type InAs substrate or an N-type GaSb substrate.
According to another aspect of the embodiments of the present invention, there is provided a method for manufacturing an infrared detector, wherein a P-type superlattice barrier layer for forming the infrared detector is manufactured by using a P-type inp sb/GaSb superlattice.
In one example of the method for manufacturing the infrared detector provided by the above further aspect, the N-type superlattice barrier layer forming the infrared detector is manufactured by using an N-type inp sb/GaSb superlattice.
According to another aspect of the embodiments of the present invention, there is provided a method for manufacturing an infrared detector, wherein an N-type superlattice barrier layer of the infrared detector is formed by using an N-type inp sb/GaSb superlattice.
In one example of the method for manufacturing the infrared detector provided by the above further aspect, the P-type superlattice barrier layer forming the infrared detector is manufactured by using a P-type inp sb/GaSb superlattice.
In an example of the method for fabricating an infrared detector provided in the above still another aspect or the still another aspect, before fabricating an N-type superlattice barrier layer for forming the infrared detector, the method further includes: manufacturing and forming an N-type contact layer on a substrate; the manufacturing of the N-type superlattice barrier layer for forming the infrared detector comprises the following steps: manufacturing and forming the N-type superlattice barrier layer on the N-type contact layer by using an N-type InPSb/GaSb superlattice; before the P-type superlattice barrier layer for forming the infrared detector is manufactured, the manufacturing method further comprises the following steps: forming a superlattice absorption layer on the N-type superlattice barrier layer; the manufacturing of the P-type superlattice barrier layer for forming the infrared detector comprises the following steps: manufacturing a P-type superlattice barrier layer on the superlattice absorption layer by using a P-type InPSb/GaSb superlattice; after the P-type superlattice barrier layer for forming the infrared detector is manufactured, the manufacturing method further comprises the following steps: forming a P-type contact layer on the P-type superlattice barrier layer; a first electrode is formed in contact with the N-type contact layer and a second electrode is deposited on the P-type contact layer.
In an example of the method for manufacturing an infrared detector provided in the above still another aspect or the still another aspect, an effective bandwidth of the N-type superlattice barrier layer is greater than an effective bandwidth of the superlattice absorption layer, and a conduction band of the N-type superlattice barrier layer is flush with a conduction band of the superlattice absorption layer; and/or the effective bandwidth of the P-type superlattice barrier layer is larger than that of the superlattice absorption layer, and the valence band of the P-type superlattice barrier layer is flush with that of the superlattice absorption layer.
In an example of the foregoing method for manufacturing an infrared detector, in yet another aspect or a further aspect, the N-type contact layer is an N-type InAs or InAsSb material; and/or the superlattice absorption layer is an InAs/GaSb superlattice or an InAs/InAsSb superlattice; and/or the P-type contact layer is a P-type GaSb or GaAsSb material; and/or the substrate is an N-type InAs substrate or an N-type GaSb substrate.
In an example of the method for manufacturing an infrared detector provided in the above still another aspect or the still another aspect, the N-type contact layer and/or the N-type superlattice barrier layer and/or the superlattice absorption layer and/or the P-type superlattice barrier layer and/or the P-type contact layer are formed by metal organic chemical vapor deposition or molecular beam epitaxy.
The invention has the beneficial effects that:the invention adopts InPSb/GaSb superlattice to manufacture and form the electronic barrier layer, and the barrier height of the electronic barrier layer is higher than that of the traditional InAs/GaSb superlattice electronic barrier, thereby improving the electronic barrier effect.
In addition, the cavity barrier layer is formed by adopting InPSb/GaSb superlattice, and because the cavity barrier layer does not contain Al, the oxidation of Al-containing materials is avoided, the difficulty of material growth and processing is reduced, and the stability and the reliability of the device are improved.
Furthermore, the invention adopts the same material, namely InPSb/GaSb superlattice to manufacture and form the electron barrier layer and the hole barrier layer, thereby greatly reducing the manufacturing difficulty of the device.
Drawings
The above and other aspects, features and advantages of embodiments of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic diagram of an infrared detector according to an embodiment of the invention;
FIG. 2 is a schematic illustration of energy bands in an infrared detector according to an embodiment of the invention;
FIG. 3 shows conduction band E of InAs/GaSb superlattice absorber layer, N-type InPSb/GaSb superlattice barrier layer, and P-type InPSb/GaSb superlattice barrier layer in an infrared detector according to an embodiment of the inventionCAnd valence band EVA schematic diagram of the comparison of relative positions;
fig. 4a to 4d are process diagrams of a method for manufacturing an infrared detector according to an embodiment of the invention.
Detailed Description
Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, these embodiments are provided to explain the principles of the invention and its practical application to thereby enable others skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use contemplated.
As used herein, the term "include" and its variants mean open-ended terms in the sense of "including, but not limited to. The terms "based on," based on, "and the like mean" based at least in part on, "" based at least in part on. The terms "an embodiment," one example, "" one embodiment, "and" an embodiment "mean" at least one embodiment. The terms "another embodiment," another example, "" yet another example "mean" at least one other embodiment. The terms "first," "second," and the like may refer to different or the same object. Other definitions, whether explicit or implicit, may be included below. The definition of a term is consistent throughout the specification unless the context clearly dictates otherwise.
It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and/or processing steps that are closely related to the solution according to the present invention are shown in the drawings, and other details that are not relevant are omitted.
As described in the background, in the prior art solutions for infrared detectors, one of the problems is the limited height of the electron barrier using the InAs/GaSb superlattice, which will affect the electron blocking effect. In addition, in the scheme of the prior art, the other problem is that the hole barrier contains aluminum (Al), and the Al-containing material is easily oxidized, which increases the growth and processing difficulty of the infrared detector and affects the stability and reliability of the infrared detector.
Therefore, in order to increase the height of the electron barrier, the embodiment of the invention provides an infrared detector which forms a P-type superlattice barrier layer by utilizing P-type InPSb/GaSb superlattice manufacture. In the infrared detector, the P-type superlattice barrier layer is a P-type InPSb/GaSb superlattice. In addition, the embodiment of the invention also provides a manufacturing method utilizing the infrared detector. In the manufacturing method of the infrared detector, a P-type superlattice barrier layer is manufactured and formed by utilizing a P-type InPSb/GaSb superlattice.
Because the barrier height of the P-type InPSb/GaSb superlattice is higher than that of the traditional InAs/GaSb superlattice electron barrier, the electron barrier layer formed by adopting the InPSb/GaSb superlattice has higher barrier height, so that the electron blocking effect can be improved.
In addition, in order to avoid containing aluminum in the hole barrier, the embodiment of the invention also provides an infrared detector which forms an N-type superlattice barrier layer by utilizing the N-type InPSb/GaSb superlattice manufacture. In the infrared detector, the N-type superlattice barrier layer is an N-type InPSb/GaSb superlattice. In addition, the embodiment of the invention also provides a manufacturing method utilizing the infrared detector. In the manufacturing method of the infrared detector, the N-type superlattice barrier layer is manufactured and formed by using the N-type InPSb/GaSb superlattice.
Because the N-type InPSb/GaSb superlattice does not contain Al, the N-type superlattice barrier layer formed by manufacturing the N-type InPSb/GaSb superlattice is not easy to oxidize, the growth and processing difficulty of the infrared detector can be reduced, and the stability and reliability of the infrared detector are improved.
An infrared detector according to embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
Fig. 1 is a schematic structural view of an infrared detector according to an embodiment of the present invention.
Referring to fig. 1, an infrared detector according to an embodiment of the present invention includes: a substrate 10; an N-type contact layer 11, an N-type superlattice barrier layer 12, a superlattice absorption layer 13, a P-type superlattice barrier layer 14, and a P-type contact layer 15 which are stacked from below to above; and a first electrode 16 and a second electrode 17; wherein the first electrode 16 is in contact with the N-type contact layer 11, and the second electrode 17 is disposed on the P-type contact layer 15.
In one example, the P-type contact layer 15, the P-type superlattice barrier layer 14, the superlattice absorption layer 13 and the N-type superlattice barrier layer 12 may be partially etched, for example, by using an inductively coupled plasma etching (ICP) process, so that the N-type contact layer 11 is exposed, and thus a mesa structure a is formed. In this case, the first electrode 16 may be disposed on the exposed N-type contact layer 11, i.e., on the mesa structure a.
In one example, the substrate 10 is an N-type InAs substrate or an N-type GaSb substrate.
In one example, the N-type contact layer 11 is an N-type InAs or InAsSb material.
In one example, the superlattice absorber layer 13 is an InAs/GaSb superlattice or an InAs/InAsSb superlattice.
In one example, the P-type contact layer 15 is a P-type GaSb or GaAsSb material.
In one example, the P-type superlattice barrier layer 14 is a P-type InPSb/GaSb superlattice and the N-type superlattice barrier layer 12 is an InAs/AlSb superlattice, InAs/GaSb/AlSb/GaSb superlattice, or InAs/InGaSb/InAs/AlGaInSb superlattice. In this case, since the barrier height of the P-type inp sb/GaSb superlattice is higher than that of the conventional InAs/GaSb superlattice electron barrier, the electron barrier layer (i.e., the P-type superlattice barrier layer 14) formed by using the inp sb/GaSb superlattice has a higher barrier height, so that the electron blocking effect can be improved.
In another example, the P-type superlattice barrier layer 14 is an InAs/GaSb superlattice and the N-type superlattice barrier layer 12 is an N-type InPSb/GaSb superlattice. In this case, since the N-type inp sb/GaSb superlattice does not contain Al, the N-type superlattice barrier layer 12 formed by manufacturing the same is not easily oxidized, so that the difficulty in growth and processing of the infrared detector can be reduced, and the stability and reliability of the infrared detector can be improved.
In yet another example, the P-type superlattice barrier layer 14 is a P-type inp sb/GaSb superlattice and the N-type superlattice barrier layer 12 is an N-type inp sb/GaSb superlattice. In this case, in addition to the above two advantages (high barrier height and not easy to be oxidized), the P-type superlattice barrier layer 14 and the N-type superlattice barrier layer 12 are made of the same material (i.e., inp sb/GaSb superlattice), which can further reduce the difficulty of growth and preparation.
Further, in one example, the thickness of the N-type contact layer 11 is 0.1 μm to 0.5 μm, the doping source is Si, and the doping concentration is 1 × 1018cm-3～1×1019cm-3The corresponding bandwidth is 0.3eV to 0.4 eV.
In one example, the N-type superlattice barrier layer 12 has a thickness of 0.2-0.5 μm, and the doping source is Si with a doping concentration of 1 × 1018cm-3～1×1019cm-3The corresponding bandwidth is 0.3eV to 0.5 eV.
In one example, the superlattice absorber layer 13 has a thickness of 2 μm to 5 μm, is unintentionally doped, and has a corresponding bandwidth of 0.1eV to 0.3 eV.
In one example, the P-type superlattice barrier layer 14 has a thickness of 0.2 μm to 0.5 μm, and the doping source is Zn or Be with a doping concentration of 1 × 1018cm-3～1×1019cm-3The corresponding bandwidth is 0.3eV to 0.5 eV.
In one example, the thickness of the P-type contact layer 15 is 0.1 μm to 0.5 μm, and the doping source is selectedWith Zn or Be, doping concentration of 1X 1018cm-3～1×1019cm-3The corresponding bandwidth is 0.6eV to 0.8 eV.
The energy bands in the infrared detector according to an embodiment of the present invention are described in detail below. Fig. 2 is a schematic diagram of energy bands in an infrared detector according to an embodiment of the invention.
Referring to fig. 1 and 2 together, the effective bandwidth of the N-type superlattice barrier layer 12 is made larger than the effective bandwidth of the superlattice absorption layer 13, and the conduction band E of the N-type superlattice barrier layer 12 is made largerCConduction band E with said superlattice absorption layer 13CFlush and therefore can constitute a hole barrier.
Further, the effective bandwidth of the P-type superlattice barrier layer 14 is made larger than that of the superlattice absorption layer 13, and the valence band E of the P-type superlattice barrier layer 14 is made largerVAnd the valence band E of the superlattice absorption layer 13VFlush and therefore may constitute an electron barrier.
Therefore, when the infrared detector operates, a double-heterojunction structure is formed between the N-type superlattice barrier layer 12, the P-type superlattice barrier layer 14 and the superlattice absorption layer 13, the N-type superlattice barrier layer 12 is a hole barrier layer, and the P-type superlattice barrier layer 14 is an electron barrier layer.
Further, for electron-hole pairs formed by generating photocurrent at the superlattice absorption layer 13, electrons are collected by the N-type contact layer 11 after passing through the N-type superlattice barrier layer 12, and holes are collected by the P-type contact layer 15 after passing through the P-type superlattice barrier layer 14. And the electrons thermally excited in the superlattice absorption layer 13 are blocked by the electron barrier of the P-type superlattice barrier layer 14, and the thermally excited holes are blocked by the hole barrier of the N-type superlattice barrier layer 12, so that the dark current of the detector is suppressed. That is to say, the double-heterojunction structure can inhibit the dark current and noise of the infrared detector, and simultaneously ensures the normal absorption of the photocurrent, thereby improving the detection performance of the infrared detector.
In the infrared detector according to the embodiment of the invention, the InPSb/GaSb superlattice can be used as an electron barrier layer and a hole barrier layer of InAs/GaSb or InAs/InAsSb superlattice at the same time to form the double heterojunction structure, and only the thickness ratio of the InPSb/GaSb superlattice needs to be adjusted. The physical mechanism of the superlattice absorption layer 13 is illustrated by taking InAs/GaSb superlattice as an example.
FIG. 3 shows conduction band E of InAs/GaSb superlattice absorber layer, N-type InPSb/GaSb superlattice barrier layer, and P-type InPSb/GaSb superlattice barrier layer in an infrared detector according to an embodiment of the inventionCAnd valence band EVComparative schematic of relative position.
InAs and GaSb form a second type of energy band arrangement, and the conduction band E of the effective bandwidth after the formation of the microstripCAnd valence band EVAs shown in fig. 3. The P-type superlattice barrier layer 14 is composed of an InPSb/GaSb superlattice, wherein the valence band E of the InPSb materialVPosition similar to InAs, and conduction band ECAbout 0.2eV above the InAs. Therefore, after the superlattice is formed by InPSb and GaSb, if the thickness of InPSb is consistent with that of InAs in the InAs/GaSb superlattice and the thickness of GaSb is consistent with that of GaSb in the InAs/GaSb superlattice, the valence band E of the InPSb/GaSb superlattice microstrip is ensuredVValence band E with InAs/GaSb superlatticeVConduction band E of flat superlattice microstripCConduction band E higher than InAs/GaSb superlatticeCThereby forming a very perfect electron barrier layer.
For the N-type superlattice barrier layer 12, the ratio of inp sb in the inp sb/GaSb superlattice needs to be increased to decrease the ratio of GaSb, and at this time, the conduction band E of the superlattice microstrip isCThe position is sharply reduced to reach the InAs/GaSb superlattice conduction band ECFlat state and valence band E of superlattice microstripVThen must be lower than the valence band E of the InAs/GaSb superlatticeV。
Therefore, through material engineering and energy band engineering, the InPSb/GaSb superlattice realizes an electronic barrier layer and a hole barrier layer which are perfect for the InAs/GaSb superlattice, and the design and production difficulty is greatly simplified. As an electron barrier, the barrier height is higher than that of the traditional InAs/GaSb superlattice electron barrier. In addition, the InPSb/GaSb superlattice does not contain Al, compared with the scheme in the prior art, the difficulty of material growth and processing can be reduced, and the stability and the reliability of the infrared detector production are improved. The material based on the InPSb/GaSb superlattice can be used as an electron barrier layer and a hole barrier layer of short-wave, medium-wave and long-wave infrared detectors, is suitable for infrared detectors with various wavelengths, and has strong universality.
The following describes a process of manufacturing an infrared detector according to an embodiment of the present invention in detail. Fig. 4a to 4d are process diagrams of a method for manufacturing an infrared detector according to an embodiment of the invention.
Referring to fig. 4a, a substrate 10 is provided. In one example, the substrate 10 may be an N-type InAs substrate or an N-type GaSb substrate.
Referring to fig. 4b, an N-type contact layer 11, an N-type superlattice barrier layer 12, a superlattice absorption layer 13, a P-type superlattice barrier layer 14, and a P-type contact layer 15 are sequentially grown on the substrate 10 from bottom to top (i.e., stacked in sequence).
In one example, an N-type contact layer 11, an N-type superlattice barrier layer 12, a superlattice absorber layer 13, a P-type superlattice barrier layer 14, and a P-type contact layer 15 may be sequentially grown on the substrate 10 from bottom to top using a metal-organic chemical vapor deposition (MOCVD) process. Specifically, a metal organic chemical vapor deposition process is used as a growth process, and the growth sources are TMGa, TMIn, TMSb and AsH3And pH3The n-type doping source is SiH4The p-type dopant source was DEZn, the growth temperature was set at about 600 ℃, and the reaction chamber pressure was set at 200 Torr. After the high temperature treatment removes the impurities on the surface of the substrate 10 in step S1, the growth is performed on the substrate 10 in order from below:
(1) an N-type contact layer 11. In one example, the N-type contact layer 11 is an N-type InAs material with a thickness of 0.5 μm, doped with Si and a doping concentration of 1 × 1019cm-3The corresponding bandwidth is 0.3 eV.
(2) An N-type superlattice barrier layer 12. In one example, the N-type superlattice barrier layer 12 is an N-type InPSb/GaSb superlattice with a thickness of 0.5 μm, doped with Si at a doping concentration of 5 × 1018cm-3The conduction band is flush with the conduction band of the superlattice absorber layer 13, corresponding to a bandwidth of 0.4 eV.
(3) A superlattice absorber layer 13. In one example, the superlattice absorber layer 13 is an InAs/GaSb superlattice with a thickness of 5 μm and is unintentionally doped with a corresponding bandwidth of 0.1 eV.
(4) A P-type superlattice barrier layer 14. In one example, the P-type superlattice barrier layer 14 is a P-type InPSb/GaSb superlattice with a thickness of 0.5 μm, doped with Zn at a doping concentration of 5 × 1018cm-3The corresponding bandwidth is 0.3eV, and the valence band is flush with the valence band of the superlattice absorption layer 13.
(5) A P-type contact layer 15. In one example, the P-type contact layer 15 is P-type GaAsSb material with a thickness of 0.2 μm, doped with Zn with a doping concentration of 1 × 1019cm-3The corresponding bandwidth is 0.6 eV.
In another example, a molecular beam epitaxy process (MBE process) may Be used As the growth process, the growth sources being solid elemental sources of Ga, In, As, P, and Sb, the n-type dopant source being Si, the P-type dopant source being Be, and the growth temperature being about 400 ℃. After the substrate 10 is degassed and decontaminated, the substrate 10 is grown sequentially from below to above:
(1) an N-type contact layer 11. In one example, the N-type contact layer 11 is an N-type InAsSb material with a thickness of 0.2 μm, doped with Si and a doping concentration of 2 × 1018cm-3The corresponding bandwidth is 0.3 eV.
(2) An N-type superlattice barrier layer 12. In one example, the N-type superlattice barrier layer 12 is an N-type InPSb/GaSb superlattice with a thickness of 0.2 μm, doped with Si with a doping concentration of 1 × 1018cm-3The corresponding bandwidth is 0.5eV, and the conduction band of the superlattice absorption layer is flush with the conduction band of the superlattice absorption layer 13;
(3) a superlattice absorber layer 13. In one example, the superlattice absorber layer 13 is an InAs/InAsSb superlattice with a thickness of 2 μm and is unintentionally doped with a corresponding bandwidth of 0.25 eV.
(4) A P-type superlattice barrier layer 14. In one example, the P-type superlattice barrier layer 14 is a P-type InPSb/GaSb superlattice with a thickness of 0.2 μm, doped with Be and a doping concentration of 1 × 1018cm-3The corresponding bandwidth is 0.4eV, and the valence band is flush with the valence band of the superlattice absorption layer 13.
(5) A P-type contact layer 15. In one exampleThe P-type contact layer 15 is P-type GaSb material with thickness of 0.1 μm, doped with Be and doping concentration of 2 × 1018cm-3The corresponding bandwidth is 0.7 eV.
Referring to fig. 4c, the P-type contact layer 15, the P-type superlattice barrier layer 14, the superlattice absorption layer 13, and the N-type superlattice barrier layer 12 are partially etched to form a mesa structure a exposing the N-type contact layer 11.
In one example, the P-type contact layer 15, the P-type superlattice barrier layer 14, the superlattice absorption layer 13, and the N-type superlattice barrier layer 12 may be partially etched using an inductively coupled plasma etching (ICP) process to expose the N-type contact layer 11, thereby forming a mesa structure a.
Referring to fig. 4d, a first electrode 16 is deposited on the N-type contact layer 11, and a second electrode 17 is deposited on the P-type contact layer 15.
In one example, an e-beam evaporation process may be used to deposit a first electrode 16 on the exposed N-type contact layer 11 and a second electrode 17 on the P-type contact layer 15. In one example, the first electrode 16 and the second electrode 17 are both Ti (thickness of
) Pt (thickness of
) /Au (thickness of
) Combinations of (a) and (b).
In another example, an e-beam evaporation process may be used to deposit a first electrode 16 on the exposed N-type contact layer 11 and a second electrode 17 on the P-type contact layer 15. In another example, the first electrode 16 and the second electrode 17 are both Ti (thickness of
) Pt (thickness of
) /Au (thickness of
) Combinations of (a) and (b).
In one example, an MOCVD process is adopted as a growth process of the N-type contact layer 11, the N-type superlattice barrier layer 12, the superlattice absorption layer 13, the P-type superlattice barrier layer 14 and the P-type contact layer 15, so that the cost can be reduced, and the cost performance of the manufactured infrared detector can be improved.
In another example, an MBE process is used as a growth process of the N-type contact layer 11, the N-type superlattice barrier layer 12, the superlattice absorber layer 13, the P-type superlattice barrier layer 14, and the P-type contact layer 15, and the MBE process and parameters described above obtain the superlattice absorber layer 13 having a cutoff wavelength of about 5 μm, which is in the medium-wave infrared. Because the MBE process can form a steep interface, the performance of the obtained medium-wave infrared detector is higher.
In summary, according to the infrared detector and the manufacturing method thereof provided by the embodiment of the invention, a brand new inp sb/GaSb superlattice is adopted, and when the ratio of inp sb is low, the inp sb/GaSb superlattice can be flush with the valence band of InAs/GaSb superlattice or InAs/InAsSb superlattice, so that an electron barrier is realized; and when the proportion of GaSb is low, the InPSb/GaSb superlattice can be flush with the conduction band of the InAs/GaSb superlattice or the InAs/InAsSb superlattice, and a hole barrier is realized. Therefore, the InPSb/GaSb superlattice is adopted to realize the perfect electron barrier layer and hole barrier layer for the InAs/GaSb superlattice or the InAs/InAsSb superlattice, and the design and production difficulty is greatly simplified. In addition, when the InPSb/GaSb superlattice is used as an electron barrier, the barrier height provided by the InPSb/GaSb superlattice is higher than that of the traditional InAs/GaSb superlattice electron barrier. Furthermore, the InPSb/GaSb superlattice does not contain Al, compared with the scheme in the prior art, the formed barrier layer is not easy to oxidize, the difficulty of material growth and processing can be reduced, and the stability and the reliability of the infrared detector production are improved. Furthermore, the material based on the InPSb/GaSb superlattice can be used as an electron barrier layer and a hole barrier layer of short-wave, medium-wave and long-wave infrared detectors, is suitable for infrared detectors with various wavelengths, and has strong universality.
The terms "exemplary," "example," and the like, as used throughout this specification, mean "serving as an example, instance, or illustration," and do not mean "preferred" or "advantageous" over other embodiments. The detailed description includes specific details for the purpose of providing an understanding of the described technology. However, the techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described embodiments.
Alternative embodiments of the present invention are described in detail with reference to the drawings, however, the embodiments of the present invention are not limited to the specific details in the above embodiments, and within the technical idea of the embodiments of the present invention, many simple modifications may be made to the technical solution of the embodiments of the present invention, and these simple modifications all belong to the protection scope of the embodiments of the present invention.
The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the description is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. An infrared detector is characterized in that a P-type superlattice barrier layer (14) of the infrared detector is a P-type InPSb/GaSb superlattice.
2. An infrared detector according to claim 1, characterized in that the N-type superlattice barrier layer (12) of the infrared detector is an N-type inp sb/GaSb superlattice.
3. An infrared detector is characterized in that an N-type superlattice barrier layer (12) of the infrared detector is an N-type InPSb/GaSb superlattice.
4. The infrared detector according to any one of claims 1 to 3, characterized in that the infrared detector further comprises: the semiconductor device comprises a substrate (10), an N-type contact layer (11), a superlattice absorption layer (13), a P-type contact layer (15), a first electrode (16) and a second electrode (17);
wherein the N-type contact layer (11), the N-type superlattice barrier layer (12), the superlattice absorption layer (13), the P-type superlattice barrier layer (14), and the P-type contact layer (15) are sequentially stacked on the substrate (10), the first electrode (16) is disposed on the N-type contact layer (11), and the second electrode (17) is disposed on the P-type contact layer (15).
5. The infrared detector as set forth in claim 4,
the effective bandwidth of the N-type superlattice barrier layer (12) is larger than that of the superlattice absorption layer (13), and the conduction band of the N-type superlattice barrier layer (12) is flush with that of the superlattice absorption layer (13);
and/or the effective bandwidth of the P-type superlattice barrier layer (14) is larger than that of the superlattice absorption layer (13), and the valence band of the P-type superlattice barrier layer (14) is level with that of the superlattice absorption layer (13).
6. A method for manufacturing an infrared detector is characterized by comprising the following steps: and a P-type superlattice barrier layer (14) of the infrared detector is formed by utilizing the P-type InPSb/GaSb superlattice.
7. The method of claim 6, further comprising: and manufacturing an N-type superlattice barrier layer (12) for forming the infrared detector by using an N-type InPSb/GaSb superlattice.
8. The manufacturing method of the infrared detector is characterized in that an N-type superlattice barrier layer (12) of the infrared detector is manufactured and formed by utilizing an N-type InPSb/GaSb superlattice.
9. The method of fabricating an infrared detector according to any of claims 6 to 8, wherein before fabricating the N-type superlattice barrier layer (12) forming the infrared detector, the method of fabricating further comprises: manufacturing and forming an N-type contact layer (11) on a substrate (10);
the manufacturing of the N-type superlattice barrier layer (12) for forming the infrared detector comprises the following steps: forming the N-type superlattice barrier layer (12) on the N-type contact layer (11) by using an N-type InPSb/GaSb superlattice;
before fabricating a P-type superlattice barrier layer (14) forming the infrared detector, the fabrication method further comprises: forming a superlattice absorption layer (13) on the N-type superlattice barrier layer (12);
the manufacturing of the P-type superlattice barrier layer (14) for forming the infrared detector comprises the following steps: a P-type superlattice barrier layer (14) is manufactured and formed on the superlattice absorption layer (13) by utilizing a P-type InPSb/GaSb superlattice;
after fabricating a P-type superlattice barrier layer (14) that forms the infrared detector, the fabrication method further includes: forming a P-type contact layer (15) on the P-type superlattice barrier layer (14); forming a first electrode (16) in contact with the N-type contact layer (11), and depositing a second electrode (17) on the P-type contact layer (15).
10. The method of claim 9, wherein the step of forming the infrared detector,
the effective bandwidth of the N-type superlattice barrier layer (12) is larger than that of the superlattice absorption layer (13), and the conduction band of the N-type superlattice barrier layer (12) is flush with that of the superlattice absorption layer (13);
and/or the effective bandwidth of the P-type superlattice barrier layer (14) is larger than that of the superlattice absorption layer (13), and the valence band of the P-type superlattice barrier layer (14) is level with that of the superlattice absorption layer (13).
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| CN113035992A (en) * | 2021-02-26 | 2021-06-25 | 中国科学院半导体研究所 | Complementary potential barrier superlattice long-wave infrared detector |
| CN116705882A (en) * | 2023-08-08 | 2023-09-05 | 中科爱毕赛思(常州)光电科技有限公司 | Epitaxial material structure of low-defect superlattice infrared detector and preparation method |
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| CN113035992A (en) * | 2021-02-26 | 2021-06-25 | 中国科学院半导体研究所 | Complementary potential barrier superlattice long-wave infrared detector |
| CN116705882A (en) * | 2023-08-08 | 2023-09-05 | 中科爱毕赛思(常州)光电科技有限公司 | Epitaxial material structure of low-defect superlattice infrared detector and preparation method |
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