阅读说明：本技术 一种可见光与近红外光的双波段光电探测器及其制备方法 (visible light and near infrared light dual-band photoelectric detector and preparation method thereof ) 是由 陈宜方 邓嘉男 陆冰睿 于 2019-08-02 设计创作，主要内容包括：本发明属于光电探测器技术领域,具有为一种可见光与近红外光的双波段光电探测器及其制备方法。本发明的可见光与近红外光的双波段光电探测器件,是基于二维过渡金属硫化物TMDCs/铟镓砷/铟铝砷(InGaAs/InAlAs)异质结的,其中,二维TMDCs是可见光敏感层,InGaAs是沟道层,同时也是近红外光敏感层；TMDs与InGaAs为n型掺杂,InAlAs为本征掺杂,TMDCs与InGaAs/InAlAs接触时产生一个没有内建电场的n-i-n型异质结。本发明将可见光与近红外光的双波段探测集成于单个器件,与高度成熟的传统三五族半导体器件工艺相兼容,有助于实现高灵敏度,宽探测频谱的光电探测器。(the invention belongs to the technical field of photoelectric detectors, and discloses a visible light and near infrared light dual-band photoelectric detector and a preparation method thereof. The visible light and near infrared light dual-band photoelectric detection device is based on a two-dimensional transition metal sulfide TMDCs/indium gallium arsenide/indium aluminum arsenide (InGaAs/InAlAs) heterojunction, wherein the two-dimensional TMDCs is a visible light sensitive layer, the InGaAs is a channel layer and is also a near infrared light sensitive layer; TMDS and InGaAs are doped in n type, InAlAs is doped in intrinsic type, and an n-i-n type heterojunction without built-in electric field is generated when TMDCs and InGaAs/InAlAs are contacted. The invention integrates the dual-band detection of visible light and near infrared light into a single device, is compatible with the highly mature process of the traditional III-V semiconductor device, and is beneficial to realizing a photoelectric detector with high sensitivity and wide detection spectrum.)

1. A visible light and double-waveband photoelectric detection device of near infrared light, wherein, the visible light and double-waveband photoelectric detection device of near infrared light based on two-dimensional TMDCs/InGaAs/InAlAs heterojunction; the two-dimensional TMDCs are visible light sensitive layers, the InGaAs is a channel layer and a near infrared light sensitive layer; TMDS and InGaAs are doped in an n type, InAlAs is doped in an intrinsic mode, and when TMDCs are in contact with InGaAs/InAlAs, an n-i-n type heterojunction without a built-in electric field is generated; when visible light is incident to the surface of the device, electrons or holes generated in the TMDCs are collected by the top gate electrode, so that the concentration of two-dimensional electron gas in the InGaAs/InAlAs is changed, and the change of driving current is caused; when near-infrared light enters the surface of the device, photogenerated electrons or holes are only generated in the InGaAs channel layer, TMDs are insensitive to the near-infrared light and are equivalent to a metal electrode, and due to the fact that the energy band of the InGaAs is bent, a self-amplification effect exists inside the device, and therefore photogenerated current is increased.

2. The device of claim 1, wherein an n-i-n junction exists between any of the two ends of the InGaAs channel and the TMDCs, and the device as a whole is a field effect transistor controlled by the gate resistance.

3. the method for manufacturing a visible light and near infrared light dual-band photoelectric detector as claimed in claim 1, comprising the steps of:

(1) Taking an InGaAs/InAlAs epitaxial material as a substrate;

(2) forming a graph structure of the InGaAs/InAlAs, removing the semiconductor thin film layer outside the channel region, and forming an electrical isolation table;

(3) forming a source drain electrode layer on the surface of the InGaAs/InAlAs graphic structure;

(4) directly growing a two-dimensional TMDCs film or transferring the two-dimensional TMDCs film to the surface of the InAlAs graphic structure so as to cover the semiconductor film conducting channel;

(5) and forming a gate electrode layer at the end of the TMDS.

4. The method according to claim 2, wherein the InGaAs/InAlAs material is prepared by molecular beam epitaxy or metal chemical vapor phase epitaxy, and any one of InP, GaAs, InAlAs and InGaAs or a composite structure formed by the InP, GaAs, InAlAs and InGaAs is used as the substrate and also used as the buffer layer and the cap layer of the initial material.

5. The method for preparing the semiconductor device, according to claim 2, wherein the composition of InAs, GaAs and AlAs in the InGaAs channel layer and the InAlAs barrier layer is adjustable at will.

6. The method as claimed in claim 2, wherein the InGaAs channel layer is intrinsic or lightly doped with a doping concentration of 10¹⁴-10¹⁸ cm^-3And the thickness of the InGaAs channel layer is 5-30 nm.

7. the method according to claim 2, wherein the InAlAs barrier layer is intrinsic doped, and a layer of n-type doping with a concentration of 10 is inserted at any position in the middle¹⁹-10²⁰ cm^-3the doping thickness is 1-2 nm, and the thickness of the InAlAs barrier layer is 8-20 nm.

8. According to claimThe method according to claim 2, wherein the two-dimensional TMDCs thin film is MoS₂、MoSe₂、WS₂、WSe₂Any one of them, and their alloys, the thickness of the two-dimensional TMDCs film is 0.6-100 nm.

Technical Field

the invention belongs to the technical field of photoelectric detectors, and relates to a visible light and near infrared light dual-band photoelectric detector and a preparation method thereof.

background

The photoelectric detector is an energy conversion device for converting optical signals into electrical signals, and has very wide application in digital camera shooting, satellite remote sensing imaging, industrial automatic control and automobile electronics. However, due to the forbidden bandwidth and absorption spectrum of the material itself, one photosensor can only generate a photoelectric response in a single wavelength band, and if multiple wavelength bands are to be detected to realize 24-hour monitoring, photosensors based on different materials, such as a gallium nitride-based solar blind detector for ultraviolet light, a silicon-based CMOS and CCD detector for visible light, an InGaAs avalanche diode for near infrared light, and the like, need to be equipped in one imaging system. The imaging cost greatly increased obviously by adopting a plurality of detecting devices for imaging also puts higher requirements on a subsequent discharge processing circuit, and is not favorable for the miniaturization and the low cost of an imaging system.

A large number of experiments prove that the high electron mobility transistor device based on the InGaAs/InAlAs heterojunction has ultrahigh detection responsivity and very wide bandwidth to near infrared light, so that the high electron mobility transistor device can be used for sensitive detection of high-speed weak near infrared signals.

in recent years, a detection device based on the visible light band of TMDs has been widely reported because of its high photoelectric responsivity. TMDs is a material that is bonded by intermolecular forces (van der waals forces) between layers, and can form a perfect interface with any bulk material regardless of lattice mismatch, which not only reduces the cost required for material epitaxy, but also improves the reliability of the device.

disclosure of Invention

the invention aims to provide a visible light and near infrared light dual-band photoelectric detector with good reliability and low cost and a preparation method thereof.

The visible light and near infrared light dual-band photoelectric detector combines the visible light high sensitivity of two-dimensional Transition Metal Sulfides (TMDCs) with the high sensitivity of a high electron mobility transistor device of a traditional InGaAs/InAlAs heterojunction to near infrared light to obtain a visible light and near infrared light dual-band photoelectric detector based on the two-dimensional Transition Metal Sulfides (TMDCs)/InGaAs/InAlAs heterojunction; wherein, the two-dimensional TMDCs is used as a gas sensitive layer, and the SFOI is a conductive channel. Specifically, the two-dimensional TMDCs is a visible light sensitive layer, and the InGaAs is a channel layer and a near infrared light sensitive layer. When TMDCs is contacted with InGaAs/InAlAs, the TMDCs and the InGaAs are doped in n type, and the InAlAs is doped in intrinsic mode, so that an n-i-n type heterojunction without built-in electric field is generated. When visible light is incident on the device surface, electrons or holes generated in the TMDCs are collected by the top gate electrode, thereby changing the two-dimensional electron gas concentration in InGaAs/InAlAs, causing a change in drive current. When near infrared light enters the surface of the device, photo-generated electrons or holes are only generated in the InGaAs channel layer, and TMDs are insensitive to the near infrared light and are equivalent to a metal electrode; due to the bending of the energy band of the InGaAs, a self-amplification effect exists in the device, and therefore the photo-generated current is increased.

in the invention, an n-i-n junction exists between any one of two ends of the InGaAs channel and the TMDCs, and the device is similar to a field effect transistor regulated by a gate resistor on the whole.

In summary, the two-band photoelectric detector of visible light and near infrared light of the two-dimensional transition metal sulfide/indium gallium arsenide/indium aluminum arsenide heterojunction only needs to adopt the traditional InGaAs/InAlAs epitaxial material as the substrate. The two-dimensional electron gas concentration in the lower InGaAs/InAlAs layer is regulated and controlled by the top gate electric field in TMDs, so that the two-band detection of visible light and near infrared light is realized.

The invention provides a preparation method of a visible light and near infrared light double-waveband photoelectric detection device based on a two-dimensional transition metal sulfide/indium gallium arsenic/indium aluminum arsenic heterojunction, which comprises the following specific steps:

(1) taking an InGaAs/InAlAs epitaxial material as a substrate;

(2) Forming a graph structure of the InGaAs/InAlAs, removing the semiconductor thin film layer outside the channel region, and forming an electrical isolation table;

(3) Forming a source drain electrode layer on the surface of the InGaAs/InAlAs graphic structure;

(4) Directly growing a two-dimensional TMDCs film or transferring the two-dimensional TMDCs film to the surface of the InAlAs graphic structure so as to cover the semiconductor film conducting channel;

(5) And forming a gate electrode layer at the end of the TMDS.

Preferably, the InGaAs/InAlAs material is prepared by using molecular number epitaxy or metal chemical vapor deposition technology, and any one of InP and GaAs or a composite structure formed by the InP and the GaAs is used as a substrate.

Preferably, the InGaAs/InAlAs material is prepared by using molecular number epitaxy or metal chemical vapor deposition technology, and any one of InAs and AlAs or a composite structure formed by the InAs and the AlAs is used as a growth buffer layer.

Preferably, the InGaAs/InAlAs material is prepared by using molecular number epitaxy or metal chemical vapor deposition technology, any one of InAs and GaAs or a composite structure formed by the InAs and the GaAs is used as a cap layer, and the concentration of the cap layer is 10¹⁹-10²⁰cm^-3。

Preferably, the channel layer and the barrier layer in the InGaAs/InAlAs material are InGaAs and InAlAs respectively, wherein the compositions of InAs, AlAs and GaAs can be adjusted at will.

Preferably, the InAlAs barrier layer is originally intrinsic doped, and a layer of n-type doping with the concentration of 10 is inserted in the middle part¹⁹-10²⁰ cm^-3the doping thickness is 1-2 nm, and the thickness of the InAlAs barrier layer is 8-20 nm.

preferably, the layered material is formed into an electrical isolation structure by the following specific method:

Forming photoresist on the surface of the InGaAs/InAlAs substrate material, exposing the photoresist layer by a photomask with a preset layout, developing and imaging the photoresist;

And removing the semiconductor thin film layer on the buffer layer, which is not protected by the photoresist, by using the patterned photoresist as a mask and adopting dry etching or wet etching to form an opening for exposing the insulator layer so as to obtain a mesa pattern structure, and then removing the photoresist.

preferably, a source/drain electrode is formed on the surface of the semiconductor thin film pattern structure, and the specific method comprises the following steps:

Forming photoresist on the surface of the semiconductor thin film graph structure, exposing the photoresist layer by a photomask with a preset layout, developing and imaging the photoresist;

Depositing metal by using the graphical photoresist as a mask and adopting a physical vapor deposition method, and then removing the photoresist to form a metal electrode;

The metal electrode material is selected from one or two or more of elementary metals such as Au, Pt, Ni, Ti, Cr and the like and conductive silicide, nitride, carbide and the like, or any one of alloys or laminated layers, and the thickness of the electrode material is 20-1000 nm.

Preferably, a gate groove is formed on the surface of the semiconductor thin film pattern structure, and the specific method comprises the following steps:

Forming photoresist on the surface of the semiconductor thin film graph structure, exposing the photoresist layer by a photomask with a preset layout, developing and imaging the photoresist;

And taking the patterned photoresist as a mask, etching the cap layer by adopting a dry etching method or a wet etching method, removing the semiconductor thin film layer which is not protected by the photoresist, forming an opening exposing the insulator layer to obtain a gate groove, and then removing the photoresist.

preferably, the two-dimensional TMDCs film is directly grown or transferred to the surface of the semiconductor thin film pattern structure to cover the semiconductor thin film conductive channel, and the specific method is as follows:

Directly forming a two-dimensional TMDCs film on the surface of the InAlAs barrier layer by adopting methods such as chemical vapor deposition, atomic layer deposition and the like;

On the other hand, the grown two-dimensional TMDCs thin film is transferred to the surface of the InAlAs barrier layer by taking polymer materials such as PMMA (polymethyl methacrylate), PDMS (polydimethylsiloxane) and the like as media;

the two-dimensional TMDCs film is MoS₂、MoSe₂、WS₂、WSe₂any one of them and their alloy, the thickness of the two-dimensional TMDCs film is 0.6-100 nm.

Preferably, a source and drain electrode is formed at the end of the two-dimensional TMDCs thin film, and the specific method is as follows:

Forming photoresist on the surface of the semiconductor thin film graph structure, exposing the photoresist layer by a photomask with a preset layout, developing and imaging the photoresist;

Depositing metal by using the graphical photoresist as a mask and adopting a physical vapor deposition method, and then removing the photoresist to form a metal electrode;

the metal electrode material is selected from one or two or more of elementary metals such as Au, Pt, Ni, Ti, Cr and the like and conductive silicide, nitride, carbide and the like, or any one of alloys or laminated layers, and the thickness of the electrode material is 20-1000 nm.

in the invention, the two-dimensional Transition Metal Sulfides (TMDCs) can form a perfect interface with any bulk material without considering lattice mismatch, so that the cost required by material epitaxy can be reduced, and the reliability of the device is improved. The invention integrates the dual-band detection of visible light and near infrared light into a single device, is compatible with the highly mature process of the traditional III-V semiconductor device, and is beneficial to realizing a photoelectric detector with high sensitivity and wide detection spectrum.

Drawings

Fig. 1 is a schematic structural diagram of a visible light and near infrared light dual-band photoelectric detection device based on a two-dimensional transition metal sulfide/indium gallium arsenic/indium aluminum arsenic heterojunction provided by the invention.

Fig. 2 is a schematic flow chart of a method for manufacturing a visible light and near infrared light dual-band photoelectric detection device based on a two-dimensional transition metal sulfide/indium gallium arsenic/indium aluminum arsenic heterojunction provided by the invention.

reference numbers in the figures: 101 is an initial material, 101-1 is an InP substrate, 101-2 is an InAlAs buffer layer, 101-3 is an InGaAs channel layer, 101-4 is an InAlAs barrier layer, 101-5 is a heavily doped region in the InAlAs barrier layer, and 101-6 is an InGaAs cap layer; 201 is a metal source drain electrode, 301 is a two-dimensional TMDCs, and 401 is a metal gate electrode.

Detailed Description

embodiments of the present invention will be described below by way of specific examples with reference to the accompanying drawings. The drawings are only some embodiments of the invention and other drawings may be derived from those drawings by a person skilled in the art without inventive effort. In addition, various modifications and changes may be made to the embodiments without departing from the spirit of the invention, and may be practiced or applied.

fig. 1 is a schematic structural diagram of a visible light and near infrared light dual-band photoelectric detection device based on a two-dimensional transition metal sulfide/indium gallium arsenic/indium aluminum arsenic heterojunction, and a specific preparation process is shown in fig. 2. It should be noted that the drawings provided in the embodiments are only for illustrating the basic idea of the present invention in a schematic manner, and the drawings only show the components related to the present invention rather than the number, shape and size of the components according to the actual implementation, and the types, the number and the proportions of the components can be changed and the layout of the components can be more complicated in the actual implementation.

as shown in fig. 1, the visible light and near infrared light dual-band photoelectric detector based on two-dimensional transition metal sulfide/indium gallium arsenic/indium aluminum arsenic heterojunction at least includes: a channel layer 101-3 serving as a near-infrared light absorbing layer; a barrier layer 101-4; a metal electrode layer 201; the two-dimensional TMDCs layer 301 serves as both a gate and a visible light sensitive layer.

as shown in fig. 2, the method for preparing a TMDCs-SFOI heterojunction-based gas sensor comprises:

In step S1, the starting material 101 is provided. The material 101 is formed by a substrate 101-1 to an InGaAs cap layer 101-6 together by utilizing molecular number epitaxy or chemical vapor deposition;

The substrate layer 101-1 is any one of InP, GaAs and the like or a composite structure formed by the InP, the GaAs and the like;

The buffer layer 101-2 is a ternary compound semiconductor composed of InAs and AlAs binary compounds, the components of the buffer layer can be adjusted at will, and the thickness is 100 nm-2000 nm;

the channel layer 101-3 is a ternary compound semiconductor composed of binary compounds of InAs and GaAs, and the components of the ternary compound semiconductor can be adjusted at will, and the thickness of the ternary compound semiconductor is 10 nm-30 nm;

The barrier layer 101-4 is a ternary compound semiconductor formed by binary compounds of InAs and AlAs, the components of the ternary compound semiconductor can be adjusted at will, and the thickness is 8 nm-20 nm;

the doped region 101-5 in the barrier layer has a doping concentration of 10¹⁹ cm^-3To 10²⁰cm^-3The doping thickness is 1 nm to 3 nm, and the doping area can be adjusted randomly in 101-4;

The cap layer 101-6 is a ternary compound semiconductor composed of binary compounds of InAs and GaAs, and has adjustable components, thickness of 20-30 nm, and doping concentration of 10¹⁹ cm^-3to 10²⁰cm^-3。

step S2, forming a mesa structure on 101, removing 101-3 to 101-6, and forming electrical isolation, specifically:

Step S201, cleaning and drying the initial material;

Step S202, spin-coating HMDS (hexamethyldisilazane) as an adhesion layer, firstly spin-coating at 500 rpm for 5S, and then spin-coating at 4000 rpm for 60S;

Step S203, spin-coating AZ5214 photoresist, spin-coating 500 rpm for 5S, spin-coating 4000 rpm for 60S to form a photoresist film layer with the thickness of about 1500 nm, and drying at 100 ℃ for 2 min;

step S204, photoetching, exposing the photoresist by a photomask with a preset layout, wherein the exposure dose is 60mJ/cm²Fixing in a large amount of deionized water immediately after developing for 50 s, thereby forming a pattern structure on the photoresist;

Step S205, post-baking to harden the film, and drying for 1 min at 180 ℃;

Step S206, corroding the phosphoric acid/hydrogen peroxide/water corrosive liquid for 60S, and then cleaning the corrosive liquid with deionized water; the proportion of the corrosive liquid is 3:1: 50;

Step S207, removing photoresist in acetone to form an electrical isolation structure.

Step S3, forming an electrode layer 201 on the surface of the cap layer 101-6 pattern structure, specifically:

The metal electrode material is one or two or more of elementary metals such as Au, Pt, Ni, Ti, Cr and the like and conductive silicide, nitride, carbide and the like, or any one of alloys or laminated layers;

in this embodiment, a Ti/Au metal stack is selected as the electrode layer 201;

s301, spin-coating AZ5214 photoresist on the surface of the 101-6 graph structure, spin-coating the photoresist at 500 revolutions per minute for 5S, then spin-coating the photoresist at 4000 revolutions per minute for 60S to form a photoresist film layer with the thickness of about 1500 nm, and then drying the photoresist film layer for 2 min at 95 ℃;

step S302, photoetching, exposing the photoresist by a photomask with a preset layout, wherein the exposure dose is 40mJ/cm²Fixing in a large amount of deionized water immediately after developing for 20 s, thereby forming a pattern structure on the photoresist;

step S303, putting the sample into a thermal evaporation coating machine for vacuumizing, and then depositing a 10 nm Ti and 200 nm Au lamination;

in step S304, the photoresist is removed from the acetone to form the electrode layer 201.

Step S4, etching the gate trench

s401, spin-coating AZ5214 photoresist on the surface of a 101-6 graph structure, spin-coating at 500 revolutions per minute for 5S, spin-coating at 4000 revolutions per minute for 60S to form a photoresist film layer with the thickness of about 1500 nm, and drying at 95 ℃ for 2 min;

step S302, photoetching, exposing the photoresist by a photomask with a preset layout, wherein the exposure dose is 40mJ/cm²Fixing in a large amount of deionized water immediately after developing for 20 s, thereby forming a pattern structure on the photoresist;

step S403, post-baking to harden the film, and drying for 1 min at 180 ℃;

Step S404, corroding the citric acid/hydrogen peroxide corrosive liquid for 60S, and then cleaning the corrosive liquid with deionized water; the proportion of the corrosive liquid is 1: 1;

step S405, removing the photoresist in acetone to form a groove structure under the grid.

Step S5, transferring the two-dimensional TMDCs film 301 to the surface of the 101-4 pattern structure as a visible light sensitive layer, specifically:

The two-dimensional TMDCs film is MoS₂、MoSe₂、WS₂、WSe₂Any one of them and their alloys;

In this embodiment, a few (2-10) MoS2 films are selected as the visible light sensitive layer 301;

Step S501, adhering a PDMS film on a transparent glass slide, and then adopting a micro-mechanical stripping method to remove MoS₂The film 301 is transferred to the PDMS surface to form MoS₂a/PDMS/glass slide stack;

Step S502, MoS is processed under a microscope₂MoS in/PDMS/glass slide laminated structure₂one side of the film 301 is aligned with the middle of 101-4 and is compacted to be tightly attached;

step S503, heating the transfer table to 70 ℃, the PDMS film automatically falls off, and MoS₂the film 301 is transferred to the middle of the 101-4 conduction channel to form a visible light sensitive layer.

in step S6, a gate electrode layer 401 is formed, specifically:

The metal electrode material is one or two or more of elementary metals such as Au, Pt, Ni, Ti, Cr and the like and conductive silicide, nitride, carbide and the like, or any one of alloys or laminated layers;

in this embodiment, a Ti/Au metal stack is used as the gate electrode layer 401;

step S601, spin-coating AZ5214 photoresist on the surface of the 101-6 graph structure, spin-coating the photoresist for 5S at 500 revolutions per minute, spin-coating the photoresist for 60S at 4000 revolutions per minute to form a photoresist film layer with the thickness of about 1500 nm, and then drying the photoresist film layer for 2 min at 95 ℃;

step S602, performing photolithography, exposing the photoresist with a photomask having a preset layout, wherein the exposure dose is 40mJ/cm²Immediately after 20 s displayfixing in a large amount of deionized water to form a pattern structure on the photoresist;

step S603, putting the sample into a thermal evaporation coating machine for vacuumizing, and then depositing a 10 nm Ti and 200 nm Au lamination;

in step S604, the photoresist is removed from the acetone to form the electrode layer 401.

the above embodiments are merely illustrative of the principles and effects of the present invention, and are not to be construed as limiting the invention. Any person skilled in the art can modify the above-described embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of the invention should be determined from the following claims.