阅读说明：本技术 一种MoS2和GaAs异质结红外探测器及制备方法 (MoS2GaAs heterojunction infrared detector and preparation method thereof ) 是由 潘昌翊 邓惠勇 汪越 殷子薇 窦伟 刘赤县 张祎 姚晓梅 戴宁 于 2021-08-13 设计创作，主要内容包括：本发明公开了一种MoS-(2)和GaAs异质结红外探测器及制备方法,该探测器包含GaAs基底、红外光吸收区、电荷传输层、电荷阻挡区和引线电极,制备方法包括四个步骤,即通过光刻、离子注入、二维材料转移和薄膜淀积等技术在高阻GaAs基底上依次形成红外光吸收区、电荷阻挡区、电荷传输层和引线电极。本发明的优点是：使用不同的材料充当红外光吸收区和电荷传输层,利用MoS-(2)和GaAs之间形成的异质结电场将红外光吸收区内产生的光生载流子(电子或空穴)注入到电荷传输层内,通过电荷传输层电导率的变化来检测红外光信号,减小了红外光吸收区内热激发载流子对器件暗电流的影响,可以提高非本征半导体红外探测器的工作温度,并且相应的器件制备方法简单可行。(The invention discloses a MoS 2 The GaAs heterojunction infrared detector comprises a GaAs substrate, an infrared light absorption area, a charge transmission layer, a charge blocking area and a lead electrode, and the preparation method comprises four steps of sequentially forming the infrared light absorption area, the charge blocking area, the charge transmission layer and the lead electrode on the high-resistance GaAs substrate through technologies such as photoetching, ion implantation, two-dimensional material transfer, thin film deposition and the like. The invention has the advantages that: using MoS with different materials acting as infrared light absorbing region and charge transport layer 2 The heterojunction electric field formed between the infrared light absorption region and the GaAs injects photon-generated carriers (electrons or holes) generated in the infrared light absorption region into the charge transport layer, and the infrared light signal is detected through the change of the conductivity of the charge transport layer, so that the infrared light absorption region is reducedThe influence of the internal heat excited carriers on the dark current of the device can improve the working temperature of the extrinsic semiconductor infrared detector, and the preparation method of the corresponding device is simple and feasible.)

1. MoS₂And GaAs heterojunction infrared detector, including GaAs basement (1), lead wire electrode (2), electric charge block district (3), infrared light absorption district (4) and charge transport layer (5), its characterized in that:

the infrared detector adopts a planar structure, namely a lead electrode (2), a charge blocking region (3), an infrared light absorbing region (4) and a charge transmission layer (5) are all positioned on the surface of the GaAs substrate (1);

the charge transport layer (5) is positioned above the infrared absorption region (4), and the lead electrodes (2) are positioned at two ends of the charge transport layer (5);

a heterojunction is formed between the infrared light absorption region (4) and the charge transport layer (5), and a photogenerated carrier generated in the infrared light absorption region (4) can be injected into the charge transport layer (5) under the drive of a heterojunction electric field.

2. A MoS according to claim 1₂And a GaAs heterojunction infrared detector, which is characterized in that: the GaAs substrate (1) is of high resistance type, and the impurity concentration range is 1 × 10¹²～1×10¹⁴cm^-3。

3. A MoS according to claim 1₂And a GaAs heterojunction infrared detector, which is characterized in that: the infrared light absorption region (4) is doped GaAs material, the doping element is Mg, S or Te, and the impurity concentration range is 5 multiplied by 10¹⁵～1×10¹⁷cm^-3。

4. A method of making the MoS of claim 1₂And a GaAs heterojunction infrared detector, characterized by comprising the steps of:

firstly, making an infrared light absorption area pattern on the surface of a GaAs substrate (1) by utilizing an ultraviolet lithography process;

doping the absorption region by using an ion implantation process to obtain an infrared light absorption region (4);

utilizing two-dimensional material transfer technology to transfer MoS₂Transferring to the surface of the infrared absorption region (4) to form a charge transport layer (5);

fourthly, utilizing the electron beam lithography technology to perform MoS₂Electrode area patterns are manufactured at two ends, and then metal films are evaporated to form the lead electrodes (2).

Technical Field

The invention relates to a long-wave infrared detector and a preparation method thereof, and the MoS₂And the GaAs heterojunction infrared detector is particularly suitable for the infrared detection field within the wavelength range of 50-300 mu m.

Background

The infrared detection is a technology for acquiring target information by using an infrared band (760 nm-1 mm), can detect information which cannot be acquired by other bands, and is widely applied to various fields such as military affairs, science, industrial and agricultural production, medical treatment and health care and the like. Common infrared detectors include thermal detectors, intrinsic semiconductor infrared detectors, extrinsic semiconductor infrared detectors, quantum well detectors, and the like. The extrinsic semiconductor infrared detector absorbs photons by utilizing impurity atoms in an extrinsic semiconductor material, and the detection wavelength is determined by ionization activation energy of impurities. According to ionization activation energy of common impurities in silicon, germanium and gallium arsenide materials, detection wavelengths of the silicon-based, germanium-based and gallium arsenide-based extrinsic infrared detectors cover 4-50 microns, 40-200 microns and 50-300 microns respectively. Compared with other types of infrared detectors, the extrinsic semiconductor infrared detector has the advantages of high detection rate, high response speed, good radiation resistance and the like, has become a mainstream detector in the field of middle and far infrared astronomical detection, and is widely applied to various large astronomical detection platforms, such as wide-field infrared measurement detection satellites (WISE), Spitzer space telescopes, James-Weber space telescopes (JWST) and the like.

For conventional extrinsic semiconductor infrared detectors, it is often necessary to operate the detector at liquid helium temperature in order to suppress dark current generated by thermal excitation of impurities. The demand for liquid helium refrigerant limits the effective service time of the detector on the outer space detection platform on one hand, and the application of the detector in the common commercial field on the other hand due to the high cost of the liquid helium. Therefore, a novel infrared detector structure is designed, the working temperature of the detector is improved, and the infrared detector has very obvious scientific research and commercial values.

Disclosure of Invention

The invention aims to provide a MoS₂And a GaAs heterojunction type extrinsic semiconductor infrared detector, and provides a preparation method for realizing the structure, which solves the technical problem of low working temperature of the traditional extrinsic semiconductor infrared detector. The structure and the working mode of the novel detector are different from those of a traditional extrinsic semiconductor infrared detector, and the novel detector is characterized in that:

the long-wave infrared detector adopts a planar structure, namely a lead electrode, a charge blocking area, an infrared light absorption area and a charge transmission layer are all positioned on the surface of the GaAs substrate;

the charge transmission layer is positioned on the infrared light absorption area, and the lead electrodes are positioned at two ends of the charge transmission layer;

the GaAs substrate is high-resistance type, and the impurity concentration range is 1 × 10¹²～1×10¹⁴cm^-3。

The infrared light absorption region is doped with GaAs material, the doping element is Mg, S or Te, and the impurity concentration range is 5 × 10¹⁵～1×10¹⁷cm^-3。

A heterojunction is formed between the infrared light absorption region and the charge transport layer, and a photon-generated carrier generated in the infrared light absorption region can be injected into the charge transport layer under the driving of a heterojunction electric field.

A preparation method for realizing the detector comprises the following steps:

firstly, making an infrared light absorption area pattern on the surface of a GaAs substrate by utilizing an ultraviolet lithography process;

doping the absorption region by using an ion implantation process to obtain an infrared light absorption region;

utilizing two-dimensional material transfer technology to transfer MoS₂Transferring to the surface of the infrared absorption area to form a charge transport layer;

fourthly, utilizing the electron beam lithography technology to perform MoS₂Electrode area patterns are manufactured at two ends, and then metal films are evaporated to form lead electrodes.

The invention has the advantages that:

1. the invention uses the body material as the infrared light absorption area, and has high infrared light absorption efficiency;

2. the invention inherits the advantages of the traditional extrinsic semiconductor infrared detector, has long detectable wavelength, avoids the defects of the traditional extrinsic semiconductor infrared detector and can work at higher temperature;

3. the invention has simple structure and low preparation cost, is compatible with the current semiconductor process, and is easy to popularize and apply to other material systems.

Drawings

FIG. 1 is a diagram of the detector of the present invention.

Fig. 2 is a schematic view of a device process flow according to an embodiment of the invention.

Detailed Description

The invention is further described in the following description of the invention with reference to examples, which are not intended to limit the scope of the invention, but rather are intended to cover all embodiments within the scope of the invention as described in the summary of the invention and the accompanying description. The preparation method of the detector is realized by the following steps:

example 1:

selecting an intrinsically undoped GaAs substrate 1 with a doping concentration of less than 1X 10¹³cm^-3Making an absorption region pattern on the surface of a substrate by means of an ultraviolet lithography technology, wherein the thickness of the used photoresist is about 3 mu m and can be used as a masking agent in the subsequent ion implantation process;

implanting Te impurity into the infrared light absorption region 4 through multiple ion implantation processes to a depth of about 0.5 μm and a doping concentration of about 1×10¹⁶cm^-3；

MoS by two-dimensional material transfer technique₂Transferring the material to the surface of the infrared absorption region 4 to form a charge transport layer 5;

electrode area patterns are manufactured at two ends of the charge transmission layer 5 by using an electron beam lithography technology;

ni with a thickness of 20nm and Au with a thickness of 80nm are deposited by using an electron beam evaporation technology to form a lead electrode.

Example 2:

selecting an intrinsically undoped GaAs substrate 1 with a doping concentration of less than 1X 10¹³cm^-3Making an absorption region pattern on the surface of a substrate by means of an ultraviolet lithography technology, wherein the thickness of the used photoresist 6 is about 3 mu m and can be used as a masking agent in the subsequent ion implantation process;

implanting Mg impurity into the infrared light absorption region 4 by multiple ion implantation processes to a depth of about 0.5 μm and a doping concentration of about 5 × 10¹⁶cm^-3；

MoS by two-dimensional material transfer technique₂Transferring the material to the surface of the infrared absorption region 4 to form a charge transport layer 5;

electrode area patterns are manufactured at two ends of the charge transmission layer 5 by using an electron beam lithography technology;

and depositing Ti with the thickness of 20nm and Au with the thickness of 80nm by using an electron beam evaporation technology to form a lead electrode.

Example 3:

selecting an intrinsically undoped GaAs substrate 1 with a doping concentration of less than 1X 10¹³cm^-3Making an absorption region pattern on the surface of a substrate by means of an ultraviolet lithography technology, wherein the thickness of the used photoresist 6 is about 3 mu m and can be used as a masking agent in the subsequent ion implantation process;

implanting S impurity into the infrared light absorption region 4 through multiple ion implantation processes to a depth of about 0.5 μm and a doping concentration of about 3 × 10¹⁶cm^-3；

MoS by two-dimensional material transfer technique₂Transferring the material to the surface of the infrared absorption region 4 to form a charge transport layer 5;

electrode area patterns are manufactured at two ends of the charge transmission layer 5 by using an electron beam lithography technology;

and depositing nickel with the thickness of 20nm and gold with the thickness of 80nm by using an electron beam evaporation technology to form a lead electrode.