阅读说明：本技术 一种可调控的室温黑砷磷太赫兹探测器及制备方法 (Adjustable room-temperature black arsenic-phosphorus terahertz detector and preparation method thereof ) 是由 王林 郭万龙 郭程 陈效双 陆卫 于 2019-11-18 设计创作，主要内容包括：本发明公开了一种可调控的室温黑砷磷太赫兹探测器及制备方法。器件结构自下而上依次为：第一层是衬底、第二层是黑砷磷以及搭在黑砷磷上的蝶形天线和与天线相连的金属电极、第三层是介质层，第四层是栅极。器件制备步骤是用机械剥离的方法将黑砷磷转移到衬底上，用电子束曝光和电子束沉积技术制备蝶形天线和金属电极，用原子层沉积工艺生长栅介质层，用电子束曝光和电子束沉积技术制备栅极，形成太赫兹探测器。其工作原理是，通过非对称的高效太赫兹天线实现高度局域和增强的太赫兹混频电场，生成响应信号。该探测器具有高速、宽频和高灵敏等特点，可实现源漏偏压和栅电压的双重调控，为实现室温太赫兹探测器大规模应用提供了原型器件。(The invention discloses an adjustable room-temperature black arsenic phosphorus terahertz detector and a preparation method thereof. The device structure is from bottom to top: the first layer is a substrate, the second layer is black arsenic phosphorus, a butterfly antenna lapped on the black arsenic phosphorus, a metal electrode connected with the antenna, the third layer is a dielectric layer, and the fourth layer is a grid. The preparation method of the terahertz detector comprises the steps of transferring black arsenic phosphorus onto a substrate by using a mechanical stripping method, preparing a butterfly antenna and a metal electrode by using electron beam exposure and electron beam deposition technologies, growing a gate dielectric layer by using an atomic layer deposition technology, and preparing a gate by using the electron beam exposure and electron beam deposition technologies to form the terahertz detector. The working principle of the terahertz frequency mixing antenna is that a high-local-area and enhanced terahertz frequency mixing electric field is realized through the asymmetric high-efficiency terahertz antenna, and a response signal is generated. The detector has the characteristics of high speed, wide frequency, high sensitivity and the like, can realize double regulation and control of source-drain bias voltage and gate voltage, and provides a prototype device for realizing large-scale application of the room-temperature terahertz detector.)

1. The utility model provides a room temperature black arsenic phosphorus terahertz detector that can regulate and control, includes substrate (1), black arsenic phosphorus (2), butterfly antenna (3), source electrode (4), drain electrode (5), dielectric layer (6) and grid (7), its characterized in that:

the structure of the detector is as follows from bottom to top: the first layer is a substrate (1), the second layer is black arsenic phosphorus (2), a butterfly antenna (3) lapped on the black arsenic phosphorus, a source electrode (4) and a drain electrode (5) connected with the antenna, the third layer is a dielectric layer (6), and the fourth layer is a grid electrode (7);

the substrate (1) is intrinsic silicon with silicon dioxide;

the black arsenic phosphorus (2) is multilayer black arsenic phosphorus, and the thickness is 20 to 40 nanometers;

the butterfly antenna (3), the source electrode (4) and the drain electrode (5) are respectively provided with two metal layers, the lower metal layer is titanium, and the upper metal layer is gold;

the dielectric layer (6) is hafnium oxide;

the grid (7) is provided with two metal layers, wherein the lower metal layer is titanium, and the upper metal layer is gold.

2. A method for preparing the tunable room temperature black arsenic phosphorus terahertz detector as claimed in claim 1, characterized by comprising the following steps:

1) preparing silicon dioxide on intrinsic silicon as a substrate (1) by a thermal oxidation method;

2) preparing and transferring black arsenic phosphorus (2) to the surface of a substrate (1) by a mechanical stripping method;

3) preparing a source electrode (4) and a drain electrode (5) of the butterfly antenna (3) by adopting an electron beam exposure technology and combining electron beam deposition and a traditional stripping process;

4) growing a dielectric layer (6) by adopting an atomic layer deposition process;

5) and (3) preparing a grid (7) on the dielectric layer (6) by electron beam exposure and electron beam deposition technology to finish the preparation of the adjustable room temperature black arsenic phosphorus terahertz detector.

Technical Field

The invention relates to an adjustable room-temperature black arsenic phosphorus terahertz detector and a preparation method thereof, in particular to a field effect tube prepared by combining a black arsenic phosphorus material and a butterfly antenna, wherein the characteristics of adjustable black arsenic phosphorus band gap, high carrier mobility and in-plane anisotropy are utilized to realize quick response, and the butterfly antenna is utilized to realize high-efficiency coupling of a terahertz electric field so as to realize high response rate. The working principle of the terahertz frequency mixing antenna is that a high-local-area and enhanced terahertz frequency mixing electric field is realized through the asymmetric high-efficiency terahertz antenna, and a response signal is generated. The detector has the characteristics of high speed, wide frequency, high response rate and the like, can realize double regulation and control of source-drain bias voltage and gate voltage, and lays a foundation for realizing large-scale application of the room-temperature terahertz detector.

Background

The terahertz wave has a frequency ranging from 0.1THz to 10THz, a wavelength ranging from 3 mm to 30 μm, and a photon energy characteristic value of 4 millielectron volts. This characteristic energy range is matched to the vibrational and rotational energy of the molecule and is much smaller than the bandgap of common semiconductors. The characteristics of terahertz waves in the aspects of transmission, scattering, absorption and the like are greatly different from those of visible light, infrared and microwave, and a large utilization space is provided for spectroscopy, imaging, communication and the like. The terahertz technology is located in the crossing field of electronics and photonics, and the two disciplines are fused and developed, so that the technical level of the terahertz technology is greatly improved. However, currently, the research and development of terahertz is still in the initial stage, and a high-power and high-stability terahertz source, a high-sensitivity and wide-spectrum terahertz detector and a high-speed and high-efficiency terahertz modulator are relatively rare, so that they are called "terahertz blanks (THz gaps)".

The unique position of terahertz waves in the electromagnetic spectrum determines that it has special properties that many other bands do not have: (1) the photon energy of terahertz radiation is only millielectron volt generally and is far lower than the chemical bond energy of common substances, so that the terahertz wave can overcome the ionization destructiveness of X rays on a plurality of substances, and is suitable for security inspection of airports, stations and other public places. (2) The intrinsic vibration frequency of a plurality of substances is in the terahertz waveband, the substances have the characteristics of terahertz fingerprint spectrum, contain rich physical and chemical information, and can be used for identifying and detecting the substances by utilizing the terahertz waves. (3) The terahertz radiation has strong penetrating power and can be used for quality monitoring and perspective imaging of a non-transparent object. (4) The terahertz wave has the advantages of large bandwidth, high wireless transmission rate, low background noise and difficulty in interference, and has great application potential in the field of wireless communication. In a word, terahertz waves are between microwaves and infrared in an electromagnetic spectrum, have a plurality of excellent characteristics, and have wide application prospects in the fields of safety inspection, substance identification, medicine, nondestructive imaging, wireless communication and the like, so that the development of the detection technology of terahertz waves has great significance.

The development of a terahertz detection device which is high in speed, high in sensitivity and capable of working at room temperature is an important breakthrough for realizing the terahertz technology, and the improvement of the coupling capacity of light and the device and the photoelectric conversion efficiency is a key subject of terahertz detection. Current commercial terahertz detectors include pyroelectric terahertz detectors, bolometers, and schottky diodes. Generally, the response speed of the pyroelectric detector is relatively slow; the Schottky diode has lower working frequency and complex process; the bolometer needs to operate at low temperature. In addition, the quantum well terahertz detector is easily influenced by thermal disturbance; the quantum efficiency of the field effect transistor terahertz detector is low. Therefore, developing new materials and exploring new principles to realize terahertz detection become hot spots in the field of terahertz detection, and the development of terahertz detection is receiving wide attention. The black arsenic phosphorus material has the characteristics of adjustable band gap, high electron mobility, in-plane anisotropy, simple growth process and the like; the asymmetric butterfly antenna can realize high-efficiency coupling of the terahertz electric field. The combination of the two provides a new alternative for developing a novel terahertz detection technology.

Disclosure of Invention

The invention provides an adjustable room-temperature black arsenic phosphorus terahertz detector and a preparation method thereof, which realize rapid and high-response-rate room-temperature terahertz detection. The working principle of the terahertz frequency mixing antenna is that a high-local-area and enhanced terahertz frequency mixing electric field is realized through the asymmetric high-efficiency terahertz antenna, and a response signal is generated. The detector has the advantages of high speed, wide frequency, high sensitivity and the like, can realize dual regulation and control of source-drain bias voltage and grid voltage, and lays a foundation for realizing large-scale application of the room-temperature terahertz detector.

The invention relates to an adjustable room temperature black arsenic phosphorus terahertz detector and a preparation method thereof, wherein the structure of the detector is as follows from bottom to top: the first layer is a substrate 1, the second layer is black arsenic phosphorus 2, a butterfly antenna 3 lapped on the black arsenic phosphorus, a source electrode 4 and a drain electrode 5 connected with the antenna, the third layer is a dielectric layer 6, and the fourth layer is a grid electrode 7;

the substrate 1 is intrinsic silicon and silicon dioxide covered on the intrinsic silicon;

the black arsenic phosphorus 2 is multilayer black arsenic phosphorus, and the thickness is 20-40 nanometers;

the butterfly antenna 3, the source electrode 4 and the drain electrode 5 are provided with two metal layers, the lower metal layer is titanium, and the upper metal layer is gold;

the dielectric layer is hafnium oxide;

the grid 7 has two metal layers, the lower metal layer is titanium, and the upper metal layer is gold.

The invention relates to an adjustable room temperature black arsenic phosphorus terahertz detector and a preparation method thereof, wherein the preparation of the device comprises the following steps:

1) preparing silicon dioxide on intrinsic silicon as a substrate 1 by a thermal oxidation method;

2) preparing and transferring black arsenic phosphorus 2 to the surface of the substrate 1 by a mechanical stripping method;

3) preparing a source electrode 4 and a drain electrode 5 of the butterfly antenna 3 by adopting an electron beam exposure technology and combining electron beam deposition and a traditional stripping process;

4) growing a dielectric layer 6 by adopting an atomic layer deposition process;

5) and preparing a grid 7 on the dielectric layer 6 by electron beam exposure and electron beam deposition technology to finish the preparation of the adjustable room temperature black arsenic phosphorus terahertz detector.

The invention has the advantages that:

1) the intrinsic silicon is adopted as the substrate, the reflection of the substrate to terahertz is obviously reduced, and the photoelectric coupling efficiency and the response sensitivity of the device are improved.

2) The black arsenic phosphorus is used as a conductive channel material, has the advantages of adjustable band gap, high electron mobility, in-plane anisotropy, low growth cost and the like, and can be used for broadband and high-speed terahertz detection.

3) By adopting the butterfly antenna structure, the local enhancement of the terahertz electric field is realized, the coupling capability of the terahertz wave and the detector is improved, and the photoelectric conversion efficiency and the detection rate of the detector are enhanced.

Drawings

FIG. 1 is a schematic side view of a tunable room temperature black arsenic phosphorus terahertz detector according to the present invention;

in the figure: 1 silicon substrate, 2 black arsenic phosphorus, 3 butterfly antennas, 4 source electrodes, 5 drain electrodes, 6 dielectric layers and 7 grid electrodes.

FIG. 2 is a schematic diagram of an experimental device for testing a controllable room-temperature black arsenic phosphorus terahertz detector;

FIG. 3 is a response waveform diagram of the adjustable room temperature black arsenic phosphorus terahertz detector at the working frequency of 1kHz and 0.12THz at room temperature;

FIG. 4 is a response waveform diagram of the adjustable room temperature black arsenic phosphorus terahertz detector under the working frequencies of 1kHz chopping frequency and 0.3THz at room temperature;

FIG. 5 is a response diagram of the controllable room temperature black arsenic phosphorus terahertz detector under bias control;

fig. 6 is a response diagram of the adjustable room-temperature black arsenic phosphorus terahertz detector under the control of the gate voltage.

The specific implementation mode is as follows:

the following detailed description of embodiments of the invention refers to the accompanying drawings in which:

the invention provides an adjustable room temperature black arsenic phosphorus terahertz detector and a preparation method thereof, which realize rapid and high-sensitivity room temperature terahertz detection. The working principle of the terahertz frequency mixing antenna is that a high-local-area and enhanced terahertz frequency mixing electric field is realized through the asymmetric high-efficiency terahertz antenna, and a response signal is generated. The detector has the characteristics of high speed, wide frequency, high sensitivity and the like, can realize double regulation and control of source-drain bias voltage and gate voltage, and provides a prototype device for realizing large-scale application of the room-temperature terahertz detector.

The method comprises the following specific steps:

1. substrate selection

Intrinsic silicon and overlying silicon dioxide are selected as the substrate.

2. Black arsenic phosphorus preparation and transfer

Transferring black arsenic phosphorus to the surface of the substrate by mechanical stripping transfer;

3. preparing a butterfly antenna, a source electrode and a drain electrode by adopting an electron beam exposure technology and combining electron beam deposition and a traditional stripping process;

4. growing a dielectric layer by adopting an atomic layer deposition process, wherein the material of the dielectric layer is hafnium oxide;

5. and preparing a grid on the dielectric layer by electron beam exposure and electron beam deposition technology to finish the preparation of the adjustable room temperature black arsenic phosphorus terahertz detector.

7. And carrying out photoelectric response test on the prepared black arsenic phosphorus terahertz detector. As shown in fig. 3, the thz source is a continuous wave system composed of a microwave source, a frequency multiplier and an amplifier, and the frequency is between 0.02 and 0.3 thz. Terahertz radiation is irradiated on the detection device, a photocurrent signal generated by the detection device is amplified through a current amplifier (SR570) and respectively input into an oscilloscope and a phase-locked amplifier (SR830), and a chopping signal built in a microwave source (E8257D) is used as a reference signal and respectively input into the oscilloscope and the phase-locked amplifier. The device shows ultrahigh response rate and rapid detection capability in the test process.

a) When the thickness of the black arsenic phosphorus is 20 nanometers, the channel length is 6 micrometers, and the power density of the terahertz source is 1 milliwatt per square millimeter, the photocurrent of 12 nanoamperes can be realized.

b) When the thickness of the black arsenic phosphorus is 30 nanometers, the channel length is 6 micrometers, and the power density of the terahertz source is 1 milliwatt per square millimeter, the photocurrent of 21 nanoamperes can be realized.

c) When the thickness of the black arsenic phosphorus is 40 nanometers, the length of a channel is 6 micrometers, and the power density of the terahertz source is 1 milliwatt per square millimeter, 35 nanoamperes of photocurrent can be realized.

When the structural parameters of the detector are changed within a certain range, the room-temperature black arsenic phosphorus terahertz detector has good detection performance, and test results show that the response time of the device can be prolongedThe response rate can reach 100V/W at 0.12THz, and the noise equivalent power reaches 200pW/Hz^0.5And the performance regulation and control under bias voltage and grid voltage are realized, the terahertz wave can be effectively detected at room temperature, and the terahertz wave detector has a wide application prospect in the field of terahertz detection.