CN109541712B

CN109541712B - Metal gate MOSFET terahertz detector based on periodic grating gate

Info

Publication number: CN109541712B
Application number: CN201811456308.1A
Authority: CN
Inventors: 马建国; 周绍华
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2018-11-30
Filing date: 2018-11-30
Publication date: 2020-07-28
Anticipated expiration: 2038-11-30
Also published as: CN109541712A; LU101402B1

Abstract

The invention discloses a terahertz detector based on a metal gate MOSFET (metal-oxide-semiconductor field effect transistor) of a periodic grating gate, which comprises the metal gate MOSFET, a low-noise preamplifier and a voltage feedback loop, wherein the metal gate MOSFET is provided with the periodic grating gate and various patterns of the metal gate MOSFET; the grid electrode of the metal grid MOSFET is used for receiving a terahertz signal, the grid electrode of the metal grid MOSFET is connected with a first bias voltage source through a first bias resistor, the source electrode of the metal grid MOSFET is grounded, and a first blocking capacitor is connected between the drain electrode of the metal grid MOSFET and the positive input end of the low-noise preamplifier; the positive input end of the low-noise preamplifier is connected with a second bias voltage source through a second bias resistor; the voltage feedback loop comprises a feedback resistor, a grounding resistor, a second blocking capacitor and a third blocking capacitor. According to the terahertz detector, the THz response waveband range is adjusted by adjusting the rasterization structural parameters of the grid, so that the detection sensitivity of the terahertz detector is improved.

Description

Metal gate MOSFET terahertz detector based on periodic grating gate

Technical Field

The invention relates to the technical field of terahertz detectors, in particular to a metal gate MOSFET terahertz detector based on a periodic grating gate.

Background

The terahertz wave is an electromagnetic wave between microwave and infrared light on an electromagnetic spectrum, the frequency of the terahertz wave is about 0.1-10 THz, and the wavelength corresponds to 3 mm-30 mu m. The terahertz technology is one of the leading edge and hot spot fields of current information science and technology research, and has been widely concerned by research institutions in various countries in the world in recent years. Developed countries in the United states, the Japan and the Europe successively evaluate the terahertz technology as ten major technologies for changing the future world and ten major key strategic targets for the national strut technology, and great investment is invested to tamp the international status in the terahertz field. Terahertz has a wide application prospect, and has wide technical application in the fields of astrophysics, material science, biomedicine, environmental science, spectrum and imaging technology, information science and technology and the like. The terahertz technology can remarkably improve the strength of China in the aspects of aerospace, space communication, biomedical treatment, even food detection and the like. The terahertz detector serving as a terahertz application basis is a key component for terahertz security and detection.

Due to the fact that any conductor lead brings about extremely serious parasitic effect in the terahertz frequency band, the performance of most detectors based on III-V/II-VI process is difficult to control, even the detectors do not work, and therefore the practicability of the terahertz detectors is restricted. Development of room temperature terahertz detectors based on CMOS compatible processes is the basis for realizing low-cost and large-scale popularization of terahertz detection and array imaging. However, the existing detectors based on the CMOS compatible process generally have the disadvantages of slow response speed, low sensitivity, high price, and the like, and generally need to work at low temperature, which greatly limits the integrated application and development of the terahertz technology. Therefore, the development of the CMOS compatible room temperature terahertz detector with high responsivity, high sensitivity and low price becomes a problem which needs to be solved urgently in the integration application and development process of the terahertz technology.

Disclosure of Invention

The invention provides a metal gate MOSFET terahertz detector based on a periodic grating gate, which realizes the adjustment of a THz response waveband range by adjusting grating structure parameters (the width, the length, the area, the period and the pattern form of the grating) of the gate, thereby improving the detection sensitivity of the detector; grating structures with adjustable periods and various different pattern forms are introduced to replace the metal gate of the original MOSFET through photoetching, nano-imprinting and regulation and control of artificial microstructure materials, so that metal gate grating prepared from CMOS compatible low-dimensional semiconductor materials (such as nano wires) is realized, the gate and terahertz waves generate resonance, the plasma resonance effect is enhanced, and the response speed of the detector is improved.

The purpose of the invention is realized by the following technical scheme.

The invention relates to a terahertz detector based on a metal gate MOSFET (metal-oxide-semiconductor field effect transistor) of a periodic grating gate, which comprises the metal gate MOSFET with the periodic grating gate and various different pattern forms, a low-noise preamplifier and a voltage feedback loop;

the grid electrode of the metal grid MOSFET is used for receiving a terahertz signal, the grid electrode of the metal grid MOSFET is connected with a first bias voltage source through a first bias resistor, the source electrode of the metal grid MOSFET is grounded, and a first blocking capacitor is connected between the drain electrode of the metal grid MOSFET and the positive input end of the low-noise preamplifier; the positive input end of the low-noise preamplifier is connected with a second bias voltage source through a second bias resistor;

the voltage feedback loop comprises a feedback resistor, a grounding resistor, a second blocking capacitor and a third blocking capacitor, the feedback resistor is connected between the output end and the reverse input end of the low-noise preamplifier, one end of the grounding resistor is connected with the reverse input end of the low-noise preamplifier, the other end of the grounding resistor is grounded through the second blocking capacitor, one end of the third blocking capacitor is connected with the output end of the low-noise preamplifier, and the other end of the third blocking capacitor is grounded.

The first bias voltage source and the first bias resistor are used for providing direct current power supply for the metal gate MOSFET, and the THz response waveband range is adjusted by adjusting the grating structure parameters (the width, the length, the area, the period and the pattern form) of the grid electrode of the metal gate MOSFET.

Compared with the prior art, the technical scheme of the invention has the following beneficial effects:

(1) the invention is based on a silicon-based CMOS (complementary metal oxide semiconductor) process, is convenient to integrate with a back-end circuit, is easy to realize large-scale mass production, and further reduces the cost of the detector.

(2) According to the invention, the THz response waveband range can be adjusted by adjusting the grating structure parameters (the width, the length, the area, the period and the pattern form of the grating) of the grid, so that the sensitivity of terahertz detection is improved, and narrow-band (even dot-frequency) terahertz detection is realized.

(3) The method for rasterizing the metal grid can solve the problems of diffusion and loss of weak terahertz signals in space and plasma excited by the metal structure on the grid in the propagation process.

(4) According to the invention, the grating-like channel is formed in the channel, so that the resonance enhancement between the plasma and the grid plasma in the substrate is realized, and the detection efficiency is improved.

(5) The invention does not need to use an antenna, and can effectively avoid the problems of large loss of the on-chip antenna, low gain and radiation efficiency, large verification difficulty through DRC design rules and the like; the chip area is greatly reduced, and the production cost is greatly reduced.

(6) The invention can utilize the regulation and control functions of the grating on the light resonance principle and the like to enable the grated metal grid to generate resonance with terahertz waves, thereby improving the photoelectric conversion efficiency.

Drawings

FIG. 1 is a schematic diagram of two metal gate MOSFETs with periodically rasterized gate structures and different forms of grating patterns;

fig. 2 is a circuit diagram of a terahertz detector based on a metal gate MOSFET of a periodic grating.

Reference numerals: a Vb1 first bias voltage source, a Vb2 second bias voltage source, an Rb1 first bias resistor, an Rb2 second bias resistor, a C1 first blocking capacitor, a C2 second blocking capacitor, a C3 third blocking capacitor, a Q1 metal gate MOSFET, a Q2 low-noise preamplifier, an Rf feedback resistor, an Rg ground resistor and a GND ground.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

The invention is based on a periodic grating gate metal gate MOSFET terahertz detector, as shown in FIGS. 1 and 2, comprising a metal gate MOSFET Q1 with a periodic grating gate and various different pattern forms thereof, a low noise preamplifier Q2 and a voltage feedback loop.

The grid electrode grading-Gate of the metal grid MOSFET Q1 is used for receiving terahertz signals. The grid grading-Gate of the metal grid MOSFET Q1 is connected with and loaded with a first bias voltage source Vb1 through a first bias resistor Rb1 and used for providing direct current power supply for the metal grid MOSFET Q1, and the THz response waveband range can be adjusted by adjusting the Grating structure parameters (the width, the length, the area, the period and the pattern form) of the grid grading-Gate of the metal grid MOSFET Q1, so that the detection sensitivity of the detector is improved. The first bias voltage source Vb1 is a fixed dc bias voltage source.

The source S of the metal gate MOSFET Q1 is grounded GND, and a first blocking capacitor C1 is connected between the drain D of the metal gate MOSFET Q1 and the positive input end of the low noise preamplifier Q2. The positive input terminal of the low noise preamplifier Q2 is also connected to a bias voltage source Vb2 via a bias resistor Rb 2. The second bias resistor Rb2 and the second bias voltage source Vb2 are used for supplying power to the low-noise preamplifier Q2; the second bias voltage source Vb2 is a fixed direct current bias voltage source.

The voltage feedback loop mainly comprises a feedback resistor Rf, a grounding resistor Rg, a second blocking capacitor C2 and a third blocking capacitor C3. The feedback resistor Rf is connected between the output end and the reverse input end of the low-noise preamplifier Q2, one end of the grounding resistor Rg is connected with the reverse input end of the low-noise preamplifier Q2, the other end of the grounding resistor Rg is grounded GND through a second blocking capacitor C2, one end of the third blocking capacitor C3 is connected with the output end of the low-noise preamplifier Q2, and the other end of the third blocking capacitor C3 is grounded GND. Wherein, the gain of the low noise preamplifier Q2 can be adjusted by changing the resistance values of the feedback resistor Rf and the grounding resistor Rg.

According to the terahertz detection device and the terahertz detection method, the output voltage signal of the metal gate MOSFET terahertz detector based on the periodic grating gate is a direct current voltage signal, the magnitude of the direct current voltage signal is in direct proportion to the radiation intensity of the terahertz signal, and the intensity information of the incident terahertz signal can be obtained according to the magnitude of the output voltage signal of the terahertz detector, so that terahertz detection is realized.

While the present invention has been described in terms of its functions and operations with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise functions and operations described above, and that the above-described embodiments are illustrative rather than restrictive, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined by the appended claims.

Claims

1. A terahertz detector based on a metal gate MOSFET (metal-oxide-semiconductor field effect transistor) with a periodic grating gate and various different pattern forms of the metal gate MOSFET (Q1), a low-noise preamplifier (Q2) and a voltage feedback loop are included;

the gate of the metal gate MOSFET (Q1) is used for receiving a terahertz signal, the gate of the metal gate MOSFET (Q1) is connected with a first bias voltage source (Vb1) through a first bias resistor (Rb1), the source of the metal gate MOSFET (Q1) is Grounded (GND), and a first blocking capacitor (C1) is connected between the drain of the metal gate MOSFET (Q1) and the positive input end of the low-noise preamplifier (Q2); the positive input end of the low-noise preamplifier (Q2) is connected with a bias voltage source (Vb2) through a bias resistor (Rb 2);

the voltage feedback loop comprises a feedback resistor (Rf), a ground resistor (Rg), a second blocking capacitor (C2) and a third blocking capacitor (C3), the feedback resistor (Rf) is connected between the output end and the reverse input end of the low-noise preamplifier (Q2), one end of the ground resistor (Rg) is connected with the reverse input end of the low-noise preamplifier (Q2), the other end of the ground resistor (Rg) is Grounded (GND) through the second blocking capacitor (C2), one end of the third blocking capacitor (C3) is connected with the output end of the low-noise preamplifier (Q2), and the other end of the third blocking capacitor (C3) is Grounded (GND).

2. The terahertz detector based on the metal-gate MOSFET with the periodic grating as claimed in claim 1, wherein the bias voltage source number one (Vb1) and the bias resistor number one (Rb1) are used for providing direct current power supply for the metal-gate MOSFET (Q1), and the adjustment of the THz response wave band range is realized by adjusting the grating structure parameters of the gate of the metal-gate MOSFET (Q1).