Terahertz kinetic inductance bolometer, preparation method thereof and terahertz detection system

Patent metadata

Field	Value
Publication number	US-12540858-B2
Application number	US-202318383439-A
Country	US
Kind code	B2
Filing date	Oct 24, 2023
Priority date	Jun 26, 2023
Publication date	Feb 3, 2026
Grant date	Feb 3, 2026

Abstract

Disclosed in the present invention is a terahertz kinetic inductance bolometer, including a superconducting thin film layer, a terahertz antenna, a cutoff layer and a Si substrate, wherein the superconducting thin film layer and the terahertz antenna are respectively deposited on the cutoff layer, and the cutoff layer is deposited on the Si substrate; the superconducting thin film layer includes a superconducting feeder line, an inter-digital capacitor and an inductor coil; the inter-digital capacitor is connected with the inductor coil in parallel to form an oscillation circuit; the terahertz antenna is adjacent to the inductor coil and is used to convert a received terahertz signal into heat so that the inductor coil produces an inductance change; a resonance frequency in the inter-digital capacitor changes through the inductance change; and the superconducting feeder line receives the varying resonance frequency, through which an light intensity of the terahertz signal can be obtained to complete the detection of the terahertz signal. The terahertz kinetic inductance bolometer can detect the terahertz signal accurately and is less affected by the temperature. The present invention also provides a preparation method of the terahertz kinetic inductance bolometer and a terahertz detection system.

First claim

The invention claimed is:

1 . A terahertz kinetic inductance bolometer, comprising a superconducting thin film layer, a terahertz antenna, a cutoff layer and a Si substrate, wherein the superconducting thin film layer and the terahertz antenna are respectively deposited on the cutoff layer, and the cutoff layer is deposited on the Si substrate;
the superconducting thin film layer comprises a superconducting feeder line, an inter-digital capacitor and an inductor coil; the inter-digital capacitor is connected with the inductor coil in parallel to form an oscillation circuit; the terahertz antenna is adjacent to the inductor coil and is used to convert a received terahertz signal into heat so that the inductor coil produces an inductance change; a resonance frequency in the inter-digital capacitor changes through the inductance change; and the superconducting feeder line is coupled with the inter-digital capacitor to receive the varying resonance frequency, through which an light intensity of the terahertz signal can be obtained to complete the detection of the terahertz signal.

2 . The terahertz kinetic inductance bolometer according to claim 1 , wherein the cutoff layer comprises a surround module, a thermal connection bridge and an island module; and the surround module surrounds the island module, and the surround module and the island module are connected through the thermal connection bridge; and
the superconducting feeder line and the inter-digital capacitor are located at the top of the surround module, the inductor coil and the terahertz antenna are located at the top of the island module, and the Si substrate is located at the bottom of the surround module, so that the inductor coil and the terahertz antenna at the top of the island module are isolated from the Si substrate at the bottom of the surround module and the superconducting feeder line and the inter-digital capacitor at the top of the surround module.

3 . The terahertz kinetic inductance bolometer according to claim 1 , wherein the cutoff layer comprises a SiO 2 layer and a SiN x layer, and the SiO 2 layer is deposited on the Si substrate, and the SiN x layer is located on the SiO 2 layer, wherein x is 1 4/3.

4 . The terahertz kinetic inductance bolometer according to claim 3 , wherein the thickness of the SiO 2 layer is 100-200 nm, and the thickness of the SiN x layer is 300-2000 nm.

5 . The terahertz kinetic inductance bolometer according to claim 1 , wherein the material of the superconducting thin film layer is niobium nitride, niobium titanium nitride or titanium nitride.

6 . The terahertz kinetic inductance bolometer according to claim 1 , wherein the material of the terahertz antenna is titanium-tungsten alloy, aluminum-manganese alloy or bismuth.

7 . A preparation method of the terahertz kinetic inductance bolometer according to claim 1 , comprising:
(1) SiO 2 and SiN x double-layers are respectively deposited on both sides of a double-cast silicon substrate, namely, A and B surfaces, and a superconducting metal layer is grown on the SiO 2 and SiN x double-layer on the A surface by magnetron sputtering; (2) on the surface of the superconducting metal layer, a circuit of the superconducting thin film layer is exposed through photoresist by an lithography machine, and the superconducting thin film layer is obtained by inductively coupled plasma (ICP) etching the superconducting metal layer; (3) the remaining photoresist in step (2) is removed; the photoresist is used again to expose a circuit of the terahertz antenna on the surfaces of the SiO 2 and SiN x double layer and the superconducting thin film layer by using the lithography machine; metal of the terahertz antenna is deposited on the surface of the photoresist and exposed SiO 2 and SiN x double-layer by using a measurement and control sputtering technique; and the remaining photoresist is removed by a stripping method to obtain the terahertz antenna; (4) the photoresist is used again to expose a pattern of the cutoff layer on the surface of the SiO 2 and SiN x double-layer on the A surface by using the lithography machine, and the cutoff layer is obtained by etching, and the residual photoresist is removed; (5) a vehicle wafer is obtained; protective wax on the cutoff layer, the terahertz antenna and the superconducting thin film layer is bonded with the protective wax on the vehicle wafer; (6) the SiO 2 and SiN x double-layer on the B surface of the double-cast silicon substrate is removed to expose the double-cast silicon substrate; the photoresist is used to expose the island module on the B surface of the double-cast silicon substrate by the lithography machine; the exposed double-cast silicon substrate is etched by a deep silicon reactive ion etching technique so as to obtain the Si substrate; and the remaining photoresist is removed; and (7) the terahertz kinetic inductance bolometer is obtained by removing the protective wax with organic solvent.

8 . The preparation method of the terahertz kinetic inductance bolometer according to claim 7 , wherein the superconducting metal layer is grown by the magnetron sputtering on the SiO 2 and SiN x double-layer on the A surface; the superconducting metal is NbN; and the process parameters of the magnetron sputtering are as follows: an air pressure is 1-10 mTorr, power is 50-500W, and a proportion of N 2 and Ar gas is 5%-50%.

9 . The preparation method of the terahertz kinetic inductance bolometer according to claim 7 , wherein the measurement and control sputtering technique is used to deposit the metal of the terahertz antenna on the surface of the photoresist and the exposed SiO 2 and SiN x double-layer surface; the metal of the terahertz antenna is TiW alloy; and the process parameters of the measurement and control sputtering technique are as follows: an air pressure is 1-10 mTorr and power is 50-500W.

10 . A terahertz detection system, comprising a plurality of terahertz kinetic inductance bolometers according to claim 1 , wherein the plurality of terahertz kinetic inductance bolometers are arranged in an array; the plurality of terahertz kinetic inductance bolometers are divided into a plurality of groups; the plurality of terahertz kinetic inductance bolometers in each group share the superconducting feeder line for coupling; and the size of the inter-digital capacitance of each terahertz kinetic inductance bolometer is adjusted so that each terahertz kinetic inductance bolometer has a different initial resonance frequency, which can distinguish a region where each terahertz kinetic inductance bolometer is located, and then can simultaneously monitor an intensity change of a terahertz signal in the region where each terahertz kinetic inductance bolometer is located.

Assignees

• Zhejiang Lab

Inventors

• Zhang Xiaohang
• Yang Lihui
• Song Yanru
• Yu Shiling
• Yan Xiaomi
• Zhu Hongli
• Hong Yue
• Mu Tangjie
• Chen Zhiwei
• Duan Ran
• Zhao Zhifeng
• Feng Yi
• Li Di

Classifications

• G01J2005/208

  superconductive · CPC title

• G01J5/22 Primary

  Electrical features thereof · CPC title

• G01J5/0837

  Microantennas, e.g. bow-tie · CPC title

• G01J5/20

  using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices · CPC title

• G01J5/46 Primary

  using radiation pressure or radiometer effect · CPC title