Preparation method of terahertz detector based on suspended micro-bridge process

Abstract

The invention discloses a preparation method of a terahertz detector based on a suspended micro-bridge process, which comprises the following steps of: performing magnetron sputtering on a Si and SiO2double-layer substrate to grow an Nb5N6 thermosensitive film; spin-coating photoresist on the Nb5N6 thin film, drawing an antenna pattern in a deep ultraviolet exposure mode, and stripping an electrode after the Au thin film grows in a magnetic control mode; spin-coating photoresist on the Nb5N6 thin film, drawing a micro-bridge pattern in a deep ultraviolet exposure mode, and etching redundant Nb5N6 through a reactive ion etching method to form an Nb5N6 thin film micro-bridge; AZ4620 photoresist is spin-coated on the surface of a substrate, windows are formed on two sides of a micro-bridge in an ultraviolet photoetching mode, SiO2 in the windows is etched by a wet etching method, part of Si in the windows is etched firstly by a reactive ion step-by-step etching method, and then the lowerpart of the micro-bridge is transversely etched to form an air cavity. According to the invention, the stability of the process and the yield of the terahertz array detector are improved.

Description

technical field [0001] The invention relates to a preparation method of a terahertz detector with a suspended microbridge technology, and belongs to the technical field of terahertz detector preparation. Background technique [0002] The microbolometer (Bolometer) works at room temperature and uses the characteristics of the resistivity of the thermosensitive material to change with temperature to sense the terahertz radiation. It has the advantages of simple manufacturing process, high sensitivity, and easy integration with the readout circuit to form a large-scale Array, with advantages such as wide frequency detection range, is one of the most widely used thermal detectors at present. The suspended microbolometer is composed of a suspended heat-sensitive film bridge deck, bridge legs, bridge piers, electrodes, readout circuits and reflection layers. When the suspended heat-sensitive film material bridge receives terahertz radiation, its resistance changes, and the power ...

AI Technical Summary

Problems solved by technology

[0005] Second, the etching time is difficult to grasp

Increasing the etching time will not only consume the mask material, but also accumulate impurities generated during the etching process in the chamber, and a passivation layer will appear on the etching surface of the device, making the device surface unable to be further etched

[0006] Third, it is difficult to balance the etching power and etching time

Moderately increasing the etching power can increase the etching rate and save etching time, but it will also increase the temperature of the device and accelerate the denaturation of the photoresist, and reducing the etching rate will take more etching time

Images