A kind of surface passivation method of gan-based pin type ultraviolet detector

Abstract

The invention relates to a method for passivating the surface of a GaN-based PIN type ultraviolet detector. The process is as follows: first clean the GaN-based sample and grow a dry etching barrier layer, then apply photoresist, photoetch and etch the barrier layer to Expose the area that needs to be dry etched, and remove the photoresist; then etch the sample with dry etching, requiring the etching depth to be half of the final etching depth, and take out the sample; then spin coat the sample with a layer of photoresist Resist, photolithography and etching the barrier layer to expose the secondary step area, remove the photoresist; then perform secondary etching on the sample, the etching depth is about half of the final etching depth, take out the sample; then remove the surface of the sample successively The barrier layer is left, the damaged layer is etched, and finally a passivation layer is grown on the sample. The present invention forms double steps when preparing the vertical mesa, thereby reducing the step height of the sample, so when the passivation layer grows, the passivation layer is easy to completely cover the surface of the device and the side wall of the step, thereby forming a better passivation effect.

Description

A method for passivating the surface of a GaN-based PIN type ultraviolet detector technical field The invention belongs to the manufacturing technology of semiconductor photodetectors, and relates to a method for passivating the surface of a GaN-based PIN type ultraviolet detector. Background technique In the preparation process of GaN-based PIN-type ultraviolet detectors, in order to lead out electrodes and prepare ohmic contacts on N-type or P-type GaN-based materials, mesa etching is an essential process. The chemical properties of GaN-based materials are stable, and there is no effective wet chemical etching solution available at present, so only dry etching technology can be used to form the steps required by the process. Available dry etching processes include reactive ion etching and low-pressure high-density plasma etching (including electron cyclotron resonance, inductively coupled plasma, etc.). Reactive ion etching is a combination of the physical effect of ion...

AI Technical Summary

Problems solved by technology

In order to solve the problem that it is difficult to manufacture a passivation layer effectively covering the step side wall formed by dry etching in the preparation process of the GaN-based PIN type ultraviolet detector in the prior art, the present invention provides a new GaN-based PIN type ultraviolet detector The passivation method completely covers the step side wall formed by dry etching, which effectively improves the passivation effect

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