Method for producing grooved gate enhanced HEMT device based on CMP etching technology

Abstract

The invention discloses a method for producing a grooved gate enhanced HEMT device based on a CMP etching technology. The method comprises the following steps of: arranging a mask on an epitaxial wafer for manufacturing the HEMT device, and exposing a gate region of a barrier layer from the mask; and polishing the surface of the side, provided with the mask, of the epitaxial wafer, wherein the adopted polishing solution can selectively corrode the barrier layer till that a groove structure matched with the grid electrode is formed in the barrier layer. By adopting a chemical polishing mode, the barrier layer in the epitaxial structure of the HEMT device can be selectively etched without damage so as to form the groove structure matched with the grid electrode, the process is simple, the cost is low, the controllability and the repeatability are high, the etching damage of the device structure can be effectively reduced, the lower surface roughness of the grid electrode is smaller, the reliability of the device is remarkably improved, the device has the advantages of a large saturation current, a small on-resistance and good uniformity, and industrial large-scale production is facilitated.

Description

technical field [0001] The invention belongs to the technical field of semiconductor devices, and relates to a method for manufacturing an enhanced HEMT device, in particular to a method for preparing a groove gate enhanced HEMT device based on CMP (chemical mechanical polishing) etching technology and a groove gate enhanced HEMT device. Background technique [0002] As an important third-generation semiconductor material, GaN material has excellent characteristics such as large band gap, high breakdown field strength, and high electron saturation velocity, which makes GaN-based power electronic devices perform better than traditional Si in many aspects. base device. For example, GaN HEMT devices can meet the requirements of high frequency, high power and high efficiency. [0003] GaN HEMT devices can be divided into enhancement type according to whether the threshold voltage is greater than zero (V th >0) and depletion mode (V th <0) two kinds. Conventional HEMT ...

AI Technical Summary

Problems solved by technology

The first solution is to use ICP (Inductively Coupled Plasma) technology to etch GaN materials with Cl-based gases. For GaN and AlGaN, the etching selection ratio is small, the etching process is difficult to control, and the repeatability is poor. Moreover, the damage caused by dry etching and the high-concentration interface state will lead to serious current collapse, which will greatly reduce the performance of the device.

The second solution is to use a hard mask to thermally oxidize AlGaN, and then produce grooves by etching with an alkaline solution. For example, you can refer to CN104167362A and CN103258739A, but the repeatability of this solution is poor, and the uniformity is not good for large-scale products. Ideal, not conducive to industrial production

The third solution is to first use oxygen plasma treatment and then etch, this process is repeated dozens of times, and the GaN interface of the groove and the self-stop layer can be obtained, but this solution takes a long time and the process is complicated

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