Preparation method of enhanced AlGaN/GaN high-electron mobility transistor

Abstract

The invention provides a preparation method of an enhanced AlGaN / GaN high-electron mobility transistor. According to the method, a GaN or AlN nucleating layer, a GaN buffer layer, a GaN channel layer, a AlN insert layer, a AlGaN barrier layer and a InGaN cap layer are grown on a substrate sequentially; a source and a drain are fabricated on the AlGaN barrier layer; a grid is fabricated on the InGaN cap layer; and the enhanced AlGaN / GaN high-electron mobility transistor can be obtained. According to the preparation method of the enhanced AlGaN / GaN high-electron mobility transistor of the invention, the InGaN cap layer contains a large number of In vacancies; since the In vacancies can absorb electrons, the whole cap layer presents electronegativity; the energy level of the conduction band of the barrier layer is increased; and therefore, the two-dimensional electron gas of a channel can be depleted, and the enhancement of the device can be realized, the difficulty that a traditional P type cap layer is difficult to realize high-concentration p doping can be eliminated, and the operability of the preparation of the device is enhanced.

Description

technical field [0001] The invention belongs to the field of semiconductors, in particular to a preparation method of an enhanced AlGaN / GaN high electron mobility transistor (HEMT). Background technique [0002] As the third-generation wide-bandgap semiconductor material, GaN has become a current research hotspot. GaN has the characteristics of large band gap, high critical breakdown electric field, and high electron saturation drift rate, and has unique advantages in the preparation of high-power, high-frequency, high-speed, and small-volume semiconductor power devices. [0003] GaN-based power electronic devices represented by AlGaN / GaN, due to their own spontaneous polarization effect and piezoelectric polarization effect, will generate a large amount of two-dimensional electron gas at the heterojunction interface, and its concentration can reach 1013cm-2 Order of magnitude, electron mobility 2000cm 2 / V·s or more. These properties lead to the advantages of AlGaN / GaN-b...

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Problems solved by technology

However, these methods have relatively large defects in process and device performance. For example, the concave gate etching process is difficult to control accurately, and the etching damage introduced at the same time is relatively large, which will cause current collapse and deteriorate the reliability of the device; fluorine ion implantation It will also bring a series of stability problems; due to the self-compensation effect and the high activation energy of the acceptor impurity in the growth of the p-type cap layer, the incorporation efficiency of the acceptor dopant atoms is low, and it is difficult to achieve a p-type with a high doping concentration. cap growth

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