Method for preparing enhanced GaN field effect device

Abstract

The invention provides a method for preparing an enhanced GaN field effect device structure. By inserting a layer of P-type two-dimensional semiconductor material under a gate metal, two-dimensional electron gas in a channel under a gate can be effectively depleted, and thus an enhanced GaN field effect device is prepared. The P-type two-dimensional semiconductor material of a contact region outside the lower part of the gate is etched and removed by using oxygen plasma, the contact resistance can be effectively reduced, and the device performance is improved. At the same time, by controllingan etching time and oxygen plasma concentration, an oxide film can be formed by a potential barrier layer by using the oxygen plasma, and the gate leakage of the device is reduced.

Description

technical field [0001] The invention relates to the field of manufacturing semiconductor devices, in particular to a method for preparing an enhanced gallium nitride field effect device. Background technique [0002] GaN materials have the characteristics of large band gap, high critical breakdown electric field, and high thermal conductivity, and have broad application prospects in broadband communications, power electronics, and other fields. [0003] Due to the spontaneous polarization and piezoelectric polarization effects at the interface between gallium nitride (GaN) and aluminum gallium nitride (AlGaN) heterojunction, the two-dimensional electron gas concentration is very high (>1E13cm -2 ), which makes GaN FETs [here FETs refer to HEMT (High Electron Mobility Transistor) devices] have very low on-resistance and switching delay. However, the high concentration of two-dimensional electron gas at the AlGaN / GaN heterointerface makes GaN FETs usually depletion-mode de...

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Problems solved by technology

[0005] However, due to the inherent limitations of these methods, such as difficult operation and poor repeatability, it is difficult for the above methods to be widely used.

For example, the etching process of the concave gate groove is difficult to control accurately, and at the same time, it will damage the surface of the barrier layer and cause the problem of current collapse.

; F-based ion implantation will cause lattice damage, which will bring a series of problems of poor long-term reliability; growing a single layer of p-GaN or p-AlGaN on the gate is a feasible method, but P-type nitride materials are usually used dry Etching is easy to form damage on the surface of the barrier layer, and the consistency of the etching process is poor

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