Method for manufacturing variant barrier gallium nitride FET

Abstract

The invention provides a method for producing variant potential barrier gallium nitride field effect tube, which comprises the following steps: growing a nucleation layer, an AlGaN buffer layer and a GaN channel layer on a substrate; growing an AlN isolating layer and an AlGaN barrier layer; coating a thick GaN cap layer on the AlGaN barrier layer to increase the potential-barrier height; thinning the GaN cap layer except for the part below the grate by using chlorine-based inductively coupled plasma dry corrosion process to increase the electron gas density of the underside channel and weaken the strong field peak; performing photoetching corrosion and making a source electrode and a drain electrode on the corroded AlGaN barrier layer, to reduce the ohmic contact resistance by using the thin potential barrier and high electron gas density; and making variant potential barrier field effect tube. The invention has the advantages that the grid electrode can be formed directly on the GaN cap layer without channeling, thereby significantly reducing the gate current and improving the reliability; the fabrication of field plate electrode is omitted to simplify the process, reduce the parasitic capacitance, and increase the gain; and the invention facilitates the research of millimeter wave high-frequency apparatuses.

Description

technical field [0001] The invention relates to a method for manufacturing a semiconductor device, in particular to a method for manufacturing a variable barrier GaN field effect transistor, in particular to a method for manufacturing a GaN field effect transistor with low gate current and high reliability. It belongs to the technical field of semiconductor devices. Background technique [0002] The strong polarized charge and large energy band order on the AlGaN / GaN heterointerface generate a high-density two-dimensional electron gas, which improves the output power of GaN field effect transistors by an order of magnitude compared with GaAs field effect transistors. However, a large number of experimental studies have found that the stability of this high-power FET is very poor. In high-power radio frequency work, there is a large forward gate voltage, which generates a large forward gate current, which causes the Schottky barrier to degenerate. In addition, a strong elec...

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Problems solved by technology

However, these dielectric layers increase the distance between the gate electrode and the channel, reduce the transconductance and pinch-off voltage, and enhance the electric field when the channel is pinched off, and the generated high-energy hot electrons jump out of the channel, resulting in current collapse and Device performance degradation

These conflicting requirements greatly increase the difficulty of optimally designing device heterostructures

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