algan/gan high electron mobility field effect transistor structure

Abstract

The invention is an AlGaN / GaN high electron mobility field effect transistor structure with polarization modulation of a composite buffer layer, and its structure is from bottom to top along the epitaxial growth direction: single crystal substrate; Alx1Ga1-x1N buffer layer with polarization modulation , Alx2Ga1‑x2N buffer layer; GaN channel layer; AlyGa1‑yN barrier layer. Advantages: It can significantly increase the back barrier height of the buffer layer relative to the channel potential well, reduce the probability of thermal electrons entering the buffer layer from the channel under electrical stress and be captured by deep-level acceptors, and suppress current collapse; It maintains the confinement of the electron gas, reduces the parasitic conductance and leakage current of the buffer layer, and has a higher critical breakdown electric field than the conventional GaN or Al0.05Ga0.95N buffer layer, improving the breakdown characteristics of the device. It is beneficial to improve the power and frequency characteristics of AlGaN / GaN HEMTs in the fields of radio frequency power amplifiers and high-speed power switching devices.

Description

technical field [0001] The present invention relates to an AlGaN / GaN high electron mobility field effect transistor structure, especially an Al x Ga 1-x N compound buffer layer to effectively suppress the current collapse caused by the deep energy level acceptor in the buffer layer and significantly improve the breakdown characteristics of the device, a composite buffer layer polarization modulation AlGaN / GaN high electron mobility field effect transistor structure. Background technique [0002] AlGaN / GaN high electron mobility field effect transistor is a new type of semiconductor electronics that generates a high concentration of two-dimensional electron gas at the heterojunction interface channel based on the unique polarization effect of nitride, and controls the channel switch through the gate voltage. Devices, with high frequency, high power and high temperature resistance characteristics, are widely used in wireless communication base stations, high-speed power switc...

AI Technical Summary

Problems solved by technology

At present, the breakdown voltage of the device is mainly improved by the following technologies: introducing a field plate structure to weaken the electric field measured near the gate to the drain. A more complex process; use AlGaN with a wider bandgap instead of GaN as the channel layer material, and increase the breakdown voltage by increasing the critical breakdown electric field of the channel layer, but at the expense of the mobility of the two-dimensional electron gas of the channel; using conventional Al 0.05 Ga 0.95 The back barrier structure of the N buffer layer can reduce the leakage of the buffer layer and increase the critical breakdown electric field of the buffer layer, but the improvement effect on the breakdown voltage is limited, and it will also reduce the source-leakage current

Images