A gan field effect transistor with source-connected p-buried layer and drain field plate

Abstract

The invention discloses a GaN field effect transistor with a source-connected P buried layer and a drain field plate, comprising a gate, a source region, a gate dielectric layer, a passivation layer, a barrier layer, a channel layer, and a low-concentration trap-doped impurity buffer layer, high-concentration trap-doped buffer layer, P-type buried layer connected to the source, and drain field plate; the P-type buried layer connected to the source is located in the low-concentration trap-doped buffer layer, and the drain field plate is located passivation layer and gate extension. When the transistor of the present invention works at off-state high voltage, the P-type buried layer is connected to the drain to fully deplete the carriers in the channel and the buffer layer, thereby reducing the leakage current in the buffer layer and simultaneously modulating the gate-drain electric field distribution. On the basis that the P-type buried layer is connected to the drain, the drain field plate can further modulate the electric field at the drain end, and finally make the device with this structure better than the traditional pure gate field plate AlGaN / GaN insulated gate field effect transistor. Visible improvement.

Description

technical field [0001] The invention relates to a semiconductor power device for high withstand voltage, in particular to a voltage-resistant AlGaN / GaN insulated gate field-effect transistor with a source-connected P-type buried layer and a drain field plate. Background technique [0002] With the continuous development of the world economy, energy consumption continues to increase, non-renewable energy oil reserves are less and less, and the awareness of environmental protection crises in various countries is gradually increasing. In order to reduce the waste of electric energy in power conversion and control of power electronic systems The energy conversion efficiency of the enhancement mode power transistor, the core component in the power electronic system, has been receiving much attention. However, in the power electronic systems of various countries, the enhanced power switching devices used are still mainly Si-based MOSFETs and IGBTs. After years of development, the...

AI Technical Summary

Problems solved by technology

The physical properties of the wide bandgap GaN material and the Si substrate are very different, such as the lattice constant and the thermal expansion coefficient do not match, which makes the heteroepitaxial growth of the GaN buffer layer on the silicon wafer inevitably produce lattice mismatch and Dislocations, while the stresses caused by the lattice constant and thermal expansion coefficient mismatch in the structure can also damage the reliability of the device, and finally in the GaN buffer layer can generate up to 10 10 cm -3 Defects

Due to the doping of impurities and point defects, the grown GaN is basically n-type doped, and the background leakage current is relatively large, which will easily lead to the deterioration of the performance of the device, which may cause premature breakdown of the device.

Images