4h-sic metal-semiconductor field-effect transistor with lightly doped gate edge and drain side parts

Abstract

The invention discloses a 4H-SiC metal-semiconductor field effect transistor with light doping on the drain side of the gate edge, including a 4H-SiC semi-insulating substrate, a P-type buffer layer, an N-type channel layer, and an N-type channel from bottom to top. Both sides of the upper surface of the channel layer are provided with a source cap layer and a drain cap layer, the upper surface of the source cap layer is provided with a source electrode, the upper surface of the drain cap layer is provided with a drain electrode, and the bottom of the N-type channel layer is close to the source One side of the pole cap layer is provided with a gate electrode, and a lightly doped region is formed at the bottom of the N-type channel layer under the gate of a part of the gate electrode and between part of the gate and drain. The vertical line is the axis of symmetry and the structure is axisymmetric. The invention can alleviate the electric field concentration effect on the drain side of the gate edge to optimize the electric field and current on the drain side of the gate edge, thereby suppressing breakdown; it can alleviate the hot electron charging effect, so as to reduce the generation of interface states and suppress the decline of device performance, thereby Improve device life.

Description

technical field [0001] The invention relates to the technical field of field effect transistors, in particular to a 4H-SiC metal-semiconductor field effect transistor with light doping on the drain side of the gate edge. Background technique [0002] SiC materials have outstanding material and electrical properties such as wide band gap, high breakdown electric field, high saturated electron migration velocity, and high thermal conductivity, making them suitable for high-frequency and high-power device applications, especially high temperature, high voltage, aerospace, satellite, etc. It has great potential in high-frequency high-power device applications in harsh environments. In SiC allomorphs, the electron mobility of 4H-SiC with hexagonal close-packed wurtzite structure is nearly three times that of 6H-SiC, so 4H-SiC materials are used in high-frequency and high-power devices, especially in metal-semiconductor fields. Effect transistor (MESFET) occupies a major position...

AI Technical Summary

Problems solved by technology

However, the electric field concentration effect and hot electron charging effect on the drain side of the gate edge have not been effectively improved, which makes the device easy to be broken down, and the life is greatly affected, which limits the working environment and reliability of the device

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