4H-SiC metal semiconductor field effect transistor with lightly doped gate edge drain side portion

Abstract

The invention discloses a 4H-SiC metal semiconductor field effect transistor with a lightly doped gate edge drain side portion. The 4H-SiC metal semiconductor field effect transistor comprises a 4H-SiC semi-insulating substrate, a P-type buffer layer and an N-type channel layer from the bottom to top. Two sides of the upper surface of the N-type channel layer are provided with a source electrode cap layer and a drain cap layer, a source electrode is arranged on the upper surface of the source cap layer, a drain electrode is arranged on the upper surface of the drain cap layer, the bottom of the N-type channel layer is provided with a gate electrode at one side adjacent to the source cap layer, a lightly doped region is formed under the gate of partial gate electrode and partial gate drainon the N-type channel layer, and the lightly doped region is an axisymmetric structure of a vertical line of a gate edge of a gate electrode drain side. According to the 4H-SiC metal semiconductor field effect transistor, the electric field concentration effect on the drain side of the gate edge can be alleviated so as to optimize the electric field and current on the drain side of the gate edge,therefore, the breakdown is suppressed, a thermal electron charging effect can be alleviated so as to reduce an interface state, the degradation of the device performance is suppressed, and thereforethe life of the device is improved.

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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