Algan/gan MISHEMT high voltage device based on composite drain and its manufacturing method

Abstract

The invention discloses a composite drain-based AlGaN / GaN MIS-HEMT (Metal-Insulator-Semiconductor High-Electron-Mobility Transistor) high-voltage device and a fabrication method thereof. The structure of the device comprises a substrate, a GaN buffer layer, an intrinsic GaN channel layer, an AlN isolating layer and an AlGaN barrier layer sequentially from the bottom up, a source, a grid and a composite drain are arranged on the AlGaN barrier layer, and an insulating medium layer is arranged between the grid and the AlGaN barrier layer; a linear AlGaN layer, a P-type GaN epitaxial layer and a base are sequentially epitaxially arranged on the top of the AlGaN barrier layer between the grid and the composite drain. The invention has the advantages that: when the device is switched on, the 2DEG (2-dimensional electron gas) concentration of a first region and a second region between the grid and the drain increases, and the resistance decreases; when the device is switched off, the 2DEG of the first region is reduced, the 2DEG of the second region is the same as when the device is switched on, the width of the depletion region of the device is increased, the distribution of an electric field is changed, and the breakdown voltage of the device is increased; the composite grid structure prevents the electric field peak from appearing at the edge of the drain, thus increasing the breakdown voltage of the device; an insulated grid structure prevents grid leakage current, and thereby the performance of the device is enhanced.

Description

technical field [0001] The invention relates to a high-voltage device and a manufacturing method thereof, in particular to a compound drain-based AlGaN / GaN high-voltage, low-on-resistance high-voltage device and a manufacturing method thereof, which can be used to manufacture high-voltage and low-on-resistance AlGaN / GaNMISHEMTs A high electron mobility transistor belongs to the technical field of microelectronics. Background technique [0002] In recent years, the third-generation wide bandgap semiconductors represented by SiC and GaN have the characteristics of large bandgap, high breakdown electric field, high thermal conductivity, high saturated electron velocity and high concentration of two-dimensional electron gas at the heterojunction interface. Widespread concern. In theory, high electron mobility transistor HEMT, light emitting diode LED, laser diode LD and other devices made of these materials have obvious superior characteristics than existing devices, so in rece...

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Problems solved by technology

[0007] However, the high-voltage devices with the above two structures all have the disadvantage of large on-resistance

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