A kind of lateral conduction gan normally off type misfet device and its manufacturing method

Abstract

The invention relates to a lateral conduction GaN normally-off MISFET device, which comprises a substrate, an epitaxial layer grown on the substrate, a gate, a source electrode, a drain electrode and an insulating layer. The epitaxial layer includes a stress buffer layer and a GaN epitaxial layer grown by primary epitaxial growth, and a secondary epitaxial layer grown on it in a selective region, and the secondary epitaxial layer is an impurity filter layer, a non-doped epitaxial GaN layer from bottom to top and the heterostructure barrier layer, the second epitaxial growth forms the groove channel, the surface of the groove channel and the heterostructure barrier layer covers the insulating layer, the gate covers the groove channel on the insulating layer, and the engraved Both ends of the insulating layer are etched to form source and drain regions, and metal is evaporated on the source and drain regions to form the source and drain in ohmic contact with the heterostructure barrier layer. The device of the present invention has simple structure, high process repeatability and reliability, and can effectively inhibit the diffusion of impurities at the secondary growth interface to the secondary epitaxial layer, thereby effectively reducing the scattering of impurities in 2DEG in the secondary growth heterostructure channel and improving its migration. The rate reduces the on-resistance of the device, so that the device can obtain high output current density and high switching ratio.

Description

technical field [0001] The present invention relates to the technical field of semiconductor devices, in particular to a GaN normally-off MISFET device with lateral conduction and a manufacturing method thereof. Background technique [0002] GaN semiconductor materials have superior properties such as large band gap, high breakdown electric field, large saturated electron drift velocity and high thermal conductivity, and there is a two-dimensional electron gas with high concentration and high electron mobility at the AlGaN / GaN heterojunction interface ( 2DEG), compared with Si materials, it is more suitable for the preparation of power electronic devices with high power, large capacity and high switching speed, and becomes an ideal substitute for the next generation of power switching devices. [0003] In power electronic devices based on converter technology, the power switching transistors that control the converter process are normally off (also known as enhanced), which ...

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Problems solved by technology

However, the following problems will be encountered in this mask process: the SiO is removed by etching 2 SiO 2 The corrosion is clean, and there will be a large amount of residue at the secondary growth interface. During the secondary epitaxial growth, the residual impurity elements are easily diffused into the secondary growth heterostructure channel at high temperature, and the channel 2DEG is seriously scattered, causing Substantial reduction in 2DEG mobility

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