AlGaN/GaN heterojunction enhancement-mode device with in-situ SiN cap layer and production method thereof

Abstract

The invention discloses an AlGaN / GaN heterojunction enhancement-mode device with an in-situ SiN cap layer and a production method thereof and aims to solve the problems of poor threshold voltage uniformity and process repeatability of enhancement-mode high electron mobility transistors (HEMT) in the prior art. The production process includes : (1) growing an intrinsic GaN layer on a SiC or sapphire substrate, and then growing an AlGaN barrier layer with a growing thickness of 8-16nm and 25-35% of the Al component; (2) growing the in-situ SiN cap layer on the surface of the AlGaN barrier layer, and performing grating groove etching to expose a grating area; (3) depositing metal Ni and Al on the surface of the AlGaN barrier layer exposed out of the grating area; (4) performing high-temperature heat treatment of an oxygen environment through a fast heat annealing furnace at 800-860DEG C to form NiO and Al2O3 layers; and (5) performing active area mesa isolation on the in-situ SiN cap layer to finish source and drain ohmic contact electrodes, and producing gate electrodes on the Al2O3 layer. The device and the method have the advantages of being high in threshold voltage, small in gate leakage current, high in process repeatability and controllability and capable of being used on high-operating-voltage enhancement-mode AlGaN / GaN heterojunction high-tension switchs and basic units of GaN-based combinational logic circuits.

Description

technical field [0001] The invention belongs to the technical field of microelectronics and relates to the manufacture of semiconductor devices, in particular to an in-situ SN cap layer AlGaN / GaN heterojunction enhanced device and a manufacturing method, which can be used to manufacture enhanced high electron mobility transistors. Background technique [0002] In recent years, the third bandgap semiconductor represented by SiC and GaN has 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. It has received widespread attention. 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 recent years, researchers at home and abroad have conducted extensive and in-depth researc...

AI Technical Summary

Problems solved by technology

However, the use of a thin AlGaN barrier layer reduces the two-dimensional electron gas density between the source and drain, and increases the series resistance of the gate source and gate drain, which affects device characteristics.

Moreover, this solution only uses a thin barrier layer, and does not use trench gate or F implantation for gate area treatment, so the threshold voltage of the manufactured device is lower

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