AlGaN/GaN heterojunction device with in-situ gate medium and manufacturing method thereof

Abstract

The invention discloses an AlGaN / GaN heterojunction device with an in-situ gate medium and a manufacturing method thereof. The device comprises an AlGaN / GaN heterojunction structure, a source electrode, a drain electrode and a gate electrode that are formed on a substrate. A BN film or a BAIN film, serving as a gate medium, is formed on the heterojunction structure through in-situ epitaxial growth. The manufacturing method comprises the steps: forming an AlGaN / GaN heterojunction structure on a substrate, placing the heterojunction structure in an epitaxial growth apparatus, inputting a nitrogen source and a boron source and an aluminium source that serves as a selectable raw material, and then forming a BN film or a BAIN film, serving as a gate medium, on the heterojunction structure through in-situ epitaxial growth. A high-quality BN or BAIN gate medium can be formed during epitaxy of device materials without damage to the structure of the device, and the gate medium has a high dielectric constant and a wide forbidden band width. Therefore, through adoption of the gate medium, the performance of a semiconductor electronic device with a GaN / AlGaN heterojunction structure is improved, gate leakage currents are minimized, a current avalanche effect and a hysteresis phenomenon are inhibited, and the overall performance of the device is improved.

Description

technical field [0001] The invention relates to a Group III nitride semiconductor device, especially an AlGaN / GaN heterojunction device with an in-situ gate dielectric and a manufacturing method thereof, belonging to the field of semiconductor power devices. technical background [0002] Since the 1960s and 1970s, III-V compound semiconductor electronic devices have become the focus of people's research, especially since it was discovered in the 1990s that Mg doping was used to realize the epitaxy of P-type GaN materials. The research on bandgap semiconductor materials and devices has entered a new research stage, and GaN-related materials and devices are still international research hotspots. The GaN bulk material has a band gap of 3.4eV, a breakdown field strength of 3.3MV / cm, and a two-dimensional electron gas mobility formed with AlGaN greater than 2000cm 2 / V·s, the carrier surface concentration can reach 1.0E10 13 cm -2 Therefore, semiconductor devices with AlGaN / Ga...

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Problems solved by technology

[0006] Whether using SiO 2 or SiN x still Al 2 o 3 Both can be used as the gate dielectric passivation layer of AlGaN / GaN heterojunction devices, and exhibit some superior properties, but each method has its own shortcomings and deficiencies. For example, growing these dielectric layers generally requires AlGaN / GaN heterojunction The junction material is taken out from the reaction chamber of the epitaxial equipment, and then grown by PECVD or ALD equipment, which leads to the oxidation and contamination of the material interface, and the increase of the interface state, so that the leakage current on the gate of the device after passivation increases

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