Epitaxial wafer for diode and preparation method thereof

Abstract

The invention discloses an epitaxial wafer for a diode and a fabrication method of the epitaxial wafer. The epitaxial wafer for the diode comprises a substrate and a GaN two-dimensional growth layer, an SiNx template layer, a GaN recovery layer, a heavily-doped nGaN layer and a light-doped nGaN layer which sequentially cover the substrate along a thickness direction of the substrate, the epitaxial wafer also comprises an AlGaN cap layer, wherein the AlGaN cap layer covers the other side surface, departing from one side of the heavily-doped nGaN layer, of the light-doped nGaN layer, the substrate is a sapphire plain film substrate with an AlN cover layer, the SiNx template layer is formed by in-situ growth of SiH4 and NH3 on the other side surface, departing from one side of the substrate, of the GaN two-dimensional growth layer, and the thickness of the SiNx layer is lower than the thickness of an atomic layer. A diode electronic device fabricated from the epitaxial wafer disclosed by the invention is relatively low in electric leakage and long in service lifetime, the barrier height of a surface layer is increased, the reverse breakdown voltage is remarkably increased, and meanwhile, the positive conduction voltage cannot be risen.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to an epitaxial wafer for a diode and a preparation method thereof. Background technique [0002] Schottky diodes are made using the metal-semiconductor contact principle formed by the contact between metal and semiconductor. It is a hot carrier diode with low forward voltage and ultra-high speed. It is widely used in high frequency and high current , Low-voltage rectifier circuits, microwave electronic mixing circuits, detection circuits, high-frequency digital logic circuits, and AC-DC conversion systems are common discrete devices in electronic devices. In the prior art, Schottky diodes generally use epitaxial wafers as their semiconductor components. There are mainly three kinds of substrates used for epitaxial wafers of GaN Schottky diodes, namely sapphire substrates, silicon substrates and silicon carbide substrates. Among them, since silicon carbide is e...

AI Technical Summary

Problems solved by technology

Due to the high dislocation density of the flat sapphire substrate commonly used in the prior art, the diode electronic devices made of it have high leakage current, easy breakdown, and low crystal quality

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