GaN-based high-electron-mobility transistor epitaxial wafer and preparation method thereof

Abstract

The invention provides a GaN-based high-electron-mobility transistor epitaxial wafer and a preparation method thereof, and belongs to the technical field of semiconductors. The GaN-based high-electron-mobility transistor epitaxial wafer comprises a substrate, a buffer layer, a high-resistance buffer layer, a channel layer, an AlGaN barrier layer and a cap layer, wherein the buffer layer, the high-resistance buffer layer, the channel layer, the AlGaN barrier layer and the cap layer are stacked on the substrate, the cap layer comprises first sub-layers and second sub-layers which grow alternately, the first sub-layers are GaN layers, and the second sub-layers are InGaN layers. The first sub-layer and the second sub-layer are both doped with a main doping element, the main doping element is Be or Mg, the second sub-layer is also doped with an auxiliary doping element, and the auxiliary doping element is O, Mg, Si or Zn. According to the GaN-based high-electron-mobility transistor epitaxial wafer, the generation of complexes can be reduced, and the activation energy of the P-type dopant in the cap layer is reduced, so that the P-type cap layer with high doping concentration is obtained.

Description

technical field [0001] The disclosure relates to the technical field of semiconductors, in particular to a gallium nitride-based high electron mobility transistor epitaxial wafer and a preparation method thereof. Background technique [0002] HEMT (High Electron Mobility Transistor, High Electron Mobility Transistor) based on AlGaN (aluminum gallium nitride) / GaN (gallium nitride) heterostructure has high current density, critical breakdown voltage and electron mobility. The field of high temperature electronic devices has very important application value. [0003] A HEMT typically includes a chip and a source, drain, and gate located on the chip. Chips are obtained from epitaxial wafers. The structure of the epitaxial wafer generally includes a substrate and a buffer layer, a high-resistance buffer layer, a channel layer, an AlGaN barrier layer and a cap layer sequentially stacked on the substrate. At present, there are four main technologies in the world to realize galli...

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Problems solved by technology

[0004] At present, the P-type GaN cap layer is mainly doped with Mg, but Mg doped has the problem that it is easily passivated by H, resulting in high activation energy, and the ionization of Mg The rate is very low, and a higher doping concentration is required to achieve P-type, and Mg as an acceptor will also form a complex with N vacancies in GaN MgGa-VN, forming a self-compensation effect, resulting in a decrease in the carrier concentration

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