Double-heterojunction HEMT containing component gradual-changing high resistance buffer layer and manufacturing method thereof

Abstract

The invention discloses a double-heterojunction HEMT containing a component gradual-changing high resistance buffer layer and a manufacturing method thereof. The double-heterojunction HEMT comprises asubstrate, a nucleating layer located on the substrate, the high resistance buffer layer located on thenucleating layer, a high mobility channel layer located on thehigh resistance buffer layer, a barrier layer located on thehigh mobility channel layer and a capping layer located on the barrier layer, wherein the high resistance buffer layer comprises an intentional doping layer and an unintentional doping component gradual-changing layer located on the intentional doping layer, and components of the unintentional doping component gradual-changing layerare gradually reduced in the direction of epitaxial growth of the double-heterojunction HEMT. According to the double-heterojunction HEMT, on the one hand, channel electron mobility is increased, limiting ability to two-dimensional electrongasis improved, electric leakage of the buffer layer of the double-heterojunction HEMT is reduced, breakdown voltage is increased, and regulatory capacity of a gate is improved; on the other hand, component gradual-changing of aluminumof aluminum-gallium-nitrogen in the high resistance buffer layer is used, latticestrain is lowered, piezoelectric polarization is reduced, and working stability andreliability of the double-heterojunction HEMTis integrally improved.

Description

technical field [0001] The disclosure belongs to the technical field of semiconductors, and relates to a double heterojunction HEMT containing a high-resistance buffer layer with graded composition and a manufacturing method. Background technique [0002] As a typical representative of the third-generation wide-bandgap semiconductor, gallium nitride has excellent physical and chemical properties, and is very suitable for the development of high-frequency, high-voltage, high-power devices and circuits. High electron mobility transistors developed using gallium nitride , high current density, high power density, low noise, good frequency characteristics, and has broad application prospects in the field of military and civilian microwave power. [0003] The principle of Gallium Nitride-based High Electron Mobility Transistor (HEMT, High Electron Mobility Transistor) is: due to the different forbidden bands of the two materials that make up the heterojunction, a potential barrie...

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Problems solved by technology

However, when the Al composition is high, the large lattice mismatch will lead to the deterioration of the crystal quality, surface and interface quality of the AlGaN barrier layer, and the strain-induced deep-level defects will increase, which will enhance the scattering and reduce the mobility. Moreover, the stress formed by the lattice mismatch will seriously affect the reliability of the device through the inverse piezoelectric effect.

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