A groove preparation method of a GAN base material

Abstract

The invention provides a method for preparing a groove of a GaN-based material. The preparation steps include: coating a photoresist on the surface of a gallium nitride-based material with a specific structure and photoetching a non-groove area; etching the non-groove area and removing Photoresist; the gallium nitride-based material is placed in a corrosive solution for etching; the structure of the gallium nitride-based material includes from bottom to top: epitaxial substrate, GaN buffer layer, sacrificial layer, barrier layer, GaN Cap layer. The gallium nitride-based groove structure prepared by the present invention, because the groove area is based on the full wet etching process, and because of the high selectivity ratio of the corrosion solution to the sacrificial layer, the corrosion depth is uniform and the surface is not damaged, which is conducive to improving device performance , and the method is simple, highly operable and repeatable, and is conducive to large-scale implementation.

Description

technical field [0001] The invention relates to gallium nitride-based (GaN) materials in the technical field of semiconductors, in particular to a method for preparing grooves of GaN-based materials. Background technique [0002] Gallium nitride-based devices have the advantages of strong breakdown field, high electron mobility, and high saturation speed. They are considered to be strong competitors for the next generation of power switching devices, and have been favored by researchers in recent years. However, due to the strong piezoelectric polarization and spontaneous polarization effects of GaN-based heterojunctions, conventional HEMT (High Electron Mobility Transistor) devices based on GaN-based heterojunction structures are usually depletion-mode devices, that is, their threshold voltage is burden. This increases the difficulty and complexity of its gate drive circuit design. At the same time, depletion-type devices also have failure-safe defects, so it is difficult ...

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Problems solved by technology

However, the thinning of the barrier layer of groove technology is usually done by dry etching. On the one hand, dry etching causes uneven etching depth due to the difficulty of precise control of precision, and on the other hand, the etching process causes a large number of surface defects. Seriously affect the electrical characteristics of the device

Another groove technology uses high-temperature oxidation and wet etching to achieve self-stop thinning of the barrier layer. However, due to long-term high-temperature oxidation in this process, the surface characteristics of GaN are likely to deteriorate, which seriously affects the dynamic characteristics of the device.

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