High electron mobility transistor epitaxial wafer preparation method for improving crystal quality

Abstract

The invention provides a high-electron-mobility transistor epitaxial wafer preparation method capable of improving crystal quality, and belongs to the technical field of semiconductor devices. And carrying out plasma treatment on the surface of the AlN layer by using N2O gas. And carrying out plasma treatment on the surface of the AlN layer by using the nitrogen atom group and the oxygen atom group with positive charges. The nitrogen atom groups with positive charges can fill nitrogen vacancy defects in the AlN layer of the negative electrode, and the defects are reduced. Oxygen atoms with negative charges are decomposed from oxide on the surface of the silicon substrate and are combined with oxygen atoms in the N2O plasma to generate oxygen molecules, and impurities are reduced. The hydrogen carries out plasma treatment on the surface of the AlN layer, and hydrogen atoms and oxygen atoms can be combined to generate H2O which is discharged out of the reaction cavity. Defects and impurities existing in the AlN layer are effectively reduced, and the quality of the AlN layer is effectively improved, so that the quality of the finally obtained high-electron-mobility transistor is improved.

Description

technical field [0001] The disclosure relates to the technical field of semiconductor devices, in particular to a method for preparing high electron mobility transistor epitaxial wafers with improved crystal quality. Background technique [0002] HEMT (High Electron Mobility Transistor, High Electron Mobility Transistor) is a heterojunction field effect transistor, which is widely used in various electrical appliances. The HEMT epitaxial wafer is the basis for preparing HEMT devices. The HEMT epitaxial wafer includes a substrate and an AlN layer, an AlGaN buffer layer, a GaN high resistance layer, a GaN channel layer, an AlGaN barrier layer and a GaN capping layer stacked on the substrate in sequence. [0003] HEMT epitaxial wafers often use silicon substrates as substrates for growth, but on the one hand, oxides similar to silicon oxide are prone to exist on the surface of silicon substrates. These oxides are decomposed during high-temperature epitaxial growth, and the deco...

AI Technical Summary

Problems solved by technology

[0003] HEMT epitaxial wafers often use silicon substrates as substrates for growth, but on the one hand, oxides similar to silicon oxide are prone to exist on the surface of silicon substrates. These oxides are decomposed during high-temperature epitaxial growth, and the decomposed oxygen atoms will Into the epitaxial material grown on the silicon substrate, as impurities affect the quality of the final high electron mobility transistor epitaxial wafer; on the other hand, when the AlN layer is grown on the silicon substrate, the Al as the growth source of the AlN layer The pre-reaction between the organic source and ammonia is very serious, and the Ⅴ / Ⅲ ratio of AlN layer growth is low, which will lead to more N vacancy defect states in the AlN layer, resulting in more defects in the obtained high electron mobility transistor ; More impurities and defects will affect the quality of the final high electron mobility transistor

Images