Method for preparing gate dielectric on silicon carbide material

Abstract

The invention discloses a method for preparing gate dielectric on silicon carbide material, comprising: growing silicon oxide of 1 nanometer on silicon carbide surface under nitrous oxide environment through annealing mode; preparing aluminium oxide dielectric film of 1 nanometer through atom layer depositing method, wherein the precursor adopts trimethylaluminium and water, again preparing aluminium oxide dielectric film of 1 nanometer through the atom layer depositing method, wherein the precursor adopts trimethylaluminium and ozone, treating the surface by nitrogen plasma; circulating five times according to the step (2); and finally degrading under the nitrous oxide environment.

Description

technical field [0001] The invention relates to the manufacture of semiconductor devices, especially the preparation technology of silicon carbide upper gate dielectric. Background technique [0002] In recent years, silicon carbide MOSFET device technology has continued to develop, using silicon oxide as the gate dielectric to passivate the surface of silicon carbide to make MOS devices, and using nitrogen oxide and N 2 Annealing in the O environment has shown very high MOS interface characteristics of silicon carbide, but the electron mobility on the surface of silicon carbide is still very low; with the continuous advancement of atomic layer deposition technology, aluminum oxide dielectric deposition is becoming more and more mature and stable. Depositing aluminum oxide as a gate dielectric by atomic layer deposition technology has become an important technical trend to solve the high density of defect states at the silicon carbide MOS interface. Contents of the inventi...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is that the existing silicon carbide MOS interface state density is large, resulting in low effective mobility of silicon carbide MOSFET devices and greatly limiting device performance; the present invention uses SiO 2 interface layer technology, using the N 2 Annealing technology in O environment forms SiO with low interface defect state density on the surface of silicon carbide 2 ; and using atomic layer deposition technology on SiO 2 Aluminum oxide dielectric is deposited on the interface layer, so as to realize the preparation of gate dielectric with low density of dielectric defect states on the surface of silicon carbide

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