Plasma resistant aluminum oxide coatings for semiconductor processing apparatus by atmospheric aerosol spray method

To decrease the amount of contaminant particles generated during semiconductor manufacturing processes, coatings that can prevent erosion on the inner surfaces and parts of the chamber are required. In this study, plasma resistant dense Al2O3 film was formed on a silicon substrate through the atmospheric aerosol spray method (AAS). AAS is a novel powder spray method, which can form a film under atmospheric pressure and low temperature conditions. It can also form a highly functional film on any type of substrate using metal or non metal powders. The film performance can be evaluated by important film properties such as porosity, crystal structure, hardness, surface roughness, electrical characteristics and erosion properties. Among these, erosion property is especially important for chamber protection in dry etching or plasma oriented equipment. Therefore, we analyzed the thickness, porosity, and structure of a film on a sample section using SEM. Furthermore, we compared the surface morphology and erosion rate of the deposited film before and after erosion according to plasma exposure time through AFM and a surface profiler. With the particles in the size range from 3 to 30 μm, Al2O3 film of 1 to a few hundred micrometers in thickness was formed to have relatively low porosity and dense structure. Moreover, the Al2O3 film was formed by AAS good quality as a plasma resistant coating in terms of surface uniformity and plasma erosion resistivity. These results imply that the films formed by AAS can endure fluorine and oxygen plasma etching environment in semiconductor processes.