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Abstract

Particulate contamination can occur in physical vapor deposition (PVD) systems when sputtered target material accumulates on the walls of the processing chamber and flakes off onto the workpiece. In a method for preparing a shield to reduce particulate contamination, sheet metal is formed to conform to the surfaces of the deposition chamber. The base metal is roughened, such as by sand blasting. A layer of coating material, whose coefficient of thermal expansion (CTE) is similar to that of the target material, is applied to the roughened base metal surface by a thermal spraying process. The surface of the coating is very rough, more than five times rougher than the underlying base metal texture. When the coating CTE and surface roughness are chosen carefully, shield performance can be optimized, resulting in longer processing times between shield replacements, reduced PVD chamber maintenance and less down time in these systems.

First Claim