Abstract
Bead blasting and thermal spray coatings are often applied on process kits used in vacuum deposition chambers to improve adhesion between kit surfaces and deposited films. This study shows that in order to maximize chamber service time and reduce processing defects, thermal expansion mismatches must be considered between chamber components, sprayed coatings, and vacuum deposited films. When a titanium sheet coated with arc sprayed aluminum was placed in a titanium nitride deposition chamber, significant particle spiking was observed. However, during the same period of chamber service time, particle performance was stable for titanium coated with arc sprayed molybdenum. It should be noted that the thermal expansion coefficients of Ti and Mo are much closer than those of Ti and Al. By further optimizing the cohesion strength of the arc-sprayed Mo coating, even lower particle counts have been achieved, corresponding to fewer processing defects and prolonged chamber kit lifetime.
