Effect of O-2 Pretreatment on Fluorinated Carbon Film Surfaces

Abstract

Fluorocarbon (FC) film is used in micro-electro-mechanical system (MEMS) processes as an anti-stiction layer. We studied the effect of O-2 pretreatment on FC film using an X-ray photoelectron spectroscope (XPS) and atomic force microscope (AFM) to measure the surface roughness and to characterize the composition of the film. CF and CF3 were observed for all temperatures at 6.67 Pa. A high oxygen concentration was found in the film deposited at 250 degrees C. An AFM analysis of the surface roughness showed agglomeration on the film surface, while none was found on the films deposited at 25 degrees C and 100 degrees C. Therefore, the O-2 pretreatment seemed to facilitate oxidation at a deposition temperature of 250 degrees C. Since our results showed that a smooth anti-stiction layer could be deposited at 100 degrees C without any oxidation occurring, the optimum conditions for FC deposition were 100 degrees C at a pressure of 6.67 Pa. Therefore, this study showed an important relationship between O-2 pretreatment and deposition temperature. [doi: 10.2320/matertrans.MRA2008295]