Chemical and nanomechanical characteristics of fluorocarbon thin films deposited by using plasma enhanced chemical vapor deposition

Abstract

In this study, the chemical and nanomechanical characteristics of fluorocarbon (FC) films deposited by using plasma-enhanced chemical vapor deposition on Al were evaluated to apply them as antistiction layers. The calculated deposition rate with C4F8 was 325 nm/min at an optimized process condition of 10 seem, 30 W, and 340 mTorr. The contact angles of the FC thin films on Al were around 110 degrees, regardless of the deposition time. The surface energies were around 14 mN/m, and the contact angle hysteresis was lower than 35 degrees. FTIR-ATR (Fourier transform infrared attenuated total reflection) spectra showed the presence of fluorocarbon groups. The adhesion and friction force after FC film deposition showed lower and more stable values than those of bare Al. Depositing the FC films at powers above 50 W increased the hysteresis, the adhesion force, the roughness and the friction force. The addition of Ar resulted in a decrease in the thickness of the FC film during deposition. The deposited FC films gradually decomposed at 200 degrees C.