Preparation of anti-reflective and protective diamond-like carbon film on Si substrate by femto-second pulsed laser deposition

A femtosecond pulsed laser(800 nm, 120 fs, 3 W, 1 000 Hz) was used to deposit diamond-like carbon(DLC) films on Si substrate. Effects of bias, substrate temperature and oxygen ambient on DLC films were studied. Experiments show that the best DLC film was deposited under the conditions of room temperature, no bias and low oxygen pressure(2 Pa). The hydrogenfree DLC film was deposited on one side of Si substrate, and on the other side, the common anti-reflective film was pre-deposited. The average transmittance at 3~5 μm waveband was larger than 90%, and the nano-hardness was up to 40 GPa. There were no nicks on the film after being rubbed for 105 times by a 9.8 N rubber. Furthermore, the films have passed the high temperature, low temperature and salt-fog tests in military standards. T