Transparent BCN coatings by RF PACVD at low temperature using metallo-organic precursors

The deposition of transparent BCN was carried out on polycarbonate substrates by means of different radio frequency plasma assisted CVD systems (inductively coupled RF PACVD and capacitively coupled RF PACVD). We have used different metallo-organics as precursors which are N-trimethylborazine (TMB) and N-pyrrolidino diethylamine (PMB). By varying the deposition parameters (plasma power, reactor pressure and substrate temperature) coatings were prepared with hardness values ranging from 677 to 1400 Hk0.005. The surface roughness of the deposited layers was measured by profilometry. It was found that the deposited layers were transparent, smooth, dense and stable in room ambient. The deposited films have a high transmission in the UV-visible region measured by UV/vis-spectroscopy and have a low refractive index (1.22-1.52) investigated by ellipsometry.