INFLUENCE OF REACTIVE GAS-PRESSURE ON THE DEPOSITION OF AN ALN PROTECTIVE FILM FOR ORGANIC PHOTOCONDUCTOR

The deposition of a protective AlN film for hardening and smoothing of organic photoconductor (OPC) surface is an effective method to prolon g the operating lifetime of the OPC. In this work, the electrophotogra phic properties, surface microhardness and surface roughness of AlN co ated OPC as a function of N-2 gas pressure during the sputtering of Al N film were systematically studied and optimized. When the N-2 partial pressure increases, the surface roughness increases and the surface h ardness decreases. When the N-2 pressure is around 2.7 x 10(-1) Pa (2 mTorr), the electrophotographic properties reach optimized conditions. When the pressure is increased to 5.3 X 10(-1) Pa (4 mTorr), the surf ace roughness increases quickly, the surface hardness decreases, and t he electrophotographic properties can deteriorate quickly as a result of the target poisoning phenomenon during the sputtering process. From this work, it is clearly shown that the deposition of AlN protective film can effectively increase the surface hardness of an OPC without c ausing a deterioration on the electrophotographic properties of the OP C, thereby prolonging the operating lifetime of the OPC. In fact, AIN coated OPC is expected to have a better electrophotographic performanc e in terms of image development. (C) 1998 Elsevier Science S.A.