Implementation of plasma enhanced CVD system and characterization of plasma silicon nitride film

Abstract

The system of the plasma enhanced chemical vapor deposition was implemented which has the merit of the low temperature of substrate (not greater than $400\,^\circ\!C$) as compared with the conventional high temperature CVD process. The reactor of the system is parallel-type in which gases flow radially. It is the high vacuum-tight system which can be evacuated to $5\times10^{-6}$ torr with mechanical and diffusion pump. And SiN films were deposited on substrate material in the system. The SiN film deposition was made by the process of the reaction of $SiH_4$ and $NH_3$ gas varying process parameters such as rf power, substrate temperature, reactant gas mixing raito and reactor pressure. The thicknesses and refractive indexes of films were measured with Ellipsometer for system characterization and looking for good electrical properties which include dielectric field strength, resistivity and C-V characteristics. For C-V measurement, MIS(or MNS) structure was made with Al evaporation of 5000 $\mbox{\AA}$ on SiN-Si substrate without a back metal plate. The substrate materials were (100) oriented p-type silicon wafers.