Measurement and Analysis of Composition and Depth Profile of H in Amorphous Si1-xCx:H Films

Composition in amorphous Si_1-xC_x:H heteroepitaxial thin films on Si (100) by plasma enhanced chemical vapour deposition (PECVD) is analysed. The unknown x (0.45--0.57) and the depth profile of hydrogen in the thin films are characterized by Rutherford backscattering spectrum (RBS), resonance-nuclear reaction analysis (R-NRA) and elastic recoil detection (ERD), respectively. In addition, the depth profile of hydrogen in the unannealed thin films is compared to that of the annealed thin films with rapid thermal annealing (RTA) or laser spike annealing (LSA) in nitrogen atmosphere. The results indicate that the stoichiometric amorphous SiC can be produced by PECVD when the ratio of CH₄/SiH₄ is approximately equal to 25. The content of hydrogen decreases suddenly from 35% to 1% after 1150°C annealing. RTA can reduce hydrogen in SiC films effectively than LSA.