A study of high-dose as and bf2 implantations into simox materials
Norstrom, H × Johansson, T Vanhellemont, J Maex, Karen #
Iop publishing ltd
Semiconductor science and technology vol:8 issue:5 pages:630-633
Thin film, <0.2 mum, SOI layers were implanted with high doses of As and BF2 to simulate actual source/drain formation of MOS devices. Electrical measurements and cross-sectional TEM (XTEM) were used to evaluate the degree of recrystallization achieved after furnace annealing. BF2-implanted samples showed complete recrystallization and a high degree of activation for all examined conditions. XTEM pictures of As-implanted samples showed polycrystalline structures for higher energies; electrical measurements showed increasing sheet resistivity with increasing implantation energy. Arsenic implantation at elevated substrate temperature in order to recrystallize the SOI film during implantation was also studied. XTEM showed no polycrystals or defects, and measured sheet resistivities were comparable to bulk values as indicated by SUPREM3 Simulations. The results of this study are useful when converting an existing NMOS or CMOS process to SIMOX substrates.