EFFECTS OF CARBON IMPLANTATION ON GENERATION LIFETIME IN SILICON

In this study, we present characterization of metal-oxide-silicon (MOS ) capacitors fabricated on carbon (C-12) implanted Si substrates. Carb on was implanted at an energy of 50 keV with doses ranging from 1X10(1 2) Cm-2 to 4.1X10(15) Cm-2. Metal-oxide silicon capacitors were fabric ated and used to determine the MOS capacitance-voltage (C-V) and capac itance-time (C-t) behavior. These measurements revealed a strong corre lation between carrier lifetime and the C dose. Degradation in lifetim e was observed for C dose levels as low as 4X10(12) cm(-2). At C doses equal to and above 6.4X10(13) Cm-2, extremely low generation lifetime s were obtained (similar to 10(-7) s). On the other hand, for C dose l evels higher than 2.7X10(14) cm(-2), a low accumulation capacitance wa s observed at high frequencies and attributed to hole traps. Below thi s dose, both flatband voltage and interface trap density of the C impl anted samples were comparable to those of the monitors. (C) 1996 Ameri can Institute of Physics.