Carrier Lifetime Reduction by Argon Implantation into Silicon

The reduction of carrier generation lifetime caused by argon implantation into silicon has been studied as a function of argon dose and annealing treatments. The capacitance transient technique was used to deduce that: ( i ) carrier generation lifetime in the depletion region decreases by four orders of magnitude with doses up to 10 14 cm −2 , and varies inversely with dose; ( ii ) the separable contribution to capacitance relaxation due to surface generation and diffusion varies as the square of the dose. The region of low lifetime appears to remain localized within 1 μm from the surface even after annealing for 1h at 1200°C. Partial recovery of generation lifetime occurs after annealing for 1h at 1100° or 1200°C. Complete recovery was observed only after several hours at 1200°C, and slow cooling (2°C min −1 ). The resistance to high temperature treatment implies that regions of low lifetime can be incorporated with three‐dimensional control into device structures.