The hold temperature of an anneal plays a crucial role in controlling the final activation and diffusion of dopants. A study on the influence of a variety of low temperature pre-anneals on the behavior of dopants and defects for low energy Ge pre-amorphization was conducted. Si wafers were pre-amorphized with 1015 cm–2 Ge+ at energies of 10, 12, 15, 20 and 30keV and implanted with 1015/cm2, 1keV B+. Furnace pre-anneals were performed at 450, 550, 650 and 750C; the samples were subsequently subjected to a spike rapid thermal annealing at 950C. Defect analyses indicated an energy threshold above which the pre-anneal had an effect on the defect density. Further experiments were conducted on the 10keV Ge+ pre-amorphizing implant in which the second anneal step was conducted at 750C for various times. An analysis of the defect evolution with time revealed that the evolution does not follow previously reported Ostwald ripening-type behavior. The microstructure was populated with very small dot-like defects, which simply dissolve with time, suggesting that the B may play some role in the defect evolution.

Influence of Low Temperature Pre-Anneals on Dopant and Defect Behavior for Low Energy Ge Pre-Amorphized Silicon. R.A.Camillo-Castillo, M.E.Law, K.S.Jones, L.M.Rubin: Journal of Vacuum Science & Technology B, 2004, 22[1], 312-6