The Influence of the Amorphous Phase on Ion Distributions and Annealing Behavior of Group III and Group V Ions Implanted into Silicon

A study has been made of room‐temperature implantations of group III and group V ions into amorphous Si layers prepared by the previous implantation of Si ions into crystalline Si substrates. Neutron activation combined with anodic oxidation and HF stripping techniques was used to determine the proflies of the implanted ions for Ga⁷¹ and Sb¹²¹. Electrical evaluation of the implanted layers by Hall effect and sheet resistivity measurements in conjunction with layer removal techniques yielded profiles of the net electrically active species and the depth variation of mobility after annealing for 30 min in the temperature range 600°–900°C. The ion species studied were B¹¹ (60–200 keV), Al²⁷ (200 keV), Ga^69&71 (140 and 280 keV), P³¹ (100–280 keV), As⁷⁵ (280 keV), Sb^121&123 (120 and 260 keV), and Bi²⁰⁹ (240 keV). The epitaxial regrowth of the amorphous phase at 600°C causes most of the implanted ions within this region to become electrically active and uncompensated for the ion species B, P, As, Sb, and Bi even for peak ion concentrations in excess of 10²⁰ cm⁻³. For Al and Ga implants, the number of carriers was less than the number of implanted ions. The profiles obtained for these implantations into amorphous Si were compared with predictions based on the theory of Lindhard, Scharff, and Schiott.