the process of formation of n-type by ion implantation of arsenic and silicon germanium on a substrate

摘要

A method for forming N conductivity-type regions in a silicon substrate comprising ion implanting arsenic to form a region in said substrate having an arsenic atom concentration of at least 1 x 10-2 As atoms/total atoms in substrate, and ion implanting germanium into said substrate region. Even though the atomic radius of arsenic is very close to that of silicon -- the arsenic radius is only 0.5% smaller -- when high arsenic atom concentrations of at least 1 x 10-2 atoms/total atoms in the substrate are introduced in the substrate, and such high concentrations are only possible when arsenic is ion implanted, then atomic misfit dislocations will occur. The implanted germanium atoms compensate for the lattice strain in the silicon to minimize dislocations.