Properties of ion-implanted strained-Si/SiGe heterostructures

In this paper the properties of ion-implanted strained-silicon/SiGe heterostructures are investigated. The strained-silicon layers were completely re-crystallized by rapid-thermal annealing at 900°C or higher. Arsenic diffusivity was identical in strained and unstrained silicon but was higher than both of these in SiGe. Boron diffusivity in SiGe was lower than that in silicon. Electron mobility was greater by about 20-30% in strained silicon than in silicon and lower by about 20-30% in Si_0.7Ge_0.3 than in silicon. Hole mobility was greater by about 30-40% in strained silicon than in silicon and lower by about 5-8% in Si_0.7Ge_0.3 than in silicon. Parasitic resistance in the source/drain region can be decreased if the region consists mostly of strained silicon.