Shallow Sb-doped Si surface layers formed by recoil implantation

Recoil implantation was used to form shallow n+ layers on p-Si by implanting 150 keV Ar+ ions through evaporated Sb layers. By varying the Sb layer thickness, different dopant profiles were achieved. Based on the sheet resistance measurements, it was found that the dopant profiles deviated from theory when the Sb layer thickness was small. Damage effects related to energy deposition by the primary ions were used to explain the differences. It was suggested that these effects could significantly affect the dopant activity and the redistribution of the atoms during heat treatment. These effects were less important for those samples with thick Sb layers. For shallow p-n junction formation, it was essential to keep the damage effects to a low level.