Method for forming shallow junctions in semiconductor wafers using controlled, low level oxygen ambients during annealing

摘要

A method is provided for forming a shallow junction in a semiconductor wafer that has been implanted with a dopant material. The dopant material is activated by thermal processing of the semiconductor wafer in a thermal processing chamber at a selected temperature for a selected time. The oxygen concentration in the thermal processing chamber during activation of the dopant material is controlled at or near a selected level less than a background level that is typically present when the thermal processing chamber is filled with a process gas. The oxygen concentration may be controlled at or near a selected level in a range less than 1000 parts per million and is preferably controlled at or near a selected level in a range of about 30-300 parts per million. The method is particularly useful for implanted boron or BF2 ions, but may be used for any dopant material.