Precipitation Behaviors of Rapid Thermal Annealing Treated Silicon Wafers under Various Thermal Cycles

Abstract

A “2-step Rapid Thermal Annealing (RTA)” treatment in NH3 and Ar gas is capable of producing a high density (6-8x109/cm3) of precipitates in a remarkably uniform profile in the 300mm silicon wafers, independently of thermal cycle, oxygen content and pre-thermal history. The profile sharply transitions from a shallow denuded zone to the fixed and uniform density in the bulk. Such a feature would guarantee a sufficient amount of gettering sinks to be retained in the extremely thinned wafers. The shape of the depth profile evolves in proportion to the thermal budget, following well the model of VO2 nucleation and growth reported previously.