Influence of scribe damage on pits formed by immersion of Si in HF solution

This paper describes the influence of deliberately applied scribe damage on pits formed in (001) Si wafers by immersion in a hydrofluoric acid solution. Immersion caused dense pitting, which correlates with stacking faults. However, a pit-poor region appears in the strained vicinity of the scribe damage. The strain introduced in the damage vicinity is thought to promote Si dissolution judging from the measurement of induced current and voltage for a wafer subjected to bending stress. For a wafer annealed subsequently to damage application, a pit-rich region is found to be propagated along the (111) and (001) intersection in the damage vicinity where gettering is presumed to have occurred. Both the pit-poor and pit-rich regions present for the respective wafers are ascertained to be wider by one order of magnitude than the dislocation formation region introduced in the damage area. The pit formation is strongly influenced by the elastic strain, which is formed around the damage, as well as by mechanical damage gettering.