Non-Contact, Non-Destructive Characterization of Crystal Quality in Ultra-Shallow ion Implanted Silicon Wafers Before and after Annealing

Abstract

Ultraviolet (UV) Raman scattering spectroscopy provides new insight into the recrystallization process versus depth in the ultra-shallow ion-implanted layer not provided by conventional characterization techniques. The recrystallization process in ultra-shallow B-implanted layers on silicon was characterized by Raman scattering spectroscopy under UV excitation. To recrystallize damaged layers after ion implantation, rapid annealing processes were carried out in both a millisecond flash annealing system and a spike annealing system. The effectiveness of this anneal is compared to Raman evaluation of non-USJ, B-implanted layers with hundred nanometer scale depth thoroughly annealed in a near isothermal hot wall chamber. By making use of the shallow penetration depth of UV light in silicon, we can distinguish Raman signals of single-crystalline, deficiently recrystallized, as well as amorphous silicon. Although, a clear, single crystalline lattice image was observed by transmission electron microscopy (TEM), the UV-Raman spectroscopy also sensitively detected deterioration of the lattice, but in nondestructive testing