Studying the environments of ion-implanted arsenic defects in amorphous and recrystallised silicon with impurity EXAFS

With recent developments in solid stare detectors combined with X-rays at glancing angles of incidence, Extended X-ray Absorption Fine Structure (EXAFS) experiments on arsenic ion-implanted into amorphous silicon surfaces have been obtained at dilutions down to 0.01 at%. Structural relaxation processes in both hydrogen-containing and hydrogen-free material have been examined, including the effects of single doping and of counterdoping. In addition the different careers of solid phase epitaxy and amorphisation have been followed from the standpoint of the arsenic environment. EXAFS has been used to establish the degree of crystallinity in the vicinity of arsenic impurities at each stage so that this can be compared with the overall extent of crystalline order in the ion-implanted silicon.