An Ion-Scattering Study of Oxygen Indiffusion During Pulsed Laser Annealing/Cleaning of Silicon

Abstract

Oxygen indiffusion during pulsed laser annealing of silicon has been studied 16 16 using the 8 0(m,m) 8 0 resonance at 3.045 MeV. Anneals were carried out with a Q-switched ruby laser, energy density of the pulses 1.5 J/cm 2 , pulse width 20 ns. No evidence for oxygen indiffusion was found, neither for ion-implanted single pulse air-annealed silicon nor for a silicon wafer, cleaned with 8 laser shots in a UHV environment. In the latter case, the upper limit of the oxygen concentration was found to be 3.1* 1018 at/cm 3 , which is lower than the solid solubility limit of oxygen in silicon. The non-occurrence of indiffusion is consistent with the dissolution time of Si0 2 in Si, which is orders of magnitude longer than the melt duration of the Si-substrate.