Surface temperature of pulsed-laser-irradiated Si(111)-7 × 7 measured by second-harmonic generation

Abstract

Pulsed laser heating effect on the Si(111)-7 × 7 structure was investigated through surface second-harmonic generation (SHG) of a delayed probe Q-switched YAG laser pulse during a transient temperature jump induced by a pump laser pulse. The time evolution of the surface temperature of the Si(111)-7 × 7 structure induced by a pulsed laser was determined empirically using the time evolution of the SH intensity under a condition for which no structural changes were induced by the laser pulse. The SH intensity from the 7 × 7 structure laser-heated above ∼ 860°C, the transition temperature of the 7 × 7 → “1 × 1”, was also decreased. The results are consistent with a simple extrapolation of the SHG signal from the equilibrium 7 × 7 phase to temperatures above the equilibrium transition over the laser heated period of 0.1 ms.