Time-Resolved Reflectivity Measurement of the Pressure-Enhanced Crystallization Rate of Amorphous Si in a Diamond Anvil Cell

Abstract

ABSTRACTWe have measured the pressure dependence of the solid phase epitaxial growth (SPEG) rate of self-implanted Si (100) by using the in-situ time-resolved reflectivity technique [1] in a hightemperature and high-pressure diamond anvil cell (DAC). With fluid argon as the pressure transmission medium, a clean and perfectly hydrostatic pressure environment is achieved around the sample. The external heating geometry employed in the DAC provides a uniform temperature across the sample. At temperatures in the range of 530 – 550 °C and pressure up to 50 kbars (5 GPa), the growth rate is enhanced by up to a factor of ten over that at 1 atmosphere pressure. The results are characterized by a negative activation volume of approximately −3.0 cm3/mole (−27% of the atomic volume). These preliminary results show a significantly weaker pressure dependence than does the previous work of Nygren et al. [2], who found an activation volume of −8.7 cm3/mole. The implications of these results for the nature of the defect responsible for thermal SPEG and irradiation enhanced SPEG is discussed.