Electronic dilation of si during pulsed laser annealing

Abstract

The equilibrium lattice constant of a solid depends upon the occupation of its electronic energy levels. When large numbers of electrons are exicited across the band gap of a semiconductor, as during pulsed laser annealing, the material will adjust towards the new equilibrium. Here the sign and magnitude of this adjustment to be expected for Si subjected to pulsed laser annealing conditions is discussed in terms of Pauling’s bond-order-bond-length relationship. It is estimated that at the laser annealing threshold, if the true lattice temperature is 300°C, the total dilation is that which would occur at 960°C if there were no electronic contribution. A qualitative explanation is suggested for the anomalous strain relief of Si on sapphire by pulsed laser annealing ovserved by Yamada et al. © 1982 The Japan Society of Applied Physics.