Critical undercoolings for the transition from the lateral to continuous growth in undercooled silicon and germanium

Abstract The effects of crystal–liquid interface energy and undercooling on a crystal–liquid interface structure and the growth mode of undercooled semiconductors have been investigated. A factor to predict the structure of the solid–liquid interface has been identified. Criterions expressed as the critical nucleation undercoolings (Δ T * 1 and Δ T * 2 ) and kinetic undercoolings (Δ T K1 * and Δ T K2 * ) to judge the transition of growth mode in undercooled semiconductor have been developed. The growth mode of a semiconductor is a lateral one when nucleation undercooling is lower than Δ T * 1 or kinetic undercooling is lower than Δ T K1 * , a continuous one when nucleation undercooling is higher than Δ T * 2 or kinetic undercooling is higher than Δ T K2 * , and an intermediary one in the nucleation undercooling region from Δ T * 1 to Δ T * 2 or kinetic undercooling region from Δ T K1 * to Δ T K2 * . The critical undercoolings for the growth transition predicted from the present criterions for silicon and germanium are in very good agreement with the experimentally measured results.