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

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 (ΔT*1 and ΔT*2) and kinetic undercoolings (ΔTK1* and ΔTK2*) 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 ΔT*1 or kinetic undercooling is lower than ΔTK1*, a continuous one when nucleation undercooling is higher than ΔT*2 or kinetic undercooling is higher than ΔTK2*, and an intermediary one in the nucleation undercooling region from ΔT*1 to ΔT*2 or kinetic undercooling region from ΔTK1* to ΔTK2*. 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.