SUPERCRITICAL SUPERSATURATIONS AND ULTRAFAST COOLING OF THE GROWTH SOLUTION IN LIQUID-PHASE EPITAXY OF SEMICONDUCTORS

A method for accomplishing ultrafast cooling is proposed which makes p ossible supercritical supersaturations of the growth solution in liqui d-phase epitaxy. Growth boat designs providing cooling rates as high a s 10(2)-10(3) degrees C s(-1) are considered. The temperatures of cont act, T-c, of a GaAs substrate with a Ga-based solution and of a Si sub strate with a Sn-based growth solution, calculated for various substra te (T-s) and solution temperatures T-l, are in good agreement with exp erimental values, The maximum attainable supercooling is markedly incr eased to as high as 70 degrees C for the Ga-As system, when the growth solution is subjected to ultrafast cooling. The prospects of using th e method for fabricating heterostructures with a large lattice mismatc h are discussed.