Intelligent design of GaSb doped single crystals

Doping of GaSb crystals with various elements was found unsatisfactory in order to achieve the desired semiconductor properties until another design concept was introduced providing more intelligent processing. It was shown that an ionized atmosphere can serve as a passivator in a wider range of tellurium concentration and that the equilibrium between passivated and active donors is created according to the ratio of p- to n-type dopants in the starting melt of GaSb crystals highly doped with tellurium. The Czochralski method without encapsulant in the flowing atmosphere of ionized hydrogen was employed and the resulting intrinsic free carrier concentration was several times lower than that obtained by using simple (molecular) hydrogen.