Accession Number : AD0622961

Title :   NGE-PGAAS HETEROJUNCTIONS.

Descriptive Note : Interim technical rept.,

Corporate Author : CARNEGIE INST OF TECH PITTSBURGH PA DEPT OF ELECTRICAL ENGINEERING

Personal Author(s) : Riben,Arthur R.

Report Date : FEB 1965

Pagination or Media Count : 166

Abstract : This thesis presents a model which includes the effect of carrier tunneling throught the forbidden energy region of the semiconductors, and shows that the experimental characteristics of nGe-pGaAs heterojunctions are explained by recombination-tunneling mechanisms, which are different for the forward and reverse directions. The predominance of the tunneling current over the thermal current in nGe-pGaAs devices is shown to be the result of a large energy discontinuity between the valence bands of the two materials. The methods of fabricating these heterojunctions are discussed, and it is shown that the electrical characteristics are related to the original substrate preparation. The work indicates that growths on cleaved substrates will have the smallest number of interface defects, and thus the subsequent devices will have the lowest current densities. Injection studies were also carried out on many devices, and the results were consistent with the existence of a majority carrier tunneling mechanism as the predominant cause of charge transport. A conclusion drawn from this work is that in order to further study the possibility of obtaining increased emitter injection efficiency be means of a wide band-gap emitter transistor, the base material should be of the conductivity type such that the minority carriers are in the energy band which has the smaller discontinuity. (Author)

Descriptors :   (*COMPOSITE MATERIALS, SEMICONDUCTORS), (*SEMICONDUCTORS, TUNNELING(ELECTRONICS)), (*TUNNELING(ELECTRONICS), SEMICONDUCTOR DEVICES), GERMANIUM, GALLIUM ALLOYS, ARSENIC ALLOYS, SEMICONDUCTOR DEVICES, EPITAXIAL GROWTH, ELECTRICAL PROPERTIES

Distribution Statement : APPROVED FOR PUBLIC RELEASE