Investigation of residual impurity content in GaAs layers grown by VPE under very low pressure conditions.

Autor: Camassel, J., Laurenti, J., Juillaguet, S., Wolter, K., Deschler, M., Ambross, S., Grüter, K.
Zdroj: Journal of Electronic Materials; Jan1991, Vol. 20 Issue 1, p79-90, 12p
Abstrakt: We report a systematic investigation of the amount and nature of residual impurities which incorporate during the epitaxial growth of GaAs performed by vapor phase epitaxy (VPE) under very low pressure conditions. Discussing the results in the light of the electrical data and growth kinetics, we find the following: i) there is a one to one correspondence between the residual level of n-type doping and the total gas pressure achieved during the growth run; ii) the residual donors come from a systematic contamination through the gas lines and are most probably sulfur; iii) accidental contamination processes also rule the amount and nature of residual acceptors which compensate the material but have different origins. All identified shallow species come from the gallium sources: this includes group II (zinc or magnesium) and group IV (carbon) elements. Two deeper ones have been also found: chromium and copper. While chromium comes from an obvious contamination by the semi-insulating (Cr-doped) substrates, copper has an unspecified origin. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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