Anisotropic and Selective Grain Growth during Ohmic Contact Formation
Authors: Xie, Qianghua; Fejes, Peter; Le, Ha; Lan, Ellen
Source: Journal of Electronic Materials, Volume 31, Number 12, 1 December 2002 , pp. 1357-1361(5)
Abstract:We examine the grain formation during annealing of metallic contacts on multiple semiconductor layers by transmission electron microscopy (TEM). The system investigated is Ni/Ge/Au on GaAs/InGaP/InGa(Al)As. Heterointerfaces set vertical limits for the growth of various grains leading to an evident anisotropic lateral-grain expansion. The Au-containing grains selectively locate in the proximity of the InGaAs layer. Using nanoprobe x-ray energy-dispersive spectrum (EDS) analysis, the compositions of those different types of grain have been determined. The microstructure of the grains correlates with the contact resistance and on-resistance of the devices.
Document Type: Miscellaneous
Publication date: December 1, 2002