PLANARIZATION OF EPITAXIAL GAAS OVERGROWTH OVER TUNGSTEN WIRES

We report on thin GaAs epitaxial overgrowth over tungsten wires. The a im of the study is to overgrow the grating without the formation of vo ids above the tungsten wires and to investigate the planarization of t he growth front over the grating. It is established that the most impo rtant factors for rapid planarization of the overgrowth for given epit axial conditions are the crystallographic orientation of the grating, the grating period, and the ratio of the growth rates for the differen t facets formed in the growth front. For a 300 nm period grating and a metal width of 100 nm, a planarized growth front is demonstrated afte r 200 nm of growth. (C) 1996 American Institute of Physics.