Analysis of the growth modes for gallium arsenide metalorganic vapor-phase epitaxy

D. C. Law, L. Li, M. J. Begarney, R. F. Hicks
2000 Journal of Applied Physics  
The surface roughness of gallium arsenide ͑001͒ films produced by metalorganic vapor-phase epitaxy has been studied as a function of temperature and growth rate by in situ scanning tunneling microscopy. Height-height correlation analysis reveals that the root-mean-height difference follows a power-law dependence on lateral separation, i.e., ⌫(L)ϭkL a , up to a critical distance L c , after which it remains constant. For layer-by-layer growth, the roughness exponent, ␣, equals 0.25 Ϯ0.05,
more » ... the critical distance increases from 50 to 150 nm as the substrate temperature increases from 825 to 900 K. The roughness exponent jumps to 0.65Ϯ0.1 upon transitioning to three-dimensional island growth. By relating the height-height correlation analysis to the Einstein diffusivity relationship, the activation energy for gallium surface diffusion has been estimated: E d ϭ1.35Ϯ0.1 eV.
doi:10.1063/1.373687 fatcat:yermrq5wgnbxfggqzvnb7rlxje