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Susan Y. Lehman, Alexana Roshko, Richard Mirin, Kristine A. Bertness, Todd E. Harvey, Keith D. Cobry
Abstract
The topography and surface roughness of (100) GaAs substrates and buffers after different preparation procedures were determined from atomic force microscopy measurements. The influence of substrate aging and chemical etching on buffers grown by molecular beam epitaxy was studied as was the effect of different buffer growth procedures. After thermal desorption of the surface oxide, wafers etched in HCl:H2O (1:1) were smother than as received, epi-ready wafers, while wafers etched in H2O2:NH4OH:H2O (3:1:10) were rougher. After as little as 100 nm of buffer growth, there was no significant difference in the roughness on etched or as received substrates. The buffer growth conditions were found to be important to surface roughness. Using a pulsed growth at high temperatures enhanced mounding on the wafer surface, while post-growth annealing at the growth temperature reduced the surface roughness.
Lehman, S.
, Roshko, A.
, Mirin, R.
, Bertness, K.
, Harvey, T.
and Cobry, K.
(2009),
Topography of epitaxial GaAs surfaces for growth, Journal of Crystal Growth, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=32762
(Accessed October 11, 2025)