The roughening of (100) surfaces at low temperatures during electron cyclotron resonance H plasma cleaning was studied in an ultra-high vacuum environment. The effects of process parameters upon the surface roughness were analyzed by means of atomic force microscopy and reflection high-energy electron diffraction. The defect morphology was studied by means of transmission electron microscopy in order to understand its effect upon surface roughness. It was found that the latter was strongly related to the nucleation and growth of {111} platelet defects in the Si sub-surface region, and to preferential etching at points where the {111} platelet defects intersected the surface. It was concluded that the H ion flux and substrate temperature could be successfully used to tailor the {111} platelet defects and, thereby, the surface roughness.

K.H.Hwang, E.Yoon, K.W.Whang, J.Y.Lee: Applied Physics Letters, 1995, 67[24], 3590-2