The generation of pyramidal hillocks on (111) surfaces which were 0.55 off [111] was investigated during chemical vapor deposition from SiH2Cl2. The hillocks could be classified into 3 types: bright-top, sharp-top and flat-top. It was shown that the flat-top hillocks were based upon stacking faults while the sharp-top and bright-top hillocks resulted from hydrocarbon and oxide contaminants on the substrate, respectively. The sharp-top hillocks developed along dislocations. The generation kinetics of the stacking fault were suggested to be associated with Cl adsorption at the surface. Because of the large hillock size, the existence of growth defects due to stacking faults and dislocations could be detected easily in thin films, with no etching. It was found that the 3 kinds of hillock could be drastically reduced in density by using carrier H gas which was excited with ultra-violet light from low-pressure Hg lamps during growth, as well as by substrate cleaning at atmospheric pressure. It was concluded that the photo-excited H had a cleansing effect upon hydrocarbons, oxides and Cl on the surface during Si growth.

Y.Takakuwa, M.K.Mazumder, N.Miyamoto: Journal of the Electrochemical Society, 1994, 141[9], 2567-72