we determined that each facet makes an angle of 26 u00b0 u00b1 5 u00b0 with the sample normal indicating that the facets are vicinal lt 311 gt planes the continued growth of the roughened surface shows that the epitaxy on the lt 311 gt surface is possible by this technique the reconstructed si lt 311 gt surface is a low energy surface see j dabrowski h mussig and g wolff phys rev lett 73 1660 1994 and is reached at a lower angle surface roughness than the even more stable lt 111 gt surface the large effective roughness caused by this microstructure formation dramatically reduces the specular and total reflectivity of the films as shown in fig3 b the film appears rough upon visual inspection to study the t dependence of the crystalline phase of the film growth a series of 2 u03bcm thick films were grown onto lt 100 gt 1 5 u03c9 cm n type c si substrates at temperatures between 519 u00b0 c and 610 u00b0 c xrd analysis of these films is shown in fig4 the inset of fig4 shows the entire xrd spectrum linear scale of the films grown at the highest and lowest temperatures the dominant peak in the xrd spectra at all temperatures is the 400 silicon peak at 69 1 u00b0 c with contributions from both the lt 100 gt substrate and at some temperatures from lt 100 gt epitaxy the main panel of fig4 expands the 25 u00b0 lt 2 u03b8 lt 55 u00b0 xrd spectra a perfect epitaxial film would show no peaks at these angles as observed in the film grown at 610 u00b0 c the films grown at lower temperatures all.