Nanofaceting of unit cells and temperature dependence of the surface reconstruction and morphology of Si(1 0 5) and (1 0 3)

The well-annealed and quenched Si(1 0 5), (1 0 4), (1 0 3), and (3 1 9) surfaces have been studied with LEED and STM, and it turns out that the morphology and reconstruction of all these surfaces exhibit a rich temperature dependence, especially for Si(1 0 5). A technique based on LEED pattern analysis has been developed, which can tell if the unit cell of a stable surface consists of nanofacets of other (major) stable surfaces, to discriminate minor from major stable surfaces. By means of this technique, Si(1 0 5) and (1 0 3) have been disclosed to be minor stable surfaces and belong to the (0 0 1) family, and their unit cell structures as well as the step configurations of many reconstructions observed here have been mapped out without invoking models. The rarely seen temperature dependent step configurations of Si(1 0 5) are interpreted as a result of the interplay of the entropic repulsive, short-range attractive, and long-range repulsive step-step interactions. The fact that Si(1 0 3) belongs to the (0 0 1) family whereas Ge(1 0 3) belongs to the (1 1 3) family is attributed to the difference between the surface structure of Ge(1 1 3)3 × 2 and that of the Si(1 1 3)3 × 2.