Structure of Ge(113): Origin and Stability of Surface Self-Interstitials

Abstract

Using atomic-resolution scanning tunneling microscopy and first-principles calculations we show that Ge and Si(113) are structurally similar, contrary to previous reports. Both surfaces have (3 3 2) and (3 3 1) reconstructions stabilized by surface self-interstitials, with the (3 3 2) lower in energy on Si but degenerate with the (3 3 1) on Ge. Statistical analysis of fluctuations observed between the two structures on Ge, combined with calculations for bulk interstitials, indicate that the surface (not the bulk) is the likely source and sink of the surface self-interstitials for both materials.[ S0031-9007(98)

Strain-induced Ge segregation on Si at high temperatures

“…1 (1 1 1) is less than 301. The {3 1 1} facets are most stable and are always observed on sidewalls of Ge and Si islands [27][28][29][30][31]. Facets, such as {3 3 1} and {23 15 3} were classified as MAJOR for Ge [28].…”

Ge molecular beam epitaxy on Si(113): surface structures, nanowires and nanodots

“…On the clean Ge(113) surface there is no epitaxial compression and the surface energies for 3 ð 2 and 3 ð 1 are degenerate. 12 Because there is nothing in compression between the reconstructed top layer and the substrate, we would like to conclude that the Ge/Si(113) of 1 ML of Ge presents a surface similar to clean Ge. The Ge layer reconstructs into an adsorption structure on the Si surface, and its tension may be relieved effectively by the interface compressive strain.…”

Structure and stability of theSi(331)−(12×1)surface reconstruction investigated with first-principles density functional theory

“…Very similar pentagons were observed earlier on the reconstructed Si͑110͒ and Ge͑110͒ surfaces. [6][7][8] Inspired by structural elements encountered on Si͑113͒ and Ge͑113͒ surfaces, [9][10][11] An et al 6 have proposed an adatom-tetramer-interstitial ͑ATI͒ model for the Si͑110͒-͑16ϫ 2͒ reconstruction containing silicon pentamers as building blocks which explain the pentagons observed in STM images. The stability of the ATI model has subsequently been tested theoretically by means of first-principles total energy calculations.…”