Atomic structure of the interface between silicon (111) and amorphous germanium

Abstract

The structure of the transition region between crystalline Si(111) and amorphous germanium has been studied by means of quantitative high-resolution electron microscopy. Using iterative image matching techniques the two-dimensional distribution function of germanium atoms in the transition region has been determined from focal image series of such interfaces. The distribution function reveals lateral ordering close to the crystalline substrate in addition to a pronounced layering usually observed for solid-liquid interfaces. It further shows that the transition region is elastically strained due to the volume misfit between crystalline silicon and amorphous germanium. The width of the transition region is 1.4 nm corresponding to about four (111) layers of crystalline silicon or germanium. Finally, the width of the bond-angle distribution for the first layer of germanium atoms on the silicon substrate is determined as 8.9°which is close to the corresponding value of 9.7°for bulk amorphous germanium.

Crystalline-Vitreous Interface in Two Dimensional Silica

“…4 [4,6,7,14] and experimentally [3,10,20]. However, it is not straightforward to compare these values to our measurements because of the different interface system (silica-silica) and the different dimensionality of the boundary (2D vs 1D).…”

“…Moreover, the application of scanning probe microscopy to a c-a transition has not been shown. These structures were thought to be inaccessible by scanning probe microscopy, because the interfaces are buried inside the bulk materials [3].In a recent publication, we reported on the atomic structure of a thin vitreous bilayer silica film on a Ru(0001) support using low temperature scanning tunneling microscopy (STM) [22]. The film's structure exhibited high short range order, but no long range periodicity.…”

“…The transitional structures were investigated by a large variety of theoretical [1,4,6,8,14,16,17,19] and experimental methods [2,3,5,[9][10][11][12][13]15,18,20,21]. However, the interface between crystalline and vitreous silica has not been addressed so far.…”

“…A vast amount of studies was published concerning crystalline-amorphous (c-a) interfaces of different, mostly tetrahedrally coordinated materials, including c-Ge=a-Ge [1], c-Si=a-Ge [2,3], c-Si=a-Si [1,[4][5][6][7], c-Al 2 O 3 =a-CaSiO 3 [8], c--Si 3 N 4 =a-SiO 2 [9], and c-Si=a-SiO 2 [10][11][12][13][14][15][16][17][18][19][20][21], the last example being an important interface in semiconductor technology. The transitional structures were investigated by a large variety of theoretical [1,4,6,8,14,16,17,19] and experimental methods [2,3,5,[9][10][11][12][13]15,18,20,21].…”

Well-Ordered Molybdenum Oxide Layers on Au(111): Preparation and Properties

“…A vast amount of studies was published concerning crystalline-amorphous (c-a) interfaces of different, mostly tetrahedrally coordinated materials, including c-Ge=a-Ge [1], c-Si=a-Ge [2,3], c-Si=a-Si [1,[4][5][6][7], c-Al 2 O 3 =a-CaSiO 3 [8], c--Si 3 N 4 =a-SiO 2 [9], and c-Si=a-SiO 2 [10][11][12][13][14][15][16][17][18][19][20][21], the last example being an important interface in semiconductor technology. The transitional structures were investigated by a large variety of theoretical [1,4,6,8,14,16,17,19] and experimental methods [2,3,5,[9][10][11][12][13]15,18,20,21]. However, the interface between crystalline and vitreous silica has not been addressed so far.…”