A review of the geometrical fundamentals of reflection high-energy electron diffraction with application to silicon surfaces

Abstract

Reflection high-energy electron diffraction (RHEED) is an experimentally simple technique, and yet a powerful one for examining the structure of a substrate surface and for monitoring the surface crystal structure and the crystallographic orientation of thin films during their growth. However, it can be difficult to learn to interpret the RHEED patterns of new materials, because a practical and adequately detailed introduction to the technique is not generally available. To address this need, we develop the geometrical principles of RHEED; using the kinematic approximation, we show how a particular point of the sample surface’s reciprocal net gives rise to a diffraction maximum at a particular location on the RHEED viewing screen. We explain the origins of ‘‘reciprocal lattice rods,’’ RHEED streaks, and Laue rings. We show how to calculate the streak spacing, and clarify the basic effect on the RHEED pattern of using a nonzero angle of incidence for the incident beam. Crystalline nets, reciprocal nets, and their RHEED patterns are derived for both (001) and (111) silicon surfaces and are compared to experimentally obtained patterns.

Epitaxial orientation of β-FeSi2/Si heterojunctions obtained by RTP chemical vapor deposition

“…Considering now TED along the [1][2][3][4][5][6][7][8][9][10] Si axis, it must be noted that the theoretical diagram presented in figure 5b has never been observed in our samples and to our knowledge, it has never been observed in the literature. Indeed, the most commonly observed epitaxial relation is presented in figure 12 Concerning the deposition on a (001) silicon substrate the situation seems to be simpler since only the (100) /3-FeSÎ2 plane presents an acceptable mismatch.…”

“…Two possible azimuthal orientations have already been described by J.E. Mahan [5]. They are designated (Fig.…”

“…Data show that the natural crystal is very imperfect: numerous crystal twinnings and microplanar defects identified as intrinsic stacking faults have been reported [2,3]. (111) and (001) silicon substrates [4][5][6]. The In this work chemical vapor deposition (CVD) was used to grow stoichiometric 3-FeSi2 using Rapid Thermal Processing which has been termed Limited Reaction Processing (LRP) [7].…”

“…In this case the epitaxial relationships (Fig. 2) Cross-sectional information is obtained along Si and [1][2][3][4][5][6][7][8][9][10] Si. Conventional TEM observations confirm the 100 nm mean thickness of the 0-FeSi2 layers and indicate their continuity (Fig.…”

Reflection high-energy electron diffraction patterns of CrSi2 films on (111) silicon

“…CrSi 2 is a narrow bandgap semiconductor with a forbidden energy gap near 0.3 e V. 13 The quest for epitaxial CrSi 2 films on silicon has attracted more attention than that of perhaps any other semiconducting silicide. 4 -7 This effort was encouraged by a promising theoretical lattice match of the hexagonal CrSi 2 basal planes to the Si ( 111 ) face.…”