The purpose of this article is to describe the basic physical processes involved in the nucleation and growth of thin films of materials on solid surfaces. In this introduction the three modes of crystal growth which are thought to occur on surfaces in the absence of interdiffusion are described, and the relationships between the thermodynamics of adsorption and the kinetics of crystal growth are explored in general terms. This is followed by a brief review of atomistic nucleation theory, explaining the relations of such theories to experimental observables. In the next three sections, recent experimental examples of these three growth modes are given, which are interpreted where possible in terms of nucleation and growth theory. The last section discusses observations on the shapes of growing crystallites and the relation of such observations to nucleation and surface diffusion processes.

https://iopscience.iop.org/article/10.1088/0034-4885/47/4/002/pdf

Nucleation and growth of thin films

A simple extension of the reflection high‐energy electron diffraction oscillation technique to vicinal surfaces provides a means of studying surface diffusion during molecular beam epitaxial growth. The basis of the method is described and some preliminary results for Ga diffusion during the growth of GaAs films with (001) 2×4 and 3×1 reconstructed surfaces are presented.

Reflection high‐energy electron diffraction oscillations from vicinal surfaces—a new approach to surface diffusion measurements

The atomic structure of the Si(001) surface has been examined with use of scanning tunneling microscopy (STM). The STM images reveal a dimer-type reconstruction and are inconsistent with chain and vacancy models. Both buckled and nonbuckled dimers are observed, giving rise to regions of (2×1), c(4×2), and p (2×2) symmetry. The surface has a high density of vacancy-type defects, which appear to induce or stabilize buckling of the dimers at room temperature. The STM images also reveal the atomic structure at steps and defects. At high annealing temperature the step density increases dramatically, eventually leading to faceting.

Scanning tunneling microscopy of Si(001).

The authors have designed, fabricated, and tested vertical-cavity surface-emitting lasers (VCSEL) with diameters ranging from 0.5 mu m to>50 mu m. Design issues, molecular beam epitaxial growth, fabrication, and lasing characteristics are discussed. The topics considered in fabrication of VCSELs are microlaser geometries; ion implementation and masks; ion beam etching packaging and arrays, and ultrasmall devices. >

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Vertical-cavity surface-emitting lasers: Design, growth, fabrication, characterization

Fundamental processes in Si/Si and Ge/Si epitaxy studied by scanning tunneling microscopy during growth

Detailed observations have been made of the intensity oscillations in the specularly reflected and various diffracted beams in the RHEED pattern during MBE growth of GaAs, Ga
 x
 Al1−x
As and Ge. The results indicate that growth occurs predominantly in a two-dimensional layer-by-layer mode, but there is some roughening, which is enhanced by deviations from stoichiometry and the presence of impurities. In the case of the GaAs (001) −2×4 reconstructed surface a combination of dynamic and static RHEED measurements has provided firm evidence for the presence of one-dimensional disorder features as well as surface steps.

N.G. Norton

Papers

Dynamics of film growth of GaAs by MBE from Rheed observations

Temporal intensity variations in RHEED patterns during film growth of GaAs by MBE

RHEED observations of disorder on Si(001)-(2×1) surfaces