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

SOI by CVD: Epitaxial Lateral Overgrowth (ELO) process—Review

This article provides an overview of area-selective thin film deposition (ASD) with primary focus on vapor-phase thin film formation via chemical vapor deposition (CVD) and atomic layer deposition ...

Area-Selective Deposition: Fundamentals, Applications, and Future Outlook

An ultraclean hot‐wall low‐pressure chemical vapor deposition (CVD) system was developed and Si films were deposited on single‐crystal Si and SiO2 using ultraclean SiH4 and H2 gases in the temperature range 600–850 °C under an ultraclean environment. As a result of ultraclean processing, an incubation period of Si deposition only on SiO2 was found, and low‐temperature Si selective deposition and epitaxy on Si were achieved without addition of HCl under deposition conditions where only nonselective polycrystalline Si growth could be obtained in conventional CVD systems.

Low-temperature silicon selective deposition and epitaxy on silicon using the thermal decomposition of silane under ultraclean environment

The techniques of selective silicon growth (SSG) have already found many applications in device fabrication in respect of both process simplification and the development of novel device structures; the techniques involve selective epitaxial growth (SEG), epitaxial lateral overgrowth (ELO), selective polycrystalline Si growth (SPD) and selective polycrystalline-epitaxial growth (SPEG or SSPD). The basic technique involves substrate preparation to produce the necessary seed windows in an insulating layer together with the subsequent removal of surface damage ( e.g. from a reactive ion etch), ex-situ and in-situ cleaning processes and the selective growth itself. Ex-situ processing generally involves combinations of a wet chemical ( e.g. RCA) clean to remove organics and/or metallics, HF treatment to remove oxide and (hydrogen) passivate the Si surface against reoxidation and/or UV-ozone (UVOC) exposure designed to remove carbon and to provide a thin passivating oxide. The in-situ clean can be a combination of an HF-vapour treatment providing a similar surface to the above, UVOC providing the same treatment as above (but with the production of a relatively thinner passivating oxide which is more easily desorbed at low temperatures), followed by some sort of plasma clean or a H 2 bake to remove the surface oxide prior to growth; however, depending upon the particular reactor system being used, an in-situ “pre-bake” may not be necessary if operating under ultrahigh vacuum conditions. The ex-situ and in-situ cleaning procedures should provide substrate surfaces adequate for SSG with minimal undercutting of the field area mask. The growth process involves optimization of temperature, pressure and gas flows to obtain full control over selectivity ( i.e. polycrystalline Si nucleation on the field), side-wall faceting and defect generation and must also consider autodoping effects for device applications. This paper will review the techniques of surface preparation and SSG and discuss the results obtained from a study of SEG and ELO for advanced bipolar applications, using a modified Applied Materials 7811 epitaxial reactor system.

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The selective epitaxial growth of silicon

The growth of polycrystalline silicon layers on and substrates can be hampered in the early stages of growth by the presence of different species adsorbed on the surface In this article nucleation experiments with silicon on and are described in the system at temperatures between 600° and 900°C In this temperature regime (and without addition) the saturation nucleus density of silicon clusters on substrates shows a decrease in density with decreasing temperature, whereas on substrates the opposite occurs Experiments with nitrogen as a carrier gas, however, give almost the same saturation nucleus densities of silicon clusters on and substrates Additions of to the system produce a decrease in the nucleus saturation density on and substrates, and the density also decreases with decreasing temperatures below 900°C It is further shown that selective growth of silicon on partly coated silicon substrates becomes more difficult at lower growth temperatures Adsorption of different surface species (H, Cl, , and ) on and substrates is discussed and it is concluded that a strong adsorption of atomic hydrogen, notably on surfaces, may explain the difference in nucleus densities on and substrates at temperatures below 900°C

W. A. P. Claassen

Papers

The Nucleation of CVD Silicon on SiO2 and Si3 N 4 Substrates III . The System at Low Temperatures