Epitaxy homoepitaxy

Epitaxy Oriented overgrowth of an atomistically deposited film. See also Epitaxial growth Epitaxy, heteroepitaxy Epitaxy, homoepitaxy. 

Epitaxy, homoepitaxy Oriented overgrowth on a substrate of the same material. Example Silicon on doped silicon. 

C2.18.4.1 HOMOEPITAXY OF GALLIUM ARSENIDE BY ATOMIC LAYER EPITAXY... 

The nature of the deposit and the rate of nucleation at the very beginning of the deposition are affected, among other factors, by the nature of the substrate. A specific case is that of epitaxy where the structure of the substrate essentially controls the structure of the deposit.Plb lP ] Epitaxy can be defined as the growth of a crystalline film on a crystalline substrate, with the substrate acting as a seed crystal. When both substrate and deposit are of the same material (for instance silicon on silicon) or when their crystalline structures (lattice parameters) are identical or close, the phenomena is known as homoepitaxy. When the lattice parameters are different, it is heteroepitaxy. Epitaxial growth cannot occur if these stmctural differences are too great. 

Epitaxy is a term that denotes the growth of a thin crystalline film on a crystalline substrate. When the epitaxial film is of the same material as the substrate (for instance silicon on silicon), the process is known as homoepitaxy. When film and substrate are of different... 

Fundamental to forming high quality structures and devices with thin-films of compound semiconductors is the concept of epitaxy. The definition of epitaxy is variable, but focuses on the formation of single crystal films on single crystal substrates. Homoepitaxy is the formation of a compound on itself. Heteroepitaxy is the formation of a compound on a different compound or element, and is much more prevalent. 

MBE (molecular beam epitaxy), which involves epitaxial growth of thin films on either the same material as substrate (homoepitaxial) or a lattice-matched substrate (heteroepitaxial) the heated substrate reacts with a molecular beam of compounds containing the constituent elements of the semiconductor as well as any dopants the resultant film is essentially a single crystal slow growth rates produce films from a few nanometers thick to at most several hundred nanometers that have very high purity and controlled levels of dopants. 

R. J. Molmr, Hydride Vapor Phase Epitaxial Growth of TTI-V Nitrides T. D. Moustakas, Growth of III-V Nitrides by Molecular Beam Epitaxy Z. Liliental-Weber, Defects in Bulk GaN and Homoepitaxial Layers C G. Van tie Walk and N. M. Johnson, Hydrogen in III-V Nitrides... 

In molecular beam epitaxy (MBE) [317], molecular beams are used to deposit epitaxial layers onto the surface of a heated crystalline substrate (typically at 500-600° C). Epitaxial means that the crystal structure of the grown layer matches the crystal structure of the substrate. This is possible only if the two materials are the same (homoepitaxy) or if the crystalline structure of the two materials is very similar (heteroepitaxy). In MBE, a high purity of the substrates and the ion beams must be ensured. Effusion cells are used as beam sources and fast shutters allow one to quickly disrupt the deposition process and create layers with very sharply defined interfaces. Molecular beam epitaxy is of high technical importance in the production of III-V semiconductor compounds for sophisticated electronic and optoelectronic devices. Overviews are Refs. [318,319],... 

Epitaxy The deposition of a single-crystal film of a material upon a template of atoms provided by the surface of a crystalline solid called the substrate. Such a film is termed an epitaxial layer If the film and substrate are composed of materials having the same lattice parameter, the film is homoepitaxial," and if the film and substrate are formed from materials with different lattice parameters, the film is heteroepitaxial. ... 

Bulk plate shaped GaN crystals do not have threading dislocations along the c-axis which would end at the (0001) surfaces. This is very different in comparison with GaN layer crystals grown on any substrate. It is also important with respect to application of these plates as substrates for homoepitaxial growth, since threading dislocations in a substrate propagate into the epitaxial layers. 

Based on TEM studies of the defects in bulk GaN it appears that this material is suitable as a substrate for epitaxial growth [30]. In addition, optimisation of gas flow and purity, and also cleaning of the bulk surfaces are necessary to obtain high crystal quality in the homoepitaxial layers... 

In this section we are concerned with epitaxial deposition. The word Greek taxis can mean an arrangement or a positioning. The Greek preposition epi in this context means upon. Epitaxial, then, means that the deposited layers are arranged on something namely, the substrate or layers already deposited. The particular arrangement is crystalline. The term epitaxial deposition is reserved for crystalline deposition. Epitaxial is further refined to include homoepitaxial and heteroepitaxial. In homoepitaxial deposition, the deposited material is the same as the substrate silicon on silicon and diamond on diamond are examples of homoepitaxial deposition. In heteroepitaxial deposition the deposited material is different from the substrate diamond on silicon or GaN on sapphire. 

Epitaxial metal deposition — In an epitaxial deposition the crystal lattice of the substrate is continued in the deposit. In homoepitaxy the substrate and the growing film... 

Homoepitaxial metal deposition epitaxial metal deposition... 

It has been widely demonstrated that the preparation of oriented, and in some cases epitaxial films by CSD is possible, despite the relatively large thickness of the films that is deposited in a single step. Lange ° reviewed the various mechanisms that lead to oriented growth, and a variety of factors including reactions at the electrode interface, - organic content within the film," " and the use of seed layers" to promote homoepitaxy have been discussed. The ability to control film properties (remanent polarization, dielectric constant, etc.) through manipulation of film orientation has also been shown. 

When an epitaxial film grows on a substrate of the same nature, one deals with homoepitaxy. If the growth occurs on a different substrate, one deals with heteroepitaxy. 

If two crystals are placed side by side, it is possible to define vector relations that express the characteristic crystallographic directions of one of the ctystals in a set of coordinates defined by the cell of the other crystal. These are referred to as epitaxy relations. By extrapolation, when the grains that comprise a polyctystalUne film all have virtually the same orientation, it is possible to define ctystallographic axes specific to this orientation and to find the relation between these axes and those, for example, of the single ctystal on which the film is deposited. If the film and the substrate share the same ctystal nature, we are dealing with homoepitaxy, otherwise, it is referred to as heteroepitaxy. Epitaxy relations are three-dimensional and therefore they are usually written as follows ... 

Diamond homoepitaxy and heteroepitaxy have been achieved on diamond and cBN, respectively. Epitaxially textured and fiber textured, highly oriented diamond films have been grown on Si(lOO). The feasibility of diamond heteroepitaxy on Ni, Ti, Co and Cu has also been confirmed by several experiments. Diamond can grow on Fe, but not yet by epitaxy. 

Molecular beam epitaxy. Epitaxial techniques are techniques of arranging atoms in single-crystal fashion on crystalline substrates so that the lattice of the newly grown film duplicates that of the substrate. If the film is of the same material as the substrate, the process is called homoepitaxy, epitaxy, or simply epi. The most important applications here are Si epi on Si substrates and GaAs epi on GaAs substrates. If the deposit is made on a substrate that is chemically different, the process is termed heteroepitaxy. An important application is the deposition of silicon on an insulator (SOI) e.g. with sapphire (AI2O3) as the insulator in the silicon on sapphire (SOS) process. 

---