Non-epitaxial growth

H. J. Choi and R. Weil, The transition from epitaxial to non-epitaxial growth in electro-deposited Ni, 1981, pp 169. 

Figure 3. Preparation method of non-epitaxial growth Ll0-phase FePt X nanocomposite films.

It has been reported that the carbon concentration in the gas phase should also be controlled during deposition in order to achieve step-flow growth. When the carbon concentration in the gas phase exceeds the ability of the surface steps to incorporate the carbon atoms, abnormal nucleation occurs on the surface terraces, and this results in non-epitaxial growth [12]. For a (100) diamond substrate, non-epitaxial growth can be seen as a pyramidal hillock, which consists of (ill) facets [9,12]. In order to obtain homoepitaxial BDD thin films of high quality, the carbon concentration in the gas phase should be low, however, low carbon concentration also leads to a low growth rate. Therefore, the carbon concentration should be optimized and controlled [13]. 

The physical stmcture of mixed-layer minerals is open to question. In the traditional view, the MacEwan crystallite is a combination of 1.0 nm (10 E) non-expandable units (iUite) that forms as an epitaxial growth on 1.7 nm expandable units (smectite) that yield a coherent diffraction pattern (37). This view is challenged by the fundamental particle hypothesis which is based on the existence of fundamental particles of different thickness (160—162). 

If neither the AC nor the BC component exhibits in any part of its (zero pressure) (x, T) phase diagram the structure a, which though exists in their solid solution, then the latter is of Type III . In this case, the alloy environment stabilizes a structure which is fundamentally new to at least one of its components. Such alloy-stabilized phases with no counterpart in the phase diagram of the constituent components can be formed in bulk equilibrium growth and may be distinguished from the unusual alloy phases that are known to form in extreme non-equilibrium growth methods and in epitaxial forms. 

PIBT of Cr-implanted Si results in full crystallization of the Si layer at fluencies up to MO cm. Precipitates of chromium silicide with semiconductor type of absorption (probably CrSi2) are formed at the depth more than 20 nm by data of optical and Raman spectroscopy. The increase of implantation fluence up to 6-1 o cm results in an increase of the precipitate density up to 6T0 cm increase of roughness (up to 6.9 nm). The subsequent Si growth was non-epitaxial. 

The investigation of epitaxial Si growth atop atomically-clean Si surface implanted with Fe" (Cr ) ions and subjected to PLA or PIBT was carried out. It was established that epitaxial Si growth by MBE is possible for minimal fluence by mechanism of 2D nucleation and lateral 3D growth. The continuous epitaxial Si films can be obtained larger than 500 nm at 700°C for small implantation fluence of Fe and Cr ( 10 cm ). For the maximal fluence (6-10 cm ) the number of pinholes in the Si layer increases sharply and epitaxial growth is failed. In the case of the Si growth (up to 500 nm) on the surface of non-annealed samples the pinhole density increases for 3-4 times and Si layer is polycrystalline only. 

Nevertheless few results have been obtained concerning their epitaxial growth. Electrodeposition of epitaxial CdSe quantum dots on gold single crystals has been reported [218, 219]. In the same way epitaxial layers of CdTe [220] and CdSe [221] have been electrodeposited on (111) InP. Using cyclic voltammetry K. Rajeshwar [222] has electrosynthesized CdSe/ZnSe superlattices (non epitaxial). XPS depth profiles have clearly demonstrated the modulation in the Cd and Zn content. 

The success of the non-equilibrium CVD growth technique for the homo- and hetero-epitaxial growth of SiC has been the major thrust of the last decade. Many of the potential applications of SiC in semiconductor electronics depend upon ion-implantation techniques for device fabrication. Several authors [101-118] have reported studies of the lattice damage induced by ion-implantation or by fast-particle irradiation, and of lattice damage recovery, after the seminal work of Makarov [119]. 

Hydrogen [1] and HC1 [10] at high temperatures, above 1350°C, etch SiC. Hydrogen etching is useful in cleaning the surface prior to epitaxial growth and appears to be non-preferential. 

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