Epitaxial Growth of CuAu–Ordered CuInSe2 Structural Polytypes by Migration Enhanced Epitaxy

1999 ◽  
Vol 583 ◽  
Author(s):  
B. J. Stanbery ◽  
C.-H. Chang ◽  
S. Kim ◽  
S. Kincal ◽  
G. Lippold ◽  
...  

AbstractMigration-Enhanced Epitaxy (MEE) has been successfully employed to grow epitaxial films of the ternary compound CuInSe2 on (001) GaAs that are ordered in a CuAu crystallographic structure rather than the compound's equilibrium chalcopyrite structure. Evidence for this structural polytype is provided by XRD, TEM–TED, and Raman scattering data. Film growth under the conditions employed for this study occurs in a Stranski-Krastanov mode. The effects of growth system parameters and overall stoichiometry on 3–D island formation are described, including our observation that ordering of those islands into quasiperiodic self-assembled arrays occurs only in the case of nonstoichiometric copper excess.

Author(s):  
J. S. Maa ◽  
Thos. E. Hutchinson

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.


2012 ◽  
Vol 1426 ◽  
pp. 331-337
Author(s):  
Hiroshi Noge ◽  
Akira Okada ◽  
Ta-Ko Chuang ◽  
J. Greg Couillard ◽  
Michio Kondo

ABSTRACTWe have succeeded in the rapid epitaxial growth of Si, Ge, and SiGe films on Si substrates below 670 ºC by reactive CVD utilizing the spontaneous exothermic reaction between SiH4, GeH4, and F2. Mono-crystalline SiGe epitaxial films with Ge composition ranging from 0.1 to 1.0 have been successfully grown by reactive CVD for the first time.This technique has also been successfully applied to the growth of these films on silicon-on-glass substrates by a 20 - 50 ºC increase of the heating temperature. Over 10 μm thick epitaxial films at 3 nm/s growth rate are obtained. The etch pit density of the 5.2 μm-thick Si0.5Ge0.5 film is as low as 5 x 106 cm-2 on top. Mobilities of the undoped SiGe and Si films are 180 to 550 cm2/Vs, confirming the good crystallinity of the epitaxial films.


1991 ◽  
Vol 237 ◽  
Author(s):  
Harry A. Atwater ◽  
C. J. Tsai ◽  
S. Nikzad ◽  
M.V.R. Murty

ABSTRACTRecent progress in low energy ion-surface interactions, and the early stages of ion-assisted epitaxy of semiconductor thin films is described. Advances in three areas are discussed: dynamics of displacements and defect incorporation, nucleation mechanisms, and the use of ion bombardment to modify epitaxial growth kinetics in atrulysurface-selective manner.


1998 ◽  
Vol 533 ◽  
Author(s):  
A. Morrya ◽  
M. Sakuraba ◽  
T. Matsuura ◽  
J. Murota ◽  
I. Kawashima ◽  
...  

AbstractIn-situ heavy doping of B into Si1-xGex epitaxial films on the Si(100) substrate have been investigated at 550°C in a SiH4(6.0Pa)-GeH4(0.1−6.0Pa)-B2H6(1.25 ×10−5−3.75 × 10−2Pa)-H2(17–24Pa) gas mixture by using an ultraclean hot-wall low-pressure CVD system. The deposition rate increased with increasing GeH4 partial pressure, and it decreased with increasing B2H6 partial pressure only at the higher GeH4 partial pressure. As the B2H6 partial pressure increased, the Ge fraction scarcely changed although the lattice constant of the film decreased. These characteristics can be explained by the suppression of both the SiH4 and GeH4 adsorption/reactions in a similar degree due to B2H6 adsorption on the Si-Ge and/or Ge-Ge bond sites. The B concentration in the film increased proportionally up to 1022cm3 with increasing B2H6 partial pressure.


1992 ◽  
Vol 275 ◽  
Author(s):  
Julia M. PhUlips ◽  
M. P. Siegal ◽  
S. Y. Hou ◽  
T. H. Tiefel ◽  
J. H. Marshall

ABSTRACTEpitaxial films of Ba2YCu3O7-δ (BYCO) as thin as 250 å A and with Jc's approaching those of the best in situ grown films can be formed by co-evaporating BaF2, Y, and Cu followed by a two-stage anneal. These results extend the work on films > 2000 Å thick by R. Feenstra et al. [J. Appl. Phys. 69, 6569 (1991)]. High quality films of these thicknesses become possible if low oxygen partial pressure [p(O2) = 4.3 Torr] is used during the high temperature portion cf the anneal (Ta). The BYCO melt line is the upper limit for Ta. The use of low p(O2) shifts the window for stable BYCO film growth to lower temperature, which allows the formation of smooth films with greater microstructural disorder than is found in films grown in p(O2) = 740 Torr at higher Ta. The best films annealed in p(O2)=4.3 Torr have Jc values a factor of four higher than do comparable films annealed in P2=740 Torr. The relationship between the T required to grow films with the strongest pinning force and p(O2) is log independent of growth method (in situ or situ) over a range of five orders of magnitude of P(O2).


2010 ◽  
Vol 117 ◽  
pp. 55-61
Author(s):  
Masao Kamiko ◽  
Ryoichi Yamamoto

The effects of several surfactants on the homoepitaxial and heteroepitaxial growth of metallic films and multilayers have been studied and compared. Our measurements clearly revealed that pre-deposition of a small amount of surfactant prior to the adatom deposition changed thin film growth mode and structure. The pre-deposited surfactant enhanced layer-by-layer (LBL) growth of the homoepitaxial and heteroepitaxial growth of metallic films. The surfactant also enhanced the epitaxial growth of metallic multilayer.


1987 ◽  
Vol 101 ◽  
Author(s):  
Hirohide Nakamatsu ◽  
Kazuhiko Hirata ◽  
Shichio Kawai

ABSTRACTArF exciraer laser CVD was performed to give epitaxial SiC films on the sapphire or (α-A12O3 (0001) substrate. The rate of film growth was limited by the diffusion of the supplied gases. Small amounts of the gas supply failed to produce the SiC deposition and etched the substrate. The UV light irradiation of the substrate was necessary for the photo-excitation to grow the adherent epitaxial films. Filtered UV light from a D2 lamp revealed that the light with the wavelength shorter than about 310nm was effective for the epitaxial growth. It was found to be essential to excite intermediate products or by-products in the absorbed layer on the substrate. The epitaxial SiC films on the αA12O3 gave blue photoluminescence which may be ascribed to the superstructure of 3C-type SiC crystals.


2019 ◽  
Vol 80 (11) ◽  
pp. 2013-2026 ◽  
Author(s):  
Lakshmi Machineni

Abstract The treatment of wastewater for reuse is a potential solution to meet ever increasing urban, industrial, agricultural, and environmental demands across the world, where clean water availability is scarce. There are several traditional wastewater treatment processes that offer varying degrees of effectiveness in addition to presenting environmental, economic, and social disadvantages. Development of promising and inexpensive technologies to provide the reusable water in needful amounts using wastewaters as a cheap source of key nutrients and organic matter is required. Wastewater treatment by biological methods is becoming more important in the light of recovering value-added plant nutrients, heavy metals, biosolids, and bioenergy resources. Different types of solid contaminants in effluents can be removed simultaneously by pure cultures or mixed microbial consortia. Based on the structural organization of microbial biomass, biological treatment systems are classified into two types: dispersed growth system and attached growth system. Biological treatment methods associated with fixed-film growth have been recognized as highly effective and more energy efficient than suspended growth systems. This review discusses the recent breakthroughs in advanced biological wastewater treatment using both the systems, and also focuses on key energetic resources recovery driven by biological technologies.


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