Effects of Substrate Temperature and Atomic Hydrogen Flow on the Mircocrystallinity of Evaporated Hydrogenated silicon Films

2002 ◽  
Vol 715 ◽  
Author(s):  
A.J. Stoltz ◽  
Whitney Mason ◽  
J.D. Benson ◽  
J.H. Dinan ◽  
K. McCormack ◽  
...  

AbstractAs a first step toward an understanding of the chemical and structural role of hydrogen in hydrogenated amorphous silicon, we utilized electron beam evaporation in an ultra high vacuum environment to deposit films of amorphous silicon and systematically dosed these films with atomic hydrogen during deposition. Secondary Ion Mass Spectroscopy (SIMS) data indicated that hydrogen concentration can be varied from the detection limit of SIMS to a value in excess of 1021 atoms cm-3. The intentional addition of hydrogen caused the concentration to fall from in an excess of 1021 atoms*cm-3 to below 1018 atoms*cm-3.

2000 ◽  
Vol 609 ◽  
Author(s):  
Satoshi Yamasaki

ABSTRACTThe in-situ ESR technique is applied to a plasma-enhanced chemical vapor deposition (PECVD) system in order to investigate the surface microchemical reactions during the growth of hydrogenated amorphous silicon (a-Si:H) and plasma treatments of H2 and Ar gases on a- Si:H. The growth model of a-Si:H and the role of H atoms on a-Si:H films are discussed using the experimental results. The recent results on the dynamic surface reactions of crystalline silicon with oxygen molecules in an ultra-high-vacuum ESR system are introduced.


Author(s):  
Julien Fontaine

Some hydrogenated amorphous carbon (a-C:H) films have the peculiarity to exhibit coefficients of friction in the millirange, known as “superlow friction”, under inert environments like dry nitrogen or high vacuum. However, this “superlubricity” is only observed for some coatings and sometimes for very short duration. The role of tribofilm in the superlow friction regime observed on various a-C:H films sliding against steel pins has been investigated by performing experiments in ultra-high vacuum and hydrogen ambient. Tribofilm build-up appears to be controlled by interactions with oxide layers. Then, evolutions of the tribofilm will depend both on the composition of a-C:H film and on interactions with environment, through tribochemical reactions. Furthermore, the mechanical properties of the films are correlated with the achievement of superlow friction. All these results suggest that surface rheological properties are of critical importance in reaching superlow friction regime with a-C:H films.


Author(s):  
J. E. O'Neal ◽  
J. J. Bellina ◽  
B. B. Rath

Thin films of the bcc metals vanadium, niobium and tantalum were epitaxially grown on (0001) and sapphire substrates. Prior to deposition, the mechanical polishing damage on the substrates was removed by an in-situ etch. The metal films were deposited by electron-beam evaporation in ultra-high vacuum. The substrates were heated by thermal contact with an electron-bombarded backing plate. The deposition parameters are summarized in Table 1.The films were replicated and examined by electron microscopy and their crystallographic orientation and texture were determined by reflection electron diffraction. Verneuil-grown and Czochralskigrown sapphire substrates of both orientations were employed for each evaporation. The orientation of the metal deposit was not affected by either increasing the density of sub-grain boundaries by about a factor of ten or decreasing the deposition rate by a factor of two. The results on growth epitaxy are summarized in Tables 2 and 3.


2005 ◽  
Vol 239 (3-4) ◽  
pp. 327-334 ◽  
Author(s):  
Ming Zhu ◽  
Peng Chen ◽  
Ricky K.Y. Fu ◽  
Weili Liu ◽  
Chenglu Lin ◽  
...  

1985 ◽  
Vol 49 ◽  
Author(s):  
Martin Stutzmann ◽  
Warren B. Jackson ◽  
Chuang Chuang Tsai

AbstractThe dependence of the creation and the annealing of metastable dangling bonds in hydrogenated amorphous silicon on various material parameters will be discussed in the context of a recently proposed model. After a brief review of the kinetic behaviour governing defect creation and annealing in undoped a- Si:H, a number of special cases will be analyzed: the influence of alloying with O, N, C, and Ge, changes introduced by doping and compensation, and the role of mechanical stress. Finally, possibilities to increase the stability of a-Si:H based devices will be examined.


1981 ◽  
Vol 52 (12) ◽  
pp. 7275-7280 ◽  
Author(s):  
Shunri Oda ◽  
Keishi Saito ◽  
Hisashi Tomita ◽  
Isamu Shimizu ◽  
Eiichi Inoue

1989 ◽  
Vol 160 ◽  
Author(s):  
Nigel M. Jennett ◽  
D.J. Dingley ◽  
Y. Ando

AbstractBilayers of Cu/Fe and Cu/V and multilayers of Ni/Fe have been grown under high vacuum and ultra high vacuum conditions respectively with [111] epitaxy. Multilayer layer thicknesses ranged from 3 monolayers to 15 monolayers per layer. Improved epitaxy of the UHV growth was, we believe, due to the better vacuum although perfect material could only be obtained for growth within a narrow and shifting substrate temperature ‘window’. Possible shortfall in the quality of the Cu backing layer epitaxy was averted by a 2hr anneal at 425°C.In the Fe/Ni multilayers the Fe was observed to adopt the FCC lattice rather than the equilibrium BCC lattice for layer thicknesses less than 10 monolayers. This change of structure coincided with a reduction in sample magnetic moment per volume attributed to a collapse of the Fe moment to a value 7 times less than bulk.


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