Investigation of Hydrogen and Nitrogen Thermal Stability in PECVD a-Sinx:H.

1992 ◽  
Vol 258 ◽  
Author(s):  
M. Fitzner ◽  
J.R. Abelson ◽  
J. Kanicki

ABSTRACTWe study the high temperature (≤1300°C) thermal evolution from hydrogenated amorphous silicon nitride (a-SiNx:H) films prepared by plasma enhanced chemical vapor deposition. Two principle peaks are found, one at 525–750°C associated with hydrogen release, and one at ≥950°C from hydrogen and nitrogen release. In nitrogen-rich films (x>4/3), the low temperature (525°C) peak intensity is smaller compared to silicon-rich films (x≤4/3), implying that hydrogen is more thermally stable in N-rich films. Helium dilution during film growth further reduces the low temperature peak intensity, producing the most thermally stable N-rich material, with the onset of hydrogen evolution occurring at ∼600°C. For a nitrogen-rich film, high temperature hydrogen evolution began at ∼900°C and was accompanied by nitrogen evolution starting at ∼950°C. UV-illumination of N-rich samples prior to thermal evolution produced no observable changes in the evolution spectra.

1995 ◽  
Vol 406 ◽  
Author(s):  
H. L. Hsiao ◽  
K. C. Wang ◽  
L. W. Cheng ◽  
A. B. Yang ◽  
T. R. Yew ◽  
...  

AbstractThe polycrystalline silicon films were deposited by electron cyclotron resonance chemical vapor deposition (ECR-CVD) with hydrogen dilution at 250°C and without any thermal annealing. The surface morphology and the microstructure of the poly-Si films are investigated by atomic force microscopy (AFM), plan-view transmission electron microscopy (TEM), crosssectional TEM and high resolution TEM (HRTEM). The low temperature poly-Si films deposited by ECR-CVD show a special leaf-like grain shape (plan-view) and an upside-down cone shape (3-dimensional view). The grains in the poly-Si films have preferred orientation of <112> and the longer side of the leaf-like grain is direction and the shorter side is direction. Lattice bending and interruption are found in the films. The arrangement of the atoms on the grains are well ordered, while atoms in the interfacial regions are randomly distributed. A simple grain formation model based on growth rate differences between different planes and etching effect can explain the film growth mechanism and the formation of the special grain geometry.


1986 ◽  
Vol 70 ◽  
Author(s):  
T. Shimizu ◽  
M. Kumeda ◽  
A. Morimoto ◽  
Y. Tsujimura ◽  
I. Kobayashi

ABSTRACTProperties of a-Si1-xGex:H films prepared by magnetron sputtering (MG) and glow discharge decomposition (GD) were compared by means of NMR, ESR, IR and hydrogen-evolution measurements. For MG films, the content of dispersed H is roughly independent of x while the content of clustered H decreases with x. For GD films, both the contents of dispersed and clustered H decrease with x. ESR results reveal that most defects in the films are Ge dangling bonds and that the number of dangling bonds per Ge atom is roughly independent of x for MG films whereas it increases largely with x for GD films. Therefore the content of dispersed H has a good correlation with the number of Ge dangling bonds per Ge atom in a-Si1-xGex:H films. The ratio of the intensity of the IR peak at 2100 cm-1 to that at 2000 cm-1 decreases and increases with x, respectively, for MG and GD films, and the ratio of the intensity of the low temperature H evolution peak to that of the high temperature H evolution peak decreases and increases with x, respectively for MG and GD films.


1993 ◽  
Vol 335 ◽  
Author(s):  
Hideaki Zama ◽  
Jun Saga ◽  
Takeo Hattor ◽  
Shunri Oda

AbstractLow-temperature growth of YBa2Cu3Ox films by metalorganic chemical vapor deposition using N2O as an oxidizing agent has been investigated. We have deposited superconducting YBa2Cu3Ox on (100)MgO substrates at 500°C for the first time. Films of 15nm-thick show zero-resistivity critical temperature of 80K. Films of as thin as three unit-cell-thick reveal the superconducting onset characteristics. This result suggests that superconductivity is arisen even from effectively monomolecular layer of YBa2Cu3Ox when we take into account monomolecular buffer layer and monomolecular cap layer. YBa2Cu3Ox films of 9nm-thick grown on (100)SrTiO3 at 600°C with Tc(zero) of 79K and with peak to valley roughness fluctuation of two unit-cell have been obtained.


2018 ◽  
Vol 32 (22) ◽  
pp. 1850257 ◽  
Author(s):  
Yan Wei ◽  
Da Wei Zhang ◽  
Jun Wang ◽  
Hong Zhong Cai ◽  
Xu Xiang Zhang ◽  
...  

The deposition kinetics and microstructure of chemical vapor deposition (CVD) of Nb on the Mo substrate at different deposition variables is investigated. The morphology of CVD Nb is columnar, it exhibits a strong preferred orientation and its growth direction is perpendicular to the substrate surface, the deposition rate and grain size increased with the increase of deposition temperature. The deposition rate conforms to the Arrhenius formula, the activation energy [Formula: see text] at high temperature and low temperature is 0.85 kJ/mol and 7.2 kJ/mol, respectively. The rate-limiting step for CVD Nb at high temperature is chemical reaction step, whereas that is the mass transport step at low temperature. Chlorination temperature has a weak influence on deposition rate and grain structure, the deposition rate and grain size of CVD Nb increased with the increase of the chlorine flow and hydrogen flow, the maximum deposition rate is [Formula: see text], thus, the optimum deposition temperature is 1200[Formula: see text]C, chlorination temperature is 350[Formula: see text]C, hydrogen flow is 400 ml, chlorine flow is 200 ml.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Long Giang Bach ◽  
Nam Giang Nguyen ◽  
Van Thi Thanh Ho

We have explored the effective approach to fabricate GZO/ZnO films that can make the pyramidal surface structures of GZO films for effective light scattering by employing a low temperature ZnO buffer layer prior to high temperature GZO film growth. The GZO thin films exhibit the typical preferred growth orientations along the (002) crystallographic direction at deposition temperature of 400°C and SEM showed that column-like granule structure with planar surface was formed. In contrast, GZO films with a pyramidal texture surface were successfully developed by the control of (110) preferred orientation. We found that the light diffuse transmittance of the film with a GZO (800 nm)/ZnO (766 nm) exhibited 13% increase at 420 nm wavelength due to the formed large grain size of the pyramidal texture surface. Thus, the obtained GZO films deposited over ZnO buffer layer have high potential for use as front TCO layers in Si-based thin film solar cells. These results could develop the potential way to fabricate TCO based ZnO thin film using MOCVD or sputtering techniques by depositing a low temperature ZnO layer to serve as a template for high temperature GZO film growth. The GZO films exhibited satisfactory optoelectric properties.


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