A Comparative Study of Hydrogenated Amorphous Silicon Films Prepared by RF Sputtering in He/H2, Ar/H2 and Xe/H2 Mixtures

1986 ◽  
Vol 70 ◽  
Author(s):  
Mark L. Albers ◽  
H. R. Shanks ◽  
J. Shinar
Keyword(s):  
Comparative Study ◽  
Energy Gap ◽  
Rf Sputtering ◽  
Dangling Bond ◽  
Rf Power ◽  
Optical Energy Gap ◽  
Sputtered Films ◽  
Optical Gap ◽  
Hydrogenated Amorphous ◽  
Spin Densities

ABSTRACTPreliminary results of a comparative study of some optical and ESR properties of aSi:H films prepared by rf sputtering on a cold substrate in 10 mtorr of either He, Ar, or Xe and 0.5 mtorr H2 are presented. In all cases the concentration of Si-H and Si-H2 bonds, the optical gap and the dangling bond spin density all generally increase as the rf power is decreased from 3.3 to 0.27 W/cm2. However, whereas the optical energy gap of He/H2 sputtered films ranges from 1.26 eV to 2.13 eV, the gap of Ar/H2 and Xe/H2 films sputtered under these conditions only changes from 1.54 to 1.94 and 1.41 to 1.71 eV, respectively. The dangling bond spin densities are lowest (~1017 cm-3) in the Ar/H2 sputtered films at high rf power and highest (~5x1018 cm-3) in Xe/H2 sputtered films at low power.

Morphological characteristics and optical properties of hydrogenated amorphous silicon thin films

2016 ◽  
Vol 30 (12) ◽  
pp. 1650140
Author(s):  
Haihua Tang ◽  
Shuang Liu ◽  
Xiang Zhou ◽  
Yunfei Liu ◽  
Dejun Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Power Density ◽  
Energy Gap ◽  
Hydrogenated Amorphous Silicon ◽  
Morphological Characteristics ◽  
Rf Power ◽  
Optical Energy Gap ◽  
Reaction Pressure ◽  
Hydrogenated Amorphous

Hydrogenated amorphous silicon (a-Si:H) thin films were prepared by radio frequency (RF) plasma enhanced chemical vapor deposition (RF-PECVD) technique with silane (SiH[Formula: see text] as reactive gas. The influence of process parameters on the morphological characteristics and optical properties of a-Si:H thin films were systematically investigated. When the RF power density was taken as the only variable, it firstly improves the smoothness of the surface with increasing the RF power density below the value of 0.17 W/cm2, and then exhibits an obvious degradation at further power density. The refractive index, extinction coefficient, optical energy gap initially increase and reach a maximum at 0.17 W/cm2, followed by a significant decrease with further RF power density. When the RF power density was taken as the only variable, the surface of a-Si:H thin films become smoother by increasing the reaction pressure in the investigated range (from 50 Pa to 140 Pa), and the refractive index, extinction coefficient, optical energy gap increase with increasing of reaction pressure. The effect of RF power density and the reaction pressure on the morphological characteristics and optical properties of a-Si:H thin films was obtained, contributing to the further studies of the performance and applications of a-Si:H thin films.

Structural Properties of a-Ge1-xCx:H Alloys Prepared by the RF Sputtering Technique

1997 ◽  
Vol 467 ◽  
Author(s):  
F. C. Marques ◽  
J. Vilcarromero ◽  
F. L. Freire
Keyword(s):  
Carbon Content ◽  
Rf Sputtering ◽  
Low Carbon ◽  
Infrared Transmission ◽  
Absorption Bands ◽  
Optical Gap ◽  
High Carbon Concentration ◽  
Bending Modes ◽  
Hydrogenated Amorphous ◽  
Hydrogenated Amorphous Germanium

ABSTRACTStructural and mechanical properties of hydrogenated amorphous germanium carbon (a-Ge1-xCx:H) alloys are presented. The films were prepared by the rf-co-sputtering technique using a graphite/germanium composed target. The carbon and germanium relative concentrations were determined by RBS, and the total hydrogen concentration by ERDA measurements. An increase in the optical gap was measured for low carbon content (0 < × < 0.15). For higher values of x the optical gap is almost constant. Infrared transmission absorption spectra show several absorption bands related to Ge-C stretching, C-Hn (n = 1,2,3) and Ge-H stretching and bending modes. The mechanical internal stress was strongly affected by the incorporation of carbon. The trends of the optical gap, refractive index, infrared absorption and mechanical stress as a function of the carbon content suggest that the high carbon concentration alloys have polymeric and/or graphite-like contribution in their structure.

Novel Carbon Source (1,3-Disilabutane) for the Deposition of P-Type a-SiC

2002 ◽  
Vol 715 ◽  
Author(s):  
Shuhei Yagi ◽  
Takashi Okabayashi ◽  
Katsuya Abe ◽  
Akira Yamada ◽  
Makoto Konagai
Keyword(s):  
Carbon Source ◽  
Vapor Deposition ◽  
Energy Gap ◽  
Hydrogenated Amorphous Silicon ◽  
Type A ◽  
Optical Energy Gap ◽  
P Type ◽  
Photochemical Vapor Deposition ◽  
Hydrogenated Amorphous ◽  
Sic Films

AbstractWe proposed a new carbon source, 1,3-disilabutane (H3Si-CH2-SiH2-CH3:1,3-DSB), to grow hydrogenated amorphous silicon carbide (a-SiC:H) films by mercury-sensitized photochemical vapor deposition (photo-CVD). We described preliminary results of undoped and p-type a-SiC films deposited using 1,3-DSB. It was found that the optical energy gap of the films was changed even at very small 1,3-DSB/silane ratios of few percents. P-type doping was carried out by using diborane and we obtained the films with a darkconductivity of 1.3x10-4 S/cm at the optical bandgap of 2.1 eV. In addition, we applied this material for a p-layer of a p-i-n type a-Si based solar cell and we have achieved relatively high conversion efficiency of 9.55%.

Preparation of Rutile and Anatase Phases Titanium Oxide Film by RF Sputtering

2008 ◽  
Vol 8 (5) ◽  
pp. 2659-2664 ◽  
Author(s):  
Hong-Hsin Huang ◽  
Chia-Chen Huang ◽  
Ping-Chih Huang ◽  
Cheng-Fu Yang ◽  
Ching-Yun Hsu
Keyword(s):  
Titanium Oxide ◽  
Deposition Temperature ◽  
Energy Gap ◽  
Anatase Phase ◽  
Oxide Films ◽  
Rf Sputtering ◽  
Rf Magnetron Sputtering ◽  
Rutile Phase ◽  
Rf Power ◽  
Titanium Oxide Films

Titanium oxide films were prepared by RF magnetron sputtering onto glass substrates. The effects of RF power and deposition temperature on crystalline structure, morphology and energy gap were investigated, which were analyzed by X-ray diffraction, SEM and UV-Vis spectrometer, respectively. Results show that rutile phase is the favored structure during deposition. Applying RF power in the range of 50–250 W, the amorphous, rutile, and both rutile and anatase phases TiO2 films were obtained in sequence, while the content of anatase is similar in the range of 34–37% although the RF power increases. Increasing the deposition temperature, the anatase phase coexists in the rutile phase in the range of 100–200 °C, and the content of anatase increases from 20 to 41% with the deposition temperature. In addition, according to the morphology observation, the granulous surface is found in rutile phase while facetted surface in anatase phase when titanium oxide films deposited at various RF powers and substrate temperatures. The band gap energy of titanium oxide evaluated from (αhν)1/2 versus energy plots show that the energy gap decreases with RF power increasing.

Properties of Binary Si:H Materials Prepared by Hydrogen Plasma Sputtering

1989 ◽  
Vol 164 ◽  
Author(s):  
Shoji Furukawa ◽  
Tatsuro Miyasato
Keyword(s):  
Substrate Temperature ◽  
Room Temperature ◽  
Hydrogen Plasma ◽  
Rf Sputtering ◽  
Hydrogen Atmosphere ◽  
Pure Hydrogen ◽  
Rf Power ◽  
Optical Gap ◽  
Plasma Sputtering ◽  
X Ray Scattering

AbstractBinary Si:H materials are prepared by means of the rf sputtering technique in pure hydrogen atmosphere on low temperature (about 100 K) and room temperature substrates. The physical properties of the obtained materials are very much affected by the rf power and substrate temperature during the deposition. The material prepared at a low substrate temperature with a low rf power has a wide optical gap, and shows a visible photoluminescence at room temperature. On the other hand, the material prepared at room temperature with a high rf power contains many Si microcrystals, whose diameters are relatively large, and its optical gap becomes very small. The latter condition causes the dependence of the crystalline direction of the material film on the substrate crystal even at the room temperature. An rf power-modulated multi-layered structure (superlattice) is also proposed, and an apparent diffraction peak can be observed in the low-angle X-ray scattering measurement.

Thermal and Mechanical Properties of Diamond-Like a-C:H Films

1992 ◽  
Vol 270 ◽  
Author(s):  
G. Amato ◽  
G. Benedetto ◽  
L. Boarino ◽  
F. Demichelis ◽  
C. F. Pirri ◽  
...  
Keyword(s):  
Amorphous Carbon ◽  
Room Temperature ◽  
Rf Sputtering ◽  
Carbon Films ◽  
Complete Characterization ◽  
Thermal And Mechanical Properties ◽  
Amorphous Carbon Films ◽  
Optical Gap ◽  
Hydrogenated Amorphous

ABSTRACTDiamond-like amorphous carbon and hydrogenated amorphous carbon films (DLC) prepared by rf sputtering have been characterized by means of measurements of optical gap, hardness and Young's modulus. Preliminary results of the application of the photothermal displacement technique (PTD) are also reported, confirming that this method can in principle be applied for a more complete characterization of DLC films at room temperature and low temperatures.

The Effects of Deposition Pressure on the Optical and Structural Properties of d.c. PECVD Hydrogenated Amorphous Carbon Films

2006 ◽  
Vol 517 ◽  
pp. 81-84
Author(s):  
Rozidawati Awang ◽  
Goh Boon Tong ◽  
Siti Meriam Ab. Gani ◽  
Richard Ritikos ◽  
Saadah Abdul Rahman
Keyword(s):  
Thin Films ◽  
Deposition Rate ◽  
Amorphous Carbon ◽  
Energy Gap ◽  
Chemical Vapour ◽  
Carbon Films ◽  
Deposition Pressure ◽  
Optical Energy Gap ◽  
Hydrogenated Amorphous Carbon ◽  
Hydrogenated Amorphous

A direct-current plasma enhanced chemical vapour deposition (PECVD) system was designed and built in-house for the deposition of hydrogenated amorphous carbon(a-C:H) thin films. In this work, a-C:H thin films prepared using this system at different deposition pressures were studied. The influence of deposition pressure on the deposition rate, energy gap, bonded hydrogen content and structure of the film has been investigated. The characterization techniques were determined from optical transmission spectroscopy, Fourier transform infrared spectroscopy and Xray diffraction measurements. The results demonstrated that the deposition pressure had strong influence on the deposition rate, optical energy gap and the bonded H content in the film. Evidence of crystallinity was observed in films prepared at low deposition pressure.

Deposition and Characterization of Carbon Films Produced by Nitrogen/Argon Mixture RF Sputtering

1989 ◽  
Vol 162 ◽  
Author(s):  
C. J. Tomg ◽  
T. Yeh ◽  
J. M. Sivertsen ◽  
J. H. Judy
Keyword(s):  
Partial Pressure ◽  
Energy Gap ◽  
Rf Sputtering ◽  
Argon Plasma ◽  
Nitrogen Plasma ◽  
Carbon Films ◽  
Nitrogen Partial Pressure ◽  
Optical Energy Gap ◽  
Thin Carbon ◽  
Argon Mixture

ABSTRACTThin carbon films were prepared by RF diode sputtering of a graphite target in a mixed nitrogen/argon plasma. A series of carbon films were deposited as a function of nitrogen partial pressure. We have observed a systematic variation of the properties of the carbon films with an increase of the nitrogen partial pressure. AES, XPS and energy gap studies showed that nitrogen will enhance the diamond sp3 bonding. Consistent with this the optical energy gap of our C:N films shows an increase from 1.1 eV to 1.4 eV using, respectively, 25 to 100 % nitrogen plasma. The mechanical properties also are shown to be enhanced for certain applications.

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