Integrated Two-Stage Processing of Microcrystalline Silicon Thin Films on SiO2 and Glass

1996 ◽  
Vol 429 ◽  
Author(s):  
D. Wolfe ◽  
F. Wang ◽  
G. Lucovsky
Keyword(s):  
Thin Films ◽  
Film Growth ◽  
Deposition Process ◽  
High Energy ◽  
Dark Conductivity ◽  
Microcrystalline Silicon ◽  
Two Stage ◽  
Temperature Plasma ◽  
Raman Scattering Spectroscopy ◽  
Glass Substrates

AbstractA novel two-stage low temperature plasma assisted deposition process, which separates interface formation from bulk film growth, was investigated for deposition of in-situ phosphorous doped microcrystalline silicon (μc-Si) thin films on SiO2 and glass substrates. We find that the bulk layer microstructure, as characterized by reflection high energy electron diffraction and Raman scattering spectroscopy, is the same whether or not a buffer layer is used. However, we find significant differences in the room temperature dark conductivity, and the dark conductivity activation energies.

Optical and Electronic Characterization of a-SiGe:H Thin Films Prepared by a Novel Hollow Cathode Deposition Technique

2004 ◽  
Vol 808 ◽  
Author(s):  
R. J. Soukup ◽  
N. J. Ianno ◽  
Scott A. Darveau ◽  
Christopher L. Exstrom
Keyword(s):  
Thin Films ◽  
Hollow Cathode ◽  
Secondary Ion Mass Spectrometry ◽  
Dark Conductivity ◽  
Cathode Plasma ◽  
Glass Substrates ◽  
Elemental Analyses ◽  
Silicon And Germanium ◽  
Secondary Ion

ABSTRACTUsing a novel hollow cathode plasma-jet reactive sputtering system in which an intense plasma, ignited in an Ar/H2 flow, is directed through silicon and germanium nozzles, a series of a-SiGe:H thin films have been prepared on silicon and glass substrates. These films have been optically characterized by infrared (IR) spectroscopy and spectroscopic ellipsometry (335-1000nm). Total hydrogen concentrations, as determined by FTIR, varied with deposition conditions and ranged from 2.5 × 1021 to 1.6 × 1022 atom cm−3 and correlated with secondary ion mass spectrometry (SIMS) elemental analyses to within 10%. Conductivity measurements in the dark and under simulated AM1 solar illumination have indicated that the films properties are very good. The light to dark conductivity ratio has consistently been greater than 1000 for films with band gaps down to 1.3 eV.

AlSb THIN FILMS PREPARED BY DC MAGNETRON SPUTTERING AND ANNEALING

2008 ◽  
Vol 22 (14) ◽  
pp. 2275-2283 ◽  
Author(s):  
WEIDONG CHEN ◽  
LIANGHUAN FENG ◽  
ZHI LEI ◽  
JINGQUAN ZHANG ◽  
FEFE YAO ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
High Efficiency ◽  
Dark Conductivity ◽  
Aluminum Antimonide ◽  
Dc Magnetron Sputtering ◽  
Glass Substrates ◽  
Average Grain Size ◽  
P Type ◽  
20 Nm

Aluminum antimonide (AlSb) is thought to be a potential material for high efficiency solar cells. In this paper, AlSb thin films have been fabricated by DC magnetron sputtering on glass substrates. The sputtering target consists of aluminum and antimony, and the area ratio of Al to Sb is 7:3, which is derived from research into the relationship between the deposition rates of both the metals and sputtering power. XRD and AFM measurements show that the as-deposited films are amorphous, but become polycrystalline with an average grain size of about 20 nm after annealing in an argon atmosphere. From optical absorption measurements of annealed AlSb films, a band gap of 1.56 eV has been demonstrated. Hall measurements show that the films are p-type semiconductors. The temperature dependence of dark conductivity tested in vacuum displays a linear lnσ to 1/T curve, which indicates a conductivity activation energy of around 0.61 eV.

Characterization of Grain Boundary Geometry in the TEM, Exemplified in Si Thin Films

2012 ◽  
Vol 186 ◽  
pp. 7-12 ◽  
Author(s):  
János L. Lábár ◽  
Ákos K. Kiss ◽  
Silke Christiansen ◽  
Fritz Falk
Keyword(s):  
Thin Films ◽  
Degrees Of Freedom ◽  
Sample Surface ◽  
High Energy ◽  
High Energy Density ◽  
Glass Substrates ◽  
Low Dimensional ◽  
Si Films ◽  
Alternative Routes

A method is presented here for complete geometrical characterization of grain boundaries, based on measurement of thin films in the TEM. First, the three parameters, characterizing the misorientation of the two neighboring grains are determined from convergent beam electron diffraction (CBED). Next, the last two (of the total five macroscopic degrees of freedom) parameters are determined from bright field (BF) images to describe the orientation of the boundary plane between them. Ambiguity in the tilt direction of the plane is resolved from BF images recorded at two distinct goniometer settings. Application of the method is demonstrated in Silicon thin films. GB-plane distribution in a thin film is not necessarily identical to the distribution of similar planes in bulk materials. It was observed in low dimensional fcc metals (wires or thin films) that energy minimization of GBs can follow two (mainly alternative) routes. Either low energy planes (like {111}) are formed in 3 boundaries, or alternatively, it is observed that the GB plane has a general index (and high energy density) but it ends at both free surfaces of the sample, resulting in a GB, almost normal to the sample surface, minimizing the total area of the GB. We observed that this later type of planes is mainly characteristic of non-3 boundaries in thin Si films, crystallized from melt on glass substrates (separated by a thin SiN barrier layer). This observation is important for the expected recombination properties of the multicrystalline Si (m-Si) in planned solar cell (SC) applications.

Effects of HWCVD-deposited Seed Layers on Hydrogenated Microcrystalline Silicon Films on Glass Substrates

2006 ◽  
Vol 910 ◽  
Author(s):  
Michael Musashi Adachi ◽  
Wing Fai Lydia Tse ◽  
Garnet Cluff ◽  
Karen L. Kavanagh ◽  
Karim S. Karim
Keyword(s):  
Seed Layer ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Microcrystalline Silicon ◽  
Crystalline Fraction ◽  
Glass Substrates ◽  
Photo Conductivity ◽  
Crystalline Nature ◽  
Deposited Films ◽  
Silane Concentration

AbstractMicrocrystalline silicon was deposited by hot-wire chemical vapor deposition (HWCVD) using a graphite filament with and without a thin 50 nm microcrystalline silicon seed layer. Increasing silane concentration diluted in H2 led to a decrease in crystalline fraction as well in a decrease in dark conductivity and photo-conductivity. In addition, films deposited with a seed layer were found to have higher dark conductivity and photo-conductivity than those without a seed layer but deposited at slower growth rates. However, Raman spectroscopy showed that use of a seed layer resulted in only a small increase in crystalline fraction at the surface of the films which had thicknesses between 250-400nm. TEM measurements confirmed the crystalline nature of deposited films showing average grain sizes of 25 nm.

Effect of Different Radios of Two Complexes on the Structural and Optical Properties of ZnS Thin Films

2014 ◽  
Vol 986-987 ◽  
pp. 47-50
Author(s):  
Jin Shang ◽  
Huan Ke ◽  
Shu Wang Duo ◽  
Ting Zhi Liu ◽  
Hao Zhang
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Visible Region ◽  
Deposition Process ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Structural And Optical Properties ◽  
Glass Substrates ◽  
Direct Band ◽  
Cbd Method

ZnS thin films were deposited at three different radios of V(NH3·H2O)/V(N2H4) on glass substrates by chemical bath deposition (CBD) method without stirring the deposition bath during the deposition process. The structural and optical properties were analyzed by X-ray diffraction (XRD) and UV-VIS spectrophotometer. The results showed that ZnS thin film deposited at the radio of V(NH3·H2O)/V(N2H4)=15:15 is higher than that of the other two different solutions. With the radio of V(NH3·H2O)/V(N2H4) decreasing from 15:5 to 15:15, homogenous precipitation of Zn (OH)2easily forms in the bath, but ZnS precipitation first become suppressed and then easily forms in solution. It means that the concentration of OH-ion increases with the volume of N2H4increasing, which accelerates the formation of Zn (OH)2. However, when the volume of N2H4increases to 15mL, relatively high concentration of OH-ion not only accelerates the formation of Zn (OH)2, but also be used to the hydrolysis of thiourea. The average transmissions of all the ZnS films from three different solutions (V(NH3·H2O)/V(N2H4)=15:5, 15:10 and 15:15) are greater than 90% for wavelength values in visible region. The direct band gaps range from 3.80 to 4.0eV. The ZnS film deposited for 2.5h with the radio of V(NH3·H2O)/V(N2H4)=15:15 has the cubic structure only after single deposition.

Absorber Films of Antimony Chalcogenides via Chemical Deposition for Photovoltaic Application

2004 ◽  
Vol 836 ◽  
Author(s):  
M. T. S. Nair ◽  
Y. Rodríguez-Lazcano ◽  
Y. Peña ◽  
S. Messina ◽  
J. Campos ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Optical Band Gap ◽  
Chemical Deposition ◽  
Dark Conductivity ◽  
Glass Substrates ◽  
Photovoltaic Application ◽  
Sodium Selenosulfate ◽  
P Type ◽  
Antimony Chalcogenides

ABSTRACTAntimony sulfide thin films (300 nm) have been deposited on glass substrates at 1–10°C from chemical bath. When heated these become crystalline and photoconductive with optical band gap (direct) of 1.7 eV. Thin films formed from chemical baths containing SbCl3 and sodium selenosulfate are of mixed phase Sb2O3/Sb2Se3, which when heated in the presence of Se-vapor converts to single phase Sb2Se3 film with optical band gap of 1.1 eV. Such films possess dark conductivity of 10-8 ohm-1cm-1 and show photosensitivity of two orders. Reaction of Sb2S3-CuS in nitrogen at 400°C produces crystalline, photoconductive p-type CuSbS2 with optical band gap (direct) of 1.5 eV. By controlling the deposition and heating condition, (i)Sb2S3-(p)CuSbS2 layer is formed, which is utilized in a photovoltaic structure, (n)CdS:In-(i)Sb2S3-(p)CuSbS2, with a Voc of 345 mV and Jsc 0.18 mA/cm2 under 1 kW m-2 tungsten halogen illumination. In the case of a structure, CdS:Cl-Sb2S3-Cu2-xSe, Voc of 350 mV and Jsc of 0.5 mA/cm2 are observed.

scholarly journals Preparation and Characterization of NbxOy Thin Films: A Review

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1246
Author(s):  
Nwanna Charles Emeka ◽  
Patrick Ehi Imoisili ◽  
Tien-Chien Jen
Keyword(s):  
Thin Films ◽  
Film Growth ◽  
Deposition Process ◽  
Optical Systems ◽  
Electrochromic Devices ◽  
Comprehensive Properties ◽  
Direct Band ◽  
Film Characteristics ◽  
The Impact

Niobium oxides (NbO, NbO2, Nb2O5), being a versatile material has achieved tremendous popularity to be used in a number of applications because of its outstanding electrical, mechanical, chemical, and magnetic properties. NbxOy films possess a direct band gap within the ranges of 3.2–4.0 eV, with these films having utility in different applications which include; optical systems, stainless steel, ceramics, solar cells, electrochromic devices, capacitor dielectrics, catalysts, sensors, and architectural requirements. With the purpose of fulfilling the requirements of a vast variety of the named applications, thin films having comprehensive properties span described by film composition, morphology, structural properties, and thickness are needed. The theory, alongside the research status of the different fabrication techniques of NbxOy thin films are reported in this work. The impact of fabrication procedures on the thin film characteristics which include; film thickness, surface quality, optical properties, interface properties, film growth, and crystal phase is explored with emphases on the distinct deposition process applied, are also described and discussed.

scholarly journals Controlling the flux of reactive species: a case study on thin film deposition in an aniline/argon plasma

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
D. Sciacqua ◽  
C. Pattyn ◽  
A. Jagodar ◽  
E. von Wahl ◽  
T. Lecas ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Growth ◽  
Argon Plasma ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Film Deposition ◽  
Capacitively Coupled ◽  
Low Temperature Plasmas ◽  
Free Films

Abstract The plasma based synthesis of thin films is frequently used to deposit ultra-thin and pinhole-free films on a wide class of different substrates. However, the synthesis of thin films by means of low temperature plasmas is rather complex due to the great number of different species (neutrals, radicals, ions) that are potentially involved in the deposition process. This contribution deals with polymerization processes in a capacitively coupled discharge operated in a mixture of argon and aniline where the latter is a monomer, which is used for the production of plasma-polymerized polyaniline, a material belonging to the class of conductive polymers. This work will present a particular experimental approach that allows to (partially) distinguish the contribution of different species to the film growth and thus to control to a certain extent the properties of the resulting material. The control of the species flux emerging from the plasma and contributing to the film growth also sheds new light on the deposition process, in particular with respect to the role of the ion component. The analysis of the produced films has been performed by means of Fourier Transform Infrared spectroscopy (FTIR) and Near Edge X-ray Absorption Fine Structure spectroscopy (NEXAFS).

Oxygen Pressure Dependence of Morphology of Morphology of La2-xSrxCuO4 Ultra-Thin Films

1997 ◽  
Vol 11 (21n22) ◽  
pp. 981-987
Author(s):  
H. Q. Yin ◽  
T. Arakawa ◽  
Y. Kaneda ◽  
T. Yoshikawa ◽  
N. Haneji ◽  
...  
Keyword(s):  
Thin Films ◽  
Pressure Dependence ◽  
Film Growth ◽  
Ambient Pressure ◽  
High Energy ◽  
Layer Growth ◽  
Growth Mode ◽  
Layer By Layer ◽  
Island Growth ◽  
Experimental Conditions

La 2-x Sr x CuO 4 ultra-thin films with thickness 200 Å were fabricated by pulsed laser deposition method in oxygen ( O 2) atmosphere. The morphology of deposited films was investigated by reflection high energy electron diffraction (RHEED), atomic force microscopy (AFM) and scanning electronic microscopy (SEM). The strong oxygen ambient pressure dependence of film morphology was observed. In high oxygen ambient pressure, the film growth is dominated by island growth mode. The results imply that the experimental conditions of oxygen ambient pressure and substrate temperature are critical for the layer-by-layer growth mode.

A Low Temperature Plasma-Assisted Deposition Process for Microcrystalline Thin Film Transistors, TFTS

1994 ◽  
Vol 336 ◽  
Author(s):  
S.S. He ◽  
G. Lucovsky
Keyword(s):  
Low Temperature ◽  
Deposition Process ◽  
Dark Conductivity ◽  
Low Temperature Plasma ◽  
Conductivity Activation Energy ◽  
Temperature Plasma ◽  
Threshold Voltages ◽  
Gate Structure ◽  
Saturation Region ◽  
Effective Channel

ABSTRACTThe drive-current of low-temperature (∼300°C) deposited TFTs has been increased by replacing the a-Si:H channel, and source and drain materials with μc-Si. Lightly B2H6 doped, near-intrinsic μc-Si has been used as the channel layer of the TFTs, and n+ μc-Si was used for the source and drain contacts. The compensation of intrinsic defects in the undoped μc-Si by boron doping increases the dark conductivity activation energy from -0.35 eV to 0.8 eV. TFTs were fabricated in a bottom gate structure, and required an H2 plasma treatment to produce devices with effective channel mobilities of -6.8 cm2/V-s and threshold voltages of -3.7 V in the saturation region.

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