Optimization of the Deposition Conditions for High-Gap a-Si,Ge:H,F Alloys

1992 ◽  
Vol 258 ◽  
Author(s):  
P.A. Morin ◽  
N.W. Wang ◽  
S. Wagner
Keyword(s):  
Figure Of Merit ◽  
Defect Density ◽  
Initial Defect ◽  
Optical Gap ◽  
Deposition Parameters ◽  
Defect Densities ◽  
Deposition Conditions

ABSTRACTWe report the deposition parameters for optimized a-Si,Ge:H,F alloys in the range of optical (Taue) gap 1.5 leV to 1.62eV. These deposition parameters were optimized using the saturated defect density as a figure of merit. We report initial defect densities at or below 2.5×1016 cm-3, saturated defect densities below 9×1016 cm-3, photoconductivities (at G = 1021 cm-3s-1) between 8.7×10-6 Scm-1 and 7×10-5 Scm-land photosensitivities between 104 and 105 for alloys in this range of optical gap.

The Farthest Reaches of a-Si,Ge:H,F Parameter Space… Where no One Has Gone Before

1992 ◽  
Vol 258 ◽  
Author(s):  
P.A. Morin ◽  
N.W. Wang ◽  
S. Wagner
Keyword(s):  
Growth Rate ◽  
Parameter Space ◽  
Growth Rates ◽  
Film Growth ◽  
Defect Density ◽  
Initial Defect ◽  
Figures Of Merit ◽  
Rate Dependent ◽  
Deposition Parameters ◽  
Defect Densities

ABSTRACTWe report the deposition parameters for optimized a-Si,Ge:H,F alloys in the range of optical (Taue) gap of 1.22eV to 1.65eV. These deposition parameters were optimized using the photosensitivity and initial defect density as figures of merit. We observe two distinct regimes of film growth rate, dependent on the choice of source gases. Growth from fluoride source gases results in a growth rate of less than 0.6 Ås--1. Growth from a mixture of fluorides and silane gives a range of growth rates from 2 Ås-l to 5.5Ås1. Alloys in both regimes display the low defect densities and the high photosensitivities required for devices.

Improved Light Soaking Stability of R.F. Sputter Deposited Amorphous Silicon

1991 ◽  
Vol 219 ◽  
Author(s):  
A. Wynveen ◽  
J. Fan ◽  
J. Kakalios ◽  
J. Shinar
Keyword(s):  
Amorphous Silicon ◽  
Hydrogen Content ◽  
Defect Density ◽  
Hydrogenated Amorphous Silicon ◽  
Dark Conductivity ◽  
Initial Defect ◽  
Optical Gap ◽  
Sputter Deposited ◽  
Staebler Wronski Effect ◽  
Hydrogenated Amorphous

ABSTRACTStudies of r.f. sputter deposited hydrogenated amorphous silicon (a-Si:H) find that the light induced decrease in the dark conductivity and photoconductivity (the Staebler-Wronski effect) is reduced when the r.f. power used during deposition is increased. The slower Staebler-Wronski effect is not due to an increase in the initial defect density in the high r.f. power samples, but may result from either the lower hydrogen content or the smaller optical gap found in these films.

The Electronic Properties of a-Si:H Deposited With Hydrogen or Helium Dilution

1996 ◽  
Vol 420 ◽  
Author(s):  
F. Zhong ◽  
W. S. Hong ◽  
V. Perez-Mendez ◽  
C. C. Chen ◽  
J. D. Cohen
Keyword(s):  
Defect Density ◽  
Schottky Diodes ◽  
Growth Conditions ◽  
Drive Level ◽  
Standard Samples ◽  
Level Densities ◽  
Helium Dilution ◽  
Neutral Defect ◽  
Defect Densities ◽  
Deposition Conditions

AbstractWe have applied the Drive-Level Capacitance Profiling (DLCP) method to n-i-p a-Si:H diodes to characterize the mid-gap defect densities in the i layer. Our results show that there are no significant changes in the drive-level densities, Ndl, in n-i-p diodes and p+-i-m as well as n-i-m Schottky diodes, which indicates that DLCP can directly provide reliable energy distribution and spatial distribution of the mid-gap defects in the n-i-p device. We have found that the ratio of Ndl to ND*, the ionized defect density determined by hole onset measurement, is changed with the deposition conditions; it is 3 for standard samples, 2 for helium diluted samples and 6 for hydrogen diluted samples. These results indicate that there may be different defect distributions in these materials, which suggest the ratio of charged (D-) density to the neutral defect (D0) density may be altered when growth conditions are varied.

Optoelectronic Properties of Plasma CVD a-Si:H Modified by Filament-Generated Atomic H

1992 ◽  
Vol 258 ◽  
Author(s):  
Y.M. Li ◽  
I. An ◽  
M. Gunes ◽  
R.M. Dawson ◽  
R.W. Collins ◽  
...  
Keyword(s):  
Film Thickness ◽  
Real Time ◽  
Chemical Potential ◽  
Defect Density ◽  
Plasma Deposition ◽  
Plasma Cvd ◽  
Near Surface ◽  
Optical Gap ◽  
New Material ◽  
Control Samples

ABSTRACTWe have studied a-Si:H prepared by alternating plasma deposition with atomic H treatments performed with a heated W filament. Real time spectroscopie ellipsometry provides the evolution of film thickness, optical gap, and a measure of the fraction of Si-Si bonds broken in the near-surface (200 Å) during H-exposure of single films. This information guided us to the desired parameters for the H-treatments. Here, we concentrate on a weak hydrogenation regime characterized by minimal etching, a higher H content by 2 at.%, and a larger optical gap by 0.02 eV for the growth/hydrogenation structures in comparison to continuously deposited control samples. This new material has shown an improvement in the defect density in the light-soaked state in comparison to the control samples. This may result from stabilization of the Si structure due to an increase in the H chemical potential in the a-Si:H.

Growth and Characterization of 2″ 6H-Silicon Carbide

1999 ◽  
Vol 572 ◽  
Author(s):  
Erwin Schmitt ◽  
Robert Eckstein ◽  
Martin Kölbl ◽  
Amd-Dietrich Weber
Keyword(s):  
Silicon Carbide ◽  
Boundary Conditions ◽  
Growth Process ◽  
Defect Density ◽  
Crystal Quality ◽  
Process Conditions ◽  
Thermal Boundary Conditions ◽  
Sublimation Growth ◽  
Defect Densities

ABSTRACTFor the growth of 2″ 6H-SiC a sublimation growth process was developed. By different means of characterization crystal quality was evaluated. Higher defect densities, mainly in the periphery of the crystals were found to be correlated to unfavourable process conditions. Improvement of thermal boundary conditions lead to a decreased defect density and better homogeneity over the wafer area.

Investigation of the Defect Size and Density in Thin SiON Filmfor Organic Device Encapsulation

2016 ◽  
Vol 2016 (1) ◽  
pp. 000272-000276
Author(s):  
Kunmo Chu ◽  
Ki Deok Bae ◽  
Byong Gwon Song ◽  
Yong Young Park ◽  
Jaekwan Kim ◽  
...  
Keyword(s):  
Defect Density ◽  
Chemical Vapor ◽  
Defect Size ◽  
Intrinsic Defect ◽  
Ni Substrate ◽  
Defect Site ◽  
Defect Sites ◽  
Chemical Vapor Deposited ◽  
Density Values ◽  
Defect Densities

Abstract In this study, thin SiON was grown by plasma enhanced chemical vapor deposited (PECVD) method as a thin-film encapsulation (TFE) layer. For defect visualization, electroplating results in a Cu bump grown at each defect site in the SiON film where electrolytic solution establishes contact with the Ni substrate. It was inferred that the Cu bump density could be representative of the intrinsic defect densities for the SiON film. The defect density values were obtained by monitoring the Cu bumps grown at defect sites in the SiON films and then evaluating the number of densities of the Cu bumps for the corresponding defect densities.At the same time, by analyzing the cross section of the Cu bumps grown on SiON film, a linear relation between the Cu bump diameter and the defect size increase was obtained. We expect that this electroplating method allows for rapid visualization of defect distribution and quality evaluation of TFE layers.

Defect density in a metal-monolayer-metal cell

1980 ◽  
Vol 33 (8) ◽  
pp. 1713 ◽  
Author(s):  
IR Peterson
Keyword(s):  
Defect Density ◽  
High Surface ◽  
Langmuir Blodgett ◽  
Minimum Deformation ◽  
Defect Densities

Techniques for Langmuir-Blodgett monolayer deposition at high surface pressures and with minimum deformation have been studied by measurement of the resultant defect densities in a metal-monolayer-metal cell.

Polyvinylidene fluoride (PVDF) as a feedstock for material extrusion additive manufacturing

2020 ◽  
Vol 26 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Niknam Momenzadeh ◽  
Hadi Miyanaji ◽  
Daniel Allen Porter ◽  
Thomas Austin Berfield
Keyword(s):  
Additive Manufacturing ◽  
Polyvinylidene Fluoride ◽  
Mechanical Response ◽  
Dimensional Accuracy ◽  
Piezoelectric Response ◽  
Content Type ◽  
Material Extrusion ◽  
Deposition Parameters ◽  
The Individual ◽  
Deposition Conditions

Purpose This study aims to investigate the material extrusion additive manufacturing (MEAM) deposition parameters for creating viable 3-D printed polyvinylidene fluoride (PVDF) structures with a balanced mix of mechanical and electrical properties. Design/methodology/approach Different combinations of deposition conditions are tested, and the influence of these parameters on the final dimensional accuracy, semi-crystalline phase microstructure and effective mechanical strength of MEAM homopolymer PVDF printed parts is experimentally assessed. Considering printed part integrity, appearance, print time and dimensional accuracy, MEAM parameters for PVDF are suggested. Findings A range of viable printing parameters for MEAM fabricated PVDF Kynar 740 objects of different heights and in-plane length dimensions was determined. For PVDF structures printed under the suggested conditions, the mechanical response and the microstructure development related to Piezoelectric response are reported. Originality/value This research first reports on a range of parameters that have been confirmed to facilitate effective MEAM printing of 3-D PVDF objects, presents effects of the individual parameters and gives the mechanical and microstructure properties of PVDF structures fabricated under the suggested deposition conditions.

Saturation behavior of the Light-Induced Defect Density in Hydrogenated Amorphous Silicon

1990 ◽  
Vol 192 ◽  
Author(s):  
H. R. Park ◽  
J. Z. Liu ◽  
P. Roca i Cabarrocas ◽  
A. Maruyama ◽  
M. Isomura ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Room Temperature ◽  
Urbach Energy ◽  
Defect Density ◽  
Generation Rate ◽  
Carrier Generation ◽  
Defect Generation ◽  
Ion Laser ◽  
Hydrogenated Amorphous ◽  
Defect Densities

ABSTRACTUsing a Kr ion laser (λ = 647.1 nm) to produce a carrier generation rate G of 3 × 1020 cm−3s−1, we have saturated the light-induced defect generation in hydrogenated (and fluorinated) amorphous silicon (a-Si:H(F)), within a few hours near room temperature. While the defect generation rate scales roughly with 1/G2, the saturation defect densities Ns,sat are essentially independent of G. The saturation is not due to thermal annealing. We have further measured Ns,sat m 37 a-Si:H(F) films grown in six different reactors under different conditions. The results show that Ns,sat lies between 5 × 1016 and 2 × 1017 cm−3, that Ns,sat drops with decreasing optical gap and hydrogen content, and that Ns,sat is not correlated with the initial defect density or with the Urbach energy.

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