Single Wafer Amorphous Silicon Process Evaluation

1997 ◽  
Vol 467 ◽  
Author(s):  
David O'Meara ◽  
Chow Ling Chang ◽  
Roc Blumenthal ◽  
Rama I. Hegde ◽  
Lata Prabhu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Amorphous Silicon ◽  
Deposition Rate ◽  
Cross Sections ◽  
Growth Conditions ◽  
Degree Of Crystallinity ◽  
Deposition Parameters ◽  
Before And After ◽  
Production Requirement

ABSTRACTSingle wafer amorphous silicon deposition was characterized through process modeling and film characterization for application in semiconductor production. DOE methodology was used to determine the main deposition parameters, and the responses were limited to device production requirement properties of surface roughness, deposition rate and degree of crystallinity of the as-deposited film. The data trends and models show that deposition temperature and silane flow are the main factors. Increasing either or both factor increases the deposition rate and the surface roughness. The surface morphology, evaluated by AFM, SEM and TEM, was found to be rougher at extreme growth conditions than the poly crystalline film formed after anneal. The as-deposited surface morphology was not a result of pre-anneal crystal formations as determined by TEM cross sections of samples before and after anneal. Lack of crystalinity is important for impurity diffusion considerations. Device application of the single wafer a-Si process will be a compromise between growth rate (and associated throughput) and surface roughness that can be tolerated.

Effect of Growth Conditions on Electronic and Structural Properties of GZO Films Grown by Plasma-enhanced Molecular Beam Epitaxy on p-GaN(0001)/Sapphire Templates

2011 ◽  
Vol 1315 ◽  
Author(s):  
H.Y. Liu ◽  
V. Avrutin ◽  
N. Izyumskaya ◽  
M.A. Reshchikov ◽  
S. Wolgast ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Molecular Beam Epitaxy ◽  
Surface Morphology ◽  
Molecular Beam ◽  
Three Dimensional ◽  
Optical Transmittance ◽  
Growth Conditions ◽  
Visible Spectral Range ◽  
Light Emitting ◽  
Surface Morphologies

Abstract:We report on a strong effect of p-GaN surface morphology on the growth mode and surface roughness of ZnO:Ga films grown by plasma-assisted molecular-beam epitaxy on p-GaN/c-sapphire templates. A range of ZnO:Ga surface morphologies varying from rough surfaces with well defined three-dimensional islands, capable to enhance light extraction in light-emitting diodes, to rather smooth surfaces with a surface roughness of ~ 2 nm suitable for vertical-cavity lasers can be achieved by controlling the surface morphologies of p-GaN. Optical transmittance measurements revealed high transparency exceeding 90% in the visible spectral range for ZnO:Ga with both types of surface morphology.

scholarly journals Archaeological chert artifacts from Atapuerca sites (Burgos, Spain): Characterization, causes of decay and selection of compatible consolidating products

2020 ◽  
Author(s):  
Ainara Zornoza-Indart ◽  
Paula Lopez-Arce ◽  
Lucía López-Polín
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Acrylic Resin ◽  
Degree Of Crystallinity ◽  
Mountain Range ◽  
Optical Surface ◽  
Conservation Treatment ◽  
Peeling Test ◽  
Non Destructive ◽  
Selection Of

Chert tools from Galería and Gran Dolina Caves, located in the Sierra de Atapuerca site complex (Burgos, Spain), were characterized (macro-visual inspection, mineralogical phases, degree of crystallinity, soluble salts, surface morphology and optical surface roughness) and compared to chert samples collected from the surrounding Atapuerca mountain range. The chert tools were studied to determine their causes of decay and for selecting the most compatible consolidation treatments. It was found that samples solely containing quartz were not significantly altered and required little conservation treatment compared to those that contained quartz and moganite, which were more weathered and powdery, requiring consolidation. The efficacy of the consolidating products traditionally used by conservators (acrylic resin and ethyl silicate) to preserve these chert remains, together with novel nanoparticle-based products (SiO2 and a mixture of SiO2 and Ca(OH)2 nanoparticles) were assessed in this study. Changes produced by these consolidating products in the physical (surface morphology and cohesion) and aesthetic properties of the chert tools were evaluated using non-destructive techniques (peeling test, spectrophotometry and optical surface roughness), followed by destructive techniques, such as SEM and XRD.

scholarly journals Effect of laser deweighting on properties of ZL205A aluminum alloy

2021 ◽  
Vol 2137 (1) ◽  
pp. 012033
Author(s):  
Guang Li ◽  
Zhipeng Wei ◽  
Junlong Wang ◽  
Yangyang Zhang ◽  
Chen Wang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Aluminum Alloy ◽  
Surface Morphology ◽  
Pulse Laser ◽  
Process Parameters ◽  
Experimental Results ◽  
Matrix Properties ◽  
Before And After ◽  
The Matrix

Abstract In this paper, a nanosecond fiber pulse laser is used to carry out the experimental study on laser weight removal of ZL205A aluminum alloy gyro rotor. By optimizing the process parameters of laser weight removal, better surface morphology was obtained. The effects of surface roughness, metallographic structure and hardness of samples before and after laser deweighting were analyzed. The experimental results show that the laser weight removal does not affect the matrix properties of ZL205A aluminum alloy. The laser de-weight technology is suitable for the balance of ZL205A aluminum alloy gyro rotor.

The Relationship Between Hip Simulator Wear and Surface Morphology Characterized Using White Light Interferometry

1999 ◽  
Author(s):  
C. L. Muhlstein ◽  
S. M. Kurtz ◽  
C. Chui ◽  
M. Rising ◽  
A. A. Edidin
Keyword(s):  
Surface Roughness ◽  
Wear Rate ◽  
Surface Morphology ◽  
White Light ◽  
Polymeric Materials ◽  
Wear Testing ◽  
White Light Interferometry ◽  
Hip Simulator ◽  
Before And After ◽  
Statistical Relationships

Abstract A non-contact surface topography measurement system based on white light interferometry was used to quantify the surface morphology of the UHMWPE, PTFE, HDPE, and polyacetal liners before and after wear testing. We investigated the hypothesis that the wear rate of four polymeric materials in the hip simulator was related to quantitative metrics of the surface morphology (i.e., surface roughness). Nine common roughness parameters (PV, Ra, Rrms, Rsk, Rku, Rtm, Rz, R3z, and H) were evaluated in 28 acetabular liners. The surface morphology within a given material was reproducible from insert to insert. Statistical relationships were observed between the surface roughness of the acetabular liners and the volumetric wear rate (p < 1 × 10−6). However, the power law relationships accounted for less than 50% of the variability in the data, based on r2.

A New Type of Cylindrical a-Si:H X-Ray Detector

1996 ◽  
Vol 420 ◽  
Author(s):  
D. Link ◽  
H. Keppner ◽  
P. Chabloz ◽  
A. Shah ◽  
J.-F. Germond ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Deposition Rate ◽  
Successful Development ◽  
Detector Performance ◽  
X Ray ◽  
Deposition Parameters ◽  
New Type ◽  
Powder Formation

AbstractThe present paper describes a new type of cylindrical X-ray detector based on thick amorphous silicon diodes. The authors report on the successful development of these detectors that have diameters as small as 3mm. The effect of silane dilution in hydrogen on deposition rate, powder formation, layer adhesion and detector performance is discussed. A set of deposition parameters is presented, that allows a reasonable compromise between the mentioned effects. First prototypes of this type of dosimeter have been characterised with the radiation from a 60Co source in a hospital. The corresponding results and interpretation are given in this paper.

Surface Morphology of Thin Film Deposited on Rotating Substrate by EB-PVD

2007 ◽  
Vol 336-338 ◽  
pp. 2238-2241
Author(s):  
Ying Chun Shan ◽  
Xiao Dong He ◽  
Ming Wei Li ◽  
Yao Li
Keyword(s):  
Thin Film ◽  
Surface Roughness ◽  
Surface Morphology ◽  
Deposition Rate ◽  
Physical Vapor Deposition ◽  
Rotation Axis ◽  
Kinetic Monte Carlo ◽  
Incident Angle ◽  
Critical Value ◽  
Surface Collision

The thin film deposited by electron beam physical vapor deposition (EB-PVD) on rotating substrate was approached via a kinetic Monte Carlo (KMC) algorithm on a “surface” of tight-packed rows. The motivation is to study the surface morphology distribution of thin film along the substrate radial. Effective deposition rate model and effective incident angle model were established along the substrate radial. Two phenomena are incorporated in the KMC simulation: adatom-surface collision and adatom diffusion. The KMC simulations show that the surface roughness of thin film is small and the changing of surface roughness is small near the side of rotation axis, however, the surface roughness is big near the side of substrate edge, and the surface roughness increases quickly with the increasing of substrate radius when r>300 mm. The simulation results indicate that the effective incident angle is the main factor to cause the changing of surface roughness: the effective incident angle does not reach critical value and the deposition rate difference is small when the radius is less than 300 mm, so the surface roughness of thin film in the scope is small and its changing is small, but when r>300 mm, the effective incident angles increase sharply with radius increasing and all of them are above the critical value, which cause surface roughness of thin film to increase quickly. Experiments reveal that the KMC method can predict surface roughness distribution of thin film deposited by EB-PVD on rotating substrate.

Deposition Conditions for Large Area PECVD of Amorphous Silicon

1997 ◽  
Vol 467 ◽  
Author(s):  
J. Kuske ◽  
U. Stephan ◽  
W. Nowak ◽  
S. Röhlecke ◽  
A. Kottwitz
Keyword(s):  
Film Thickness ◽  
Amorphous Silicon ◽  
Deposition Rate ◽  
Excitation Frequency ◽  
Input Power ◽  
High Deposition Rate ◽  
Large Area ◽  
Deposition Parameters ◽  
Plate Size ◽  
Area Deposition

ABSTRACTThe production of amorphous silicon devices usually requires large area, high-deposition-rate plasma reactors. Non-uniformity of the film thickness at high power and deposition rate is found to be an important factor for large area deposition.Increasing the radio frequency from the conventional 13.56 MHz up to VHF has demonstrated advantages for the deposition of a-Si:H films, including higher deposition rates and lower particle generation. The use of VHF for large area deposition leads to the generation of standing waves and evanescent waveguide modes at the electrode surface and on the power feeding lines. Thereby increasing the non-uniformity of the film thickness. The uniformity of the film thickness for an excitation frequency strongly depends on the deposition parameters e.g. pressure, input power, silane flow and the value of load impedances. With increasing exciting frequencies the range of deposition parameters for obtaining uniform films narrows.Subsequently it is shown that for a large-area plasma-box reactor (500 × 600 mm2 plate size) with a double-sided RF electrode, the non-uniformity of the film decreases due to a homoge-neization of the electrode voltage distribution by using multiple power supplies and load impedances on the end of the RF electrode. The uniformity errors decrease from ±20% to ±2.4% (27.12MHz) and from ±40% to ±5.9% (54.24MHz). Experimental results of the film uniformity will be discussed in dependence on excitation frequencies and the deposition parameters.

Real Time Spectroscopic Ellipsometry of Amorphous Silicon Grown at High Deposition Rates by Hot-Wire CVD

2002 ◽  
Vol 715 ◽  
Author(s):  
Brent P. Nelson ◽  
Dean H. Levi
Keyword(s):  
Amorphous Silicon ◽  
Real Time ◽  
Deposition Rate ◽  
Spectroscopic Ellipsometry ◽  
Chemical Vapor ◽  
Early Time ◽  
Growth Conditions ◽  
General Tendency ◽  
Hot Wire ◽  
Deposition Rates

AbstractWe use real-time spectroscopic ellipsometry (RTSE) for in-situ characterization of the optical properties and surface roughness (Rs) of hydrogenated amorphous silicon (a-Si:H) grown by hot-wire chemical vapor deposition (HWCVD) with varying deposition rates (5 to 120 Å/s). Early time evolution of the Rs during growth is remarkably similar for all deposition rates. During the first few Ås of growth, there is a sharp increase in Rs as the a-Si:H nucleates in separate islands. This is followed by a reduction of Rs as these areas coalesce into a bulk film, which occurs at an average thickness of 100 Å. After coalescence the Rs rises to a stable value that is dependent upon growth conditions with a general tendency for the Rs to increase with growth rate. However, neither the Rs nor the material electronic properties are unique for a given deposition rate. Films grown under high silane flow and low pressure have a better photoresponse and a lower Rs than films grown at the same deposition rate but with low silane flow and high pressure. We observe a stronger correlation of film properties with Rs than with deposition rate; namely a monotonic decrease in photo-response, and increase in optical gap, with increasing Rs.

Consideration of Femtosecond Laser-Induced Effect on Semiconductor Material SiC Substrate for CMP Processing

2015 ◽  
Vol 799-800 ◽  
pp. 458-462
Author(s):  
Cheng Wu Wang ◽  
Syuhei Kurokawa ◽  
Toshiro Doi ◽  
Yasuhisa Sano ◽  
Hideo Aida ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Femtosecond Laser ◽  
Surface Morphology ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Lower Surface ◽  
Before And After ◽  
Single Crystal Sic ◽  
Sic Wafer

In this paper, lapped C-face of single crystal SiC wafer was irradiated by femtosecond laser. Chemical mechanical polishing (CMP) was then carried out to polish the irradiated SiC C-face. The authors compared the results of femtosecond laser-assisted CMP process. A white-light interferometer was used to investigate the surface morphology of the processed SiC substrate before and after laser irradiation. It was found that the material removal rate (MRR) of the irradiated substrate is about 3 times higher than that of the substrate not treated by femtosecond laser. In addition, lower surface roughness was realized after femtosecond laser assisted CMP process.

Peak-To-Peak Voltage (Vp-p) on Rf Powered-Electrode and Sensitivity of Amorphous Silicon (A-Si) Photoreceptor

1990 ◽  
Vol 192 ◽  
Author(s):  
Toshinori Yamazaki ◽  
Nobuaki Kobayashi ◽  
Satoshi Takahashi ◽  
Tatsuo Nakanishi
Keyword(s):  
Amorphous Silicon ◽  
Cross Sections ◽  
Rare Gases ◽  
Dilution Ratio ◽  
Peak Voltage ◽  
Molecular Gases ◽  
Deposition Parameters ◽  
Dc Bias ◽  
Ramsauer Effect ◽  
Peak Value

ABSTRACTIt has been found that photosensitivity of amorphous silicon (a-Si) photoreceptor fabricated by g1ow-discharge decomposition of SiH4 – B2H6 – Ar has specific relation to peak-to-peak value of Rf (13.5 MHz) voltage (Vp - p) and DC bias voltage (Vdc) on the Rf powered-electrode. The lower the Vp - p value is depressed, the higher the photosensitivity is improved. Dependences of the Vp - p value on deposition parameters such as gas pressure, distance between Rf powered-e1ectrode and aluminum substrate, Rf electric power and dilution ratio of SiH4 to Ar seem to indicate correlation of Vp - p with electron energy and electron density in the plasma.Furthermore, the Vp - p and Vdc values have been measured in plasma of He, Ne (rare-gases with no Ramsauer effect), Ar, Kr, Xe (rare-gases with Ramsauer effect), and H2, N2, CH4, SiH4 (molecular-gases): Specific behaviors in Vp - p and Vdc seem to have correlation with collision cross - sections of electrons (with the energy of 2 ∼ 10 eV) in these gases.

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