scholarly journals Sputter Deposition of Semiconductor Superlattices for Thermoelectric Applications

1996 ◽  
Vol 450 ◽  
Author(s):  
Andrew V. Wagner ◽  
Ronald J. Foreman ◽  
Joseph C. Farmer ◽  
Troy W. Barbee
Keyword(s):  
Film Growth ◽  
Lead Telluride ◽  
Deposition Process ◽  
Growth Conditions ◽  
Sputter Deposition ◽  
High Rate ◽  
Dramatic Improvement ◽  
High Deposition Rate ◽  
High Quality ◽  
Quantum Confined

ABSTRACTTheoretical dramatic improvement of the thermoelectric properties of materials by using quantum confinement in novel semiconductor nanostructures has lead to considerable interest in the thermoelectric community. Therefore, we are exploring the critical materials issues for fabrication of quantum confined structures by magnetron sputtering in the lead telluride and bismuth telluride families of materials. We have synthesized modulated structures from thermoelectric materials with bilayer periods of as little as 3.2 nm and shown that they are stable at deposition temperatures high enough to grow quality films. Issues critical to high quality film growth have been investigated such as nucleation and growth conditions and their effect on crystal orientation and growth morphology. These investigations show that nucleating the film at a temperature below the growth temperature of optimum electronic properties produces high quality films. Our work with sputter deposition, which is inherently a high rate deposition process, builds the technological base necessary to develop economical production of these advanced materials. High deposition rate is critical since, even if efficiencies comparable with CFC based refrigeration systems can be achieved, large quantities of quantum confined materials will be necessary for cost-competitive uses.

High-rate a-Si:H and μc-Si:H Film Growth Studied by Advanced Plasma and in situ Film Diagnostics

2002 ◽  
Vol 715 ◽  
Author(s):  
W.M.M. Kessels ◽  
P.J. van den Oever ◽  
J.P.M. Hoefnagels ◽  
J. Hong ◽  
I.J. Houston ◽  
...  
Keyword(s):  
Film Growth ◽  
Film Studies ◽  
Interface Layer ◽  
Surface Reactivity ◽  
Attenuated Total Reflection ◽  
High Rate ◽  
High Deposition Rate ◽  
Basic Insight ◽  
Insight Into

AbstractPlasma and in situ film studies have been applied to the expanding thermal plasma to obtain basic insight into the deposition of a-Si:H and μc-Si:H at high rates (> 10 Å/s). A study of the density of plasma radicals (Si, SiH, SiH3) and of the radicals' surface reactivity has revealed that SiH3 is the most important radical for the growth of both materials. In situ attenuated total reflection infrared spectroscopy and spectroscopic ellipsometry have revealed a thick interface layer and consequently long incubation time for the materials deposited at a high deposition rate.

The Effects of Collimator Life Time on the Ti and Tin Film Growth Rates and Conformalities in Sputter Deposition Processes: Experiments and Simulations

1995 ◽  
Vol 387 ◽  
Author(s):  
Hung Liao ◽  
Hannes Stippel ◽  
Krishna Reddy ◽  
Sam Geha ◽  
Kevin Brown ◽  
...  
Keyword(s):  
Growth Rates ◽  
Film Growth ◽  
Side Wall ◽  
Life Time ◽  
Deposition Process ◽  
Sputter Deposition ◽  
Cross Sectional ◽  
Tin Film ◽  
Side Walls ◽  
Deposition Processes

AbstractExperimental and simulation studies were conducted in an attempt to understand the effects of collimator life time on the Ti and TiN film growth rates and conformalities in sputter deposition processes. The Ti and TiN films were deposited with and without collimation. The hexagonal cells of the collimator used in this study have a 1:1 aspect ratio. A Monte Carlo based simulator was used to calculate the angular distributions of species exiting from a collimator cell and the percentage decrease in the rate of film growth as a function of the collimator life time. Then, a low pressure deposition process simulator, EVOLVE, was used to predict the conformalities of deposited films in contacts or vias, assuming that the films were uniformly deposited on the side-walls of collimator cells. We conclude that the loss in growth rate is largely due to the shrinkage in the cross sectional area of the collimator cell inlets. We arrive at this conclusion after comparing an estimated film thickness on the collimator side-walls with experimental measurements. With extended collimator usage, the predicted and experimental film profiles in contacts or vias show increasing bottom coverage and decreasing side-wall coverages.

Sputter Deposition of GMR Spin Valves

2000 ◽  
Vol 616 ◽  
Author(s):  
W. Zou ◽  
X.W. Zhou ◽  
J.J. Quan ◽  
Y.G. Yang ◽  
H.N.G. Wadley ◽  
...  
Keyword(s):  
Film Growth ◽  
Growth Conditions ◽  
Input Power ◽  
Sputter Deposition ◽  
Atomic Scale ◽  
Spin Valves ◽  
Monte Carlo Techniques ◽  
Surfaces And Interfaces ◽  
Interfacial Structures ◽  
Series Of Experiments

AbstractRadio frequency (RF) diode sputtering has been used for the growth of giant magnetoresistive (GMR) metal multilayers. Control of the atomic-scale structure of the surfaces and interfaces within these films is critical for GMR applications. A systematic series of experiments have been conducted to evaluate the dependence of the magnetotransport properties upon the growth conditions (i.e. background pressure, input power) for NiFeCo/CoFe/CuAgAu spin valves during RF diode sputter deposition. By using computational fluid dynamics, plasma, molecular dynamics, and various Monte Carlo techniques, a multiscale modeling approach has investigated the atomic assembly events during film growth. Energetic metal atoms and inert gas ion fluxes are shown to have very strong effects upon interfacial structures. The insights gained have led to novel deposition strategy propopositions for interface morphology control.

High Deposition Rate Amorphous Silicon Alloy Xerographic Photoreceptor

1985 ◽  
Vol 49 ◽  
Author(s):  
S.J. Hudgens ◽  
A.G. Johncock
Keyword(s):  
Glow Discharge ◽  
Amorphous Silicon ◽  
Decay Time ◽  
Plasma Deposition ◽  
Deposition Process ◽  
Utilization Efficiency ◽  
High Deposition Rate ◽  
High Quality ◽  
Silicon Alloy ◽  
Gas Utilization

AbstractA new multilayer amorphous silicon alloy photoreceptor has been deposited at rates exceeding 36 µm/hr. using 2.45 GHz microwave glow discharge. The device whose structure is Al/a-Si:H:F (B-300)/a-Si:H:F (B-10)/a-Si:H:F:C is deposited in a powderless plasma deposition process which exhibits gas utilization efficiency approaching 100%. The xerographic performance of a 28µm device is: Vsat∼1100 V for a +7 KV corona; dark half decay time ≃5 sec; and photosensitivity ∼0.3 µJ/cm2 at λ = 650 nm. Stable, high quality xerographic images are obtained with these photoreceptors.

Control of growth process for obtaining high-quality a-SiO:H

2014 ◽  
Vol 92 (7/8) ◽  
pp. 582-585 ◽  
Author(s):  
Yasushi Sobajima ◽  
Shota Kinoshita ◽  
Shinnosuke Kakimoto ◽  
Ryoji Okumoto ◽  
Chitose Sada ◽  
...  
Keyword(s):  
Growth Process ◽  
Film Growth ◽  
Defect Density ◽  
Chemical Species ◽  
Optical Emission ◽  
State Density ◽  
Primary Electron ◽  
High Rate ◽  
High Quality ◽  
Simple Simulation

Film-growth process of hydrogenated amorphous silicon–oxygen alloys (a-SiO:H) from CO2/(CO2 + SiH4) plasma has been investigated to control the optoelectronic properties in the resulting materials. Optical emission spectroscopy results and simple simulation results for steady-state density of chemical species in the plasma indicate that main film-growth precursors for a-SiO:H are SiH3, OH, and O. Si dangling-bond defect density is drastically increased in a-SiO:H when increasing the CO2 gas ratio in CO2/(CO2 + SiH4) plasma, being caused by the increase in the contribution ratio of Si-related short-lifetime species (SiHx, x < 2) to film growth owing to a severe SiH4-molecule depletion because of high-rate consumption reaction of SiH4 with O produced from CO2 in the plasma. Considering the primary electron impact dissociation reactions of source gas molecules and several secondary chemical reactions in the plasma, the guiding principle for obtaining high quality a-SiO:H has been proposed.

Comparative Study of Differently Grown 3C-SiC Single Crystals with Birefringence Microscopy

2008 ◽  
Vol 600-603 ◽  
pp. 71-74 ◽  
Author(s):  
Didier Chaussende ◽  
Frédéric Mercier ◽  
Roland Madar ◽  
Michel Pons
Keyword(s):  
High Temperature ◽  
Comparative Study ◽  
Single Crystals ◽  
Growth Conditions ◽  
High Rate ◽  
High Quality ◽  
Bulk Growth ◽  
Stable Growth ◽  
Very High

We have investigated through birefringence microscopy, a set of 3C-SiC crystals grown with the CF-PVT process, starting from different seeds and under different growth conditions. Through self nucleation experiments, the stable growth of very high quality 3C-SiC crystals at high temperature (2100°C) and at high rate (roughly 0.2 mm/h) is demonstrated. The possibility to develop bulk growth of 3C-SiC crystals is discussed.

Macro-Trench Studies of Surface Reaction Probability of a-Si:H Film Growth

1992 ◽  
Vol 258 ◽  
Author(s):  
A. Nuruddin ◽  
J. R. Doyle ◽  
J. R. Abelson
Keyword(s):  
Hollow Cathode ◽  
Surface Reaction ◽  
Film Growth ◽  
State Of The Art ◽  
Sputter Deposition ◽  
Reactive Magnetron ◽  
High Quality ◽  
Mitigating Factors ◽  
Magnetron Sputter Deposition ◽  
Magnetron Sputter

ABSTRACTUsing a “macro-trench” technique, the surface reaction probabilities β of the a-Si:H growth precursors for remote hollow cathode silane discharge (HC) and reactive magnetron sputter deposition (RMS) are measured. Both deposition methods produce state of the art photo-electronic quality a-Si:H. For the HC case, β= 0.28 ± 0.05, whereas for RMS deposition β ≈ 0.97 ± 0.05. We conclude that β is not universally correlated with film quality, and discuss mitigating factors present in RMS deposition that permit high quality film to be deposited despite the high film precursor reactivity.

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