RF Power Dependence of the Material Properties of PECVD Silicon Dioxide

1989 ◽  
Vol 165 ◽  
Author(s):  
J. D. Chapple-Sokol ◽  
E. Tiemey ◽  
J. Batey
Keyword(s):  
Nitrous Oxide ◽  
Silicon Dioxide ◽  
Power Density ◽  
Material Properties ◽  
Deposition Process ◽  
Power Dependence ◽  
Rf Power ◽  
Deposition Rates ◽  
Physical Integrity ◽  
Silane Concentration

AbstractSilicon dioxide films deposited from the PECVD reaction of silane and nitrous oxide in the presence of helium were studied to determine the effects of RF power on the deposition process. Increased RF power density yielded oxides which were structurally and chemically more homogeneous. The combination of elevated power density with increased silane concentration resulted in the deposition of films of high electrical and physical integrity at high deposition rates.

Gate Quality Oxides Prepared by Rapid Thermal Chemical Vapor Deposition

1993 ◽  
Vol 334 ◽  
Author(s):  
R.T. Kuehn ◽  
X. Xu ◽  
D.J. Holcombe ◽  
V. Misra ◽  
J.J. Wortman ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Silicon Dioxide ◽  
Flow Rate ◽  
Rate Ratio ◽  
Surface Cleaning ◽  
Flow Rate Ratio ◽  
Deposition Rates ◽  
Gate Oxides ◽  
Silicon Silicon ◽  
Silicon Silicon Dioxide Interface

AbstractAs the feature size of MOSFET devices shrink, issues such as thermal budget associated with controlling channel doping profiles and oxide growth kinetics raise concerns about using thermally grown furnace oxides for deep-submicron device applications. To address these concerns, we have developed a new RTCVD oxide process using a gas system of silane and nitrous oxide. The RTCVD oxides are deposited in a lamp-heated, cold wall, RTP system. Deposition rates ranging from 55 Å/min. to 624 Å/min. can be achieved at 800°C with silane nitrous oxide flow rate ratio of 2% and total pressure ranging from 3 to 10 Torr. The results indicate that this RTCVD process can be used to deposit both thin gate and thick isolation insulators for single wafer processing. Deposition rates of the RTCVD oxides exhibit a nonlinear dependence on the total deposition pressure. Electrical characterization of the as-deposited RTCVD oxides shows a mid-gap interface trap density of < 5×1010 eV−1 cm−2 and an average breakdown field of 13MV/cm. AES, RBS and TEM analyses have been used to study surface cleaning effects on the silicon-silicon dioxide interface quality and to determine the chemical composition of the RTCVD oxides. The results show that RTCVD oxides with stoichiometric composition and atomic flat silicon-silicon dioxide interface can be achieved using silane nitrous oxide flow rate ratio of <2%. I-V characteristics and transconductance degradation under hot carrier stress for MOSFET's using as-deposited RTCVD gate oxides have been found to be comparable to those of MOSFET's using thermal gate oxides.

Reduction of Internal Stress of a-Si:H Films by in Situ Measurements of Optical Emission Intensity from SiH4 Plasma

1990 ◽  
Vol 192 ◽  
Author(s):  
K. Tamahashi ◽  
M. Wakagi ◽  
F. Ishikawa ◽  
T. Kaneko ◽  
K. Tamura ◽  
...  
Keyword(s):  
Internal Stress ◽  
Power Density ◽  
Emission Intensity ◽  
Optical Emission ◽  
Deposition Process ◽  
Rf Power ◽  
Stress Changes ◽  
Hydrogenated Amorphous ◽  
Emission Intensity Ratio

ABSTRACTA parameter which determine internal stress of hydrogenated amorphous silicon (a-Si:H) prepared by plasma CVD method has been investigated to prevent a peeling off or crack forming problem. It is clarified that the internal stress changes from tension to compression as a function of supplied rf power density during deposition process. Supplied rf power density is closely connected to H o and SiH* optical emission intensity ratio (H α /SiH* ) of CVD plasma. Ve find that the internal stress can be reduced remarkably by controlling this ratio to 0.3. This H α/SiH* parameter has a superiority that the internal stress can be in situ controlled.

Investigation of ultra-thin films of YBa2Cu3O7−δ grown on MgO

1990 ◽  
Vol 48 (4) ◽  
pp. 6-7
Author(s):  
S.K. Streiffer ◽  
C.B. Eom ◽  
J.C. Bravman ◽  
T.H. Geballet
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Deposition Process ◽  
Nucleation And Growth ◽  
Multilayer Structures ◽  
Rf Power ◽  
Oxygen Loss ◽  
Transmission Electron ◽  
Single Target ◽  
Mtorr Argon

The study of very thin (<15 nm) YBa2Cu3O7−δ (YBCO) films is necessary both for investigating the nucleation and growth of films of this material and for achieving a better understanding of multilayer structures incorporating such thin YBCO regions. We have used transmission electron microscopy to examine ultra-thin films grown on MgO substrates by single-target, off-axis magnetron sputtering; details of the deposition process have been reported elsewhere. Briefly, polished MgO substrates were attached to a block placed at 90° to the sputtering target and heated to 650 °C. The sputtering was performed in 10 mtorr oxygen and 40 mtorr argon with an rf power of 125 watts. After deposition, the chamber was vented to 500 torr oxygen and allowed to cool to room temperature. Because of YBCO’s susceptibility to environmental degradation and oxygen loss, the technique of Xi, et al. was followed and a protective overlayer of amorphous YBCO was deposited on the just-grown films.

3.8 W/mm RF Power Density for ALD Al2O3-Based Two-Dimensional Hole Gas Diamond MOSFET Operating at Saturation Velocity

2019 ◽  
Vol 40 (2) ◽  
pp. 279-282 ◽  
Author(s):  
Shoichiro Imanishi ◽  
Kiyotaka Horikawa ◽  
Nobutaka Oi ◽  
Satoshi Okubo ◽  
Taisuke Kageura ◽  
...  
Keyword(s):  
Power Density ◽  
Two Dimensional ◽  
Rf Power ◽  
Saturation Velocity

Top-gate ZnO-based TFTs by RF Sputtering

2007 ◽  
Vol 1035 ◽  
Author(s):  
Shahrukh Khan ◽  
Abbas jamshidi-Roudbari ◽  
Miltiadis Hatalis
Keyword(s):  
Thin Films ◽  
Power Density ◽  
Rf Sputtering ◽  
Visible Spectrum ◽  
Drain Current ◽  
Channel Length ◽  
Zno Thin Films ◽  
Chamber Pressure ◽  
Rf Power ◽  
Bridge Structures

AbstractThis work emphasizes room temperature deposition and fabrication of top-gated staggered structure ZnO-TFTs and integration of ZnO-TFT based simple logic circuits. We synthesized ZnO thin films by RF sputtering in an Ar/Oxygen ambience with no intentional heating of the substrates. The electrical, optical and structural properties of the ZnO thin films can be well-controlled by altering process parameters such as RF power density and relative Oxygen partial pressure. Typical deposition was carried out at a chamber pressure of 15 mTorr, Ar/Oxygen flow rates of 15 sccm/1 sccm and RF power density of 3W/cm2. The resistivity of the as-deposited films was between 104-106 Ù-cm with high optical transparency (>80%) in the visible spectrum and minimal surface roughness as detected by high-resolution AFM imaging. Gated van der Pauw and Kelvin-bridge structures were lithographically patterned to asses ZnO channel resistance. In the completed devices, a dual-stack (Ta2O5/SiO2) dielectric layer was effective in suppressing gate-leakage current below 10 pA and enabled depletion-mode ZnO-TFT operation exhibiting hard saturation. A Ti/Au metallization scheme was adopted to provide good ohmic contact to ZnO. TFTs retained well-behaved transfer characteristics down to a channel length of 4 ìm with on/off drain current ratio exceeding 105, threshold voltage between -15 V to -5 V and inverse sub-threshold slope of around 1.75 V/decade.

High Efficiency Molding by Real-Time Control of Distance Between Nozzle and Melt Pool in Directed Energy Deposition Process

2020 ◽  
Author(s):  
Kengo Aizawa ◽  
Masahiro Ueda ◽  
Teppei Shimada ◽  
Hideki Aoyama ◽  
Kazuo Yamazaki
Keyword(s):  
Additive Manufacturing ◽  
Real Time ◽  
Material Properties ◽  
High Efficiency ◽  
Dimensional Accuracy ◽  
Deposition Process ◽  
Deposition Efficiency ◽  
Experimental Results ◽  
Real Time Control ◽  
Molding Process

Abstract Laser metal deposition (LMD) is an additive manufacturing technique, whose performance can be influenced by a considerable number of factors and parameters. Typically, a powder is carried by an inert gas and sprayed by a nozzle, with a coaxial laser beam passing through the nozzle and overlapping the powder flow, thereby generating a molten material pool on a substrate. Monitoring the evolution of this process allows for a better comprehension and control of the process, thereby enhancing the deposition quality. As the metal additive manufacturing mechanism has not yet been elucidated, it is not clear how process parameters affect material properties, molding accuracy, and molding efficiency. When cladding is performed under uncertain conditions, a molded part with poor material properties and dimensional accuracy is created. In this paper, we propose a method for high efficiency molding by controlling the distance between the head nozzle and the molten pool in real time. The distance is identified by an originally developed sensor based on a triangulation method. According to the distance, the head nozzle is automatically controlled into the optimum position. As a result, an ideal molding process can be generated, so that high efficiency molding and high-quality material properties can be obtained. Experimental results show that continuing deposition at the optimum distance assists in achieving deposition efficiency and dimensional accuracy. According to the specific experimental results of this method, the modeling efficiency was increased by 27% compared to the method without correction, and the modeling was successful with an error within 1 mm.

Microcrystalline Silicon Films Produced by RF Magnetron Sputtering and the Effect of Diffrent Ambients on their Conductivity

1989 ◽  
Vol 164 ◽  
Author(s):  
Ratnabali Berjee ◽  
A. K. Bandyopadhyay ◽  
S. N. Sharma ◽  
A. K. Patabyal ◽  
A.K. Barua
Keyword(s):  
Magnetron Sputtering ◽  
Power Density ◽  
Rf Magnetron Sputtering ◽  
Silicon Films ◽  
Critical Parameters ◽  
Rf Power ◽  
Microcrystalline Silicon ◽  
Film Properties

AbstractResults on characterisation of undoped, μc-Si:H films prepared by rf magnetron sputtering technique are presented. Highly conducting films (10−3 Δ−cm−1) were obtained at fairly low rf power density (l.2W/cm2). Critical parameters for obtaining microcrystalline phase were identified. The effect of humid ambient on film properties was looked into.

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