Low Temperature Deposited Highly-Conductive N-type SiC Thin Films

1997 ◽  
Vol 472 ◽  
Author(s):  
Kuan-Lun Cheng ◽  
Huang-Chung Cheng ◽  
Wen-Horng Lee ◽  
Chiapyng Lee ◽  
Tri-Rung Yew
Keyword(s):  
Low Temperature ◽  
Film Growth ◽  
Thin Film Transistor ◽  
Impurity Scattering ◽  
Gas Analyzer ◽  
Flow Rates ◽  
Sic Film ◽  
Dopant Source ◽  
Sic Films

ABSTRACTLow-temperature deposited highly-conductive SiC films has long been a goal for many researchers involved in hetero-junction bipolar transistor, thin-film transistor, solar cell.… etc. Here in this paper, we study the influences of the diluted PH3 flow rates on SiC film quality as well as electrical properties. PH+ was determined from residual gas analyzer to be the main dopant source. Phosphorous atoms will play a role of enhancing the SiC grain growth and resulting in a smaller film growth rate. Carrier concentrations increase monotonically with the diluted PH3 flow rates. While Hall mobility first increases than decreases with it due to a combination effect of the impurity scattering and a film quality improvement which dominates when the 1% PH3/H2 flow rate is above or below 40 seem, respectively.

Effect of Ge on SiC Film Morphology in SiC/Si Films Grown by MOCVD

1999 ◽  
Vol 572 ◽  
Author(s):  
W. L. Samey ◽  
L. Salamanca-Riba ◽  
P. Zhou ◽  
M. G. Spencer ◽  
C. Taylor ◽  
...  
Keyword(s):  
Stacking Faults ◽  
Two Dimensional ◽  
High Quality ◽  
Flow Rates ◽  
Si Substrates ◽  
Cvd Growth ◽  
Polytype Transformation ◽  
Si Films ◽  
Sic Film ◽  
Sic Films

ABSTRACTSiC/Si films generally contain stacking faults and amorphous regions near the interface. High quality SiC/Si films are especially difficult to obtain since the temperatures usually required to grow high quality SiC are above the Si melting point. We added Ge in the form of GeH2 to the reactant gases to promote two-dimensional CVD growth of SiC films on (111) Si substrates at 1000°C. The films grown with no Ge are essentially amorphous with very small crystalline regions, whereas those films grown with GeH2 flow rates of 10 and 15 sccm are polycrystalline with the 3C structure. Increasing the flow rate to 20 sccm improves the crystallinity and induces growth of 6H SiC over an initial 3C layer. This study presents the first observation of spontaneous polytype transformation in SiC grown on Si by MOCVD.

scholarly journals Role of ions in SiO2 deposition with pulsed and continuous helicon plasmas

2002 ◽  
Vol 74 (3) ◽  
pp. 401-405
Author(s):  
Christine Charles
Keyword(s):  
Low Temperature ◽  
Silicon Dioxide ◽  
Compressive Stress ◽  
Structural Properties ◽  
Film Growth ◽  
Low Pressure ◽  
Ion Flux ◽  
High Density ◽  
Silicon Dioxide Films

Good-quality silicon dioxide films have been deposited at low temperature (200 °C) using continuous and pulsed oxygen/silane plasmas coupled in a high-density, low-pressure helicon reactor. Although the total ion flux determines many of the structural properties of the deposited oxide, we have found that silicon-containing ions contribute to the film growth (up to 50 %) and appear to be responsible for the measured compressive stress.

Microcrystallinity in a-Si & a-SiC Films Made by Hg-Sensitized Photo-CVD

1989 ◽  
Vol 149 ◽  
Author(s):  
N. Saxena ◽  
C. M. Fortmann ◽  
T. W. F. Russell
Keyword(s):  
Carbon Content ◽  
Gas Phase ◽  
Growth Rates ◽  
Film Growth ◽  
Selective Etching ◽  
Gas Phase Reactions ◽  
And Diffusion ◽  
Sic Films ◽  
Reactor Pressure

ABSTRACTA model for the role of H atoms as an etchant specie during deposition of microcrystalline (μc) films of Si:H and SiC:H is explored. Growth rates and etch rates of films made by Hg-sensitized photo-CVD have been measured as a function of reactor pressure (between 5 and 0.5 torr) and H2 dilution (up to 30:1). Gas phase reactions and diffusion to the substrate of depositing and etching species, have been modelled. It is found that high H radical flux (not necessarily high H2 dilution) promotes μc film growth. There are two surface etching reactions by H radicals: (i) selective etching of uncoordinated Si surface atoms (amorphous phase) from the film, leaving behind the more etch-resistant μc phase; (ii) in SiC:H alloy systems, a selective etching of C species, causing a decrease in C incorporation into the growing microcrystalline film. Films with increasing carbon content do not contain a μc-SiC phase because hydrogen is not eliminated from the carbon containing film precursors, thus inhibiting the development of crystalline Si-C network.

scholarly journals Dissecting the Roles of Cuticular Wax in Plant Resistance to Shoot Dehydration and Low-Temperature Stress in Arabidopsis

2021 ◽  
Vol 22 (4) ◽  
pp. 1554
Author(s):  
Tawhidur Rahman ◽  
Mingxuan Shao ◽  
Shankar Pahari ◽  
Prakash Venglat ◽  
Raju Soolanayakanahally ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Low Temperature ◽  
Cold Acclimation ◽  
Water Loss ◽  
Cuticular Wax ◽  
Dehydration Stress ◽  
Wax Deposition ◽  
Cuticular Waxes ◽  
Gas Chromatography Mass Spectroscopy

Cuticular waxes are a mixture of hydrophobic very-long-chain fatty acids and their derivatives accumulated in the plant cuticle. Most studies define the role of cuticular wax largely based on reducing nonstomatal water loss. The present study investigated the role of cuticular wax in reducing both low-temperature and dehydration stress in plants using Arabidopsis thaliana mutants and transgenic genotypes altered in the formation of cuticular wax. cer3-6, a known Arabidopsis wax-deficient mutant (with distinct reduction in aldehydes, n-alkanes, secondary n-alcohols, and ketones compared to wild type (WT)), was most sensitive to water loss, while dewax, a known wax overproducer (greater alkanes and ketones compared to WT), was more resistant to dehydration compared to WT. Furthermore, cold-acclimated cer3-6 froze at warmer temperatures, while cold-acclimated dewax displayed freezing exotherms at colder temperatures compared to WT. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis identified a characteristic decrease in the accumulation of certain waxes (e.g., alkanes, alcohols) in Arabidopsis cuticles under cold acclimation, which was additionally reduced in cer3-6. Conversely, the dewax mutant showed a greater ability to accumulate waxes under cold acclimation. Fourier Transform Infrared Spectroscopy (FTIR) also supported observations in cuticular wax deposition under cold acclimation. Our data indicate cuticular alkane waxes along with alcohols and fatty acids can facilitate avoidance of both ice formation and leaf water loss under dehydration stress and are promising genetic targets of interest.

The Role of Li2CO3and PbO in the Low-Temperature Sintering of Sr, K, Nb (SKN)-Doped PZT

2009 ◽  
Vol 92 (6) ◽  
pp. 1203-1207 ◽  
Author(s):  
Niall J. Donnelly ◽  
Thomas R. Shrout ◽  
Clive A. Randall
Keyword(s):  
Low Temperature ◽  
Low Temperature Sintering

Spin-Lattice Coupling and Peculiarities of Magnetic Behavior of Ferrimagnetic Ludwigites Mn0.52+M1.52+Mn3+BO5(M=Cu, Ni)

2015 ◽  
Vol 233-234 ◽  
pp. 133-136 ◽  
Author(s):  
Leonard Bezmaternykh ◽  
Evgeniya Moshkina ◽  
Evgeniy Eremin ◽  
Maxim Molokeev ◽  
Nikita Volkov ◽  
...  
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Magnetic Anisotropy ◽  
Single Crystals ◽  
Magnetic Behavior ◽  
Temperature Hysteresis ◽  
Spin Lattice ◽  
Field Magnetization ◽  
Lattice Coupling

Temperature-field and orientational magnetization dependences of single crystals were measured. Both samples demonstrate significant field-depending temperature hysteresis and low-temperature counter field magnetization. The correlation of orientational dependences of these effects and magnetic anisotropy is analyzed; the role of spin-lattice interactions is discussed.

Role of Surface Reconstruction and External Ion Beam in the Growth Kinetics of III-V Molecular Beam Epitaxy

1987 ◽  
Vol 94 ◽  
Author(s):  
S. B. Ogale ◽  
M. Thomsen ◽  
A. Madhukar
Keyword(s):  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Surface Reconstruction ◽  
Molecular Beam ◽  
Ion Beam ◽  
Growth Front ◽  
Kinetic Rates ◽  
Kinetics Of ◽  
Low Temperature Epitaxy

ABSTRACTComputer simulations of III-V molecular beam epitaxy (MBE) show that surface reconstruction induced modulation of kinetic rates could give rise to ordering in alloys. Results are also presented for the possible influence of an external ion beam in achieving low temperature epitaxy as well as smoother growth front under usual conditions.

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