Studies of SiH2Ci2/H2 Gas Phase Chemistry for Selective Thin Film Growth of Crystalline Silicon, c-Si, Using Remote Plasma Enhanced Chemical Vapor Deposition

1991 ◽  
Vol 220 ◽  
Author(s):  
J. A. Theil ◽  
G. Lucovsky ◽  
S. V. Hattangady ◽  
G. G. Fountain ◽  
R. J. Markunas
Keyword(s):  
Gas Phase ◽  
Film Growth ◽  
Crystalline Silicon ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Film Deposition ◽  
Selective Deposition ◽  
Gas Phase Chemistry ◽  
Phase Chemistry

ABSTRACTConventional high temperature, >800°C, CVD processes, utilizing SiH2Ci2 promote selective deposition of c-Si onto c-Si, but not on SiO2 surfaces. We show that low temperature, 300°C remote PECVD, with rf-excited He plasmas, and SiH2Ci2 and H2 injected downstream, also selectively deposits c-Si on c-Si and not SiO2 surfaces. This preliminary study employs in-situ mass spectrometry, MS, to determine the species responsible for selective deposition process reaction pathways. These MS studies suggest that species responsible for film deposition are Si-containing fragments of the SiH2Ci2 molecule, e.g., SiH2Ci, SiCi2H, etc., while the species responsible for inhibiting deposition on the SiO2 surfaces are by-products of the break-up of the SiH2Ci2 molecule in the gas phase, e.g., H-atoms, HCI and H2Ci+ ions.

Effect of pressure on the gas-phase chemistry when using monomethylsilane and dimethylsilane in hot-wire chemical vapor deposition

2015 ◽  
Vol 93 (1) ◽  
pp. 82-90 ◽  
Author(s):  
Rim Toukabri ◽  
Yujun Shi
Keyword(s):  
Free Radical ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Phase Reaction ◽  
Hot Wire ◽  
Gas Phase Reaction ◽  
Gas Phase Chemistry ◽  
Phase Chemistry

The effect of source gas pressure on the gas-phase reaction chemistry of dimethylsilane (DMS) and monomethylsilane (MMS) in the hot-wire chemical vapor deposition process has been studied by examining the secondary gas-phase reaction products in a reactor using a soft laser ionization source coupled with mass spectrometry. For DMS, the increase in sample pressure has resulted in the formation of small hydrocarbons, including ethene, acetylene, propene, and propyne. This leads to a switch from silylene dominant chemistry to a free radical dominant one with the pressure increase at low filament temperatures of 1200 and 1300 °C. At the lower pressure of 0.12 Torr, the formation of 1,1,2,2-tetramethyldisilane by dimethylsilylene insertion reaction into the Si–H bond in DMS is favored over trimethylsilane produced from a free radical recombination reaction for a short reaction time. However, when the pressure is increased by 10 times, the gas-phase chemistry becomes dominated by the formation of trimethylsilane. We have demonstrated that trapping of the corresponding active intermediates by the small hydrocarbons produced in situ is responsible for the observed switch. In the study with MMS, the gas-phase chemistry is dominated by the formation of 1,2-dimethyldisilane and 1,3-disilacyclobutane at both pressures of 0.48 and 1.2 Torr. Unlike DMS, the gas-phase reaction chemistry with MMS does not involve free radicals, which are the precursors to produce small hydrocarbons. The absence of small hydrocarbons formed in situ with MMS explains the preservation in chemistry upon the increase in pressure when MMS is used as a source gas.

scholarly journals Area Selective Deposition of Iron Films Using Temperature Sensitive Masking Materials and Plasma Electrons as Reducing Agents

2021 ◽  
Author(s):  
Hama Nadhom ◽  
Yusheng Yuan ◽  
Polla Rouf ◽  
Niclas Solin ◽  
Henrik Pedersen
Keyword(s):  
Photoelectron Spectroscopy ◽  
Film Growth ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Reducing Agents ◽  
Film Deposition ◽  
Chemical Vapor Deposition Method ◽  
Temperature Sensitive ◽  
Film Material ◽  
Selective Deposition

<p>potential of area selective deposition (ASD) with a newly developed chemical vapor deposition method, which utilize plasma electrons as reducing agents for deposition of metal-containing films, is demonstrated using temperature sensitive polymer-based masking materials. The masking materials tested were polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA), polystyrene (PS), parafilm, Kapton tape, Scotch tape, and office paper. The masking materials were all shown to prevent film growth on the masked area of the substrate without being affected by the film deposition process. X-ray photoelectron spectroscopy analysis confirms that the films deposited consist mainly of iron, whereas no film material is found on the masked areas after mask removal. SEM analysis of films deposited with non-adhesive masking materials show that film growth extended for a small distance underneath the masking material, indicating that the CVD process with plasma electrons as reducing agents is not a line-of-sight deposition technique. The reported methodology introduces an inexpensive and straightforward approach for ASD that opens for exciting new possibilities for robust and less complex area selective metal-on-metal deposition. </p>

scholarly journals Simulation of Gas-Phase Chemistry for Selected Carbon Precursors in Epitaxial Growth of SiC

2013 ◽  
Vol 740-742 ◽  
pp. 213-216 ◽  
Author(s):  
Örjan Danielsson ◽  
Pitsiri Sukkaew ◽  
Milan Yazdanfar ◽  
Olof Kordina ◽  
Erik Janzén
Keyword(s):  
Gas Phase ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Reaction Model ◽  
Phase Reaction ◽  
Gas Phase Chemistry ◽  
The Past ◽  
Phase Chemistry ◽  
Hydrocarbon Chemistry ◽  
Made In

Numerical simulations are one way to obtain a better and more detailed understanding of the chemical vapor deposition process of silicon carbide. Although several attempts have been made in this area during the past ten years, there is still no general model valid for any range of process parameters and choice of precursors, that can be used to control the growth process, and to optimize growth equipment design. In this paper a first step towards such a model is taken. Here, mainly the hydrocarbon chemistry is studied by a detailed gas-phase reaction model, and comparison is made between C3H8 and CH4 as carbon precursor. The results indicate that experimental differences, which previous models have been unable to predict, may be explained by the new model.

scholarly journals Gas Phase Chemistry of Trimethylboron in Thermal Chemical Vapor Deposition

2017 ◽  
Vol 121 (47) ◽  
pp. 26465-26471 ◽  
Author(s):  
Mewlude Imam ◽  
Laurent Souqui ◽  
Jan Herritsch ◽  
Andreas Stegmüller ◽  
Carina Höglund ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Thermal Chemical Vapor Deposition ◽  
Gas Phase Chemistry ◽  
Phase Chemistry

scholarly journals Methylamines as Nitrogen Precursors in Chemical Vapor Deposition of Gallium Nitride

2018 ◽  
Author(s):  
Karl Rönnby ◽  
Sydney C. Buttera ◽  
Polla Rouf ◽  
Sean Barry ◽  
Lars Ojamäe ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Surface Chemistry ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Electronic Device ◽  
Chemical Vapor ◽  
Group 13 ◽  
Gas Phase Chemistry ◽  
Device Applications ◽  
Phase Chemistry

Chemical vapor deposition (CVD) is one of the most important techniques for depositing thin films of the group 13 nitrides (13-Ns), AlN, GaN, InN and their alloys, for electronic device applications. The standard CVD chemistry for 13-Ns use ammonia as the nitrogen precursor, however, this gives an inefficient CVD chemistry forcing N/13 ratios of 100/1 or more. Here we investigate the hypothesis that replacing the N-H bonds in ammonia with weaker N-C bonds in methylamines will permit better CVD chemistry, allowing lower CVD temperatures and an improved N/13 ratio. Quantum chemical computations shows that while the methylamines have a more reactive gas phase chemistry, ammonia has a more reactive surface chemistry. CVD experiments using methylamines failed to deposit a continuous film, instead micrometer sized gallium droplets were deposited. This study shows that the nitrogen surface chemistry is most likely more important to consider than the gas phase chemistry when searching for better nitrogen precursors for 13-N CVD.

scholarly journals Methylamines as Nitrogen Precursors in Chemical Vapor Deposition of Gallium Nitride

2019 ◽  
Author(s):  
Karl Rönnby ◽  
Sydney C. Buttera ◽  
Polla Rouf ◽  
Sean Barry ◽  
Lars Ojamäe ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Surface Chemistry ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Electronic Device ◽  
Chemical Vapor ◽  
Group 13 ◽  
Gas Phase Chemistry ◽  
Device Applications ◽  
Phase Chemistry

Chemical vapor deposition (CVD) is one of the most important techniques for depositing thin films of the group 13 nitrides (13-Ns), AlN, GaN, InN and their alloys, for electronic device applications. The standard CVD chemistry for 13-Ns use ammonia as the nitrogen precursor, however, this gives an inefficient CVD chemistry forcing N/13 ratios of 100/1 or more. Here we investigate the hypothesis that replacing the N-H bonds in ammonia with weaker N-C bonds in methylamines will permit better CVD chemistry, allowing lower CVD temperatures and an improved N/13 ratio. Quantum chemical computations shows that while the methylamines have a more reactive gas phase chemistry, ammonia has a more reactive surface chemistry. CVD experiments using methylamines failed to deposit a continuous film, instead micrometer sized gallium droplets were deposited. This study shows that the nitrogen surface chemistry is most likely more important to consider than the gas phase chemistry when searching for better nitrogen precursors for 13-N CVD.

scholarly journals Depletion of 15N in the center of L1544: Early transition from atomic to molecular nitrogen?

2018 ◽  
Vol 615 ◽  
pp. L16 ◽  
Author(s):  
K. Furuya ◽  
Y. Watanabe ◽  
T. Sakai ◽  
Y. Aikawa ◽  
S. Yamamoto
Keyword(s):  
Gas Phase ◽  
Molecular Nitrogen ◽  
Abundance Ratio ◽  
Elemental Abundance ◽  
Evolutionary Stage ◽  
Gas Phase Chemistry ◽  
Far Ultraviolet ◽  
Phase Chemistry ◽  
Grain Surface

We performed sensitive observations of the N15ND+(1–0) and 15NND+(1–0) lines toward the prestellar core L1544 using the IRAM 30 m telescope. The lines are not detected down to 3σ levels in 0.2 km s−1 channels of ~6 mK. The non-detection provides the lower limit of the 14N/15N ratio for N2D+ of ~700–800, which is much higher than the elemental abundance ratio in the local interstellar medium of ~200–300. The result indicates that N2 is depleted in 15N in the central part of L1544, because N2D+ preferentially traces the cold dense gas, and because it is a daughter molecule of N2. In situ chemistry is probably not responsible for the 15N depletion in N2; neither low-temperature gas phase chemistry nor isotope selective photodissociation of N2 explains the 15N depletion; the former prefers transferring 15N to N2, while the latter requires the penetration of interstellar far-ultraviolet (FUV) photons into the core center. The most likely explanation is that 15N is preferentially partitioned into ices compared to 14N via the combination of isotope selective photodissociation of N2 and grain surface chemistry in the parent cloud of L1544 or in the outer regions of L1544, which are not fully shielded from the interstellar FUV radiation. The mechanism is most efficient at the chemical transition from atomic to molecular nitrogen. In other words, our result suggests that the gas in the central part of L1544 has previously gone trough the transition from atomic to molecular nitrogen in the earlier evolutionary stage, and that N2 is currently the primary form of gas-phase nitrogen.

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