Effect of N2-to-TiCl4 flow rate ratio on the properties of TiN coatings formed by d.c. discharge plasma-assisted chemical vapor deposition

ABSTRACTThe parameters necessary to deposit oriented rhombohedral boron phosphide (B12P2) thin films on on-axis Si-face 6H-SiC(0001) substrates by chemical vapor deposition are reported. Ultra high purity BBr3 and PBr3 were used as reactants, with hydrogen as the carrier gas. The BBr3 to PBr3 flow rate ratio was adjusted to obtain good surface morphology of the B12P2 films. BBr3 to PBr3 ratios in the range of 1 to 1.5 produced smooth surfaces and moderate growth rates of 10μm/hr. Higher growth rates were obtained by increasing the BBr3 flow rate, but the surfaces became very rough. The c-axis of the B12P2 film was aligned with the c -axis of the substrate at temperatures between 1650°C-1700°C. The surface morphologies were investigated by SEM and the crystalline properties of the films were characterized by XRD and Raman spectroscopy.

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Effect of CS2 Flow Rate on the Formation of Aligned Carbon Microcoils

Materials Science Forum ◽

10.4028/www.scientific.net/msf.947.40 ◽

2019 ◽

Vol 947 ◽

pp. 40-46

Author(s):

Hyun Ji Kim ◽

Sung Hoon Kim

Keyword(s):

Flow Rate ◽

Vapor Deposition ◽

Rate Ratio ◽

Chemical Vapor ◽

Regular Structure ◽

Flow Rate Ratio ◽

Total Flow ◽

Total Flow Rate ◽

Flow Rates ◽

Thermal Chemical Vapor Deposition

The formation of aligned carbon microcoils could be achieved using C2H2 as a source gas and CS2 as an incorporated additive gas under thermal chemical vapor deposition system. To elucidate the ratio of C2H2/CS2 for the formation of the aligned carbon microcoils, the CS2 flow rate was first manipulated under the identical C2H2 flow rate (500sccm) condition. The formation and the alignment of carbon microcoils could be only achieved under the ratio of C2H2/CS2 = 33.3 condition, namely the flow rates of CS2 = 15sccm and C2H2= 500sccm. The total flow rate of the used gases was varied under the identical C2H2/CS2 flow rate ratio (33.3) condition. The C2H2 flow rate was manipulated under the identical CS2 flow rate (15sccm) condition. It was found that the formation and the alignment of carbon microcoils could be only achieved under the condition of 15sccm of CS2 flow rate in the range of 200 ~ 500sccm of C2H2 flow rate, regardless of the flow rate ratio of C2H2/CS2 and the total flow rate. The crystal structure of the well-aligned CMCs reveals the increase in the (002) peak in XRD spectrum for the aligned carbon microcoils, indicating the existence of the more regular structure in the aligned carbon microcoils. Based on these results, the cause for the formation of the aligned carbon microcoils only in the case of the CS2 flow rate = 15sccm with the imaginary pictures for the flow rate ratio of C2H2/CS2 just above the substrate were proposed.

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Plasma Enhanced Chemical Vapor Deposition of Silicon Sulfide and Phosphorus Sulfide thin Films

MRS Proceedings ◽

10.1557/proc-346-587 ◽

1994 ◽

Vol 346 ◽

Author(s):

R.K. Shibao ◽

V.I. Srdanov ◽

M. Hay ◽

H. Eckert

Keyword(s):

Thin Films ◽

Nuclear Magnetic Resonance ◽

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Rate Ratio ◽

Chemical Vapor ◽

Flow Rate Ratio ◽

Structural Studies ◽

Melt Quenching ◽

Quenching Method

ABSTRACTAmorphous SiSx:H (x ∼ 2) films have been synthesized from H2S and SiH4 precursors using a remote plasma enhanced chemical vapor deposition apparatus. Structural studies by solid state nuclear magnetic resonance (NMR) and Raman scattering reveal that the atomic environments in these materials are similar to those observed in melt-quenched silicon sulfide glasses, and are characterized by corner- and edge-shared SiS4/2 tetrahedra. Compared to these glasses, however, the films show consistently higher fractions of corner-sharing S1S4/2 tetrahedra. The ratio of corner- to edge sharing tetrahedra and the Si:S ratio can be influenced by the H2S/S1H4 flow rate ratio during deposition. Thus, PECVD opens up wider opportunities for structural tailoring of amorphous silicon sulfide materials than currently possible by means of the melt-quenching method. Preliminary data for the PECVD synthesis of phosphorus sulfide is also presented.

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Thin Oxynitride Films Prepared by Low Pressure Rapid Thermal Chemical Vapor Deposition

MRS Proceedings ◽

10.1557/proc-303-43 ◽

1993 ◽

Vol 303 ◽

Cited By ~ 1

Author(s):

P.K. Mclarty ◽

W.L. Hill ◽

X.L Xu ◽

J.J. Wortman ◽

G.S. Harris

Keyword(s):

Chemical Vapor Deposition ◽

Nitrogen Content ◽

Flow Rate ◽

Vapor Deposition ◽

Chemical Vapor ◽

Low Pressure ◽

Flow Rate Ratio ◽

Thermal Chemical Vapor Deposition ◽

Rate Ratios ◽

Post Deposition

ABSTRACTThin silicon oxynitride (Si-O-N) films have been deposited using low pressure rapid thermal chemical vapor deposition (RTCVD) with silane (SiH4), nitrous oxide (N2O), and ammonia (NH3) as the reactive gases. Structural analysis coupled with a study of deposition conditions indicate that an increase in NH3/N2O flow rate ratios leads to an increased N/O atomic ratio and a decreased Si-O-N deposition rate. Thin film (55-75A) polySi/Si-N-O/Si capacitors and transistors were fabricated for NH3/N2O flow rate ratios from 20% to 100%. Some of the films were subjected to a post deposition anneal at 950°C for 15 seconds in both argon and oxygen. Capacitance voltage measurements indicate a mid-gap interface trap density of ≤ 6 × 1010 eV−1cm−2 for all the films independent of both nitrogen content and post deposition annealing conditions. The transconductance was studied as a function of NH3/N2O flow rate ratio and decreasing peak gm values but improved high field degradation was observed for increased nitrogen content. This is consistent with previous work on nitrided oxides and suggests that the films are under tensile stress. Hot carrier stress at maximum substrate current was performed with the Si-O-N films displaying larger threshold voltage shifts when compared to furnace SiO2 indicating the possible existence of hydrogen related traps.

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