Semiconductor Thin Films Grown by Laser Photolysis

1982 ◽  
Vol 17 ◽  
Author(s):  
J.G. Eden ◽  
J.E. Greene ◽  
J.F. Osmundsen ◽  
D. Lubben ◽  
C.C. Abele ◽  
...  
Keyword(s):  
Activation Energy ◽  
Growth Rate ◽  
Vapor Deposition ◽  
Film Growth ◽  
Single Photon ◽  
Chemical Vapor ◽  
Intensity Dependence ◽  
Grain Sizes ◽  
Semiconductor Thin Films ◽  
Si Films

ABSTRACTThin (< 1.2 μpm) Ge and Si films have been grown with rates up to 3.6 μm/hr by laser-induced chemical vapor deposition (LCVD) on a variety of substrates. Germanium films grown on amorphous SiO2 (quartz) by photodissociating GeH4 in He at 248 nm (KrF laser) exhibit grain sizes of 0.3 – 0.5 μm that increase only slightly up to the pryolytic threshold for GeH4 (280°C). On (100) NaCl, however, Ge films grown at a substrate temperature of 120°C are expitaxial. The activation energy for the LCVD growth of Ge films (from GeH4) on SiO2 is measured to be 85 ± 20 meV which suggests that germanium is arriving at the substrate in atomic form. The wavelength and intensity dependence of the initial film growth rate supports the conclusion that this process is photolytic and is initiated by the absorption of a single photon.

Deposition and Crystallisation Behaviour of Amorphous Silicon Thin Films Obtained by Pyrolysis of Disilane Gas at Very Low Pressure

1994 ◽  
Vol 345 ◽  
Author(s):  
T. Kretz ◽  
D. Pribat ◽  
P. Legagneux ◽  
F. Plais ◽  
O. Huet ◽  
...  
Keyword(s):  
Activation Energy ◽  
Growth Rate ◽  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Electrical Conductance ◽  
Chemical Vapor ◽  
Crystalline Fraction ◽  
Silicon Thin Films ◽  
Crystallisation Behaviour

AbstractHigh purity amorphous silicon layers were obtained by ultrahigh vacuum (millitorr range) chemical vapor deposition (UHVCVD) from disilane gas. The crystalline fraction of the films was monitored by in situ electrical conductance measurements performed during isothermal annealings. The experimental conductance curves were fitted with an analytical expression, from which the characteristic crystallisation time, tc, was extracted. Using the activation energy for the growth rate extracted from our previous work, we were able to determine the activation energy for the nucleation rate for the analysed-films. For the films including small crystallites we have obtained En ∼ 2.8 eV, compared to En ∼ 3.7 eV for the completely amorphous ones.

Low pressure chemical vapor deposition of B-N-C-H films from triethylamine borane complex

1995 ◽  
Vol 10 (2) ◽  
pp. 320-327 ◽  
Author(s):  
R.A. Levy ◽  
E. Mastromatteo ◽  
J.M. Grow ◽  
V. Paturi ◽  
W.P. Kuo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Apparent Activation Energy ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Index Of Refraction ◽  
Arrhenius Behavior ◽  
Pressure Chemical

In this study, films consisting of B-N-C-H have been synthesized by low pressure chemical vapor deposition using the liquid precursor triethylamine borane complex (TEAB) both with and without ammonia. When no NH3 is present, the growth rate was observed to follow an Arrhenius behavior in the temperature range of 600 to 800 °C with an apparent activation energy of 11 kcal/mol. A linear dependence of growth rate is observed as a function of square root of flow rate for the TEAB range of 20 to 60 sccm, indicating that the reaction rate is controlled by the adsorption of borane. The addition of NH3 to TEAB had the effect of lowering the deposition temperature down to 300 °C and increasing the apparent activation energy to 22 kcal/mol. Above 650 °C, the carbon concentration of the deposits increased significantly, reflecting the breakup of the amine molecule. X-ray diffraction measurements indicated the films to be in all cases amorphous. Infrared spectra of the films showed absorption peaks representing the vibrational modes of B-N, B-N-B, B-H, and N-H. The index of refraction varied between 1.76 and 2.47, depending on composition of the films. Films deposited with no NH3 above 700 °C were seen to be compressive while films below that temperature were tensile. In the range of 350 to 475 °C, the addition of NH3 to TEAB resulted in films that were mildly tensile, while below 325 °C and above 550 °C, the films were found to be compressive. Both the hardness and Young's modulus of the films decreased with higher temperatures, reflecting the influence of the carbon presence.

On the optimization of a dc arcjet diamond chemical vapor deposition reactor

1996 ◽  
Vol 11 (3) ◽  
pp. 694-702 ◽  
Author(s):  
S. W. Reeve ◽  
W. A. Weimer ◽  
D. S. Dandy
Keyword(s):  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Methyl Radical ◽  
Chemical Kinetic Model ◽  
Model Calculations ◽  
Chemical Vapor Deposition Reactor

Based on results from chemical kinetic model calculations, a method to improve diamond film growth in a dc arcjet chemical vapor deposition reactor has been developed. Introducing the carbon source gas (CH4) into an Ar/H2 plasma in close proximity to the substrate produced diamond films exhibiting simultaneous improvements in quality and mass deposition rates. These improvements result from a reduced residence time of the methane in the plasma which inhibits the hydrocarbon chemistry in the gas from proceeding significantly beyond methyl radical production prior to encountering the substrate. Improvements in growth rate were modest, increasing by only a factor of two. Optical emission actinometry measurements indicate that the flux of atomic hydrogen across the stagnation layer to the substrate is mass diffusion limited. Since diamond growth depends upon the flux of atomic H to the substrate, these results suggest that under the conditions examined here, a low atomic H flux to the substrate poses an upper limit on the attainable diamond growth rate.

Grain size, Grain Uniformity, and (111) Texture Enhancement by Solid-phase Crystallization of F- and C-implanted SiGe Films

2000 ◽  
Vol 15 (7) ◽  
pp. 1630-1634 ◽  
Author(s):  
A. Rodríguez ◽  
J. Olivares ◽  
C. González ◽  
J. Sangrador ◽  
T. Rodríguez ◽  
...  
Keyword(s):  
Grain Size ◽  
Vapor Deposition ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Solid Phase Crystallization ◽  
Grain Sizes ◽  
Pressure Chemical ◽  
Film Microstructure ◽  
Si Films ◽  
Size Dispersion

The crystallization kinetics and film microstructure of poly-SiGe layers obtained by solid-phase crystallization of unimplanted and C- and F-implanted 100-nm-thick amorphous SiGe films deposited by low-pressure chemical vapor deposition on thermally oxidized Si wafers were studied. After crystallization, the F- and C-implanted SiGe films showed larger grain sizes, both in-plane and perpendicular to the surface of the sample, than the unimplanted SiGe films. Also, the (111) texture was strongly enhanced when compared to the unimplanted SiGe or Si films. The crystallized F-implanted SiGe samples showed the dendrite-shaped grains characteristic of solid-phase crystallized pure Si. The structure of the unimplanted SiGe and C-implanted SiGe samples consisted of a mixture of grains with well-defined contour and a small number of quasi-dendritic grains. These samples also showed a very low grain-size dispersion.

Deposition of YSZ Thin Films by Liquid Fuel Combustion Chemical Vapor Deposition

2002 ◽  
Author(s):  
Zhigang Xu ◽  
Jag Sankar ◽  
Qiuming Wei ◽  
Jim Lua ◽  
Sergey Yamolenko ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Substrate Temperature ◽  
Vapor Deposition ◽  
Liquid Fuel ◽  
Film Growth ◽  
Early Stage ◽  
Chemical Vapor ◽  
Nucleation Density

Thin film of YSZ electrolyte is highly desired to reduce the electrical resistance in SOFCs. YSZ thin Films have been successfully produced using liquid fuel combustion chemical vapor deposition (CCVD) technique. Nucleation of the YSZ particles were investigated based on two processing parameters, i.e., substrate temperature and total-metal-concentration in the liquid fuel. An optimum substrate temperature was found for highest the nucleation density. The nucleation density was increased with the total-metal-concentration. Microstructure evolution of the YSZ particles in the early stage in film growth was also studied. It was found that the particle growth rate was linear with processing time, and the particle orientation was varying with the time in the early stage of the film processing. To enhance the film growth rate, the effect of thermophoresis was studied. By increase the temperature gradient towards substrate, the effect of thermophoresis was enhanced and the film growth is also increased.

The Reaction of NH3 With TiN: Implications for CVD

1995 ◽  
Vol 410 ◽  
Author(s):  
Michelle T. Schulberg ◽  
Mark D. Allendorf ◽  
Duane A. Outka
Keyword(s):  
Activation Energy ◽  
Chemical Vapor Deposition ◽  
Reaction Temperature ◽  
Vapor Deposition ◽  
High Probability ◽  
Film Growth ◽  
Chemical Vapor ◽  
Temperature Programmed Desorption ◽  
Surface Sites ◽  
Temperature Programmed

ABSTRACTSince NH3 is an important component of TiN chemical vapor deposition (CVD) processes, understanding the NH3/TiN surface interaction is crucial to developing a model for the overall reaction. Temperature programmed desorption experiments show that NH3 adsorbs molecularly on amorphous TiN surfaces. Chemisorption occurs at only ∼5% of the surface sites, with an activation energy for desorption of 24 kcal/mol. The sticking probability into this state is 0.06 at 100 K. In addition, NH3 adsorbs with high probability into a multilayer state with an activation energy for desorption of 7.3 kcal/mol, similar to that found in other systems. NH3 does not dissociate on TiN. Under CVD conditions, however, the reactivity of NH3 on TiN may increase and surface reactions may play a part in film growth.

Large grain polycrystalline silicon via chemical vapor deposition

1999 ◽  
Vol 14 (3) ◽  
pp. 672-681 ◽  
Author(s):  
Bruce N. Beckloff ◽  
W. Jack Lackey ◽  
Elliott M. Pickering
Keyword(s):  
Grain Size ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Process Variable ◽  
Dominant Effect ◽  
System A ◽  
B Doping ◽  
Si Films

Large grain polycrystalline Si films were grown by chemical vapor deposition (CVD) onto TiB2 substrates using the SiCl4–H2 reagent system. A statistically designed processing study was used to correlate the film growth rate, crystallographic orientation, and grain size with deposition temperature, the SiCl4 : H2 ratio, and the level of B doping. Each process variable influenced grain size with temperature having the dominant effect. Grains as large as 15 to 20 μm were achieved for a coating thickness of about 50 μm.

c-axis lithium niobate thin film growth on silicon using solid-source metalorganic chemical vapor deposition

1999 ◽  
Vol 14 (6) ◽  
pp. 2662-2667 ◽  
Author(s):  
S. Y. Lee ◽  
R. S. Feigelson
Keyword(s):  
Growth Rate ◽  
Surface Roughness ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Optimal Growth ◽  
Optical Losses ◽  
Metalorganic Chemical

Textured c-axis oriented LiNbO3 films have been grown for waveguiding applications on silicon substrates by the solid-source metalorganic chemical vapor deposition (MOCVD) method using tetramethylheptanedionate sources. Thermally grown SiO2 layers were used as cladding layers to provide optical confinement in the LiNbO3 films. The texture direction could be varied from the [006] to the [012] direction by either increasing the growth temperature and/or decreasing the growth rate. Under optimal growth conditions, 100% [006] texturing could be achieved without the aid of an electric field or by using a SiNx buffer layer. The crystallinity and surface rms roughness of c-axis oriented films were found to be strongly dependent on the growth rate. Rocking curve full-width half-maximum (FWHM) values of (006) peaks could be decreased to less than 2° by increasing the growth rate. The surface roughness also decreased with growth rate, and rms values as low as 1.5 nm were achieved. On the other hand, too high a growth rate leads to increased roughness due to gas phase nucleation. The optical losses were closely correlated with surface roughness, and the best films had optical losses near 4.5 dB/cm at a wavelength of 632.8 nm.

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