Films and Devices Deposited by Hwcvd at Ultra High Deposition Rates

2001 ◽  
Vol 664 ◽  
Author(s):  
A. H. Mahan ◽  
Y. Xu ◽  
E. Iwaniczko ◽  
D. L. Williamson ◽  
W. Beyer ◽  
...  
Keyword(s):  
Defect Density ◽  
State Of The Art ◽  
Chemical Vapor ◽  
Film Deposition ◽  
Hot Wire ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Film Deposition Rate ◽  
Staebler Wronski Effect

ABSTRACTThe structure of a-Si:H, deposited at rates in excess of 100Å/s by the hot wire chemical vapor deposition (HWCVD) technique, has been examined by x-ray diffraction (XRD), Raman spectroscopy, H evolution, and small-angle x-ray scattering (SAXS). As the film deposition rate (Rd) is increased, we find that the XRD, Raman and the H evolution peak curves are invariant with Rd, and exhibit structure consistent with state-of-the-art, compact a-Si:H films deposited at low Rd. The only exception is the SAXS signal, which increases by a factor of ∼100 over that for our best low Rd films. We relate changes in the film electronic structure (Urbach edge) to the increase in the SAXS signals. We also note the invariance of the saturated defect density versus Rd, and discuss possible reasons why the increase in the SAXS does not play a role in the Staebler-Wronski Effect for this type of material. Finally, device results are presented.

Stress in Hydrogenated Microcrystalline Silicon Thin Films

1999 ◽  
Vol 557 ◽  
Author(s):  
D. Peiró ◽  
C. Voz ◽  
J. Bertomeu ◽  
J. Andreu ◽  
E. Martínez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Vapor Deposition ◽  
Volume Fraction ◽  
Chemical Vapor ◽  
Hot Wire ◽  
X Ray Diffraction ◽  
Microcrystalline Silicon ◽  
X Ray ◽  
Silicon Thin Films ◽  
Abrupt Changes

AbstractHydrogenated microcrystalline silicon films have been obtained by hot-wire chemical vapor deposition (HWCVD) in a silane and hydrogen mixture at low pressure (<5 × 10-2 mbar). The structure of the samples and the residual stress were characterised by X- ray diffraction (XRD). Raman spectroscopy was used to estimate the volume fraction of the crystalline phase, which is in the range of 86 % to 98%. The stress values range between 150 and -140 MPa. The mechanical properties were studied by nanoindentation. Unlike monocrystalline wafers, there is no evidence of abrupt changes in the force-penetration plot, which have been attributed to a pressure-induced phase transition. The hardness was 12.5 GPa for the best samples, which is close to that obtained for silicon wafers.

scholarly journals Correlation of Electrical Properties With Defects in A Homoepitaxial Chemical-Vapor-Deposited Diamond

1995 ◽  
Vol 416 ◽  
Author(s):  
S. Han ◽  
G. Rodriguez ◽  
A. Taylori ◽  
M. A. Plano ◽  
M. D. Moyer ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Diamond Film ◽  
Carrier Transport ◽  
Defect Density ◽  
Chemical Vapor ◽  
Hole Mobility ◽  
Limiting Factor ◽  
X Ray Diffraction ◽  
Density Region ◽  
X Ray

ABSTRACTA high-quality, low-stress 200 gim epitaxial diamond film has been grown on a 400 μm thick high-temperature-high-pressure Ila diamond. X-ray diffraction images of the film indicate that a large region of the film is fairly defect free and individual dislocations have been imaged in this region. Depth-resolved Raman results indicate that the region of the film with a low density of defects also has lower stress than in the higher defect density region. Transient photoconductivity measurements were performed on the high and low line defect density regions of the homoepitaxial diamond film to determine the effects of the stress and defect density on the combined electron-hole mobility and carrier lifetime. The correlation between the electrical properties and the x-ray diffraction imaging suggests that line defects may not be the limiting factor in the carrier transport at the present film quality

The Effect of H2 Dilution On Thin Film SiN Deposited by Hot Wire Cvd Using SiH4 and NH3 Gas Mixtures

2001 ◽  
Vol 664 ◽  
Author(s):  
A. C. Dillon ◽  
L. Gedvillas ◽  
D. L. Williamson ◽  
J. Thiesen ◽  
J. D. Perkins ◽  
...  
Keyword(s):  
Thin Film ◽  
Gas Phase ◽  
Chemical Vapor ◽  
Structural Disorder ◽  
Gas Mixtures ◽  
Film Structure ◽  
Hot Wire ◽  
X Ray Diffraction ◽  
X Ray ◽  
N Incorporation

ABSTRACTThe structure of thin film SiN, deposited by the hot wire chemical vapor deposition (HWCVD) technique using SiH4 and NH3 gas mixtures, has been examined as a function of the amount of H2 dilution of the gas mixture. For NH3/SiH4 gas ratios > 0.5/1, all films are a-SiN:H. While H2 dilution does not change the basic film structure, in that the films are amorphous with all dilutions, H2 dilution does increase the efficiency of NH3 dissociation in the gas phase, and causes a further reduction in the already small amount of N-H bonding in a-SiN:H films deposited by HWCVD. For NH3/SiH4 gas ratios typically <0.5/1 and with high H2 dilution, the first deposition of µc-SiN is demonstrated. X-ray diffraction (XRD) measurements demonstrate that the structure of these films consists of silicon crystallites embedded in an a-SiN:H matrix. An upper limit for N incorporation with the preservation of microcrystallinity was found, beyond which the films again became amorphous. The existence of this limit is explained in terms of structural disorder in the a-SiN:H tissue brought about by N incorporation.

scholarly journals Metal film deposition by laser breakdown chemical vapor deposition

1986 ◽  
Vol 1 (3) ◽  
pp. 420-424 ◽  
Author(s):  
T.R. Jervis ◽  
L.R. Newkirk
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Film Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Dielectric breakdown of gas mixtures can be used to deposit thin films by chemical vapor deposition with appropriate control of flow and pressure conditions to suppress gas-phase nucleation and particle formation. Using a pulsed CO2 laser operating at 10.6 μ where there is no significant resonant absorption in any of the source gases, homogeneous films from several gas-phase precursors have been sucessfully deposited by gas-phase laser pyrolysis. Nickel and molybdenum from the respective carbonyls representing decomposition chemistry and tungsten from the hexafluoride representing reduction chemistry have been demonstrated. In each case the gas precursor is buffered with argon to reduce the partial pressure of the reactants and to induce breakdown. Films have been characterized by Auger electron spectroscopy, x-ray diffraction, transmission electron microscopy, pull tests, and resistivity measurements. The highest quality films have resulted from the nickel depositions. Detailed x-ray diffraction analysis of these films yields a very small domain size consistent with the low temperature of the substrate and the formation of metastable nickel carbide. Transmission electron microscopy supports this analysis.

Deposition of Device Quality, Low H Content a-Si:H by the Hot Wire Technique

1991 ◽  
Vol 219 ◽  
Author(s):  
A. H. Mahan ◽  
B. P. Nelson ◽  
S. Salamon ◽  
R. S. Crandall
Keyword(s):  
Chemical Vapor ◽  
Hot Wire ◽  
X Ray ◽  
Quality Properties ◽  
X Ray Scattering ◽  
Structural Differences ◽  
Rf Glow Discharge ◽  
First Time ◽  
Hydrogenated Amorphous ◽  
Traditional Manner

ABSTRACTWe report measurements of the Urbach edge, optical bandgap, and ambipolar diffusion length on a series of hydrogenated amorphous silicon (a-Si:H) films deposited by hot-wire-assisted chemical vapor deposition (HW). We compare the properties of these films to those of a series of a-Si:H films deposited by the traditional radio frequency (rf) glow discharge (GD) technique, where we varied the substrate temperature to change the bonded H content (CH). We show for the first time that, as CH is decreased below the value traditionally associated with device quality GD a-Si:H (∼10 at.%), the electronic properties of the GD films deteriorate in the traditional manner while those for the HW samples remain device quality. Properties of these low CH HW samples will be presented and compared to those of GD films containing comparable CH. Because several indications exist that the structure of the HW films is different than that of the GD films, Raman and Small Angle X-Ray Scattering (SAXS) measurements are presented to illustrate structural differences.

Observation of Improved Structural Ordering in Low H Content, Hot wire Deposited a-Si:H

1997 ◽  
Vol 467 ◽  
Author(s):  
A. H. Mahan ◽  
D. L. Williamson ◽  
T. E. Furtak
Keyword(s):  
Substrate Temperature ◽  
Phonon Mode ◽  
Bond Angle ◽  
Hot Wire ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angle Deviation ◽  
Medium Range ◽  
Staebler Wronski Effect ◽  
Annealing Experiments

ABSTRACTWe present the results of X-ray diffraction measurements on a series of device quality hot wire (HW) deposited a-Si:H films in which we vary only the substrate temperature of the growing film, which decreases the bonded film H content in a systematic fashion. By increasing the substrate temperature to ∼375°C, where we deposit our low H content (CH) HW films which exhibit a reduced Staebler-Wronski effect, the width of the first peak in the X-ray diffraction pattern narrows noticeably. We interpret this narrowing to be the first indication of improved medium range ordering in our low CH, device quality HW a-Si:H. We note in addition that measurements of the bond angle deviation, obtained from Raman measurements of the half width of the Si-Si TO phonon mode on the same samples, do not show this same evidence of improved ordering as the substrate temperature is increased. We discuss these differences in the context of sample annealing experiments designed to effuse H from the region of the sample probed by the surface sensitive Raman technique, while leaving the bulk of the material, which is sampled by the X-ray beam, largely unaffected.

X-Ray Diffraction Analysis Of Strain And Mosaic Structure In (001) Oriented Homoepitaxial Diamond Films

1996 ◽  
Vol 423 ◽  
Author(s):  
W. Brock Alexander ◽  
Pehr E. Pehrsson ◽  
David Black ◽  
James E. Butler
Keyword(s):  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Lattice Parameter ◽  
Film Deposition ◽  
Mosaic Structure ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
High Pressure High Temperature

AbstractHomoepitaxial diamond films were grown on (001) oriented high pressure, high temperature type lb diamond by microwave plasma-assisted chemical vapor deposition to thicknesses of 27–48 μm. Substrates were polished off-axis 5.5° ±0.5° in the [100] direction prior to film deposition. Some of the diamond films developed tensile stress sufficiently large to result in cracking on { 111 } cleavage planes, while other films exhibited compressive stress. The strain and mosaic structure were measured with seven crystal x-ray diffraction. This characterization tool allowed the separation of misorientation effects from those of lattice parameter variation. Films exhibited smaller (˜88 ppm) and larger (˜27 ppm) perpendicular lattice parameters relative to the HPHT substrates. A cross-sectional approach for probing strain in diamond films with micro-Raman analysis was used to show stress distributions (˜100–300 MPa) through the thickness of the film.

New Structure of CTAB Templated Silica Films as revealed by GISAXS coupled to HRTEM

2000 ◽  
Vol 628 ◽  
Author(s):  
Sophie Besson ◽  
Catherine Jacquiod ◽  
Thierry Gacoin ◽  
André Naudon ◽  
Christian Ricolleau ◽  
...  
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Grazing Incidence ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
Silica Films ◽  
X Ray ◽  
X Ray Scattering ◽  
Hexagonal Arrangement ◽  
Spherical Micelles

ABSTRACTA microstructural study on surfactant templated silica films is performed by coupling traditional X-Ray Diffraction (XRD) and Transmission Electronic Microscopy (TEM) to Grazing Incidence Small Angle X-Ray Scattering (GISAXS). By this method it is shown that spin-coating of silicate solutions with cationic surfactant cetyltrimethylammonium bromide (CTAB) as a templating agent provides 3D hexagonal structure (space group P63/mmc) that is no longer compatible with the often described hexagonal arrangement of tubular micelles but rather with an hexagonal arrangement of spherical micelles. The extent of the hexagonal ordering and the texture can be optimized in films by varying the composition of the solution.

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