scholarly journals Surface Morphology and Microstructure of Al-O Alloys Grown by ECR Plasma Deposition

1995 ◽  
Vol 403 ◽  
Author(s):  
D. A. Marshall ◽  
J. C. Barbour ◽  
D. M. Follstaedt ◽  
A. J. Howard ◽  
R. J. Lad

AbstractThe growth of polycrystalline and amorphous aluminum-oxygen alloy films using electronbeam evaporation of Al in the presence of an O2 electron-cyclotron-resonance (ECR) plasma was investigated for film compositions varying from 40% Al (A12O3) to near 100% Al (A1Ox). Processing parameters such as deposition temperature and ion energy were varied to study their effects on surface texture and film microstructure. The Al-rich films (AlOx) contain polycrystalline fcc Al grains with finely dispersed second-phase particles of γ-A12O3 (1–2 nm in size). The surface roughness of these films was measured by atomic force microscopy and found to increase with sample bias and deposition temperature. Stoichiometric A12O3 films grown at 100°C and 400°C without an applied bias were amorphous, while an applied bias of -140 V formed a nanocrystalline γ-A12O3 film at 400°C. The surface roughness of the A12O3 increased with temperature while ion irradiation produced a smoother surface

1992 ◽  
Vol 242 ◽  
Author(s):  
R. K. Singh ◽  
D. Gilbert ◽  
R. Tellshow ◽  
R. Koba ◽  
R. Ochoa ◽  
...  

ABSTRACTWe have applied an electron cyclotron resonance technique to deposit diamond thin films on various substrates under remote plasma, low temperature (600°C) and low pressure (60 mTorr) conditions. Diamond films were grown on different substrates (silicon, molybdenum) with varying concentrations of precursor gases (methanol and water). A positive substrate bias (50 to 60 V) was found to be essential for the growth of diamond films onto substrates positioned 16 cm below the ECR plasma. The films were characterized by Raman, X-ray diffraction and scanning electron microscopy for microstructure, phase purity and chemical bonding characteristics. The effect of various processing parameters including gas pressure, gas composition, substrate temperature and bias have also been analyzed.


1999 ◽  
Vol 585 ◽  
Author(s):  
S. Matsuo ◽  
M. Yamamoto ◽  
T. Sadoh ◽  
T. Tsurushima ◽  
D. W. Gao ◽  
...  

AbstractEffects of ion-irradiation on oxidation of silicon at low temperatures (130°C) in an argon and oxygen mixed plasma excited by electron cyclotron resonance (ECR) interaction are investigated. First, dependence of energy and flux of incident ions on the flow rate and the microwave power is evaluated. It is shown that the flow rate and the microwave power are key parameters for controlling the energy and the flux of incident ions, respectively. Second, growth kinetics of the oxide films are studied. The growth rate depends on the energy and the flux of argon ions irradiated to the substrate, and the growth thickness increases proportionally to the root square of the oxidation time. Thus, the growth rate is limited by diffusion of oxidants enhanced by irradiation with argon ions. The effect of substrate bias on oxidation characteristics is also discussed. The electrical properties of the oxide films are improved by increasing the bias. The improvement is due to the reduction of damage at the surface of the substrate induced by the irradiation.


1991 ◽  
Vol 235 ◽  
Author(s):  
J. C. Barbour ◽  
H. J. Stein

ABSTRACTThe incorporation of hydrogen into silicon nitride films grown downstream from an electron cyclotron resonance (ECR) plasma decreased rapidly with increasing substrate temperature (100–600°C). Fourier transform infra-red (FTIR) spectroscopy showed that the hydrogen in the as-grown material was primarily bonded to nitrogen. However, an applied bias of -200 V caused an increase in the number of Si-H bonds relative to N-H bonds, as a result of increased ion-beam damage. In addition, ion irradiation of an as-grown film with 175 keV Ar+ at room temperature showed that H transferred from N-H bonds to Si-H bonds without a loss of H. Elastic recoil detection (ERD) and FTIR of thermally annealed films showed that the stability of H incorporated during deposition increased with deposition temperature, and that the N-H bond was more stable than the Si-H bond above 700°C. Deuterium plasma treatments, at 600°C, of annealed films caused isotopic substitution with a conservation of bonds. Therefore, hydrogen loss from annealed films is apparently accompanied by a reduction in dangling bonds.


1997 ◽  
Vol 495 ◽  
Author(s):  
N. Badi ◽  
A. Tempez ◽  
D. Starkov ◽  
N. Medelcr ◽  
A. Bensaoula ◽  
...  

ABSTRACTBoron nitride thin films on sapphire substrates were investigated for their tribological and optoelectronic applications. A gridless end Hall gun source and an electron cyclotron resonance (ECR) source were used for nitrogen species delivery while pure boron was evaporated at a rate of 0.2 Å/s. The surface stability of these thin films was investigated by high temperature annealing. Atomic force microscopy (AFM), friction force microscopy (FFM), and Knoop microhardness measurements were performed on the materials in order to assess their merits as tribological coatings. Finally, BN thin films were subjected to laser transient photoconductivity (TPC) experiments to determine both their optical laser damage threshold as well as their photoconductivity characteristics. For both single-pulse shot and multiple-pulse irradiation regimes, preliminary tests showed the higher the ion beam current used during growth (70–150 mA), the higher the optical damage threshold. The lower damage threshold was typical of BN films grown using an ECR plasma source and was measured to be in the range of ∼50 MW/cm2. Optical damage of films grown at ion beam currents above 100 mA was not observed at laser intensities up to few hundreds MW/cm2. A multiphoton excitation technique was utilized to obtain PC signals from this wide band gap material and preliminary results show that unusual PC voltage amplitudes as high as 0.5 V were observed.


1989 ◽  
Vol 165 ◽  
Author(s):  
Steven Dzioba

A UHV electron cyclotron resonance (ECR) plasma source has been used to deposit SiNx, SiOxNy and amorphous Si thin films on InP substrates for optoelectronic device applications. High quality dielectric films can be deposited at temperatures significantly lower than conventional techniques, namely less than 110°C. Selected applications pertinent to optoelectronic devices are used to establish the role of ion/electron fluxes in thin film properties.


2007 ◽  
Vol 353-358 ◽  
pp. 1867-1870 ◽  
Author(s):  
Xiao Long Weng ◽  
Wu Tang ◽  
Yu Tao Wu ◽  
Long Jiang Deng

Sn doped indium oxide (ITO) films were fabricated on polyethylene terephtalate (PET) substrate by magnetron sputtering at low deposition temperature using a 10 wt % SnO2-doped In2O3 target applied in the infrared regions as low emissivity materials. The microstructure and surface morphology of ITO films was studied using X-ray diffraction (XRD) and atomic force microscopy (AFM); the resistivity was investigated by four-point probe technology. It was found that the film with amorphous microstructure has highest resistivity to 1.956×10-3 2.cm at low deposition temperature and the surface roughness and resistivity increase with the increasing Ar sputtering pressure from 0.5Pa to 1.4Pa. The most interesting is that the resistivity increases with the increasing surface roughness, it indicates that there are internal correlation between roughness and resistivity.


1991 ◽  
Vol 236 ◽  
Author(s):  
J. C. Barbour ◽  
H. J. Stein

AbstractThe incorporation of hydrogen into silicon nitride films grown downstream from an electron cyclotron resonance (ECR) plasma decreased rapidly with increasing substrate temperature (100-600°C). Fourier transform infra-red (FTIR) spectroscopy showed that the hydrogen in the as-grown material was primarily bonded to nitrogen. However, an applied bias of -200 V caused an increase in the number of Si-H bonds relative to N-H bonds, as a result of increased ion-beam damage. In addition, ion irradiation of an asgrown film with 175 keV Ar+ at room temperature showed that H transferred from N-H bonds to Si-H bonds without a loss of H. Elastic recoil detection (ERD) and FTIR of thermally annealed films showed that the stability of H incorporated during deposition increased with deposition temperature, and that the N-H bond was more stable than the Si-H bond above 700°C. Deuterium plasma treatments, at 600°C, of annealed films caused isotopic substitution with a conservation of bonds. Therefore, hydrogen loss from annealed films is apparently accompanied by a reduction in dangling bonds.


2003 ◽  
Vol 762 ◽  
Author(s):  
William B. Jordan ◽  
Eric D. Carlson ◽  
Todd R. Johnson ◽  
Sigurd Wagner

AbstractThe structure of germanium thin films prepared on glass by plasma enhanced chemical vapor deposition was characterized by Raman spectroscopy, atomic force microscopy (AFM) and field emission scanning electron microscopy (SEM). Crystallinity, surface roughness, and grain size were measured as functions of film thickness and deposition temperature. Grain nucleation was apparent for films as thin as 10 nm. Over the thickness range studied, grain size increased with film thickness, whereas average surface roughness started to increase with film thickness, but then remained fairly constant at approximately 1 nm for a film thickness greater than 25 nm.


1995 ◽  
Vol 385 ◽  
Author(s):  
A. Weber ◽  
A. Dietz ◽  
R. Pöckelmann ◽  
C.-P. Klages

ABSTRACTA novel low temperature process for titanium nitride (TiN) deposition by means of an electron cyclotron resonance (ECR) plasma CVD process was applied to poly(tetrafluoroethylene) (PTFE). The organometallic compound tetrakis(dimethylamido)titanium (TDMAT) introduced into the downstream region of a nitrogen ECR plasma was used as a precursor for TiN deposition at 100°C.The thin TiN films (thickness 15-30 nm) act as interlayers to activate the electroless deposition of copper followed by an electroplating process. Prior to the deposition of the interlayer, the samples were treated on a biased susceptor with argon ions to enhance the adhesion of the TiN interlayer. This metallization procedure avoids the use of toxic and pollutive etching agents and yields adherent copper layers on PTFE.The maximum adhesion of the metal film on PTFE was established to be 13 N/mm2. As shown by atomic force microscopy (AFM), TiN grains were formed on the fluoropolymer surface. Film composition was investigated by secondary ionization mass spectrometry (SIMS).


2002 ◽  
Vol 16 (06n07) ◽  
pp. 1086-1090 ◽  
Author(s):  
Z. HASSAN ◽  
K. IBRAHIM ◽  
M. E. KORDESCH ◽  
W. HALVERSON ◽  
P. C. COLTER

The success of crystalline GaN as an optical and electronic material has motivated an enormous effort to explore all aspects of the material. Little is known and reported about the amorphous phase of this semiconducting wide band gap material. In this paper, we report on the properties of amorphous GaN (a-GaN) grown on p-Si at 443K using electron cyclotron resonance (ECR) plasma-assisted metalorganic chemical vapor deposition (MOCVD). Silicon is a potential alternative to sapphire due to its high quality and readily available as a large diameter and low cost substrates. The film was analyzed by a variety of methods, including scanning electron microscopy (SEM), atomic force microscopy (AFM) and x-ray diffraction (XRD). The current-voltage characteristics of a-GaN/Si heterojunction were measured from room temperature to 363K. Rectification behavior and photovoltaic effect were observed for this anisotype heterojunction. The electrical characteristics of Ni Schottky barriers on a-GaN were also investigated.


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