Heteroepitaxial Metal Oxides on Silicon by Laser Ablation

1990 ◽  
Vol 191 ◽  
Author(s):  
D. B. Fenner ◽  
D. K. Fork ◽  
G. A. N. Connell ◽  
J. B. Boyce ◽  
F. A. Ponce ◽  
...  

ABSTRACTThin epitaxial films of cubic - fluorite structured PrO2 and YSZ (yttria- stabilized zirconia) were grown on single crystal silicon substrates using the laser ablation - deposition technique. X-ray diffraction theta two - theta, omega rocking and phi scans indicate a high degree of epitaxial orientation of the films to the Si lattice. The highest quality of epitaxy was obtained with the PrO2 [111] oriented normal to Si(111) surfaces and the cubic YSZ [100] normal to Si(100) surfaces. For both PrO2 and YSZ, high epitaxial quality required the removal of the Si native oxide prior to deposition and careful control of the deposition environment. It was further found that the YSZ films on Si(100) were an excellent surface for subsequent laser ablation of YBCO films by the usual in situ process. The resistivity of this YBCO was ≈ 250 micro-ohm-cm at 300 K, extrapolated to the resistivity -temperature origin, showed a sharp transition to zero resistance at ≈ 85 K and was nearly identical to high quality YBCO films deposited on (bulk) YSZ substrates.

1997 ◽  
Vol 483 ◽  
Author(s):  
S. A. Ustin ◽  
C. Long ◽  
L. Lauhon ◽  
W. Ho

AbstractCubic SiC films have been grown on Si(001) and Si(111) substrates at temperatures between 600 °C and 900 °C with a single supersonic molecular beam source. Methylsilane (H3SiCH3) was used as the sole precursor with hydrogen and nitrogen as seeding gases. Optical reflectance was used to monitor in situ growth rate and macroscopic roughness. The growth rate of SiC was found to depend strongly on substrate orientation, methylsilane kinetic energy, and growth temperature. Growth rates were 1.5 to 2 times greater on Si(111) than on Si(001). The maximum growth rates achieved were 0.63 μm/hr on Si(111) and 0.375μm/hr on Si(001). Transmission electron diffraction (TED) and x-ray diffraction (XRD) were used for structural characterization. In-plane azimuthal (ø-) scans show that films on Si(001) have the correct 4-fold symmetry and that films on Si(111) have a 6-fold symmetry. The 6-fold symmetry indicates that stacking has occurred in two different sequences and double positioning boundaries have been formed. The minimum rocking curve width for SiC on Si(001) and Si(111) is 1.2°. Fourier Transform Infrared (FTIR) absorption was performed to discern the chemical bonding. Cross Sectional Transmission Electron Microscopy (XTEM) was used to image the SiC/Si interface.


2002 ◽  
Vol 750 ◽  
Author(s):  
M. J. Daniels ◽  
B. L. French ◽  
David King ◽  
J. C. Bilello

ABSTRACTQuasicrystalline precursor coatings were deposited on single crystal silicon and sapphire wafers by RF sputtering from an AlCuFe powder composite target. Synchrotron white beam radiography/topography and stress analysis were performed in situ on the wafers during heating to 495 or 585°C, and subsequent cooling. A plateau region of constant stress was present throughout most of the 1 hour anneals before a large tensile stress developed in the film during cooling due to coefficient of thermal expansion mismatch. Cracking was observed for films on both substrates at an average film stress of approximately 930 MPa. Distinct differences in the fracture behavior were observed for the two different substrates. X-ray diffraction performed on films after annealing suggested that texturing took place during the transition to a fully developed quasicrystalline structure.


2010 ◽  
Vol 25 (2) ◽  
pp. 149-153
Author(s):  
Isaac Vander ◽  
R. W. Zuneska ◽  
F. J. Cadieu

This paper presents a nondestructive measurement technique for the determination of the film thicknesses of Co and SmCo based magnetic films deposited by sputtering on single-crystal silicon (100) substrates. X-ray diffraction of Cu Kα radiation has been used to measure the intensity of the (400) reflection from bare silicon substrates and as attenuated by sputter coated Co and SmCo based films on Si substrates. A four-axis research diffractometer allowed the substrate orientation to be fine adjusted to maximize the (400) diffraction intensity. The thickness of SmCo based films was in a range from 0.05 to 5 μm. Co film thicknesses on Si could be measured to a few tens of nanometers. The accuracy of the thickness measurements depends on the effective mass attenuation coefficient of the film material. For the materials considered, the thicknesses determined by the X-ray attenuation method agree within at least several percent to values determined by other methods.


1996 ◽  
Vol 427 ◽  
Author(s):  
V. Svilan ◽  
K. P. Rodbell ◽  
L. A. Clevenger ◽  
C. Cabral ◽  
R. A. Roy ◽  
...  

AbstractPreferential crystal orientation of low-resistance C54 TiSi2 formed in the reaction of polycrystalline and single crystal silicon with titanium was investigated for Ti thicknesses ranging from 15 to 44 nm. Using in situ synchrotron x-ray diffraction during heating of 15 nm of Ti on single crystal Si, we observed that the C54 TiSi2 silicide film showed predominantly <040> grains oriented normal to the sample. In thicker silicide films the <311> orientation dominated or film was randomly oriented. An ex situ four circle diffractometer was used to investigate the strong <040> texture in narrow line arrays of C54-TiSi2 formed on polycrystalline silicon with linewidths from 0.2 to 1.1 μm. We observed that the angular distribution of <040> Ti Si2 grains is dependent on the line direction, where the majority of grains had their (100) planes oriented parallel with the line direction. These findings support a model of the C49 to C54 TiSi2 transformation involving rapid growth of certain orientations favored by the one-dimensional geometry imposed by narrow lines.


1994 ◽  
Vol 363 ◽  
Author(s):  
Y. W. Bae ◽  
W. Y. Lee ◽  
T. M. Besmann ◽  
P. J. Blau ◽  
L. Riester

AbstractThin films of titanium nitride were chemical vapor deposited on (100)-oriented single-crystal silicon substrates from tetrakis (dimethylamino) titanium, Ti((CH3)2N)4, and ammonia gas mixtures in a cold-wall reactor at 623 K and 655 Pa. The films were characterized by Auger electron spectroscopy, X-ray diffraction, and transmission electron spectroscopy. The nano-scale hardness of the film, measured by nanoindentation, was 12.7±0.6 GPa. The average kinetic friction coefficient against unlubricated, type- 440C stainless steel was determined using a computer-controlled friction microprobe to be ∼0.43.


1988 ◽  
Vol 129 ◽  
Author(s):  
J. P. West ◽  
C. B. Fleddermann

ABSTRACTThe use of a wide-area electron beam to aid the deposition of epitaxial silicon films has been studied. The electron beam used in this study is generated using a cold cathode, abnormal-glow discharge which allows a wide variation of electron energy and beam current. Depositions are performed on single crystal silicon substrates which are prepared using standard wet chemical silicon cleaning techniques and an in situ plasma etch using nitrogen tri-fluoride diluted in hydrogen. The beam diameter is approximately 10 cm and can readily be scaled up to accommodate larger diameters, allowing great potential for large area single wafer deposition. Using electron beams generated in this system, we have demonstrated enhanced growth rates and improved crystalline quality for films grown withelectronbeam enhancement.


Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.


1983 ◽  
Vol 23 ◽  
Author(s):  
Han-Sheng Lee

ABSTRACTN-channel MOS transistors were fabricated on silicon films that had been recrystallized by an argon ion laser at different power levels. These transistors showed electrical characteristics similar, but somewhat inferior to those devices fabricated on single crystal silicon substrates. These differences are attributed to the presence of trapping states at the grain boundaries of the crystallites in the recrystallized silicon. A coulombic scattering model is presented to explain these differences. In the case of films annealed at low laser power, an additional factor of nonuniform trap state distribution is invoked to explain device characteristics. This model provides an adequate explanation for the observed transport properties of transistors fabricated from recrystallized silicon films.


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