Heteroepitaxial Si-ZrO2-Si by MOCVD

1993 ◽  
Vol 335 ◽  
Author(s):  
Anton C. Greenwald ◽  
Nader M. Kalkhoran ◽  
Fereydoon Namavar ◽  
Alain E. Kaloyeros ◽  
Ioannis Stathakos

AbstractThe objective of this research was to demonstrate heteroepitaxial growth of yttria stabilized cubic zirconia on single crystal silicon substrates by chemical vapor deposition (CVD) using metalorganic source materials. We succeeded in depositing extremely smooth, well aligned films of zirconia on silicon substrates, both the <100> and <111> orientations, without an oxide interfacial layer. Experimental variables investigated included varying zirconia source materials, substrate temperatures, oxygen concentration, gas flow rates, yttria doping, substrate orientation, and cobalt-silicide as an oxygen diffusion barrier. ZrO2 films were predominantly tetragonal when deposited in the absence of oxygen while cubic phase material could be put down at 750°C with oxygen background. Films deposited from TMHD zirconium contained no measurable carbon contamination. Deposits from trifluoro-acetylacetonate Zr contained small amounts of fluorine, even in the presence of water vapor, and some carbon when hydrogen was used as a diluent gas.

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.


2006 ◽  
Vol 20 (25n27) ◽  
pp. 4213-4218 ◽  
Author(s):  
SEUNG BAEK ◽  
CHANG-SUNG SEOK

In this study, using the nano and micro-indentation tests and finite element analysis (FEA), we investigated the fracture behaviors of diamond like carbon (DLC) on silicon in indentation state. Diamond like carbon coating of 3μm and 1.5μm thickness were deposited on polished (100) single crystal silicon substrates by radio frequency plasma assisted chemical vapor deposition (RF-PACVD), respectively. Fracture toughness of DLC films was calculated from the measured lengths of the cracks formed by nano and micro-indentation on each sample. We used various equations such as Lawn's and Liang's equation to calculate the fracture toughness. The effective fracture toughnesses of these DLC films were 1.2 ~1.3 MPam 0.5, calculated by Lawn's and Liang's equations. The true fracture toughness of DLC on silicon, excluding the portion of fracture toughness due to a substrate, was determined to be 4.0~5.1 MPam 0.5. DLC films with crack initiation and propagation were analyzed by finite element method.


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.


1981 ◽  
Vol 10 ◽  
Author(s):  
T. Asano ◽  
H. Ishiwara

Heteroepitaxial CaF2/Si and Si/CaF2/Si structures were prepared by conventional vacuum evaporation of CaF2 and silicon onto silicon substrates. The optimum conditions for obtaining good epitaxial films were investigated by changing the silicon substrate orientation, the film thickness and the substrate temperature during film deposition. From Rutherford backscattering and channelling spectroscopy it was found that CaF2 films with excellent film quality were obtained on Si(111), Si(110) and Si(100) substrates at substrate temperatures of 600– 800°C, 800°C and 500–600°C respectively. It was also found from Rutherford backscattering and channelling spectroscopy and from transmission electron microscopy that single-crystal silicon films are formed on a CaF2/Si(111) structure at a substrate temperature of 700°C. From measurements of the electrical properties of the top silicon film after the implantation of phosphorus ions at 2 ×1015 cm−2 and subsequent annealing at 750°C, an electron Hall mobility of 69cm2 V−1 s−1 was obtained.


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.


2018 ◽  
Vol 281 ◽  
pp. 22-27
Author(s):  
Zhao Chen ◽  
Rong Zheng Liu ◽  
Jia Xing Chang ◽  
Ma Lin Liu

Accident Tolerant fuel (ATF) concept was put forward after the Fukushima accident. Among different kinds of ATF, Fully Ceramic Microencapsulated Fuels (FCM) have been paid more and more attention in recent years. SiC matrix is one of the important constituent parts in FCM fuel system, which is sintered from kinds of SiC powders. In this study, SiC nanoparticles were prepared by Fluidized Bed Chemical Vapor Deposition (FB-CVD) method using Hexamethyldisilane (HMDS) as precursor, aimed at reducing the sintering temperature and pressure of FCM-SiC matrix. Experiments of different temperatures with different argon gas ratios were carried out. It was found that good crystal SiC could be obtained from 850°C to 1250°C, under pure hydrogen or H2: Ar=15:1. Different H2 carrier gas flow rate tests were also conducted. With the increase of hydrogen flow rates, the SiC was transformed from 3C-SiC to other types, such as 6H or 15R, but no significant effect was found on particle shape. Based on the characterizations of XRD, SEM and TEM, the results showed the spherical SiC nanoparticles could be obtained as well as 20 nanometers in diameter at the condition of 1150°C, H2: Ar=15:1, under different hydrogen flow rates. Different hydrogen flow rates had little influence on the particle size of SiC nanoparticles.


1989 ◽  
Vol 158 ◽  
Author(s):  
M. Jubber ◽  
J.I.B. Wilson ◽  
J.L. Davidson ◽  
P. John ◽  
P.G. Roberts

ABSTRACTGold tracks have been deposited on thermally oxidised and single crystal silicon, gold and nichrome coated silicon wafers by pyrolytic decomposition of gaseous alkyl (triethyl phosphine) gold(I) complexes using focussed 514 nm radiation from an argon ion laser. The precursors, RAu(I)Et3P, R = CH3, C2H5 are low melting point crystalline solids with relatively high vapour pressures (∼5 mtorr). They are representative of a class of compounds being evaluated for laser deposition of gold. Differential scanning calorimetry, DSC, shows that the thermal decomposition of MeAu(I)Et3P in the solid state is a two-stage process. The decomposition temperature is 63 ± 1°C. Tracks were deposited at laser scan speeds up to 35 μm s−1 with a beam diameter (1/e2) at the focus of ∼12 μm. SIMS, EDX and laser ionisation microprobe analysis, LIMA, were used to determine the chemical composition of the tracks. The purity of >98% is consistent with the measured resistivities (4.2 μΩ cm) at room temperature compared to bulk gold (∼2 μΩ cm). These resistivities were achieved without post deposition annealing. Stylus profilimetry and SEM data showed the lines produced from MeAu(I)Et3P have a virtually rectangular cross-section. Together with the absence of the ubiquitous λ-ripples, this feature suggests that deposition is more rapid on the gold surface than on the SiO2 substrate. Laser power thresholds are lower for silicon substrates coated with thin (5 - 10°A) films of gold or nichrome.


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