Morphological Instability of a Sic Film During Carbonization

1996 ◽  
Vol 436 ◽  
Author(s):  
C.-H. Chiu ◽  
L. B. Freund

AbstractA model is developed to understand the morphological stability of a SiC film on a Si substrate during carbonization where the Si substrate is exposed to a carbon precursor. The morphological stability is determined by considering the surface evolution along a slightly wavy film surface and film-substrate interface. The morphological evolution along the film surface is dominated by surface diffusion and along the interface by a chemical reaction. The kinetic analysis shows the stability is controlled by the film surface energy, the interface energy, the diffusion-reaction process of the carbon precursor, and the strain energy. At small wavelengths of the surface profiles, the two types of surface energy dominate, which results in stable morphology. The diffusion-reaction process dictates the surface stability at large wavelengths. The strain energy may cause the surfaces to become unstable at moderate wavelengths; the instability can be completely suppressed by the diffusion-reaction process and the film surface energy, while it is enhanced by a large value of interface energy.

2008 ◽  
Vol 600-603 ◽  
pp. 251-254 ◽  
Author(s):  
Yong Mei Zhao ◽  
Guo Sheng Sun ◽  
Xing Fang Liu ◽  
Jia Ye Li ◽  
Wan Shun Zhao ◽  
...  

Using AlN as a buffer layer, 3C-SiC film has been grown on Si substrate by low pressure chemical vapor deposition (LPCVD). Firstly growth of AlN thin films on Si substrates under varied V/III ratios at 1100oC was investigated and the (002) preferred orientational growth with good crystallinity was obtained at the V/III ratio of 10000. Annealing at 1300oC indicated the surface morphology and crystallinity stability of AlN film. Secondly the 3C-SiC film was grown on Si substrate with AlN buffer layer. Compared to that without AlN buffer layer, the crystal quality of the 3C-SiC film was improved on the AlN/Si substrate, characterized by X-ray diffraction (XRD) and Raman measurements.


2011 ◽  
Vol 409 ◽  
pp. 597-602
Author(s):  
Yuichi Mizuno ◽  
Kenji Okushiro ◽  
Yoshiyuki Saito

Grain boundary migration in materials under severe plastic deformation was simulated by the phase field methods. The interface energy and dislocation density on growth kinetics were simulated on systems of 2-dimensional lattice. .In inhomogeneous systems grain size distributions in simulated grain structures were binodal distributions. The classification of the solution of differential equations based on the mean-field Hillert model describing temporal evolution of the scaled grain size distribution function was in good agreement with those given by the Computer simulations. Effect of dislocation on thermodynamic stability was taken into consideration. Dislocation density distribution was calculated by a equation based on the diffusion-reaction equation.. Scaled grain size distribution was known to be affected by the dislocation.


2012 ◽  
Vol 472-475 ◽  
pp. 1451-1454
Author(s):  
Xue Hui Wang ◽  
Wu Tang ◽  
Ji Jun Yang

The porous Cu film was deposited on soft PVDF substrate by magnetron sputtering at different sputtering pressure. The microstructure and electrical properties of Cu films were investigated as a function of sputtering pressure by X-ray diffraction XRD and Hall effect method. The results show that the surface morphology of Cu film is porous, and the XRD revealed that there are Cu diffraction peaks with highly textured having a Cu-(220) or a mixture of Cu-(111) and Cu-(220) at sputtering pressure 0.5 Pa. The electrical properties are also severely influenced by sputtering pressure, the resistivity of the porous Cu film is much larger than that fabricated on Si substrate. Furthermore, the resistivity increases simultaneously with the increasing of Cu film surface aperture, but the resistivity of Cu film still decreases with the increasing grain size. It can be concluded that the crystal structure is still the most important factor for the porous Cu film resistivity.


1996 ◽  
Vol 436 ◽  
Author(s):  
R. P. Vinci ◽  
J. C. Bravman

AbstractWe have modeled the effects of grain aspect ratio on strain energy density in (100)-oriented grains in a (111)-textured Cu film on a Si substrate. Minimization of surface energy, interface energy, and strain energy density (SED) drives preferential growth of grains of certain crystallographic orientations in thin films. Under conditions in which the SED driving force exceeds the surface- and interface-energy driving forces, Cu films develop abnormally large (100) oriented grains during annealing. In the elastic regime the SED differences between the (100) grains and the film average arise from elastic anisotropy. Previous analyses indicate that several factors (e.g. elimination of grain boundaries during grain growth) may alter the magnitude of the SED driving force. We demonstrate, using finite element modeling of a single columnar (100) grain in a (111) film, that changes in grain aspect ratio can significantly affect the SED driving force. A minimum SED driving force is found for (100) Cu grains with diameters on the order of the film thickness. In the absence of other stagnation mechanisms, such behavior could cause small grains to grow abnormally and then stagnate while large grains continue to grow. This would lead to a bimodal grain size distribution in the (100) grains preferred by the SED minimization.


2011 ◽  
Vol 276 ◽  
pp. 21-25
Author(s):  
S.O. Gordienko ◽  
A. Nazarov ◽  
A.V. Rusavsky ◽  
A.V. Vasin ◽  
N. Rymarenko ◽  
...  

This paper presents an analysis of the electrical characteristics of the amorphous silicon carbide films deposited on the SiO2/Si substrate. Aspects of RF plasma treatment on electrical and structural characteristics of a-SiC film are discussed. It is demonstrated that the dominant mechanism of current transport in the a-SiC thin film is determined by variable-range hopping conductivity at the Fermi level. Studies of the a-SiC film at temperatures from 300 K to 600 K also indicate that silicon carbide is a perspective material for fabrication of temperature sensor.


2013 ◽  
Vol 745-746 ◽  
pp. 131-135
Author(s):  
Hu Rui Yan ◽  
Nuo Fan Ding ◽  
Gang Wu ◽  
Ping Xiong Yang ◽  
Jun Hao Chu ◽  
...  

In the process of BiFeO3 film preparation by magnetron sputtering, Bi element is volatile, leading to the films which often appear impurity phases. Therefore, Both Bi excessive 5% (B1.05FO) and 8% (B1.08FO) BFO film in Si substrate were prepared by magnetron sputtering. X-Ray Diffraction (XRD) results showed that the BFO thin films fabricated in the Si substrate are perovskite structure, that the B1.08FO film appeared less impurity phases than B1.05FO film, and that stress due to substrate lattice mismatch caused the shift of XRD patterns. In Raman study, it was concluded that both B1.08FO film and B1.05FO film appeared ten Raman peaks in the range from 50cm-1 to 800cm-1, and that B1.08FO Raman peaks intensity was stronger in 137.1cm-1.168.5cm-1 and 215.3cm-1. Spectroscopic ellipsometry test showed that the refractive index and the extinction coefficient of B1.05FO film were 2.25 and 0.07 respectively in 600 nm with 2.67eV of energy gap; the refractive index and the extinction coefficient of B1.08FO film were 2.14 and 0.05 in 600 nm respectively with 2.71eV of energy gap. Atomic Force Microscope (AFM) was used to characterize the film surface morphology, finding that the B1.08FO film prepared in Si substrate was denser while grain size and surface roughness were smaller.


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