Mechanical Proprieties and Residual Stress Evaluation on Heteroepitaxial 3C-SiC/Si for MEMS Application

2012 ◽  
Vol 711 ◽  
pp. 51-54 ◽  
Author(s):  
Ruggero Anzalone ◽  
Giuseppe D'Arrigo ◽  
Massimo Camarda ◽  
Nicolò Piluso ◽  
Andrea Severino ◽  
...  

SiC is a candidate material for micro- and nano-electromechanical systems (MEMS and NEMS). The hetero-epitaxial growth of 3C-SiC on silicon substrates allows one to overcome the traditional limitations of SiC micro-fabrication, but the high residual stress created during the film grow limits the development of the material for these applications. In this work, in order to evaluate the amount of residual stress released from the epi-film, different micro-machined structures were developed. Through the measurement of natural resonant frequencies and Raman shift analysis, a strong relationship between the mechanical proprieties of the material (Young’s modulus) and the film crystal quality (defect density) was observed.

2011 ◽  
Vol 679-680 ◽  
pp. 133-136 ◽  
Author(s):  
Ruggero Anzalone ◽  
Massimo Camarda ◽  
Giuseppe D'Arrigo ◽  
Christopher Locke ◽  
Andrea Canino ◽  
...  

SiC is a candidate material for micro- and nano-electromechanical systems (MEMS and NEMS). The fabrication of SiC MEMS-based sensors requires new processes able to realize microstructures on either bulk material or on the SiC surface. The hetero-epitaxial growth of 3C-SiC on silicon substrates allows one to overcome the traditional limitations of SiC micro-fabrication, but the high residual stress created during the film grow limits the development of the material for these applications. In order to evaluate the amount of residual stress released from the epi-film, different micro-machined structures were developed. Finite elements simulations of the micro-machined structures have also been carried out in order to evaluate, in detail, the stress field inside the structures and to test the analytical model used. With finite element modeling a exponential approximation of the stress relationship was studied, yielding a better fit with the experimental data. This study shows that this new approximation of the total residual stress function reduces the disagreement between experimental and simulated data.


2010 ◽  
Vol 645-648 ◽  
pp. 865-868 ◽  
Author(s):  
Ruggero Anzalone ◽  
Massimo Camarda ◽  
Daniel Alquier ◽  
M. Italia ◽  
Andrea Severino ◽  
...  

The fabrication of SiC MEMS-based sensors requires new processes able to realize microstructures on either bulk material or on the SiC surface. The hetero-epitaxial growth of 3C-SiC on silicon substrates allows one to overcome the traditional limitations of SiC micro-fabrication. In this work a comparison between single crystal and poly crystal 3C-SiC micro-machined structures will be presented. The free-standing structures realized (cantilevers and membrane) are also a suitable method for residual field stress investigation in 3C-SiC films. Measurement of the Raman shift indicates that the mono and poly-crystal 3C-SiC structures release the stress in different ways. Finite element analysis was performed to determine the stress field inside the films and provided a good fit to the experimental data. A comprehensive experimental and theoretical study of 3C-SiC MEMS structures has been performed and is presented.


Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1072
Author(s):  
Sergio Sapienza ◽  
Matteo Ferri ◽  
Luca Belsito ◽  
Diego Marini ◽  
Marcin Zielinski ◽  
...  

3C-SiC is an emerging material for MEMS systems thanks to its outstanding mechanical properties (high Young’s modulus and low density) that allow the device to be operated for a given geometry at higher frequency. The mechanical properties of this material depend strongly on the material quality, the defect density, and the stress. For this reason, the use of SiC in Si-based microelectromechanical system (MEMS) fabrication techniques has been very limited. In this work, the complete characterization of Young’s modulus and residual stress of monocrystalline 3C-SiC layers with different doping types grown on <100> and <111> oriented silicon substrates is reported, using a combination of resonance frequency of double clamped beams and strain gauge. In this way, both the residual stress and the residual strain can be measured independently, and Young’s modulus can be obtained by Hooke’s law. From these measurements, it has been observed that Young’s modulus depends on the thickness of the layer, the orientation, the doping, and the stress. Very good values of Young’s modulus were obtained in this work, even for very thin layers (thinner than 1 mm), and this can give the opportunity to realize very sensitive strain sensors.


1992 ◽  
Vol 25 (3) ◽  
pp. 130 ◽  
Author(s):  
P. Palanichamy ◽  
A. Joseph ◽  
K. V. Kasiviswanathan ◽  
D. K. Bhattacharya ◽  
Baldev Raj

2006 ◽  
Vol 524-525 ◽  
pp. 697-702 ◽  
Author(s):  
Shinobu Okido ◽  
Hiroshi Suzuki ◽  
K. Saito

Residual stress generated in Type-316 austenitic stainless steel butt-weld jointed by Inconel-182 was measured using a neutron diffraction method and compared with values calculated using FEM analysis. The measured values of Type-316 austenitic stainless steel as base material agreed well with the calculated ones. The diffraction had high intensity and a sharp profile in the base metal. However, it was difficult to measure the residual stress at the weld metal due to very weak diffraction intensities. This phenomenon was caused by the texture in the weld material generated during the weld procedure. As a result, this texture induced an inaccurate evaluation of the residual stress. Procedures for residual stress evaluation to solve this textured material problem are discussed in this paper. As a method for stress evaluation, the measured strains obtained from a different diffraction plane with strong intensity were modified with the ratio of the individual elastic constant. The values of residual stress obtained using this method were almost the same as those of the standard method using Hooke’s law. Also, these residual stress values agreed roughly with those from the FEM analysis. This evaluation method is effective for measured samples with a strong texture like Ni-based weld metal.


1998 ◽  
Vol 22 (3) ◽  
pp. 22-25 ◽  
Author(s):  
L. Berka ◽  
M. Sova ◽  
G. Fischer

Author(s):  
Itaru Muroya ◽  
Youichi Iwamoto ◽  
Naoki Ogawa ◽  
Kiminobu Hojo ◽  
Kazuo Ogawa

In recent years, the occurrence of primary water stress corrosion cracking (PWSCC) in Alloy 600 weld regions of PWR plants has increased. In order to evaluate the crack propagation of PWSCC, it is required to estimate stress distribution including residual stress and operational stress through the wall thickness of the Alloy 600 weld region. In a national project in Japan for the purpose of establishing residual stress evaluation method, two test models were produced based on a reactor vessel outlet nozzle of Japanese PWR plants. One (Test model A) was produced using the same welding process applied in Japanese PWR plants in order to measure residual stress distribution of the Alloy 132 weld region. The other (Test model B) was produced using the same fabrication process in Japanese PWR plants in order to measure stress distribution change of the Alloy 132 weld region during fabrication process such as a hydrostatic test, welding a main coolant pipe to the stainless steel safe end. For Test model A, residual stress distribution was obtained using FE analysis, and was compared with the measured stress distribution. By comparing results, it was confirmed that the FE analysis result was in good agreement with the measurement result. For mock up test model B, the stress distribution of selected fabrication processes were measured using the Deep Hole Drilling (DHD) method. From these measurement results, it was found that the stress distribution in thickness direction at the center of the Alloy 132 weld line was changed largely during welding process of the safe end to the main coolant pipe.


2014 ◽  
Vol 496-500 ◽  
pp. 2444-2451
Author(s):  
Qiang Zeng ◽  
Dai Qin Tao ◽  
Zheng Zhou ◽  
Xiao Qian Li

Basing on a giant truss, this passage did a macro assessment of welding resjdual stress by the changes of material hardness which was measured by brinell hardness method after welding. This experiment measured about 1728 measurement points on 72 nodes. Statistical analysis of the hardness data shows that hardness of base metal decreases in the area of HAZ ,and plastic of welded joints increases.


2010 ◽  
Vol 645-648 ◽  
pp. 255-258 ◽  
Author(s):  
Nicolò Piluso ◽  
Andrea Severino ◽  
Massimo Camarda ◽  
Ruggero Anzalone ◽  
Andrea Canino ◽  
...  

Raman microscopy has been used to study transport properties in hetero-epitaxial 3C-SiC/Si thin films. By an accurate analysis of the Longitudinal Optic phonon-plasmon coupled (LOPC) modes in n-type doped 3C-SiC films, free carrier density and mobility has been determined. A study of doped 3C-SiC reveals a strong relationship between the calculated free carrier density and both the C/Si ratio used during the epitaxial process and Silicon substrates orientation on which 3C-SiC thin films were grown (maintaining the N2 gas flow rate). The free carrier density obtained is in the range between 5x1016 cm-3 and 4x1018 cm-3. Epitaxial films grown on (111) Si substrates show a higher free carrier density and a lower dependence on C/Si ratios as compared to films grown on (100) Si substrates.


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