Residual Stress Measurement on Hetero-Epitaxial 3C-SiC Films

2009 ◽  
Vol 615-617 ◽  
pp. 629-632
Author(s):  
Ruggero Anzalone ◽  
Christopher Locke ◽  
Andrea Severino ◽  
Davide Rodilosso ◽  
Cristina Tringali ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Measurement ◽  
Bulk Material ◽  
Chemical Vapour ◽  
Silicon Substrates ◽  
New Class ◽  
Carbon Supply ◽  
Silicon Bulk ◽  
Pressure Regime ◽  
Sic Films

The fabrication of SiC MEMS-based sensors requires new processes able to realize microstructures on 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. This approach puts together the standard silicon bulk microfabrication methodologies with the robust mechanical properties of 3C-SiC. Using this approach we were able to fabricate SiC cantilevers for a new class of pressure sensor. In the present research, chemical vapour deposition (CVD) in the low pressure regime of 3C–SiC on silicon substrates was carried out using silane (SiH4), propane (C3 H8) and hydrogen (H2) as the silicon supply, carbon supply and gas carrier, respectively. The resulting bow in the MEMS structures was evaluated optically and the residual stress in the films calculated using the modified stoney equation and determined to be approximately 300 MPa.

Residual Stress Measurement and Simulation of 3C-SiC Single and Poly Crystal Cantilevers

2010 ◽  
Vol 645-648 ◽  
pp. 865-868 ◽  
Author(s):  
Ruggero Anzalone ◽  
Massimo Camarda ◽  
Daniel Alquier ◽  
M. Italia ◽  
Andrea Severino ◽  
...  
Keyword(s):  
Experimental Data ◽  
Theoretical Study ◽  
Stress Measurement ◽  
Bulk Material ◽  
Raman Shift ◽  
Silicon Substrates ◽  
Free Standing ◽  
Element Analysis ◽  
Micro Fabrication ◽  
Sic Films

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.

3C-SiC Hetero-Epitaxial Films for Sensors Fabrication

2008 ◽  
Vol 54 ◽  
pp. 411-415 ◽  
Author(s):  
Ruggero Anzalone ◽  
Andrea Severino ◽  
Christopher Locke ◽  
Davide Rodilosso ◽  
Cristina Tringali ◽  
...  
Keyword(s):  
Bulk Material ◽  
Epitaxial Films ◽  
Sem Analysis ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
New Class ◽  
Silicon Bulk ◽  
Polar Figure ◽  
Hostile Environments ◽  
Sic Film

Silicon Carbide (SiC) is a very promising material for the fabrication of a new category of sensors and devices, to be used in very hostile environments (high temperature, corrosive ambient, presence of radiation, etc.). The fabrication of SiC MEMS-based sensors requires new processes able to realize microstructures on bulk material or on the SiC surface. The hetero-epitaxial growth of 3CSiC on silicon substrates allows one to overcome the traditional limitations of SiC microfabrication. This approach puts together the standard silicon bulk microfabrication methodologies with the robust mechanical properties of 3C-SiC. Using this approach we were able to fabricate SiC cantilevers for a new class of pressure sensor. The geometries studied were selected in order to study the internal residual stress of the SiC film. X-Ray Diffraction polar figure and Bragg- Brentano scan analysis were used to check to crystal structure and the orientations of the film. SEM analysis was performed to analyze the morphology of the released MEMS structures.

Silicon carbide emitter diodes by LPCVD (low-pressure chemical vapour deposition) using di-tert-butylsilane

1992 ◽  
Vol 70 (10-11) ◽  
pp. 946-948
Author(s):  
S. B. Hewitt ◽  
S.-P. Tay ◽  
N. G. Tarr ◽  
A. R. Boothroyd
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Low Pressure ◽  
Silicon Substrates ◽  
Phosphorus Doping ◽  
Forward Current ◽  
Pressure Chemical ◽  
Sic Films

Stoichiometric SiC films formed by low-pressure chemical vapour deposition from a di-tert-butylsilane source with in situ phosphorus doping from tert-butylphosphine were used as emitters in heterojunction diodes fabricated on lightly doped silicon substrates. Diode characteristics are nearly ideal, with forward current dominated by injection-diffusion in the silicon substrate.

scholarly journals Using Welding Simulation and Ultrasonic Method to Evaluate Residual Stress in Stainless Steel Welded Plates

2012 ◽  
Author(s):  
Yashar Javadi ◽  
Mohammadreza Hadizadeh Raeisi ◽  
Hamed Salimi Pirzaman ◽  
Mehdi Ahmadi Najafabadi
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Acoustic Waves ◽  
Stress Measurement ◽  
Bulk Material ◽  
Three Dimensional ◽  
Ultrasonic Waves ◽  
Welding Simulation

When a material is under mechanical load, the stresses change the velocity of acoustic waves because of acoustoelastic effect. This property can be employed for stress measurement in the material itself when the stress concerns the surface of the material, or in the bulk material. This technique involves with critically refracted longitudinal waves that propagate parallel to the surface, i. e. LCR waves. This paper presents a three dimensional thermo-mechanical analysis to evaluate welding residual stresses in plate-plate joint of AISI stainless steel 304L. After finite element simulation, the residual stresses were evaluated by LCR ultrasonic waves. This paper introduces a combination of “Finite Element Welding Simulation” and “Ultrasonic Stress Measurement using the LCR Wave” which is called as “FELcr”. The capabilities of FELCR in residual stress measurement are confirmed here. It has been shown that predicted residual stress from three dimensional FE analyses is in reasonable agreement with measured residual stress from LCR method.

Advanced Stress Analysis by Micro-Structures Realization on High Quality Hetero-Epitaxial 3C-SiC for MEMS Application

2011 ◽  
Vol 679-680 ◽  
pp. 133-136 ◽  
Author(s):  
Ruggero Anzalone ◽  
Massimo Camarda ◽  
Giuseppe D'Arrigo ◽  
Christopher Locke ◽  
Andrea Canino ◽  
...  
Keyword(s):  
Experimental Data ◽  
Residual Stress ◽  
Bulk Material ◽  
Simulated Data ◽  
Silicon Substrates ◽  
Exponential Approximation ◽  
High Quality ◽  
Micro Fabrication ◽  
High Residual Stress ◽  
Micro Structures

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.

Standard Sample Package for Calibration of X-Ray Stress Measurement

2013 ◽  
Vol 768-769 ◽  
pp. 242-245
Author(s):  
Shoichi Yasukawa ◽  
Tatsuki Miyoshi ◽  
Masayuki Yamamoto ◽  
Takashi Yamamoto ◽  
Shinichi Ohya
Keyword(s):  
Residual Stress ◽  
Standard Sample ◽  
Stress Measurement ◽  
Bulk Material ◽  
Measurement Instrument ◽  
Powder Particle Size ◽  
Standard Samples ◽  
Beam Position ◽  
X Ray ◽  
Wide Range

The purpose of our study is to provide standard samples for X-ray stress measurement. Typically zero adjustment is performed by a stress free sample which is a fine powder of pure metal. However, if the sample has stress (not stress-free), the stress value obtained by measurement can contain the errors caused by each stress measurement instrument. To solve this instrumental error, we have created a standard sample package. The sample package includes the following three samples. 1) Fluorescent powder to confirm the beam position and size. 2) Iron powder (particle size 6-8μm) to calibrate the zero-stress. 3) Bulk iron material which has approx. -100(MPa) of residual stress. Each sample has been laid out in a 6mm thick plate, and each sample can be selected by sliding the plate manually. By measuring the bulk material and the powder, correction and calibration of the stress measurement instrument is possible. The manufacturing process employed in this study has confirmed that the iron bulk material does not have residual stress and FWHM changes over time in the past 20 years. Therefore, the standard sample can be used semi permanently by adequate management. Correction of instrument by using this standard sample package increases the reliability of X-ray stress measurement method which will help to employ it in a wide range of practical uses.

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