FINITE ELEMENT ANALYSIS OF FABRICATION RELATED THERMAL EFFECTS IN CAPACITIVE MICROMACHINED ULTRASONIC TRANSDUCERS

2006-01-01
Kupnik, Mario
Ergun, Arif S.
Yaralioglu, Goksen G.
Bayram, Barış
Oralkan, Oemer
Wong, Serena H.
Lin, Dersong
Khuri-Yakub, Butrus T.
The accurate prediction of the static operation point of capacitive micromachined ultrasonic transducer (CMUT) membranes is essential for dynamic performance modeling, device design, and device fabrication. We evaluate whether fabrication-related stress effects in CMUT cells cause significant deviations observed between membrane deflection measurements and calculations. Our finite element analysis (FEA) considers the thermal structural interaction associated with the temperature stress history during device fabrication. Specific boundary conditions enable thermal expansion in all directions. Compared to conventional FEAs with one static solution step, we use seven static solution steps using the element birth and death feature of ANSYS to assemble the CMUT cell layer by layer at the appropriate deposition temperatures. We use measured static deflection profiles of metallized and non-metallized membranes with different diameters and thicknesses to extract all unknown parameters for the model. This approach improves the prediction of membrane deflections significantly, and it explains why present models often overestimate the collapse voltage

Suggestions

Finite element simulation of quench hardening
Gür, Cemil Hakan (1996-07-01)
In this study, an efficient finite element model for predicting the temperature field, volume fraction of phases and the evolution of internal stresses up to the residual stress states during quenching of axisymmetrical steel components is developed and implemented. The temperature distribution is determined by considering heat losses to the quenching medium as well as latent heat due to phase transformations. Phase transformations are modelled by discretizing the cooling cuves in a succession of isothermal...
Design and characterization of a buckling-resistant perforated MEMS membrane under residual stress
Bozyigit, Mustafa Anil; Sahin, Asaf Behzat; Bayram, Barış (2020-05-01)
Micro Electro Mechanical Systems (MEMS) membranes are utilized as both transmitter and receiver in acoustic and ultrasound applications. Their operating frequency ranges are determined by their resonance frequencies. Thus, the resonance frequency estimation is one of the most critical parts of the membrane design. In this study, two perforated circular MEMS membranes are designed, microfabricated and characterized to get proper operation under residual stress since this stress might cause buckling of the me...
Residual stress and Young's modulus measurement of capacitive micromachined ultrasonic transducer membranes
Yaralioglu, GG; Ergun, AS; Bayram, Barış; Marentis, T; Khuri-Yakub, BT (2001-01-01)
Membranes supported by posts are used as vibrating elements of capacitive micromachined ultrasonic transducers (CMUTs). The residual stress built up during the fabrication process determines the transducer properties such as resonance frequency, collapse voltage, and gap distance. Hence, it is important to evaluate and control the stress in thin film CMUT membranes. The residual stress in the membrane causes significant vertical displacements at the center of the membrane. The stress bends the membrane post...
Potential Energy Surfaces for Vibrational Structure Calculations from a Multiresolution Adaptive Density-Guided Approach: Implementation and Test Calculations
Sparta, Manuel; Hoyvik, Ida-Marie; Toffolı, Danıele; Christiansen, Ove (American Chemical Society (ACS), 2009-07-30)
A multiresolution procedure to construct potential energy surfaces (PESs) for use in vibrational structure calculations is developed in the framework of the adaptive density-guided approach. The implementation of the method allows the construction of hybrid PESs with different mode-coupling terms calculated with a variety of combinations of electronic structure methods and basis sets. Furthermore, the procedure allows the construction of hybrid PESs that incorporate a variety of contributions and correction...
FINITE ELEMENT ANALYSIS OF CMUTs: CONVENTIONAL VS. COLLAPSE OPERATION MODES
Yaralioglu, Goksen G.; Bayram, Barış; Khuri-Yakub, Butrus T. (2006-01-01)
Collapse mode has been proposed to improve Capacitive Micromachined Ultrasonic Transducer (CMUT) performance in terms of output pressure and receive sensitivity. The focus of this study is to compare the performance of optimized designs for conventional and collapse mode operations using finite element analysis (FEA). For this purpose, we have developed a 2D finite element model for output pressure calculation of CMUTs using commercially available FEA software (ANSYS 10.0). The model is composed of a membra...
Citation Formats
M. Kupnik et al., “FINITE ELEMENT ANALYSIS OF FABRICATION RELATED THERMAL EFFECTS IN CAPACITIVE MICROMACHINED ULTRASONIC TRANSDUCERS,” 2006, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/52344.