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Title: Novel in situ mechanical testers to enable integrated metal surface micro-machines.

Abstract

The ability to integrate metal and semiconductor micro-systems to perform highly complex functions, such as RF-MEMS, will depend on developing freestanding metal structures that offer improved conductivity, reflectivity, and mechanical properties. Three issues have prevented the proliferation of these systems: (1) warpage of active components due to through-thickness stress gradients, (2) limited component lifetimes due to fatigue, and (3) low yield strength. To address these issues, we focus on developing and implementing techniques to enable the direct study of the stress and microstructural evolution during electrodeposition and mechanical loading. The study of stress during electrodeposition of metal thin films is being accomplished by integrating a multi-beam optical stress sensor into an electrodeposition chamber. By coupling the in-situ stress information with ex-situ microstructural analysis, a scientific understanding of the sources of stress during electrodeposition will be obtained. These results are providing a foundation upon which to develop a stress-gradient-free thin film directly applicable to the production of freestanding metal structures. The issues of fatigue and yield strength are being addressed by developing novel surface micromachined tensile and bend testers, by interferometry, and by TEM analysis. The MEMS tensile tester has a ''Bosch'' etched hole to allow for direct viewing of themore » microstructure in a TEM before, during, and after loading. This approach allows for the quantitative measurements of stress-strain relations while imaging dislocation motion, and determination of fracture nucleation in samples with well-known fatigue/strain histories. This technique facilitates the determination of the limits for classical deformation mechanisms and helps to formulate a new understanding of the mechanical response as the grain sizes are refined to a nanometer scale. Together, these studies will result in a science-based infrastructure to enhance the production of integrated metal--semiconductor systems and will directly impact RF MEMS and LIGA technologies at Sandia.« less

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
876252
Report Number(s):
SAND2005-7067
TRN: US200606%%104
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; DEFORMATION; DISLOCATIONS; ELECTRODEPOSITION; FRACTURES; GRAIN SIZE; INTERFEROMETRY; MECHANICAL PROPERTIES; MICROSTRUCTURE; NUCLEATION; PRODUCTION; PROLIFERATION; REFLECTIVITY; THIN FILMS; YIELD STRENGTH; Tensile properties.; Mechanical wear.; Microelectromechanical systems.

Citation Formats

Follstaedt, David Martin, de Boer, Maarten Pieter, Kotula, Paul Gabriel, Hearne, Sean Joseph, Foiles, Stephen Martin, Buchheit, Thomas Edward, and Dyck, Christopher William. Novel in situ mechanical testers to enable integrated metal surface micro-machines.. United States: N. p., 2005. Web. doi:10.2172/876252.
Follstaedt, David Martin, de Boer, Maarten Pieter, Kotula, Paul Gabriel, Hearne, Sean Joseph, Foiles, Stephen Martin, Buchheit, Thomas Edward, & Dyck, Christopher William. Novel in situ mechanical testers to enable integrated metal surface micro-machines.. United States. https://doi.org/10.2172/876252
Follstaedt, David Martin, de Boer, Maarten Pieter, Kotula, Paul Gabriel, Hearne, Sean Joseph, Foiles, Stephen Martin, Buchheit, Thomas Edward, and Dyck, Christopher William. 2005. "Novel in situ mechanical testers to enable integrated metal surface micro-machines.". United States. https://doi.org/10.2172/876252. https://www.osti.gov/servlets/purl/876252.
@article{osti_876252,
title = {Novel in situ mechanical testers to enable integrated metal surface micro-machines.},
author = {Follstaedt, David Martin and de Boer, Maarten Pieter and Kotula, Paul Gabriel and Hearne, Sean Joseph and Foiles, Stephen Martin and Buchheit, Thomas Edward and Dyck, Christopher William},
abstractNote = {The ability to integrate metal and semiconductor micro-systems to perform highly complex functions, such as RF-MEMS, will depend on developing freestanding metal structures that offer improved conductivity, reflectivity, and mechanical properties. Three issues have prevented the proliferation of these systems: (1) warpage of active components due to through-thickness stress gradients, (2) limited component lifetimes due to fatigue, and (3) low yield strength. To address these issues, we focus on developing and implementing techniques to enable the direct study of the stress and microstructural evolution during electrodeposition and mechanical loading. The study of stress during electrodeposition of metal thin films is being accomplished by integrating a multi-beam optical stress sensor into an electrodeposition chamber. By coupling the in-situ stress information with ex-situ microstructural analysis, a scientific understanding of the sources of stress during electrodeposition will be obtained. These results are providing a foundation upon which to develop a stress-gradient-free thin film directly applicable to the production of freestanding metal structures. The issues of fatigue and yield strength are being addressed by developing novel surface micromachined tensile and bend testers, by interferometry, and by TEM analysis. The MEMS tensile tester has a ''Bosch'' etched hole to allow for direct viewing of the microstructure in a TEM before, during, and after loading. This approach allows for the quantitative measurements of stress-strain relations while imaging dislocation motion, and determination of fracture nucleation in samples with well-known fatigue/strain histories. This technique facilitates the determination of the limits for classical deformation mechanisms and helps to formulate a new understanding of the mechanical response as the grain sizes are refined to a nanometer scale. Together, these studies will result in a science-based infrastructure to enhance the production of integrated metal--semiconductor systems and will directly impact RF MEMS and LIGA technologies at Sandia.},
doi = {10.2172/876252},
url = {https://www.osti.gov/biblio/876252}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Oct 01 00:00:00 EDT 2005},
month = {Sat Oct 01 00:00:00 EDT 2005}
}