Document Type
Conference Proceeding
Language
eng
Publication Date
3-7-2014
Publisher
Society of Photo-Optical Instrumentation Engineers (SPIE)
Source Publication
Proceedings of SPIE 8973, Micromachining and Microfabrication Process Technology XIX,
Abstract
The ability to design and develop 3D microstructures is important for microelectromechanical systems (MEMS) fabrication. Previous techniques used to create 3D devices included tedious steps in direct writing and aligning patterns onto a substrate followed by multiple photolithography steps using expensive, customized equipment. Additionally, these techniques restricted batch processing and placed limits on achievable shapes. Gray-scale lithography enables the fabrication of a variety of shapes using a single photolithography step followed by reactive ion etching (RIE). Micromachining 3D silicon structures for MEMS can be accomplished using gray-scale lithography along with dry anisotropic etching. In this study, we investigated: using MATLAB for mask designs; feasibility of using 1 μm Heidelberg mask maker to direct write patterns onto photoresist; using RIE processing to etch patterns into a silicon substrate; and the ability to tailor etch selectivity for precise fabrication. To determine etch rates and to obtain desired etch selectivity, parameters such as gas mixture, gas flow, and electrode power were studied. This process successfully demonstrates the ability to use gray-scale lithography and RIE for use in the study of micro-contacts. These results were used to produce a known engineered non-planer surface for testing micro-contacts. Surface structures are between 5 μm and 20 μm wide with varying depths and slopes based on mask design and etch rate selectivity. The engineered surfaces will provide more insight into contact geometries and failure modes of fixed-fixed micro-contacts.
Recommended Citation
Stilson, Christopher; Pal, Rajan; and Coutu, Ronald A. Jr., "Fabrication of 3D surface structures using grayscale lithography" (2014). Electrical and Computer Engineering Faculty Research and Publications. 392.
https://epublications.marquette.edu/electric_fac/392
Comments
Published version. Published as a part of Proceedings of SPIE 8973, Micromachining and Microfabrication Process Technology XIX, (7 March 2014): 89730E. DOI. © (2014) Society of Photo-Optical Instrumentation Engineers (SPIE). Used with permission.
Ronald A. Coutu was affiliated with the Air Force Institute of Technology at the time of publication.