The objective of this research is to investigate unconventional cantilever cross sections for applications in high speed Atomic Force Microscopy (AFM). High speed AFM is of interest for quality control in nanomanufacturing. The cantilevers will be made via polymer molding technology, with the plastic converted via heat treating to silicon carbide. Methods for making defect free cantilevers with geometries that are difficult if not impossible using the standard manufacturing methods will be investigated.
The intellectual merit of this project is an increased understanding of application of preceramic polymers for use in making Micro Electro-Mechanical Systems (MEMS). This work will expand the repertoire of cantilever geometries accessible to MEMS researchers. In addition, it will elucidate the role of thermal conversion conditions in controlling the formation of cracks in this class of materials. These results can be applied to any number of applications for preceramic polymers.
The broader impact is to enable the wider use of high speed AFM for quality control in nanomanufacturing as well as allowing detailed imaging of chemical and biological dynamical processes. The combined performance advantages of higher resonant frequency (and thus higher scanning speed) and the ability to make cantilevers using inexpensive molding techniques would be of substantial benefit to the nanomanufacturing, microelectronics, and biomedical industries. The demonstration of a method to easily enable manufacturing of silicon carbide based MEMS would have a significant impact on the competitiveness of the microelectronics industry internationally. Finally, students involved in this project will gain exposure to advanced MEMS fabrication techniques, as well as a unique range of expertise at the intersection of electrical and plastics engineering, physics, chemistry, and materials science. In particular, the development of new perspectives and creative problem solving skills is integral to interdisciplinary research of this nature and will foster student success.
The goal of this project was to investigate the use of polymer molding techniques for making novel structures for use in Micro Electro-Mechanical Systems (MEMS). The anticipated outcome was the demonstration of a technique for making mechanical structures, such as cantilevers for Atomic Force Microscopes (AFM) which would have higher operating frequencies as compared to structures made using conventional MEMS lithography processes. A special type of plastic, known as pre-ceramic polymers, was employed int he study. This polymer can be molded using conventional techniques, enabling the formation of complex structures. However, this polymer, can be transformed via heating to form ultra-hard, high temperature resistant silicon carbide (SiC). Thus the project end result is to form highly durable MEMS with structures that would be difficult to form via the typical process. This could have a beneficial impact on the MEMS market - currently valued at $10B - by enabling further innovation in MEMS design. The project was successful in overcoming the fabrication challenges associated with employing polymer micromolding. SiC based cantilevers for MEMS were fabricated in a manner that is compatible with silicon microfabrication processes, thus enabling it to be integrated into current MEMS/microelectronics fabrication lines without a need for new facilities. This project also resulted in a new line of industry supported research, when it was discovered during the course of working on this project that the SiC produced is pure enough to be considered semiconductor grade. This discovery has led to an active project with a leading semiconductor equipment manufacturer that is investigating the use of SiC in improving the efficiency of silicon solar cells.
