Polycrystalline Silicon Carbide Micro- And Nanoelectromechanical Systems

Case Western Reserve University, Cleveland OH

Investigators

Abstract

The goal of this proposal is to advance the state-of-the-art in silicon carbide (SiC) microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS). The primary focus is on polycrystalline SiC (poly-SiC) and surface micromachining as a parallel to polysilicon surface micromachining. Accordingly, the proposed research will fabricate and evaluate the performance of a range of surface micromachined devices that together enable a systematic understanding of the relationships between material properties and device performance for poly-SiC. While the MEMS-scale devices will be fabricated and characterized in our laboratories, the NEMS-scale devices (e.g., resonating nano-beams) will be fabricated and characterized in collaboration with Prof. Michael Roukes of Caltech, whose contribution to this research project will be supported by funding from complementary projects. The central objectives supporting the goal of this proposal are: (1) a low pressure chemical vapor deposition (LPCVD) technology for poly-SiC with deposition temperatures around 600C; (ii) a controlled in-situ doping capability for poly-SiC; (iii) a clear understanding of the poly-SiC material properties and their relation to deposition conditions; and (iv) insight into device performance as related to material properties. The 600C deposition temperature range is significant (from a thermal budget and process compatibility point of view) since polysilicon, the dominant MEMS material, is deposited in this temperature range. This research will build on a unique, large-scale LPCVD furnace recently constructed by our group at CWRU. The furnace is sized for high-volume production of SiC films and thus will provide an enabling platform for the proposed research. Intellectual Merit: SiC is known for its outstanding material properties, which are enabling for applications of MEMS/NEMS in harsh environments (e.g., in presence of high temperatures, corrosive media, erosive conditions, high impact loads) over silicon. Its inherent biocompatibility makes it a leading material for MEMS therapeutic and diagnostic devices. Advancement of poly-SiC MEMS/NEMS state-of-the-art will open new possibilities for advancement and growth of the field. For example, SiC MEMS/NEMS are being pursued for wireless communication and for micro-power generation applications. Broader Impact: The proposed project has impact beyond research, in both education and commercial applications. The knowledge gained will be actively incorporated into our graduate and undergraduate research experiences and educational courses, and disseminated to high school students. The research results will be commercialized through our direct and indirect industrial collaborations. Finally, SiC, being a high performance material, is of interest in many non-MEMS/NEMS applications (e.g., coatings, dielectrics, high power electronics).