AVS 62nd International Symposium & Exhibition
    MEMS and NEMS Wednesday Sessions
       Session MN+AM-WeA

Paper MN+AM-WeA9
Ni-induced Graphitization for Enhanced Long-term Stability of Ohmic Contact to Polycrystalline 3C-SiC

Wednesday, October 21, 2015, 5:00 pm, Room 211A

Session: Emerging Materials & Fabrication Technologies toward Scalable & Additive Nanomanufacturing II
Presenter: Roya Maboudian, University of California at Berkeley
Authors: S. Chen, University of California at Berkeley
L.E. Luna, University of California at Berkeley
Z. You, Tsinghua University
C. Carraro, University of California at Berkeley
R. Maboudian, University of California at Berkeley
Correspondent: Click to Email

Micro- and nano-electromechanical systems (M/NEMS) technology enables a diverse range of physical and chemical sensing under conditions close to ambient. However, there is a growing interest in sensors that can operate under harsh environments, including high temperature, high pressure, extreme radiation and corrosive. Sensing within these environments necessitates a robust semiconductor platform, different from those employed in traditional Si-based M/NEMS. A robust material, such as silicon carbide (SiC) provides compelling advantages not achievable with Si-based devices. SiC is a wide bandgap semiconductor with excellent mechanical, chemical and electrical stability, and thus is well suited for designing devices capable of operation in many harsh environments. Yet, harsh-environment stable metallization remains one of the key challenges with SiC technology. Here, we present a novel metallization scheme, utilizing solid-state graphitization of SiC, to improve the long-term reliability of Pt/Ti contacts to polycrystalline n-type SiC at high temperature. The metallization scheme includes an alumina protection layer and exhibits low stable contact resistivity even after long-term (500 hr) testing in air at 450 ºc. This study provides a feasible fabrication method and discusses the role of induced graphitic layer on contact stability.