Fundamentals and application of materials integration for low- power piezoelectrically actuated ultra-nanocrystalline diamond MEMS/NEMS O. Auciello, 1,2 S. Srinivasan, 1* J. Hiller, 3 A.V. Sumant, 2 and B. Kabius 3 1 Materials Science Division, 2 Center for Nanoscale Materials, 3 Center for Electron Microscopy, Argonne, IL 60439 ABSTRACT Most current micro/nanoelectromechanical systems (MEMS/NEMS) are based on silicon. However, silicon exhibits relatively poor mechanical/tribological properties, compromising applications to several projected MEMS/NEMS devices, particularly those that require materials with high Young’s modulus for MEMS resonators or low surface adhesion forces for MEMS/NEMS working in conditions with extensive surface contact. Diamond films with superior mechanical/tribological properties provide an excellent alternative platform material. Ultrananocrystalline diamond (UNCD ® ) in film form with 2-5 nm grains exhibits excellent properties for high-performance MEMS/NEMS devices. Concurrently, piezoelectric Pb(Zr x Ti 1-x )O 3 (PZT) films provide high sensitivity/low electrical noise for sensing/high-force actuation at relatively low voltages. Therefore, integration of PZT and UNCD films provides a high-performance platform for advanced MEMS/NEMS devices. This paper describes the bases of such integration and demonstration of low voltage piezoactuated hybrid PZT/UNCD cantilevers. Keyword list lead zirconate titanate; Pb(Zr,Ti)O 3 ; thin films; diamond; piezoelectric; ferroelectric; MEMS; resonators. 1. INTRODUCTION: Most micro/nanoelectromechanical systems (MEMS/NEMS) devices currently under research and/or development are based on silicon, mainly because the MEMS/NEMS industry is leveraging the microfabrication processes developed for the microelectronics devices. However, the relatively poor mechanical/tribological properties of Si compromise applications to some devices, particularly those that require high Young’s modulus, such as resonators, and low or no stiction, such as switches or other MEMS/NSM devices involving extensive surface-to-surface contact of components. Alternatively, diamond, with very high Young’s modulus and negligible surface adhesion, on contact, can yield high-performance MEMS/NEMS devices, such as resonators, switches, and other MEMS/NEMS devices involving extensive surface-to-surface contact components. Fabrication of diamond- based devices requires growth of diamond films on appropriate substrates followed by photolithography and etching to release moving structures (e.g., cantilevers, beams). Ultrananocrystalline diamond (UNCD ® ) developed at patented at Argonne National Laboratory (ANL), exhibits superior mechanical / tribological properties combined with smoother surface morphology (~ 3-5 nm rms roughness) and the lowest diamond deposition temperature demonstrated today (~ 400 ˚C), compared with single crystal diamond, microcrystalline diamond (MCD), nanocrystalline diamond (NCD), diamond-like (DLC), and SiC films, which are also being investigated for development of non-Si based MEMS/NEMS devices. [1] UNCD films are grown on substrates exposed to Ar-rich CH 4 microwave plasmas, [1,2], which yield 3-5 nm diamond grains and 0.4 nm wide grain boundaries with sp 3 and sp 2 bonding, and about 10 nm grains and 1-2 nm wide grain boundaries when growing UNCD films with N 2 addition to the A/CH 4 chemistry, to produce nitrogen-doped UNCD films with relatively high electrical conductivity [up to ~ 260 (W cm) -1 ].[3] This nanostructure is named UNCD in order to distinguish this material from NCD films grown with H-rich/CH 4 plasmas that yield films with 30-100 nm grain sizes. UNCD exhibits a unique combination Invited Paper Micro- and Nanotechnology Sensors, Systems, and Applications, edited by Thomas George, M. Saif Islam, Achyut K. Dutta, Proc. of SPIE Vol. 7318, 73181B · © 2009 SPIE · CCC code: 0277-786X/09/$18 · doi: 10.1117/12.822798 Proc. of SPIE Vol. 7318 73181B-1