title: Piezoelectric actuated micro-resonators based on the growth of diamond on aluminum nitride thin films.
abstract: Unimorph heterostructures based on piezoelectric aluminum nitride (AlN) and diamond thin films are highly desirable for applications in micro- and nanoelectromechanical systems. In this paper, we present a new approach to combine thin conductive boron-doped as well as insulating nanocrystalline diamond (NCD) with sputtered AlN films without the need for any buffer layers between AlN and NCD or polishing steps. The zeta potentials of differently treated nanodiamond (ND) particles in aqueous colloids are adjusted to the zeta potential of AlN in water. Thereby, the nucleation density for the initial growth of diamond on AlN can be varied from very low (10(8) cm(-2)), in the case of hydrogen-treated ND seeding particles, to very high values of 10(11) cm(-2) for oxidized ND particles. Our approach yielding high nucleation densities allows the growth of very thin NCD films on AlN with thicknesses as low as 40 nm for applications such as microelectromechanical beam resonators. Fabricated piezo-actuated micro-resonators exhibit enhanced mechanical properties due to the incorporation of boron-doped NCD films. Highly boron-doped NCD thin films which replace the metal top electrode offer Young's moduli of more than 1000 GPa.
authors.affiliation: Fraunhofer Institute for Applied Solid State Physics, Tullastrasse 72, D-79108 Freiburg, Germany. jan.jakob.hees@iaf.fraunhofer.de
authors.forename: J
authors.initials: J
authors.lastname: Hees
authors.forename: N
authors.initials: N
authors.lastname: Heidrich
authors.forename: W
authors.initials: W
authors.lastname: Pletschen
authors.forename: R E
authors.initials: RE
authors.lastname: Sah
authors.forename: M
authors.initials: M
authors.lastname: Wolfer
authors.forename: O A
authors.initials: OA
authors.lastname: Williams
authors.forename: V
authors.initials: V
authors.lastname: Lebedev
authors.forename: C E
authors.initials: CE
authors.lastname: Nebel
authors.forename: O
authors.initials: O
authors.lastname: Ambacher
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D019245:Compressive Strength; D003217:Conductometry / Q000295:instrumentation*; D003460:Crystallization / Q000379:methods; D018130:Diamond / Q000737:chemistry*; D055119:Elastic Modulus; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D008904:Miniaturization; D010316:Particle Size; D013718:Tensile Strength
chemical_list: D017607:Aluminum Compounds; D008567:Membranes, Artificial; D018130:Diamond; C052045:aluminum nitride