| Ultrananocrystalline diamond (UNCD) films offer a number of valuable properties like high Young's modulus, chemical inertness, and low coefficient of friction. These properties combined with small crystal size and film smoothness result in UNCD being very promising for many applications such as surface acoustic wave (SAW) devices, coatings for AFM tips, and films for Micro-Electro-Mechanical System (MEMS) devices.;The process to grow a variety of thin, thick, or conductive UNCD films using a Microwave Plasma Assisted Chemical Vapor Deposition (MPACVD) System are investigated. UNCD films are deposited over a wide pressure range (60--180 Torr) and temperature range (400--800°C). UNCD films were grown on Si (100), p-type boron doped, substrates with thicknesses ranging from 58 nm to greater than 70 mum. The highest growth rate of 1.12 mum/h was achieved at 180 Torr, with gas mixtures of HZ2Ar:CH4 = 4:100:2 sccm and 3 kW microwave power. Film surface roughness, as low as 10 nm, was obtained as measured by AFM Microscope. The conductivity of UNCD diamond films varied with nitrogen flow rate. At 20 sccm flow rate of nitrogen in the gas mixture, the conductivity of UNCD films was found to be 10.3 (O.cm)-1 . |
