Micromachining of ultrananocrystalline diamond

Ultrananocrystalline diamond (UNCD) with grain sizes in the range of 2 - 5 nm is produced using a microwave plasma chemical vapor deposition process with argon-rich C60 or CH4 plasmas. This material has excellent mechanical properties: high hardness and Young modulus, and an extremely low friction coefficient (approximately 0.01). It is resistant to chemical attack, and is potentially biocompatible. These properties make UNCD a very good candidate for a diamond-based microelectromechanical systems (MEMS) technology. We report on the micromachinability of this material by selective seeding, selective growth and reactive ion etching, in conjunction with SiO2 sacrificial layers for fabricating 3-D structures with freestanding or movable parts. These micromachining techniques are used to develop a totally UNCD-made turbine as a demonstration for UNCD-based MEMS.

[1]  Derrick C. Mancini,et al.  Fabrication of MEMS components based on ultrananocrystalline diamond thin films and characterization of mechanical properties. , 2000 .

[2]  D. Wolf,et al.  Role of bonding and coordination in the atomic structure and energy of diamond and silicon grain boundaries , 1998 .

[3]  Derrick C. Mancini,et al.  Ultrananocrystalline diamond thin films for MEMS and moving mechanical assembly devices , 2001 .

[4]  Andrei Vescan,et al.  Electrical characterisation of diamond resistors etched by RIE , 1996 .

[5]  D. Tallant,et al.  Thick stress-free amorphous-tetrahedral carbon films with hardness near that of diamond , 1997 .

[6]  Dieter M. Gruen,et al.  Fullerenes as precursors for diamond film growth without hydrogen or oxygen additions , 1994 .

[7]  D. M. Gruen,et al.  Tem Study of Diamond Films Grown from Fullerene Precursors , 1995 .

[8]  E. Kohn,et al.  Bias-enhanced nucleation of diamond on silicon dioxide , 1997 .

[9]  Egbert Oesterschulze,et al.  Fabrication of integrated diamond cantilevers with tips for SPM applications , 1997 .

[10]  Rajeshuni Ramesham,et al.  Fabrication of diamond microstructures for microelectromechanical systems (MEMS) by a surface micromachining process , 1999 .

[11]  Dieter M. Gruen,et al.  Buckyball microwave plasmas: Fragmentation and diamond‐film growth , 1994 .

[12]  David A. Horner,et al.  Theoretical Studies of Growth of Diamond (110) from Dicarbon , 1996 .

[13]  JOSEPH A. NUTH,et al.  Small-particle physics and interstellar diamonds , 1987, Nature.

[14]  Dieter M. Gruen,et al.  Carbon dimer, C2, as a growth species for diamond films from methane/hydrogen/argon microwave plasmas , 1995 .

[15]  Dieter M. Gruen,et al.  Tem characterization of nanodiamond thin films , 1998 .