Microfabrication of vacuum-sealed cavities with nanocrystalline and ultrananocrystalline diamond membranes and their characteristics

Vacuum-sealed cavities featuring diamond membranes are fabricated using plasma-activated direct bonding technology. A chemical mechanical polished (CMP) silicon dioxide interlayer, deposited on diamond with a high temperature oxide (HTO) process at 850 degrees C in a low pressure chemical vapor deposition (LPCVD) furnace, is employed for successful direct bonding and vacuum cavity formation. The circular cavities are defined on the thermally grown oxide of the phosphorus-doped Si wafer (4-in, < 100 >, 1.2 Omega/sq) using reactive ion etching (RIE). The same microfabrication steps are applied for low residual stress (i.e. <50 MPa) nanocrystalline (NCD) and ultrananocrystalline (UNCD) diamonds to determine and compare membrane characteristics. For both diamond types, successful microfabrication of membranes is demonstrated using the optimized process flow. Profilometer measurements of membrane deflection are compared with finite element modeling (FEM), and indicate a Young's modulus of 1000 GPa for NCD and 850 GPa for UNCD. Furthermore, FEM analysis suggests the residual stress of UNCD membrane is approximately 100 MPa tensile, whereas NCD one does not show any significant residual stress (<50 MPa). Our results show that NCD is a more promising choice than UNCD as a membrane material for electromechanical transducers.


Fabrication of SiO2-stacked diamond membranes and their characteristics for microelectromechanical applications
Bayram, Barış (Elsevier BV, 2011-04-01)
Diamond is a promising microelectromechanical systems (MEMS) material due to its high Young's Modulus and very large thermal conductivity. In this work, ultrananocrystalline diamond was stacked between silicon dioxide to form thermally-stable and robust membranes. These SiO2-stacked diamond layers were processed into MEMS-compatible membranes. For comparison, membranes composed of only SiO2 were fabricated as well. The structural characteristics of these membranes are compared and analyzed for membranes of ...
Flexible organic photovoltaics from zinc oxide nanowires grown on transparent and conducting single walled carbon nanotube thin films
Ünalan, Hüsnü Emrah; Kuo, Daniel; Parekh, Bhavin; Amaratunga, Gehan; Chhowalla, Manish (Royal Society of Chemistry (RSC), 2008-01-01)
The fabrication of flexible organic photovoltaics (OPVs) which utilize transparent and conducting single walled carbon nanotube (SWNT) thin films as current collecting electrodes on plastic substrates in zinc oxide nanowire (ZnO NW)/poly(3-hexylthiophene) (P3HT) bulk heterojunction photovoltaic devices is reported. The bulk heterojunctions for exciton dissociation are created by directly growing ZnO nanowires from solution on the SWNT electrodes and spin coating the P3HT polymer. A maximum OPV power convers...
Electrical characterization of vacuum-deposited n-CdS/p-CdTe heterojunction devices
Bayhan, H; Ercelebi, C (IOP Publishing, 1997-05-01)
The effects of post-deposition processes such as CdCl2 dip and/or annealing in air on the material and device properties of vacuum-evaporated Au-CdTe/CdS-TO heterojunction solar cells have been investigated. The CdCl2 dip followed by air annealing at 300 degrees C for 5 min improved the device efficiency significantly, resulting in decreased CdTe resistivity and enhanced grain size. The temperature-dependent current-voltage analysis indicated that above 280 K interface recombination dominates the current tr...
Direct measurement of charge transport through helical poly(ethyl propiolate) nanorods wired into gaps in single walled carbon nanotubes
Wang, Nan; Yano, Koji; Durkan, Colm; Plank, Natalie; Welland, Mark E.; Zhang, Yan; Ünalan, Hüsnü Emrah; Mann, Mark; Amaratunga, G. A. J.; Milne, William I. (IOP Publishing, 2009-03-11)
We report the direct measurement of electrical transport through rod-like polymer molecules, of poly(ethyl propiolate) (PEP), utilizing single walled carbon nanotubes (SWNTs) as electrodes. The electrical properties of the devices were measured (i) before cutting a SWNT, (ii) when a SWNT was cut and (iii) after PEP deposition into the nanoscale gap in a cut SWNT. The gate-dependent electrical properties showed a reduction in current from I-on = 2.4 x 10(-7) A for SWNT devices to I-on = 3.6 x 10(-9) A for PE...
Design of a microbial sensor using conducting polymer of 4-(2,5-di(thiophen-2-yl)-1H-pyrrole-1-l) benzenamine
Tuncagil, Sevinc; ODACI DEMİRKOL, DİLEK; Yidiz, Ersin; TİMUR, SUNA; Toppare, Levent Kamil (Elsevier BV, 2009-03-28)
A microbial biosensor based on Gluconobacter oxydans cells immobilized on the conducting polymer of 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)benzenamine (SNS-NH2) coated onto the Surface of graphite electrode was constructed. The proposed biosensor was characterized using glucose as the Substrate. The linear relation was observed in the range of 0.1-2.5 mM and defined by the equation y = 0.415x + 0.377 (R-2 = 0.986). Analytical characterization, effects of electropolymerization time, pH, cell amount and the ...
Citation Formats
B. Bayram, “Microfabrication of vacuum-sealed cavities with nanocrystalline and ultrananocrystalline diamond membranes and their characteristics,” DIAMOND AND RELATED MATERIALS, pp. 1149–1154, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/39373.