Micro-hotplate device

An optical microscope image of the fabricated micro-hotplate device (adapted from Santra et al., 2010a). 

J.S. Suehle, R.E. Cavicchi, M. Gaitan, and S. Semancik. Tin oxide gas sensor fabricated using CMOS micro-hotplates and in-situ processing , IEEE Electron Device Letters 14 (1993), 118-120. 

It then addresses the micro-hotplates concept that has led to the development of different types of micromachined gas sensor devices. The different reahzations of micromachined semiconductor gas sensors are presented thin- and thick-film metal-oxide, field effect, and those using complementary metal-oxide semiconductors (CMOSs) and silicon-on-insulator (SOI) technologies. Finally, recent developments based on gas sensitive nanostructures, polymers, printing and foil-based technologies are highlighted. 

PET foils were used by McAlpine et al. (2007) as the substrate onto which nanotubes were deposited (see Section 6.7.1). The device showed itself to be suitable for measuring NO at room temperature. ZnO nanowires were grown on Pl-based micro-hotplates by Zappa et al. (2012). Zn was sputtered onto the substrate through a shadow mask and then oxidized for 12 hours... 

Cavicchi, R. E., Snehle, J. S., Kreider, K. Q, Gaitan, M. and Chaparala, P. (1995), Fast temperatnre programmed sensing for micro-hotplate gas sensors , IEEE Electron Device Lett., 16(6), 286-8. 

Freestanding oxidized porous Si micro-hotplates were first applied in sensor devices. Tabata (1986) and Tabata et al. (1987) used a 20 pm-thick porous Si membrane, frilly oxidized at 1,000 °C... 

Bolometer 7 Gas flow sensor 7 Micro-hotplates 6 Molecular dynamics approach 4 Monte Carlo simulation 5 Photonic device 7 Room temperature 2-3 Temperature dependence 2 Thermal conductivity 1, 4 Thermal flow sensor 7 Thermally isolating substrate 5... 

Fig. 5.16 Device structure of the THS on Si substrate (5 mm x 5 mm X 0.35 mm) using micro-hotplates.

Polpmides have excellent thermal stability, solvent resistance, radiation resistance, wear resistance, hydrolytic stability, low dielectric constant, high mechanical properties, good chemical resistance and a low dielectric constant. Due to these superior properties, the application field of polyimide has generally been enlarged from printed circuit boards and electrical insulation layers in microelectronics to functional layers of humidity sensors, shielding layers for sensor surfaces and novel platforms for thermal sensor devices, temperature sensor arrays, micro-hotplates integrated into gas sensors and biosensors. 

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