Localized heating on silicon field effect transistors: Device fabrication and temperature measurements in fluid

• Published in: Lab on a chip Vol. 9; no. 19; pp. 2789 - 2795
• Main Authors: Elibol, Oguz H., Reddy Jr, Bobby, Nair, Pradeep R., Dorvel, Brian, Butler, Felice, Ahsan, Zahab S., Bergstrom, Donald E., Alam, Muhammad A., Bashir, Rashid
• Format: Journal Article
• Language: English
• Published: England 01.01.2009
• Subjects: Fluorescent Dyes - chemistry; Hot Temperature; Lab-On-A-Chip Devices; Microwaves; Silicon - chemistry; Surface Properties; Transistors, Electronic
• ISSN: 1473-0197; 1473-0189
• DOI: 10.1039/b906048k

We demonstrate electrically addressable localized heating in fluid at the dielectric surface of silicon-on-insulator field-effect transistors via radio-frequency Joule heating of mobile ions in the Debye layer. Measurement of fluid temperatures in close vicinity to surfaces poses a challenge due to the localized nature of the temperature profile. To address this, we developed a localized thermometry technique based on the fluorescence decay rate of covalently attached fluorophores to extract the temperature within 2 nm of any oxide surface. We demonstrate precise spatial control of voltage dependent temperature profiles on the transistor surfaces. Our results introduce a new dimension to present sensing systems by enabling dual purpose silicon transistor-heaters that serve both as field effect sensors as well as temperature controllers that could perform localized bio-chemical reactions in Lab on Chip applications.