A vertical MOSFET for charge sensing in the convex corner of Si microchannels

Geunbae Lim, Chin-Sung Park, Hong-Kun Lyu, Dong-Sun Kim, Jang-Kyoo Shin, Pyung Choi, and Minho Lee
Kyungpook National University, KP

Keywords: MOSFET, charge sensing, microchannels, MEMS, thiol DNA

Abstract:
In this paper, we will present a vertical MOSFET formed in the convex corner of silicon microchannels which might be useful for detecting charged biomolecules. The cross type microchannels have four MOSFETs and four pairs of source/drain electrodes at each crossing. The non-planar and non-rectangular vertical MOSFET has a effective channel length of 12μm and a effective channel width of 9μm. Electrical characteristics of the vertical MOSFET were measured at room temperature. The measured I-V characteristics exhibits a typical MOSFET behavior with a threshold voltage of –1.6V. Variation of drain current with time was also measured when the MOSFET was dipped into the thiol DNA solution. The drain current decreased and was saturated after 5 minutes, which we believe might be due to the change of threshold voltage caused by charged biomolecules adsorbed on the Au gate. In summary, a vertical MOSFET formed in the convex corner of silicon microchannels is presented, which might be useful for detecting charged biomolecules in the biochemical solutions.

NSTI Nanotech 2003 Conference Technical Program Abstract