Proceedings of the First European Workshop on Low Temperature Electronics
J. Phys. IV France 04 (1994) C6-25-C6-29
On the determination of the effective channel length of MOSFETSN. Patel1, M. Garcia2, S. Titcomb1 and R. Anderson1
1 Cryoelectronics Laboratory, University of Vermont, Burlington VT 04505, U.S.A.
2 Instituto de Ingenieria, Apartodo 40200, Caracas 1040-A, Venezuela
The conventional method used to determine Δ L, the processing induced channel length shortening in MOSFETs at room temperature gives invalid results at 77 K. This error is found to result from the incorrect assumption that the channel resistance is a linear function of effective channel length for the values of gate overdrive normally used for the extraction of Δ L. By restricting gate voltages to the range where this assumption is shown experimentally to be valid, values of Δ L extracted at 77 K are smaller than those extracted at room temperature. This attributed to the reduced source-channel and drain-channel depletion region widths at 77 K at and above threshold.
© EDP Sciences 1994