Future Trends in Microelectronics: Up the Nano Creek

Will the Insulated Gate Transistor Concept Survive Next Decade?

O. Engström

Dept. of Microtechnology and NanoscienceChalmers University of Technology, SE-412 96 Göteborg, Sweden

1. Introduction

The increasing influence of electronics on human life in the past couple of decades has promoted the MOS transistor to a device of similar significance for cultural change as, for example, the rotating electric motor and the combustion engine. A key property of the MOSFET, which has made this ranking possible, is its potential for fast and steady improvement. In the early 1970’s, when the current-voltage characteristics of the device reasonably well could be described by the one-dimensional Ihantola-Moll model,¹ the gate channel was long enough that the electrostatic influence from source and drain contacts could be neglected or considered as a slight perturbation at higher drain voltages. The downscaling process, which has been going on since then, is presently at a stage where the electric field distribution between source and drain has become too complicated for simple analytical expressions in characterizing the device. Bulk CMOS technology has reached a point where further development includes a considerable “squeezing” of parameter values by small geometrical changes and by the introduction of novel materials, combined with the acceptance of numerous tradeoffs in the design process.

Many of these problems in the scaling of bulk MOSFETs have a straight-forward solution in silicon-on-insulator ...