Ballistic and overshoot electron transport in bulk semiconductors and in submicronic devices

Abstract

The possibility of ballistic and overshoot transport in bulk semiconductor and submicronic devices are discussed using both simple analytical calculation and more exact Monte Carlo simulation. Assuming a homogeneous semiconductor, it appears possible, using a really ballistic motion of electrons to achieve over very short distances (a few tenths of a micron) higher velocities than in the overshoot motion. The influence of the doping concentration and of the operating temperature, as well as the improvement which could be achieved by using other materials, is also discussed. The potential of such ballistic motion and velocity overshoot in a real submicronic device is then assessed; it is shown that, due to spatial nonuniformities, additional phenomena occur which might considerably change, and often reduce, the velocity of the carriers.