Unified simulation of Schottky and Ohmic contacts

The Schottky contact is an important consideration in the development of semiconductor devices. This paper shows that a practical Schottky contact model is available for a unified device simulation of Schottky and ohmic contacts. The present model includes the thermionic emission at the metal/semiconductor interface and the spatially distributed tunneling calculated at each grid of semiconductor around the interface. Simulation results of rectifying characteristics of Schottky barrier diodes (SBD's) and contact resistances under high impurity concentration conditions are reasonable, compared with measurements. As examples of application to actual devices, the influence of the contact resistance on salicided MOSFET's with source/drain extension and the immunity of Schottky barrier tunnel transistors (SBTT's) from the short-channel effect (SCE) are demonstrated.