Reducing the Resistance of Ohmic Contacts Using Resonant Tunneling
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01
The resistance of ohmic contacts on semiconductors is attributed to the tunneling resistance of a depleted Schottky layer at the metal-semiconductor interface. Conduction takes place through tunneling across the Schottky depletion layer. The contact resistance is made small by using a highly-doped semiconductor permitting a very thin Schottky layer ls . A typical conduction-band diagram of a metal-semiconductor ohmic contact is shown in Fig. 1. Dopant concentrations cannot be increased indefinitely because with increasing dopant concentration and with the ensuing decrease of the depletion layer thickness, doping fluctuations become more and more important.