Modulating Electron Energy Barrier at Metal/Semiconductor and Metal/Insulator Contacts with Thin Interfacial Layer

The electron energy barrier at metal/semiconductor and metal/insulator contacts is one of the crucial elements determining the operational characteristics of electronic and optoelectronic devices. A metal/semiconductor contact is the gateway of charge carrier transport into and out of the active area in all semiconductor devices including Schottky diodes, PN diodes, Bipolar transistors, and field effect transistors. The charge carrier transport through the contact, regulated mainly by the interface energy barrier, is directly tied to the functionality of device such as rectification and its power consumption manifesting the contact resistance. A metal/insulator contact takes part in constructing the metal/oxide/semiconductor (MOS) structure adopted in MOS capacitor and MOS field effect transistor (MOSFET). In this case, the interface energy barrier makes a dominant influence on the threshold voltage at which the inversion channel is induced on the semiconductor side.