Solid-State Electronics, Vol.48, No.2, 335-338, 2004
Negative Schottky barrier between titanium and n-type Si(001) for low-resistance ohmic contacts
A metal-semiconductor contact should have a negative Schottky barrier if the metal has a work function less than the electron affinity of the semiconductor. Such a contact would behave ohmically with a low internal resistance. In reality, the electronic states on the semiconductor surface pin the surface Fermi level and make almost all the metals to show a positive Schottky barrier. By eliminating surface states on Si(001) with a monolayer of selenium, ohmic contacts with a negative Schottky barrier are demonstrated between titanium and n-type Si(001). These contacts are found to be thermally stable up to 400 degreesC. (C) 2003 Elsevier Ltd. All rights reserved.