CMOS Application of Schottky Source/Drain SOI MOSFET with Shallow Doped Extension

Abstract

The silicon-on-insulator metal-oxide-semiconductor field-effect transistor (SOI MOSFET) whose source/drain is composed of Schottky contacts and a shallow-doped extension is investigated. It is demonstrated that the incorporation of the shallow-doped extension into the Schottky source/drain can increase the current drive and reduce the leakage current under reverse bias for both n-channel and p-channel devices. The shallow doping is performed by implanting Sb for n-channel devices, and BF2 or Ga for p-channel devices. The effect of Schottky contacts on the floating body effect (FBE) is investigated by analyzing the lateral bipolar characteristics of these devices. By employing the shallow-doped extension, a complementary MOS (CMOS) of the Schottky source/drain can be fabricated using single metal (cobalt, in this work) silicide. The stability of CMOS operation with the proposed devices under a high supply voltage is demonstrated by comparing it with a conventional pn-junction SOI MOSFET. It is also demonstrated from the characteristics of the CMOS-inverter ring oscillator that the proposed device operates at speeds as high as or even higher than that of the conventional SOI MOSFET.