Schottky barrier source/drain N-MOSFET using ytterbium silicide

Abstract

A method of fabricating an N-type Schottky barrier Source/Drain Transistor (N-SSDT) with ytterbium silicide (YbSi 2-x ) for source and drain is presented. The fabrication of YbSi 2-x is compatible with the normal CMOS process but ultra-high vacuum, which is required for ErSi 2-x fabrication, is not needed here. To prevent oxidation of ytterbium during ex situ annealing and to improve the film quality, a suitable capping layer stack has been developed.

1 . A method to form an N-type Schottky barrier source/drain MOSFET, comprising:
 providing, on a layer of P-type silicon, a gate structure having a gate electrode on a layer of gate insulation; and   forming source and drain regions, that comprise ytterbium silicide, on opposing sides of said gate electrode.   
   
   
       2 . The method described in  claim 1  wherein said layer of gate insulation is hafnium oxide. 
   
   
       3 . The method described in  claim 1  wherein said gate electrode is hafnium nitride.