Modulation and Extraction of Schottky Barrier Height for Advanced Source/Drain Contact

Abstract

As the device geometry dramatically shrinks, the silicice/Si contact resistance on source/drain regions is dominating the parasitic resistance and degrading the device characteristics. To lower the contact resistance one of the effective methods is to lower the Schottky barrier height (SBH) of silicide/Si contact on source/drain regions. In this paper the influence of alloy addition on Ni silicidation and the corresponding SBH, such as Ni(Y), Ni(Yb) and Ni(Al) is investigated. Besides, as one of the rare earth (RE) silicides, YbSi2-x is a promising contact material in conventional n-channel metal-oxide-semiconductor field effect transistors (nMOSFET) and n-channel Schottky barrier source/drain FETs. In this paper the oxidation suppression and pinhole-free YbSi2-x film preparation will be reported. To extract the low SBH, a new method based on admittance measurement will also be introduced.