Modulation of PtSi Work Function by Alloying with Low Work Function Metal

Jun GAO  Jumpei ISHIKAWA  Shun-ichiro OHMI  

IEICE TRANSACTIONS on Electronics   Vol.E94-C   No.5   pp.775-779
Publication Date: 2011/05/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E94.C.775
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Fundamentals and Applications of Advanced Semiconductor Devices)
PtSi,  monosilicide,  alloy,  work function,  SWC-anneal,  

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In order to reduce PtSi Schottky barrier height (SBH) for electron, we investigated modulation of PtSi work function by alloying with low work function metal, such as Hf (3.9 eV) and Yb (2.7 eV). Pt (10-20 nm)/Hf, Yb (0-10 nm)/n-Si(100) stacked structures were in-situ deposited at room temperature by RF magnetron sputtering method. In case of PtxHf1 - xSi formed at 400/60 min annealing in N2, SBH for electron was reduced from 0.85 eV to 0.53 eV with Hf thickness without increase of sheet resistance. Yb incorporation also affected the SBH modulation, however, the sheet resistance increased with increase of Yb thickness.