Effective Schottky barrier lowering of Ni silicide/p-Si(100) using an ytterbium confinement structure for high performance n-type MOSFETs

Abstract

Effective Schottky barrier lowering of Ni silicide/p-Si(100) using an ytterbium confinement structure for high performance n-type MOSFETs Author links open overlay panelKeng-HuiShen a Szu-HungChen b Wei-TingLiu a Bao-HsienWu a Lih-JuannChen a Show more https://doi.org/10.1016/j.matdes.2016.11.084 Get rights and content Highlights • The insertion of Ti layer effectively suppresses Yb out-diffusion and prevents the Yb from oxidation during silicidation. • Yb atoms are confined by the inserted Ti layer and react with both Ni and Si to form Yb-Ni silicide. • The confinement leads the SBH of the system to a 0.02 and 0.025 eV lowering at 500 and 600 °C, respectively. • The RE metal confinement structure provides a CMOS compatible approach for further SBH engineering and technology nodes. Abstract A simple but effective rare earth metal (RE) confinement structure is demonstrated to suppress surface accumulation of Yb generally encountered in the RE metal incorporated Ni silicide system. The confinement structure is realized by inserting a Ti diffusion barrier layer between Yb and Ni layers. Yb atoms can be constrained in a specified reaction region during silicidation as evidenced by Auger electron spectroscopy and cross-section transmission electron microscopy analysis. The RE metal confinement structure provides a complementary metal-oxide-semiconductor compatible approach for further Schottky barrierheight engineering and is a promising method for future technology nodes. Graphical abstract 1. Download high-res image (272KB) 2. Download full-size image 

Advanced process and electron device technology

“…The segregated dopants result in a strong energy band bending, which shifts the Fermi level toward the band edge. For the alloying method, Ni alloying with metals of different work functions is used to tune the SBH [43] . Essentially, these methods can work synergistically instead of independently to deepen the Fermi level.…”