A Study of the Dependence of Effective Schottky Barrier Height in Ni Silicide/n-Si on the Thickness of the Antimony Interlayer for High Performance n-channel MOSFETs

Abstract

Abstract-In this paper, the effective electron Schottky barrier height (Ф Bn ) of the Ni silicide/nsilicon (100) interface was studied in accordance with different thicknesses of the antimony (Sb) interlayer for high performance n-channel MOSFETs. The Sb interlayers, varying its thickness from 2 nm to 10 nm, were deposited by radio frequency (RF) sputtering on lightly doped n-type Si (100), followed by the in situ deposition of Ni/TiN (15/10 nm). It is found that the sample with a thicker Sb interlayer shows stronger ohmic characteristics than the control sample without the Sb interlayer. These results show that the effective Ф Bn is considerably lowered by the influence of the Sb interlayer. However, the current level difference between Schottky diodes fabricated with Sb/Ni/TiN (8/15/10 nm) and Sb/Ni/TiN (10/15/10 nm) structures is almost same. Therefore, considering the process time and cost, it can be said that the optimal thickness of the Sb interlayer is 8 nm. The effective Ф Bn of 0.076 eV was achieved for the Schottky diode with Sb/Ni/TiN (8/15/10 nm) structure. Therefore, this technology is suitable for high performance n-channel MOSFETs.Index Terms-Nckel silicide, antimony interlayer, Schottky diode, effective Schottky barrier height, nchannel MOSFETs