Title :
Ab Initio Modeling of Schottky-Barrier Height Tuning by Yttrium at Nickel Silicide/Silicon Interface
Author :
Geng, Li ; Magyari-Kope, Blanka ; Zhang, Zhiyong ; Nishi, Yoshio
Author_Institution :
Dept. of Microelectron., Xi´´an Jiaotong Univ., Xian
fDate :
7/1/2008 12:00:00 AM
Abstract :
The mechanism of Schottky-barrier height (SBH) tuning by yttrium (Y) segregated at nickel silicide (NiSi2)/silicon interface is investigated based on first-principle calculations. SBH modification can be explained by a new chemical structure that forms when Y atoms substitute silicon atoms near the interface. Silicon dangling bonds are saturated, leading to a new pinning-free interfacial structure. When other layers of Y atoms are segregated in , SBH for electrons can be reduced from 0.65 to 0.1 eV. The previously reported experimental phenomena can be explained by the calculations.
Keywords :
Schottky barriers; ab initio calculations; chemical structure; dangling bonds; elemental semiconductors; interface structure; nickel compounds; semiconductor-insulator boundaries; silicon; yttrium; NiSi2-Y-Si; Schottky-barrier height; ab initio modeling; chemical structure; first-principle calculations; nickel silicide-silicon interface; pinning-free interfacial structure; silicon dangling bonds; yttrium; Atomic layer deposition; Chemicals; Conductivity; Electrons; Nanoscale devices; Nickel; Schottky barriers; Silicides; Silicon; Yttrium; Nickel silicide $(hbox{NiSi}_{2})$; Schottky barrier (SB) modulation; segregation; yttrium (Y);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2008.2000647
