Title :
Dual work function metal gates using full nickel silicidation of doped poly-Si
Author :
Sim, J.H. ; Wen, H.C. ; Lu, J.P. ; Kwong, D.L.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Texas, Austin, TX, USA
Abstract :
This paper investigates the work function adjustment on fully silicided (FUSI) NiSi metal gates for dual-gate CMOS, and how it is effected by the poly-Si dopants. By comparing FUSI on As-, B-, and undoped poly-Si using the same p-Si substrates, it is shown that both As and B influence the work function of NiSi FUSI gate significantly, with As showing more effects than B possibly due to more As pile-up at the NiSi-SiO/sub 2/ interface. No degradations on the underlying gate dielectrics are observed in terms of interface state density (D/sub it/), fixed oxide charges, leakage current, and breakdown voltage, suggesting that NiSi FUSI is compatible with dual-gate CMOS processing.
Keywords :
CMOS integrated circuits; arsenic; boron; elemental semiconductors; integrated circuit metallisation; interface states; leakage currents; nickel compounds; semiconductor device breakdown; silicon; work function; NiSi-SiO/sub 2/; NiSi-SiO/sub 2/ interface; Si; Si:As; Si:B; breakdown voltage; doped poly-Si; dual work function metal gates; dual-gate CMOS; fixed oxide charges; fully silicided NiSi metal gates; interface state density; leakage current; nickel silicidation; p-Si substrates; poly-Si dopants; polysilicon; work function adjustment; CMOS process; CMOS technology; Capacitors; Degradation; Dielectric substrates; Interface states; Leakage current; MOS devices; Nickel; Silicidation;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2003.817372
