Title :
Nitrogen profile control by plasma nitridation technique for poly-Si gate HfSiON CMOSFET with excellent interface property and ultra-low leakage current
Author :
Sekine, K. ; Inumiya, S. ; Sato, M. ; Kaneko, A. ; Eguchi, K. ; Tsunashima, Y.
Author_Institution :
Process & Manuf. Eng. Center, Toshiba Corp., Kanagawa, Japan
Abstract :
A comparative study of plasma and thermal nitridation of HfSiO was performed systematically. We found that over 15 atom% of nitrogen is necessary to obtain sufficient thermal stability and blocking of boron diffusion in a conventional polycrystalline Si gate CMOS process regardless of the nitridation method. However, we demonstrated, for the first time, that plasma nitridation has a great advantage for obtaining thinner equivalent oxide thickness, lower gate leakage current (J/sub g//J/sub g/SiO/sub 2/=1E-4 @ V/sub g/=V/sub fb/-1 V) and higher carrier mobility (/spl mu//sub eff///spl mu//sub eff/SiO/sub 2/=0.85 @ E/sub eff/=0.8 MV/cm for electron, /spl mu//sub eff///spl mu//sub eff/SiO/sub 2/=0.9 @ E/sub eff/=0.5 MV/cm for hole) due to nitridation of HfSiO film without nitridation of Si substrate, compared with thermal nitridation.
Keywords :
CMOS integrated circuits; MOS capacitors; MOSFET; carrier mobility; dielectric thin films; diffusion; hafnium compounds; integrated circuit testing; leakage currents; nitridation; plasma materials processing; silicon compounds; thermal stability; HfSiO-Si; HfSiON-Si; N/sub 2/; Si; Si substrate; boron diffusion blocking; carrier mobility; electron mobility; equivalent oxide thickness; gate leakage current; hole mobility; interface property; nitrogen profile control; nitrogen quantity; plasma nitridation technique; poly-Si gate HfSiON CMOSFET; thermal nitridation; thermal stability; ultra-low leakage current; Boron; CMOS process; CMOSFETs; Charge carrier processes; Electron mobility; Leakage current; Nitrogen; Plasma properties; Plasma stability; Thermal stability;
Conference_Titel :
Electron Devices Meeting, 2003. IEDM '03 Technical Digest. IEEE International
Conference_Location :
Washington, DC, USA
Print_ISBN :
0-7803-7872-5
DOI :
10.1109/IEDM.2003.1269176
