Title :
Band-Edge High-Performance High-k/Metal Gate n-MOSFETs Using Cap Layers Containing Group IIA and IIIB Elements with Gate-First Processing for 45 nm and Beyond
Author :
Narayanan, Vijaykrishnan ; Paruchuri, V.K. ; Bojarczuk, N.A. ; Linder, B.P. ; Doris, B. ; Kim, You Ho ; Zafar, Sameena ; Stathis, J. ; Brown, Shannon ; Arnold, Jonathan ; Copel, M. ; Steen, M. ; Cartier, E. ; Callegari, A. ; Jamison, P. ; Locquet, J.-P. ;
Author_Institution :
IBM Semicond. R&D Center, T. J. Watson Res. Center, Yorktown Heights, NY
Abstract :
We have fabricated electrically reliable band-edge (BE) high-k/metal nMOSFETs stable to 1000degC, that exhibit the highest mobility (203 cm2/Vs @ 1MV/cm) at the thinnest Tinv (1.4 nm) reported to date. These stacks are formed by capping HfO2 with ultra-thin layers containing strongly electropositive gp. IIA and IIIB elements (e.g. Mg and La), prior to deposition of the TiN/Poly-Si electrode stack, in a conventional gate-first flow. Increasing the cap thickness tunes the Vt/V fb from a midgap position to BE while maintaining high mobility and good PBTI. The addition of La can enhance the effective k value of the dielectric stack, resulting in EOTs < 1nm. Short channel devices with band edge characteristics are demonstrated down to 60 nm. Finally, possible mechanisms to explain the nFET Vt shift are discussed
Keywords :
MOSFET; electron mobility; hafnium compounds; high-k dielectric thin films; lanthanum; metal-insulator boundaries; nanotechnology; 1000 C; 45 nm; Group IIA elements; Group IIIB elements; HfO2-TiN-Si; band-edge MOSFET; cap layers; dielectric stack; electron mobility; midgap position; nFET; short channel devices; Channel bank filters; Electrodes; Electron mobility; Hafnium oxide; High K dielectric materials; High-K gate dielectrics; Jamming; MOSFET circuits; Research and development; Tin;
Conference_Titel :
VLSI Technology, 2006. Digest of Technical Papers. 2006 Symposium on
Conference_Location :
Honolulu, HI
Print_ISBN :
1-4244-0005-8
DOI :
10.1109/VLSIT.2006.1705275
