1. Characterization of Nanoscale Dielectrics or What characterizes dielectrics needed for the 22 nm node? O. Engstrom 1, M. Lemme 2, P.Hurley 3 and S.Hall 4 1 Chalmers University of Technology 2 AMO GmbH 3 Tyndal Laboratories 4 Liverpool University

2. Questions at issue How long can HfO 2 be used? How to find the road to higher-k, higher offset dielectrics? Problems in connection with bulk and SOI

3. HfO 2

4. High-k Metal Gate AMO, Liverpool, Chalmers and Tyndall Ni Si HfO 2 Tyndall : e-beam evaporation Liverpool: MoCVD, ALD Chalmers: Reactive sputtering, ALD AMO: MBE & metallization

5. High-k Metal Gate SINANO Exchange: Tyndall  Chalmers Nov 2006 : Study of Bulk Defects in HfO 2 T ox (max/min) = 42.9Å/41.4Å  =0.15Å JV Dispersion: 65 sites 55umx55um (100)Si/SiO x (0.6nm)/HfO 2 (3.5nm)/Ni

6. (100)Si/SiO x /HfO 2 /TiN System Interface defects: Origin and Annealing p Sin Si P.K.Hurley, K. Cherkaoui, and A.W. Groenland “Electrically active interface defects in the (100)Si/SiOx/HfO2/TiN system: Origin, Instabilities and Passivation”, Invited paper: ECS, Cancun, Mexico, October 2006 SINANO Acknowledged HfO 2 by ALD

7. HfO 2 /TiN n channel MOSFETs Mobility degradation: Interface States D it = 4.0 x 10 10 cm -2 I CP (1 MHz) -I CP (1 kHz) Interface states do not limit mobility (D IT <5.0 x 10 10 cm -2 ) HfO 2 by ALD

8. HfO 2 /TiN n channel MOSFETs Mobility degradation Presented at EMRS Symposium L, 2006: SINANO acknowledged 100 1000 10000 100000 0100200300400 Temperature [K]  o [cm 2 /Vs]  sr cc  ph  o (fitting)  o (measured) Remote phonon scattering term limits mobility above temperature 50 K. Weber et al, Proc. ESSDERC, 2005, p. 379

9. Gavartin et al, JAP 97, 053704 (2005) Johansson et al, subm. JAP Oxide defects, ALD HfO 2

10. Mitrovic et al, manuscript submitted Hafnium silicate Spectroscopic ellipsometry Absorption constant [arb. units]

11. The road to higher k and higher band offset values

12. Scaling problem of the bulk MOSFET: Shorter channel length requires increased doping under the channel which requires higher capacitive coupling between gate and channel which in turn requires thinner gate insulator material

13. k=f( ) Clausius-Mosotti O. Engström, B. Raeissi, S. Hall, O. Buiu, M.C. Lemme, H.D.B. Gottlob, P.K. Hurley, K. Cherkaoui, Proc. ULIS, 2006, subm. To SSE

15. k=f( ) O. Engström, B. Raeissi, S. Hall, O. Buiu, M.C. Lemme, H.D.B. Gottlob, P.K. Hurley, K. Cherkaoui, Proc. ULIS, 2006, subm. To SSE

17. k=f( ) O. Engström, B. Raeissi, S. Hall, O. Buiu, M.C. Lemme, H.D.B. Gottlob, P.K. Hurley, K. Cherkaoui, Proc. ULIS, 2006, subm. To SSE

19. Offset value = f(heat of formation) O. Engström, B. Raeissi, S. Hall, O. Buiu, M.C. Lemme, H.D.B. Gottlob, P.K. Hurley, K. Cherkaoui, Proc. ULIS, 2006, subm. To SSE

20. The 22 nm node border Borders for the 22 nm LSTP node O. Engström, B. Raeissi, S. Hall, O. Buiu, M.C. Lemme, H.D.B. Gottlob, P.K. Hurley, K. Cherkaoui, Proc. ULIS, 2006, subm. To SSE

21. Gate insulators for SOI

22. H.D.B. Gottlob et al., IEEE EDL, Vol. 27, No. 10, October, 2006 ITRS targets for 2012 EOT given here for a quantum mechanical correction of CET by 0.3 nm Epitaxial Gd 2 O 3 with NiSi gate electrodes

23. Single gate Double gate From Risch, SSE 50, 527 (2006) SOI FD MOSFET LgLg x ”natural length”

24. E c [eV] x [nm] (a)  10 5 3 Source Drain x [nm] (b) Source Drain  Conduction band shape for an SOI FD DG MSFET

25. t Si [nm] L g / SiO 2 Gd 2 O 3 HfO 2 La 2 O 3 Silicon thickness for FD DG SOI MOSFETs in the 22 nm LSTP node

26. Sotomayor-Torres et al, Phys. Stat. Sol. 1, 2609 (2004) Donetti et al, JAP, 100, 013701 (2006) Uchida & Takagi, APL 82, 2916 (2003) Phonon and interface scattering in thin silicon layers Phonon modes Theory Mobility

27. Summary High-k for the 22 nm LSTP node Bulk: –So far only La 2 O 3, LaAlO 3 seem to pass SOI: –SiO 2 cannot be used neither for DG nor GAA –Probably HfO 2 can be used for GAA –For DG La 2 O 3 seems to be necessary, but Gd 2 O 3 may be an alternative Brask-lapp: Things may change!