(23)Masi, M. Cavallotti. C: Carra, S. In Silicon-Bas (27) Javey. A: Nam, S; Friedman, R.S.; Yan, H; Lieber, C M. Nano Devices: Nalwa, H. S. Eds: Academic Press: San Diego, 200 Let.2007,7,773. (28) The SiNWs were transferred to the oxide surface of doped (resistivity (24)Roenigk, K F; Jensen, K. F: Carr, R. w.J. Phys. Chem. 1987, 91, 0.005 Q2cm) silicon substrates(Silicon Valley Microelectronics, Inc. 5732. San Jose, CA), multiple source-drain electrodes were defined by (25) SiNWs were synthesized at 390-410C using well-dispersed gold electron beam lithography, and then Ni contacts (70 nm thick)were nanoclusters(10-80 nm diameter) as catalysts, H2 as carrie deposited by thermal evaporation. The contacts were annealed at 280 (10 cm at standard temperature and pressure, STM min min in forming gas (10% H2 in H and Si2H6(3 STM min-i)as reactant source at 10 torr. Boron (29)(a)Jin, S: Whang, D: McAlpine, M. C; Friedman, R. S: Wu, Y. doped p-type SiNWs were synthesized using 100 ppm B2H6 as Lieber, C. M. Nano Lett. 2004. 4. 915(b)Hong. W.K.: Kim, B..J oping source with a Si2Hs/B2H6 ratio of 105-2 x 105: 1(Si/B Kim. T -W: Jo. G. Song. S: Kwon, S.-S: Yoon. A: Stach, E. A Lee, T Colloid Surf, A 2008, 313, 378 (26) Yang, C. Zhong, Z: Lieber, C. M. Science 2005, 310, 130 NL802063Q Nano Let., Vol. 8. No. 9, 2008(23) Masi, M.; Cavallotti, C.; Carra`, S. In Silicon-Based Materials and DeVices; Nalwa, H. S., Eds.; Academic Press: San Diego, 2001; Ch. 4. (24) Roenigk, K. F.; Jensen, K. F.; Carr, R. W. J. Phys. Chem. 1987, 91, 5732. (25) SiNWs were synthesized at 390-410 °C using well-dispersed gold nanoclusters (10-80 nm diameter) as catalysts, H2 as carrier gas (10 cm3 at standard temperature and pressure, STM min-1) and Si2H6 (3 STM min-1) as reactant source at 10 torr. Boron￾doped p-type SiNWs were synthesized using 100 ppm B2H6 as doping source with a Si2H6/B2H6 ratio of 105-2 × 105:1 (Si/B ) 105-2 × 105:1). (26) Yang, C.; Zhong, Z.; Lieber, C. M. Science 2005, 310, 1304. (27) Javey, A.; Nam, S.; Friedman, R. S.; Yan, H.; Lieber, C. M. Nano Lett. 2007, 7, 773. (28) The SiNWs were transferred to the oxide surface of doped (resistivity <0.005 Ω·cm) silicon substrates (Silicon Valley Microelectronics, Inc., San Jose, CA), multiple source-drain electrodes were defined by electron beam lithography, and then Ni contacts (70 nm thick) were deposited by thermal evaporation. The contacts were annealed at 280 °C for 1 min in forming gas (10% H2 in He). (29) (a) Jin, S.; Whang, D.; McAlpine, M. C.; Friedman, R. S.; Wu, Y.; Lieber, C. M. Nano Lett. 2004, 4, 915. (b) Hong, W.-K.; Kim, B.-J.; Kim, T.-W.; Jo, G.; Song, S.; Kwon, S.-S.; Yoon, A.; Stach, E. A.; Lee, T. Colloid. Surf., A 2008, 313, 378. NL802063Q Nano Lett., Vol. 8, No. 9, 2008 3009