Possible observation of ballistic contact resistance in wide Si MOSFETs

In conclusion, using a comparison of our experimental data of R EXT versus N S and T to the ballistic FET theory, we have presented experimental evidence on the possible observation of ballistic contact resistance R B in wide-channel Si MOSFETs. Finally, we note that the ballistic contact resistance R B represents the ultimate limit of total series resistance R EXT [8]. This limit for (100) Si is ∼ 40 Ω.μm for NFETs and ∼ 70 Ω.μm for PFETs at N S = 1 × 10 13 cm -2. Furthermore, this limit of R EXT is ∼ 55 Ω.μm for III-V NFETs at N S = 1 × 10 13 cm 2 with isotropic effective mass m*/m 0 in the 0.02-0.1 range. The value of R B is slightly higher for III-V NFETs than that for Si NFETs because lower m* and lower valley degeneracy lead to lower number of conducting transverse modes. © 2012 IEEE.