We present an experimental study of effective carrier mobility (mu(eff)) of multi-fin-type double-gate metal-oxide-semiconductor field-effect transistors (FinFETs) with a (111) channel surface fabricated by orientation-dependent Wet etching. The peak values of the obtained mu(eff) of electrons and holes are approximately 300 and 160 cm(2)/(V s), respectively, which are close to those in (111) bulk metal-oxide-semiconductor field-effect transistors (MOSFETs). Moreover, the effective electric field (E-eff) dependence of the mu(eff) of electrons and holes shows a good agreement with the mobility universal curves of (111) bulk MOSFETs. These results indicate that the quality and channel surface roughness of Si-fins by orientation-dependent wet etching are excellent. The obtained results of mu(eff) are very useful for the modeling and design of FinFET-complementary metal-oxide-semiconductor (CMOS) circuits and the developed wet etching technique is very attractive in the fabrication of ultrathin and high-quality Si-fin channels.