An at least penta-sided-channel type of FinFET transistor may include: a base; a semiconductor body formed on the base, the body being arranged in a long dimension to have source/drain regions sandwiching a channel region, at least the channel, in cross-section transverse to the long dimension, having at least five planar surfaces above the base; a gate insulator on the channel region of the body; and a gate electrode formed on the gate insulator.