Some aspects relate to a FinFET that includes a semiconductor fin disposed over a semiconductor substrate and extending laterally between a source region and a drain region. A shallow trench isolation (STI) region laterally surrounds a lower portion of the semiconductor fin, and an upper portion of the semiconductor fin remains above the STI region. A gate electrode traverses over the semiconductor fin to define a channel region in the semiconductor fin under the conductive gate electrode. A punch-through blocking region can extend between the source region and the channel region in the lower portion of the semiconductor fin. A drain extension region can extend between the drain region and the channel region in the lower portion of the semiconductor fin. Other devices and methods are also disclosed.