Disclosed are embodiments of a field effect transistor that incorporates
an elongated semiconductor body with a spiral-shaped center channel
region wrapped one or more times around a gate and with ends that extend
outward from the center region in opposite directions away from the gate.
Source/drain regions are formed in the end regions by either doping the
end regions or by biasing a back gate to impart a preselected Fermi
potential on the end regions. This disclosed structure allows the
transistor size to be scaled without decreasing the effective channel
length to the point where deleterious short-channel effects are
exhibited. It further allows the transistor size to be scaled while also
allowing the effective channel length to be selectively increased (e.g.,
by increasing the number of times the channel wraps around the gate).
Also, disclosed are embodiments of an associated method of forming the
transistor.