Evidence for ballistic transport of two-dimensional electron gas at liquid-nitrogen temperatures in a silicon metal–oxide semiconductor field effect transistor with a neck in the middle

The transconductance of a silicon metal–oxide semiconductor field effect transistor with a neck in the middle was measured at liquid-nitrogen temperatures. The narrowest part of the gate with p+ isolations is 0.24 μm wide and about 0.2 μm long. The transconductance shows a peaked structure near the threshold voltage. The calculated transconductance based on the ballistic transport model of two-dimensional electron gas explains well the peaked structure.