SUBMICRON GAPS ON HIGH-MOBILITY SI-MOSFETS - A FLEXIBLE TOOL FOR ELECTRON-TRANSPORT STUDIES

We have fabricated high-mobility silicon metal-oxide-semiconductor fie ld-effect transistors containing gaps as narrow as 100 nm in the gate electrode. The submicron gaps are defined by electron beam lithography and by reactive ion etching. These devices can be used for a variety of fundamental studies of quantum transport. In particular, we show th at ballistic point contacts can be made in a Si-inversion layer.