Gating a two dimensional electron gas in silicon using a metallic single electron transistor

A wealth of physical phenomena has been observed in two dimensional electron systems such as the silicon metal-oxide-semiconductor field effect transistor (MOSFET). Due to impurities and interface states, a silicon MOSFET channel is usually imperfect. A single electron transistor (SET) close to the channel could provide a useful probe of these imperfections and of the channel behavior. We have incorporated an Al/AlO$_{x}$/Al SET as the top gate of a conventional MOSFET. The SET is fabricated with standard electron-beam lithography and double-angle thermal evaporation. A thermally grown SiO$_{2}$ barrier layer about 20 nm thick isolates the SET from the lightly p-doped MOSFET channel beneath. The drain and source of the MOSFET are heavily n-doped and conduct at cryogenic temperatures. A nearby surface metal gate is used to modulate the width of the channel right beneath the SET island. Near the pinch off regime we expect to see a correlation between fluctuations in the current through the SET and fluctuations in the current of the MOSFET channel. We will present preliminary data from these devices.