Scanning probe lithography using a cantilever with integrated transistor for on-chip control of the exposing current

Scanning probe lithography uses electrons held emitted from a micromachined probe tip to expose organic polymer resists. The exposed pattern dimension is set by the electron dose delivered to the resist and can be controlled down to <30 nm. We have integrated a metal-oxide-semiconductor held-effect transistor (MOSFET) onto the cantilever chip to act as a current source to control the electron exposure dose from the tip. The silicon cantilever and tip form the drain of the MOSFET. In the saturation regime, the transistor acts as a voltage-controlled current source. A low voltage signal to the t ransistor gate sets the exposure dose. We describe the design and fabricati on of this device and demonstrate that the integrated transistor can be use d as the sole current-control electronics for uniform high-resolution litho graphy, eliminating the need for external circuitry. (C) 1999 American Vacu um Society. [S0734-211X(99)07006-7].