Using the atomic force microscope (AFM), we have fabricated a metal oxide semiconductor field‐effect transistor (MOSFET) on silicon with an effective channel length of 0.1 &mgr;m. The lithography at the gate level was performed with the scanning tip of the AFM. The gate was defined by electric‐field‐enhanced selective oxidation of the amorphous silicon gate electrode. The electrical characteristics were reasonable with a transconductance of 279 mS/mm and a threshold voltage of 0.55 V. ©1995 American Institute of Physics.