PROCESSES FOR THE FABRICATION OF FIELD EFFECT TRANSISTORS

摘要

A field effect transistor having a narrow control gate (7) located beneath an overlap gate (9) is fabricated by forming a trench having a vertical sidewall in a gate oxide region over the channel region of the device, vapour depositing metal in the trench in the gate oxide region at such an angle that a thicker metal coating is formed on the vertical sidewall than over the remainder of the trench and then etching away the deposited metal in the trench to leave only a metal coating on the sidewall to serve as the narrow control gate (7).