Method for fabricating a MOSFET having a very small channel length

摘要

A gate layer stack formed with at least two layers is firstly patterned anisotropically and then the lower layer is etched. An isotropic, preferably selective etching step effects a lateral undercutting, i.e. removal of the lower layer as far as the predetermined channel length. This allows a T-gate transistor with a very short channel length to be fabricated dimensionally accurately, in a simple manner and cost-effectively. Its electrical switching properties are better than those of other T-gate transistors formed by conventional methods.