Transistor gate metal with laterally graduated work function

摘要

Semiconductor device(s) including a transistor with a gate electrode having a work function monotonically graduating across the gate electrode length, and method(s) to fabricate such a device. In embodiments, a gate metal work function is graduated between source and drain edges of the gate electrode for improved high voltage performance. In embodiments, thickness of a gate metal graduates from a non-zero value at the source edge to a greater thickness at the drain edge. In further embodiments, a high voltage transistor with graduated gate metal thickness is integrated with another transistor employing a gate electrode metal of nominal thickness. In embodiments, a method of fabricating a semiconductor device includes graduating a gate metal thickness between a source end and drain end by non-uniformly recessing the first gate metal within the first opening relative to the surrounding dielectric.