Gate structure of field effect transistor with footing

摘要

In some embodiments, an field effect transistor structure includes a first semiconductor structure and a gate structure. The first semiconductor structure includes a channel region, and a source region and a drain region. The source region and the drain region are formed on opposite ends of the channel region, respectively. The gate structure includes a central region and footing regions. The central region is formed over the first semiconductor structure. The footing regions are formed on opposite sides of the central region and along where the central region is adjacent to the first semiconductor structure.

主权项

1. A field effect transistor (FET) structure, comprising:
a substrate having a surface; a first semiconductor structure comprising:
a channel region, anda source region and a drain region formed on opposite ends of the channel region, respectively; and a gate structure comprising:
a central region formed over the surface and at least wrapping around three sides of the channel region, and footing regions formed on opposite sides of the central region and along where the central region is adjacent to the first semiconductor structure;wherein the central region includes a gate dielectric, a work function metal layer and a fill metal;wherein the gate dielectric and the work function metal layer extend to the footing regions, and the fill metal does not extend to the footing regions.