Semiconductor Device Fabrication Method and Structure

摘要

A semiconductor device, and a method of fabrication, is introduced. In an embodiment, a dummy gate stack is formed on a substrate. Lightly-doped source/drain regions and highly-doped source/drain regions are formed in the substrate on either sides of the dummy gate stack. An inter-layer dielectric (ILD) layer is formed over the substrate. Subsequently, the dummy gate stack is removed and a gate stack is formed in an opening in the ILD layer. The gate stack is formed by forming an interfacial layer in the opening of the ILD layer, forming a gate dielectric layer over the interfacial layer, forming a work function metal layer over the gate dielectric layer, and forming one or more gate electrode layers over the work function metal layer. Contacts are formed in the ILD layer and one or more metallization layers are formed over the ILD layer.

主权项

1. A semiconductor device comprising:
a substrate; a first transistor on the substrate, the first transistor comprising:
a first channel, the first channel having a first length; anda first gate, the first gate having a first number of conductive layers, a topmost conductive layer of the first number of conductive layers comprising a first conductive material; and a second transistor on the substrate, the second transistor comprising:
a second channel, the second channel having a second length; anda second gate, the second gate having a second number of conductive layers, the second number being larger than the first number, a conductive layer below a topmost conductive layer of the second number of conductive layers comprising the first conductive material.