Gate Structures in Transistors and Method of Forming Same

A device comprising:

• a first nanostructure extending between a source region and a drain region;
• a second nanostructure over the first nanostructure;
• a gate dielectric over and around the first nanostructure and the second nanostructure;
• an aluminum residue over the gate dielectric;
• a work function metal (WFM) layer over the gate dielectric and the aluminum residue, the WFM layer comprising fluorine, a first portion of the WFM layer being disposed around the first nanostructure, a second portion of the WFM layer being disposed around the second nanostructure;
• and
• a conductive layer disposed over the WFM layer, a first portion of the conductive layer being disposed around the first nanostructure, a second portion of the conductive layer being disposed around the second nanostructure.

A transistor comprising:

• a first dielectric material disposed over a first nanostructure;
• a first metal residue disposed over the second dielectric material;
• a first conductive material disposed over the first dielectric material;
• a second conductive material disposed over the first conductive material;
• a third conductive material disposed over the second conductive material, the third conductive material having the same composition as the first conductive material;
• a second metal residue disposed over the third conductive material, the second metal residue having the same composition as the first metal residue;
• a second dielectric material disposed over the second metal residue, the second dielectric material having the same composition as the first dielectric material;
• a second nanostructure disposed over the second dielectric material.