Gate end cap and boundary placement in transistor structures for N-metal oxide semiconductor (N-MOS) performance tuning

A device structure comprising:

• a first plurality of channel regions in a stack of a first transistor, each of the channel regions comprising a first sidewall and a second sidewall opposite of the first sidewall;
• a source region and a drain region coupled to opposite ends of the first plurality of channel regions;
• and
• a gate electrode between the source regions and the drain regions, the gate electrode comprising:
• a first layer comprising a first portion adjacent to the first sidewall and a second portion adjacent to a boundary sidewall spaced apart from the first sidewall, wherein the boundary sidewall comprises a dielectric material, and is a first distance away from a first gate dielectric layer that is adjacent to the first sidewall;
• and
• a second layer directly adjacent to the first layer, and occupying a space between the first and second portions of the first layer;
• wherein:
• the first layer is a first workfunction material having a first composition associated with a first workfunction, wherein the first layer comprises a third portion below the second layer, wherein the third portion is contiguous with the first and second portions;
• the first portion of the first layer is of a first lateral thickness from the first sidewall;
• the second portion of the first layer is directly adjacent to a second gate electrode of a second transistor further comprising a second gate dielectric layer and a second plurality of channel regions in a stack;
• the second layer is a second workfunction material having a second composition associated with a second workfunction, and is of a second lateral thickness from the first sidewall;
• a ratio of the second lateral thickness to the first lateral thickness is less than three;
• the first sidewalls of the first plurality of channel regions are laterally spaced apart by a distance from first sidewalls of the second plurality of channel regions;
• and
• the second gate electrode is of a fourth lateral thickness equal to a difference between the distance minus a sum of the first lateral thickness, the second lateral thickness, a third lateral thickness of the second portion of the first layer, a lateral thickness of the first gate dielectric layer, and a lateral thickness of the second gate dielectric layer.