Nanoribbon stacks without dielectric protection caps for top nanoribbons

An integrated circuit (IC) structure, comprising:

• a support;
• a stack of nanoribbons over the support;
• an opening over a top nanoribbon of the stack;
• and
• a gate electrode material in the opening,
• wherein:
• the opening has a first portion, a second portion, and a third portion,
• the second portion is between the first portion and the third portion, and
• a width of a portion of the gate electrode material in the second portion is smaller than a width of a portion of the gate electrode material in the first portion.

A process of making an integrated circuit (IC) structure, the process comprising:

• providing a stack of nanoribbons over a base;
• and
• providing an opening over a top nanoribbon of the stack, the opening comprising a first portion, a second portion, and a third portion, wherein:
• the first portion is closer to the base than the second portion,
• the second portion is closer to the base than the third portion, and
• a gate insulator is on sidewalls of the first portion and the third portion and is absent from sidewalls of the second portion.