Backside contact placeholder formation with improved process control

An apparatus, comprising:

• a frontside metallization layer and a backside metallization layer;
• a transistor structure comprising one or more semiconductor structures between and coupling first and second impurity doped regions, and a gate electrode adjacent the semiconductor structures, wherein the transistor structure is between the frontside metallization layer and a backside metallization layer;
• a backside contact coupled to the first impurity doped region and the backside metallization layer;
• and
• a metal structure between the second impurity doped region and the backside metallization layer, the metal structure in contact with the second impurity doped region and decoupled from the backside metallization layer.

A method, comprising:

• forming an opening adjacent to expose a stack of nanoribbons, wherein the stack of nanoribbons is over a substrate and wherein the opening extends into the substrate;
• filling the opening with an insulator material;
• recessing the insulator material to a position below the stack of nanoribbons to form a template comprising the insulator material;
• replacing the template comprising the insulator material with a placeholder metal;
• growing an impurity doped region from the exposed stack of nanoribbons, the impurity doped region on the placeholder metal;
• and
• replacing the placeholder metal with a backside contact.