Forming an oxide volume within a fin

A device comprising:

• a substrate;
• a transistor coupled with the substrate, the transistor comprising:
• a fin coupled with the substrate, wherein the fin includes:
• a first side and a second side opposite the first side that are substantially parallel to a plane of the fin;
• a volume of oxide that extends through the fin from a first area on the first side of the fin to a second area on the second side of the fin, wherein the volume of oxide has at least one of a top surface or a bottom surface that is a non-planar surface between the first side and the second side of the fin, and wherein the volume of oxide has a vertical thickness at a center of the fin less than a vertical thickness at the first side of the fin and at the second side of the fin;
• and
• wherein the volume of oxide includes a selected one or more of:
• carbon atoms or fluorine atoms.