Amorphized subfins using backside implantation

Abstract

Techniques to form semiconductor devices that include subfins that are at least partially amorphized are described. A backside dopant implantation process using dopants (e.g., germanium) may be used to create amorphous semiconductor material in the subfins. In an example, a semiconductor device includes a gate structure around or otherwise on a semiconductor region formed from a fin of semiconductor material. The fin includes a subfin laterally adjacent to a dielectric fill. A backside ion implantation process may be used to implant dopants such as Ge into the subfin and consequently form an amorphized portion of the subfin. In some examples, the amorphized portion is under the gate structure and laterally between a source region and a drain region. The amorphized portion may extend from a bottom surface of the subfin to just under the gate structure, and in some cases, leave a crystalline portion of subfin below the gate structure.