Described herein are IC devices that include transistors with contacts to one of the source/drain (S/D) regions being on the front side of the transistors and contacts to the other one of the S/D regions being on the back side of the transistors (i.e., “back-side contacts”). Using transistors with one front-side and one back-side S/D contacts provides advantages and enables unique architectures that were not possible with conventional front-end-of-line transistors with both S/D contacts being on one side.