Described herein are apparatuses, methods, and systems associated with a deep trench via in a three-dimensional (3D) integrated circuit (IC). The 3D IC may include a logic layer having an array of logic transistors. The 3D IC may further include one or more front-side interconnects on a front side of the 3D IC and one or more back-side interconnects on a back side of the 3D IC. The deep trench may be in the logic layer to conductively couple a front-side interconnect to a back-side interconnect. The deep trench via may be formed in a diffusion region or gate region of a dummy transistor in the logic layer. Other embodiments may be described and claimed.