A field effect transistor (FET) cell structure of an integrated circuit (IC) is provided. The FET cell structure includes first and second adjacent cells. Each of the first and second adjacent cells spans a first layer and a second layer. The second layer is vertically stacked on the first layer. The first cell includes n-doped FETs (NFETs) on one of the first and second layers and p-doped FETs (PFETs) on another of the first and second layers. The second cell includes at least one of a number of NFETs on the one of the first and second layers differing from a number of the NFETs in the first cell and a number of PFETs on the another of the first and second layers differing from a number of the PFETs in the first cell.