A transistor channel profile structure may be improved to provide better transistor circuits performance. In one example, a transistor circuit may include different fin profiles for the NMOS transistors and the PMOS transistors, such as the NMOS fins are thicker than the PMOS fins or the NMOS fin has a straight vertical surface and the PMOS fin has a notch at a fin bottom region. In still another example, a transistor circuit may include different nano-sheet profiles for a NMOS GAA device and a PMOS GAA device where the NMOS nano-sheet is thicker than the PMOS nano-sheet. Such configurations optimize the NMOS and the PMOS transistors with the NMOS having a low channel resistance while the PMOS has a lower short channel effect.