Semiconductor structures are provided. The semiconductor structure includes a plurality of gate structures extending in a first direction formed over a substrate and a contact formed adjacent to the gate structures over the substrate. The semiconductor structure further includes a plurality of metal layers formed over the gate structures. In addition, some of the metal layers include metal lines extending in the first direction, and some of the metal layers include metal lines extending in a second direction substantially perpendicular to the first direction. Furthermore, the gate structures follow the following equation: 0.2 ⁢ ⁢ P gate ⁢ ⁢ min + 0.35 ⁢ ⁢ L gate ⁢ ⁢ min + 0.3 ⁢ ⁢ H gate ⁢ ⁢ min - 20 0.2 ⁢ ⁢ L gate ⁢ ⁢ min + 0.8 ⁢ ⁢ H gate ⁢ ⁢ min - 5 × 0.3 ⁢ ⁢ L gate ⁢ ⁢ min + 0.3 ⁢ ⁢ H gate ⁢ ⁢ min + 5 38 ≤ 0.32 Pgate min is the minimum value among gate pitches of the gate structures. Lgate min is the minimum value among gate lengths of the gate structures. Hgate min is the minimum value among gate heights of the gate structures.