Method of fabricating a semiconductor device

A method of fabricating an integrated circuit, comprising:

• identifying neighboring gate structures having different gate lengths, the neighboring gate structures being part of a first layout including gate structures and diffusion regions, and the neighboring gate structures including a first gate structure having a first gate length and a second gate structure having a second gate length different from the first gate length;
• modifying the first layout resulting in a second layout comprising:
• inserting a dummy device between the first gate structure and the second gate structure;
• extending a first diffusion region of the first gate structure to the dummy device, the first diffusion region being shared by the dummy device and the first gate structure;
• and
• performing a design rule check on the second layout, the performing the design rule check comprises considering the sharing of the first diffusion region by the dummy device and the first gate structure as complying with a design rule of the design rule check;
• and
• fabricating the integrated circuit based on the second layout.

A method of fabricating an integrated circuit, comprising:

• identifying a first device, the first device being part of a first layout including gate structures and diffusion regions, the first device having a first gate structure and an irregular diffusion region, the first device being adjacent to a second device having a second gate structure;
• modifying the first layout resulting in a second layout comprising:
• inserting a dummy device between the first gate structure and the second gate structure, wherein a first diffusion region is shared by the dummy device and the first gate structure, a second diffusion region is shared by the dummy device and the second gate structure, the first diffusion region or the second diffusion region has a rectangular shape, and the irregular diffusion region has a non-rectangular shape;
• and
• performing a design rule check on the second layout, the performing the design rule check comprises considering the sharing of the first diffusion region by the dummy device and the first gate structure or the sharing of the second diffusion region by the dummy device and the second gate structure as complying with a design rule of the design rule check;
• and
• fabricating the integrated circuit based on the second layout.