A method of forming an integrated circuit including forming a first diffusion area and a second diffusion area on a substrate, wherein the first diffusion area is configured for a first type transistor, the second diffusion area is configured for a second type transistor. The method further includes forming first source and drain regions in the first diffusion area. The method further includes forming second source and drain regions in the second diffusion area. The method further includes forming a gate electrode extending across the first diffusion area and the second diffusion area. The method further includes forming a first metallic layer, a second metallic layer, and a third metallic layer. The first metallic layer is electrically coupled with the first source region. The second metallic layer is electrically coupled with the first and second drain regions. The third metallic layer is electrically coupled with the second source region.