Patent attributes
A semiconductor device includes an N-type fin-like field effect, a P-type fin-like field effect transistor, a shallow trench isolation (STI) structure, a first interlayer dielectric (ILD) layer, and a second ILD layer. The N-type fin-like field effect transistor includes a first semiconductor fin, a gate structure across the first semiconductor fin, and a first source/drain feature in contact with the first semiconductor fin. The P-type fin-like field effect transistor includes a second semiconductor fin, the gate structure across the second semiconductor fin, and a second source/drain feature in contact with the second semiconductor fin. The structure surrounds the first and second semiconductor fins. The first interlayer dielectric (ILD) layer covers the first source/drain feature. The second ILD layer covers the second source/drain feature, wherein a porosity of the second ILD layer is greater than a porosity of the first ILD layer.