FinFET CMOS device including single diffusion break in each of NMOS and PMOS regions

A semiconductor device, comprising:

• a first MOS region comprises a PMOS region and a second MOS region comprises a NMOS region on a substrate:
• a first fin-shaped structure on the PMOS region;
• a first single diffusion break (SDB) structure in the first fin-shaped structure;
• a first gate structure on the first SDB structure;
• a second gate structure on the first fin-shaped structure, wherein the first gate structure and the second gate structure are of different materials and the first gate structure disposed directly on top of the first SDB structure is a polysilicon gate while the second gate structure disposed on the first fin-shaped structure is a metal gate in the PMOS region of the first MOS region;
• a second fin-shaped structure on the NMOS region;
• a second SDB structure in the second fin-shaped structure;
• and
• a third gate structure on the second SDB structure and a fourth gate structure on the second fin-shaped structure, wherein the third gate structure and the fourth gate structure are of same material, the third gate structure disposed directly on top of the second SDB structure is a metal gate and the fourth gate structure disposed on the second fin-shaped structure is also a metal gate in the NMOS region of the second MOS region, wherein each of the metal gates on the PMOS region and the NMOS region is transformed from a dummy gate, while the polysilicon gate is an active gate made of polysilicon.