Poly-insulator-poly capacitor and fabrication method thereof

A poly-insulator-poly (PIP) capacitor, comprising:

• a semiconductor substrate comprising a capacitor forming region;
• a first capacitor dielectric layer disposed on the capacitor forming region;
• a first poly electrode disposed on the first capacitor dielectric layer;
• a second capacitor dielectric layer disposed on the first poly electrode;
• a second poly electrode disposed on the second capacitor dielectric layer, wherein the first poly electrode comprises a contact portion that protrudes beyond an end surface of the second poly electrode;
• a third poly electrode disposed adjacent to a first sidewall of the second poly electrode;
• a third capacitor dielectric layer disposed between the third poly electrode and the second poly electrode;
• a fourth poly electrode disposed adjacent to a second sidewall of the second poly electrode that is opposite to the first sidewall;
• a hard mask layer capping the second poly electrode, and wherein a top surface of the hard mask layer is flush with a top surface of the fourth poly electrode;
• and
• a fourth capacitor dielectric layer disposed between the fourth poly electrode and the second poly electrode, wherein the first poly electrode, the third poly electrode, and the fourth poly electrode are electrically connected to an anode.