A method of fabricating a metal-insulator-metal capacitor includes providing a dielectric layer. The dielectric layer is etched to form a first hole including a first convex profile bulging into the dielectric layer. Subsequently, the dielectric layer is etched to form a second hole including a second convex profile bulging into the dielectric layer. A first metal layer is formed to conformally cover the capacitor trench. An insulating layer is formed to cover the first metal layer. Finally, a second metal layer is formed covering the insulating layer.