Process of planarizing crown capacitor for integrated circuit

Abstract

A method for fabricating an integrated circuit having a cell area and a peripheral circuit area in a semiconductor substrate is disclosed. First, a memory device and a transistor are formed within the cell area and the peripheral circuit area, respectively, wherein the memory device has a doped region formed in the semiconductor substrate. Then, a first insulating layer is formed to overlie the cell area and the peripheral circuit area, and thereafter patterned to be a trench over the doped region and a recess in the peripheral circuit area. Next, the first insulating layer is patterned through the trench to form a contact window, and a landing plug is filled into the contact window in contact with the doped region. Subsequently, a second insulating layer and a third insulating layer are sequentially formed to overlie the cell area and the peripheral circuit area, and then patterned to form an opening over the doped region. Next, a first conductive layer is formed on the bottom and sidewall of the opening in contact with the landing plug. Then, the third insulating layer in the cell area is removed by a planarization process, and the second insulating layer in the cell area is thereafter removed. Finally, a dielectric layer and a second conductive layer are sequentially formed over the first conductive layer.