Semiconductor device and method of fabricating the same

A method of fabricating a semiconductor device, comprising:

• providing a landing pad;
• alternatingly forming supporting layers and oxide layers over the landing pad;
• patterning the supporting layers and the oxide layers to form a cylindrical opening, wherein the supporting layers are patterned to form a supporting structure;
• forming a plurality of island structures over the supporting structure and the oxide layers, and on sidewalls of the cylindrical opening;
• conformally forming a conductive layer over the plurality of island structures and within the cylindrical opening;
• patterning the conductive layer to form a cylindrical bottom electrode, wherein an inner surface the cylindrical bottom electrode comprises a plurality of protruding portions, and an outer surface of the cylindrical bottom electrode comprises a plurality of concaved portions;
• stripping off the oxide layers and removing the plurality of island structures not covered by the supporting structure, wherein the step of stripping off the oxide layers and removing the plurality of island structures comprises performing a single etching process to remove the oxide layers along with the plurality of island structures;
• conformally forming a dielectric layer on the inner surface and the outer surface of the cylindrical bottom electrode, and covering the plurality of protruding portions and the plurality of concaved portions of the cylindrical bottom electrode;
• and
• conformally forming a top electrode on the dielectric layer over the inner surface and the outer surface of the cylindrical bottom electrode.