Manufacturing method of semiconductor device

A method of manufacturing a semiconductor device, comprising:

• forming wells in a semiconductor substrate by implanting ions thereinto;
• forming a field oxide layer on the semiconductor substrate;
• forming a gate oxide layer on the semiconductor substrate;
• forming a first conductive layer on the gate oxide layer and the field oxide layer;
• forming a capacitor dielectric layer on the first conductive layer;
• forming a second conductive layer on the capacitor dielectric layer;
• patterning the first and second conductive layers, the gate oxide layer, and the capacitor dielectric layer so as to form a gate pattern and a capacitor pattern;
• selectively wet-etching the first and second conductive layers such that the capacitor dielectric layer becomes outwardly protrudent at a protruding portion thereof;
• implanting ions into the semiconductor substrate using the gate pattern and the protruding portion of the capacitor dielectric layer as an implantation mask;
• removing the protruding portion of the capacitor dielectric layer so that the patterned capacitor dielectric layer has the same width as a gate electrode and a first capacitor electrode, respectively;
• and
• selectively removing the capacitor dielectric layer on the gate electrode and the second conductive layer on the gate electrode.