Patent ID: 8772854

Claim:
A device comprising: a first active region comprising a well region of a first conductivity type; a Shallow Trench Isolation (STI) region adjacent to the first active region; and a coupling capacitor comprising: a first floating gate as an upper capacitor plate of the coupling capacitor; a doped semiconductor region as a lower capacitor plate of the coupling capacitor, wherein the doped semiconductor region is of a second conductivity type opposite to the first conductivity type, and wherein the doped semiconductor region comprises: a top portion at a top surface of the first active region, wherein the top portion comprises a bottom surface contacting a top surface of the well region; a bottom portion comprising a top surface contacting a bottom surface of the STI region; and a sidewall portion connecting the top portion to the bottom portion, wherein the sidewall portion is in contact with a sidewall of the well region; and a capacitor insulator between the upper capacitor plate and the lower capacitor plate, wherein the capacitor insulator comprises an upper portion, and a sidewall portion lower than a bottom surface of the upper portion.