Patent ID: 8268693

Claim:
A method of forming an integrated circuit, the method comprising: locally oxidizing exposed surfaces of a substrate to form an oxide layer extending into the substrate with exposed active regions of the substrate, the exposed active regions including at least one active region of a first electrical conductivity type surrounded by the oxide layer; forming a gate over the at least one active region, the gate having a first portion connected to a second portion, the second portion surrounding the at least one active region and extending from atop the oxide layer inwardly onto the at least one active region, the first portion extending across the at least one active region to define an exposed drain region of the at least one active region between one side of the first portion and the second portion and an exposed source region of the at least one active region between an opposite side of the first portion and the second portion, the at least one active region defining a channel having a length between the exposed drain region and the exposed source region, the second portion of the gate formed to define a distance between an edge of the exposed drain region defined by the second portion and an adjacent edge of the oxide layer that is greater than half the channel length; introducing impurities of a second electrical conductivity type into the exposed source and drain regions; and forming a guardring region of the first electrical conductivity type in another of the exposed active regions of the substrate surrounding the source region, the drain region and the gate.