Method for fabricating semiconductor device

A method for fabricating a semiconductor device, comprising:

• forming a plurality of isolation structures in a substrate, wherein the isolation structures extend along a first direction and are arranged in parallel;
• forming a well of a first conductive type in the substrate;
• forming a plurality of first doped regions of a second conductive type in the well, wherein each of the first doped regions is formed between two adjacent isolation structures respectively;
• forming a plurality of gates of the second conductive type on the substrate, wherein the gates extend along a second direction different from the first direction and are arranged in parallel, and one of the first doped regions is electrically connected to one of the gates;
• and
• forming a plurality of second doped regions of the first conductive type in the well, wherein each of the second doped regions is formed in the first doped regions between two adjacent gates respectively.