Patent ID: 7863147

Claim:
A method for fabricating a semiconductor device, comprising: providing a semiconductor substrate; forming a first type well in the semiconductor substrate; and forming a second type well and a plurality of junction regions in the semiconductor substrate, wherein each of the junction regions is between the first and the second type wells, and adjoins the first and the second type wells, and wherein the step of forming the first type well, the second type well and the plurality of junction regions, comprises: forming a first photoresist layer on the semiconductor substrate; providing a first mask; using the first mask to perform an exposure to transfer a pattern on the first mask onto the first photoresist layer on the semiconductor substrate; using the first photoresist layer as a mask to perform a first type ion implant to form the first type well in the semiconductor substrate; removing the first photoresist layer; forming a second photoresist layer on the semiconductor substrate; providing a second mask; using the second mask to perform an exposure to transfer a pattern on the second mask onto the second photoresist layer on the semiconductor substrate; and using the second photoresist layer as a mask to perform a second type ion implant to form the second type well and the plurality of junction regions in the semiconductor substrate, wherein each of the junction region is between the first and the second type wells, and adjoins the first and the second type wells.