Method for forming triple well in semiconductor device

Abstract

An improved method for forming a triple well of a semiconductor device which is capable of more simply and easily forming a triple well without removing an anti-oxidation film. In addition, it is possible to reduce the amount of the removal of the field oxidation film and to improve the characteristics of the latch-up and the device isolation, which includes the steps of preparing a first conductive type semiconductor substrate having an active region and a field region, forming a buffer film on the active region of the substrate and an anti-oxidation film on the buffer film, forming a field oxidation film on the field region, forming a second conductive type first dopant region on the substrate by implantating a first ion through the field oxidation film and the anti-oxidation film, forming a first conductive type first dopant region by implantating a second ion in a first well region of the substrate, forming a first conductive type second dopant region by implantating a third ion in a second well region of the substrate, which the second well region is spaced apart from the first well region, and forming a second conductive type second dopant region by implantating a fourth ion in a third well region of the substrate between the first well region and the second well region.