CMOS WELL STRUCTURE AND FORMING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a CMOS well structure and a method for forming it. SOLUTION: A method for forming a CMOS well structure comprises a process of forming multiple first conductivity type wells over a substrate. The multiple first conductivity type wells are formed in respective openings in a first mask. A cap is formed over each of the first conductivity type wells, and the first mask is removed. Sidewall spacers are formed on the sidewalls of each of the first conductivity type wells. Multiple second conductivity type wells are formed in respective areas between the first conductivity type wells. Multiple shallow trench isolations are formed between the first conductivity type wells and the second conductivity type wells. The multiple first conductivity type wells are formed in a first selective epitaxial growth process, and the multiple second conductivity type wells are formed in a second selective epitaxial growth process. COPYRIGHT: (C)2005,JPO&NCIPI