METHOD FOR IMPROVING DESIGN RULE OF SEMICONDUCTOR DEVICE TO IMPROVE DESIGN RULE MARGIN OF WELL OF SECOND CONDUCTIVITY TYPE

摘要

PURPOSE: A method for improving the design rule of a semiconductor device is provided to improve a design rule margin of a well of the second conductivity type by forming a deeper trench in the well of the second conductivity type than in a well of the first conductivity type. CONSTITUTION: The first insulation layer is formed on a substrate(100). A well(102) of the first conductivity type is formed in a predetermined region of the substrate. Source ions including fluorine are implanted into a region adjacent to the well of the first conductivity type to form a well(103) of the second conductivity type. The substrate in the well of the second conductivity type is more deeply etched than the substrate in the well of the first conductivity type so as to form a step of a trench in the isolation region between the wells of the first and second conductivity types.