Patent attributes
A submicron CMOS transistor is mounted on the same substrate together with an analog CMOS transistor, a high voltage-resistance MOS transistor, a bipolar transistor, a diode, or a diffusion resistor, without degrading the characteristics of these components. When a punch-through stopper area is formed on a main surface side of a semiconductor substrate, an area in which an analog CMOS transistor, a high voltage-resistance MOS transistor, a bipolar transistor, a diode, or a diffusion resistor is formed is masked, and for example, an ion injection is then carried out. Thus, a punch-through stopper area is formed in the area in which a submicron CMOS transistor is formed, while preventing the formation of a punch-through stopper area in the area in which an analog CMOS transistor, a high voltage-resistance MOS transistor, a bipolar transistor, a diode, or a diffusion resistor is formed.