Method for manufacturing a semiconductor device

A method of manufacturing a semiconductor device comprising:

• forming a first semiconductor region of a first conductive type and a second semiconductor region of a second conductive type in a predetermined region of a semiconductor substrate of the first conductive type;
• controlling threshold voltages corresponding to each transistor formed on the semiconductor substrate, the first semiconductor region and the second semiconductor region respectively by first to third ion implantation processes executed sequentially,
• wherein the first ion implantation process is executed in a high-threshold low-voltage transistor forming region of the first semiconductor region after the forming the first semiconductor region;
• the second ion implantation process is executed simultaneously in a low-threshold low-voltage transistor forming region of the semiconductor substrate and the high-threshold low-voltage transistor forming region of the second semiconductor region;
• and the third ion implantation process is executed in the low-threshold low-voltage transistor forming region of the second semiconductor region.

A method of manufacturing a semiconductor device comprising:

• forming a first semiconductor region of a first conductive type and a second semiconductor region of a second conductive type in a predetermined region of a semiconductor substrate of the first conductive type;
• controlling threshold voltages corresponding to each transistor formed on the semiconductor substrate, the first semiconductor region and the second semiconductor region respectively by first to fourth ion implantation processes executed sequentially;
• wherein the first ion implantation process is executed in a high-threshold low-voltage transistor forming region of the first semiconductor region after the forming the first semiconductor region;
• the second ion implantation process is executed in a high-threshold low-voltage transistor forming region of the second semiconductor region;
• the third ion implantation process is executed in the low-threshold low-voltage transistor forming region of the second semiconductor region;
• and the fourth ion implantation is executed simultaneously on the low-threshold low-voltage transistor forming region and the high-voltage transistor forming region of the semiconductor substrate respectively.