Method for manufacturing semiconductor device by performing multiple ion implantation processes

A method for manufacturing a semiconductor device comprising the steps of:

• performing a first ion implanting process for implanting an n-type impurity with a first dose on a surface of a semiconductor wafer to form an n-type impurity layer on the surface of the semiconductor wafer;
• coating resist on the surface of the side where the n-type impurity layer is formed in the semiconductor wafer;
• exposing the semiconductor wafer selectively to pattern the resist;
• and
• performing a second ion implanting process for implanting a p-type impurity with a second dose greater than the first dose using the remaining part of the resist as a mask to form a p-type impurity layer in the interior of the n-type impurity layer
• wherein Rp1, ΔRp1, Rp2, and ΔRp2 are defined as the projected range of the n-type impurity in the first ion implanting process, the standard deviation of the projected range Rp1, the projected range of the p-type impurity in the second ion implanting process, and the standard deviation of the projected range Rp2, respectively, and wherein the following equation 1 is satisfied as:
• Rp2+3·ΔRp2≧Rp1+3ΔRp1 (1).