In order to change the electrical property of the semiconductor, the semiconductor manufacturing process will add other atoms in the silicon wafer (such as boron, phosphorus, nitrogen…etc.). In a process is called doping. There are some common doping techniques such as high-temperature diffusion doping, high energy ion beam implantation, and plasma doping … and so on. This research focuses on the topic of over doping of nitrogen ions in the plasma doping process. The over doping of nitrogen easily causes a reaction between the nitrogen ion and photoresist. That leads to the photoresist not successfully stripped on cleaning procedure, which affects the production rate. In our study, we use Function Analysis, Cause-Effect Contradiction Chain Analysis, Contradiction Matrix & 40 Invention Principles and other analytical tools to solve the engineering contradictions and the physical contradictions of nitrogen doping process based on the Systematic innovation procedure.