Plasma and process damage can have many different signatures that are observable in multiple ways in the massive amount of data taken during a CMOS manufacturing process. Some signals may be observed in global signals, such as chip yield, burn-in yield, and qualification failure. Parametric data is often the primary means of detecting damage problems. The damage parametric data can take multiple statistical forms, including a shift in the mean value, the development of a defect subpopulation showing as kurtosis, creating a defect tail, or a significant increase in the variation of a parameter. Plasma and process damage can appear in statistical process control data, such as parametric trend charts correlating with tool excursions, preventative maintenance, etc. Damage may be cumulative as a wafer is processed through the CMOS process flow, with multiple steps damaging the chip, each damaging step adding to the degradation of the chip. This chapter covers these topics, showing examples of actual data.