This chapter provides background and history of plasma and process damage, along with a high-level survey of the types of defects encountered in the manufacture of CMOS chips. Numerous electrical and physical defects can be caused by plasma and process damage. A high-level survey of the commonly known defects are described. Multiple types of structures and devices can be damaged by process damage, including CMOS transistors, diodes, metal-insulator-metal (MIM) capacitors, shallow trench isolation (STI), low-k dielectrics, parametric test structures, nonvolatile memories, DRAM, memory wordlines, CMOS imagers, silicon on insulator (SOI), finfets, contacts and vias, and metallization. The details of plasma and process damage are described for each type of structure, device, and technology.