Haze formation on reticle continues to be a significant source of concern for the photolithography. Possible sources and causes continue to be investigated. This paper provides a haze source evaluation result under the sub-pellicle defect on the mask. It is well known that there are several sources to produce the haze. One is inorganic molecules such as SOx, NH3, H2O and CO2. The haze formation of inorganic sources is promoted for growing defect size by the exposure energy in time. The other is organics that are prevalent Fab and storage environment. In this paper, we deal with the haze that is immediately generating with a low energy exposure. Especially, this study treats the haze source during the mask packaging method.