Hard mask structure for deep trenched super-junction device

A hard mask structure is disclosed. The hard mask structure is used for manufacturing a deep trench of a super-junction device having a substrate and an epitaxial layer formed on the substrate. The hard mask structure comprises an ion barrier layer formed on the epitaxial layer for blocking ions from diffusing into the epitaxial layer, and a deposition layer formed on the ion barrier layer. Thereby, the deep trench of the super-junction device is formed by performing an etch process on the epitaxial layer via the hard mask structure. The hard mask structure can effectively prevent ions from diffusing into the epitaxial layer, so as to avoid unusual electrical property.