Hard mask structure for deep trench super-junction device

A hard mask structure for use in manufacturing deep trench of a super-junction device is disclosed, where the super-junction device includes a substrate and an epitaxial layer formed on the substrate. The hard mask structure includes an ion barrier layer formed on the epitaxial layer for separating the ions from diffusing into the epitaxial layer, and a deposition layer formed on the ion barrier layer and cooperating with the ion barrier layer to form the hard mask structure so that the deep trench of the super-junction device can be formed by performing en etch process on the epitaxial layer via the hard mask structure. The hard mask structure can prevent the ions from diffusing into the epitaxial layer and prevent the electrical property of the device for being unusual.