This invention discloses a semiconductor power device disposed on a semiconductor substrate of a first conductivity type. The semiconductor substrate supports an epitaxial layer of a second conductivity type thereon wherein the semiconductor power device is supported on a super-junction structure. The super-junction structure comprises a plurality of trenches opened from a top surface in the epitaxial layer; wherein each of the trenches having trench sidewalls covered with a first epitaxial layer of the first conductivity type to counter charge the epitaxial layer of the second conductivity type. A second epitaxial layer may be grown over the first epitaixial layer. Each of the trenches is filled with a non-doped dielectric material in a remaining trench gap space. Each of the trench sidewalls is opened with a tilted angle to form converging U-shaped trenches.