Abstract: Provided is a power semiconductor device and a fabrication method thereof are provided. The power semiconductor device includes: a first epitaxial layer; a collector layer formed on one side of the first epitaxial layer; and a second epitaxial layer formed on another side of the first epitaxial layer, the first epitaxial layer having a higher doping concentration than the second epitaxial layer.

Abstract: A power semiconductor device includes a semiconductor substrate, trench structures comprising a first, a second, a third and a fourth trench structure formed in the substrate, a second conductivity type body region formed between the trench structures, a first conductivity type source region formed in the second conductivity type body region, and an emitter electrode and a gate pad formed over the substrate, wherein each trench structure includes a top electrode and a bottom electrode, and each top electrode is insulated from the corresponding bottom electrode, and wherein the first trench structure is symmetric to the fourth trench structure, and the second trench structure is symmetric to the third trench structure, and wherein the first trench structure is not identical to the second trench structure, and wherein no first conductivity type source region is formed to be adjacent to the second trench structure and the third trench structure.

Abstract: A power semiconductor device includes a semiconductor substrate, trench structures comprising a first, a second, a third and a fourth trench structure formed in the substrate, a second conductivity type body region formed between the trench structures, a first conductivity type source region formed in the second conductivity type body region, and an emitter electrode and a gate pad formed over the substrate, wherein each trench structure includes a top electrode and a bottom electrode, and each top electrode is insulated from the corresponding bottom electrode, and wherein the first trench structure is symmetric to the fourth trench structure, and the second trench structure is symmetric to the third trench structure, and wherein the first trench structure is not identical to the second trench structure, and wherein no first conductivity type source region is formed to be adjacent to the second trench structure and the third trench structure.

Abstract: Provided is a power semiconductor device and a fabrication method thereof are provided. The power semiconductor device includes: a first epitaxial layer; a collector layer formed on one side of the first epitaxial layer; and a second epitaxial layer formed on another side of the first epitaxial layer, the first epitaxial layer having a higher doping concentration than the second epitaxial layer.

Abstract: Provided is a power semiconductor device and a fabrication method thereof are provided. The power semiconductor device includes: a first epitaxial layer; a collector layer formed on one side of the first epitaxial layer; and a second epitaxial layer formed on another side of the first epitaxial layer, the first epitaxial layer having a higher doping concentration than the second epitaxial layer.

Abstract: Provided is a power semiconductor device and a fabrication method thereof are provided. The power semiconductor device includes: a first epitaxial layer; a collector layer formed on one side of the first epitaxial layer; and a second epitaxial layer formed on another side of the first epitaxial layer, the first epitaxial layer having a higher doping concentration than the second epitaxial layer.

Abstract: Disclosed herein is a method for preparing oxytitanium phthalocyanine as a charge generating material. The method comprises the steps of mixing 30˜100 wt % sulfuric acid and an oxytitanium phthalocyanine crude in a mixing ratio between 100:1 and 1:1, homogeneously grinding the mixture in a wet grinder filled with zirconia or glass beads as grinding media at ?20° C.˜60° C. for 0.1˜24 hours, and removing the grinding media from the ground mixture using a solvent. According to the method, oxytitanium phthalocyanine usable as a high-quality charge generating material can be prepared without the use of expensive and difficult-to-handle reactants, such as trifluoroacetic acid and pentafluoropropionic acid. Further disclosed is an oxytitanium phthalocyanine charge generating material prepared by the method.