METHOD OF REDUCING SURFACE DOPING CONCENTRATION OF DOPED DIFFUSION REGION, METHOD OF MANUFACTURING SUPER JUNCTION USING THE SAME AND METHOD OF MANUFACTURING POWER TRANSISTOR DEVICE

摘要

The present invention provides a method of reducing a surface doping concentration of a doped diffusion region. First, a semiconductor substrate is provided. The semiconductor substrate has the doped diffusion region disposed therein, and the doped diffusion region is in contact with a surface of the semiconductor substrate. A doping concentration of the doped diffusion region close to the surface is larger than a doping concentration of the doped diffusion region away from the surface. Then, a thermal oxidation process is performed to form an oxide layer on the surface of the semiconductor substrate. A part of the doped diffusion region in contact with the surface reacts with oxygen to form a part of the oxide layer. Then, the oxide layer is removed.