| 摘要 |
PURPOSE: A method for manufacturing semiconductor power switching devices is provided to improve switching speed by selectively diffusing dopants into an epitaxial layer in order to control lifetime of excess minor carrier. CONSTITUTION: The first heavily doped epitaxial layer(10a) and the second lightly doped epitaxial layer(10b) having large resistivity are sequentially formed. After forming a base and an emitter in the second lightly doped epitaxial layer(10b), an insulation layer(40) is formed on the surface of the resultant structure. After forming a base contact(20b) and an emitter contact(30b), a base electrode(20c) and an emitter electrode(30c) are filled into the base and emitter contacts(20b,30b), respectively. By etching the first heavily doped epitaxial layer(10a), a plurality of windows are spaced apart from each other, so that the second lightly doped epitaxial layer(10b) is partially exposed. After selectively diffusing dopants into the second lightly doped epitaxial layer(10b), a collect electrode(10c) is formed to simultaneously contact the first heavily doped epitaxial layers(10a) and the second lightly doped epitaxial layer(10b).
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