| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a reverse blocking insulating gate bipolar transistor, with which the occupation area ratio of a separation region per chip can be made small and diffusion time can be shortened, even in the case of a thin wafer (semiconductor substrate) where tradeoff of an on-voltage characteristic and turn-off loss can be avoided. SOLUTION: An oxide film and resist are formed on a first conductive substrate becoming a drift layer. A trench is formed in an opening. A second conductive epitaxial layer is formed in the trench. The surface structure is formed in a base region, a gate oxide film, a gate electrode, an emitter region, and an emitter electrode. The second conductive epitaxial layer formed in the trench is annealed in heat treatment at the time of forming the surface structure. A separation layer is formed by annealing. The rear face of the substrate is ground until it reaches the separation layer. A collector layer is formed by ion implantation and annealing of second conductive impurity. Thus, the separation layer is formed by high temperature heat treatment in short time. Consequently, an oxygen take-in amount is reduced and spreading of the separation layer is suppressed in a lateral direction. COPYRIGHT: (C)2006,JPO&NCIPI
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