Method for manufacturing semiconductor device including a MOS-type transistor

摘要

There is provided a semiconductor device and a method for manufacturing a semiconductor device. Within the N-type semiconductor layer formed from a high resistance N-type substrate, the P-type well diffusion layer and P-type extraction layer are formed and are fixed to ground potential. Due thereto, a depletion layer spreading on the P-type well diffusion layer side does not reach the interlayer boundary between the P-type well diffusion layer and the buried oxide film. Hence, the potential around the surface of the P-type well diffusion layer is kept at a ground potential. Accordingly, when the voltages are applied to the backside of the N-type semiconductor layer and a cathode electrode, a channel region at the MOS-type semiconductor formed as a P-type semiconductor layer is not activated. Due thereto, leakage current that may occur independently of a control due to the gate electrode of a transistor can be suppressed.

主权项

1. A method for manufacturing a semiconductor device comprising:
laminating an oxide film layer and a semiconductor layer of a first-conductive-type on a semiconductor layer of a second-conductive-type in order; forming an active region of the first-conductive-type in the semiconductor layer of the first-conductive-type; forming an insulating film on the semiconductor layer of the first-conductive-type; forming a first region of the first-conductive-type by diffusing, based on a position of the active region of the first-conductive-type, an impurity of the first-conductive-type within a first region of the semiconductor layer of the second-conductive-type that includes a lower portion of the active region of the first-conductive-type; forming a MOS-type transistor in the active region of the first-conductive-type; removing the oxide film layer from a predetermined region, the predetermined region being a region of the semiconductor layer of the first-conductive-type in which a first electrode, a second electrode and a third electrode are to be formed; forming, in the first region of the first-conductive-type, a second region of the first-conductive-type by diffusing the impurity of the first-conductive-type within the predetermined region from which the oxide film layer has been removed and on which the first electrode is to be formed and, forming a third region of the first-conductive-type by diffusing the impurity of the first-conductive-type within the predetermined region on which the third electrode is to be formed; forming a region of the second-conductive-type by diffusing an impurity of the second-conductive-type within the predetermined region from which the oxide film layer has been removed and in which the second electrode is to be formed; and forming the first electrode, the second electrode and the third electrode.