| 摘要 |
PROBLEM TO BE SOLVED: To provide a CCD image sensor capable of improving efficiency of transfer of charges by reducing generation of crystal defect. SOLUTION: In the CCD image sensor in which a large number of electrodes 30, 40 for charge transfer are disposed in an n well via an insulating film 20, the electrode 30 has a structure in which a p-type polysilicon 31 and an n-type polysilicon 32 are sequentially disposed toward a charge transfer direction, and the electrode 40 has a structure in which a p-type polysilicon 41 and an n-type polysilicon 42 are sequentially disposed toward a charge transfer direction. In such a configuration, a potential gradient due to a difference in work function between the p- and n-type polysilicons can be generated on an n-well 12 immediately below the electrodes 30, 40 without implanting ions onto the surface of a semiconductor substrate and the potential gradient matches the charge transfer direction, the charge transfer efficiency can be improved. COPYRIGHT: (C)2008,JPO&INPIT
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