| 摘要 |
PURPOSE:To obtain a charge coupled device which has a remarkably thick depletion layer as compared with a conventional one by connecting DC bias means for applying a DC bias voltage of the polarity to become recverse bias to a semiconductor substrate in series with a clock pulse voltage source. CONSTITUTION:Electrodes 3 are sequentially connected to three clock pulse voltage sources 4 for transferring signal charges sequentially having phases phi1, phi2, phi3. A voltage source 5 grounded at one terminal and connected at the other terminal to one terminal of the source 4 for applying a DC bias voltage in series with the source 4 is decided in the polarity so that a semiconductor substrate 1 is reversely biased in such a manner to be positive when the substrate 1 is P type and negative when the substrate 1 is N type. When the voltage value of the source 5 is set to a value larger than the voltage value of the source 4 within a range which does not cause an insulation damage in the semiconductor, the thickness of the depletion layer in the semiconductor disposed directly under the electrodes 3 can be almost set to the large value determined by the voltage value of the source 5. |
