| 摘要 |
PURPOSE:To prevent the lowering of the transfer efficiency of charges and the generation of noises by making the electrode length of one electrodes of a large number of electrode pairs smaller than that of the other electrodes while forming impurity regions having the same conduction type as a semiconductor substrate and high concentration to the deep sections of the semiconductor substrate under one electrode. CONSTITUTION:The electrode length of first electrodes 31 is set to size shorter than the electrode length of second electrodes 32, and the whole device is fined and P<+> type buried impurity regions 4 into which an impurity having the same conduction type as a P type semiconductor substrate 1 is introduced in high concentration are shaped to the deep sections of the semiconductor substrates 1 under each first electrode 31.... The positions of existence in the depth direction in the semiconductor substrate 1 of the regions 4... are kept within a range among the positions of the lower limits of depletion layers (d) formed under the second electrodes 32 under an OFF state and the positions of the lower limits of depletion layers (b) shaped under the second electrodes 32 under an ON state as shown in a broken line, and it is desirable that the positions of the upper end surfaces of the regions 4 are conformed approximately to the positions of the lower limits of depletion layers (c) formed under the first electrodes 31 under the ON state and the positions of the lower end surfaces of the regions 4 are conformed approximately to the positions of the lower limits of the depletion layers (b). |
