| 摘要 |
A method of making a signal charge transfer device, including the steps of: forming first conductivity-type channel regions (30) in each of second conductivity-type wells (20) formed in a first conductivity-type semiconductor substrate (10); forming a plurality of first electrodes (50a) uniformly spaced from one another, and then forming an insulation film (40) for insulating the first electrodes from one another; forming a primary potential barrier (70) in each of the channel regions by subjecting the channel regions to a primary-ion implantation process using the plurality of first electrodes as a mask; forming a secondary potential barrier (70a) in each of the channel regions at lower corners of each of the first electrodes by subjecting the channel regions to a sloped secondary-ion implantation process using the plurality of first electrodes as a mask; and forming second electrodes (80a), each being disposed between the adjacent ones of the first electrodes, and then forming an insulation film (60) to insulate the second electrodes from one another. According to one embodiment, the sloped secondary implantation includes repeated implantations of B+ ions only into one side of both sides of each of the plurality of first electrodes at 30 DEG -60 DEG to a horizontal line of the semiconductor substrate. According to another embodiment, the sloped ion implantation includes repeated implantations of As or P ions only into one side of both sides of each of the plurality of first electrodes at 120 DEG -150 DEG to the horizontal substrate line.
|
