| 摘要 |
PURPOSE:To obtain the maximum amount of accumulation and transfer by a method wherein a barrier and an accumulation part are so constructed that the maximum channel potential of the barrier at the high level of a transfer CP of a two-phase CCD becomes in the state immediately before thermal contact with accumulation charges and the interface between a semiconductor and an insulator. CONSTITUTION:In the two-phase CCD wherein gate electrodes 10 and 11 are provided on a p type Si substrate 7 via an n channel 8 and an SiO2 9, the channel potential is given to a gate voltage VG by means of curves I and II from a fixed parameter. The charge is kept accumulated from the point of intersection A' of the curves I and II for the high voltage VGh of the accumulation part up to the potential of the points B' and C'. At this time, the points of intersection B' and C' are positioned deeper than the point of intersection D' (the maximum channel potential of the barrier) of the curve I ' for the barrier of VGh and the curve II by a thermal contact potential DELTAV. When the position of the point C' is at a position determined by the fixed relation between DELTAV or Si dielectric constant and channel concentration, the maximum amount of charges can be accumulated. Besides, ND<-> and a diffusion length Xn are so determined that the curve I ' reaches the point D' from the position of VG-VFB. The sign VFB represents a flat band voltage. |
