Charge transfer pickup unit and its driving method

Abstract

Abstract PURPOSE: To prevent a blooming phenomenon and also to improve a degree of integration by connecting an excessive charge absorbing channel, adjoining to a photoelectric conversion region and divided by a channel stop region, to a gate electrode forming a potential well. CONSTITUTION: To photo gate 15, a direct current is applied to form a potential well of photoelectric conversion regions 18a and 18b. Once control gate electrode 14 becomes high in level, a potential under electrode 14 becomes 17b and charge in photoelectric conversion part 18 is transferred to potential well 17c right under transfer electrode 13a. When electrode 14 becomes low in level, a potential right under electrode 14 becomes 17b'. Irradiation with light via photo gate 15 accumulates signal charge in the potential well encircled with 17b and 17a. Potential barrier region 19 controls the impurity density of the substrate and decreases an electron potential in the well down to a minimum with electrode 15 biased. Therefore, the excessive charge flows into excessive-charge absorbing N + region 16 by way of region 19. In this way, electrode 15 controls the surface potential of region 19 while forming the well, and is connected to region 16 via contact 20, thereby realizing a function of an electrode line through which the excessive charge flows out. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Yasuo Ishihara

Bibliographic Details