论文部分内容阅读
业已表明,硅电荷耦合器件中,电荷转移的极限速度受硅中碰撞电离和饱和漂移速度的限制。当 L≤10μm 时,埋沟器件(BCCD)的电荷转移速度随着两个相邻栅间的中心距离 L 而线性地下降。只有当 L≤2μm 时表面沟道器件(SCCD)转移速度的下降才是成线性的,但对 L>2μm 时,下降的非常快。当 L≤2μm时 SCCD 和 BCCD 两者的极限电荷转移时间大致相同,相应的时钟频率在千兆赫范围内。也讨论了用窄禁带化合物半导体制作的电荷耦合器件。尽管有较高的载流子迁移率,但由于在高电场下带间碰撞产生电子-空穴对,用这些材料制作的器件也不能在超过千赫～兆赫范围的时钟频率下工作。
It has been shown that in silicon charge-coupled devices, the ultimate rate of charge transfer is limited by the impact ionization and saturation drift speeds in silicon. When L ≦ 10 μm, the charge transfer rate of the buried channel device (BCCD) decreases linearly with the center distance L between two adjacent gates. The drop in surface channel device (SCCD) transfer speed is linear only for L ≤ 2 μm, but very fast for L> 2 μm. The limit charge transfer time for both SCCD and BCCD is approximately the same for L <2 [mu] m with the corresponding clock frequency in the gigahertz range. Charge-coupled devices made with narrow bandgap semiconductors are also discussed. Despite the higher carrier mobility, devices fabricated with these materials can not operate at clock frequencies in the kilohertz-to-megahertz range due to electron-hole pairs created by inter-band collisions at high electric fields.