Silicon single-electron CCD

Single-electron (SE) devices have been attracting much attention because of their low power consumption and potential for novel functions based on the manipulation of a single charge. Silicon-on-insulator (SOI) wafers are the most feasible material for fabricating SE devices since Si nanostructures can be implemented by the nanolithography technique. We have already reported SE transistors, SE memories and coupled-island SE devices, which were fabricated by means of pattern-dependent oxidation (PADOX). Nevertheless, the ultimate operation, the manipulation of a single charge, such as in a SE pump, has not yet been realized in Si devices and remains a future subject. Here, we report a novel type of SE device, an ultrasmall charge-coupled device (CCD) on a SOI wafer. The fabricated prototype can transfer a single hole like a conventional CCD. We also demonstrate a new method of storing holes and sensing them on the level of a single charge.