First tests with fully depleted pn-CCD´s

The authors have fabricated 280- mu m-thick fully depletable p-n charge -coupled devices (CCDs) on high-resistivity silicon ( approximately 2.5 k Omega -cm). Their operation is based on the semiconductor drift-chamber principle. They are designed as energy- and position-sensitive radiation detectors for (minimum) ionizing particles and X-ray imaging. Two-dimensional semiconductor device modeling demonstrates the basic charge-transfer mechanisms. Prototypes of the detectors have been tested in static and dynamic conditions. A preliminary charge-transfer inefficiency was determined 6*10/sup -3/. The charge loss during the transfer is discussed, and an improved design, which is now being produced, is presented.<>