Pixel frontend electronics in a radiation hard technology for hybrid and monolithic applications

Pixel detector readout cells have been designed in the radiation hard DMILL technology and their characteristics evaluated before and after irradiation to 14 Mrad. The test chip consists of two blocks of six readout cells each. Two different charge amplifiers are implemented, one of them using a capacitive feedback loop, the other the fast signal charge transfer to a high impedance integrating node. The measurements give the following results: the equivalent noise charge is 110e/sup -/ RMS (150e/sup -/ RMS after irradiation); at a threshold of 5000e/sup -/ (4000e(/sup -/)) the threshold variation is 300e/sup -/ RMS (250e/sup -/ RMS) and the time walk is 40 ns (40 ns). The use of this SOI technology for monolithic integration of electronics and detector in one substrate is under investigation.