Recent development of detectors with integrated capacitors and polysilicon resistors

A silicon microstrip detector has been developed with capacitive coupling of the diode strips to the metallization and with polysilicon bias resistors to each diode. It allows the decoupling of the leakage current from the input to the charge-sensitive amplifier. Results are given on the coupling capacity and the breakdown voltage as well as on the polysilicon line resistance. It is found that the coupling capacitance, varying between 25 pF and 80 pF as a function of the oxide thickness, is large enough to avoid capacitance signal losses to the backplane. The 200-nm-thick silicon oxide withstands a potential difference of 100 V or more, thus allowing the operation of the detector with the metal strips and backplane at a ground potential and the bias voltage applied to the diodes.<>