Technology of p-type microstrip detectors with radiation hard p-spray, p-stop and moderated p-spray insulations

Abstract

A technology for the fabrication of p-type microstrip silicon radiation detectors using moderated p-spray implant insulation has been developed at CNM-IMB. The p-spray insulation has been optimized in order to withstand the ionizing irradiation dose expected in the middle region of the SCT-ATLAS detector of the future Super Large Hadron Collider (s-LHC) during 10 years of operation. A dedicated mask was designed in order to fabricate pad diodes with different sizes and test structures to measure the surface resistivity. The best technological options for the moderated p-spray implants were found by using a simulation software package and a dedicated calibration run. Detectors have been fabricated with Float Zone (FZ) p-type high resistivity silicon substrates in the Clean Room facility of CNM-IMB, and characterized by reverse current and capacitance versus voltage measurements. The detectors fabricated with the moderated p-spray technology are compared to similar detectors fabricated with p-stop and p-spray insulation implants. A dedicated test structure was used to measure the interstrip resistance.