Device simulations of isolation techniques for silicon microstrip detectors made on p-type substrates

Recent studies have shown that silicon particle detectors made on p-type substrates feature an improved radiation hardness compared to more conventional single-side n-type devices. In particular, they show an increased charge collection efficiency at very high irradiation levels. At present few devices have been fabricated on these substrates and there are still many doubts regarding the best type of isolation structure to be employed for the interruption of the inversion electron layer present between the n⁺ electrodes. In this paper, a description of the behavior of microstrip detectors featuring three isolation solution (p-spray, p-stop and a combination between the previous two) is presented. The analysis is based on device simulations and covers the breakdown and interstrip capacitance issues.