Junction and interdiode capacitance of silicon pixel arrays

Several measurements of junction (Cj) and interdiode (Cip) capacitance of silicon pixel detectors have been performed. These quantities play an important role in determining the noise and cross-talk characteristics of the detectors. Moreover, the importance of these measurements is related to the possibility of position interpolation by capacitive charge division and analogue readout in future pixel detectors for precision charged particle tracking in several apparatus connected to different front-end electronics. An attempt to model the interdiode capacitance on the geometry has been made. Good agreement has been found between this simple model and the experimental results. According to the model, by choosing sufficiently close diodes, the CipCj ratio can be made large enough to make capacitive coupling effective.