Martha—First measurement results

In order to achieve a pixel diode inherent signal amplification, Low Gain Avalanche Diodes (LGADs) have come into focus of pixel detector developments. However, in contrast to conventional diode arrays, the detector response in the pixel gap areas is still problematic for LGADs. The Monolithic Array of Reach THrough Avalanche photo diodes (MARTHA), is a novel concept for proportional mode Avalanche Photo Diodes (APDs), that provides a 100% fill factor and a high detection efficiency also in the gap regions. An n-doped field drop layer between the n+ pixel structure and an unstructured p-doped multiplication layer suppresses electric field peaks at the pixel edges and leads to a fairly homogeneous amplification over the sensor area. Edge breakdown suppression could already be demonstrated by static measurements on special diodes. In this paper we present further static and first dynamic and position dependent measurements on segmented sensors.