Development of flip-chip bonding technology for (Cd,Zn)Te

A flip-chip bonding technology has been developed for CdTe and (Cd,Zn)Te X-ray detectors. The aim of this paper is to choose a suitable chip interconnection technique for the fabrication of X-ray pixel detectors to fit the material requirements of detector grade CdTe and (Cd,Zn)Te. The proposed method is based on a flexible process, which permits the use of an eutectic PbSn alloy with a photoresist mask. A photosensitive polymer acts as a passivation layer and solder stop mask on CdTe or (Cd,Zn)Te. The proposed process provides the opportunity to do all process steps "in-house.".