Diffractive microlens array monolithic integration with PtSi focal plane array

A diffractive microlens arrays can completely collect the light at the focal plane and concentrate it into a smaller spot size on the detector plane; the photodetector area can be substantially reduced. Increased gamma radiation hardening and noise reduction result from the decrease in photodectector sensitive area. The diffractive microlens arrays have been designed by considering the independent optical and processing parameters for PtSi focal plane array. They have been fabricated on the backside of PtSi focal plane array chip by successive photolithography and Ar/sup +/ ion-beam-etching technique. The alignment of microlens arrays with PtSi focal plane array was completed by a backside aligner with IR light source. The practical processes and fabrication method are discussed. The performance parameters of PtSi FPA with diffractive microlens array are presented.