Stacked focal plane array circuit and method thereof

Abstract

A stacked focal planar array (FPA) device and method of fabrication. The method can include forming photodetectors or FPAs by heteroepitaxial growth of III-V PINs, APDs, or other photodetector devices that are bonded to a Si-based read-out integrated circuit (ROIC) wafer in a stacked configuration. In a single-color device example, a wavelength configuring buffer layer and photodetector are grown on a first substrate using compound semiconductor materials to enable infrared detection at desired wavelength(s). Depending on the application, this growth can be done on a graded compliant buffer layer and/or a selectively transparent buffer layer. And, silicon detectors can be incorporated to detect visible and NIR wavelengths in a dual-color device example. Further, the resulting devices can be bonded overlying the ROIC device in a flipped orientation and configured as pixels in a sensor array device coupled to the ROIC device.