InGaAs infrared detector development for SWIR imaging applications

Abstract

We report on materials and technology development for short-wave infrared photodetectors based on InGaAs p-i-n and avalanche photodiodes (APDs). Using molecular beam epitaxy for the growth of thin layers with abrupt interfaces, which are required for optimized APD structures, excellent crystalline quality has been achieved for detector structures grown on 3-inch InP substrates. For the fabrication of focal plane detector arrays, we employed a mesa etching technology in order to compare the results with the commonly utilized planar technology. Camera detector arrays as well as test structures with various sizes and geometries for materials and process characterization are processed using a dry-etch mesa technology. Aspects of the process development are presented along with measured dark-current and photo-current characteristics of the detector devices.