A New Generation of MCT-Based p-on-n Technology for Focal-Plane Arrays Ranging from SWIR to VLWIR

Abstract The recent advancements in antimonide-based technologies for cooled infrared imaging systems, coupled with the industry trend toward SWaP-C (size, weight, and power-cost), have led to a heightened emphasis on the manufacturing efficiency and performance stability of infrared focal-plane arrays (IRFPAs). This article presents a new generation of p-on-n technology for IRFPAs based on mercury cadmium telluride (MCT), developed by the joint laboratory of Leti and Lynred. This development is specifically designed to address the growing need to enhance the electro-optical performance of the devices, particularly in terms of image quality and low-frequency stability. The new process outlined herein is founded upon three key features: the utilization of high-quality materials, the optimization of the process through the application of fundamental research, and the implementation of a dedicated diode architecture. The versatility of MCT enables this technology to cover a broad spectral range, from short-wave infrared (SWIR) to very long-wave infrared (VLWIR). This paper presents the successful fabrication of IRFPAs that span this entire spectral range and the results of an electro-optical characterization of the aforementioned prototypes, with a particular focus on low-frequency performance metrics. The results demonstrate that this new generation of p-on-n devices exhibits enhanced operability and uniformity across the focal-plane array, which is characteristic of this new p-on-n generation. These improvements result in notable enhancements in residual fixed-pattern noise (RFPN) for high-temperature applications in the mid-wave band and reduced persistence for astronomical applications.