Proton radiation testing of Leonardo large format MCT arrays

Lead Organisation: Leonardo MW Ltd.
Project Lead: Mark Herrington

In response to the CEOI 10th Call for Earth Observation Technology and Instrument Development Proposals Leonardo are submitting a fast track programme of work under the theme of ‘New and innovative ideas for EO technology projects’.

The proposed work is aimed at raising the Technology Readiness Level (TRL) of the NIR and SWIR large format arrays developed for ESA, using a radiation hard cell library in 0.35 micron CMOS silicon and enabled for avalanche photodiode operation. This will provide valuable evidence for de-risking the use of these devices and others yet to be developed in the same CMOS technology, for future earth observation missions such as those proposed for ESA Earth Explorer 9 and 10. It would therefore provide a return on the investment made in the ESA Earth Observation programme by the UK, through exploitation of leading edge infrared detector technological capability.

Previous work carried out successfully with NSTP and CEOI funding has demonstrated the performance of MCT avalanche photodiode arrays under a range of operating conditions and characterized the immunity to heavy ion radiation of arrays using the near infrared large format silicon readout IC. This project has undertaken proton testing on the NIR large format arrays which has provided valuable information on their operability under radiation and specifically the nature of the effects to determine whether they are permanent or can be managed through appropriate operating procedures controlled from the host system.

The silicon readout ICs (ROICs) are enabled for use with MCT diode arrays operating at unity gain as conventional diodes and in avalanche gain mode by adjustment of the operating voltage. When this virtually noiseless gain is combined with low noise ROIC technology and MCT diode array formats up to 2000 by 2000 pixels, it offers a disruptive technology to provide improvements in the quality of data available to scientists without compromising the payload size, weight or power. This combination of features has already been exploited in other high performance applications such as wavefront sensors for ground based astronomy and will be brought closer to deployment for space applications through the work proposed.

The result of successful completion of this work would be high performance large format MCT array designs which could be rapidly deployed for space applications using existing space qualified manufacturing techniques most recently exploited during the detector development for the IASI NG programme.