AlGaN-on-Si-Based 10- \mu\hbox Pixel-to-Pixel Pitch Hybrid Imagers for the EUV Range

• Published in: IEEE electron device letters Vol. 32; no. 11; pp. 1561 - 1563
• Main Authors: Malinowski, P. E., Duboz, J., De Moor, P., John, J., Minoglou, K., Srivastava, P., Semond, F., Frayssinet, E., Giordanengo, B., BenMoussa, A., Kroth, U., Gottwald, A., Laubis, C., Mertens, R., Van Hoof, C.
• Format: Journal Article
• Language: English
• Published: IEEE 01-11-2011
• Subjects: Aluminum gallium nitride; Aluminum gallium nitride (AlGaN); backside illumination; Detectors; extreme ultraviolet (EUV); flip chip; high resolution; hybrid imager; Protons; Schottky diodes; Silicon; Substrates; ultraviolet imaging; Ultraviolet sources
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2011.2163615

We report on the fabrication of extreme ultraviolet (EUV) hybrid imagers with backside-illuminated detector chip based on aluminum gallium nitride (AlGaN) layers grown on silicon and integrated with CMOS readout chip. The focal plane array (FPA) size is 256 × 256 pixels with 10-μm pixel-to-pixel pitch. The devices were characterized at wavelengths from 300 down to 1 nm using synchrotron radiation. An upper cutoff wavelength of 280 nm was observed, as expected from the AlGaN active layer composition (40% Al). Thus, the imagers have a high rejection ratio of the near UV and visible radiation. Moreover, no degradation due to proton irradiation was observed for 60-MeV energy and 5 ·10 10 protons/cm 2 dose. Furthermore, devices with thin silicon substrate layer that is intentionally left were fabricated, and response only in the EUV range was observed. These results demonstrate the possibility of achieving high-resolution EUV imaging with AlGaN-based FPAs, which is very promising for high-end industrial, scientific, and space applications.