Improved Performance of Silicon Carbide Detector Using Double Layer Anti Reflection (AR) Coating
Final rept. 10 Oct 2012-1 Jul 2013
ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
Pagination or Media Count:
Avalanche photodiodes fabricated on a silicon carbide SiC substrate showed peak responsivity near 280 nm. The SiC detector structure is grown epitaxially on a 2- m-thick n-type bottom contact layer followed by a 0.48- m lightly doped multiplication layer and a top heavily doped 0.45- m p-type contact layer. Double-layer anti-reflection AR coating is grown by a plasma enhanced chemical vapor deposition PECVD technique at 250 C. Using a double-layer AR coating with a bottom silicon nitride Si3N4 layer and a top silicon dioxide SiO2 layer broadly enhanced responsivity in the full detector spectral range. We observed that the enhancement of the detector responsivity by using double-layer AR coating is higher than the enhancement observed in a similar device with a single-layer AR coating with a SiO2 film. We observed about 28 increases in detector responsivity by using a double-layer AR coating.
- Ceramics, Refractories and Glass
- Coatings, Colorants and Finishes