Details

Autor(en) / Beteiligte

• Cicek, E.
• McClintock, R.
• Vashaei, Z.
• Zhang, Y.
• Gautier, S.
• Cho, C. Y.
• Razeghi, M.

Titel

Crack-free AlGaN for solar-blind focal plane arrays through reduced area epitaxy

Ist Teil von

• Applied physics letters, 2013-02, Vol.102 (5)

Erscheinungsjahr

2013

Quelle

AIP Journals Complete

Beschreibungen/Notizen

• We report on crack reduction for solar-blind ultraviolet detectors via the use of a reduced area epitaxy (RAE) method to regrow on patterned AlN templates. With the RAE method, a pre-deposited AlN template is patterned into isolated mesas in order to reduce the formation of cracks in the subsequently grown high Al-content AlxGa1−xN structure. By restricting the lateral dimensions of the epitaxial growth area, the biaxial strain is relaxed by the edges of the patterned squares, which resulted in ∼97% of the pixels being crack-free. After successful implementation of RAE method, we studied the optical characteristics, the external quantum efficiency, and responsivity of average pixel-sized detectors of the patterned sample increased from 38% and 86.2 mA/W to 57% and 129.4 mA/W, respectively, as the reverse bias is increased from 0 V to 5 V. Finally, we discussed the possibility of extending this approach for focal plane array, where crack-free large area material is necessary for high quality imaging.