| Title |
[REGULAR PAPER] Selective Annealing Effects in Asymmetric Metal-semiconductor-metal AlGaN UV Sensors |
| Authors |
(Byeong-Jun Park) ; (Jeong-Hoon Seol) ; (Sung-Ho Hahm) |
| DOI |
https://doi.org/10.5573/JSTS.2020.20.6.510 |
| Keywords |
AlGaN sensors; UV-to-visible rejection ratio; ultraviolet; local breakdown; Al composition |
| Abstract |
Asymmetric metal-semiconductor-metal (MSM) AlGaN ultraviolet (UV) sensors with 33 % and 39 % Al composition were fabricated using the selective annealing method. Diodes with lower Al compositions exhibited lower dark current densities and improved UV sensing properties. TEM-EDS analysis showed that the selective annealing caused interdiffusion between the metals; the interface was modified by N penetration into the Ti layer. For UV sensors with Al composition of 33 %, the dark current density and the UV-to-visible rejection ratio (UVRR) after selective annealing were 7.7×10-10 A/cm2 and 135, respectively, which were significant improvements over the values of 1.9×10-8 A/cm2 and 19, respectively, before selective annealing. For UV sensors with Al composition of 39 %, the dark current density and UVRR were 2.3×10-6 A/cm2 and 45, respectively, after selective annealing, which were improved from the values of 6.4×10-6 A/cm2 and 11, respectively, before selective annealing. |