GaN metal-semiconductor-metal photodetectors with low-temperature-GaN cap layers and ITO metal contacts

• Published in: IEEE electron device letters Vol. 24; no. 4; pp. 212 - 214
• Main Authors: Chang, S.J., Lee, M.L., Sheu, J.K., Lai, W.C., Su, Y.K., Chang, C.S., Kao, C.J., Chi, G.C., Tsai, J.M.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2003; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Dark current; Devices; Gallium arsenide; Gallium nitride; Gallium nitrides; III-V semiconductor materials; Indium tin oxide; Nitrides; Photodetectors; Schottky barriers; Schottky diodes; Semiconductor diodes; Temperature
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2003.812147

Nitride-based metal-semiconductor-metal (MSM) photodetectors (PDs) with low-temperature (LT) gallium nitride (GaN) cap layers and indium-tin-oxide (ITO) metal contacts were successfully fabricated. It was found that we could achieve three orders of magnitude smaller dark current by the introduction of the LT-GaN layer. For the PDs with LT-GaN cap layers, the maximum responsivity at 350 nm was found to be 0.1 and 0.9 A/W when the device was biased at 1 and 5 V, respectively. Operation speed of PDs with LT-GaN cap layers was also found to be faster than that of conventional PDs without LT-GaN cap layers.