Anti-reflective nano- and micro-structures on 4H-SiC for photodiodes
1 School of Electronics and Information, Kwangwoon University, Seoul 139-701, Korea
2 Korea Electrotechnology Research Institute, Power Semiconductor Research Group, Changwon 641-120, Korea
Nanoscale Research Letters 2011, 6:236 doi:10.1186/1556-276X-6-236Published: 18 March 2011
In this study, nano-scale honeycomb-shaped structures with anti-reflection properties were successfully formed on SiC. The surface of 4H-SiC wafer after a conventional photolithography process was etched by inductively coupled plasma. We demonstrate that the reflection characteristic of the fabricated photodiodes has significantly reduced by 55% compared with the reference devices. As a result, the optical response Iillumination/Idark of the 4H-SiC photodiodes were enhanced up to 178%, which can be ascribed primarily to the improved light trapping in the proposed nano-scale texturing.