ABSTRACT
Subwavelength plasmonic nanostructure gratings have been identified as the promising candidates for realizing high-speed improvedresponsivity metal-semiconductor-metal photodetectors (MSM-PD). A subwavelength plasmonic nanograting is able to interact strongly with the incident light and potentially traps it inside the subsurface region of semiconductor substrates. The use of surface plasmon-assisted effects for the design of PD has led to the development of nanostructured MSM-PDs having a high responsivity-bandwidth product, well beyond that of the ordinary PIN PD, thus attracting a great deal of interest in future research. A planar MSM-PD consists of interdigitated metal fingers forming Schottky diodes on a semiconductor surface as a substrate. The practical manufacturing constraints have a strong impact on the resulting nanograting grooves or profile shapes, which in turn affect the maximum achievable light absorption enhancement in MSM-PDs and in all other devices relying on subwavelength-feature-size grating-type structures for enhancing the light capture performance.
