CMOS compatible near-infrared sensor system
A surface plasmon-based photodetector includes: a silicon substrate; a grating in contact with a surface of the silicon substrate, in which the grating forms a Schottky diode with the semiconductor substrate; and a complementary-metal-oxide-semiconductor (CMOS) sample and hold stage as well as an analog-to-digital circuit (ADC) in the silicon substrate and arranged to detect electrical current generated at the Schottky diode.
1 . A surface plasmon-based photodetector comprising:
a silicon substrate;
a grating in contact with a surface of the silicon substrate, wherein the grating forms a Schottky diode with the silicon substrate; and
a complementary-metal-oxide-semiconductor (CMOS) circuit comprising a sample and hold circuit and an analog-to-digital circuit (ADC) in the silicon substrate, wherein the CMOS circuit is arranged to detect electrical current generated at the Schottky diode.
2 . The surface-plasmon based photodetector of claim 1 , wherein the grating is aluminum.
3 . The surface-plasmon based photodetector of claim 1 , wherein the grating is tungsten.
4 . The surface-plasmon based photodetector of claim 1 , wherein the grating is platinum.
5 . The surface-plasmon based photodetector of claim 1 , wherein the grating is gold.
6 . The surface-plasmon based photodetector of claim 1 , wherein the grating comprises a plurality of rings.
7 . The surface-plasmon based photodetector of claim 1 , wherein the grating comprises a plurality of pillars arranged in a two-dimensional array.
8 . The surface-plasmon based photodetector of claim 1 , wherein the CMOS circuit is laterally displaced from the grating without being positioned directly underneath the grating.
9 . The surface-plasmon based photodetector of claim 1 , wherein the CMOS circuit is no more than 1 micron away from an edge of the grating.
10 . The surface-plasmon based photodetector of claim 1 , wherein the ADC comprises a sigma-delta A-to-D converter.
11 . The surface-plasmon based photodetector of claim 1 , wherein the sample and hold circuit comprises a differential amplifier circuit.
12 . The surface-plasmon based photodetector of claim 11 , wherein the differential amplifier circuit comprises multiple differential stages.