Towards a CMOS compatible refractive index sensor: cointegration of TiN nanohole arrays and Ge photodetectors in a 200 mm wafer silicon technology.

In this work, we present the monolithic integration of a TiN nanohole array and a Ge photodetector towards a CMOS compatible fabrication of a refractive index sensor in a 200 mm wafer silicon technology. We developed a technology process that enables fabrication with high yields of around 90%. Ge photodetectors with a Ge layer thickness of 450 nm and an area of 1600 µm (40 µm x 40 µm) show dark current densities of around 129 mA/cm and responsivities of 0.

Strongly enhanced sensitivities of CMOS compatible plasmonic titanium nitride nanohole arrays for refractive index sensing under oblique incidence.

Titanium nitride (TiN) is a complementary metal-oxide-semiconductor (CMOS) compatible material with large potential for the fabrication of plasmonic structures suited for device integration. However, the comparatively large optical losses can be detrimental for application. This work reports a CMOS compatible TiN nanohole array (NHA) on top of a multilayer stack for potential use in integrated refractive index sensing with high sensitivities at wavelengths between 800 and 1500 nm.