Integrating 3D PIN germanium detectors with high-k ALD fabricated slot waveguides

A novel device technology for photonics integrated circuits (PICs) is presented. In this work germanium PIN photodetectors are embedded in back-end deposited high-k slot waveguides. The waveguides are fabricated using chemical vapor deposited amorphous silicon and atomic layer deposition of Al
₂
O
₃
thin films. The germanium PIN stack is selectively grown on a bulk silicon substrate. The detectors are butt coupled to the slot waveguides. Using our selective germanium growth and interconnect technology we study a 3D multilayer photonic integration for CMOS back-end of the line (BEOL) process. Finally we demonstrate the fabrication of a photonic chip deploying this technology platform.