Photonic Crystal Microcavities in a Microelectronics 45nm SOI CMOS Technology

TL;DR

This paper reports the first integration of photonic crystal microcavities into a standard 45nm SOI CMOS process without modifications, achieving high quality factors and demonstrating compatibility with microelectronics fabrication.

Contribution

It introduces monolithic integration of photonic crystal microcavities in advanced CMOS technology with no process changes, enabling photonics-electronics co-integration.

Findings

Achieved quality factors up to 100,000 for 1520nm cavities.

Demonstrated cavity designs at 1520nm and 1180nm wavelengths.

Implemented evanescent coupling geometry for improved cavity-waveguide interaction.

Abstract

We demonstrate the first monolithically integrated linear photonic crystal microcavities in an advanced SOI CMOS microelectronics process (IBM 45nm 12SOI) with no in-foundry process modifications. The cavities were integrated into a standard microelectronics design flow meeting process design rules, and fabricated alongside transistors native to the process. We demonstrate both 1520nm wavelength and 1180nm cavity designs using different cavity implementations due to design rule constraints. For the 1520nm and 1180nm designs, loaded quality factors of 2,000 and 4,000 are measured, and intrinsic quality factors of 100,000 and 60,000 are extracted. We also demonstrate an evanescent coupling geometry which decouples the cavity and waveguide-coupling design.