Light emission from silicon is possible in CMOS through hot carrier electroluminescence. Low conversion and low extraction efficiency remains a challenge. By using existing back-end-of-line interconnect structures it is possible to improve the extraction efficiency. Such light directing structures were analysed with the use of a focused ion beam and scanning electron microscope. It was found that it is possible to improve light extraction efficiency and directionality of the light sources through a combination of back-end-of-line structures and field oxide manipulation resulting in an improved optical path for emitted photon radiation. However, further analysis indicates that total internal reflections, scattering and electromagnetic absorption from the via plugs and metal interconnects in the back-end-of-line stack are some of the key contributors to the inefficient light extraction efficiency.

Date Published: 23 June 2014
PDF: 9 pages
Proc. SPIE 9257, Sensors, MEMS and Electro-Optical Systems, 92570N (23 June 2014); doi: 10.1117/12.2066401

Published in SPIE Proceedings Vol. 9257:
Sensors, MEMS and Electro-Optical Systems
Monuko du Plessis, Editor(s)