Germanium Wafers: July 2018

Jul 18, 2018

A three-dimensional silicon photonic crystal nanocavity with enhanced emission from embedded germanium islands

We report the realization of a silicon three-dimensional photonic crystal nanocavity containing self-assembled germanium-island emitters. The three-dimensional woodpile photonic crystal was assembled layer by layer by micromanipulation using silicon plates grown by molecular beam epitaxy. An optical nanocavity was formed in the center of the photonic crystal by introducing a point defect into one of the plates. Measurements of the filtered spontaneous emission from the Ge islands in the active plate through the localized modes of the structure directly reveal information on the evolution of the frequency and Q-factor as upper cladding plates are sequentially added. An exponential increase of the cavity-Q is observed when the number of upper cladding plates is increased up to a maximum of ten. The emission of germanium-islands within the cavity reveals several strongly polarized cavity modes with quality-factors up to ≈13 600. The emission intensity of the cavity modes is enhanced by large factors up to ≈58× as compared with the active plate outside the photonic environment.

Source:IOPscience

For more information, please visit our website: www.semiconductorwafers.net,

send us email at angel.ye@powerwaywafer.com or powerwaymaterial@gmail.com

Jul 1, 2018

Characterisation of mirror-polished Si wafers and advanced Si substrate structures using the magic mirror method

Makyoh, the magic mirror method, has proven to be one of only a few production-worthy surface characterisation tools. This technique, very simple and non-destructive, transforms latent damage, scratches, waviness and other flaws on mirror-like surfaces into visual images. It has recently been used to characterise highly finished, mirror-polished, large-diameter Si wafers for ultralarge-scale integration (ULSI) applications and III-V compound semiconductor wafers, replacing the laborious, unstable, naked-eye wafer inspection line. The authors studies have shown that the technique is also very useful for optimising various wafering processes and monitoring various process steps required to manufacture advanced substrate structures such as silicon-on-insulator, silicon-germanium alloy-on-silicon, etc for future devices. It has been successfully applied to characterise various Si wafers used in ULSI applications with the highest finish. This paper describes the recent development of the method, reviewing some of the results obtained in the evaluation of mirror-polished Si and compound semiconductor wafers and of complex substrate structures for ULSI device fabrication processes.