English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

A measurement technique, i.e. reflectance anisotropy/difference spectroscopy (RAS/RDS), which had originally been developed for in-situ epitaxial growth control, is employed here for in-situ real-time etch-depth control during reactive ion etching (RIE) of cubic crystalline III/V semiconductor samples. Temporal optical Fabry-Perot oscillations of the genuine RAS signal (or of the average reflectivity) during etching due to the ever shrinking layer thicknesses are used to monitor the current etch depth. This way the achievable in-situ etch-depth resolution has been around 15 nm. To improve etch-depth control even further, i.e. down to below 5 nm, we now use the optical equivalent of a mechanical vernier scale– by employing Fabry-Perot oscillations at two different wavelengths or photon energies of the RAS measurement light – 5% apart, which gives a vernier scale resolution of 5%. For the AlGaAs(Sb) material system a 5 nm resolution is an improvement by a factor of 3 and amounts to a precision in in-situ etch-depth control of around 8 lattice constants.

aip advances

In-situ etch-depth control better than 5 nm with reflectance anisotropy spectroscopy (RAS) equipment during reactive ion etching (RIE): A technical RAS application