Abstract
An extended set of coupled wave equations were derived to
describe non-idealized lamellar multilayer grating structures with properties
as obtained with state-of-the-art fabrication techniques. These generalized
equations can include all relevant effects describing the influence
of passivation and contamination layers, non-rectangular lamel profiles
and sidewall scalloping. The calculations showed that passivation and
contamination plays an important role in that it may significantly reduce
peak reflectivity. However, we also derived a condition for layer thicknesses
having negligible effects. Slightly positive tapered lamel profiles are
shown to further reduce the bandwidth as compared to a rectangular lamel
profile, whereas negative tapers significantly increased the bandwidth. The
influence of intriguing effects, such as the sidewall scalloping caused by
Bosch Deep Reactive Ion Etching, are also modeled. We identified the
signature of such scalloping as additional side peaks in the reflectivity spectrum
and present parameters with which these can be effectively suppressed.
Original language | English |
---|---|
Pages (from-to) | 13105-13117 |
Journal | Optics express |
Volume | 21 |
Issue number | 11 |
DOIs | |
Publication status | Published - 2013 |