Deep Dry-etch of Silica in a Helicon Plasma Etcher for Optical Waveguide Fabrication

dc.contributor.authorLi, Wei
dc.contributor.authorBulla, Douglas
dc.contributor.authorLove, John
dc.contributor.authorLuther-Davies, Barry
dc.contributor.authorCharles, Christine
dc.contributor.authorBoswell, Roderick
dc.date.accessioned2015-12-13T22:45:33Z
dc.date.available2015-12-13T22:45:33Z
dc.date.issued2005
dc.date.updated2015-12-11T10:23:43Z
dc.description.abstractDry-etch of SiO2 layers using a CF4 plasma in a helicon plasma etcher for optical waveguide fabrication has been studied. Al2O3 thin films, instead of the conventional materials, such as Cr or photoresist, were employed as the masking materials. The Al2O3 mask layer was obtained by periodically oxidizing the surface of an Al mask in an oxygen plasma during the breaks of the SiO2 etching process. A relatively high SiO2/Al2O3 etching selectivity of ∼100:1, compared with a SiO2/Al selectivity of ∼15:1, was achieved under certain plasma condition. Such a high etching selectivity greatly reduced the required Al mask thickness from over 500 nm down to ∼100nm for etching over 5-μm-thick silica, which make it very easy to obtain the mask patterns with near vertical and very smooth sidewalls. Accordingly, silica wavegudies with vertical sidewalls whose roughness was as low as 10 nm were achieved. In addition, the mechanism of the profile transformation from a mask to the etched waveguide was analyzed numerically; and it was found that the slope angle of the sidewalls of the mask patterns only needed to be larger than 50° for achieving vertical sidewalls of the waveguides, if the etching selectivity was increased to 100.
dc.identifier.issn0734-2101
dc.identifier.urihttp://hdl.handle.net/1885/79837
dc.publisherAmerican Institute of Physics (AIP)
dc.sourceJournal of Vacuum Science and Technology A
dc.subjectKeywords: Dry etching; Photoresists; Surface roughness; Thin films; Waveguides; Conventional materials; Etching selectivity; Waveguide fabrication; Silica
dc.titleDeep Dry-etch of Silica in a Helicon Plasma Etcher for Optical Waveguide Fabrication
dc.typeJournal article
local.bibliographicCitation.issue1
local.bibliographicCitation.lastpage150
local.bibliographicCitation.startpage146
local.contributor.affiliationLi, Wei, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationBulla, Douglas, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationLove, John, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationLuther-Davies, Barry, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationCharles, Christine, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationBoswell, Roderick, College of Physical and Mathematical Sciences, ANU
local.contributor.authoremailu7501719@anu.edu.au
local.contributor.authoruidLi, Wei, u4026391
local.contributor.authoruidBulla, Douglas, u4031353
local.contributor.authoruidLove, John, u7501719
local.contributor.authoruidLuther-Davies, Barry, u7601418
local.contributor.authoruidCharles, Christine, u4025692
local.contributor.authoruidBoswell, Roderick, u8000743
local.description.notesImported from ARIES
local.description.refereedYes
local.identifier.absfor020501 - Classical and Physical Optics
local.identifier.ariespublicationMigratedxPub8211
local.identifier.citationvolume23
local.identifier.doi10.1116/1.1842114
local.identifier.scopusID2-s2.0-31044456005
local.identifier.uidSubmittedByMigrated
local.type.statusPublished Version

Downloads