Soft Lithography Replication of a Bioinspired Unidirectional Wicking Channel
Lithography, dry etching and repLication
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FRAUNHOFER INSTITUTE FOR APPLIED OPTICS AND PRECISION ENGINEERING IOF combination of Lithography, dry etching and repLication 1 Precise mirror arrays in silicon. 2 RIE transferred lens array in glass. 3 Detail of high fill factor lens array maste- red by lithography, reflow and RIE. Proportional reactive ion etching (RIE) transfer of reflow photoresist structures is a well established microlens fabrication technology. Interesting additional features can be generated by a suitable combination of this technology with polymer replication. Concave microlenses in SiO 2 and Si Reflow photoresist structures are typically convex, but the surface can be inverted introducing an additional polymer replica- tion step. Accordingly, the inverted lenses can be transferred to the subjacent silicon or glass substrate. One example is the generation of precise concave mirror arrays in silicon. Aspherical lens profiles The surface of photoresist reflow lenses is typically spherical. A desired aspherical (elliptical, parabolic) profile can be achieved using a suitable RIE transfer process. The generated structures can serve as master in a subsequent replication process. Lens arrays with 100% fill factor Typically, the fill factor of standard photo- resist reflow lens arrays is reduced by the packing density of circular lens apertures and by the resolution of photolithography. Because of its isotropic etching behavior a subsequent RIE step can influence the fill factor. This enables i.e. the generation of hexago- nally packed lenslets with 100% fill factor which can again serve as a replication master structure. Fraunhofer Institute for Applied Optics and Precision Engineering IOF Albert-Einstein-Straße 7 07745 Jena Director Prof. Dr. Andreas Tünnermann Head of Business Unit Optical Components and Systems Prof. Dr. Uwe Zeitner Contact Dr. Peter Dannberg Phone +49 3641 807-420 [email protected] www.iof.fraunhofer.de 1 2 3
Transcript of Lithography, dry etching and repLication
F R A U N H O F E R I N S T I T U T E F O R A P P L I E D O P T I C S A N D P R E C I S I O N E N G I N E E R I N G I O F
combination of Lithography, dry etching and repLication
1 Precisemirrorarraysinsilicon.
2 RIEtransferredlensarrayinglass.
3 Detailofhighfillfactorlensarraymaste-
redbylithography,reflowandRIE.
Proportional reactive ion etching (RIE)
transfer of reflow photoresist structures
is a well established microlens fabrication
technology.
Interesting additional features can be
generated by a suitable combination of this
technology with polymer replication.
Concave microlenses in SiO2 and Si
Reflow photoresist structures are typically
convex, but the surface can be inverted
introducing an additional polymer replica-
tion step. Accordingly, the inverted lenses
can be transferred to the subjacent silicon
or glass substrate. One example is the
generation of precise concave mirror arrays
in silicon.
Aspherical lens profiles
The surface of photoresist reflow lenses
is typically spherical. A desired aspherical
(elliptical, parabolic) profile can be achieved
using a suitable RIE transfer process. The
generated structures can serve as master in
a subsequent replication process.
Lens arrays with 100% fill factor
Typically, the fill factor of standard photo-
resist reflow lens arrays is reduced by the
packing density of circular lens apertures
and by the resolution of photolithography.
Because of its isotropic etching behavior a
subsequent RIE step can influence the fill
factor.
This enables i.e. the generation of hexago-
nally packed lenslets with 100% fill factor
which can again serve as a replication
master structure.
Fraunhofer Institute for Applied
Optics and Precision Engineering IOF
Albert-Einstein-Straße 7
07745 Jena
Director
Prof. Dr. Andreas Tünnermann
Head of Business Unit Optical
Components and Systems
Prof. Dr. Uwe Zeitner
Contact
Dr. Peter Dannberg
Phone +49 3641 807-420
www.iof.fraunhofer.de
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