Fabrication of spherical microlenses by a combination of isotropic wet etching of silicon and molding techniques.
We report a novel process technology of hemispherical shaped microlenses, using isotropic wet etching of silicon in an acid solution to produce the microlenses molds. Governed by process parameters such as temperature and etchant concentration, the isotropic wet etching is controlled to minimize various defects that appear during the molding creation. From the molds, microlenses are fabricated in polymer by conventional replication techniques such as hot embossing and UV-molding. The characterization of molds and measurements of replicated microlenses demonstrate high smoothness of the surfaces, excellent repeatability of mold fabrication and good optical properties. Using the proposed method, a wide range of lens geometries and lens arrays can be achieved.
Albero
Jorge
J
Département MN2S, FEMTO-ST (UMR CNRS 6174), 16 Route de Gray, 25030 Besançon Cedex, France. jorge.albero@femto-st.fr
Nieradko
Lukasz
L
Gorecki
Christophe
C
Ottevaere
Heidi
H
Gomez
Virginia
V
Thienpont
Hugo
H
Pietarinen
Juha
J
Päivänranta
Birgit
B
Passilly
Nicolas
N
D016880:Anisotropy; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D008904:Miniaturization; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012825:Silicon / Q000737:chemistry*; D017155:Wettability
D012825:Silicon