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.
Département MN2S, FEMTO-ST (UMR CNRS 6174), 16 Route de Gray, 25030 Besançon Cedex, France. jorge.albero@femto-st.fr
Jorge
J
Albero
Lukasz
L
Nieradko
Christophe
C
Gorecki
Heidi
H
Ottevaere
Virginia
V
Gomez
Hugo
H
Thienpont
Juha
J
Pietarinen
Birgit
B
Päivänranta
Nicolas
N
Passilly
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