Si moulds for glass and polymer microlenses replication

Abstract

The concept of the fabrication process of glass microlenses integrated with silicon and polymer replicas is presented. These kinds of microlenses are formed using a silicon master which is wet etched in alkaline solutions (anisotropic etching) and/or in acid solutions (isotropic etching). The control of the times and the selection of the solutions, joined with the designs of the mask for conventional photolithography and the quality of the silicon wafers are the key for obtaining the desired shapes and sizes. The fabricated moulds are used to replicate microlenses in polymer by the standard well known replication technologies and also to fabricate glass microlenses integrated on a silicon frame.

Integrated glass lenses fabrication for parallel interferometric inspection systems of MEMS and MOEMS

“…One of them works as a low coherent interferometer, allowing the static measurement of deformations and shape of the structure, while the other one works as a laser interferometer, able to determine the dynamic characteristics of the structure, such as resonance frequency. In here we will focus on the optics fabrication for the low coherent interferometer by adapting glass molding techniques [3]. *jorge.albero@femto-st.fr; femto-st.fr Following that principle, a micro-optical probing wafer based on the Mirau interferometer configuration [4], is aligned with the wafer under test (Figure 1).…”

Design of a micro-optical low coherent interferometer array for the characterisation of MEMS and MOEMS

“…The back surface of the glass is polished to reach the needed thickness and optical quality of the glass substrate. Finally, the microlenses are released by etching away the silicon [6]. An alternative technique is the direct moulding of polymer.…”

“…As a first step, lens moulds are fabricated by chemical wet etching on a silicon wafer. The large size and sag implies a challenging multi-step etching process, combining anisotropic and isotropic wet etching of silicon [5,6].…”

Fabrication of Microlens by Nd:YVO4 laser irradiation of glass frit layers.

“…This is an important advantage for bio-analysis applications. [2,3] We fabricate flat surfaces with the desired structure using a Nd:YVO 4 laser for writing directly on a glass frit layer deposited over a glass substrate. The deposited layer is based on PbO-SIO4-B2O3 glass frits, which were applied by conventional methods on commercial glass substrates.…”