High-Aspect-Ratio Micropatterning Capabilities into Thick Resist Layers Using Deep X-ray Lithography at SyLMAND

摘要

Most current and next-generation lithography techniques aim at highest lateral resolution patterning of very shallow resist layers, often for application in micro electronics processing sequences. Extreme Ultra Violet (EUV) Lithography is an example of such techniques [1] and is the focus of this special SRN issue. A different synchrotron-radiation-based micro lithography technique with distinctly different properties, applications, and technical requirements is deep X-ray lithography (XRL). In XRL, the focus commonly is on patterning thick resist layers (typically, up to hundreds of micrometers or even millimeters) with high aspect ratios (ratio of thickness to minimum lateral feature size; up to 100:1 and higher), and smooth and vertical sidewalls, at reduced requirements on lateral resolution. XRL can be combined with subsequent process steps of the LIGA process (German acronym for lithography, electroplating, and replication) [2] to obtain a wider variety of patterned materials (including polymers, metals, and ceramics) and to reduce the cost per patterned component by mass replication rather than individual lithography.