Use of tin thin film for bonding and as masking film
AssigneeUniversity of South-Eastern Norway
InventorsAvisek Roy, Eivind Bardalen, Per Alfred Øhlckers
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Abstract
The present invention relates to a method for micromachining a silicon structure especially for SLID bonding, comprising the steps of preparing a silicon wafer with a metal pattern on said silicon, said silicon being exposed outside said pattern, the metal pattern at least having an upper surface consisting of Sn. The method comprising a step of DRIE etching of the structure for etching cavities in said exposed silicon wafer essentially without etching said Sn top layer. The method also relates to the use of Sn as an etching mask in micromachining av silicon structures.
Claims8
A method for micromachining a silicon structure, comprising:
- preparing a silicon wafer with a metal pattern on the silicon, the silicon being exposed outside the metal pattern, the metal pattern at least having an upper surface consisting of Sn;
- Deep Reactive Ion etching (“DRIE”) of the structure for etching cavities in the exposed silicon wafer essentially without etching the Sn top layer;
- wherein an under seal metal (“USM”) layer has been provided between the silicon wafer and the metal pattern;
- and
- before the DRIE, performing a wet etching removing the USM layer outside thus exposing the silicon outside the metal pattern, metal of the USM layer being at least one of Au and TiW.
Dependencies are inferred from the claim text.