Gray scale x-ray mask
AssigneeSandia National Laboratories
InventorsAlfredo M. Morales, Marcela Gonzales
Life of this patent
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Abstract
The present invention describes a method for fabricating an embossing tool or an x-ray mask tool, providing microstructures that smoothly vary in height from point-to-point in etched substrates, i.e., structure which can vary in all three dimensions. The process uses a lithographic technique to transfer an image pattern in the surface of a silicon wafer by exposing and developing the resist and then etching the silicon substrate. Importantly, the photoresist is variably exposed so that when developed some of the resist layer remains. The remaining undeveloped resist acts as an etchant barrier to the reactive plasma used to etch the silicon substrate and therefore provides the ability etch structures of variable depths.
Claims8
An x-ray mask tool, comprising:
- a silicon substrate having a first thickness, a top surface, and a bottom surface substantially parallel to said top surface;
- and
- a three-dimensional metal structure embedded into said silicon substrate and about flush with said top surface, said three-dimensional metal structure comprising a second thickness less than said first thickness, and one or more regions, wherein said second thickness varies continuously across a length and width of said three-dimensional metal structure thereby providing a floor surface in each of said one or more regions which varies in a curvilinear manner.
Dependencies are inferred from the claim text.