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US 7,070,702 B1Granted
Pattern formation method using light-induced suppression of etching
AssigneeQinetiq Limited
InventorsRobert W Eason, Ian E Barry, Peter G R Smith, Graeme W Ross
Life of this patent
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Abstract
A method of selectively etching a substrate (1) comprises applying etchant (4) at a surface of the substrate and illuminating an area of the surface with light from a light source (7), whereby etching is at least partially inhibited in the illuminated area (18) of the substrate. Preferably LiNbO3 is patterned in HF KOH, or HF═HNO3 solutions by selective illumination using UV laser light with 300 to 1000 mn wavelength, thereby allowing for interferometric or holographic structures to be formed.
Claims13
A method of selectively etching a substrate, the method comprising the steps of;
- applying etchant at a surface of the substrate;
- and
- illuminating an area of the surface with light from a light source, wherein the light is transmitted through the substrate to the surface and etching is at least partially inhibited by optical liberation of charge in the illuminated area of the substrate.
Dependencies are inferred from the claim text.