Patent ID: 8273659

Claim:
A method of etching a material, wherein the etching is restricted to an etch pattern area on an unmasked exposed surface of the material, the etch pattern area extending over only a part of the unmasked exposed surface, the method comprising: (a) providing at least a first component required for the etching of the material as a surface layer extending over a region of the unmasked exposed surface of the material, the surface layer being a gel or solid layer covering at least the etch pattern area; (b) providing at least one deposition composition comprising one or more further components required for the etching of the material; and (c) applying the at least one deposition composition over the region of the unmasked exposed surface of the material in a pattern corresponding to the etch pattern area; whereby the first component required for etching the material reacts with the one or more further components required for etching of the material to form an etchant to etch the material only in the etch pattern area.