US Patent 7527742 Etchant, method of etching, laminate formed thereby, and device

An etchant including a halogenated salt, such as Cryolite (Na3AlF6) or potassium tetrafluoro borate (KBF4), is provided. The salt may be present in the etchant in an amount sufficient to etch a substrate and may have a melt temperature of greater than about 200 degrees Celsius. A method of wet etching may include contacting an etchant to at least one surface of a support layer of a multi-layer laminate, wherein the support layer may include aluminum oxide; or contacting an etchant to at least one surface of a support layer of a multi-layer laminate, wherein the etchant may include Cryolite (Na3AlF6), potassium tetrafluoro borate (KBF4), or both; and etching at least a portion of the support layer. The method may provide a laminate produced by growing a crystal onto an aluminum oxide support layer, and chemically removing at least a portion of the support layer by wet etch. An electronic device, optical device or combined device including the laminate is provided.