Method of varying etch selectivities of a film

摘要

A method of patterning a crystalline film. A crystalline film having a degenerate lattice comprising first atoms in a first region and a second region is provided. Dopants are substituted for said first atoms in said first region to form a non-degenerate crystalline film in said first region. The first region and the second region are exposed to a wet etchant wherein the wet etchant etches the degenerate lattice in said second region without etching the non-degenerate lattice in the first region.