Patent ID: 7560040

Claim:
An etching method for etching away a prescribed etch portion of a material to be shaped to form an etch product, via an etching treatment in which an outline of the etch product is formed by etching a portion of the prescribed etch portion, and via an etching treatment in which a portion of a groove formation portion of the prescribed etch portion of the material to be shaped is etched away so as to form a depressed groove in the material to be shaped, said etching method for shaping an etch product comprising: applying an etch retardant layer which only covers a surface of the groove formation portion of the prescribed etch portion of the material to be shaped so as to define an outer periphery of the etch product; outline etching in the presence of the etch retardant layer, to remove a portion of the prescribed etch portion of the material to be shaped that is outside the outer periphery of the etch product so as to form the outline of the etch product; dissolving at least a portion of the etch retardant layer which covers the groove formation portion, after starting and simultaneously with said outline etching; and groove etching to remove a portion of the groove formation portion of the prescribed etch portion of the material to be shaped which is no longer covered by the etch retardant layer so as to form the depressed groove in the groove formation portion to obtain the etch product, said groove etching being stopped at an etch stop position according to a pattern of the depressed groove, wherein the portion of the prescribed etch portion to be removed during said outline etching and the portion of the groove formation portion to be removed during said groove etching are separate portions of the material to be shaped such that the portion of the groove formation portion to be removed during said groove etching includes at least an outermost surface of the material to be shaped, and wherein a pattern of the etch retardant layer is set in advance such that an amount of said groove etching performed before said groove etching is stopped is substantially equal to a depressed groove depth which is also set in advance.