A semiconductor substrate includes a wafer including an element area and a
non-element area delineating the element area, a first layered structure
situated in the element area, a first insulating film covering the first
layered structure, and exhibiting a first etching rate with respect to an
etching recipe, a second insulating film covering the first layered
structure covered by the first insulating film in the element area, and
exhibiting a second etching rate with respect to the etching recipe, the
second etching rate being greater than the first etching rate, and a
second layered structure situated in the non-element area, wherein the
second layered structure includes at least a portion of the first layered
structure.