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 .