Etching structure

Abstract

An etching structure includes a substrate, a to be etched filmcovering the principal surface of the substrate, and an exposure region exposing the principal surface of the substrate and obtained by removing a part of the to be etched film. A region of the to be etched film constitutes a peripheral region surrounding the exposure region. Another region of the to be etched film outside the peripheral region constitutes a flat region. The film thickness of the to be etched film increases as the distance from the exposure region increases, such that the inclination of the outline of the cross section of the to be etched film that exists within the peripheral region decreases as the distance from the exposure region increases. The to be etched film has a side wall that extends perpendicularly to the principal surface at a boundary between the peripheral region and the flat region.

1 . An etching structure comprising:
 a substrate;   a to be etched film covering the principal surface of said substrate;   an exposure region exposing said principal surface of said substrate and obtained by removing a part of said to be etched film;   a peripheral region constituting a region of said to be etched film and surrounding said exposure region thereby; and   a flat region constituting a region of said to be etched film and existing outside said peripheral region,   wherein the film thickness of said to be etched film increases as the distance from said exposure region increases such that the inclination of the outline of the cross-section of said to be etched film that exists within said peripheral region decreases as the distance from said exposure region increases; and   wherein said to be etched film is provided with a side wall that extends perpendicularly to said principal surface at a boundary between said peripheral region and said flat region.   
   
   
       2 . The etching structure according to  claim 1 , wherein the height of said side wall in a direction perpendicular to said principal surface is at least 50 nm.