Mask, method of producing the same, and method of producing semiconductor device

A method of producing a mask comprising the steps of:

• forming a support layer via an assist layer at one side of a substrate;
• forming a thin film on said support layer;
• removing a portion of said substrate at another side of said substrate to expose a portion of said assist layer and forming a support frame composed of a portion of said substrate around exposure portions of said assist layer;
• forming holes at a portion of said thin film except portions of said support frame through which a charged particle beam passes;
• feeding an etching solution or an etching gas via said holes to said support layer to isotropically etch and form apertures at a larger size than said holes at least at portions of said holes in said support layer;
• and
• removing said assist layer except portions of said support frame.

A method of producing a mask comprising the steps of:

• forming a thin film at one side of a substrate;
• forming a support layer on said substrate;
• removing a portion of said substrate at another side-of said substrate to expose a portion of said thin film and form a support frame composed of a portion of said substrate around exposure portions of said thin film;
• forming an assist layer on said support layer;
• forming holes at a portion of said thin film except portions of said support frame through which a charged particle beam passes;
• feeding an etching solution or an etching gas via said holes at said support layer to etch isotropically and form apertures at a larger size than said holes at least at portions of said holes in said support layer;
• and
• removing said assist layer.

A method of producing a semiconductor device having a step of irradiating a charged particle beam on a photosensitive surface via a mask on which a predetermined mask pattern is formed to transfer said mask pattern on said photosensitive surface comprising using a mask having:

• a thin film;
• holes formed by said mask pattern in said thin film through which a charged particle beam passes;
• a support layer formed at one side of said thin film;
• apertures formed at a larger size than said holes at least at portions of said holes in said support layer;
• a support frame for supporting said thin film formed via an assist layer at least on a portion of said thin film except at said holes;
• and
• said assist layer having resistance to an etching solution or an etching gas for forming said apertures at said support layer.

A method of producing a semiconductor device having a step of irradiating a charged particle beam on a photosensitive surface via a mask on which a predetermined mask pattern is formed to transfer said mask pattern on said photosensitive surface comprising using a mask having:

• a thin film;
• holes formed at said thin film through which a charged particle beam passes;
• a support layer formed at one side of said thin film;
• apertures formed at a larger size than said holes at least at portions of said holes in said support layer;
• and
• a support frame for supporting said thin film formed at least at a portion of said thin film except at said holes.