Methods for forming pattern using electron beam and cell masks used in electron beam lithography

A method for forming a pattern using an electron beam lithography apparatus, the method comprising:

• forming a negative resist layer on a substrate, the negative resist layer including a first region, a second region shrinking to a distance from the first region, and a third region surrounding the first region;
• irradiating a region in the first region excluding the second region with an electron beam at a first dose;
• irradiating the second region with electron beam at a second dose less than the first dose;
• and
• forming a resist pattern remaining in the first region by removing the negative resist of the third region.

A cell mask comprising:

• a mask substrate;
• a shielding region disposed on the mask substrate;
• a transmitting region extending a distance from the shielding region;
• and
• a gray pattern region disposed around the transmitting region, the gray pattern region including patterns having a pitch smaller than a resolution limit of an electron beam lithography apparatus.

A method for forming a pattern using an electron beam lithography apparatus, the method comprising:

• forming a resist layer on a substrate, the resist layer including a first region and a second region;
• modifying a size of the second region to create at least one third region;
• irradiating the second region excluding the at least one third region with an electron beam having a first dose;
• and
• irradiating the at least one third region with the electron beam having a second dose, wherein
• the first dose is less than the second dose.