Negative resist for X-ray and electron beam lithography and method of using same
AssigneeBell Telephone Laboratories, Incorporated
InventorGary Newton Taylor
Life of this patent
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Abstract
A class of chlorinated or brominated polymeric negative resists for high resolution X-ray or electron lithographic processes is described. Chlorine and bromine atoms have a generally high mass absorption coefficient for X-rays and can be incorporated into the polymer in high weight percents. The chlorinated resists are especially sensitive to the 4.37 Angstrom characteristic X-rays from a Pd target.
Claims41
Article comprising a substrate coated with a radiation sensitive material, characterized in that said material consists essentially of a polymer prepared from a first monomer selected from the group consisting of monomers represented by the formula ##STR3## where R.sub.1 is selected from the group consisting of H and CH.sub.3, X is ##STR4## and m is 0 or 1, and R.sub.2 is an alkyl group with the formula C.sub.n H.sub.2n-x+1 Y.sub.x where n and x are equal to or greater than one, x is equal to or less than 2n + 1, and Y is selected from the group consisting of chlorine and bromine, together with a second monomer said second monomer being a vinyl monomer, said first monomer forming between 50 percent and 100 percent by weight, of the polymer.
Process for pattern delineating a substrate coated with a negative resist material comprising the steps of
- exposing selected portions of said resist material to radiation which causes said exposed portions to become less easily removable with respect to the unexposed portions, in which said resist consists essentially of a polymer;
- removing the unexposed portions;
- and
- processing the pattern delineated resist and substrate with processing steps that alter the bared substrate areas, characterized in that said polymer consists essentially of a polymer prepared from a first monomer selected from the group consisting of monomers represented by the formula ##STR5## where R.sub.1 is selected from the group consisting of H and CH.sub.3, X is ##STR6## and m is 0 or 1, and R.sub.2 is an alkyl group with the formula C.sub.n H.sub.2n-x+1 Y.sub.x where n and x are equal to or greater than one, x is equal to or less than 2n+1, and Y is selected from the group consisting of chlorine and bromine, together with a second monomer, said second monomer being a vinyl monomer, said first monomer forming between 50 percent and 100 percent by weight of the polymer.
Dependencies are inferred from the claim text.