Patent ID: 7700269

Claim:
A method of forming a stacked structure in an electronic material, comprising: coating at least one target material layer on a substrate of the electronic material; forming a mask layer by coating a positive photoresist having a polymer on the substrate, the polymer comprising at least 50 mole % of monomers having a structure selected from the group consisting of Fonnulae 1 to 3; first baking the mask layer at a first temperature; exposing the mask layer to light with a predetermined pattern; second baking the mask layer at a second temperature; developing the mask layer to form an etch window in the mask layer; etching the target material layer through the etch window; repeating at least twice the exposing to the developing; and removing the mask layer: where R 1 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 2 is an alkyl group having 1 to 6 linear or cyclic carbon atoms, and R 3 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms; where R 1 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 2 is an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 3 and R 4 are independently hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, and R 1 and R 2 , or R 1 and either R 3 or R4, or R 2 and either R 3 or R 4 are joined to form a 5-, 6-, or 7-membered ring; and where R 1 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 2 is an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 3 and R 4 are independently hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, and R 1 and R 2 , or R 1 and either R 3 or R4, or R 2 and either R 3 or R 4 are joined to form a 5-, 6-, or 7-membered ring.