Method for forming fine pattern of semiconductor device
A method for forming a fine pattern of a semiconductor device comprises forming a spin-on-carbon layer over an underlying layer, forming an anti-reflection pattern including a silicon containing polymer with a first etching mask pattern, forming a photoresist pattern including a silicon containing polymer with a second etching mask pattern between elements of the first etching mask pattern, and etching the spin-on-carbon layer with the etching mask patterns to reduce the process steps and the manufacturing cost, thereby obtaining a uniform pattern profile.
1. A method for forming a fine pattern of a semiconductor device, comprising:
forming a spin-on-carbon layer over an underlying layer of a semiconductor substrate;
forming an anti-reflection film including a silicon containing polymer over the spin-on-carbon layer:
forming a first photoresist pattern over the anti-reflection film;
selectively patterning the anti-reflection film using the first photoresist pattern as an etching mask to form an anti-reflection pattern exposing the spin-on-carbon layer;
forming a second photoresist film including a silicon containing polymer over the anti-reflection pattern;
selectively patterning the second photoresist film to form a second photoresist pattern between the anti-reflection patterns; and
etching the spin-on-carbon layer using the anti-reflection patterns and the second photoresist patterns as an etching mask.
2. The method according to claim 1 , wherein the spin-on-carbon layer comprises a carbon-rich polymer wherein a carbon element is present in an amount in a range of 85 wt % to 90 wt % based on the total molecular weight of the polymer.
3. The method according to claim 1 , wherein the anti-reflection coating film comprises: a silicon-containing polymer wherein a silicon element is present in an amount in a range of 30 wt % to 80 wt % based on the total weight of the polymer; an organic solvent; and an additive selected from the group consisting of thermal acid generators and photoacid generators.
4. The method according to claim 3 , wherein the silicon-containing polymer is selected from the group consisting of siloxane compounds, silsesquioxane compounds comprising at least one of hydroxyl phenyl alkyl, alkyl, and phenyl as a substituent, and combinations thereof.
5. The method according to claim 3 , wherein the organic solvent is selected from the group consisting of ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, cyclohexanone, propyleneglycol methyl ether acetate (PGMEA), 2-heptanone, ethyl lactate, acetyl acetone, and combinations thereof.
6. The method according to claim 3 , wherein the organic solvent is present in an amount in a range of about 500 parts by weight to 10,000 parts by weight of 100 parts by weight of the silicon-containing polymer; and
the additive is present in an amount ranging from about 0.1 to 10 parts by weight of 100 parts by weight of the silicon-containing polymer.
7. The method according to claim 1 , wherein the first photoresist patterns are formed using a chemically amplified photoresist composition.
8. The method according to claim 1 , wherein the chemically amplified photoresist composition comprises a photoacid generator, an organic solvent, and a chemically-amplified photoresist polymer as a base resin.
9. The method according to claim 1 , wherein the anti-reflection coating film is patterned by a dry etching process employing a source gas comprising CF 4 , CHF 3 , O 2 and Ar.
10. The method according to claim 1 , further comprising removing the first photoresist pattern before forming the second photoresist film.
11. The method according to claim 10 , comprising removing the first photoresist pattern by using a thinner.
12. The method according to claim 1 , wherein the second photoresist film has the thickness as same as or greater than the anti-reflection coating pattern; and
the second photoresist film has a thickness as same as or less than the first photoresist pattern thickness.
13. The method according to claim 1 , wherein the second photoresist film comprises: a silicon-containing polymer wherein a silicon element is present in an amount in a range of 30 wt % to 80 wt % based on the total weight of the polymer; an organic solvent; and a photoacid generator.
14. The method according to claim 13 , wherein the silicon containing polymer includes a polymerization repeating unit of Formula 1:
wherein R is hydrogen or methyl; R 1 is a linear or branched C 2 -C 10 alkylene; R 2 , R 3 and R 4 each independently are a C 1 -C 3 alkoxy group; R 5 is selected from the group consisting of OH, H, a C 1 -C 10 alkyl and an acid labile protecting group; and the relative ratio of the repeating unit number of a:b:c is 0.3-1:1-3:1.
15. The method according to claim 13 , wherein the organic solvent is selected from the group consisting of ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, cyclohexanone, propyleneglycol methyl ether acetate (PGMEA), 2-heptanone, ethyl lactate, acetyl acetone and combinations thereof.
16. The method according to claim 13 , wherein the organic solvent is present in an amount ranging from about 500 parts by weight to 10,000 parts by weight of 100 parts by weight of the silicon-containing polymer; and
the photoacid generator is present in an amount ranging from about 0.1 parts by weight to 10 parts by weight of 100 parts by weight of the silicon-containing polymer.
17. The method according to claim 1 , wherein the spin-on-carbon layer is etched by an etching process employing a source gas comprising: (i) O 2 and (ii) at least one of N 2 , and H 2 .
18. The method according to claim 1 , wherein the patterning the second photoresist film is performed by an ArF, KrF or EUV lithography process.