Compositions and processes for photolithography
View Patent ↗Topcoat layer compositions are provided that are applied above a photoresist composition. The compositions find particular applicability to immersion lithography processing.
1. A composition suitable for use in forming a topcoat layer over a layer of photoresist, the composition comprising:
a first matrix resin comprising one or more acidic functional groups;
a second additive resin that is different from and substantially immiscible with the first resin, the second resin comprising as polymerized units a monomer of the formula (I):
wherein R 1 is hydrogen or a C1 to C6 optionally substituted alkyl or fluoroalkyl group, R 2 is an optionally substituted cycloalkyl or branched alkyl group, R 3 is an optionally substituted alkylene group and R 4 and R 5 are independently C1 to C4 fluoroalkyl groups;
wherein the second resin has a lower surface energy than a surface energy of the first resin; and
a mixture of solvents effective to achieve phase separation of the additive resin from other resin(s) in the composition during spin-coating.
2. The composition of claim 1 , wherein R 2 is an optionally substituted C3 to C6 isoalkyl group.
3. The composition of claim 1 , wherein the composition, when used in an immersion lithography process with water as the immersion fluid, provides a receding contact angle of greater than 72°.
4. The composition of claim 1 , wherein the mixture of solvents comprises a dialkyl glycol monoalkyl ether.
5. The composition of claim 1 , wherein the second resin further comprises as polymerized units a second monomer comprising one or more acid-labile groups.
6. The composition of claim 1 , wherein the mixture of solvents comprises: a primary solvent and an additive solvent having a boiling point higher than that of the primary solvent, wherein the primary solvent has a boiling point of from 120 to 140° C. and the additive solvent has a boiling point of from 170 to 200° C.
7. The composition of claim 6 , wherein the additive solvent is present in an amount of from 3 to 15 wt % based on the mixture of solvents.
8. A composition suitable for use in forming a topcoat layer over a layer of photoresist, the composition comprising:
a first matrix resin comprising one or more acidic functional groups;
a second additive resin that is different from the first resin, the second resin comprising as polymerized units a monomer of the formula (I):
wherein R 1 is hydrogen or a C1 to C6 optionally substituted alkyl or fluoroalkyl group, R 2 is an optionally substituted cycloalkyl or branched alkyl group, R 3 is an optionally substituted alkylene group and R 4 and R 5 are independently C1 to C4 fluoroalkyl groups;
wherein the second resin has a lower surface energy than a surface energy of the first resin; and
a mixture of solvents effective to achieve phase separation of the additive resin from other resin(s) in the composition during spin-coating, wherein the mixture of solvents comprises: a primary solvent and an additive solvent having a boiling point higher than that of the primary solvent, wherein the primary solvent has a boiling point of from 120 to 140° C. and the additive solvent has a boiling point of from 170 to 200° C.; wherein the mixture of solvents comprises: a dialkyl glycol monoalkyl ether; an alcohol; and an alkyl ether or an alkane.
9. A method of processing a photoresist composition, comprising:
(a) applying a photoresist composition over a substrate to form a photoresist layer;
(b) applying over the photoresist layer a topcoat composition, the composition comprising:
a first matrix resin comprising one or more acidic functional groups;
a second additive resin that is different from and substantially immiscible with the first resin, the second resin comprising as polymerized units a monomer of the formula (I):
wherein R 1 is hydrogen or a C1 to C6 optionally substituted alkyl or fluoroalkyl group, R 2 is an optionally substituted cycloalkyl or branched alkyl group, R 3 is an optionally substituted alkylene group and R 4 and R 5 are independently C1 to C4 fluoroalkyl groups;
wherein the second resin has a lower surface energy than a surface energy of the first resin; and
a mixture of solvents effective to achieve phase separation of the additive resin from other resin(s) in the composition during spin-coating; and
(c) exposing the photoresist layer to actinic radiation.
10. The method of claim 9 , wherein R 2 is an optionally substituted C3 to C6 isoalkyl group.
11. The method of claim 9 , wherein the step c) of exposing the photoresist layer to actinic radiation is an immersion lithography process with water as the immersion fluid, and provides a receding contact angle of greater than 72°.
12. The method of claim 9 , wherein the mixture of solvents comprises a dialkyl glycol monoalkyl ether.
13. The method of claim 9 , wherein the second resin further comprises as polymerized units a second monomer comprising one or more acid-labile groups.
14. The method of claim 9 , wherein the mixture of solvents comprises: a primary solvent and an additive solvent having a boiling point higher than that of the primary solvent, wherein the primary solvent has a boiling point of from 120 to 140° C. and the additive solvent has a boiling point of from 170 to 200° C.
15. The method of claim 14 , wherein the additive solvent is present in an amount of from 3 to 15 wt % based on the mixture of solvents.
16. A method of processing a photoresist composition, comprising:
(a) applying a photoresist composition over a substrate to form a photoresist layer;
(b) applying over the photoresist layer a topcoat composition, the composition comprising:
a first matrix resin comprising one or more acidic functional groups;
a second additive resin that is different from the first resin, the second resin comprising as polymerized units a monomer of the formula (I):
wherein R 1 is hydrogen or a C1 to C6 optionally substituted alkyl or fluoroalkyl group, R 2 is an optionally substituted cycloalkyl or branched alkyl group, R 3 is an optionally substituted alkylene group and R 4 and R 5 are independently C1 to C4 fluoroalkyl groups;
wherein the second resin has a lower surface energy than a surface energy of the first resin; and
a mixture of solvents effective to achieve phase separation of the additive resin from other resin(s) in the composition during spin-coating, wherein the mixture of solvents comprises: a primary solvent and an additive solvent having a boiling point higher than that of the primary solvent, wherein the primary solvent has a boiling point of from 120 to 140° C. and the additive solvent has a boiling point of from 170 to 200° C.; and
(c) exposing the photoresist layer to actinic radiation;
wherein the mixture of solvents comprises: a dialkyl glycol monoalkyl ether; an alcohol; and an alkyl ether or an alkane.