Photolithographic methods
View Patent ↗Provided are photoresist overcoat compositions, substrates coated with the overcoat compositions and methods of forming electronic devices by a negative tone development process. The compositions, coated substrates and methods find particular applicability in the manufacture of semiconductor devices.
1. A method of forming an electronic device, comprising:
(a) providing a semiconductor substrate comprising one or more layers to be patterned;
(b) forming a photoresist layer over the one or more layers to be patterned;
(c) coating a photoresist overcoat composition over the photoresist layer, wherein the overcoat composition comprises a basic quencher, a polymer and an organic solvent;
(d) baking the photoresist overcoat composition to form a layer having a water receding contact angle of from 70 to 85°;
(e) exposing the photoresist layer to actinic radiation; and
(f) developing the exposed photoresist layer with an organic solvent developer.
2. The method of claim 1 , wherein the layer of the photoresist overcoat composition has a water receding contact angle of from 75 to 85°.
3. The method of claim 1 , wherein the photoresist layer exposure is conducted by immersion lithography.
4. The method of claim 1 , wherein the polymer comprises as polymerized units a monomer of the following general formula (I):
wherein: R 1 is chosen from hydrogen and substituted or unsubstituted C1 to C3 alkyl, R 2 is chosen from substituted and unsubstituted C1 to C15 alkyl; X is oxygen, sulfur or is represented by the formula NR 3 , wherein R 3 is chosen from hydrogen and substituted and unsubstituted C1 to C10 alkyl; and Z is a single bond or a spacer unit chosen from substituted and unsubstituted aliphatic and aromatic hydrocarbons, and combinations thereof, optionally with one or more linking moiety chosen from —O—, —S—, —COO— and —CONR 4 — wherein R 4 is chosen from hydrogen and substituted and unsubstituted C1 to C10 alkyl.
5. The method of claim 1 , wherein the polymer contains as polymerized units a monomer of the following general formula (II):
wherein R 5 , R 6 , and R 7 independently represent hydrogen or a C 1 to C 3 alkyl, fluoroalkyl or fluoroalcohol group.
6. The method of claim 5 , wherein Z is a single bond.
7. The method of claim 4 , wherein the overcoat composition comprises a plurality of polymers.
8. The method of claim 7 , wherein the overcoat composition comprises a second polymer comprising as polymerized units a monomer of the general formula (I).
9. The method of claim 1 , wherein the polymer is free of silicon and fluorine.
10. The method of claim 1 , wherein the overcoat composition is free of acid generator compounds.
11. The method of claim 1 , wherein the basic quencher is present at an interface between the overcoat coating and photoresist layer.
12. A method of forming an electronic device, comprising:
(a) providing a semiconductor substrate comprising one or more layers to be patterned;
(b) forming a photoresist layer over the one or more layers to be patterned;
(c) coating a photoresist overcoat composition over the photoresist layer, wherein the overcoat composition comprises a basic quencher, a plurality of polymers and an organic solvent;
(d) exposing the photoresist layer to actinic radiation; and
(e) developing the exposed photoresist layer with an organic solvent developer.
13. The method of claim 12 , wherein the photoresist layer exposure is conducted by immersion lithography.
14. The method of claim 12 , wherein the overcoat composition comprises a polymer comprising as polymerized units a monomer of the following general formula (I):
wherein: R 1 is chosen from hydrogen and substituted or unsubstituted C1 to C3 alkyl, R 2 is chosen from substituted and unsubstituted C1 to C15 alkyl; X is oxygen, sulfur or is represented by the formula NR 3 , wherein R 3 is chosen from hydrogen and substituted and unsubstituted C1 to C10 alkyl; and Z is a single bond or a spacer unit chosen from substituted and unsubstituted aliphatic and aromatic hydrocarbons, and combinations thereof, optionally with one or more linking moiety chosen from —O—, —S—, —COO— and —CONR 4 — wherein R 4 is chosen from hydrogen and substituted and unsubstituted C1 to C10 alkyl.
15. The method of claim 12 , wherein the overcoat composition comprises a polymer comprising a polymer comprising as polymerized units a monomer of the following general formula (II):
wherein R 5 , R 6 , and R 7 independently represent hydrogen or a C 1 to C 3 alkyl, fluoroalkyl or fluoroalcohol group.
16. The method of claim 15 , wherein Z is a single bond.
17. The method of claim 12 , wherein the overcoat composition is free of acid generator compounds.
18. The method of claim 12 , wherein the basic quencher is present at an interface between the overcoat coating and photoresist layer.