PHOTORESIST UNDERLAYER COMPOSITIONS AND PATTERNING METHODS

1 . A method of forming a pattern on a substrate, the method comprising:

forming a photoresist underlayer over a surface of the substrate, wherein the photoresist underlayer is formed from a composition comprising a polymer having a glass transition temperature of less than 110° C. and a solvent;

subjecting the photoresist underlayer to a metal precursor, wherein the metal precursor infiltrates a free volume of the photoresist underlayer; and

exposing the metal precursor-treated photoresist underlayer to an oxidizing agent to provide a metallized photoresist underlayer.

2 . The method of claim 1 , wherein prior to the subjecting of the photoresist underlayer to the metal precursor, the method further comprises:

forming an antireflective coating layer over the photoresist underlayer and a photoresist layer over the antireflective coating layer;

exposing the photoresist layer to activating radiation and developing the exposed photoresist layer to form a photoresist pattern; and

transferring the photoresist pattern by etching to the antireflective coating layer and the photoresist underlayer.

3 . The method of claim 1 , wherein the metal precursor comprises a metal chosen from aluminum, tin, tungsten, titanium, molybdenum, hafnium, or a combination thereof.

4 . The method of claim 1 , wherein the polymer has a glass transition temperature of greater than 0° C. and less than 100° C.

5 . The method of claim 1 , wherein the polymer comprises a functional group selected from a keto-carbonyl, an ester, a hydroxy, acetal, ketal, carboxylic acid, amide, carbamate, urea, carbonate, aldehyde, imide, sulfonic acid, sulfonate ester, or a combination thereof.

6 . The method of claim 1 , wherein the polymer comprises polymerized units of monomer units chosen from acrylates, methacrylates, acrylamides, methacrylamides, vinyl ethers, vinyl aromatics, or a combination thereof.

7 . The method of claim 1 , wherein the polymer comprises a monomer unit of Formula (1)

wherein in Formula (1),

D is absent, —O—, —(CHR a ) n —, —(CHR a CHR b O) m —, optionally substituted C 6-14 arylene, optionally substituted C 3-18 heteroarylene, optionally substituted C 5-12 cycloalkylene, or a combination thereof, wherein each R a and each R b is independently hydrogen, or substituted or unsubstituted C 1-6 alkyl, and n is an integer of 1 to 12, and m is an integer of 1 to 8;

E is absent, —O—, —NR N —, or E can join with D to from a ring;

R 1 and R N are independently hydrogen, or substituted or unsubstituted C 1-6 alkyl; and

R 2 is hydrogen, substituted or unsubstituted C 1-16 alkyl, substituted or unsubstituted C 1-16 heteroalkyl, substituted or unsubstituted C 5-20 cycloalkyl, substituted or unsubstituted C 3-20 heterocycloalkyl, substituted or unsubstituted C 2-16 alkenyl, substituted or unsubstituted C 2-16 alkynyl, substituted or unsubstituted C 6-18 aryl, substituted or unsubstituted C 7-30 arylalkyl, substituted or unsubstituted C 7-30 alkylaryl, substituted or unsubstituted C 3-18 heteroaryl, substituted or unsubstituted C 4-30 heteroarylalkyl, or R 2 can join with D to form a ring.

8 . The method of claim 7 , wherein D is absent, —O—, —(CHR a ) n —, optionally substituted C 6-14 arylene, or a combination thereof; E is absent or —O—; and R 2 is hydrogen, substituted or unsubstituted C 1-10 alkyl, substituted or unsubstituted C 1-10 heteroalkyl with a total of one to four ether, ester, amide, or —C(O)— groups, unsubstituted C 6-14 aryl, C 6-14 aryl substituted with —OR 3 , —C(O)OR 3 , —C(O)N(R N )R 3 , or —C(O)R 3 , unsubstituted C 3-12 heteroaryl, or C 3-12 heteroaryl substituted with —OR 3 , —C(O)OR 3 , —C(O)N(R N )R 3 , or —C(O)R 3 , wherein R 3 is H, or substituted or unsubstituted C 1-6 alkyl.

9 . The method of claim 1 , wherein the polymer comprises a monomer unit of Formula (2)

wherein in Formula (2),

G is absent, —(CHR a ) n —, —(CHR a CHR b O) m —, —O—, —C(O)O—, —C(O)OR 5 —, —C(O)—, —C(O)N(R N )—, optionally substituted C 6-14 arylene, optionally substituted C 3-13 heteroarylene, or optionally substituted C 5 -C 12 cycloalkylene, wherein R 1 , R N , each R a and each R b , is independently hydrogen, optionally substituted C 1-6 alkyl, an optionally substituted C 6-14 aryl, or an optionally substituted C 3-13 heteroaryl; and n is an integer of 1 to 12, and m is an integer of 1 to 8;

R 4 is hydrogen, optionally substituted C 1-10 alkyl, optionally substituted C 1-10 heteroalkyl with a total of one to four ether, ester, amide, or —C(O)— groups, optionally substituted C 2-10 alkenyl, optionally substituted C 2-10 alkynyl, optionally substituted C 6-14 aryl, or optionally substituted C 3-12 heteroaryl, and

R 5 is an optionally substituted C 1-4 alkylene or C 2-4 alkenylene.

10 . The method of claim 1 , further comprising curing the photoresist underlayer to crosslink the polymer prior to the subjecting of the photoresist underlayer to the metal precursor.