Aromatic resins for underlayers

Abstract

Polymeric reaction products of certain aromatic alcohols with certain diaryl-substituted aliphatic alcohols are useful as underlayers in semiconductor manufacturing processes.

Claims

1. A polymeric reaction product of one or more first monomers of the formula (1) ##STR00023## wherein Ar.sup.1 and Ar.sup.2 independently represent an aromatic moiety having from 2 to 7 fused aromatic rings; R.sup.1 and R.sup.2 are independently selected from (C.sub.1-C.sub.20)alkyl, (C.sub.2-C.sub.20)alkenyl, (C.sub.2-C.sub.20)alkynyl, (C.sub.6-C.sub.30)aryl, (C.sub.7-C.sub.30)aralkyl and (C.sub.7-C.sub.30)alkaryl; X.sup.1 is selected from OH, SH and OR.sup.3; R.sup.3 is (C.sub.1-C.sub.20)alkyl; and each of n1 and n2 is an integer independently selected from 0 to 5; wherein R.sup.1 and R.sup.2 may be taken together to form a 5- to 7-membered fused ring; one or more second monomers of the formula (2) ##STR00024## wherein Ar.sup.3 and Ar.sup.4 independently represent an aromatic; R.sup.4 is selected from hydroxy, (C.sub.1-C.sub.20)alkyl, (C.sub.1-C.sub.20)alkoxy, (C.sub.2-C.sub.20)alkenyl, (C.sub.2-C.sub.20)alkynyl, mercapto, (C.sub.1-C.sub.20)alkylthio, (C.sub.6-C.sub.30)aryl, (C.sub.7-C.sub.30)aralkyl and (C.sub.7-C.sub.30)alkaryl; R.sup.5 is selected from (C.sub.1-C.sub.20)alkyl, (C.sub.2-C.sub.20)alkenyl, (C.sub.2-C.sub.20)alkynyl, (C.sub.6-C.sub.30)aryl, (C.sub.7-C.sub.30)aralkyl and (C.sub.7-C.sub.30)alkaryl; X.sup.2 is selected from OH, SH and OR.sup.6; R.sup.6 is (C.sub.1-C.sub.20)alkyl; n3 is an integer from 0 to 4; and n4 is an integer from 0 to 5; wherein R.sup.4 and R.sup.5 may be taken together to form a 5- to 7-membered fused ring; and optionally one or more third monomers of formula (3) ##STR00025## wherein R.sup.7 is selected from hydroxy, (C.sub.1-C.sub.20)alkyl, (C.sub.1-C.sub.20)alkoxy, (C.sub.2-C.sub.20)alkenyl, (C.sub.2-C.sub.20)alkynyl, mercapto, (C.sub.1-C.sub.20)alkylthio, (C.sub.6-C.sub.30)aryl, (C.sub.7-C.sub.30)aralkyl and (C.sub.7-C.sub.30)alkaryl; R.sup.8 is selected from (C.sub.1-C.sub.20)alkyl, (C.sub.2-C.sub.20)alkenyl, (C.sub.2-C.sub.20)alkynyl, and (C.sub.7-C.sub.30)aralkyl; X.sup.3 is selected from OH, SH and OR.sup.9; R.sup.9 is (C.sub.1-C.sub.20)alkyl; and Ar.sup.5 is an aromatic moiety.

2. The polymeric reaction product of claim 1 wherein Ar.sup.1 is the same as Ar.sup.2.

3. The polymeric reaction product of claim 1 wherein Ar.sup.3 is different from Ar.sup.4.

4. The polymeric reaction product of claim 3 wherein Ar.sup.3 represents an aryl moiety having from 3 to 7 fused aromatic rings and Ar.sup.4 represents an aryl moiety having from 2 to 4 fused aromatic rings.

5. The polymeric reaction product of claim 1 wherein at least one of Ar.sup.3 and Ar.sup.4 represents an aryl moiety having at least 4 fused aromatic rings.

6. The polymeric reaction product of claim 1 wherein each of n1 and n2 is independently selected from 0 to 2.

7. A method of making the polymeric reaction product of claim 1 comprising reacting the one or more first monomers with the one or more second monomers in the presence of an acid catalyst in an organic solvent.

8. A composition comprising the polymeric reaction product of claim 1, organic solvent, and optionally one or more additives chosen from curing agents, crosslinking agents, and surfactants.

9. A process of forming a patterned layer comprising disposing a layer of the composition of claim 8 on a substrate; removing organic solvent to form a polymeric reaction product layer; disposing a layer of a photoresist on the polymeric reaction product layer; exposing the photoresist layer to actinic radiation through a mask; developing the exposed photoresist layer to form a resist pattern; and transferring the pattern to the polymeric reaction product layer to expose portions of the substrate.

10. The process of claim 9 further comprising the steps of patterning the substrate; and then removing the patterned polymeric reaction product layer.

11. The process of claim 9 further comprising the steps of disposing a conformal silicon-containing layer over the patterned polymeric reaction product layer and exposed portions of the substrate; partially etching the silicon-containing layer to expose a top surface of the patterned polymeric reaction product layer and a portion of the substrate.

Description

EXAMPLE 1

(1) First monomer (1e) (0.3 g, 0.0011 mol), second monomer (2a) (4.0 g, 0.011 mol), pTSA (0.09 g, 0.0005 mol), and 18 mL of PGME were added to a three-necked round bottom flask equipped with a magnetic stir bar and condenser. The mixture was then stirred for 8 hours at 90 C. The reaction mixture was then cooled to room temperature and the aromatic resin reaction product (Sample 1) was precipitated with a mixture of methanol (230 mL) and DI water (18 mL). The precipitate was filtered and dried in a vacuum oven.

(2) ##STR00015##

(3) The reaction product (Sample 1) was analyzed by GPC and found to have an M.sub.w of 2505, a number average molecular weight (M.sub.n) of 1787, and a polydispersity of 1.40.

COMPARATIVE EXAMPLE 1

(4) A sample (Comparative 1) of a polymer having the repeating unit shown in formula (6) was obtained from Gun Ei Chemical, and was used as is. The molecular weight of this sample was: M.sub.w=6066, and M.sub.n=2362.

(5) ##STR00016##

COMPARATIVE EXAMPLE 2

(6) Monomer (2a) (4.40 g, 0.0118 mol), pTSA (0.1 g, 0.0006 mol), and PGME (18 mL) were added to a three-necked round bottom flask equipped with a magnetic stir bar, condenser. The mixture was then stirred for 7 hours at 90 C. The reaction mixture was then cooled to room temperature and the aromatic resin reaction product (Comparative 2) was precipitated with a mixture of methanol (252 mL) and DI water (20 mL). The precipitate (Comparative 2) was filtered and dried in a vacuum oven. Comparative 2 was analyzed by GPC and found to have an M.sub.w of 2726, a number average molecular weight (M.sub.n) of 1920, and a polydispersity of 1.42.

(7) ##STR00017##

EXAMPLE 2

(8) The procedure of Example 1 is repeated except that the following first monomer (2f) and second monomer (2b) are used in the same relative molar amounts, with pTSA as the acid catalyst, to prepare Sample 2.

(9) ##STR00018##

EXAMPLE 3

(10) The procedure of Example 1 is repeated except that the following first monomer (1e) and second monomer (2b) are used in the same relative molar amounts, with pTSA as the acid catalyst, to prepare Sample 3.

(11) ##STR00019##

EXAMPLE 4

(12) The procedure of Example 1 is repeated except that the following first monomer (1f) and second monomer (2a) are used in the same relative molar amounts, with pTSA as the acid catalyst, to prepare Sample 4.

(13) ##STR00020##

EXAMPLE 5

(14) The procedure of Example 1 is repeated except that the following first monomer (1a) is used to prepare Sample 5.

(15) ##STR00021##

EXAMPLE 5

(16) The procedure of Example 1 is repeated except that the following first monomer (1d) is used to prepare Sample 6.

(17) ##STR00022##

EXAMPLE 6

(18) The procedure of Example 1 is repeated except that the first and second monomers are replaced with those reported in Tables 1 and 2, to produce the Samples in Table 3.

(19) TABLE-US-00001 TABLE 1 First Monomer Ar.sup.1 Ar.sup.2 R.sup.1 R.sup.2 n1 n2 X.sup.1 1g Benzene Naphthalene 0 0 OH 1h Benzene Phenanthrene 0 0 OH 1i Benzene Benzene 0 0 OH 1j Pyrene Pyrene 0 0 OH 1k Pyrene Anthracene 0 0 OCH.sub.3 1l Pyrene Naphthalene Phenyl 1 0 OH 1m Coronene Naphthalene 0 0 OH 1n Pyrene Benzene Phenyl 1 0 OH

(20) TABLE-US-00002 TABLE 2 Second Mono- mer Ar.sup.3 Ar.sup.4 R.sup.4 R.sup.5 n3 n4 X.sup.2 2c Benzene Phenanthrene 0 0 OH 2d Naphthalene Naphthalene OH 1 0 OH 2e Pyrene Pyrene 0 0 OH 2f Pyrene Pyrene OH 1 0 OH 2g Anthracene Pyrene 0 0 OH 2h Pyrene Naphthalene Phenyl 1 0 OH 2i Naphthalene Perylene 0 0 OH 2j Anthracene Benzene Phenyl 1 0 OH 2k Naphthalene Pyrene Phenyl 0 1 OH 2l Pyrene Naphthalene Biphenyl 0 1 OH

EXAMPLE 7

(21) The procedure of Example 6 is repeated to prepare the Samples listed in Table 3.

(22) TABLE-US-00003 TABLE 3 First Monomer Second Monomer Sample 1f 2h 7 1a 2l 8 1c 2e 9 1j 2c 10 1j 2e 11 1n 2l 12 1b 2b 13 1e 2i 14 1e 2l 15 1j 2h 16

EXAMPLE 8

(23) The aromatic resin reaction products listed in Table 5 were individually formulated in propyleneglycol monomethylether acetate (PGMEA) or cyclohexanone at 10 wt % solids, filtered through 0.2 m poly(tetrafluoroethylene) (PTFE) syringe filter, coated on a silicon wafer at 1500 rpm and baked at 100 C. for 60 seconds to remove the solvent, and further cured at 400 C. for 60 seconds. The cured films were etched using either O.sub.2 or CF.sub.4 plasma using a Plasmatherm RIE790 tool (from Plasma-Therm Co.) and the conditions shown in Table 4. The etching data, in /sec., are reported in Table 5.

(24) TABLE-US-00004 TABLE 4 Gas O.sub.2 CF.sub.4 Flow (sccm) 60 50 Power (W) 700 500 Pressure (mTorr) 10 10 Etch time (sec.) 30 60

(25) TABLE-US-00005 TABLE 5 Sample O.sub.2 Etch - /sec. CF.sub.4 Etch - /sec. 1 24.2 4.7 Comparative 1 32.0 5.0 Comparative 2 27.4 3.5