AROMATIC UNDERLAYER

Abstract

Curable homopolymers formed from monomers having two 2-naphthol moieties are useful as underlayers in semiconductor manufacturing processes.

Claims

1. A method comprising: (a) providing an electronic device substrate; (b) coating a layer of a coating composition comprising one or more curable compounds on a surface of the electronic device substrate, wherein the one or more curable compounds is a polymer comprising repeating units of formula (1) ##STR00020## wherein Z is a covalent chemical bond or a divalent linking group chosen from O, C(O), S, S(O), S(O).sub.2, N(R), C.sub.1-100-hydrocarbylene, substituted C.sub.1-100-hydrocarbylene, O(C.sub.1-20-alkylene-O).sub.m1, O(C.sub.5-60-arylene-O).sub.m2, and C(R.sup.3)(R.sup.4); R is chosen from H, C.sub.1-20-alkyl, C.sub.5-30-aryl, and C.sub.2-20-unsaturated aliphatic moiety; each R.sup.1 and each R.sup.2 are independently chosen from H, OR, C.sub.1-30-hydrocarbyl, substituted C.sub.1-30-hydrocarbyl, C(O)OR.sup.5, SR, S(O)R, S(O).sub.2R, N(R.sup.5)(R.sup.6), and N(R7)C(O)R.sup.5; one R.sup.1 and one R.sup.2 and Z may be taken together along with the atoms to which they are attached to form a 5 to 6-membered ring; R.sup.3 and R.sup.4 are independently chosen from C.sub.1-20-alkyl and C.sub.5-30-aryl; R.sup.3 and R.sup.4 may be taken together with the carbon to which they are attached to form a 5- or 6-membered ring which may be fused to one or more aromatic rings, and which 5- or 6-membered ring is optionally substituted; R.sup.5 and R.sup.6 are independently C.sub.1-20-alkyl or C.sub.5-30-aryl; R.sup.7 is H or R.sup.6; R.sup.5 and R.sup.6 may be taken together along with the atoms to which they are attached to form a 5- to 6-membered ring; each of a1 and a2 is from 0 to 5; each of m1 and m2=1 to 100; and n=2 to 1000; (c) curing the layer of the curable compound to form an underlayer; (d) coating a layer of a photoresist on the underlayer; (e) exposing the photoresist layer to actinic radiation through a mask; (f) developing the exposed photoresist layer to form a resist pattern; and (g) transferring the pattern to the underlayer to expose portions of the electronic device substrate.

2. The method of claim 1 further comprising the steps of patterning the substrate; and then removing the patterned underlayer.

3. The method of claim 1 further comprising the step of coating one or more of a silicon-containing layer, an organic antireflective coating layer and a combination thereof over the underlayer before step (d).

4. The method of claim 3 further comprising the step of transferring the pattern to the one or more of the silicon-containing layer, the organic antireflective coating layer and the combination thereof after step (f) and before step (g).

5. The method of claim 1 wherein the coating composition further comprises one or more of an organic solvent a curing agent, and a surface leveling agent.

6. The method of claim 1 wherein the repeating units of formula (1) are chosen from formulae: ##STR00021## ##STR00022##

7. An electronic device comprising an electronic device substrate having a layer of a polymer comprising as polymerized units one or more curable compounds on a surface of the electronic device substrate, wherein the one or more curable compounds is a polymer comprising repeating units of formula (1) ##STR00023## wherein Z is a covalent chemical bond or a divalent linking group chosen from O, C(O), S, S(O), S(O).sub.2, N(R), C.sub.1-100-hydrocarbylene, substituted C.sub.1-100-hydrocarbylene, O(C.sub.1-20-alkylene-O).sub.m1, O(C.sub.5-60-arylene-O).sub.m2, and C(R.sup.3)(R.sup.4); R is chosen from H, C.sub.1-20-alkyl, C.sub.5-30-aryl, and C.sub.2-20-unsaturated aliphatic moiety; each R.sup.1 and each R.sup.2 are independently chosen from H, OR, C.sub.1-30-hydrocarbyl, substituted C.sub.1-30-hydrocarbyl, C(O)OR.sup.5, SR, S(O)R, S(O).sub.2R, N(R.sup.5)(R.sup.6), and N(R7)C(O)R.sup.5; one R.sup.1 and one R.sup.2 and Z may be taken together along with the atoms to which they are attached to form a 5 to 6-membered ring; R.sup.3 and R.sup.4 are independently chosen from C.sub.1-20-alkyl and C.sub.1-30-aryl; R.sup.3 and R.sup.4 may be taken together with the carbon to which they are attached to form a 5- or 6-membered ring which may be fused to one or more aromatic rings, and which 5- or 6-membered ring is optionally substituted; R.sup.5 and R.sup.6 are independently C.sub.1-20-alkyl or C.sub.5-30-aryl; R.sup.7 is H or R.sup.6; R.sup.5 and R.sup.6 may be taken together along with the atoms to which they are attached to form a 5- to 6-membered ring; each of a1 and a2 is from 0 to 5; each of m1 and m2=1 to 100; and n=2 to 1000.

8. A polymer comprising repeating units of formula (1) ##STR00024## wherein Z is a covalent chemical bond or a divalent linking group chosen from O, C(O), S, S(O), S(O).sub.2, N(R), C.sub.1-100-hydrocarbylene, substituted C.sub.1-100-hydrocarbylene, O(C.sub.1-20-alkylene-O).sub.m1, O(C.sub.5-60-arylene-O).sub.m2, and C(R.sup.3)(R.sup.4); R is chosen from H, C.sub.1-20-alkyl, C.sub.5-30-aryl, and C.sub.2-20-unsaturated aliphatic moiety; each R.sup.1 and each R.sup.2 are independently chosen from H, OR, C.sub.1-30-hydrocarbyl, substituted C.sub.1-30-hydrocarbyl, C(O)OR.sup.5, SR, S(O)R, S(O).sub.2R, N(R.sup.5)(R.sup.6), and N(R7)C(O)R.sup.5; one R.sup.1 and one R.sup.2 and Z may be taken together along with the atoms to which they are attached to form a 5 to 6-membered ring; R.sup.3 and R.sup.4 are independently chosen from C.sub.1-20-alkyl and C.sub.5-30-aryl; R.sup.3 and R.sup.4 may be taken together with the carbon to which they are attached to form a 5- or 6-membered ring which may be fused to one or more aromatic rings, and which 5- or 6-membered ring is optionally substituted; R.sup.5 and R.sup.6 are independently C.sub.1-20-alkyl or C.sub.5-30-aryl; R.sup.7 is H or R.sup.6; R.sup.5 and R.sup.6 may be taken together along with the atoms to which they are attached to form a 5- to 6-membered ring; each of a1 and a2 is from 0 to 5; each of m1 and m2=1 to 100; and n=2 to 1000.

Description

EXAMPLE 1

[0035] Monomer M-1 (4.66 g, 10 mmol) was dissolved in 41.71 g of ethyl lactate. To this solution was added 0.23 g (0.5 mmol) of di--hydroxo-bis-[(N,N,N,N-tetramethylethylene-diamine)copper(II)] chloride (Cu-TMEDA), and the reaction mixture was stirred in air at room temperature for 24 hours. The mixture was slowly added to a mixture of methanol containing 1 M hydrochloric acid (200 mL, v/v=20/80). The precipitated product was collected by filtration, and then re-dissolved in ethyl acetate. The solution was then slowly added to methanol, and the precipitated product was collected, and dried at 65 C. under vacuum for 2 days. Polymer P-1A (3.2 g) was obtained in 69% yield. GPC: M.sub.w=1.9 K, PDI=1.4. This reaction is shown in Reaction Scheme 1.

EXAMPLE 2

[0036] The procedure of Example 1 was repeated as follows. Monomer M-1 (4.66 g, 10 mmol) was dissolved in 43.80 g of ethyl lactate. To this solution was added 0.46 g (1.0 mmol) of Cu-TMEDA, and the reaction mixture was stirred in air at room temperature for 24 hours. The mixture was slowly added to a mixture of methanol containing 1 M hydrochloric acid (200 mL, v/v=20/80). The precipitated product was collected by filtration, and then re-dissolved in ethyl acetate. The solution was then slowly added to methanol, and the precipitated product was collected, and dried at 65 C. under vacuum for 2 days. Polymer P-1B (3.61 g) was obtained in 78% yield. GPC: M.sub.w=3.6 K, PDI=1.5. This reaction is shown in Reaction Scheme 1.

##STR00016##

EXAMPLE 3

[0037] Monomer M-2 (4.51 g, 10 mmol) was dissolved in 44.73 g of ethyl lactate. To this solution was added 0.46 g (1.0 mmol) of Cu-TMEDA, and the reaction mixture was stirred in the open air at room temperature for 24 hours. The mixture was slowly added to a mixture of methanol containing 1 M hydrochloric acid (200 mL, v/v=20/80). The precipitated product was collected by filtration, and then re-dissolved in ethyl acetate. The solution was then slowly added to methanol, the precipitated product was collected, and dried at 65 C. under vacuum for 2 days to yield Polymer P-2 (3.79 g) in 84% yield. GPC: M.sub.w=2.2 K, PDI=1.6. This reaction is shown in Reaction Scheme 2.

##STR00017##

EXAMPLE 4

[0038] Monomer M-3 (3.94 g, 10 mmol) was dissolved in 17.64 g of ethyl lactate. To this solution was added 0.46 g (1.0 mmol) of Cu-TMEDA, and the reaction mixture was stirred in air at room temperature for 24 hours. The mixture was slowly added to a mixture of methanol containing 1 M hydrochloric acid (200 mL, v/v=20/80). The precipitated product was collected by filtration, and then re-dissolved in ethyl acetate. The solution was then slowly added to methanol, the precipitated product was collected, and dried at 65 C. under vacuum for 2 days to provide 3.10 g of Polymer P-3 in 79% yield. GPC: M.sub.w=195 K, PDI=19. This reaction is shown in Reaction Scheme 3.

##STR00018##

EXAMPLE 5

[0039] Monomer M-4 (6.35 g, 10 mmol) was dissolved in 27.25 g of ethyl lactate. To this solution was added 0.46 g (1.0 mmol) of Cu-TMEDA, and the reaction mixture was stirred in air at room temperature for 24 hours. The mixture was slowly added to a mixture of methanol containing 1 M hydrochloric acid (200 mL, v/v=20/80). The precipitated product was collected by filtration, and then re-dissolved in ethyl acetate. The solution was then slowly added to methanol, the precipitated product was collected, and dried at 65 C. under vacuum for 2 days to give 5.31 g of Polymer P-4 in 83% yield. GPC: M.sub.w=3.0 K. PDI=1.5. This reaction is shown in Reaction Scheme 4.

##STR00019##

EXAMPLE 6: SOLUBILITY

[0040] Solubility was evaluated by mixing a compound of the invention with each of PGME and PGMEA at 5% solids. Those mixtures were visibly inspected as well as checked using a turbidity meter (Orbeco-Hellige Co). If the turbidity value was less than 1, the compound was rated soluble (S) and if the turbidity value was greater than 1, it was rated not soluble (NS). The results are reported in Table 1. As can be seen from these data, the compounds of the invention are all soluble in each of PGME and PGMEA.

TABLE-US-00001 TABLE 1 Solubility (5% solids) Entry No. Polymer PGMEA PGME 1 P-1A S S 2 P-1B S S 3 P-2 S S 4 P-3 S S 5 P-4 S S

EXAMPLE 7: THERMAL STABILITY

[0041] Thermal stability of compounds of the invention was evaluated using a Thermal Gravimetric Analyzer (TGA) Q500 from TA-Instrument, under the following conditions: under N.sub.2, ramp at 10 C./min. to 700 C.; and under air, ramp at 10 C./min. to 700 C. The temperature at which the materials lost 5% of their weight (Td.sub.5%) are reported in Table 2.

TABLE-US-00002 TABLE 2 Td.sub.5% ( C.) Entry No. Polymer Under N.sub.2 Under Air 1 P-1A 465 380 2 P-1B 467 367 3 P-2 442 412 4 P-3 427 414 5 P-4 446 454

EXAMPLE 8

[0042] Solvent strip resistance was measured as an indication of film crosslinking. Compositions of compounds of the invention were prepared in PGMEA at 4.5% solids. Each composition was spin-coated on an 8 (200 mm) silicon wafer at a rate of 1500 rpm using an ACT-8 Clean Track (Tokyo Electron Co.), and then baked at 350 C. for 60 seconds to form a film. Initial film thickness was measured using an OptiProbe from Therma-Wave Co. Next, a commercial remover, PGMEA was applied to each of the films for 90 seconds followed by a post strip baking step at 105 C. for 60 seconds. The thickness of each film following post strip baking was again measured to determine the amount of film thickness lost. The difference in film thickness before and after contact with the remover is reported in Table 3 as the percentage of film thickness remaining. As can be seen from the data, films formed from polymer P-3 and P-4 of the invention retained greater than 99% of their thickness after contact with the remover.

TABLE-US-00003 TABLE 3 Entry No. Polymer % Film Remaining 1 P-1A 32.8 2 P-1B 39.7 3 P-2 4.7 4 P-3 >99 5 P-4 >99

EXAMPLE 9

[0043] Polymers of the invention were evaluated to determine their gap-filling properties. Gap fill templates were created at CNSE Nano-FAB (Albany, N.Y.). The template had SiO.sub.2 film thickness of 100 nm, and various pitch and patterns. The template coupons were baked at 150 C. for 60 seconds as a dehydration bake prior to coating the coupons with the present compositions. Each coating composition (4.5% solids in PGMEA) was coated on a template coupon using an ACT-8 Clean Track (Tokyo Electron Co.) spin coater and a spin rate of 1500 rpm+/200 rpm. The target film thickness was 100 nm after curing, and the composition dilution was adjusted accordingly to give approximately the target film thickness after curing. The films were cured by placing the wafer on a hot plate at 350 C. for 60 sec. Cross-section scanning electron microscope (SEM) images of the coated coupons were collected using an Hitachi S4800 SEM (from Hitachi High Technologies). Planarization quality of the films was obtained from the SEM images using Hitachi offline CD measurement software or CDM software by measuring the difference in thickness of the film (FT) over vias from the film thickness over trenches. Films having a FT<20 nm were considered to have Good planarization and films having a FT>20 nm were considered to have Poor planarization. Gap filling was evaluated by visually inspecting the SEM images to see if there were any voids or bubbles in the trench patterns. Films having no voids in the trench patterns were considered to have Good gap fill and films having voids in the trench patters were considered to have Poor gap fill. These results are reported in Table 4.

TABLE-US-00004 TABLE 4 Sample No. Polymer Planarization Gap Fill 1 P-1A Poor Poor 2 P-1B Poor Poor 3 P-2 Poor Poor 4 P-3 Good Good 5 P-4 Good Good