Application of a supercritical CO2 system for curing low k dielectric materials
First Claim
1. A method of curing and modifying a low k dielectric layer on a substrate, comprising:
- providing a substrate;
coating a spin-on low k dielectric layer on said substrate;
positioning said substrate in a process chamber; and
treating said substrate with a supercritical fluid (SCF) comprised of CO2 and a co-solvent which is H2O2, CF3—
X, or Y—
F wherein X=NR1R2, —
OR3, —
O2CR3, —
(C═
O)R3, or R3 and wherein Y=H or an alkyl group and R1, R2, R3=H or an alkyl group, at least until an endpoint is reached.
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Accused Products
Abstract
A method and apparatus for curing and modifying a low k dielectric layer in an interconnect structure is disclosed. A spin-on low k dielectric layer which includes an organic silsesquioxane, polyarylether, bisbenzocyclobuene, or SiLK is spin coated on a substrate. The substrate is placed in a process chamber in a supercritical CO2 system and is treated at a temperature between 30° C. and 150° C. and at a pressure from 70 to 700 atmospheres. A co-solvent such as CF3—X or F—X is added that selectively replaces C—CH3 bonds with C—CF3 or C—F bonds. Alternatively, H2O2 is employed as co-solvent to replace a halogen in a C—Z bond where Z=F, Cl, or Br with an hydroxyl group. Two co-solvents may be combined with CO2 for more flexibility. The cured dielectric layer has improved properties that include better adhesion, lower k value, increased hardness, and a higher elastic modulus.
20 Citations
78 Claims
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1. A method of curing and modifying a low k dielectric layer on a substrate, comprising:
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providing a substrate;
coating a spin-on low k dielectric layer on said substrate;
positioning said substrate in a process chamber; and
treating said substrate with a supercritical fluid (SCF) comprised of CO2 and a co-solvent which is H2O2, CF3—
X, or Y—
F wherein X=NR1R2, —
OR3, —
O2CR3, —
(C═
O)R3, or R3 and wherein Y=H or an alkyl group and R1, R2, R3=H or an alkyl group, at least until an endpoint is reached. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of curing and modifying a low k dielectric layer on a substrate, comprising:
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providing a substrate;
coating a spin-on low k dielectric layer on said substrate;
positioning said substrate in a process chamber; and
treating said substrate with a SCF comprised of CO2 and H2O2 wherein the CO2 flow rate is from about 1000 to 15000 standard cubic centimeters per minute (sccm) and the H2O2 flow rate is between 0 and about 1000 sccm.
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12. A method of curing and modifying a low k dielectric layer on a substrate, comprising:
-
providing a substrate;
coating a spin-on low k dielectric layer on said substrate;
positioning said substrate in a process chamber; and
treating said substrate with a supercritical fluid (SCF) comprised of CO2 and a co-solvent which is H2O2, CF3—
X, or Y—
F wherein X=NR1R2, —
OR3, —
O2CR3, —
(C═
O)R3, or R3 and wherein Y=H or an alkyl group and R1, R2, R3=H or an alkyl group wherein said SCF is further comprised of a second co-solvent that is selected from the aforementioned co-solvents CF3—
X, Y—
F, and H2O2 and wherein the second co-solvent is different than the first co-solvent. - View Dependent Claims (13, 14, 15)
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16. A damascene process comprising the steps of:
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(a) providing a substrate upon with an etch stop layer formed thereon;
(b) coating a spin-on low k dielectric layer on said etch stop layer;
(c) curing and modifying said low k dielectric layer by treating with a supercritical fluid comprised of CO2 an a co-solvent which is H2O2, CF3—
X, or Y—
F wherein X=NR1R2, —
OR3, —
O2CR3, —
(C═
O)R3, or R3 and wherein Y=H or an alkyl group and R1, R2, R3=H or an alkyl group;
(d) forming an opening in the stack comprised of said low k dielectric layer and said etch stop layer;
(e) depositing a barrier metal liner in said opening;
(f) depositing a metal on said barrier metal liner to fill said opening; and
(g) planarizing said metal so that it is coplanar with said low k dielectric layer. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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36. An apparatus for curing and modifying a low k dielectric material on a substrate, comprising a continuous loop SCF system that can withstand pressures from about 70 to 700 atmospheres and temperatures of about 30°
- C. to 150°
C., comprising;(a) a process chamber capable of holding a 300 mm wafer in place during a supercritical fluid (SCF) treatment;
(b) a port with a connection to an end point detection system;
(c) a separator for removing co-solvents, solids, monomers, O2, and N2 from the SCF;
(d) a hydrocarbon knock out chamber;
(e) a chiller;
(f) a working CO2 tank;
(g) a make up tank for CO2 and a source tank for a first co-solvent and a second source tank for a second co-solvent;
(h) a preheater for heating the SCF in the loop before entering the process chamber;
(i) a CO2 pump and pumps for introducing co-solvents into the continuous loop system;
(j) tubing and valves for directing, regulating, and containing the SCF flow within the continuous loop;
(k) a supercritical fluid comprised of CO2 and one or more co-solvents selected from a group including H2O2, CF3—
X, or Y—
F wherein X=NR1R2, —
OR3, —
O2CR3, —
(C═
O)R3, or R3 and wherein Y=H or an alkyl group and R1, R2, R3=H or an alkyl group. - View Dependent Claims (37, 38, 39, 40, 41, 42)
- C. to 150°
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43. An apparatus for curing and modifying a low k dielectric material on a substrate, comprising a continuous loop SCF system that can withstand pressures from about 70 to 700 atmospheres and temperatures of about 30°
- C. to 150°
C., comprising;a process chamber capable of holding a 300 mm wafer in place during a supercritical fluid (SCF) treatment;
a port with a connection to an end point detection system;
a separator for removing co-solvents, solids, monomers, O2, and N2 from the SCF;
a hydrocarbon knock out chamber;
a chiller;
a working CO2 tank;
a make up tank for CO2 and a source tank for a first co-solvent and a second source tank for a second co-solvent;
a preheater for heating the SCF in the loop before entering the process chamber wherein the continuous loop from the CO2 pump passes through a preheater or a by-pass loop around said preheater just prior to entering the process chamber;
a CO2 pump and pumps for introducing co-solvents into the continuous loop system;
tubing and valves for directing, regulating, and containing the SCE flow within the continuous loop; and
a supercritical fluid comprised of CO2 and one or more co-solvents selected from a group including H2O2, CF3—
X, or Y—
F wherein X=NR1R2, —
OR3, —
O2 CR3, —
(C═
O)R3, or R3 and wherein Y=H or an alkyl group and R1, R2, R3=H or an alkyl group.
- C. to 150°
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44. An apparatus for treating a low k dielectric material on a substrate comprising:
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a process chamber;
an end point detection system in fluid communication with the process chamber;
a separator in fluid communication with the process chamber;
a hydrocarbon knock out chamber in fluid communication with the separator;
a chiller in fluid communication with the hydrocarbon knock out chamber;
a CO2 working tank in fluid communication with the chiller;
a CO2 make up tank in fluid communication with the CO2 working tank;
a CO2 pump in fluid communication with the CO2 working tank;
a source tank for a first co-solvent;
a first co-solvent pump in fluid communication with the first co-solvent source tank and in fluid communication with the CO2 pump;
a preheater in fluid communication with the CO2 pump;
a supercritical fluid (SCF) comprised of CO2 and at least one co-solvent; and
tubing and valves for directing, regulating, and containing the SCF flow within a continuous loop. - View Dependent Claims (45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67)
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68. A method of treating a low k dielectric layer on a substrate comprising:
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spinning a low k dielectric layer onto a substrate; and
treating the layer with a supercritical fluid (SCF) comprised of CO2 and first co-solvent H2O2, wherein the layer is treated at least until an endpoint is reached. - View Dependent Claims (69, 70, 71, 72, 73, 74)
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75. A method of treating a low k dielectric layer on a substrate comprising:
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spinning a low k dielectric layer onto a substrate; and
treating the layer with a supercritical fluid (SCF) comprised of CO2 and first co-solvent H2O2, wherein the CO2 flow rate is about 1000 to 15000 sccm and the H2O2 flow rate is about 50 to 1000 sccm.
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76. A method of treating a low k dielectric layer on a substrate comprising:
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spinning a low k dielectric layer onto a substrate; and
treating the layer with a supercritical fluid (SCF) comprised of CO2 and first co-solvent H2O2, wherein the SCF further comprises a second co-solvent, and wherein the second co-solvent is CF3—
X where X=NR1R2, —
OR3, —
O2CR3, —
(C═
O)R3, or R3 and where R1, R2, R3=H or an alkyl group. - View Dependent Claims (77)
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78. A method of treating a low k dielectric layer on a substrate comprising:
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spinning a low k dielectric layer onto a substrate; and
treating the layer with a supercritical fluid (SCF) comprised of CO2 and first co-solvent H2O2, wherein the SCF further comprises a second co-solvent, and wherein the second co-solvent is Y—
F where Y=H or an alkyl group, and wherein the CO2 flow rate is about 1000 to 15000 sccm, the H2O2 flow rate is about 50 to 1000 sccm, and the Y—
F flow rate is about 50 to 100 sccm.
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Specification