Use of a chemical mechanical polishing (CMP) composition for polishing of cobalt and / or cobalt alloy comprising substrates

Abstract

Use of a chemical mechanical polishing (CMP) composition (Q) for chemical mechanical polishing of a substrate (S) comprising (i) cobalt and/or (ii) a cobalt alloy, wherein the CMP composition (Q) comprises (A) Inorganic particles (B) an anionic surfactant of the general formula (I) R-S wherein R is C.sub.5-C.sub.20-alkyl, C.sub.5-C.sub.20-alkenyl, C.sub.5-C.sub.20-alkylacyl or C.sub.5-C.sub.20-alkenylacyl and S is a sulfonic acid derivative, an amino acid derivative or a phosphoric acid derivative or salts or mixtures thereof (C) at least one amino acid, (D) at least one oxidizer (E) an aqueous medium and wherein the CMP composition (Q) has a pH of from 7 to 10.

Claims

1. A method of polishing a substrate, the method comprising: contacting the substrate with a chemical mechanical polishing composition, wherein the substrate comprises cobalt, and wherein the chemical mechanical polishing composition has a pH in a range of from 7 to 10 and comprises (A) inorganic particles, (B) an anionic surfactant of formula (I),
R−S(I), R being a C.sub.5-C.sub.20-alkyl group, a C.sub.5-C.sub.20-alkenyl group, a C.sub.5-C.sub.20-alkylacyl group, or a C.sub.5-C.sub.20-alkenylacyl group, and S is a sulfonic acid derivative, an amino acid derivative, and/or a phosphoric acid derivative, optionally as a salt, (C) an amino acid selected from the group consisting of glycine, alanine, leucine, valine, cysteine, serine, and proline, in a total amount of from 0.65 to 0.78 wt %, based on total chemical mechanical polishing composition weight, (D) an oxidizer, and (E) an aqueous medium.

2. The method of claim 1, wherein the inorganic particles are colloidal.

3. The method of claim 1, wherein the inorganic particles are colloidal silica particles.

4. The method of claim 1, wherein, in the anionic surfactant, R is hexyl, septyl, octyl, nonyl, decyl, hexenyl, septenyl, octenyl, nonyl, decenyl, undecenyl, dodecenyl, oleoyl, lauroyl, or cocoyl, and S is sulfonic acid, benzenesulfonic acid, a mono substituted benzenesulfonic acid, sarcosine, glutamic acid, phosphoric acid, or a mono phosphoric acid ester, optionally as a salt.

5. The method of claim 1, wherein, in the anionic surfactant, R is hexyl, octyl, undecyl, dodecenyl, oleoyl, lauroyl, or cocoyl, and S is sulfonic acid, benzenesulfonic acid, sarcosine, glutamic acid, phosphoric acid, or a mono phosphoric acid ester, optionally as a salt.

6. The method of claim 1, wherein the anionic surfactant is present in a range of from 0.001 to 0.09 wt %, based on total composition weight.

7. The method of claim 1, wherein the amino acid comprises glycine, optionally as a salt.

8. The method of claim 1, wherein the amino comprises serine.

9. The method of claim 1, wherein the oxidizer comprises a peroxide.

10. The method of claim 1, wherein the oxidizer is hydrogen peroxide.

11. The method of claim 1, wherein the substrate comprises a cobalt alloy.

12. The method of claim 1, wherein the substrate is cobalt.

13. The method of claim 1, wherein the amino acid comprises alanine, optionally as a salt.

14. The method of claim 1, wherein the amino acid comprises leucine, optionally as a salt.

15. The method of claim 1, wherein the amino acid comprises valine, optionally as a salt.

16. The method of claim 1, wherein the amino acid comprises cysteine and/or proline, optionally as a salt.

17. The method of claim 1, wherein the amino acid is present in the chemical mechanical polishing composition in an amount of 0.75 wt % based on total chemical mechanical polishing composition weight.

18. A chemical mechanical polishing composition, comprising, based on total composition weight: (A) colloidal silica particles in a total amount of from 0.01 to 3 wt %; (B) an anionic surfactant comprising N-oleoylsarcosine, N-lauroylsarcosine, N-cocoylsarcosine, 4-dodecylbenzene sulfonic acid, N-cocoylglutamate, and/or a phosphoric acid C.sub.6-C.sub.10 alkyl ester, in a total amount of from 0.001 to 0.09 wt %; (C) an amino acid, optionally as salt, comprising glycine, alanine, leucine, valine, cysteine, serine, and/or proline, in a total amount of from 0.2 to 0.9 wt %; (D) hydrogen peroxide in a total amount of from 0.2 to 2 wt %; and (E) an aqueous medium, wherein the composition has a pH in a range of from 7 to 10.

19. A process of manufacturing a semiconductor device, the process comprising polishing a substrate comprising cobalt in the presence of the composition of claim 18.

20. The process of claim 19, wherein a static etch rate of the cobalt is less than 100 Åmin.

21. The process of claim 19, wherein a material removal rate of the cobalt is in a range of from 300 to 6500 Å/min.

Description

(1) The figures show:

(2) FIG. 1: Schematic illustration of the variation of the shape factor with the shape of a particle

(3) FIG. 2: Schematic illustration of the variation of the sphericity with the elongation of a particle

(4) FIG. 3: Schematic illustration of the Equivalent Circle Diameter (ECD)

(5) FIG. 4: Energy Filtered-Transmission Electron Microscopy (EF-TEM) (120 kilo volts) image of a dried cocoon-shaped silica particle dispersion with 20 wt. % solid content on a carbon foil

EXAMPLES AND COMPARATIVE EXAMPLES

(6) The general procedure for the CMP experiments is described below.

(7) Standard CMP process for 200 mm Co/Co wafers:

(8) Strasbaugh nSpire (Model 6EC), ViPRR floating retaining ring Carrier; down pressure: 1.5 psi; back side pressure: 1.0 psi; retaining ring pressure: 1.0 psi; polishing table/carrier speed: 130/127 rpm; slurry flow rate: 300 ml/min; polishing time: 15 s; (Co) 60 s; (Cu) polishing pad: Fujibo H800; backing film: Strasbaugh, DF200 (136 holes); conditioning tool: Strasbaugh, soft brush, ex-situ; after each wafer the pad is conditioned for the next processing of an other wafer by 2 sweeps with 5 lbs down force. The brush is soft. This means even after 200 sweeps the brush will not have caused a significant removal rate on the soft polishing pad.

(9) Three dummy TEOS wafers are polished with 60 s before the metal wafers are polished (Co wafer is polished for 15 s).

(10) The slurry is stirred in the local supply station.

(11) Standard analysis procedure for metal blanket wafers:

(12) Removal rate is determined by difference of weight of the wafers pre and post CMP by a Sartorius LA310 S scale or a NAPSON 4-point probe station.

(13) The radial uniformity of removal rate is assessed by 39 point diameter scan (range) using NAPSON 4-point probe station.

(14) Standard consumables for CMP of metal film coated wafers:

(15) Co films: 2000 A PVD Co on Ti liner (Supplier: AMT);

(16) The pH-value is measured with a pH combination electrode (Schott, blue line 22 pH electrode).

(17) Standard procedure for determination of the Co static etch rate (Co-SER):

(18) Co-SER experiments were carried on as the following. 2.5×2.5 cm PVD Co (from AMT) were cut and washed with DI water. Co film thickness (dbefore) was measured with a 4-point probe. 400 ml of fresh prepared slurry with 0.5% H2O2 was put in a beaker and brought to 50° C. afterwards. Co coupon was placed into the slurry and kept in the slurry for 3 min. Then the coupon was washed and dried with N2. The Co film thickness (dafter) was measured with the same device again. The Co-SER was determined by the following formula:
SER(A/min)=(dbefore−dafter)/3

(19) Standard procedure for slurry preparation:

(20) An aqueous solution of glycine 10 wt. % is prepared by dissolving the desired amount of glycine in ultra-pure water. After stirring for 20 min the solution is neutralized and the pH is adjusted to pH 8.05±0.1 by adding an 4.8 wt. % aqueous solution of KOH. Balance water may be added to adjust concentration. An aqueous stock solution of the respective anionic surfactant (B) 1 wt. % is prepared by dissolving the desired amount of anionic surfactant (B) in ultra-pure water and stirring for 30 minutes until all of the solid of the anionic surfactant is dissolved.

(21) To prepare the CMP slurry of the examples the glycine (amino acid (C)) solution, the anionic surfactant (corrosion inhibitor (B)) solution are mixed and a solution of colloidal silica particles (20% stock solution of (A) for example Fuso® PL 3) is added under continuous stirring. After the complete addition of the desired amount of abrasive (A) the dispersion is stirred for additional 5 minutes. Then the pH is adjusted to 8.3±0.1 by adding an 4.8 wt. % aqueous solution of KOH. Balance water is added under stirring to adjust the concentration of the CMP slurry to the values listed in the tables 2 and table 3 of the examples and comparative examples below. Thereafter the dispersion is filtered by passing through a 0.2 μm filter at room temperature. The desired amount of H2O.sub.2 (D) is added right before (1 to 15 min) before the slurry is used for CMP.

(22) Inorganic Particles (A) Used in the Examples

(23) Colloidal cocoon-shaped Silica particles (A1) having an average primary particle size (d1) of 35 nm and an average secondary particle size (d2) of 70 nm (as determined using dynamic light scattering techniques via a Horiba instrument) (for example Fuso® PL-3) and a specific surface area of around 46 m.sup.2/g were used.

(24) TABLE-US-00001 TABLE 1 Experimental results of particle shape analysis of cocoon-shaped silica particles (A) statistical function ECD shericity shape factor unit nm number of particles 475 475 475 average 53.67 0.631 0.881 minimum 33.68 0.150 0.513 maximum 99.78 0.997 0.978 standard deviation 11.69 0.199 0.083 median d50 51.32 0.662 0.911 d90 0.955
Procedure for Particle Shape Characterization

(25) An aqueous cocoon-shaped silica particle dispersion with 20 wt. % solid content was dispersed on a carbon foil and was dried. The dried dispersion was analyzed by using Energy Filtered-Transmission Electron Microscopy (EF-TEM) (120 kilo volts) and Scanning Electron Microscopy secondary electron image (SEM-SE) (5 kilo volts). The EF-TEM image with a resolution of 2 k, 16 Bit, 0.6851 nm/pixel (FIG. 4) was used for the analysis. The images were binary coded using the threshold after noise suppression. Afterwards the particles were manually separated. Overlying and edge particles were discriminated and not used for the analysis. ECD, shape factor and sphericity as defined before were calculated and statistically classified.

(26) A2 are agglomerated particles with a specific surface area of around 90 m.sup.2/g having an average primary particle size (d1) of 35 nm and an average secondary particle size (d2) of 75 nm (as determined using dynamic light scattering techniques via a Horiba instrument) (for example Fuso® PL-3H) were used.

(27) TABLE-US-00002 TABLE 2 CMP compositions of the examples 1 to 2 and of the comparative examples V1 to V3, their pH values, pH variations, concentration variations, Co-SER data as well as their Co-MRR data in the process of chemical-mechanical polishing of 200 mm Co wafers using these compositions, wherein the aqueous medium (E) of the CMP compositions is de-ionized water. The amounts of the components (A), (B), (C) and (D) are specified in weight percent (wt. %) by weight of the corresponding CMP composition. If the amounts of the components other than (E) are in total y % by weight of the CMP composition, then the amount of (E) is (100-y) % by weight of the CMP composition. Comparative Comparative Example V1 Example 1 Example 2 Example V2 Particles (A) A1 0.5 wt. % A1 0.5 wt. % A1 0.5 wt. % A1 0.5 wt. % H.sub.2O.sub.2 (D) H.sub.2O.sub.2 1 wt. % H.sub.2O.sub.2 1 wt. % H.sub.2O.sub.2 1 wt. % H.sub.2O.sub.2 1 wt. % Compound (B) BTA 4-dodecyl-benzene phosphoric acid 4-dodecyl-benzene (Benzotriazole) sulfonic acid C.sub.6-C.sub.10 alkyl sulfonic acid 0.03 wt % 0.005 wt % ester 0.001 wt % 0.2 wt % Glycine (C) 0.75 wt. % 0.75 wt. % 0.75 wt. % 0.75 wt. % pH 8.3 8.3 8.3 8.3 Co-MRR [Å/min] 718 616 5952 28 Co-SER [Å/min] 654 20 38 7 Comparative Example V3 Particles (A) A1 0.5 wt. % H.sub.2O.sub.2 (D) H.sub.2O.sub.2 1 wt. % Compound (B) phosphoric acid C.sub.6-C.sub.10 alkyl ester 0.1 wt % Glycine (C) 0.75 wt. % pH 8.3 Co-MRR [Å/min] 26 Co-SER [Å/min] 4

(28) TABLE-US-00003 TABLE 3 Co-SER (static etching rates) [Å/min] for the CMP compositions of the examples 3 to 13: Example 3 Example 4 Example 5 Example 6 Particles (A) A1 0.5 wt. % A1 0.5 wt. % A1 0.5 wt. % A1 0.5 wt. % H.sub.2O.sub.2 (D) H.sub.2O.sub.2 0.5 wt. % H.sub.2O.sub.2 0.5 wt. % H.sub.2O.sub.2 0.5 wt. % H.sub.2O.sub.2 0.5 wt. % Compound (B) phosphoric acid phosphoric acid phosphoric acid phosphoric acid C.sub.6-C.sub.10 alkyl C.sub.6-C.sub.10 alkyl C.sub.6-C.sub.10 alkyl C.sub.6-C.sub.10 alkyl ester 0.001 wt % ester 0.0025 wt % ester 0.01 wt % ester 0.05 wt % Glycine (C) 0.75 wt. % 0.75 wt. % 0.75 wt. % 0.75 wt. % pH 8.3 8.3 8.3 8.3 Co-SER [Å/min] 38 7 24 7 Example 7 Example 8 Particles (A) A1 0.5 wt. % A1 0.5 wt. % H.sub.2O.sub.2 (D) H.sub.2O.sub.2 0.5 wt. % H.sub.2O.sub.2 0.5 wt. % Compound (B) 4-dodecyl-benzene 4-dodecyl-benzene sulfonic acid sulfonic acid 0.01 wt % 0.05 wt % Glycine (C) 0.75 wt. % 0.75 wt. % pH 8.3 8.3 Co-SER [Å/min] 24 23 Example 9 Example 10 Example 11 Example 12 Particles (A) A1 0.5 wt. % A1 0.5 wt. % A1 0.5 wt. % A1 0.5 wt. % H.sub.2O.sub.2 (D) H.sub.2O.sub.2 0.5 wt. % H.sub.2O.sub.2 0.5 wt. % H.sub.2O.sub.2 0.5 wt. % H.sub.2O.sub.2 0.5 wt. % Compound (B) N-Oleoyl-sarcosine N-Oleoyl-sarcosine N-Lauroyl-sarcosine N-Cocoyl-sarcosine 0.005 wt % 0.01 wt % 0.01 wt % 0.01 wt % Glycine (C) 0.75 wt. % 0.75 wt. % 0.75 wt. % 0.75 wt. % pH 8.3 8.3 8.3 8.3 Co-SER [Å/min] 3 3 6 7 Example 13 Particles (A) A1 0.5 wt. % H.sub.2O.sub.2 (D) H.sub.2O.sub.2 0.5 wt. % Compound (B) N-Cocoyl-glutamate 0.03 wt % Glycine (C) 0.75 wt. % pH 8.3 Co-SER [Å/min] 20

(29) The CMP compositions according to the invention are showing an improved polishing performance in terms of cobalt material removal rates (MRR) [Å/min] and a drastic decrease in the Co etching rates as can be demonstrated by the examples shown in table 2 and table 3.