USE OF A CHEMICAL MECHANICAL POLISHING (CMP) COMPOSITION FOR POLISHING OF COBALT AND / OR COBALT ALLOY COMPRISING SUBSTRATES

Abstract

A chemical mechanical polishing (CMP) composition (Q) for chemical mechanical polishing of a substrate (S) containing (i) cobalt and/or (ii) a cobalt alloy, wherein the CMP composition (Q) contains: (A) Inorganic particles, (B) a substituted aromatic compound with at least one carboxylic acid function as corrosion inhibitor, (C) at least one amino acid, (D) at least one oxidizer, (E) an aqueous medium, wherein the CMP composition (Q) has a pH of from 7 to 10.

Claims

1. A method for chemical mechanical polishing of a substrate (S) comprising (i) cobalt and/or (ii) a cobalt alloy, wherein the method comprises: chemical mechanical polishing of said substrate with a chemical mechanical polishing (CMP) composition, said composition comprising (A) an inorganic particle, (B) a substituted aromatic compound with at least one carboxylic acid function of the general formula 1 to 5 as corrosion inhibitor ##STR00003## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are independently from each other H, hydroxy, alkyl, amino, aryl alkylamino, alkylarylamino, benzylamino, carboxyl, alkylsulfonyl, sulfonic acid, sulfonate, thio or alkylthio, (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.

2. The method according to claim 1, wherein the inorganic particles (A) are colloidal inorganic particles.

3. The method according to claim 2, wherein the colloidal inorganic particles are silica particles.

4. The method according to claim 1, wherein the substituted aromatic compound with at least one carboxylic acid function (B) is at least one of the general formula 1 to 5, and wherein R.sup.1 is amino, mono-alkylamino, di-alkyamino, carboxyl, alkythio or alkylsulfonyl, R.sup.2 is amino, mono-alkylamino, di-alkyamino or carboxyl, R.sup.3 is benzylamino, R.sup.4 is amino, mono-alkylamino, di-alkyamino and R.sup.5 is amino, carboxyl or alkyl.

5. The method according to claim 1, wherein the substituted aromatic compound with at least one carboxylic acid function (B) is at least one of the general formula 1 to 5 and wherein R.sup.1 is amino, mono-methylamino, di-methylamino, di-ethylamino, carboxyl or methylsulfonyl, R.sup.2 is amino, mono-methylamino, di-methylamino or carboxyl, R.sup.3 is benzylamino, R.sup.4 is amino, and R.sup.5 is amino or carboxyl.

6. The method according to claim 1, wherein a total amount of the substituted aromatic compound with at least one carboxylic acid function (B) of one of general formula 1 to 5 is in the range of from 0.002 wt.-% to 0.15 wt.-% based on the total weight of the respective CMP composition.

7. The method according to claim 1, wherein the at least one amino acids (C) is glycine, alanine, leucine, valine, cysteine, serine and proline or a salt thereof.

8. The method according to claim 1, wherein a total amount of the at least one amino acid (C) is in the range of from 0.1 wt.-% to 2.25 wt.-% based on the total weight of the respective CMP composition.

9. The method according to claim 1 wherein the oxidizer comprises a peroxide.

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

11. A chemical mechanical polishing (CMP) composition, comprising: (A) colloidal silica particles in a total amount of from 0.01 wt.-% to 3 wt.-% based on the total weight of the respective CMP composition, (B) at least one substituted aromatic compound with at least one carboxylic acid function (B) selected from the group consisting of isophathalic acid, terephthalic acid, 2-aminoterephthalic acid, 4-methylamino benzoic acid, 4-(dimethylamino)benzoic acid, 4-methylsulfonyl benzoic acid, trimesic acid, 3-methylamino benzoic acid, 4-(diethylamino)benzoic acid, 3-dimethylamino benzoic acid and 2-(benzylamino)benzoic acid in a total amount of from 0.002 wt.-% to 0.1 wt.-% based on the total weight of the respective CMP composition, (C) at least one amino acids (C) selected from the group consisting of glycine, alanine, leucine, valine, cysteine, serine and proline and a salt thereof, in a total amount of from 0.2 wt.-% to 0.9 wt.-% based on the total weight of the respective CMP composition, (D) hydrogen peroxide in a total amount of from 0.2 wt.-% to 2 wt.-% based on the total weight of the respective CMP composition, and (E) an aqueous medium, wherein the CMP composition (Q) has a pH of from 7 to 10.

12. A process for the manufacture of a semiconductor device, said process comprising: chemical mechanical polishing of a substrate (S) used in the semiconductor industry, in the presence of a chemical mechanical polishing CMP composition (Q); p1 wherein the substrate (S) comprises (i) cobalt and/or (ii) a cobalt alloy; wherein the (CMP) composition comprises (A) an inorganic particle, (B) a substituted aromatic compound with at least one carboxylic acid function of the general formula 1 to 5 as corrosion inhibitor ##STR00004## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are independently from each other H, hydroxy, alkyl, amino, aryl alkylamino, alkylarylamino, benzylamino, carboxyl, alkylsulfonyl, sulfonic acid, sulfonate, thio or alkylthio, (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.

13. The process according to claim 12, wherein a static etch rate (SER) of cobalt is below 100 Å/min.

14. The process according to claim 12, wherein a cobalt material removal rate (MRR) is adjusted to a range of from 300 to 7200 Å/min.

Description

[0189] The figures show:

[0190] FIG. 1: Schematic illustration of the variation of the shape factor with the shape of a particle

[0191] FIG. 2: Schematic illustration of the variation of the sphericity with the elongation of a particle

[0192] FIG. 3: Schematic illustration of the Equivalent Circle Diameter (ECD)

[0193] 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

[0194] The general procedure for the CMP experiments is described below.

[0195] Standard CMP process for 200 mm Co/Co wafers:

[0196] Strasbaugh nSpire (Model 6EC), ViPRR floating retaining ring Carrier;

[0197] down pressure: 1.5 psi;

[0198] back side pressure: 1.0 psi;

[0199] retaining ring pressure: 1.0 psi;

[0200] polishing table/carrier speed: 130/127 rpm;

[0201] slurry flow rate: 300 ml/min;

[0202] polishing time: 15 s; (Co) [0203] 60 s; (Cu)

[0204] polishing pad: Fujibo H800;

[0205] backing film: Strasbaugh, DF200 (136 holes);

[0206] conditioning tool: Strasbaugh, soft brush, ex-situ; after each wafer the pad is [0207] conditioned for the next processing of an other wafer by 2 sweeps with 51 bs 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.

[0208] Three dummy TEOS wafers are polished with 60s before the metal wafers are polished (Co wafer is polished for 15 s).

[0209] The slurry is stirred in the local supply station.

[0210] Standard analysis procedure for metal blanket wafers:

[0211] 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.

[0212] The radial unifomity of removal rate is assessed by 39 point diameter scan (range) using NAPSON 4-point probe station.

[0213] Standard consumables for CMP of metal film coated wafers:

[0214] Co films: 2000 A PVD Co on Ti liner (Supplier: AMT); The pH-value is measured with a pH combination electrode (Schott, blue line 22 pH electrode).

[0215] Standard procedure for determination of the Co static etch rate (Co-SER):

[0216] 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

[0217] Standard procedure for slurry preparation:

[0218] 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 substituted aromatic compound (B) 1 wt. % is prepared by dissolving the desired amount of substituted aromatic compound (B) in ultra-pure water and stirring for 30 minutes until all of the solid of the substituted aromatic compound is dissolved.

[0219] To prepare the CMP slurry of the examples the glycine (amino acid (C)) solution, the substituted aromatic compound (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 H.sub.2O.sub.2 (D) is added right before (1 to 15 min) before the slurry is used for CMP.

[0220] Inorganic particles (A) used in the Examples

[0221] 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.

TABLE-US-00001 TABLE 1 Experimental results of particle shape analysis of cocoon-shaped silica particles (A) statistical function ECD unit nm shericity shape factor 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

[0222] Procedure for particle shape characterization

[0223] 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.

[0224] 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.

TABLE-US-00002 TABLE 2 CMP compositions of the examples 1 to 4 and 16 to 27 and of the comparative examples V1 to V4, 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 0.5 wt. % H.sub.2O.sub.2 0.5 wt. % H.sub.2O.sub.2 1 wt. % Compound (B) BTA Isophthalic acid Terephthalic Isophthalic acid (Benzotriazole) 0.0025 wt % acid 0.5 wt % 0.03 wt % 0.0025 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 6500  6204  222  Co-SER [Å/min] 654 37 32 47 Comparative Comparative Example 3 Example 4 Example V3 Example V4 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) Isophthalic acid Isophthalic acid Isophthalic acid Terephthalic 0.01 wt % 0.01 wt % 0.01 wt % acid 0.5 wt % Glycine (C) 2.25 wt. % 1.5 wt. % 3 wt. % 0.75 wt. % pH   8.3   8.3   8.3   8.3 Co-MRR [Å/min] 7133  3728  8424  334  Co-SER [Å/min] 19 71 90 38 Example 16 Example 17 Example 18 Example 19 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) Isophthalic acid Isophthalic acid Isophthalic acid Isophthalic acid 0.0025 wt % 0.005 wt % 0.007 wt % 0.009 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] 2134  2076  1712  1416  Co-SER [Å/min] 49 79 54 44 Example 20 Example 21 Example 22 Example 23 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) Terephthalic Terephthalic Terephthalic Terephthalic acid acid acid acid 0.0025 wt % 0.005 wt % 0.007 wt % 0.009 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] 1608  1844  1252  948  Co-SER [Å/min] 64 80 52 49 Example 24 Example 25 Example 26 Example 27 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) Trimesic acid Trimesic acid Trimesic acid Trimesic acid 0.0025 wt % 0.005 wt % 0.007 wt % 0.009 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] 524  380  328  384  Co-SER [Å/min] 76 58 84 71

TABLE-US-00003 TABLE 3 Co-SER (static etching rates) [Å/min] for the CMP compositions of the examples 5 to 15 and the comparative examples V5 to V8: Comparative Comparative Example V5 Example V6 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) Isophthalic acid Terephthalic Isophthalic acid Isophthalic acic 0.001 wt % acid 0.0025 wt % 0.01 wt % 0.001 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] 118 273 37 11 Example 7 Example 8 Example 9 Example 10 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) Isophthalic acid Isophthalic acid Terephthalic Terephthalic 0.03 wt % 0.05 wt % acid acid 0.0025 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] 30 23 32 20 Example 11 Example 12 Example 13 Example 14 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) Terephthalic 4-(Dimethyl-amino) 4-(Diethyl-amino) 2-(Benzylamino) acid benzoic acid benzoic acid benzoic acid 0.05 wt % 0.03 wt % 0.03 wt % 0.03 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] 2 35 66 20 Comparative Comparative Example 15 Example V7 Example V8 Particles (A)   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. % Compound (B) Trimesic acid 4-(amino-methyl) 1,2,4,5- 0.03 wt % benzoic acid benzenetetracar- 0.03 wt % boxylic acid 0.03 wt % Glycine (C) 0.75 wt. % 0.75 wt. % 0.75 wt. % pH   8.3    8.3    8.3 Co-SER [Å/min] 38 590 172

[0225] 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.