TWI601808B - Chemical mechanical polishing method - Google Patents

Description

Chemical mechanical polishing method

The invention relates to the field of chemical mechanical polishing. In particular, the present invention relates to a method of chemically mechanically grinding a substrate comprising tungsten and titanium, comprising: providing the substrate; providing a chemical mechanical polishing composition comprising, as an initial component: water; an oxidizing agent; chitosan; An acid, wherein the dicarboxylic acid is selected from the group consisting of malonic acid and 2-hydroxymalonic acid; a source of iron ions; a colloidal ceria abrasive with a positive surface charge; and, optionally, a pH adjuster Providing a chemical mechanical polishing pad having an abrasive surface; generating dynamic contact at an interface between the chemical mechanical polishing pad and the substrate; and dispersing the chemical mechanical polishing composition on the abrasive surface of the chemical mechanical polishing pad at or near An interface between the chemical mechanical polishing pad and the substrate; wherein a portion of the tungsten (W) and a portion of the titanium (Ti) are removed from the substrate by the removal selectivity of tungsten (W) relative to the titanium (Ti) Remove by grinding.

When manufacturing integrated circuits and other electronic devices, multilayer conductors, semiconductors, and dielectric materials are deposited or removed from the surface of the semiconductor wafer. Thin layers of conductors, semiconductors, and dielectric materials can be deposited by several deposition techniques. Common deposition techniques in modern processes include physical vapor deposition (PVD), also known as sputtering, chemical vapor deposition (CVD), and plasma growth. Strong chemical vapor deposition (PECVD), and electrochemical plating (ECP).

When the layers of material are sequentially deposited and removed, the uppermost surface of the wafer may become uneven. Since the subsequent semiconductor process (such as metallization) requires the wafer to have a flat surface, the wafer needs to be planarized. Planarization can be used to remove undesirable surface geometry and surface defects such as rough surfaces, build-up materials, lattice damage, scratches, and contaminated layers or materials.

Chemical mechanical planarization, or chemical mechanical polishing (CMP), is a common technique for planarizing substrates such as semiconductor wafers. In conventional CMP, the wafer is placed on a carrier assembly and positioned in contact with a polishing pad within the CMP apparatus. The carrier assembly provides a controlled pressure against the wafer against the polishing pad. The pad is moved (eg, rotated) relative to the wafer by an external driving force. At the same time, an abrasive composition (slurry) or other slurry is provided between the wafer and the polishing pad. Thus, the wafer surface is ground and flattened by the chemical and mechanical action of the pad surface and the slurry.

Chemical mechanical polishing has become a preferred method of grinding tungsten in the formation of integrated circuit designs when tungsten wires and contact plugs are formed. Tungsten is often used in integrated circuit designs as contact/via plugs. In general, the contacts or vias are formed by penetrating a dielectric layer on the substrate to expose underlying component regions (eg, first layer metallization or bonding lines). Titanium (Ti) is typically applied as an adhesive layer on the sides and bottom of the contact or via, prior to tungsten deposition. The tungsten cap layer and the titanium adhesive layer are then ground down to provide a surface that is coplanar with the dielectric.

Another application of tungsten in integrated circuit design is as a local connection line that forms wires between features of the same device layer. Form local One method of connecting wires relies on Damascene processing. The first metal layer is inlaid to the lowest dielectric layer (ILDO). This involves first depositing the ILDO, followed by patterning and etching the trenches in the dielectric layer. In general, a layered structure is then formed in the trench, which is deposited with titanium and tungsten and is located on the dielectric surface, wherein the titanium is between the tungsten and the dielectric layer. The CMP is then used to remove the titanium and tungsten down to the dielectric surface, leaving the tungsten wire in the trench as a local connection. For chemical mechanical polishing applications, all tungsten and titanium conductive residues must be removed from the dielectric surface to prevent shorting of the device. The next step in chemical mechanical polishing is to deposit the next layer of dielectric. Therefore, if tungsten and titanium cannot be removed from the lower dielectric layer, it will remain in the device to be fabricated and cause a short circuit.

All traditional CMP mechanisms have not been able to form the desired tungsten characteristics. All chemical mechanical polishing methods have various defect problems. For example, the ideal grinding rate required for various materials is quite difficult to achieve.

As a result, various alternative strategies have been devised for forming an intra-level and inter-level tungsten connection on a semiconductor substrate. A two-step strategy is provided, for example, in U.S. Patent No. 6,211,087, to Gabriel et al. In particular, Gabriel et al. disclose a method of planarizing a substrate in which a layer of tungsten is deposited on a layer of titanium in a hole or trench in the substrate. First, a chemical mechanical polishing step is performed using an abrasive slurry that selectively removes tungsten relative to the titanium adhesive layer to remove the tungsten covered thereon. Thereafter, a chemical etching step is performed using a chemical wet etchant selective to the titanium paste layer to promote etch back to the dielectric.

Still, there is a constant need to use new chemical machines. The mechanically abrasive composition is formed on the semiconductor substrate to form a tungsten-bonding line between the inner layer and the intermediate layer thereof, as disclosed in U.S. Patent No. 6,211,087, wherein the chemical mechanical polishing composition is used for selective removal of tungsten, In titanium.

The present invention provides a method of polishing a substrate, comprising: providing a substrate, wherein the substrate comprises tungsten (W) and titanium (Ti); providing a chemical mechanical polishing composition comprising, as an initial component: water; an oxidizing agent; chitosan; a colloidal ceria abrasive with a constant positive surface charge; a dicarboxylic acid, wherein the dicarboxylic acid is selected from the group consisting of malonic acid and 2-hydroxymalonic acid; an iron (III) ion source; a pH adjusting agent; providing a chemical mechanical polishing pad having an abrasive surface; generating a dynamic contact at an interface between the chemical mechanical polishing pad and the substrate; and dispersing the chemical mechanical polishing composition on the polishing surface of the chemical mechanical polishing pad Upper or lower adjacent to the interface between the chemical mechanical polishing pad and the substrate; wherein the at least a portion of the tungsten (W) and at least a portion of the titanium (Ti) are removed from the substrate; and the chemical machinery provided therein Removal rate selectivity of tungsten (W) and titanium (Ti) in the polishing composition 100.

The present invention provides a method of polishing a substrate, comprising: providing a substrate, wherein the substrate comprises tungsten (W) and titanium (Ti); providing a chemical mechanical polishing composition comprising, as an initial component: water; an oxidizing agent; chitosan; a colloidal ceria abrasive with a constant positive surface charge; a dicarboxylic acid, wherein the dicarboxylic acid is selected from the group consisting of malonic acid and 2-hydroxymalonic acid; an iron (III) ion source; a pH adjusting agent; providing a chemical mechanical polishing pad having an abrasive surface; generating a dynamic contact at an interface between the chemical mechanical polishing pad and the substrate; and dispersing the chemical mechanical polishing composition on the polishing surface of the chemical mechanical polishing pad Upper or lower adjacent to the interface between the chemical mechanical polishing pad and the substrate; wherein the at least a portion of the tungsten (W) and at least a portion of the titanium (Ti) are removed from the substrate; and the chemical machinery provided therein Removal rate selectivity of tungsten (W) and titanium (Ti) in the polishing composition 100; the chemical mechanical polishing composition provided therein has a tungsten removal rate 1,000 Å/min, wherein the platen speed is 80 rpm, the carrier speed is 81 rpm, the chemical mechanical polishing composition has a flow rate of 125 mL/min, and the downforce is 21.4 kPa on a 200 mm grinding machine; The chemical mechanical polishing pad comprises a polyurethane abrasive layer comprising polymeric hollow particles and a non-woven sub-pad impregnated with polyurethane.

The present invention provides a method of polishing a substrate, comprising: providing a substrate, wherein the substrate comprises tungsten (W) and titanium (Ti); providing a chemical mechanical polishing composition comprising, as an initial component: water; an oxidizing agent; chitosan; a colloidal ceria abrasive with a constant positive surface charge; a dicarboxylic acid, wherein the dicarboxylic acid is selected from the group consisting of malonic acid and 2-hydroxymalonic acid; an iron (III) ion source; a pH adjusting agent; providing a chemical mechanical polishing pad having an abrasive surface; generating a dynamic contact at an interface between the chemical mechanical polishing pad and the substrate; and dispersing the chemical mechanical polishing composition on the polishing surface of the chemical mechanical polishing pad Upper or lower adjacent to the interface between the chemical mechanical polishing pad and the substrate; wherein the at least a portion of the tungsten (W) and at least a portion of the titanium (Ti) are removed from the substrate; and the chemical machinery provided therein Removal rate selectivity of tungsten (W) and titanium (Ti) in the polishing composition 100; the chemical mechanical polishing composition provided therein has a tungsten removal rate 1,000 Å/min, wherein the platen speed is 80 rpm, the carrier speed is 81 rpm, the chemical mechanical polishing composition has a flow rate of 125 mL/min, and the downforce is 21.4 kPa on a 200 mm grinding machine; The chemical mechanical polishing pad comprises a polyurethane abrasive layer comprising polymerizable hollow particles, and a non-woven sub-pad impregnated with polyurethane; and a chemical mechanical polishing composition provided therein having a titanium removal rate 50Å/min, and the removal rate selectivity of tungsten (W) and titanium (Ti) 100.

The present invention provides a method of polishing a substrate, comprising: providing a substrate, wherein the substrate comprises tungsten (W) and titanium (Ti); providing a chemical mechanical polishing composition comprising, as an initial component: water; 0.01 to 10 wt% of an oxidizing agent, wherein The oxidizing agent is hydrogen peroxide; 30 to 110 ppm by mass of chitosan, wherein the chitosan has a weight average molecular weight distribution of 50,000 to 500,000 Daltons; 0.01 to 10% by weight of colloidal ceria abrasive; 100 To 1,300 ppm by mass of a dicarboxylic acid, wherein the dicarboxylic acid is malonic acid; 100 to 1,000 ppm by mass of an iron (III) ion source, wherein the iron (III) ion source is ferric nitrate nonahydrate; and selectivity a pH adjusting agent; and wherein the chemical mechanical polishing composition has a pH of 1 to 4; providing a chemical mechanical polishing pad having an abrasive surface; generating a dynamic contact at an interface between the chemical mechanical polishing pad and the substrate; and dispersing the a chemical mechanical polishing composition on the abrasive surface of the chemical mechanical polishing pad at or adjacent to an interface between the chemical mechanical polishing pad and the substrate; wherein the at least a portion of the tungsten (W) and at least a portion of the titanium Ti), which is removed by grinding from the substrate; and the chemical mechanical polishing composition provided therein has a removal rate selectivity of tungsten (W) and titanium (Ti) 100.

The present invention provides a method of polishing a substrate, comprising: providing a substrate, wherein the substrate comprises tungsten (W) and titanium (Ti); providing a chemical mechanical polishing composition comprising, as an initial component: water; 1.75 to 3 wt% of an oxidizing agent, wherein The oxidizing agent is hydrogen peroxide; 50 to 80 ppm by mass of chitosan, wherein the chitosan has a weight average molecular weight distribution of 150,000 to 350,000 Daltons; and 0.2 to 2% by weight of a colloidal body with a constant positive surface charge a cerium oxide abrasive; 900 to 1,100 ppm by mass of a dicarboxylic acid, wherein the dicarboxylic acid is malonic acid; and 250 to 400 ppm by mass of an iron (III) ion source, wherein the iron (III) ion source is ferric nitrate; And optionally, a pH adjusting agent; and wherein the chemical mechanical polishing composition has a pH of 2 to 2.5; providing a chemical mechanical polishing pad having an abrasive surface; and dynamically contacting the interface between the chemical mechanical polishing pad and the substrate; And dispersing the chemical mechanical polishing composition on the polishing surface of the chemical mechanical polishing pad at or adjacent to an interface between the chemical mechanical polishing pad and the substrate; wherein the at least a portion of the tungsten (W) and the at least one Sub titanium (Ti), based on the substrate is removed from the polishing; and wherein the chemical mechanical polishing composition provided by removing composition having tungsten (W) and titanium (Ti) of rate selectivity 100.

The method of polishing a substrate of the present invention uses a chemical mechanical polishing composition containing an oxidizing agent; chitosan; a dicarboxylic acid, wherein the dicarboxylic acid The acid is selected from the group consisting of malonic acid and 2-hydroxymalonic acid, and a synergistic composition derived from iron (III) ions. It has been surprisingly found that the synergistic composition can rapidly remove tungsten (W) from the surface during the grinding process while significantly delaying the removal of titanium (Ti).

Preferably, the method of polishing a substrate of the present invention comprises: providing a substrate, wherein the substrate comprises tungsten (W) and titanium (Ti); providing a chemical mechanical polishing composition comprising (preferably consisting of) as an initial component: water (preferably 0.01 to 10% by weight; more preferably 0.1 to 5% by weight; most preferably 1 to 3% by weight) of the oxidizing agent; (preferably 30 to 110 ppm by mass; more preferably 40 to 100 ppm by mass; particularly preferably 45 to 90 ppm by mass) Optimum 50 to 80 ppm by mass of chitosan (preferably wherein the chitosan has a molecular weight of 50,000 to 500,000 Daltons; more preferably 100,000 to 400,000 Daltons; preferably 150,000 to 350,000 Daltons) (preferably 0.01 to 10 wt%; more preferably 0.05 to 7.5 wt%; especially preferably 0.1 to 5 wt%; optimally 0.2 to 2 wt%) of a colloidal ceria abrasive having a constant positive surface charge; (preferably 100 to 1,300 ppm by mass; more preferably 500 to 1,250 ppm by mass; particularly preferably 750 to 1,200 ppm by mass; optimally 900 to 1,100 ppm by mass of the dicarboxylic acid, wherein the dicarboxylic acid is selected from the group consisting of malonic acid and 2-hydroxypropyl a group of diacid compositions (preferably malonic acid); (preferably 100 to 1,000 ppm by mass; more preferably 150 to 750 ppm by mass; particularly preferably 200 to 500 ppm by mass; most preferably 250 to 400 ppm by mass) An iron (III) ion source (preferably wherein the iron (III) ion source is ferric nitrate nonahydrate); and optionally, a pH adjuster; (preferably wherein the chemical mechanical polishing composition has a pH of 1 to 6; more preferably 1 to 4; especially preferably 1.5 to 3.5; optimally 2 to 2.5); providing a chemical mechanical polishing pad having an abrasive surface; generating dynamic contact at an interface between the chemical mechanical polishing pad and the substrate; a chemical mechanical polishing composition on the polishing surface of the chemical mechanical polishing pad at or adjacent to an interface between the chemical mechanical polishing pad and the substrate; wherein the at least a portion of the tungsten (W) and at least a portion of the titanium (Ti) Grinding removal from the substrate; and the chemical mechanical polishing composition provided therein has a removal rate selectivity of tungsten (W) and titanium (Ti) 100.

Preferably, in the method of polishing a substrate of the present invention, the substrate comprises tungsten and titanium. More preferably, the substrate provided is a semiconductor substrate comprising tungsten and titanium. Most preferably, the substrate provided is a semiconductor substrate comprising tungsten deposited in at least one of the holes and trenches in the dielectric (e.g., TEOS), wherein titanium is deposited between the tungsten and the dielectric.

Preferably, in the method of polishing a substrate of the present invention, the water contained in the chemical mechanical polishing composition, as an initial component, is at least one of deionized water and distilled water to limit incidental impurities.

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising an oxidizing agent, wherein the oxidizing agent is hydrogen peroxide (H ₂ O ₂ ), monopersulfate, iodic acid. Salt, magnesium perphthalate, peracetic acid and other peroxyacids, persulfates, bromates, perbromates, persulfates, peracetic acid, periodate, nitrates, iron salts, barium salts a group consisting of Mn(III), Mn(IV) and Mn(VI) salts, silver salts, copper salts, chromium salts, cobalt salts, halogens, hypochlorites, and mixtures thereof. More preferably, the oxidizing agent is selected from the group consisting of hydrogen peroxide, perchlorate, perbromate; periodate, persulphate and peracetic acid. Most preferably the oxidizing agent is hydrogen peroxide.

Preferably, in the method of polishing a substrate of the present invention, The chemical mechanical polishing composition is provided as an initial component comprising 0.01 to 10% by weight (more preferably 0.1 to 5% by weight; most preferably 1 to 3% by weight) of an oxidizing agent.

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising a source of iron (III) ions. More preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising an iron (III) ion source, wherein the source of the iron (III) ion is selected from iron (III) a group of salts. Most preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising an iron (III) ion source, wherein the iron (III) ion source is ferric nitrate nonahydrate (Fe) (NO ₃ ) ₃ ‧9H ₂ O).

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising a source of iron (III) ions sufficient to introduce 1 to 200 ppm by mass (preferably 5 to 150 ppm by mass). More preferably 7.5 to 125 ppm by mass; optimally 10 to 100 ppm by mass of iron (III) ions are added to the chemical mechanical polishing composition.

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising a source of iron (III) ions. More preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component, and comprises 100 to 1,000 ppm by mass (preferably 150 to 750 ppm by mass; more preferably 200 to 500 ppm by mass; most A good source of iron (III) ions of 250 to 400 mass ppm. Most preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component, comprising 100 to 1,000 ppm by mass (preferably 150 to 750 ppm by mass; more preferably 200 to 500 ppm by mass; most Preferably, the source of iron (III) ions is from 250 to 400 mass ppm, wherein the source of iron (III) ions is iron nitrate nonahydrate (Fe(NO ₃ ) ₃ ‧9H ₂ O).

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising chitosan. More preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising a weight average molecular weight of 50,000 to 500,000 Daltons (more preferably 100,000 to 400,000 Daltons; preferably 150,000) Chitosan to 350,000 Daltons.

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component, comprising 5 to 300 ppm by mass (preferably 30 to 110 ppm; more preferably 40 to 100 ppm by mass; particularly preferably 45) Up to 90 ppm by mass; optimally 50 to 80 ppm by mass of chitosan. More preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component, and contains 5 to 300 ppm by mass (preferably 30 to 110 ppm; more preferably 40 to 100 ppm by mass; particularly preferably 45) Up to 90 ppm by mass; optimally 50 to 80 ppm by mass of chitosan, wherein the chitosan has a weight average molecular weight of 50,000 to 500,000 Daltons (more preferably 100,000 to 400,000 Daltons; optimally 150,000 to 350,000) Dalton). Most preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising 50 to 80 ppm by mass of chitosan, wherein the chitosan has a weight average molecular weight of 150,000 to 350,000 Daltons.

Preferably, in the method of polishing a substrate of the present invention, The chemical mechanical polishing composition is provided as an initial component comprising a colloidal ceria abrasive having a constant positive surface charge. More preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising a colloidal ceria abrasive having a constant positive surface charge, wherein the chemical mechanical polishing composition has pH 1 To 6 (preferably 1 to 4; more preferably 1.5 to 3.5; especially preferably 1.75 to 3; optimum 2 to 2.5). More preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising a colloidal ceria abrasive having a constant positive surface charge, wherein the chemical mechanical polishing composition has a pH 1 to 6 (preferably 1 to 4; more preferably 1.5 to 3.5; particularly preferably 1.75 to 3; optimum 2 to 2.5), with zeta potential > 1 mV as an index.

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising a colloidal ceria abrasive having a constant positive surface charge, wherein the colloidal ceria abrasive article has an average Particle size 100 nm (preferably 5 to 100 nm; more preferably 10 to 60 nm; optimally 20 to 60 nm) is measured by dynamic light scattering technique.

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component, comprising 0.01 to 10% by weight (preferably 0.05 to 7.5 wt%; more preferably 0.1 to 5 wt%; optimum 0.2) Up to 2% by weight of a colloidal ceria abrasive with a constant positive surface charge.

The term "constant positive surface charge" as used herein means that the positive charge on the cerium oxide particles is not easily reversed. That is, the positive charge on the cerium oxide particles is not reversed by rinsing, dilution or filtration. Constant positive charge can be, for example, a cationic species covalently bonded to colloidal oxygen The result on the bismuth particles. The colloidal cerium oxide with a constant positive surface charge is a colloidal cerium oxide which can easily reverse the positive surface charge as a result of electrostatic interaction between the cationic species and the colloidal cerium oxide particles.

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising a dicarboxylic acid, wherein the dicarboxylic acid is selected from the group consisting of malonic acid (also known as malic acid) Malonic acid)) is a group consisting of 2-hydroxymalonic acid (also known as tartronic acid). More preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component comprising a dicarboxylic acid, wherein the dicarboxylic acid is malonic acid.

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component, and comprises 1 to 2,600 ppm by mass (preferably 100 to 1,300 ppm by mass; more preferably 500 to 1,250 ppm by mass; Preferably, it is 750 to 1,200 ppm by mass; preferably 900 to 1,100 ppm by mass of the dicarboxylic acid, wherein the dicarboxylic acid is selected from the group consisting of malonic acid and 2-hydroxymalonic acid. More preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided as an initial component, and comprises 1 to 2,600 ppm by mass (preferably 100 to 1,300 ppm by mass; more preferably 500 to 1,250 ppm by mass; Preferably, 750 to 1,200 ppm by mass; optimally 900 to 1,100 ppm by mass of the dicarboxylic acid, wherein the dicarboxylic acid is malonic acid.

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided at a pH of from 1 to 6. More preferably, in the method of polishing a substrate of the present invention, the provided chemical mechanical polishing composition has pH 1 to 4. More preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided at a pH of from 1.5 to 3.5. Most preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition is provided at a pH of from 2.0 to 2.5.

Preferably, in the method of polishing a substrate of the present invention, the provided chemical mechanical polishing composition selectively comprises a pH adjuster. Preferably, the pH adjusting agent is selected from the group consisting of inorganic and organic pH adjusting agents. Preferably, the pH adjusting agent is selected from the group consisting of inorganic acids and inorganic bases. More preferably, the pH adjusting agent is selected from the group consisting of nitric acid and potassium hydroxide. Most preferably, the pH adjusting agent is potassium hydroxide.

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing pad provided may be any suitable polishing pad known in the art. Those skilled in the art will be able to select a chemical mechanical polishing pad suitable for use in the method of the present invention. More preferably, in the method of polishing a substrate of the present invention, the provided chemical mechanical polishing pad may be selected from the group consisting of woven and non-woven abrasive pads. More preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing pad provided comprises a polyurethane abrasive layer. Most preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing pad provided comprises a polyurethane abrasive layer comprising polymerizable hollow particles, and a non-woven sub-pad impregnated with polyurethane. Preferably, the CMP pad is provided with at least one groove on the abrasive surface.

Preferably, in the method of polishing a substrate of the present invention, the provided chemical mechanical polishing composition is interspersed on the abrasive surface of the chemical mechanical polishing pad at or adjacent to the interface between the chemical mechanical polishing pad and the substrate.

Preferably, in the method of polishing a substrate of the present invention, the dynamic contact is provided at the interface between the chemical mechanical polishing pad and the substrate, and is performed at a pressure of 0.69 to 34.5 kPa orthogonal to the surface of the substrate to be polished.

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition provided therein has a tungsten removal rate 500Å/min (better 1,000Å/min; 1,500 Å / min; best 2,000 Å/min). More preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition provided therein has a tungsten removal rate 1,000Å/min (better 1,500 Å / min; best 2,000 Å/min). More preferably, in the method of polishing a substrate of the present invention, in the method of polishing a substrate of the present invention, wherein tungsten is removed at a rate 1,000Å/min (better 1,500 Å / min; best 2,000 Å/min) is removed from the substrate. Most preferably, in the method of polishing a substrate of the present invention, wherein tungsten is removed at a rate 1,000Å/min (better 1,500 Å / min; best 2,000 Å/min) removed from the substrate; and the chemical mechanical polishing composition provided therein has a tungsten removal rate 1,000Å/min (better 1,500 Å / min; best 2,000 Å/min), wherein the platen speed is 80 rpm, the carrier speed is 81 rpm, the chemical mechanical polishing composition has a flow rate of 125 mL/min, and the downforce is 21.4 kPa on a 200 mm grinding machine; The chemical mechanical polishing pad comprises a polyurethane abrasive layer comprising polymeric hollow particles and a non-woven sub-pad impregnated with polyurethane.

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition provided therein has a titanium (Ti) removal rate 100 Å/min (better 50Å/min; best 25Å/min). More preferably, in the method of polishing a substrate of the present invention, wherein titanium (Ti) is removed at a rate 100Å/min (better 50Å/min; best 25Å/min) removed from the substrate. Most preferably, in the method of polishing a substrate of the present invention, wherein titanium (Ti) is removed at a rate 100Å/min (better 50Å/min; best 25Å/min) removed from the substrate; and wherein the chemical mechanical polishing composition has a titanium (Ti) removal rate 100Å/min (better 50Å/min; best 25Å/min), wherein the platen speed is 80 rpm, the carrier speed is 81 rpm, the chemical mechanical polishing composition has a flow rate of 125 mL/min, and the downforce is 21.4 kPa on a 200 mm grinding machine; The chemical mechanical polishing pad comprises a polyurethane abrasive layer comprising polymeric hollow particles and a non-woven sub-pad impregnated with polyurethane.

Preferably, in the method of polishing a substrate of the present invention, the chemical mechanical polishing composition provided has a tungsten (W) removal rate. 500Å/min (better 1,000Å/min; 1,500 Å / min; best 2,000 Å/min) and titanium removal rate 100Å/min. More preferably, in the method of polishing a substrate of the present invention, the substrate provided comprises tungsten (W) and titanium; wherein the tungsten (W) is removed at a rate 1,500 Å/min removed from the substrate, and titanium (Ti) removed at a rate 100Å/min (better 50Å/min; best 25Å/min) removed from the substrate. Most preferably, in the method of polishing a substrate of the present invention, the substrate provided comprises tungsten (W) and titanium (Ti); wherein the tungsten (W) is removed at a rate 1,000Å/min (better 1,500 Å / min; best 2,000 Å/min) removed from the substrate; titanium (Ti) at removal rate 100Å/min (better 50Å/min; best 25Å/min) removed from the substrate; and the chemical mechanical polishing composition provided therein has tungsten (W) to titanium (Ti) removal rate selectivity (W/Ti selectivity) 100 (better 150; better 200; best 300) wherein the platen rotation speed is 80 rpm, the carrier rotation speed is 81 rpm, the chemical mechanical polishing composition has a flow rate of 125 mL/min, and the lower pressure is 21.4 kPa on the 200 mm grinding machine; and wherein the chemical mechanical polishing The mat comprises a polyurethane abrasive layer comprising polymerizable hollow particles and a non-woven sub-pad impregnated with polyurethane.

Certain embodiments of the invention are described in detail in the following examples .

Comparative Examples C1-C5 and Examples 1-8 Preparation of chemical mechanical polishing composition

The chemical mechanical polishing compositions of Comparative Examples C1-C5 and Examples 1-8 were combined with the components and amounts listed in Table 1 , and equilibrated with deionized water, and the pH of the composition was adjusted with potassium hydroxide or nitric acid. Prepared by the final pH values listed in Table 1 .

Comparative example PC1-PC5 and examples P1-P8 Chemical mechanical polishing removal rate experiment

The removal rate grinding test was carried out in Comparative Examples PC1-PC5 and Examples P1-P8 , using the chemical mechanical polishing compositions prepared in Comparative Examples C1-C5 and Examples 1-8 , respectively. The grinding removal rate experiments were performed on 200 mm blanket wafers mounted on an Applied Materials 200mm Mirra® grinding machine. The polishing removal rate test was performed on a 200 mm tungsten (W) felt coated wafer from SEMATECH SVTC, and a titanium (Ti) felt coated wafer, which was obtained from SEMATECH SVTC. All milling experiments using IC1010 ^TM-based polyurethane-polishing pad, with the sub pad has SP2310 (available from Rohm and Haas Electronic Materials CMP Inc.) carried out under a pressure of 21.4kPa (3.1psi), a chemical mechanical polishing composition of The flow rate was 125 mL/min, the table rotation speed was 80 rpm, and the carrier rotation speed was 81 rpm, and the polishing cycle was 60 seconds. Diamond Abrasive Pad Dresser PDA33A-D (available from Kinik Company) is used to trim the polishing pad. The polishing pad was broken in the dresser, using a trimming pressure of 9 lbs (4.1 kg) for 15 minutes, followed by a trimming pressure of 7 lbs (3.18 kg) for 15 minutes. Between each grinding experiment, the polishing pad was further transposed before grinding, using a downforce of 7 lbs (3.18 kg) for 24 seconds. The removal rates of tungsten (W) and titanium (Ti) were determined using a Jordan Valley JVX-5200T metrology tool. The results of the removal rate experiments are provided in Table 2.

Claims (10)

A method of polishing a substrate, comprising: providing the substrate, wherein the substrate comprises tungsten (W) and titanium (Ti); providing a chemical mechanical polishing composition comprising: as an initial component: water; an oxidant; chitosan; a colloidal ceria abrasive having a constant surface charge; a dicarboxylic acid, wherein the dicarboxylic acid is selected from the group consisting of malonic acid and 2-hydroxymalonic acid; an iron (III) ion source; and a selectivity a pH adjusting agent; providing a chemical mechanical polishing pad having an abrasive surface; generating a dynamic contact at an interface between the chemical mechanical polishing pad and the substrate; and dispersing the chemical mechanical polishing composition on the polishing surface of the chemical mechanical polishing pad And at least adjacent to the interface between the chemical mechanical polishing pad and the substrate; wherein at least a portion of the tungsten (W) and at least a portion of the titanium (Ti) are removed from the substrate; and wherein The chemical mechanical polishing composition has a removal rate selectivity between tungsten (W) and titanium (Ti) 100. The method of claim 1, wherein the chemical mechanical polishing composition is provided with a tungsten removal rate 1,000 Å/min, wherein the platen speed is 80 rpm, the carrier speed is 81 rpm, the chemical mechanical polishing composition has a flow rate of 125 mL/min, and the downforce is 21.4 kPa on a 200 mm grinding machine; The CMP pad comprises a polyurethane abrasive layer comprising polymeric hollow particles and a non-woven sub-pad impregnated with polyurethane. The method of claim 2, wherein the chemical mechanical polishing composition provided has a titanium removal rate 50Å/min, and the removal rate selectivity of tungsten (W) and titanium (Ti) 100. The method of claim 1, wherein the chemical mechanical polishing composition is provided as an initial component: the water; 0.01 to 10% by weight of the oxidizing agent, wherein the oxidizing agent is hydrogen peroxide; 30 to 110 a mass ppm of the chitosan, wherein the chitosan has a weight average molecular weight distribution of 50,000 to 500,000 Daltons; 0.01 to 10% by weight of the colloidal ceria abrasive; 100 to 1,300 ppm by mass of the dicarboxylic acid An acid, wherein the dicarboxylic acid is malonic acid; 100 to 1,000 ppm by mass of the iron (III) ion source, wherein the iron (III) ion source is ferric nitrate nonahydrate; and optionally, the pH adjuster And wherein the chemical mechanical polishing composition has a pH of 1 to 4. The method of claim 4, wherein the chemical mechanical polishing composition is provided with a tungsten removal rate 1,500 Å/min, wherein the platen speed is 80 rpm, the carrier speed is 81 rpm, the chemical mechanical polishing composition has a flow rate of 125 mL/min, and the downforce is 21.4 kPa on a 200 mm grinding machine; The CMP pad comprises a polyurethane abrasive layer comprising polymeric hollow particles and a non-woven sub-pad impregnated with polyurethane. The method of claim 5, wherein the chemical mechanical polishing composition is provided with a titanium removal rate 50Å/min, and removal rate selectivity of tungsten (W) and titanium (Ti) 100. The method of claim 1, wherein the chemical mechanical polishing composition is provided as an initial component: the water; 1.75 to 3% by weight of the oxidizing agent, wherein the oxidizing agent is hydrogen peroxide; 50 to 80 a mass ppm of the chitosan, wherein the chitosan has a weight average molecular weight distribution of 150,000 to 350,000 Daltons; 0.2 to 2 wt% of the colloidal ceria abrasive; 900 to 1,100 ppm by mass of the dicarboxylic acid An acid, wherein the dicarboxylic acid is malonic acid; 250 to 400 ppm by mass of the iron (III) ion source, wherein the iron (III) ion source is ferric nitrate; and optionally, the pH adjuster; The chemical mechanical polishing composition has a pH of 2 to 2.5. The method of claim 7, wherein the chemical mechanical polishing composition is provided with a tungsten removal rate 2,000 Å/min, wherein the platen speed is 80 rpm, the carrier speed is 81 rpm, the chemical mechanical polishing composition has a flow rate of 125 mL/min, and the downforce is 21.4 kPa on a 200 mm grinding machine; The CMP pad comprises a polyurethane abrasive layer comprising polymeric hollow particles and a non-woven sub-pad impregnated with polyurethane. The method of claim 8, wherein the chemical mechanical polishing composition is provided with a titanium removal rate 25Å/min, and removal rate selectivity of tungsten (W) and titanium (Ti) 200. The method of claim 8, wherein the chemical mechanical polishing composition is provided with a titanium removal rate 25Å/min, and removal rate selectivity of tungsten (W) and titanium (Ti) 300.