JP2006049912A - Cmp slurry, chemical mechanical polishing method using the cmp slurry, and method of forming metal wiring using the cmp slurry - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a CMP slurry, a CMP that uses the CMP slurry, and a method of forming metal wiring that uses the CMP slurry. <P>SOLUTION: The CMP slurry contains a polishing agent, an oxidant, and at least one defect inhibitor to protect the metal film. By using the CMP slurry in the CMP and the formation of the metal wiring, defects formed on the surface of the metal film can be decreased, or protected, and reliable metal wiring can be formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a CMP slurry, a chemical mechanical polishing method using the CMP slurry, and a metal wiring forming method using the CMP slurry.

  Aluminum including an aluminum alloy is one of conductive materials used as a wiring or a plug in a semiconductor device. Here, an aluminum alloy is defined to include any composition in which aluminum is the main component.

  Conventionally, an aluminum thin film is deposited using sputtering or chemical vapor deposition (CVD), and an aluminum pattern is formed by etching a thin aluminum film using reactive ion etching (RIE). . The conventional RIE method has a drawback in that the connection between the aluminum patterns and / or the generation of voids in the aluminum pattern is caused due to thermal stress.

  Recently, a damascene process has been widely used to form aluminum wiring. The conventional damascene process is a process in which interconnected metal lines are separated from each other by an insulator by chemical mechanical planarization or chemical mechanical polishing (CMP). In a conventional damascene process, an interconnect pattern is formed by photolithography in an insulating layer and a metal is deposited so that the metal fills the pattern trenches and the excess metal is removed by CMP. A conventional damascene process for forming a metal wiring such as an aluminum wiring or a copper wiring is shown in FIGS.

  As shown in FIG. 1, the conventional damascene process includes a step of forming an intermetallic insulating film (IMD) 12 on the substrate 10 and a patterning of the intermetallic insulating film 12 as shown in FIG. Forming a region 14 where the metal wiring is formed.

  As shown in FIG. 3, the conventional damascene process includes a process of forming a barrier film 16, a process of forming a thick aluminum film 18 on the barrier film 16 as shown in FIG. 4, and a process shown in FIG. As described above, the method further includes a step of removing the aluminum film 18 and the barrier film 16 on the surface of the intermetal insulating film 12 by using a CMP process.

  In the conventional damascene process for forming aluminum wiring described above, the CMP process can affect one or more electrical characteristics of the aluminum wiring. More specifically, the selective removal rate of the CMP slurry can be one factor that affects the electrical characteristics of the aluminum wiring.

  When the selective removal rate of the aluminum film 18 with respect to the silicon oxide film is low like the aluminum film 18 with respect to the IMD layer 12 in FIGS. 1 to 5, the aluminum film 18 is over-etched during the CMP process. Over-etching causes damascene on the surface of the aluminum wiring, which increases the electrical resistance of the aluminum wiring. Therefore, the speed of the electrical signal transmitted through the aluminum wiring of the semiconductor device is reduced, and eventually the overall performance of the semiconductor device is degraded.

  If the selective removal rate with respect to the metal thin film is low like the above-described aluminum film with respect to the silicon oxide film, overetching of the aluminum film is induced and the surface area of the aluminum wiring is reduced. It also increases the electrical resistance of the aluminum wiring and reduces the speed of electrical signals transmitted through the aluminum wiring of the semiconductor device, thereby reducing the overall performance of the semiconductor device.

  Conventionally, a high selective removal rate of the metal thin film relative to the silicon oxide thin film induces scratches, corrosion, and / or dents. The scratch defect is shown in FIG. 6 and is a surface roughness caused by damage caused on the surface of the aluminum film by the abrasive. Although the dent defect on the surface of the aluminum film is shown in FIG. 7, this defect can occur when the scratch is more advanced. Although the corrosion defect is shown in FIG. 8, it shows that aluminum ions are desorbed from the aluminum film by a chemical reaction with other substances.

  The above-mentioned defects are due to the soft properties of metals with relatively low hardness and stress resistance, such as aluminum. Scratches, corrosion, or dents in aluminum not only reduce the refractive index of the metal, but also reduce the reliability of the metal wiring, and at worst, result in the metal wiring being cut. Until now, there has been no CMP slurry that reduces or prevents defects on the surface of such soft metal films.

  Accordingly, an object of the present invention is to provide a CMP slurry capable of forming a highly reliable metal wiring. A further object of the present invention is to provide a CMP using the CMP slurry and a metal wiring forming method using the CMP slurry.

  The first aspect of the present invention is a CMP slurry used in a chemical mechanical polishing (CMP) method for polishing a metal thin film, the CMP slurry protecting an abrasive, an oxidizing agent, and the metal thin film. A CMP slurry comprising at least one defect inhibitor.

  The second aspect of the present invention is a chemical mechanical polishing method for polishing a metal thin film formed on a substrate, comprising an abrasive, an oxidizing agent, and at least one defect preventing agent for protecting the metal thin film. A chemical mechanical polishing method comprising: a step of preparing a CMP slurry; and a step of chemical mechanical polishing the metal thin film using the CMP slurry.

  Further, a third aspect of the present invention is a chemical mechanical polishing method for a metal thin film formed on a substrate, the step of preparing a first slurry containing an abrasive and an oxidizing agent, and using the first slurry. Chemically and mechanically polishing the metal thin film, preparing a second slurry containing an abrasive, an oxidizing agent, and at least one defect preventing agent for protecting the metal thin film, and the second slurry. And chemical mechanical polishing the metal thin film using a chemical mechanical polishing method.

  The present invention relates to a method of forming a metal wiring, which is patterned by forming an intermetal insulating film on a substrate, patterning the intermetallic insulating film to form a region for metal wiring, and the like. A CMP slurry containing a step of forming a barrier film on the intermetal insulating film, a step of forming a metal thin film on the barrier film, an abrasive, an oxidizing agent, and a defect preventing agent for protecting the metal thin film. And using to polish the metal thin film.

  The present invention relates to a method of forming a metal wiring, which includes a step of forming an intermetallic insulating film on a semiconductor substrate, a step of patterning the intermetallic insulating film to form a region for metal wiring, and a patterning Forming a barrier film on the intermetal insulating film formed, forming a metal thin film on the barrier film, and polishing the metal thin film using a first slurry containing an abrasive and an oxidizing agent And polishing the metal thin film using a second slurry containing a polishing agent, an oxidizing agent, and a defect preventing agent for protecting the metal thin film.

  The CMP slurry of the present invention can chemically and mechanically polish aluminum or an aluminum alloy without causing defects such as dents and scratches, so that highly reliable metal wiring can be formed.

  The accompanying figures are merely illustrative of the general characteristics of the methods and devices of embodiments of the present invention. In the drawings, the thickness of layers and regions are exaggerated for clarity. Also, when a layer is referred to as being “on” another layer or substrate, it includes the case where it is formed directly on the other layer or substrate and the intervening third layer therebetween. Throughout the specification, identical reference numbers indicate identical components.

  The present invention provides a CMP slurry for use in a CMP process or metal thin film formation. The CMP slurry provided by the present invention exhibits a high selective removal rate, and this CMP slurry mixture is adsorbed on the surface of a metal thin film such as an aluminum thin film to give a protective film forming function to the metal thin film. It includes compounds thereby reducing or preventing metal surface defect formation such as scratches, dimples, corrosion, dishing, or erosion.

The compound can provide a protective film forming function to the metal thin film by generating an anion. The anion due to the compound can be adsorbed on the surface of the metal thin film having a cation to form a protective film. The compound can also generate cations such as H ⁺ to increase the acidity of the CMP slurry solution.

  In the CMP slurry solution, the degree of adsorption of the compound to the metal thin film decreases as the pH increases. This is because the zeta potential between the metal thin film and the CMP slurry solution decreases as the pH increases.

  FIG. 9 illustratively shows the zeta potential of negatively charged particles. Negatively charged particles have a negative charge on the surface. In solution (eg, water), negatively charged particles are adjacent to a first layer, which is mostly cations, followed by a second layer, which is mostly anions. The first layer and the second layer are ions that cannot move. The further away from the negatively charged particles, the closer the mixed layer of cations and anions to the bulk solution (the mixed layer of cations and anions).

  As shown in FIG. 9, the outer circle is a region in which cations and anions are distributed substantially uniformly.

  The movement of ions to the two nuclei (Helmholtz double layer) on the particle surface is very limited. Ions lose some of their charge with the particles. After these two nuclei are formed, a slip plane exists. The zeta potential is the difference in charge between the whole liquid and the particles with fixed ions. The zeta potential depends on the ion concentration, pH, viscosity, and the dielectric constant of the solution being analyzed.

  FIG. 10 shows the relationship between pH and zeta potential in an aluminum substrate, a silicon substrate, and a tetraethoxysilane (TEOS) substrate.

The polymer compound having a carboxyl group is a suitable compound that can generate anions adsorbed on the surface of the metal thin film and hydrogen ions that acidify the CMP slurry solution. As shown in FIG. 11, the polymer compound having a carboxyl group is dissociated into a carboxylate anion COO ⁻ and a hydrogen ion H ⁺ in the CMP slurry solution. Carboxylic acid anions adsorb to the aluminum film 18 to form a protective film, and hydrogen ions acidify the CMP slurry solution.

  The CMP slurry includes an abrasive, an oxidizing agent, and one or more defect prevention agents, and optionally includes a pH adjusting agent. The abrasive is preferably one or more substances selected from the group consisting of ceria, silica, fumed silica, alumina, titania, zirconia, and germanium oxide. The abrasive content is preferably in the range of 0.5 wt% to about 20 wt% based on the total weight of the CMP slurry.

The oxidizing agent is hydrogen peroxide (H ₂ O ₂ ), ceric ammonium nitrate ((NH ₄ ) ₂ Ce (NO ₃ ) ₆ ), hydroxylamine (NH ₂ OH), or ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ) is preferred, and hydrogen peroxide is more preferred. The content of the oxidizing agent is preferably in the range of about 0.5 wt% to about 5 wt% based on the total weight of the CMP slurry.

  The pH adjuster is at least one base selected from the group consisting of potassium hydroxide, ammonium hydroxide, sodium hydroxide, tetramethylammonium hydroxide (TMAH), and choline, or sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, At least one acid selected from the group consisting of succinic acid, tartaric acid, and acetic acid is preferred. In an embodiment of the present invention, the pH of the CMP slurry solution is in the acidic region. This is because the zeta potential is positive in the acidic region. The pH of the CMP slurry solution is preferably less than 7, and more preferably the pH is 2-4.

  The defect preventing agent is preferably a polymer compound having a carboxyl group. Examples of the polymer compound having a carboxyl group include polyacrylic acid (PAA), polymethacrylic acid, acrylic acid-maleic acid copolymer (PAMA), methacrylic acid-maleic acid copolymer, acrylic acid-acrylamide copolymer. A polymer, an acrylonitrile-butadiene-acrylic acid copolymer, an acrylonitrile-butadiene-methacrylic acid copolymer, a derivative of the polymer compound, or a salt of the polymer compound. More preferred are polyacrylic acid (PAA), acrylic acid-maleic acid copolymer (PAMA), salt of PAA, salt of PAMA, or a mixture thereof, and particularly preferred salt of PAA or salt of PAMA It is. The defect inhibitor can lower the pH of the CMP slurry solution, have hydrogen ions, and / or reduce scratches, corrosion, dents, dishing, or erosion of the metal film surface.

  The CMP slurry of the present invention may preferably contain 0.01 to 20% by weight of a chelating agent. As chelating agents, ethylenediaminetetraacetic acid (EDTA), cyclohexanediaminetetraacetic acid (CyDTA), nitrilotriacetic acid (NTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), triethylenetetraminehexaacetic acid (TTHA) ), L-glutamic acid diacetic acid (GLDA), aminotrimethylenephosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetrakis (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), β-alanine diacetic acid (Β-ADA), α-alanine diacetate (α-ADA), L-aspartate diacetate (ASDA), ethylenediamine disuccinate (EDDS), iminodiacetic acid (IDA), N- (2-hydroxyethyl) ) At least one compound selected from the group consisting of iminodiacetic acid (HEIDA) and 1,3-propanediaminetetraacetic acid (1,3-PDTA) is preferable, and salts of the chelating agents exemplified above are also preferable. .

  The defect preventing agent can form a protective film on the surface of the metal thin film and can be adsorbed on the surface of the metal thin film.

  In an embodiment, the amount of one of the defect inhibitors may be about 0.01 to 20% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of one of the defect inhibitors may be about 0.01 to 10% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of one of the defect inhibitors may be about 10 to 20% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of one of the defect inhibitors may be about 0.01 to 50% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of one of the defect inhibitors may be about 5 to 10% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of one of the defect inhibitors may be about 10 to 15% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of one of the defect inhibitors may be about 15 to 20% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of one of the defect inhibitors may be about 0.01 to 3% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of one of the defect inhibitors may be about 0.01 to 1% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of one of the defect inhibitors may be about 0.01 to 0.5% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of one of the defect inhibitors may be about 0.01 to 0.1% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of one of the defect inhibitors may be about 0.01 to 0.05% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of one of the defect inhibitors may be about 0.1 to 0.5% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of one of the defect inhibitors may be about 0.2 to 0.3% by weight based on the total weight of the CMP slurry.

  In another embodiment, the other defect preventing agent may be a chelating agent. In an embodiment, the amount of the chelating agent may be about 0.01 to 20% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of the chelating agent may be about 0.01 to 10% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of the chelating agent may be about 10 to 20% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of the chelating agent may be about 0.01 to 5% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of the chelating agent may be about 5 to 10% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of the chelating agent may be about 10 to 15% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of the chelating agent may be about 15 to 20% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of the chelating agent may be about 0.01 to 3% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of the chelating agent may be about 0.01 to 1% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of the chelating agent may be about 0.01 to 0.5% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of the chelating agent may be about 0.01 to 0.3% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of the chelating agent may be about 0.01 to 0.2% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of the chelating agent may be about 0.05 to 0.15% by weight based on the total weight of the CMP slurry. In an embodiment, the amount of the chelating agent may be about 0.02 to 0.3% by weight based on the total weight of the CMP slurry.

  In an embodiment, the chelating agent is ethylenediaminetetraacetic acid (EDTA), cyclohexanediaminetetraacetic acid (CyDTA), nitrilotriacetic acid (NTA), hydroxylethylethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), triethylenetetramine hexa Acetic acid (TTHA), L-glutamic acid diacetic acid (GLDA), aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetrakis (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), β -Alanine diacetate (β-ADA), α-alanine diacetate (α-ADA), aspartate diacetate (ASDA), ethylenediamine succinate (EDDS), iminodiacetic acid IDA, hydroxyl ethyl Iminoni acetate (HEIDA), 1,3-propanediamine tetraacetic acid 1, 3-PDTA, salts thereof, and at least one compound selected from the group consisting of mixtures thereof are preferred.

  In embodiments, the amount of abrasive is preferably about 0.5-20% by weight based on the total weight of the CMP slurry. In an embodiment, the abrasive is preferably at least one selected from the group consisting of ceria, silica, alumina, titania, zirconia, and germanium oxide.

In embodiments, the amount of oxidant is preferably about 0.5-5% by weight based on the total weight of the CMP slurry. In an embodiment, the oxidizing agent is hydrogen peroxide (H ₂ O ₂ ), ceric ammonium nitrate ((NH ₄ ) ₂ Ce (NO ₃ ) ₆ ), hydroxylamine (NH ₂ OH), and ammonium persulfate ((NH ₄ ) At least one selected from the group consisting of ₂ S ₂ O ₈ ) is preferable.

  In an embodiment, the pH adjuster adjusts the pH of the CMP slurry. In embodiments, the pH adjuster comprises at least one of sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, succinic acid, tartaric acid, and acetic acid. In an embodiment, the pH adjuster lowers the pH of the CMP slurry and increases the zeta potential between the metal film and the CMP slurry.

  The metal thin film is preferably aluminum, an aluminum alloy, copper, or a copper alloy. The metal thin film can be used to form a metal wiring or a metal plug.

  About 10% by weight colloidal silica, 1% by weight hydrogen peroxide, 0.1% by weight EDTA, and 0.25% by weight PEI (polyethyleneimine) to test the effectiveness of defect inhibitors with carboxyl groups A CMP slurry according to the present invention comprising about 10 wt% colloidal silica, 1 wt% hydrogen peroxide, 0.1 wt% EDTA, and 0.25 wt% PAMA Used for CMP process. The results for the first device FN73 are shown in FIGS. 12A and 12B, and the results for the second device L13 are shown in FIGS. 13A and 13B.

  To test the effectiveness of a defect inhibitor with a chelating agent, about 10 wt% colloidal silica, 1 wt% hydrogen peroxide, 0.25 wt% polyethyleneimine (PEI), and 0.1 wt% EDTA A CMP slurry according to one embodiment of the present invention comprising about 10 wt% colloidal silica, 1 wt% hydrogen peroxide, and 0.25 wt% PAMA, and about 10 wt% CMP of aluminum is performed using a CMP slurry according to another embodiment of the present invention comprising colloidal silica, 1 wt% hydrogen peroxide, 0.25 wt% PAMA, and 0.1 wt% EDTA. The obtained results are shown in FIGS. 14, 15, and 16, respectively.

  From the test results shown in FIGS. 14 to 16, it is confirmed that the CMP slurry of the present invention containing PAMA as a defect preventing agent has fewer defects overall than the conventional CMP slurry containing PEI and EDTA. it can. The CMP slurry of the present invention containing PAMA and DETA can confirm that the number of defects is reduced and the number of scratch defects is reduced at the same time as the conventional CMP slurry containing PEI and DETA. . Therefore, defects generated when forming the metal wiring by the CMP process can be further reduced by simultaneously using the first defect preventing agent such as PAMA and the second defect preventing agent such as EDTA. .

  Embodiments of the present invention can reduce defects such as scratches, dimples, corrosion, dishing, and / or erosion by forming a protective film on the surface of the metal thin film and / or reducing the removal rate of the metal thin film. It prevents it from occurring on the surface of the thin film.

  The CMP slurry according to the present invention can be used to polish the surface of a metal thin film such that the metal wiring is held in a damascene pattern, thereby exposing the surface of the intermetallic insulating layer. As shown in FIG. 17, in the CMP process of the present invention, a CMP slurry containing an abrasive, an oxidizing agent, and a defect prevention agent is prepared as described above (1004), and the CMP slurry is used. A step of performing CMP (1006).

  In one embodiment, the selective removal ratio of the CMP slurry to the metal thin film may be 20: 1 to 1: 1. In other embodiments, the selective removal rate of the CMP slurry relative to the metal film can be 17: 1 to 1.5: 1.

  In another embodiment, the CMP slurry according to the present invention includes a first polishing step for polishing the surface of the metal thin film so that the metal wiring is held in the damascene pattern after the first CMP process using the first slurry proceeds. Can be used as two slurries, thereby exposing the surface of the intermetallic insulating layer. As shown in FIG. 18, an exemplary CMP process according to the present invention includes a process of preparing a first slurry containing an abrasive and an oxidizing agent (1000), and a process of performing CMP using the first slurry ( 1002), a step (1004) of preparing a second slurry containing an abrasive, an oxidizing agent, and a defect preventing agent, and a step of performing CMP using the second slurry (1006).

  The selective removal rate of the first slurry is preferably larger than the selective removal rate of the second slurry. The selective removal rate of the first slurry is preferably 50: 1 or more. In one embodiment, the selective removal rate of the second slurry can be 20: 1 to 1: 1. In other embodiments, the selective removal rate of the second slurry can be 17: 1 to 1.5: 1.

  19-21 is a figure explaining the CMP process by this invention using the 1st slurry and 2nd slurry which were demonstrated above. As shown in FIG. 19, an intermetallic film 12 is formed on a substrate 10, and the intermetallic insulating film 12 is patterned to form a region 14 for metal wiring. A barrier film 16 is formed on the intermetal insulating film 12, and an aluminum film 18 is formed on the barrier film 16. As shown in FIG. 20, the first CMP process for the aluminum film is performed using the first slurry containing the abrasive and the oxidizing agent. As shown in FIG. 21, a second CMP process is performed using a second slurry containing an abrasive, an oxidizing agent, and a defect preventing agent.

  The CMP slurry according to the present invention can be used to form metal wiring. As shown in FIG. 22, the method for forming a metal wiring according to an embodiment of the present invention includes a step of forming an intermetallic insulating film (1100), a step of patterning the intermetallic insulating film (1102), and forming a barrier film. A step (1104) of forming a metal thin film (1106), and a step (1110) of performing CMP using a CMP slurry containing an abrasive, an oxidizing agent, and a defect preventing agent.

  Preferably, the intermetal insulating film is any one selected from the group consisting of a silicon oxide film, a silicon nitride film, and a combination thereof. The metal thin film is preferably formed by sputtering or CVD.

  In another embodiment, the selective removal rate of the CMP slurry may be 20: 1 to 1: 1. In another embodiment, the selective removal rate of the CMP slurry may be 17: 1 to 1.5: 1.

  In another embodiment, the CMP according to the present invention includes a second slurry for polishing the surface of the metal thin film so that the metal wiring is held in the damascene pattern after the first CMP process using the first slurry. It can also be used for the second CMP step used, whereby the surface of the intermetallic insulating film is exposed. As shown in FIG. 23, the exemplary CMP process according to the present invention includes an intermetallic insulating film forming process (1100), an intermetallic insulating film patterning process (1102), and a barrier film forming process. (1104), a step (1106) of forming a metal thin film, a first CMP step (1108) of polishing the metal thin film using a first slurry containing an oxidizing agent and an abrasive, and an abrasive, an oxidizing agent, And a second CMP step (1110) of polishing the metal thin film using the second slurry containing the defect preventing agent.

  Preferably, the intermetal insulating film is any one selected from the group consisting of a silicon oxide film, a silicon nitride film, and a combination thereof. The metal thin film is preferably formed by sputtering or CVD.

  The selective removal rate of the first slurry is preferably larger than the selective removal rate of the second slurry. The selective removal rate of the first slurry is preferably 50: 1 or more. In one embodiment, the selective removal rate of the second slurry can be 20: 1 to 1: 1. In other embodiments, the selective removal rate of the second slurry can be 17: 1 to 1.5: 1.

  Defects such as scratches, corrosion, and indentations that occur during the first CMP step can be removed during the second CMP step.

  In the above-described embodiments of the present invention, a polymer containing a carboxyl group has been described as an example. However, anions that can be adsorbed on a metal surface and / or hydrogen ions that can acidify a CMP slurry solution can be generated. Any compound can be used.

  Although the embodiments of the present invention described above describe PAA, PAMA, their salts, and mixtures thereof, acidify negative ions and / or CMP slurries that have carboxyl groups and can be adsorbed on metal surfaces. Any mixture capable of generating hydrogen ions that can be generated can be used.

  Although the present invention has been described and described in detail according to the exemplary embodiments, details of the form and details have been described without departing from the technical idea and scope of the present invention defined in the claims. It will be appreciated by those skilled in the art that various changes can be made.

It is process drawing explaining the conventional damascene process. It is process drawing explaining the conventional damascene process. It is process drawing explaining the conventional damascene process. It is process drawing explaining the conventional damascene process. It is process drawing explaining the conventional damascene process. It is a photograph which shows the scratch of the aluminum thin film surface grind | polished with the conventional CMP slurry. It is a photograph which shows the hollow of the aluminum thin film surface grind | polished with the conventional CMP slurry. It is a photograph which shows the corrosion of the aluminum thin film surface grind | polished with the conventional CMP slurry. It is a figure explaining the zeta potential of the negatively charged particles. It is the figure which showed the relationship between pH and a zeta potential in an aluminum substrate, a silicon substrate, and a TEOS substrate. It is a figure explaining that a high molecular compound adsorb | sucks to the metal layer surface, and dissociates into the anion which forms a protective film, and the cation which acidifies a CMP slurry. It is a virtual scanning electron microscope (vSEM) photograph which shows the aluminum thin film surface of the 1st device after the CMP process using the conventional CMP slurry. It is a vSEM photograph which shows the aluminum thin film surface of the 1st device after the CMP process using the CMP slurry by this invention. It is a vSEM photograph which shows the aluminum thin film surface of the 2nd device after the CMP process using the conventional CMP slurry. It is a vSEM photograph which shows the aluminum thin film surface of the 2nd device after the CMP process using the CMP slurry by this invention. FIG. 5 is a diagram illustrating metal wiring formation using a conventional CMP slurry and two CMP slurries according to the present invention. FIG. 5 is a diagram illustrating metal wiring formation using a conventional CMP slurry and two CMP slurries according to the present invention. FIG. 5 is a diagram illustrating metal wiring formation using a conventional CMP slurry and two CMP slurries according to the present invention. It is process drawing explaining CMP using the CMP slurry of this invention containing an abrasive | polishing agent, an oxidizing agent, and a defect prevention agent. It is process drawing explaining CMP of this invention using the 1st slurry containing an abrasive | polishing agent and an oxidizing agent, and the 2nd slurry containing an abrasive | polishing agent, an oxidizing agent, and a defect prevention agent. FIG. 4 is a process diagram illustrating a method for forming a metal thin film by polishing using two CMP slurries, according to an embodiment of the present invention. FIG. 4 is a process diagram illustrating a method for forming a metal thin film by polishing using two CMP slurries, according to an embodiment of the present invention. FIG. 4 is a process diagram illustrating a method for forming a metal thin film by polishing using two CMP slurries, according to an embodiment of the present invention. It is process drawing explaining the formation method of the metal wiring of this invention using the CMP slurry of this invention containing an abrasive | polishing agent, an oxidizing agent, and a defect prevention agent. It is process drawing explaining the formation method of the metal wiring of this invention using the 1st slurry containing an abrasive | polishing agent and an oxidizing agent, and the 2nd slurry containing an abrasive | polishing agent, an oxidizing agent, and a defect prevention agent.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Board | substrate 12 Intermetal insulating film 14 Area | region for metal wiring 16 Barrier film 18 Aluminum film

Claims (68)

A CMP slurry used in a chemical mechanical polishing (CMP) method for polishing a metal thin film,
The CMP slurry includes a polishing agent, an oxidizing agent, and at least one defect preventing agent for protecting the metal thin film.   The CMP slurry according to claim 1, wherein the defect preventing agent forms a protective film on the metal thin film.   The CMP slurry according to claim 1, wherein the defect preventing agent is adsorbed on a surface of the metal thin film.   The CMP slurry according to claim 1, wherein the defect preventing agent includes a polymer compound having a carboxyl group.   The CMP slurry according to claim 4, wherein the defect preventing agent includes a copolymer having acrylic acid.   The CMP slurry according to claim 1, wherein the amount of the defect preventing agent is 0.01 to 20% by weight based on the total weight of the CMP slurry.   The CMP according to any one of claims 4 to 6, wherein the defect preventing agent comprises at least one selected from the group consisting of PAA, PAMA, salts thereof, and mixtures thereof. slurry.   The CMP slurry according to claim 1, further comprising a chelating agent.   The CMP slurry according to claim 8, wherein the amount of the chelating agent is 0.01 to 20 wt% based on the total weight of the CMP slurry.   The CMP according to claim 8 or 9, wherein the chelating agent includes at least one selected from the group consisting of EDTA, NTA, DTPA, HEDTA, MGDA, salts thereof, and mixtures thereof. slurry.   11. The CMP slurry according to claim 1, wherein the amount of the abrasive is 0.5 to 20 wt% based on the total weight of the CMP slurry.   The CMP slurry according to any one of claims 1 to 11, wherein the abrasive includes at least one selected from the group consisting of colloidal silica and fumed silica.   The CMP slurry according to claim 1, wherein the amount of the oxidizing agent is 0.5 to 5 wt% based on the total weight of the CMP slurry.   The CMP slurry according to claim 1, wherein the oxidizing agent includes at least one selected from the group consisting of hydrogen peroxide and ammonium persulfate.   The CMP slurry according to any one of claims 1 to 14, further comprising a pH adjusting agent for adjusting the pH of the CMP slurry.   The CMP slurry according to claim 15, wherein the pH adjuster includes at least one selected from the group consisting of phosphoric acid, nitric acid, and sulfuric acid.   17. The CMP slurry according to claim 15, wherein the pH adjuster decreases a pH of the CMP slurry and increases a zeta potential between the metal thin film and the CMP slurry.   The CMP slurry according to claim 1, wherein the defect preventing agent lowers the pH of the CMP slurry.   The CMP slurry according to claim 1, wherein the defect preventing agent includes hydrogen ions.   The CMP slurry according to claim 1, wherein the metal thin film is aluminum or an aluminum alloy.   The CMP slurry according to claim 1, wherein the metal thin film forms a wiring or a plug. In a chemical mechanical polishing method for polishing a metal thin film formed on a substrate,
Preparing a CMP slurry comprising an abrasive, an oxidizing agent, and at least one defect inhibitor to protect the metal thin film;
Chemically mechanically polishing the metal thin film using the CMP slurry;
A chemical mechanical polishing method comprising:   The chemical mechanical polishing method according to claim 22, wherein the selective removal rate of the CMP slurry is 20: 1 to 1: 1.   The chemical mechanical polishing method according to claim 23, wherein a selective removal rate of the CMP slurry is 17: 1 to 1.5: 1.   The chemical mechanical polishing method according to any one of claims 22 to 24, wherein the defect preventing agent forms a protective film on the metal thin film.   The chemical mechanical polishing method according to any one of claims 22 to 25, wherein the defect preventing agent is adsorbed on a surface of the metal thin film.   27. The chemical mechanical polishing method according to any one of claims 22 to 26, wherein the defect preventing agent contains a polymer compound containing a carboxyl group.   28. The chemical mechanical polishing method according to claim 27, wherein the defect preventing agent includes a copolymer containing acrylic acid.   29. The chemical mechanical polishing method according to claim 22, wherein the amount of the defect preventing agent is 0.01 to 20% by weight based on the total weight of the CMP slurry. .   30. The chemistry according to any one of claims 27 to 29, wherein the defect preventing agent comprises at least one selected from the group consisting of PAA, PAMA, salts thereof, and mixtures thereof. Mechanical polishing method.   The chemical mechanical polishing method according to any one of claims 22 to 30, further comprising a chelating agent.   32. The chemical mechanical polishing method according to claim 31, wherein the amount of the chelating agent is 0.01 to 20% by weight based on the total weight of the CMP slurry.   33. The chemistry according to claim 31 or 32, wherein the chelating agent comprises at least one selected from the group consisting of EDTA, NTA, DTPA, HEDTA, MGDA, salts thereof, and mixtures thereof. Mechanical polishing method.   The chemical mechanical polishing method according to any one of claims 22 to 33, wherein the amount of the polishing agent is 0.5 to 20 wt% based on the total weight of the CMP slurry.   The chemical mechanical polishing method according to any one of claims 22 to 34, wherein the abrasive includes at least one selected from the group consisting of colloidal silica and fumed silica.   36. The chemical mechanical polishing method according to any one of claims 22 to 35, wherein the amount of the oxidizing agent is 0.5 to 5 wt% based on the total weight of the CMP slurry.   37. The chemical mechanical polishing method according to any one of claims 22 to 36, wherein the oxidizing agent includes at least one selected from the group consisting of hydrogen peroxide and ammonium persulfate.   The chemical mechanical polishing method according to any one of claims 22 to 37, further comprising a pH adjusting agent for adjusting the pH of the CMP slurry.   39. The chemical mechanical polishing method according to claim 38, wherein the pH adjuster includes at least one selected from the group consisting of phosphoric acid, nitric acid, and sulfuric acid.   The chemical mechanical polishing according to claim 38 or 39, wherein the pH adjuster decreases a pH of the CMP slurry to increase a zeta potential between the metal thin film and the CMP slurry. Method.   41. The chemical mechanical polishing method according to claim 22, wherein the defect preventing agent lowers the pH of the CMP slurry.   The chemical mechanical polishing method according to any one of claims 22 to 41, wherein the defect preventing agent contains hydrogen ions.   43. The chemical mechanical polishing method according to any one of claims 22 to 42, wherein the metal thin film is aluminum or an aluminum alloy.   44. The chemical mechanical polishing method according to any one of claims 22 to 43, wherein the metal thin film forms a wiring or a plug. In a chemical mechanical polishing method for a metal thin film formed on a substrate,
Preparing a first slurry containing an abrasive and an oxidizing agent;
Chemically mechanically polishing the metal thin film using the first slurry;
Preparing a second slurry comprising an abrasive, an oxidizing agent, and at least one defect inhibitor for protecting the metal thin film;
Chemically mechanically polishing the metal thin film using the second slurry;
A chemical mechanical polishing method comprising:   46. The chemical mechanical polishing method of claim 45, wherein the selective removal rate of the first slurry is greater than the selective removal rate of the second slurry.   47. The selective removal rate of the first slurry is 50: 1 or more, and the selective removal rate of the second slurry is 20: 1 to 1: 1. Chemical mechanical polishing method.   48. The chemical mechanical polishing method according to claim 47, wherein a selective removal rate of the second slurry is 17: 1 to 1.5: 1.   49. The chemical mechanical polishing method according to claim 45, wherein the defect preventing agent forms a protective film on the metal thin film.   50. The chemical mechanical polishing method according to claim 45, wherein the defect preventing agent is adsorbed on the surface of the metal thin film.   51. The chemical mechanical polishing method according to claim 45, wherein the defect preventing agent contains a polymer compound containing a carboxyl group.   52. The chemical mechanical polishing method according to claim 51, wherein the defect preventing agent includes a copolymer containing acrylic acid.   53. The chemical mechanical polishing method according to claim 45, wherein the amount of the defect preventing agent is 0.01 to 20% by weight based on the total weight of the CMP slurry. .   54. The chemistry according to any one of claims 51 to 53, wherein the defect prevention agent comprises at least one selected from the group consisting of PAA, PAMA, salts thereof, and mixtures thereof. Mechanical polishing method.   The chemical mechanical polishing method according to any one of claims 45 to 54, further comprising a chelating agent.   56. The chemical mechanical polishing method according to claim 55, wherein the amount of the chelating agent is 0.01 to 20% by weight based on the total weight of the CMP slurry.   57. The chemistry of claim 55 or 56, wherein the chelating agent comprises at least one selected from the group consisting of EDTA, NTA, DTPA, HEDTA, MGDA, salts thereof, and mixtures thereof. Mechanical polishing method.   58. The chemical mechanical polishing method according to any one of claims 45 to 57, wherein the amount of the abrasive is about 0.5 to 20% by weight based on the total weight of the CMP slurry. .   59. The chemical mechanical polishing method according to any one of claims 45 to 58, wherein the abrasive includes at least one selected from the group consisting of colloidal silica and fumed silica.   [Claim 60] The chemical mechanical polishing method according to any one of claims 45 to 59, wherein the amount of the oxidizing agent is 0.5 to 5 wt% based on the total weight of the CMP slurry.   61. The chemical mechanical polishing method according to claim 60, wherein the oxidizing agent includes at least one selected from the group consisting of hydrogen peroxide and ammonium persulfate.   The chemical mechanical polishing method according to any one of claims 45 to 61, further comprising a pH adjuster for adjusting the pH of the CMP slurry.   64. The chemical mechanical polishing method according to claim 62, wherein the pH adjuster includes at least one selected from the group consisting of phosphoric acid, nitric acid, and sulfuric acid.   64. The chemical mechanical polishing method according to claim 62 or 63, wherein the pH regulator lowers the pH of the CMP slurry and increases the zeta potential between the metal thin film and the CMP slurry. .   The chemical mechanical polishing method according to any one of claims 45 to 64, wherein the defect preventing agent lowers the pH of the CMP slurry.   The chemical mechanical polishing method according to any one of claims 45 to 65, wherein the defect preventing agent contains hydrogen ions.   67. The chemical mechanical polishing method according to claim 45, wherein the metal thin film is aluminum or an aluminum alloy.   68. The chemical mechanical polishing method according to any one of claims 45 to 67, wherein the metal thin film forms a wiring or a plug.