JP4406554B2 - Polishing composition - Google Patents

Description

  The present invention relates to a polishing composition used for polishing for forming a wiring structure of a semiconductor device.

  In recent years, along with the high integration and high speed of ULSI used in computers, the design rules of semiconductor devices have been miniaturized. Therefore, in order to cope with an increase in wiring resistance due to miniaturization of the wiring structure of a semiconductor device, it has been studied to use a metal material containing copper as a wiring material.

  When a metal material containing copper is used as a wiring material, it is difficult to form a wiring structure by anisotropic etching because of the nature of the metal material. For this reason, the wiring structure is formed by a method using a CMP (Chemical Mechanical Polishing) method or the like. Specifically, a barrier film made of a tantalum-containing compound such as tantalum or tantalum nitride is formed on an insulating film having a wiring groove formed on the surface thereof. Next, a conductor film formed of a metal material containing copper is formed on the barrier film so that at least the inside of the wiring groove is completely filled. Subsequently, a part of the conductor film is polished in the first polishing step. Then, in the second polishing step, the conductor film is polished until the barrier film in a portion other than the wiring groove is exposed. Next, in the third polishing step, the barrier film is polished until the insulating film in a portion other than the wiring groove is exposed, thereby forming a wiring portion in the wiring groove.

Conventionally, the polishing composition contains an abrasive such as silicon dioxide, α-alanine, hydrogen peroxide, and water (see, for example, Patent Document 1). In addition, some contain an abrasive such as alumina, an oxidizing agent such as peracetic acid, a complexing agent such as citric acid, and a film forming agent such as imidazole (see, for example, Patent Document 2). These polishing compositions mechanically polish the surface to be polished with an abrasive and promote polishing of a metal material containing copper with α-alanine, a complexing agent or the like.
JP 2000-160141 A Japanese Patent Laid-Open No. 11-21546

  However, when these polishing compositions are used in the second polishing step, the conductive film is excessively polished because the polishing rate for the metal material containing copper is high. Therefore, the polished surface after polishing has a problem that the surface of the conductor film corresponding to the wiring groove retreats inward compared to the surface of the barrier film, that is, dishing occurs.

  The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a polishing composition capable of suppressing the occurrence of dishing and maintaining a high polishing rate for a metal material containing copper.

（式中、Ｙはアルキレン基を示す。） In order to achieve the above object, the polishing composition of the invention described in claim 1 is used for polishing a semiconductor substrate and contains the following components (a) to (f).
(A): 0.01-2 mass% of α-amino acid
(B): A benzotriazole derivative represented by any one of the following general formulas (2) to (5), and when the benzotriazole derivative is represented by the general formula (2), 0.0005 to 0.00. 01 mass%, when expressed by general formula (3), 0.00005 to 0.005 mass%, when expressed by general formula (4) or general formula (5), 0.001 to 0.1 mass Set to%

(In the formula, Y represents an alkylene group.)

( C): Silicon oxide (d): Surfactant (e): Oxidizing agent (f): Water

The polishing composition of the invention according to 請 Motomeko 2 is the invention according to claim 1, component (a) it is alanine.

  According to the polishing composition of the present invention, the occurrence of dishing can be suppressed, and the polishing rate for a metal material containing copper can be kept high.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments embodying the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1A, a wiring groove 13 having a predetermined pattern based on circuit design is formed on the surface of an insulating film 12 on a semiconductor substrate 11 constituting a semiconductor device by a known lithography technique or pattern etching technique. Has been. Examples of the insulating film 12 include a SiOF film, a SiOC film, and the like in addition to a SiO ₂ film formed by a method such as a CVD (Chemical Vapor Deposition) method using TEOS (tetraethoxysilane).

  A barrier film 14 having a predetermined thickness is formed on the insulating film 12 by sputtering or the like. The barrier film 14 is formed of a tantalum-containing compound such as tantalum or tantalum nitride. A portion corresponding to the wiring groove 13 on the surface of the barrier film 14 is formed in a concave shape. A conductor film 15 is formed on the barrier film 14 so that at least the inside of the wiring trench 13 is completely filled. The conductor film 15 is formed of a metal material containing copper (hereinafter referred to as a copper-containing metal) such as copper, a copper-aluminum alloy, or a copper-titanium alloy. In a portion corresponding to the wiring groove 13 on the surface of the conductor film 15, an initial concave groove 16 derived from the wiring groove 13 generally called an initial step is formed.

  The wiring structure of the semiconductor device is formed by polishing the semiconductor substrate 11 by a CMP method. Specifically, as shown in FIG. 1B, the conductor film 15 is polished in the first polishing step. The polishing of the conductor film 15 by the first polishing process is finished before the barrier film 14 is exposed. After the first polishing process, as shown in FIG. 1C, the conductor film 15 is polished in the second polishing process until the barrier film 14 at portions other than the wiring grooves 13 is exposed. Subsequently, as shown in FIG. 1D, the barrier film 14 is polished until the insulating film 12 is exposed in the third polishing step, whereby the wiring portion 17 is formed in the wiring groove 13. In the present embodiment, a polishing composition used in the second polishing step is shown.

  The polishing composition of the present embodiment includes (a) an α-amino acid, (b) a benzotriazole derivative, (c) silicon oxide, (d) a surfactant, (e) an oxidizing agent, and (f) water. Contains ingredients.

  The α-amino acid of the component (a) has a dishing amount reducing action and reduces the dishing amount to suppress the occurrence of dishing. When this dishing occurs, the cross-sectional area of the wiring portion 17 decreases, so that the wiring resistance increases, and the flatness of the surface of the semiconductor substrate 11 decreases, so that it is difficult to make the wiring structure multi-layered. . As shown in FIG. 2A, the dishing amount is a depth direction distance (height difference) d between the surface of the barrier film 14 other than the wiring groove 13 and the surface of the conductor film 15. It is.

  Furthermore, the component (a) has a polishing promoting action for increasing the polishing rate for the copper-containing metal to a range suitable for polishing and removing the copper-containing metal. This is exhibited by component (a) chelating with copper during polishing. Examples of the α-amino acid include alanine, glycine, and valine. These may be contained alone or in combination of two or more. Among these, alanine is preferable because it has a strong dishing amount reducing effect and high solubility in the component (f).

  The content of the component (a) in the polishing composition is preferably 0.01 to 2% by mass, and more preferably 0.4 to 1.5% by mass. When the content of the component (a) is less than 0.01% by mass, the effect of reducing the dishing amount is weak and it is difficult to suppress the occurrence of dishing. On the other hand, when it exceeds 2 mass%, the grinding | polishing with respect to a copper containing metal will be suppressed by the component (a), and the grinding | polishing rate with respect to a copper containing metal will fall. Furthermore, the copper-containing metal remains on the polished surface after polishing because the removal of the copper-containing metal by polishing becomes insufficient. Therefore, there is an increased possibility that the clearness indicating the flatness of the surface to be polished will deteriorate.

  The benzotriazole derivative of component (b) is represented by the following general formula (1), and prevents corrosion of the surface of the conductor film 15 by protecting the copper-containing metal from corrosion by the component (e). Furthermore, the component (b) suppresses excessive polishing of the conductor film 15 by the protective action on the surface of the conductor film 15 and suppresses the occurrence of dishing.

（式中、Ｒはカルボキシル基を含有するアルキル基、ヒドロキシル基と３級アミノ基とを含有するアルキル基、ヒドロキシル基を含有するアルキル基又はアルキル基を示す。）
上記一般式（１）で示されるベンゾトリアゾール誘導体において、Ｒがカルボキシル基を含有するアルキル基を示すものとしては下記一般式（２）で示されるものが挙げられ、具体例としては下記式（６）で示される１−（１，２−ジカルボキシエチル）ベンゾトリアゾールが挙げられる。

(In the formula, R represents an alkyl group containing a carboxyl group, an alkyl group containing a hydroxyl group and a tertiary amino group, an alkyl group containing a hydroxyl group, or an alkyl group.)
In the benzotriazole derivative represented by the above general formula (1), examples in which R represents an alkyl group containing a carboxyl group include those represented by the following general formula (2). Specific examples thereof include the following formula (6) 1- (1,2-dicarboxyethyl) benzotriazole represented by formula (1).

また、Ｒがヒドロキシル基と３級アミノ基とを含有するアルキル基を示すものとしては下記一般式（３）で示されるものが挙げられ、具体例としては下記式（７）で示される１−［Ｎ，Ｎ−ビス（ヒドロキシエチル）アミノメチル］ベンゾトリアゾールが挙げられる。

Moreover, as what shows R the alkyl group containing a hydroxyl group and a tertiary amino group, what is shown by following General formula (3) is mentioned, As a specific example, 1-type shown by following formula (7) is mentioned. [N, N-bis (hydroxyethyl) aminomethyl] benzotriazole.

Ｒがヒドロキシル基を含有するアルキル基を示すものとしては下記一般式（４）又は下記一般式（５）で示されるものが挙げられる。これら具体例としては、下記式（８）で示される１−（２，３−ジヒドロキシプロピル）ベンゾトリアゾール又は下記式（９）で示される１−（ヒドロキシメチル）ベンゾトリアゾールが挙げられる。

As what shows R the alkyl group containing a hydroxyl group, what is shown by following General formula (4) or following General formula (5) is mentioned. Specific examples thereof include 1- (2,3-dihydroxypropyl) benzotriazole represented by the following formula (8) or 1- (hydroxymethyl) benzotriazole represented by the following formula (9).

前記一般式（２）〜（５）において、Ｙはアルキレン基を示す。前記一般式（２）〜（５）で示されるベンゾトリアゾール誘導体は単独で含有されてもよいし、二種以上が組み合わされて含有されてもよい。成分（ｂ）は、前記一般式（２）〜（５）で示されるものが、導体膜１５表面の保護作用がより強いために好ましい。

In the general formulas (2) to (5), Y represents an alkylene group. The benzotriazole derivatives represented by the general formulas (2) to (5) may be contained alone or in combination of two or more. The component (b) is preferably represented by the general formulas (2) to (5) because the protective action of the surface of the conductor film 15 is stronger.

  The content of the component (b) in the polishing composition is preferably 0.1% by mass or less. Furthermore, 0.0005-0.01 mass% is more preferable when a component (b) is shown by the said General formula (2), and 0.002-0.008 mass% is the most preferable. On the other hand, when the component (b) is represented by the general formula (3), 0.00005 to 0.005 mass% is more preferable, and 0.0001 to 0.001 mass% is most preferable. When the component (b) is represented by the general formula (4) or the general formula (5), 0.001 to 0.1% by mass is more preferable, and 0.003 to 0.005% by mass is most preferable. When the content of the component (b) is less than the above range, the effect of protecting the conductor film surface and the effect of reducing the dishing amount are low, and the surface of the conductor film after polishing is roughened and the risk of dishing is increased. On the other hand, when the content of the component (b) exceeds the above range, polishing of the copper-containing metal is suppressed, and the polishing rate for the copper-containing metal is lowered and the clearness of the surface to be polished is likely to be deteriorated.

The component (c) silicon oxide has a mechanical polishing action on the surface to be polished. Examples of the silicon oxide include colloidal silica (Colloidal SiO ₂ ), fumed silica (Fumed SiO ₂ ), precipitated silica (Precipitated SiO ₂ ), and other production methods and various types having different properties. These may be contained alone or in combination of two or more. Among these, colloidal silica or fumed silica is preferable, and colloidal silica is more preferable because the polishing rate for the copper-containing metal is high.

The particle diameter of the component (c) is preferably 0.01 to 0.5 μm, more preferably 0.03 to 0.3 μm in terms of the average particle diameter (D _N4 ) determined by the laser diffraction scattering method. When DN ₄ is less than 0.01 μm, the mechanical polishing action of the component (c) is weak, and the polishing rate for the copper-containing metal is lowered and the clearness of the polished surface is likely to be deteriorated. On the other hand, when it exceeds 0.5 μm, the polishing rate for the copper-containing metal becomes excessively high, and the dishing amount increases. Furthermore, not only the conductor film 15 but also the barrier film 14 and the insulating film 12 are polished, and the amount of erosion increases. In addition, since the sedimentation property of the component (c) is increased, it is difficult for the polishing composition to maintain the dispersed state of the component (c), and the possibility that the stability is lowered is increased.

  Here, as shown in FIG. 2B, the erosion is caused by polishing the barrier film 14 and the insulating film 12 in the region where the wiring trenches 13 are densely formed, so that the surface of the region is different. This means that the area of the barrier film 14 recedes inward compared with the surface of the barrier film 14. When this erosion occurs, the wiring resistance increases as in the case of dishing, and it becomes difficult to make the wiring structure multi-layered. The amount of erosion is the distance (height in the depth direction) between the surface of the region where the wiring grooves 13 are densely formed and the surface of the barrier film 14 in the region where the wiring grooves 13 are sparsely formed. Difference) e. The erosion occurs due to the increase in the erosion amount.

  0.01-10 mass% is preferable and, as for content of the component (c) in polishing composition, 0.1-3 mass% is more preferable. When the content of component (c) is less than 0.01% by mass, a sufficient polishing rate for the surface to be polished cannot be obtained, and the clearness of the surface to be polished is likely to deteriorate. On the other hand, if it exceeds 10% by mass, the polishing rate for a copper-containing metal or the like becomes excessively high, and the risk of causing dishing and erosion increases.

  The surfactant of component (d) has a dishing amount reducing action and suppresses the occurrence of dishing. As the surfactant, coconut oil fatty acid sarcosine triethanolamine represented by the following formula (10), coconut oil fatty acid methyl taurine sodium represented by the following formula (11), polyoxyethylene coconut oil represented by the following formula (12) Fatty acid monoethanolamide sodium sulfate, polyoxyethylene alkylphenyl ether phosphoric acid represented by the following formula (13), dodecylbenzenesulfonic acid triethanolamine represented by the following formula (14), polyoxy represented by the following formula (15) Ethylene alkyl (12-14) disodium sulfosuccinate, sulfosuccinate (dioctyl) represented by the following formula (16), polyoxyethylene lauryl ether sulfate triethanolamine represented by the following formula (17), ) Diisobutyldimethylbutane Emissions diol polyoxyethylene glycol ether.

研磨用組成物中の成分（ｄ）の含有量は０．０２５〜０．２質量％が好ましく、０．０３〜０．１質量％がより好ましい。成分（ｄ）の含有量が０．０２５質量％未満では、ディッシング量低減効果が低い。一方、０．２質量％を超えると、銅含有金属に対する研磨が成分（ｄ）により抑制されるおそれが高い。

The content of the component (d) in the polishing composition is preferably 0.025 to 0.2 mass%, more preferably 0.03 to 0.1 mass%. When the content of the component (d) is less than 0.025% by mass, the dishing amount reducing effect is low. On the other hand, when it exceeds 0.2 mass%, there is a high possibility that polishing of the copper-containing metal is suppressed by the component (d).

  The oxidizing agent of component (e) generates an oxide film that is easily peeled off by oxidizing the copper-containing metal, and promotes mechanical polishing by component (c). The oxidizing agent generally has an oxidizing power sufficient to oxidize copper. Specific examples thereof include persulfates such as ammonium persulfate, potassium persulfate, and sodium persulfate, periodic acid, and peracetic acid. , Perchloric acid, ammonium percarbonate, hydrogen peroxide and the like. Among these, persulfate is preferable because of its strong oxidizing power against copper, and ammonium persulfate is more preferable.

  0.5-10 mass% is preferable and, as for content of the component (e) in polishing composition, 1-5 mass% is more preferable. If it is less than 0.5% by mass, the polishing promoting effect is low, and the possibility that the polishing rate for the copper-containing metal is lowered increases. On the other hand, if it exceeds 10% by mass, the polishing rate for the copper-containing metal becomes excessively high and the risk of dishing increases.

  The water of component (f) dissolves or disperses other components. The component (f) preferably contains as little impurities as possible in order to prevent the action of other components from being inhibited. Specifically, component (f) is preferably pure water, ultrapure water, or distilled water from which foreign ions are removed through a filter after removing impurity ions with an ion exchange resin. The content of component (f) in the polishing composition is the remaining amount with respect to the content of other components in the polishing composition.

  The polishing composition may contain a thickener, an antifoaming agent, a preservative, and the like as other additive components in addition to the above-described components, depending on the necessity for stabilization and polishing processing. Content of the other additional component in polishing composition is determined in accordance with the normal method of polishing composition. The polishing composition is prepared by mixing the component (f) with other components and dispersing or dissolving each component by, for example, stirring with a blade-type stirrer or ultrasonic dispersion. Here, the mixing order of the other components with respect to the component (f) is not limited.

  The pH of the polishing composition is preferably 7 or more, more preferably 7 to 12, and most preferably 8 to 10. When the pH of the polishing composition is less than 7, polishing removal of the copper-containing metal does not proceed sufficiently and the polishing rate decreases. On the other hand, if it exceeds 12, the polishing rate for the copper-containing metal becomes excessively high, and dishing may occur. Adjustment of pH of polishing composition is performed by mixing | blending ammonia etc.

  When polishing the conductor film 15 using the polishing composition of the present embodiment in the second polishing step, the polishing pad is supplied while supplying the polishing composition to the surface of the conductor film 15 after the first polishing step. The conductor film 15 is pressed against the surface and rotated. At this time, the polishing composition can polish the conductor film 15 by mechanically polishing the surface to be polished with the component (c). Therefore, since the polishing composition of the embodiment contains the components (a), (b) and (d), the occurrence of dishing can be suppressed by these components. Further, the polishing composition can maintain a high polishing rate for the copper-containing metal by the components (a) and (e).

(Test Examples 1-33 and Comparative Examples 1-16)
In Test Example 1, alanine (0.01% by mass) as component (a), 1- (2,3dihydroxypropyl) benzotriazole (0.01% by mass), component (c) as component (b) Colloidal silica as a component (0.5% by mass), coconut oil fatty acid sarcosine triethanolamine (0.02% by mass) and polyoxyethylene lauryl ether sulfate triethanolamine (0.015% by mass) as component (d), A polishing composition was prepared by mixing ammonium persulfate (1% by mass) as component (e) and water of component (f). Here, colloidal silica, N4 Plus Submicron Particle Sizer (Beckman Coulter, Inc. product name) was measured at but 0.05μm at D _N4, iron in the 20 wt% aqueous solution of nickel, copper, chromium, zinc And the total content of calcium was 20 ppb or less.

  In Test Examples 2-33 and Comparative Examples 1-16, a polishing composition was prepared in the same manner as in Test Example 1, except that the type or content of each component was changed as shown in Table 1 or Table 2. . And while measuring pH of each polishing composition, it evaluated about each following item. The results are shown in Tables 1 and 2. In addition, in each table | surface, content (mass%) is shown by "amount", and the component in which description of content is abbreviate | omitted is the same content as Test Example 1. However, in Test Example 27, the content of A1 was set to 0.035% by mass.

<Polishing rate: R>
The thickness of the copper blanket wafer was measured using a sheet resistance machine (VR-120; manufactured by Kokusai Electric System Service Co., Ltd.). Next, the copper blanket wafer surface was polished for 1 minute using the polishing composition of each example and the following polishing condition 1. And after measuring the thickness of the copper blanket wafer after grinding | polishing similarly to the above, the grinding | polishing speed | rate was calculated | required based on the following formula.

Polishing rate [nm / min] = (thickness of copper blanket wafer before polishing [nm] −thickness of copper blanket wafer after polishing [nm]) ÷ polishing time [min]
<Polishing condition 1>
Polishing machine: Polishing machine for single-sided CMP (Mirra; manufactured by Applied Materials), polishing target: copper blanket wafer (8-inch silicon wafer on which copper is formed by electrolytic plating), polishing pad: laminated polishing made of polyurethane Pad (IC-1000 / Suba400; manufactured by Rodel), polishing pressure: 2 psi (= about 13.8 kPa), platen rotation speed: 60 rpm, polishing composition supply speed: 200 ml / min, carrier rotation speed: 60 rpm
<Dishing amount: d and clearness of polished surface: C>
The copper pattern wafer surface was polished under the following polishing condition 2 while using a polishing composition for the first polishing step (PLANERELITE-7102; manufactured by Fujimi Incorporated). The polishing amount was 70% (700 nm) of the initial film thickness. After the polishing, the polishing pattern of each example was used on the surface of the copper pattern wafer, and under the polishing condition 1, after the end point signal appeared, the copper film was polished over 200 nm. Next, the dishing amount (nm) was measured using a profila (HRP340; manufactured by KLA-Tencor Corporation), which is a contact-type surface measuring device, in an isolated wiring portion having a width of 100 μm on the surface of the copper pattern wafer after the second polishing. Furthermore, the amount of the copper-containing metal remaining on the barrier film other than the copper wiring portion was visually observed using a differential interference microscope (OPTIPHOTO300; manufactured by NIKON).

And about the clearness of the surface to be polished, (◎) No copper-containing metal residue is observed, (○) Spot-like copper-containing metal residue is slightly observed, (△) Overall spot-like Although the copper-containing metal remains, the range that can be polished and removed in the third polishing step, (x) the copper-containing metal remains in the whole and the wiring part is not visible, and it is difficult to polish and remove in the third polishing step Evaluation was made in 4 stages.
<Polishing condition 2>
Polishing machine: single-side CMP polishing machine (Mirra; manufactured by Applied Materials), polishing target: copper pattern wafer (manufactured by SEMATECH, 854 mask pattern, film thickness 1000 nm, initial concave groove 800 nm), polishing pad: polyurethane Laminated polishing pad (IC-1400; manufactured by Rodel), polishing pressure: 2.0 psi (= about 13.8 kPa), platen rotation speed: 100 rpm, polishing composition supply rate: 200 ml / min, carrier Rotation speed: 100rpm
<Pot life: P>
Immediately after the preparation of the polishing composition, the polishing rate was determined in the same manner as in the above item <Polishing rate>. Next, the polishing composition was stored in a sealed container, and the polishing rate was determined in the same manner as described above every time a fixed period elapsed after the start of storage. Subsequently, the elapsed time when the polishing rate decreased by 90% with respect to the polishing rate immediately after preparation was defined as the pot life. The pot life was evaluated in four stages: (◎) 2 weeks or more, (◯) 1 week or more and less than 2 weeks, (Δ) 3 days or more and less than 1 week, (x) less than 3 days.

＜成分（ａ）及び研磨促進剤＞Ａｌａ：アラニン、Ｇｌｙ：グリシン、Ｖａｌ：バリン、Ｃｉｔ：クエン酸、ＬＡ：乳酸、Ｏｘａ：シュウ酸、ＮＡ：硝酸、ＳＡ：硫酸
＜成分（ｂ）及び防食剤＞Ｇ：１−（２，３ジヒドロキシプロピル）ベンゾトリアゾール、Ｈ：１−［Ｎ，Ｎ−ビス（ヒドロキシジメチル）アミノメチル］−ベンゾトリアゾール、Ｉ：１−（１，２−ジカルボキシエチル）ベンゾトリアゾール、Ｊ：ベンゾトリアゾール
＜成分（ｃ）＞ＣＳ１：Ｄ_N4が０．０３μｍのコロイダルシリカ、ＣＳ２：Ｄ_N4が０．０５μｍのコロイダルシリカ、ＣＳ３：Ｄ_N4が０．０７μｍのコロイダルシリカ、ＦＳ３：Ｄ_N4が０．０７μｍのフュームドシリカ
＜成分（ｄ）＞Ａ１：ヤシ油脂肪酸サルコシントリエタノールアミン、Ａ２：ヤシ油脂肪酸メチルタウリンナトリウム、Ａ３：ポリオキシエチレンヤシ油脂肪酸モノエタノールアミド硫酸ナトリウム、Ｂ１：ポリオキシエチレンアルキルフェニルエーテルリン酸、Ｂ２：ドデシルベンゼンスルホン酸トリエタノールアミン、Ｃ１：ポリオキシエチレンアルキル（１２〜１４）スルホコハク酸二ナトリウム、Ｃ２：スルホコハク酸塩、Ｄ：ポリオキシエチレンラウリルエーテル硫酸トリエタノールアミン、Ｅ：ジイソブチルジメチルブチンジオールポリオキシエチレングリコールエーテル
＜成分（ｅ）＞ＡＰＳ：過硫酸アンモニウム、ＨＰＯ：過酸化水素
表１に示すように、試験例１〜３３においては、ディッシング量を低減してディッシングの発生を抑制するとともに、銅含有金属に対する研磨速度を高く維持することができた。試験例１〜５に示すように、成分（ａ）の含有量を０．５〜１．５質量％にすることにより、銅含有金属に対する研磨速度を高く維持しつつディッシング量を特に低減することができた。一方、試験例６〜８に示すように、成分（ｂ）の含有量を０．００５〜０．０２質量％にすることにより、ディッシング量を特に低減することができた。

<Component (a) and polishing accelerator> Ala: alanine, Gly: glycine, Val: valine, Cit: citric acid, LA: lactic acid, Oxa: oxalic acid, NA: nitric acid, SA: sulfuric acid <component (b) and anticorrosion Agent> G: 1- (2,3-dihydroxypropyl) benzotriazole, H: 1- [N, N-bis (hydroxydimethyl) aminomethyl] -benzotriazole, I: 1- (1,2-dicarboxyethyl) Benzotriazole, J: Benzotriazole <Component (c)> CS1: Colloidal silica with D _N4 of 0.03 μm, CS2: Colloidal silica with D _N4 of 0.05 μm, CS3: Colloidal silica with D _N4 of 0.07 μm, FS3 : D _N4 is fumed silica 0.07 .mu.m <component (d)> A1: coconut oil fatty acid sarcosine triethanolamine, A2: coconut oil fatty Methyl taurine sodium, A3: sodium polyoxyethylene coconut oil fatty acid monoethanolamide sulfate, B1: polyoxyethylene alkylphenyl ether phosphate, B2: triethanolamine dodecylbenzenesulfonate, C1: polyoxyethylene alkyl (12-14) Disodium sulfosuccinate, C2: sulfosuccinate, D: polyoxyethylene lauryl ether triethanolamine sulfate, E: diisobutyldimethylbutynediol polyoxyethylene glycol ether <component (e)> APS: ammonium persulfate, HPO: hydrogen peroxide As shown in Table 1, in Test Examples 1 to 33, the dishing amount was reduced to suppress the occurrence of dishing, and the polishing rate for the copper-containing metal could be kept high. As shown in Test Examples 1 to 5, by reducing the content of the component (a) to 0.5 to 1.5 mass%, particularly reducing the dishing amount while maintaining a high polishing rate for the copper-containing metal. I was able to. On the other hand, as shown in Test Examples 6 to 8, the dishing amount could be particularly reduced by setting the content of the component (b) to 0.005 to 0.02% by mass.

In addition, this embodiment can also be changed and embodied as follows.
-When the polishing composition is prepared, the content of the component (f) is set lower than when used in the polishing step, so that components other than the component (f) are concentrated and used in the polishing step. It may be configured such that component (f) is added and diluted when applied. When comprised in this way, management of polishing composition can be performed easily and transportation efficiency can be improved.

  The polishing composition may be prepared and stored in a state where the component (e) and the other component are separately separated, and the component (e) may be added to the other component immediately before use. When comprised in this way, decomposition | disassembly of a component (e) can be suppressed when a polishing composition is stored for a long period of time.

  When forming the wiring structure, the conductor film 15 is polished in the first polishing process until the barrier film 14 at a portion other than the wiring groove 13 is exposed. Next, polishing may be performed until the insulating film 12 is exposed in the second polishing step. At this time, the polishing composition is used in the first polishing step.

(A)-(d) is a partial expanded end view which shows the grinding | polishing method of this embodiment typically. (A) is a partial enlarged end view schematically showing dishing, and (b) is a partially enlarged end view schematically showing erosion.

Explanation of symbols

  11: Semiconductor substrate.

Claims (2)

A polishing composition used for polishing a semiconductor substrate and containing the following components (a) to (f).
(A): 0.01-2 mass% of α-amino acid
(B): A benzotriazole derivative represented by any one of the following general formulas (2) to (5), and when the benzotriazole derivative is represented by the general formula (2), 0.0005 to 0.00. 01 mass%, when expressed by general formula (3), 0.00005 to 0.005 mass%, when expressed by general formula (4) or general formula (5), 0.001 to 0.1 mass Set to%

(In the formula, Y represents an alkylene group.)
(C): Silicon oxide (d): Surfactant (e): Oxidizing agent (f): Water The polishing composition according to claim 1, wherein the component (a) is alanine .

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