TWI772323B - Chemical mechanical polishing composition and chemical mechanical polishing method - Google Patents

Abstract

An object of the present invention is to provide a chemical mechanical polishing composition useful in the manufacture of semiconductor devices, and a chemical mechanical polishing method using the same, which can achieve good polishing characteristics while suppressing the corrosion of the cobalt film. As a solution, the composition for chemical mechanical polishing related to the present invention is a composition for chemical mechanical polishing containing silica particles and peroxides, and is characterized in that the density of silanol groups of the silica particles is 3~3~ 6 particles/nm ² , when the content of the silica particles is Ma (parts by mass) and the content of the peroxides is Mc (parts by mass), the value of Ma/Mc is 200 or more and 700 or less.

Description

Chemical mechanical polishing composition and chemical mechanical polishing method

The present invention relates to a chemical mechanical polishing composition and a chemical mechanical polishing method using the same.

[0002] With the development of high-definition semiconductor devices, the miniaturization of wiring layers formed of wirings, plugs, and the like formed in the semiconductor devices is gradually progressing. Along with this, there is a method of flattening the wiring layer by chemical mechanical polishing (hereinafter also referred to as "CMP"). In recent years, in order to miniaturize to a node of 10 nm or more, it is required to apply cobalt to these conductor metals, to efficiently remove the remaining deposited cobalt by CMP, and to suppress corrosion of the highly reactive cobalt. good surface condition. Regarding the chemical mechanical polishing of such a cobalt layer and cobalt plug (hereinafter also referred to as "cobalt film"), for example, Patent Document 1 discloses a chemical mechanical polishing composition with a pH of 5 or more and a neutral region of 8.3 or less, This is a semiconductor polishing composition used in a stage corresponding to the first polishing treatment step before completion of polishing, and contains an amino acid, a nitrogen-containing heterocyclic compound, and abrasive grains. In addition, Patent Document 2 discloses a chemical mechanical polishing method, which is a chemical mechanical polishing method using a cobalt etchant such as an oxidizing agent, a cobalt polishing rate enhancer, and a corrosion inhibitor, and using a pH of 7 or more and 12 or less in an alkaline region. The polishing composition is used to polish a cobalt-containing substrate. The chemical mechanical polishing composition used in this polishing method has revealed that the corrosion potential of cobalt as quantified by the Tafel plot is a positive potential of 0 mV or more. Furthermore, Patent Document 3 discloses a chemical mechanical polishing method, which comprises an etchant of cobalt such as an oxidizing agent, a metal anti-corrosion agent, and water, and uses a chemical mechanical polishing composition in an acidic region of pH 4 or less for polishing. Substrates containing cobalt. [PRIOR ART DOCUMENT] [PATENT DOCUMENT] [0006] [PATENT DOCUMENT 1] JP-A No. 2016-30831 [Patent Document 2] JP-A No. 2016-58730 [Patent Document 3] International Publication No. 2016/98817

[Problems to be Solved by the Invention] [0007] However, when a chemical mechanical polishing composition for polishing an acidic metal film is used in the past, when a metal film such as cobalt is polished by chemical mechanical polishing, the cobalt film is easily dissolved, which may cause problems. Abnormal oxidation or corrosion of cobalt wiring, disconnection and disappearance. In addition, in the conventional chemical mechanical polishing composition for basic metal polishing, the cobalt film is chemically stable and has a high hardness, so there is a problem that it is not easy to polish efficiently. Herein, several aspects related to the present invention are to provide a chemical mechanical polishing composition useful for the manufacture of a semiconductor device and a chemical mechanical polishing method using the same, which can solve at least a part of the above-mentioned problems, and suppress the Corrosion of the cobalt film while achieving good grinding characteristics. [Means for Solving the Problems] [0009] The present invention is intended to solve at least a part of the above-mentioned problems, and can be realized as the following aspects or application examples. [Application Example 1] One form of the composition for chemical mechanical polishing related to the present invention is a composition for chemical mechanical polishing containing silicon dioxide particles and peroxide, which is characterized by the silicon dioxide particles of the aforementioned silicon dioxide particles. The density of alcohol groups is 3 to 6 pieces/nm ² . When the content of the silica particles is taken as Ma (parts by mass) and the content of the peroxides is taken as Mb (parts by mass), the value of Ma/Mb is 200 or more Below 700. [Application Example 2] In the chemical mechanical polishing composition of Application Example 1, the ratio (Rmax/Rmin) of the long diameter (Rmax) to the short diameter (Rmin) of the silica particles can be 1.0 or more and 1.5 or less . [Application Example 3] In the chemical mechanical polishing composition of Application Example 1 or Application Example 2, the pH can be 7 or more and 11 or less. [Application Example 4] In the chemical mechanical polishing composition of any one of Application Example 1 to Application Example 3, the peroxide can be selected from ammonium persulfate, potassium persulfate, hydrogen peroxide, ferric nitrate ( III), at least one compound in the group consisting of ceric ammonium nitrate, iron sulfate, ozone, hypochlorous acid and its salts, potassium periodate and peracetic acid. [Application Example 5] The chemical mechanical polishing composition of any one of Application Examples 1 to 4 may further contain an anionic compound having one or more double bonds. [Application Example 6] The chemical mechanical polishing composition of any one of Application Examples 1 to 5 can be used for chemical mechanical polishing of a cobalt film. [Applied Example 7] One aspect of the chemical mechanical polishing method related to the present invention is characterized in that the chemical mechanical polishing composition of any one of Application Examples 1 to 6 is used, and the cobalt film is subjected to chemical mechanical polishing. Grinding step. [Effect of the Invention] [0017] The chemical mechanical polishing composition according to the present invention can suppress the corrosion of the cobalt film in the manufacture of a semiconductor device, while achieving good polishing characteristics. Therefore, the chemical mechanical polishing composition according to the present invention is particularly useful in CMP in which a cobalt film, which is a wiring material, is polished.

[0019] Hereinafter, suitable embodiments of the present invention will be described in detail. In addition, this invention is not limited to the following embodiment, In the range which does not change the summary of this invention, various modification examples of implementation are also included. 1. Composition for chemical mechanical polishing The composition for chemical mechanical polishing related to one embodiment of the present invention is characterized in that it contains silica particles and peroxide, and the silanol group density of the silica particles is 3 to 6 pieces/nm ² , when the content of the silica particles is Ma (parts by mass) and the content of the peroxides is Mb (parts by mass), the value of Ma/Mb is 200 or more and 700 or less. Hereinafter, the chemical mechanical polishing composition according to the present embodiment will be described in detail. [0021] 1.1. Silicon dioxide particles The chemical mechanical polishing composition related to this embodiment contains silicon dioxide particles with a silanol group density of 3 to 6 pieces/nm ² . As the silica particles, although silica particles such as colloidal silica and fumed silica are mentioned, colloidal silica is preferable. As colloidal silica, for example, what is produced by the method described in Japanese Unexamined Patent Publication No. 2003-109921 and the like can be used. And, as silicon dioxide particles, use the method as described in Japanese Unexamined Patent Publication No. 2010-269985 or J.Ind.Eng.Chem., Vol.12, No.6, (2006) 911-917 etc. The surface-modified silica particles are preferred. These silica particles are fixed to the surface via a common bond between at least one functional group selected from the group consisting of a sulfonic acid group and a salt thereof. Therefore, in the chemical mechanical polishing composition, the surface of the silica particles is negatively charged by the functional group, and the silica particles become easily adsorbed on the surface of the cobalt film. As a result, since the silicon dioxide particles are localized on the surface of the cobalt film, the mechanical polishing force is increased, and the polishing speed of the cobalt film is also increased. Surface modification of silicon dioxide particles, specifically, by fully stirring the silicon dioxide particles and the sulfhydryl-containing siloxane coupling agent in an acidic medium, on the surface of the silicon dioxide particles The sulfhydryl-based siloxane coupling agent has a shared bond, which can be achieved. Examples of the sulfhydryl group-containing siloxane coupling agent include 3-sulfhydrylpropylmethyldimethoxysiloxane, 3-sulfhydrylpropyltrimethoxysiloxane, and the like. After that, by adding an appropriate amount of hydrogen peroxide and allowing it to stand sufficiently, silica particles having at least one functional group selected from the group consisting of a sulfonic acid group and a salt thereof can be obtained. [0024] The “silanol group” of the silica particles in this embodiment refers to the hydroxyl groups directly bonded to the silicon atoms on the surface of the silica particles, and there is no particular limitation on the three-dimensional configuration or the three-dimensional coordination. In addition, the conditions for the formation of silanol groups and the like are also not specified. [0025] The “density of silanol groups” in this embodiment means the number of silanol groups per unit area on the surface of the silica particles, which is an index representing the electrical properties or chemical properties of the surfaces of the silica particles. The silanol group is generally negatively charged because H ⁺ of SiOH is separated and stably exists in the state of SiO ⁻ in the chemical mechanical polishing composition. Thereby, the electrical properties or chemical properties of the silicon dioxide particles are exhibited. The unit of silanol density is expressed in units/nm ² . [0026] The silanol group density of the silica particles can be obtained by the Sears method. The Sears method can be implemented with reference to GW Sears, Jr., "Determination of Specific Surface Area of Colloidal Silica by Titration with Sodium Hydroxide", Analytical Chemistry, 28(12), 1981 (1956). In the measurement, 0.1 mol/L of NaOH was titrated at a dropping rate of 2 mL/min using a 1 wt % silica aqueous solution, and the silanol group density was calculated based on the following formula. ρ=( _a ×b×NA )÷(c×d) In the above formula, respectively represent ρ: density of silanol groups (units/nm ² ), a: concentration of NaOH solution used for titration (mol/L) , b: Dropping volume of NaOH solution at pH 4-9 (mL), NA : _Yavogajue constant, c: mass of silica (g), d: BET specific surface area (nm ² /g). Here, the BET specific surface area of the silica particles is obtained from the specific surface area measured by the BET method by, for example, a flow-type specific surface area automatic measuring device "micrometrics FlowSorb II 2300 (manufactured by Shimadzu Corporation)". Calculate. [0028] The silanol group density of the silica particles used in this embodiment is 3-6 pieces/nm ² , preferably 3.1-6 pieces/nm ² , more preferably 4-6 pieces/nm ² , particularly preferably 5~6 pieces/nm ² . If the silanol group density is within the aforementioned range, it is presumed that the chemical reaction between cobalt and the silanol groups existing on the surface of the silica particles will be promoted, and the surface of the cobalt film will be modified. Although the specific reaction mechanism is not clear, it is believed that the Co-O site generated on the cobalt surface generated by the action of the peroxide in the polishing step interacts with the silanol group (Si-OH) on the surface of the silica particle. , so a modified layer that is easier to grind will be formed. As a result, the cobalt film is smoothly removed by the mechanical polishing action, so that favorable polishing characteristics can be realized.

Moreover, if the silanol group density of the silica particles is within the aforementioned range, the negative charge on the surface of the silica particles in the chemical mechanical polishing composition will increase, so by the electrostatic reaction force (Zeta potential), the two The silica particles can be stably dispersed in the chemical mechanical polishing composition, and it is possible to prevent aggregation of the silica particles, which can cause defects during CMP.

If the silanol group density of the silica particles is less than 3/nm ² , it is difficult to cause chemical reaction between cobalt and the silanol groups existing on the surface of the silica particles, and the surface of the cobalt film is difficult to be modified. Therefore, the polishing of the cobalt film is difficult. The speed will be reduced. In addition, the negative charge on the surface of the silica particles in the chemical mechanical polishing composition will become smaller, so the dispersion stability of the silica particles in the chemical mechanical polishing composition is likely to deteriorate, because the agglomerated silica particles, Scratches and the like may occur, and good polishing characteristics cannot be achieved.

On the other hand, if the density of the silanol groups of the silica particles exceeds 6/nm ² , the chemical reaction between cobalt and the silanol groups existing on the surface of the silica particles will become excessive, and corrosion of the cobalt film will easily occur.

The average particle size of the silica particles can be determined by measuring with a particle size distribution measuring apparatus using a dynamic light scattering method as a measurement principle. The average particle diameter of the silica particles is preferably 15 nm or more and 100 nm or less, more preferably 20 nm or more and 80 nm or less, and particularly preferably 30 nm or more and 70 nm or less. If the average particle size of the silica particles is within the aforementioned range, the practical polishing speed for the cobalt film can be achieved, and the sedimentation of the silica particles is difficult to occur. By separation, a chemical mechanical polishing composition excellent in storage stability can be obtained. As the particle size fraction using dynamic light scattering method as the measurement principle Cloth measuring device, there are examples of Beckman. Nanoparticle analyzer "DelsaNano S" manufactured by Coulter Corporation; "Zetasizer nano zs" manufactured by Malvern Corporation; "LB550" manufactured by Horiba Co., Ltd., etc. In addition, the average particle diameter measured by the dynamic light scattering method represents the average particle diameter of secondary particles formed by aggregating a plurality of primary particles.

The ratio Rmax/Rmin of the long diameter (Rmax) to the short diameter (Rmin) of the silica particles is preferably 1.0-1.5, more preferably 1.0-1.4, particularly preferably 1.0-1.3. When Rmax/Rmin is within the aforementioned range, defects in the cobalt film to be polished are not caused, and high polishing speed and high planarization properties can be achieved.

Here, the long diameter (Rmax) of the silica particle refers to the distance of the longest straight line connecting the end of the image and the end of the image of an independent silica particle photographed by a transmission electron microscope. . The short diameter (Rmin) of the silica particle refers to the distance of the shortest straight line connecting the end of the image and the end of the image of an independent silica particle photographed by a transmission electron microscope.

(上述一般式(1)中，R¹ 為碳數1~8之烷基或羧基，R² 表示具有羧基之碳數1~15之有機基或羧基。) 　　[0047] 　　【化2】

[0048] 　　【化3】

[0049] 上述一般式(2)以及上述一般式(3)中，R³ 、R⁴ 、R⁵ 以及R⁶ 各自獨立表示氫或具有羧基之碳數1~3之有機基或羧基。惟，R³ 以及R⁴ 之至少一者表示具有羧基之碳數1~3之有機基或羧基，R⁵ 以及R⁶ 之至少一者表示具有羧基之碳數1~3之有機基或羧基。 　　[0050] 作為具有一個以上雙鍵之陰離子性化合物之具體例，有舉例如馬來酸、丁烯二酸、喹啉酸、喹哪啶酸、油酸、烯基琥珀酸以及此等之鹽等，能夠使用此等之1種以上。 　　[0051] 具有一個以上雙鍵之陰離子性化合物之含量相對於化學機械研磨用組成物之全質量，較佳為0.0001~1質量%，再較佳為0.001~0.5質量%。具有一個以上雙鍵之陰離子性化合物之含有比例若在前述範圍，則能抑制鈷膜之腐蝕，同時對鈷膜之研磨速度會提升。 　　[0052] 1.6.化學機械研磨用組成物之pH 　　本實施形態相關之化學機械研磨用組成物之pH較佳為7以上11以下，再較佳為8以上11以下，特別佳為9以上11以下。pH若在前述範圍內，則能夠一邊抑制鈷膜之腐蝕，一邊研磨鈷膜，因此能夠得到良好之研磨特性。另一方面，若pH未滿7，則鈷膜之研磨速度雖然會提升，但容易產生鈷膜之腐蝕，故難以得到良好之研磨特性。 　　[0053] 作為調整化學機械研磨用組成物之pH之手段，有舉例如於化學機械研磨用組成物中添加鹼基之方法。作為能夠添加之鹼基，有舉例如氨、氫氧化鉀、氫氧化鈉、TMAH(四甲基氫氧化銨)等。此等之鹼基，能夠單獨使用1種單獨或組合2種以上來使用。 　　[0054] 1.7.用途 　　本實施形態相關之化學機械研磨用組成物能夠達到如上述對鈷膜之實用上的研磨速度，並同時具有鈷膜之腐蝕抑制效果。因此，本實施形態相關之化學機械研磨用組成物在半導體裝置之製造步驟中，作為用來將形成金屬配線、金屬閘以及金屬插頭等之鈷膜進行化學機械研磨之研磨材料較適合。 　　[0055] 1.8.化學機械研磨用組成物之調製方法 　　本實施形態相關之化學機械研磨用組成物能夠藉由使上述各成分溶解或分散於水等之液狀介質中來調製。使其溶解或分散之方法並無特別限制，只要是能夠均勻地溶解或分散，亦可適用任何方法。且，關於上述各成分之混合順序或混合方法並無特別限制。 　　[0056] 且，本實施形態相關之化學機械研磨用組成物能夠作為濃縮型式的原液來調製，使用時再以水等之液狀介質稀釋使用。 　　[0057] 2.化學機械研磨方法 　　本發明之一實施形態相關之化學機械研磨方法包含使用上述化學機械研磨用組成物，將鈷膜進行化學機械研磨之步驟。以下，關於本實施形態相關之化學機械研磨方法之一具體例，一邊使用圖式一邊詳細地說明。 　　[0058] 2.1.裝置(被處理體)之製作 　　圖4表示本實施形態相關之化學機械研磨方法中所使用之被處理體100。 　　(1)首先，於矽基板(無圖示)上以電漿CVD法或熱氧化法形成絕緣膜20。作為絕緣膜20，有舉例如TEOS膜等。 　　(2)絕緣膜20上，使用CVD法或熱氧化法形成保護膜30。作為保護膜30，有舉例如SiN膜等。 　　(3)以絕緣膜20以及保護膜30連通之方式來蝕刻，形成配線用凹部40。 　　(4)使用CVD法或PVD法，形成障壁金屬膜50，使其被覆保護膜30之表面以及配線用凹部40之底部及內壁面。障壁金屬膜50，以與鈷膜之接著性以及對絕緣膜及保護膜之擴散障壁性優異之觀點來看，為Ti或TiN較佳，但不限於此等，亦可為Ta、TaN、Mn、Ru等。 　　(5)以PVD法、CVD法或鍍敷法使鈷堆積於障壁金屬膜50之上，形成鈷膜60，藉此得到被處理體100。 　　[0059] 2.2.化學機械研磨方法 　　接著，對被處理體100進行二階段的研磨處理。作為第1研磨處理步驟，為了去除堆積於被處理體100之障壁金屬膜50上的鈷膜60，使用特開2016-30831號公報等中記載之對鈷表示高研磨速率之化學機械研磨用組成物，來進行化學機械研磨。藉由此化學機械研磨，繼續研磨鈷膜60至保護膜30或障壁金屬膜50露出於表面為止。通常，確認到保護膜30或障壁金屬膜50露出於表面之後，必須要使研磨停止。雖然對鈷膜之研磨速度非常高，但使用幾乎不研磨障壁金屬膜之化學機械研磨用組成物時，如圖5所示，由於在障壁金屬膜50露出於表面之時點，無法進行化學機械研磨，故能夠使化學機械研磨自己停止(Self-stop)。 　　[0060] 接著，作為第2研磨處理步驟，藉由使用上述本案發明之化學機械研磨用組成物，研磨鈷膜60與障壁金屬膜50與保護膜30或絕緣膜20共存之被處理面，能夠使鈷膜表面之腐蝕降低，同時不會使研磨速度降低地研磨。 　　[0061] 2.3.化學機械研磨裝置 　　本實施形態相關之化學機械研磨方法中，能夠使用市售之化學機械研磨裝置。作為市售之化學機械研磨裝置，有舉例如荏原製作所公司製、型式「EPO-112」、「EPO-222」；Lapmaster SFT公司製、型式「LGP-510」、「LGP-552」；Applied Material公司製、型式「Mirra」、「Reflexion」；G&P TECHNOLOGY公司製、型式「POLI-400L」等。 　　[0062] 作為較佳研磨條件，應該要因所使用之化學機械研磨裝置來適當地設定，但例如作為化學機械研磨裝置使用上述「EPO-112」時，能夠設為下述條件。 ・定盤迴轉數；較佳為30~120rpm，再較佳為40~100rpm ・頭部迴轉數；較佳為30~120rpm，再較佳為40~100rpm ・定盤迴轉數/頭部迴轉數比；較佳為0.5~2，再較佳為0.7~1.5 ・研磨壓力；較佳為60~200gf/cm² ，再較佳為100~150gf/cm² ・化學機械研磨用組成物供給速度；較佳為50~300mL/分鐘，再較佳為100~200mL/分鐘 　　[0063] 3.實施例 　　以下，以本發明實施例來說明，但本發明並不限定於任何此等之實施例。且，本實施例之「份」以及「%」只要沒有特別限制，為質量基準。 　　[0064] 3.1.二氧化矽粒子分散體之製作 ＜二氧化矽粒子分散體A＞ 　　二氧化矽粒子分散體A如以下來製作。於純水787.9g、26%氨水786.0g、甲醇12924g之混合液中，將四甲氧基矽氧烷1522.2g、甲醇413.0g之混合液以將液溫保持在35℃之下以55分鐘滴落，得到將水與甲醇作為液狀介質之二氧化矽溶膠。將此二氧化矽溶膠於常壓下加熱濃縮至5000ml，得到二氧化矽粒子分散體A(二氧化矽含量(固體成分濃度)20質量%，pH7.4，平均粒子徑75nm)。將所得之二氧化矽粒子分散體A使用0.1N氫氧化鈉水溶液，滴定至pH4~9之範圍，由其滴定值與BET比表面積之值算出矽醇基密度後，為5.2個/nm² 。 　　[0065] 將二氧化矽粒子分散體A以離子交換水稀釋至0.01%，1滴載於具有篩孔尺寸為150μm之Cu粒之膠棉膜上，於室溫下乾燥。如此，在Cu粒上不使粒子形狀崩解之狀態調製觀察用之樣品後，使用透過型電子顯微鏡(日立High-Technologies公司製，「H-7650」)以攝影倍率20000倍攝影粒子之影像，測定50個二氧化矽粒子之長徑以及短徑，算出其平均值。由長徑之平均值(Rmax)以及短徑之平均值(Rmin)算出其比(Rmax/Rmin)後，為1.2。 　　[0066] ＜二氧化矽粒子分散體B＞ 　　二氧化矽粒子分散體B如以下來製作。首先，將扶桑化學工業公司製之高純度膠體二氧化矽(產品編號：PL-3；固體成分濃度20質量%，pH7.4，平均粒子徑75nm)35kg與離子交換水140kg置入40L高壓釜，於160℃下0.5小時，並於0.5MPa之加壓下進行水熱處理。接著，將含有前述二氧化矽粒子之分散體水溶液以沸點78℃下減壓濃縮，得到二氧化矽含量(固體成分濃度)20質量%，平均粒子徑74nm，pH7.5之二氧化矽粒子分散體B。將所得之二氧化矽粒子分散體B使用0.1N氫氧化鈉水溶液，滴定至pH4~9之範圍，由其滴定值與BET比表面積之值算出矽醇基密度後，為4.5個/nm² 。由長徑之平均值(Rmax)以及短徑之平均值(Rmin)算出其比(Rmax/Rmin)後，為1.2。 　　[0067] ＜二氧化矽粒子分散體C＞ 　　二氧化矽粒子分散體C如以下來製作。首先，使扶桑化學工業公司製之高純度膠體二氧化矽(產品編號：PL-3；固體成分濃度20質量%，pH7.4，平均粒子徑75nm)5kg與3-硫氫基丙基三甲氧基矽氧烷6g混合，加熱還流2小時後，得到硫醇化二氧化矽溶膠。於此二氧化矽溶膠中添加過氧化氫，藉由使其加熱還流8小時，使表面氧化，得到表面固定化磺酸之膠體二氧化矽。如此，得到二氧化矽含量(固體成分濃度)20質量%，平均粒子徑68nm，pH6.6之二氧化矽粒子分散體C。將所得之二氧化矽粒子分散體C使用0.1N氫氧化鈉水溶液，滴定至pH4~9之範圍，由其滴定值與BET比表面積之值算出矽醇基密度後，為5.7個/nm² 。由長徑之平均值(Rmax)以及短徑之平均值(Rmin)算出其比(Rmax/Rmin)後，為1.3。 　　[0068] ＜二氧化矽粒子分散體D＞ 　　二氧化矽粒子分散體D如以下來製作。添加離子交換水200g、17%鹽酸2g以及矽酸四乙酯(固體成分濃度28質量%)500g。60分鐘後添加純水4000g稀釋，得到約4770g之活性矽酸液(二氧化矽濃度=0.56莫耳/升)。攪拌下添加氫氧化鈉10%水溶液36.4g將pH設為8.0，於95℃下加熱1小時。冷卻後，以超微過濾濃縮，得到膠體二氧化矽。如此，得到二氧化矽含量(固體成分濃度)20質量%，平均粒子徑40nm，pH9.5之二氧化矽粒子分散體D。將所得之二氧化矽粒子分散體D使用0.1N氫氧化鈉水溶液，滴定至pH4~9之範圍，由其滴定值與BET比表面積之值算出矽醇基密度後，為5.7個/nm² 。由長徑之平均值(Rmax)以及短徑之平均值(Rmin)算出其比(Rmax/Rmin)後，為1.7。 　　[0069] 3.2.化學機械研磨用組成物之調製 　　於聚乙稀製容器中添加各成分，使其成為表1或表2所示之含有比例，進一步因應必要添加氫氧化鉀、氫氧化鈉，調整至表1或表2所示之pH，調製各實施例以及各比較例之化學機械研磨用組成物。 　　[0070] 3.3.評價方法 3.3.1.研磨速度評價 　　使用上述所調製之化學機械研磨用組成物，將附有直徑12吋之鈷膜200nm之晶圓與附有直徑12吋之氮化鈦50nm之晶圓分別作為被研磨體，以下述研磨條件進行1分鐘之化學機械研磨試驗。且，於上述說明之第2研磨處理步驟中，作為障壁金屬膜使用氮化鈦之情形較多。如此之情況下，不僅鈷膜之研磨速度，作為與被研磨面共存之障壁金屬膜，氮化鈦膜之研磨速度也非常重要。因此，分別評價鈷膜與氮化鈦膜之研磨速度。 　　[0071] ＜研磨條件＞ ・研磨裝置：G&P TECHNOLOGY公司製，型式「POLI-400L」 ・研磨墊片：富士紡績公司製，「多硬質聚氨基甲酸酯製墊片；H800-type1(3-1S)775」 ・化學機械研磨用組成物供給速度：100mL/分鐘 ・定盤迴轉數：100rpm ・頭部迴轉數：90rpm ・頭部按壓：2psi ・研磨速度(Å/min)=(研磨前之膜之厚度-研磨後之膜之厚度)/研磨時間 　　且，鈷膜或氮化鈦膜之厚度是藉由電阻率測定機(NPS公司製，型式「Σ-5」)並以直流4探針法來測定電阻，自此薄片電阻值與鈷或氮化鈦之體積電阻率並以下述式算出。 　　膜之厚度(Å)=[鈷膜或氮化鈦膜之體積電阻率(Ω･m)÷薄片電阻值(Ω))]×10¹⁰ [0072] 研磨速度評價之評價基準如下述。將其結果合併表示於表1或表2。 ・研磨速度為200Å/min以上時，由於研磨速度較大，故在實際之半導體研磨中，能夠容易確保與其他材料膜之研磨之速度平衡，且較實用，故判斷為良好，並表記為「○」。 ・研磨速度為100Å/min以上且未滿200Å/min時，研磨速度稍微低，故在實際之半導體研磨中，必須要確保與其他材料膜之研磨之速度平衡，但由於能夠實用化，故判斷為良好，並表記為「△」。 ・研磨速度未滿100Å/min時，研磨速度較小，實用困難，故判斷為不良，並表記為「×」。 　　[0073] 3.3.2.腐蝕評價 　　切斷附有直徑12吋之鈷膜200nm之晶圓，製作1×3cm之試驗片，在中央之1×1cm處，以絕緣性膠帶被覆。之後，使用電氣化學測定裝置「HZ-7000(北斗電工股份公司製)」，將試驗片作為作用電極，將鉑(Pt)電極作為背電極，以及將銀氯化銀(Ag/AgCl)電極作為參照電極，將調製之化學機械研磨用組成物作為電解質，製作3極胞。使用如此製作之3極，以線性掃描伏安法(LSV)作成塔菲爾圖，求出腐蝕電流。 ・腐蝕電流為0.001μA以上未滿2μA時，能夠抑制鈷腐蝕，且較實用，故判斷為良好，並表記作「○」。 ・研磨速度為2μA以上未滿100μA時，腐蝕較大，實用上較困難，判斷為不良，並表記作「×」。 　　[0074]

[0075]

[0076] 表1以及表2中，各實施例以及各比較例中的各成分之合計量為100質量份，殘於部分為離子交換水。且，表1以及表2中各成分之簡稱或商品名分別意指以下之成分。 ＜二氧化矽粒子＞ ・DVSTS-027：膠體二氧化矽水分散體(NALCO公司製，商品名「DVSTS-027」 ・DVSTS-028：膠體二氧化矽水分散體(NALCO公司製，商品名「DVSTS-028」 　　[0077] 3.4.評價結果 　　藉由實施例1~8之本案發明相關之化學機械研磨用組成物，能夠一邊抑制鈷膜之腐蝕，一邊在鹼領域中有效率地研磨，並能夠充分地確保良好之研磨特性。另一方面，比較例1~11之化學機械研磨用組成物中，無法使鈷膜之腐蝕抑制與鈷膜之高研磨速度兩立，無法得到良好之研磨特性。 　　[0078] 本發明並不限定於上述實施形態，能夠為各種變形。例如，本發明包含與實施形態所說明之構成實質上相同之構成(例如機能、方法以及結果相同之構成或目的以及效果相同之構成)。且，本發明包含取代實施形態所說明之構成之非本質的部分之構成。且，本發明包含達到與實施形態所說明之構成相同作用效果之構成或能夠達成相同目的之構成。且，本發明包含在實施形態所說明之構成中附加公知技術之構成。For example, as shown in FIG. 1, when an image of an independent silica particle 10a photographed by a transmission electron microscope has an ellipse shape, the long axis a of the ellipse shape is determined as the long axis (Rmax) of the silica particle ), and the short axis b is determined as the short diameter (Rmin) of the silica particles. As shown in FIG. 2, when an image of an independent silica particle 10b photographed by a transmission electron microscope is an aggregate of two primary particles, the longest distance c among the straight lines connecting the end of the image and the end is It is judged as the long diameter (Rmax) of the silica particles, and the shortest diameter d in the straight line connecting the end and the end of the image is judged as the short diameter (Rmin) of the silica particles. As shown in FIG. 3 , when an image of an independent silica particle 10c photographed by a transmission electron microscope is an aggregate of three or more primary particles, the longest distance between the ends of the image and the straight line connecting the ends e is determined as the long diameter (Rmax) of the silica particles, and the shortest diameter f in the straight line connecting the end and the end of the image is determined as the short diameter (Rmin) of the silica particles. [0036] By the above-mentioned determination method, for example, the major axis (Rmax) and the minor axis (Rmin) of 50 silica particles can be measured, and the average value of the major axis (Rmax) and the minor axis (Rmin) can be calculated, Then, it can be obtained by calculating the ratio (Rmax/Rmin) of the average value of the long diameter to the average value of the short diameter. [0037] The content of the silicon dioxide particles is preferably 1 to 20 mass % relative to the total mass of the chemical mechanical polishing composition, more preferably 1 to 15 mass %, and particularly preferably 1 to 10 mass %. When the content ratio of the silica particles is within the aforementioned range, a sufficient polishing rate for the cobalt film can be obtained, and the dispersion stability of the silica particles in the chemical mechanical polishing composition is good. 1.2. Peroxide The chemical mechanical polishing composition related to this embodiment contains peroxide. The peroxide has the function of oxidizing the surface of the cobalt film in the CMP step to form a fragile oxide film. As peroxide, there are ammonium persulfate, potassium persulfate, hydrogen peroxide, iron nitrate (III), ceric ammonium nitrate, iron sulfate, ozone, hypochlorous acid and salts thereof, potassium periodate and As peracetic acid and the like, one or more of these can be used. Among these, hydrogen peroxide is particularly preferred in consideration of oxidizing power, ease of handling, and the like. [0040] The content of the peroxide is relative to the full mass of the chemical mechanical polishing composition, preferably 0.001 to 0.5 mass %, more preferably 0.003 to 0.1 mass %, particularly preferably 0.005 to 0.05 mass %. When the content ratio of the peroxide is within the aforementioned range, the cobalt film is moderately oxidized, so that surface defects are reduced, and a sufficient polishing rate is obtained. 1.3. Content ratio In the chemical mechanical polishing composition related to this embodiment, when the content of silica particles is set as Ma (parts by mass), and the content of peroxides is set as Mb (parts by mass), The value of Ma/Mb is 200 or more and 700 or less, preferably 220 or more and 700 or less, more preferably 250 or more and 680 or less, and particularly preferably 300 or more and 660 or less. If the value of Ma/Mb is within the aforementioned range, the surface of the cobalt film will not be excessively oxidized to cause corrosion, and the chemical reaction of cobalt with the silanol groups existing on the surface of the silica particles and the oxidation reaction of the cobalt film will be multiplied together. The cobalt film can be efficiently polished, and good polishing characteristics can be realized. 1.4. Liquid medium The chemical-mechanical polishing composition related to this embodiment contains a liquid medium. Examples of the liquid medium include water, a mixed medium of water and ethanol, a mixed medium containing water and an organic solvent having compatibility with water, and the like. Among these, it is preferable to use a mixed medium of water, water and ethanol, and it is more preferable to use water. 1.5. Other Components The chemical mechanical polishing composition related to the present embodiment can contain, in addition to the above-mentioned components, an anionic compound having one or more double bonds, a well-known organic acid recorded in Japanese Patent Laid-Open No. 2014-229827, etc. (except for anionic compounds having one or more double bonds), surfactants and other additives. <Anionic compound having one or more double bonds> The chemical mechanical polishing composition according to the present embodiment preferably contains an anionic compound having one or more double bonds. Such anionic compounds can form chelates with cobalt atoms on the surface of the modified cobalt film. As a result, cobalt is eluted from the chemical mechanical polishing composition, and the polishing rate of the cobalt film may increase. [0045] As an anionic compound having one or more double bonds, compounds represented by the following general formulae (1) to (3) are preferred. [Chemical 1]

(In the above general formula (1), R ¹ is an alkyl group or a carboxyl group with 1 to 8 carbon atoms, and R ² represents an organic group or a carboxyl group with a carbon number of 1 to 15 carbon atoms.) [0047] [Chemical 2]

[Chemical 3]

In above-mentioned general formula (2) and above-mentioned general formula (3), R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent hydrogen or an organic group having 1 to 3 carbon atoms of a carboxyl group or a carboxyl group. However, at least one of R ³ and R ⁴ represents an organic group having 1 to 3 carbon atoms or a carboxyl group having a carboxyl group, and at least one of R ⁵ and R ⁶ represents an organic group having 1 to 3 carbon atoms or a carboxyl group having a carboxyl group. Specific examples of anionic compounds having one or more double bonds include maleic acid, butenedioic acid, quinolinic acid, quinalic acid, oleic acid, alkenyl succinic acid, and salts of these. etc., one or more of these can be used. [0051] The content of the anionic compound having one or more double bonds is preferably 0.0001 to 1 mass %, more preferably 0.001 to 0.5 mass %, relative to the total mass of the chemical mechanical polishing composition. When the content ratio of the anionic compound having one or more double bonds is in the aforementioned range, the corrosion of the cobalt film can be suppressed, and the polishing rate of the cobalt film can be improved. 1.6. pH of chemical mechanical polishing composition The pH of the chemical mechanical polishing composition related to this embodiment is preferably 7 or more and 11 or less, more preferably 8 or more and 11 or less, particularly preferably 9 or more and 11 or less. . When the pH is within the aforementioned range, the cobalt film can be polished while the corrosion of the cobalt film is suppressed, so that favorable polishing characteristics can be obtained. On the other hand, if the pH is less than 7, although the polishing rate of the cobalt film is increased, corrosion of the cobalt film is likely to occur, so that it is difficult to obtain good polishing characteristics. [0053] As a means for adjusting the pH of the chemical mechanical polishing composition, there is, for example, a method of adding a base to the chemical mechanical polishing composition. As a base which can be added, ammonia, potassium hydroxide, sodium hydroxide, TMAH (tetramethylammonium hydroxide), etc. are mentioned, for example. These bases can be used alone or in combination of two or more. 1.7. Application The chemical mechanical polishing composition related to this embodiment can achieve the practical polishing speed for the cobalt film as described above, and simultaneously has the corrosion inhibition effect of the cobalt film. Therefore, the chemical mechanical polishing composition according to this embodiment is suitable as a polishing material for chemical mechanical polishing of cobalt films for forming metal wiring, metal gates, and metal plugs in the manufacturing process of semiconductor devices. 1.8. Preparation method of chemical mechanical polishing composition The chemical mechanical polishing composition related to this embodiment can be prepared by dissolving or dispersing the above-mentioned components in a liquid medium such as water. The method for dissolving or dispersing is not particularly limited, and any method can be applied as long as it can be dissolved or dispersed uniformly. In addition, there is no particular limitation on the mixing order or mixing method of the above-mentioned components. [0056] Moreover, the chemical mechanical polishing composition related to this embodiment can be prepared as a concentrated stock solution, and then diluted with a liquid medium such as water during use. 2. Chemical Mechanical Polishing Method The chemical mechanical polishing method related to one embodiment of the present invention includes the step of chemically mechanical polishing the cobalt film using the above-mentioned chemical mechanical polishing composition. Hereinafter, a specific example of the chemical mechanical polishing method according to the present embodiment will be described in detail using drawings. 2.1. Fabrication of the device (object to be processed) FIG. 4 shows the object to be processed 100 used in the chemical mechanical polishing method related to the present embodiment. (1) First, an insulating film 20 is formed on a silicon substrate (not shown) by a plasma CVD method or a thermal oxidation method. As the insulating film 20, a TEOS film etc. are mentioned, for example. (2) On the insulating film 20, the protective film 30 is formed by the CVD method or the thermal oxidation method. As the protective film 30, for example, a SiN film or the like is mentioned. (3) The insulating film 20 and the protective film 30 are etched to form the wiring recess 40 . (4) Using the CVD method or the PVD method, the barrier metal film 50 is formed so as to cover the surface of the protective film 30 and the bottom and inner wall surfaces of the wiring recess 40 . The barrier metal film 50 is preferably Ti or TiN from the viewpoint of excellent adhesion to the cobalt film and excellent diffusion barrier properties to the insulating film and the protective film, but is not limited to these, and may also be Ta, TaN, Mn , Ru et al. (5) Cobalt is deposited on the barrier metal film 50 by the PVD method, the CVD method, or the plating method to form the cobalt film 60 , thereby obtaining the object to be processed 100 . 2.2. Chemical Mechanical Polishing Method Next, the object 100 to be treated is subjected to a two-stage polishing treatment. As the first polishing treatment step, in order to remove the cobalt film 60 deposited on the barrier metal film 50 of the object to be treated 100, the chemical mechanical polishing composition described in Japanese Unexamined Patent Publication No. 2016-30831 and the like which shows a high polishing rate for cobalt is used material for chemical mechanical grinding. By this chemical mechanical polishing, the cobalt film 60 is continuously polished until the protective film 30 or the barrier metal film 50 is exposed on the surface. Usually, after confirming that the protective film 30 or the barrier metal film 50 is exposed on the surface, it is necessary to stop the polishing. Although the polishing rate for the cobalt film is very high, when a chemical mechanical polishing composition that hardly polishes the barrier metal film is used, as shown in FIG. 5 , the chemical mechanical polishing cannot be performed at the point when the barrier metal film 50 is exposed on the surface. , so that the chemical mechanical polishing can be stopped by itself (Self-stop). Next, as the second polishing treatment step, by using the chemical mechanical polishing composition of the present invention, the cobalt film 60, the barrier metal film 50 and the protective film 30 or the insulating film 20 coexist on the surface to be processed, which can The corrosion of the surface of the cobalt film is reduced, and the polishing speed is not reduced. 2.3. Chemical Mechanical Polishing Apparatus In the chemical mechanical polishing method related to the present embodiment, a commercially available chemical mechanical polishing apparatus can be used. Commercially available chemical mechanical polishing apparatuses include, for example, EPO-112, EPO-222, manufactured by EBARA CORPORATION; LGP-510, LGP-552, manufactured by Lapmaster SFT; Company-made, type "Mirra", "Reflexion";G&P TECHNOLOGY company-made, type "POLI-400L", etc. [0062] As the preferred polishing conditions, it should be appropriately set according to the chemical mechanical polishing device used, but for example, when the above-mentioned "EPO-112" is used as the chemical mechanical polishing device, the following conditions can be set.・Number of rotations of the fixed plate; preferably 30~120rpm, more preferably 40~100rpm ・Number of head rotations; preferably 30~120rpm, more preferably 40~100rpm ratio; preferably 0.5~2, more preferably 0.7~1.5 ・grinding pressure; preferably 60~200gf/cm ² , more preferably 100~150gf/cm ²・chemical mechanical polishing composition supply speed; Preferably it is 50～300mL/min, more preferably 100～200mL/min [0063] 3. Examples Below, the embodiments of the present invention are described, but the present invention is not limited to any such embodiments. In addition, "part" and "%" in this example are based on the quality unless there is any particular limitation. 3.1. Preparation of Silica Particle Dispersion <Silica Particle Dispersion A> Silica particle dispersion A was prepared as follows. In a mixed solution of 787.9 g of pure water, 786.0 g of 26% ammonia water, and 12,924 g of methanol, a mixture of 1,522.2 g of tetramethoxysiloxane and 413.0 g of methanol was added to keep the liquid temperature at 35°C for 55 minutes. fall to obtain a silica sol using water and methanol as a liquid medium. The silica sol was heated and concentrated to 5000 ml under normal pressure to obtain silica particle dispersion A (silicon dioxide content (solid content concentration) 20 mass %, pH 7.4, average particle diameter 75 nm). The obtained silica particle dispersion A was titrated with a 0.1N sodium hydroxide aqueous solution to the pH range of 4-9, and the silanol group density was calculated from the titration value and the value of the BET specific surface area, and it was 5.2/nm ² . [0065] The silica particle dispersion A was diluted to 0.01% with ion-exchanged water, 1 drop was loaded on a collodion film with Cu particles with a mesh size of 150 μm, and dried at room temperature. In this way, a sample for observation was prepared in a state in which the shape of the Cu particles was not disintegrated, and then an image of the particles was photographed at a magnification of 20,000 using a transmission electron microscope (manufactured by Hitachi High-Technologies, "H-7650"). The major axis and minor axis of 50 silica particles were measured, and the average value was calculated. The ratio (Rmax/Rmin) was calculated from the average value (Rmax) of the long diameter and the average value (Rmin) of the short diameter, and it was 1.2. <Silica particle dispersion B> The silica particle dispersion B was prepared as follows. First, 35 kg of high-purity colloidal silica (product number: PL-3; solid content concentration 20 mass %, pH 7.4, average particle size 75 nm) manufactured by Fuso Chemical Industry Co., Ltd. and 140 kg of ion-exchanged water were placed in a 40L autoclave , at 160 ° C for 0.5 hours, and under the pressure of 0.5MPa for hydrothermal treatment. Next, the dispersion aqueous solution containing the aforementioned silica particles was concentrated under reduced pressure at a boiling point of 78° C. to obtain a silica particle dispersion with a silica content (solid content concentration) of 20 mass %, an average particle diameter of 74 nm, and a pH of 7.5. body B. The obtained silica particle dispersion B was titrated with a 0.1N sodium hydroxide aqueous solution to a pH range of 4 to 9, and the silanol group density was calculated from the titration value and the value of the BET specific surface area, and it was 4.5 particles/nm ² . The ratio (Rmax/Rmin) was calculated from the average value (Rmax) of the long diameter and the average value (Rmin) of the short diameter, and it was 1.2. <Silica particle dispersion C> The silica particle dispersion C was produced as follows. First, 5 kg of high-purity colloidal silica (product number: PL-3; solid content concentration 20 mass %, pH 7.4, average particle diameter 75 nm) manufactured by Fuso Chemical Industry Co., Ltd. was mixed with 3-sulfhydryl propyl trimethoxy 6 g of siloxane was mixed, and after heating and flowing for 2 hours, a thiolated silica sol was obtained. Hydrogen peroxide was added to the silica sol, and the surface was oxidized by heating and flowing for 8 hours to obtain colloidal silica with surface-immobilized sulfonic acid. In this way, a silica particle dispersion C having a silica content (solid content concentration) of 20 mass %, an average particle diameter of 68 nm, and a pH of 6.6 was obtained. The obtained silica particle dispersion C was titrated with a 0.1N sodium hydroxide aqueous solution to the pH range of 4 to 9, and the silanol group density was calculated from the titration value and the value of the BET specific surface area, and it was 5.7 particles/nm ² . The ratio (Rmax/Rmin) was calculated from the average value (Rmax) of the long diameter and the average value (Rmin) of the short diameter, and it was 1.3. <Silica particle dispersion D> The silica particle dispersion D was produced as follows. 200 g of ion-exchanged water, 2 g of 17% hydrochloric acid, and 500 g of tetraethyl silicate (solid content concentration: 28 mass %) were added. After 60 minutes, 4000 g of pure water was added for dilution to obtain about 4770 g of active silicic acid solution (silicon dioxide concentration = 0.56 mol/liter). With stirring, 36.4 g of a 10% aqueous solution of sodium hydroxide was added to adjust the pH to 8.0, and the mixture was heated at 95°C for 1 hour. After cooling, it was concentrated by ultrafiltration to obtain colloidal silica. In this way, a silica particle dispersion D having a silica content (solid content concentration) of 20 mass %, an average particle diameter of 40 nm, and a pH of 9.5 was obtained. The obtained silica particle dispersion D was titrated with a 0.1N sodium hydroxide aqueous solution to a pH range of 4 to 9, and the silanol group density was calculated from the titration value and the value of the BET specific surface area, and it was 5.7 particles/nm ² . The ratio (Rmax/Rmin) was calculated from the average value (Rmax) of the long diameter and the average value (Rmin) of the short diameter, and it was 1.7. 3.2. The preparation of chemical mechanical polishing composition is added in a polyethylene container, and each component is added to make it become the content ratio shown in Table 1 or Table 2, and potassium hydroxide and sodium hydroxide are further added in response to necessity, The pH was adjusted to the pH shown in Table 1 or Table 2, and the chemical mechanical polishing composition of each Example and each Comparative Example was prepared. 3.3. Evaluation method 3.3.1. Evaluation of polishing speed Using the chemical mechanical polishing composition prepared above, a wafer with a 200 nm cobalt film with a diameter of 12 inches and a 50 nm titanium nitride with a diameter of 12 inches are attached. The wafers were used as objects to be polished, and a chemical mechanical polishing test was performed for 1 minute under the following polishing conditions. In addition, in the second polishing treatment step described above, titanium nitride is often used as the barrier metal film. In such a case, not only the polishing speed of the cobalt film, but also the polishing speed of the titanium nitride film as a barrier metal film coexisting with the surface to be polished is very important. Therefore, the polishing rates of the cobalt film and the titanium nitride film were evaluated respectively. <Polishing conditions> ・Polishing device: G&P TECHNOLOGY Co., Ltd., type "POLI-400L" ・Polishing pad: Fujibo Industries Co., Ltd., "poly-hard polyurethane pad; H800-type1 (3- 1S)775” ・Chemical mechanical polishing composition supply rate: 100mL/min ・Number of rotations of the platen: 100rpm ・Number of rotations of the head: 90rpm ・Head pressing: 2psi ・Polishing speed (Å/min)=(before grinding The thickness of the film - the thickness of the film after polishing)/polishing time, and the thickness of the cobalt film or the titanium nitride film was measured by a resistivity measuring machine (manufactured by NPS, type "Σ-5") with a DC 4 probe The resistance was measured by the method, and the sheet resistance value and the volume resistivity of cobalt or titanium nitride were calculated by the following formula. Film thickness (Å)=[volume resistivity of cobalt film or titanium nitride film (Ω･m)÷sheet resistance value (Ω))]×10 ¹⁰ [0072] The evaluation criteria for polishing speed evaluation are as follows. The results are combined and shown in Table 1 or Table 2.・When the polishing speed is 200Å/min or more, since the polishing speed is relatively large, in actual semiconductor polishing, it is easy to ensure the speed balance of polishing with other material films, and it is more practical, so it is judged as good and marked as " ○”.・When the polishing speed is 100Å/min or more and less than 200Å/min, the polishing speed is slightly lower. Therefore, in the actual semiconductor polishing, it is necessary to ensure a balance between the polishing speed of other material films. However, because it can be practical, it is judged that It is considered to be good, and it is represented by "△".・When the polishing rate is less than 100Å/min, the polishing rate is small and practically difficult, so it is judged as defective and marked with "×". 3.3.2. Corrosion evaluation A wafer with a 200 nm cobalt film having a diameter of 12 inches was cut, and a test piece of 1×3 cm was prepared. The 1×1 cm in the center was covered with an insulating tape. After that, using an electrochemical measuring apparatus "HZ-7000 (manufactured by Hokuto Electric Co., Ltd.)", the test piece was used as the working electrode, the platinum (Pt) electrode was used as the back electrode, and the silver silver chloride (Ag/AgCl) electrode was used as the With reference to the electrode, the prepared chemical mechanical polishing composition was used as an electrolyte to prepare a tripolar cell. A Tafel diagram was created by linear sweep voltammetry (LSV) using the three poles thus produced, and the corrosion current was obtained.・When the corrosion current is 0.001 μA or more and less than 2 μA, cobalt corrosion can be suppressed, and it is practical, so it is judged to be good, and it is marked as “○”.・When the polishing rate is 2 μA or more and less than 100 μA, the corrosion is large and practically difficult, and it is judged as defective and marked with “×”. [0074]

[0075]

In Table 1 and Table 2, the total amount of each component in each embodiment and each comparative example is 100 parts by mass, and the remaining part is ion-exchanged water. In addition, the abbreviation or trade name of each component in Table 1 and Table 2 means the following components, respectively. <Silica particles> ・DVSTS-027: Aqueous colloidal silica dispersion (manufactured by NALCO, trade name "DVSTS-027" ・DVSTS-028: Aqueous colloidal silica dispersion (manufactured by NALCO, trade name ""DVSTS-028" [0077] 3.4. Evaluation Results By the chemical mechanical polishing compositions according to the present invention of Examples 1 to 8, the corrosion of the cobalt film can be suppressed, the polishing can be efficiently performed in the alkali field, and the On the other hand, in the chemical mechanical polishing compositions of Comparative Examples 1 to 11, the corrosion inhibition of the cobalt film and the high polishing rate of the cobalt film could not be balanced, and good polishing characteristics could not be obtained. The present invention is not limited to above-mentioned embodiment, can be various deformations.For example, the present invention includes the structure that is substantially identical with the structure described in the embodiment (for example, the same structure or purpose and effect of function, method and result are identical) In addition, the present invention includes a configuration that replaces the non-essential parts of the configuration described in the embodiment. Furthermore, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same purpose. In addition, the present invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

[0079] 10a, 10b, 10c‧‧‧Silicon dioxide particles 20‧‧‧insulating film 30‧‧‧protective film 40‧‧‧recess for wiring 50‧‧‧barrier metal film 60‧‧‧cobalt film 100‧‧ ‧Subject to be processed

[0018] [FIG. 1] An explanatory diagram schematically showing the concept of a long axis and a short axis of a silica particle. [Fig. 2] An explanatory diagram schematically showing the concept of the long axis and the short axis of the silica particle. [Fig. 3] An explanatory diagram schematically showing the concept of the long axis and the short axis of the silica particle. [Fig. 4] A cross-sectional view schematically showing the object to be processed used in the chemical mechanical polishing method of the present embodiment. [Fig. 5] A cross-sectional view for explaining the polishing step of the chemical mechanical polishing method of the present embodiment.

20‧‧‧Insulating film

30‧‧‧Protective film

40‧‧‧Recess for wiring

50‧‧‧Barrier metal film

60‧‧‧Cobalt film

100‧‧‧Processed object

Claims (7)

A composition for chemical mechanical polishing, which is a composition for chemical mechanical polishing containing silicon dioxide particles and peroxides, wherein the density of silanol groups of the aforementioned silicon dioxide particles is 3-6 pieces/nm ² , and the aforementioned When the content of the silicon particles is Ma (parts by mass) and the content of the above-mentioned peroxides is Mb (parts by mass), the value of Ma/Mb is 200 or more and 700 or less, and the pH is 7 or more and 11 or less. The chemical mechanical polishing composition according to claim 1, wherein the Ma is 3 to 8 parts by mass, and the Mb is 0.005 to 0.01 parts by mass. The chemical mechanical polishing composition according to claim 1 or claim 2, wherein the ratio (Rmax/Rmin) of the long diameter (Rmax) to the short diameter (Rmin) of the silica particles is 1.0 or more and 1.5 or less. The chemical mechanical polishing composition according to claim 1 or claim 2, wherein the peroxide is selected from the group consisting of ammonium persulfate, potassium persulfate, hydrogen peroxide, iron (III) nitrate, ceric ammonium nitrate, iron sulfate, At least one compound from the group consisting of ozone, hypochlorous acid and its salts, potassium periodate and peracetic acid. The chemical mechanical polishing composition according to claim 1 or claim 2, further comprising an anionic compound having one or more double bonds. The composition for chemical mechanical polishing according to claim 1 or claim 2, which is used for chemical mechanical polishing of a cobalt film. A chemical mechanical polishing method, comprising the steps of chemical mechanical polishing of a cobalt film using the chemical mechanical polishing composition according to any one of claim 1 to claim 6.

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