JPH1174237A - Polishing liquid for copper metal - Google Patents
Polishing liquid for copper metalInfo
- Publication number
- JPH1174237A JPH1174237A JP23282597A JP23282597A JPH1174237A JP H1174237 A JPH1174237 A JP H1174237A JP 23282597 A JP23282597 A JP 23282597A JP 23282597 A JP23282597 A JP 23282597A JP H1174237 A JPH1174237 A JP H1174237A
- Authority
- JP
- Japan
- Prior art keywords
- copper
- polishing
- polishing liquid
- acid
- water
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000005498 polishing Methods 0.000 title claims abstract description 105
- 239000010949 copper Substances 0.000 title claims abstract description 81
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 title claims abstract description 80
- 229910052802 copper Inorganic materials 0.000 title claims abstract description 80
- 239000007788 liquid Substances 0.000 title claims abstract description 45
- 239000002184 metal Substances 0.000 title claims abstract description 15
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 15
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims abstract description 66
- 235000006408 oxalic acid Nutrition 0.000 claims abstract description 22
- 239000006061 abrasive grain Substances 0.000 claims abstract description 21
- 150000007524 organic acids Chemical class 0.000 claims abstract description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 16
- 239000004094 surface-active agent Substances 0.000 claims abstract description 10
- 239000007800 oxidant agent Substances 0.000 claims abstract description 9
- LOAUVZALPPNFOQ-UHFFFAOYSA-N quinaldic acid Chemical compound C1=CC=CC2=NC(C(=O)O)=CC=C21 LOAUVZALPPNFOQ-UHFFFAOYSA-N 0.000 claims abstract description 9
- 239000002270 dispersing agent Substances 0.000 claims abstract description 6
- 150000004699 copper complex Chemical class 0.000 claims description 24
- 229910000881 Cu alloy Inorganic materials 0.000 abstract description 20
- 239000004065 semiconductor Substances 0.000 abstract description 16
- 239000000758 substrate Substances 0.000 abstract description 11
- 239000000203 mixture Substances 0.000 abstract description 4
- DZZMZMCAMYECBC-UHFFFAOYSA-N N1=C(CC(=O)O)C=CC2=CC=CC=C12.N1=C(C=CC2=CC=CC=C12)C(=O)O Chemical compound N1=C(CC(=O)O)C=CC2=CC=CC=C12.N1=C(C=CC2=CC=CC=C12)C(=O)O DZZMZMCAMYECBC-UHFFFAOYSA-N 0.000 abstract 1
- 150000004677 hydrates Chemical class 0.000 abstract 1
- 150000001455 metallic ions Chemical class 0.000 abstract 1
- 238000005530 etching Methods 0.000 description 13
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 8
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 229910021645 metal ion Inorganic materials 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 229910001431 copper ion Inorganic materials 0.000 description 3
- PTVDYARBVCBHSL-UHFFFAOYSA-N copper;hydrate Chemical compound O.[Cu] PTVDYARBVCBHSL-UHFFFAOYSA-N 0.000 description 3
- 239000000377 silicon dioxide Substances 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- AZQWKYJCGOJGHM-UHFFFAOYSA-N 1,4-benzoquinone Chemical compound O=C1C=CC(=O)C=C1 AZQWKYJCGOJGHM-UHFFFAOYSA-N 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- QRUDEWIWKLJBPS-UHFFFAOYSA-N benzotriazole Chemical compound C1=CC=C2N[N][N]C2=C1 QRUDEWIWKLJBPS-UHFFFAOYSA-N 0.000 description 2
- 239000012964 benzotriazole Substances 0.000 description 2
- 229910052681 coesite Inorganic materials 0.000 description 2
- 239000008119 colloidal silica Substances 0.000 description 2
- 230000009918 complex formation Effects 0.000 description 2
- 229910052906 cristobalite Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000007654 immersion Methods 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 235000012239 silicon dioxide Nutrition 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 229910052682 stishovite Inorganic materials 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910052905 tridymite Inorganic materials 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- WJJMNDUMQPNECX-UHFFFAOYSA-N Dipicolinic acid Natural products OC(=O)C1=CC=CC(C(O)=O)=N1 WJJMNDUMQPNECX-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 1
- 229910004541 SiN Inorganic materials 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 150000001735 carboxylic acids Chemical class 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 150000001879 copper Chemical class 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- MVFCKEFYUDZOCX-UHFFFAOYSA-N iron(2+);dinitrate Chemical compound [Fe+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MVFCKEFYUDZOCX-UHFFFAOYSA-N 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000007517 polishing process Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- UBDIMPWXBMWVTC-UHFFFAOYSA-N quinoline-2-carboxylic acid Chemical compound C1=CC=CC2=NC(C(=O)O)=CC=C21.C1=CC=CC2=NC(C(=O)O)=CC=C21 UBDIMPWXBMWVTC-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Grinding-Machine Dressing And Accessory Apparatuses (AREA)
- Weting (AREA)
- Mechanical Treatment Of Semiconductor (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、半導体素子の製造
に用いられる銅系金属用研磨液に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing liquid for a copper-based metal used for manufacturing a semiconductor device.
【０００２】[0002]
【従来の技術】半導体装置の製造工程の一つである配線
層形成においては、表面の段差を解消する目的でエッチ
バック技術が採用されている。このエッチバック技術
は、図３に示すように半導体基板Ｗ上の絶縁膜１に配線
形状の溝２を形成し、前記溝２を含む前記絶縁膜１上に
拡散防止膜３、銅膜４を堆積し、前記銅膜４を研磨装置
および研磨液を用いて研磨処理し、前記溝２内のみに銅
膜４を残存させて埋め込み配線層を形成する方法であ
る。2. Description of the Related Art In forming a wiring layer, which is one of the manufacturing steps of a semiconductor device, an etch-back technique is employed for the purpose of eliminating a step on a surface. In this etch-back technique, as shown in FIG. 3, a wiring-shaped groove 2 is formed in an insulating film 1 on a semiconductor substrate W, and a diffusion prevention film 3 and a copper film 4 are formed on the insulating film 1 including the groove 2. In this method, the copper film 4 is deposited and polished using a polishing apparatus and a polishing liquid, and the copper film 4 is left only in the trench 2 to form a buried wiring layer.
【０００３】ところで、前記研磨液としては従来よりコ
ロイダルシリカのような研磨砥粒が分散された純水から
なるものが用いられている。しかしながら、前記研磨液
を研磨装置の研磨パッドに供給して半導体基板Ｗ上に成
膜された銅膜４を前記研磨パッドに所定の加重を与えな
がら研磨する場合には、単に前記研磨砥粒と研磨パッド
による機械的な研磨が前記銅膜４になされるのみであ
る。したがって、研磨速度が１０ｎｍ／分と低いという
問題があった。Meanwhile, as the polishing liquid, a liquid made of pure water in which polishing grains such as colloidal silica are dispersed has been used. However, when the polishing liquid is supplied to a polishing pad of a polishing apparatus and the copper film 4 formed on the semiconductor substrate W is polished while applying a predetermined load to the polishing pad, the polishing liquid is simply added to the polishing abrasive grains. Only the mechanical polishing by the polishing pad is performed on the copper film 4. Therefore, there is a problem that the polishing rate is as low as 10 nm / min.
【０００４】このため、研磨速度を高めるための以下に
示すようにエッチングを行いながら研磨する技術が開発
されている。例えば、Ｊ．Ｍ．Ｓｔｅｉｇｅｒｗａｌ
ｄ，Ｒ．Ｊ．Ｇａｔｍａｎｎ，Ｓ．Ｐ．Ｍｕｒａｒｋａ
らが、アミン系コロイダルシリカのスラリーまたはＫ3
Ｆｅ（ＣＮ）6 、Ｋ4 （ＣＮ）6 、Ｃｏ（ＮＯ3 ）2 が
添加されたスラリーからなる銅膜または銅合金膜の研磨
液が開示されている。For this reason, a technique for polishing while performing etching has been developed as described below to increase the polishing rate. For example, J. M. Steigerwal
d, R.C. J. Gatmann, S .; P. Murarka
Are the amine-based colloidal silica slurry or K3
There is disclosed a polishing liquid for a copper film or a copper alloy film made of a slurry to which Fe (CN) 6, K4 (CN) 6, and Co (NO3) 2 are added.
【０００５】この他、アンモニア水と酸化剤と砥粒との
混合液を用いたものや、硝酸鉄溶液にＢＴＡ（ベンゾト
リアゾル）を添加した溶液と砥粒との混合液を用いたも
のもあった。[0005] In addition, those using a mixed solution of aqueous ammonia, an oxidizing agent and abrasive grains, and those using a mixed solution of a solution obtained by adding BTA (benzotriazole) to an iron nitrate solution and abrasive grains are also used. there were.
【０００６】一方、エッチングのように銅を溶解せず、
銅表面に銅と反応して水に難溶で銅よりも機械的強度の
低い、すなわち脆弱な銅錯体を生成し、これを研磨する
ことにより研磨速度をあげることも考えられている。On the other hand, copper does not dissolve unlike etching,
It is also considered that a copper surface reacts with copper to form a copper complex which is hardly soluble in water and has a lower mechanical strength than copper, that is, a fragile copper complex, which is polished to increase the polishing rate.
【０００７】[0007]
【発明が解決しようとする課題】上記した従来の銅系金
属用研磨液では、次のような問題があった。すなわち、
金属イオンを含む研磨液は、半導体製造工程で使用する
と金属イオンが銅膜４に拡散し、半導体の動作を阻害す
る虞があった。また、エッチング作用のある研磨液はい
わゆるディッシングを起こす虞があった。すなわち、エ
ッチング作用のある研磨液では浸漬時と研磨時との間で
銅膜４のエッチング速度に差がない。その結果、エッチ
バック工程後において前記溝２内の銅膜４は研磨液に接
触されると、浸漬時と研磨時との間で銅膜４のエッチン
グ速度に差がないため、前記銅膜４がさらに前記研磨液
によりエッチングされる。したがって、前記溝２内の銅
膜４の表面位置が前記絶縁膜１の表面より低くなりへこ
みができるため、前記絶縁膜１の表面と面一の配線層の
形成が困難になり、平坦性が損なわれる。また、形成さ
れた埋め込み銅配線層は、絶縁膜１の表面と面一に埋め
込まれた銅配線層に比べて抵抗値が高くなる。The above-mentioned conventional polishing liquid for copper-based metal has the following problems. That is,
When the polishing liquid containing metal ions is used in the semiconductor manufacturing process, the metal ions may diffuse into the copper film 4 and hinder the operation of the semiconductor. Further, the polishing liquid having an etching action may cause so-called dishing. In other words, there is no difference in the etching rate of the copper film 4 between the time of dipping and the time of polishing with a polishing liquid having an etching action. As a result, when the copper film 4 in the groove 2 is brought into contact with the polishing liquid after the etch-back step, there is no difference in the etching rate of the copper film 4 between the time of immersion and the time of polishing. Is further etched by the polishing liquid. Therefore, since the surface position of the copper film 4 in the groove 2 is lower than the surface of the insulating film 1 and can be dented, it is difficult to form a wiring layer flush with the surface of the insulating film 1 and the flatness is reduced. Be impaired. The formed buried copper wiring layer has a higher resistance value than the copper wiring layer buried flush with the surface of the insulating film 1.
【０００８】一方、脆弱な銅錯体を生成する研磨液で
は、従来の研磨液に比べると高速であるが、エッチング
作用のある研磨液に比べると研磨速度が遅いという問題
があった。On the other hand, a polishing liquid which produces a fragile copper complex has a problem that the polishing speed is higher than that of a conventional polishing liquid, but is lower than that of a polishing liquid having an etching action.
【０００９】そこで本発明は、半導体の動作を阻害する
金属イオンを含まず、かつ、研磨後に配線上部にへこみ
が生じにくいとともに、高速で研磨が可能な銅系金属用
研磨液を提供することを目的としている。SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a polishing solution for copper-based metal which does not contain metal ions which hinder the operation of a semiconductor, does not easily cause dents in the upper portion of wiring after polishing, and can be polished at high speed. The purpose is.
【００１０】[0010]
【課題を解決するための手段】上記課題を解決し目的を
達成するために、請求項１に記載された発明は、銅と反
応して水に難溶性で、かつ銅よりも機械的に脆弱な銅錯
体を生成する水溶性の有機酸とシュウ酸とを含有するよ
うにした。SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and achieve the object, an invention according to claim 1 reacts with copper, is hardly soluble in water, and is mechanically weaker than copper. It contains a water-soluble organic acid and oxalic acid that form a novel copper complex.
【００１１】請求項２に記載された発明は、請求項１に
記載された発明において、上記有機酸は、キナルジン酸
であることとした。請求項３に記載された発明は、請求
項１に記載された発明において、さらに酸化剤を添加し
た。According to a second aspect of the present invention, in the first aspect, the organic acid is quinaldic acid. According to a third aspect of the present invention, in the first aspect of the present invention, an oxidizing agent is further added.
【００１２】請求項４に記載された発明は、請求項１に
記載された発明において、さらに界面活性剤を添加し
た。請求項５に記載された発明は、請求項１に記載され
た発明において、さらに砥粒を添加した。According to a fourth aspect of the present invention, a surfactant is further added to the first aspect of the present invention. According to a fifth aspect of the present invention, in the first aspect, abrasive grains are further added.
【００１３】請求項６に記載された発明は、請求項５に
記載された発明において、さらに砥粒の分散剤を添加し
た。上記手段を講じた結果、次のような作用が生じる。
すなわち、請求項１及び２に記載された発明では、銅と
反応して水に難溶性で、かつ銅よりも機械的に脆弱な銅
錯体を生成する水溶性の有機酸とシュウ酸とを含有する
ようにした。このため、有機酸により銅の水和物（銅イ
オン）と反応して水に難溶性の錯体が生成される。この
銅錯体は、水に溶解されないものの、銅に比べて脆弱で
あるため、研磨処理により容易に研磨することができ、
銅または銅合金を高効率で研磨することができる。一
方、シュウ酸は銅よりも機械的に脆弱な銅錯体を生成す
るとともに銅をエッチングするため、さらに研磨速度を
高めることができる。According to a sixth aspect of the present invention, a dispersant for abrasive grains is further added to the fifth aspect of the invention. As a result of taking the above-described means, the following operation occurs.
In other words, the inventions described in claims 1 and 2 contain a water-soluble organic acid and oxalic acid that react with copper to form a copper complex that is hardly soluble in water and that is more mechanically weaker than copper. I did it. Therefore, the organic acid reacts with copper hydrate (copper ion) to form a complex which is hardly soluble in water. Although this copper complex is not dissolved in water, it is more fragile than copper, so it can be easily polished by a polishing treatment,
Copper or copper alloy can be polished with high efficiency. On the other hand, oxalic acid generates a copper complex that is more mechanically weaker than copper and etches copper, so that the polishing rate can be further increased.
【００１４】また、シュウ酸による銅のエッチングは銅
錯体によって阻止されるため、有機酸とシュウ酸の混合
比を調整することにより、研磨速度を制御することがで
きる。Since the etching of copper by oxalic acid is prevented by the copper complex, the polishing rate can be controlled by adjusting the mixing ratio of the organic acid and oxalic acid.
【００１５】請求項３に記載された発明は、さらに酸化
剤を添加したので、銅錯体の生成を促進させることがで
きる。請求項４に記載された発明は、さらに界面活性剤
を添加したので、銅または銅合金とＳｉＮ膜およびＳｉ
Ｏ2 のような絶縁膜との選択研磨性を高めることが可能
になる。According to the third aspect of the present invention, since an oxidizing agent is further added, the formation of a copper complex can be promoted. In the invention described in claim 4, since a surfactant is further added, copper or a copper alloy, a SiN film and a SiN film are added.
It becomes possible to enhance the selective polishing with an insulating film such as O2.
【００１６】請求項５に記載された発明は、さらに砥粒
を添加したので銅または銅合金表面への損傷を抑制でき
る。請求項６に記載された発明は、さらに砥粒の分散剤
を添加したので、砥粒の凝集を防止することができ、損
傷をさらに抑制することができる。According to the fifth aspect of the invention, since abrasive grains are further added, damage to the copper or copper alloy surface can be suppressed. In the invention described in claim 6, since a dispersant for abrasive grains is further added, aggregation of abrasive grains can be prevented, and damage can be further suppressed.
【００１７】[0017]
【発明の実施の形態】図１は、本発明に係わる銅系金属
用研磨液が適用される研磨装置１０を示す側面図であ
る。この研磨装置１０は、半導体基板Ｗ上に成膜された
銅膜４または銅合金膜４を研磨するものである。FIG. 1 is a side view showing a polishing apparatus 10 to which a polishing liquid for a copper-based metal according to the present invention is applied. The polishing apparatus 10 is for polishing a copper film 4 or a copper alloy film 4 formed on a semiconductor substrate W.
【００１８】ターンテーブル１１上には例えば布から作
られた研磨パッド１２が被覆されている。後述する組成
の銅系金属用の研磨液１７を供給するための供給管１３
は、前記研磨パッド１２の上方に配置されている。上面
に支持軸１４を有する基板ホルダ１５は、研磨パッド１
２の上方に上下動自在でかつ回転自在に配置されてい
る。The turntable 11 is covered with a polishing pad 12 made of, for example, cloth. A supply pipe 13 for supplying a polishing liquid 17 for a copper-based metal having a composition described below.
Is disposed above the polishing pad 12. The substrate holder 15 having the support shaft 14 on the upper surface
2 is arranged so as to be vertically movable and rotatable.
【００１９】このような研磨装置１０において、前記基
板ホルダ１５により半導体基板Ｗをその研磨面（例えば
銅膜４）が前記研磨パッド１２に対向するように保持
し、前記供給管１３から研磨液１７を供給しながら、前
記支持軸１４により前記半導体基板Ｗを前記研磨パッド
１２に向けて所望の加重を与え、さらに前記基板ホルダ
１５および前記ターンテーブル１１を互いに反対方向に
回転させることにより前記半導体基板Ｗ上の銅膜４が研
磨される。In the polishing apparatus 10, the semiconductor substrate W is held by the substrate holder 15 so that the polishing surface (for example, the copper film 4) faces the polishing pad 12. While supplying the semiconductor substrate W to the polishing pad 12 with a desired weight by the support shaft 14, and further rotating the substrate holder 15 and the turntable 11 in opposite directions. The copper film 4 on W is polished.
【００２０】以下、本発明に係る研磨液１７を詳細に説
明する。この銅系金属用研磨液は、銅と反応して水に難
溶な生成物を作る有機酸とシュウ酸とが混合し、酸化
剤、砥粒、界面活性剤、砥粒の分散剤及び水を含有す
る。Hereinafter, the polishing liquid 17 according to the present invention will be described in detail. This copper-based metal polishing liquid is a mixture of oxalic acid and an organic acid that reacts with copper to form a product that is hardly soluble in water, and contains an oxidizing agent, abrasive grains, a surfactant, a dispersant for abrasive grains, and water. It contains.
【００２１】前記有機酸としては、例えばキナルジン酸
（２−キノリンカルボン酸）等を挙げることができる。
キナルジン酸は、銅の水和物（銅イオン）と反応して水
に難溶性の錯体を生成する性質を有する。Examples of the organic acid include quinaldic acid (2-quinolinecarboxylic acid).
Quinaldic acid has a property of reacting with copper hydrate (copper ion) to form a complex which is hardly soluble in water.
【００２２】銅または銅合金の表面に生成された銅錯体
は、水に溶解されにくいものの、銅に比べて脆弱である
ため、研磨処理により容易に研磨される。このため、銅
または銅合金を高効率で研磨することができる。一方、
シュウ酸は銅よりも機械的に脆弱な銅錯体を生成すると
ともに銅をエッチングするため、さらに研磨速度を高め
ることができる。The copper complex formed on the surface of copper or a copper alloy is hardly dissolved in water, but is fragile as compared with copper, and is easily polished by a polishing treatment. Therefore, copper or a copper alloy can be polished with high efficiency. on the other hand,
Oxalic acid generates a copper complex that is more mechanically weaker than copper and etches copper, so that the polishing rate can be further increased.
【００２３】一方、シュウ酸による銅のエッチングはキ
ナルジン酸によって生成された銅錯体によって阻止され
るため、キナルジン酸とシュウ酸の混合比を調整するこ
とにより、研磨速度を制御することができる。On the other hand, since the etching of copper by oxalic acid is prevented by the copper complex generated by quinaldic acid, the polishing rate can be controlled by adjusting the mixing ratio of quinaldic acid and oxalic acid.
【００２４】図２は、本発明の研磨液１７においてシュ
ウ酸の含有量を変えて、基板上に成膜された銅膜を研磨
処理した時の研磨速度（加工速度）をプロットしたもの
である。FIG. 2 is a graph plotting the polishing rate (processing rate) when the copper film formed on the substrate is polished by changing the oxalic acid content in the polishing liquid 17 of the present invention. .
【００２５】本発明の研磨液１７は、有機酸としてキナ
ルジン酸０．６重量％、銅錯体生成促進剤として過酸化
水素６重量％、砥粒５．４重量％、界面活性剤０．９重
量％を混合した水溶液にシュウ酸を添加したものであ
る。The polishing liquid 17 of the present invention contains 0.6% by weight of quinaldic acid as an organic acid, 6% by weight of hydrogen peroxide as a copper complex formation promoter, 5.4% by weight of abrasive grains, and 0.9% by weight of a surfactant. % Oxalic acid was added to an aqueous solution in which oxalic acid was mixed.
【００２６】図２中のαは、上記支持軸１４により研磨
パッド１２に荷重３００ｇ／ｃｍ2を加えたときの特性
線、βは荷重５００ｇ／ｃｍ2 を加えたときの特性線、
γは浸漬時の特性線である。In FIG. 2, α is a characteristic line when a load of 300 g / cm 2 is applied to the polishing pad 12 by the support shaft 14, β is a characteristic line when a load of 500 g / cm 2 is applied,
γ is a characteristic line at the time of immersion.
【００２７】図２から明らかなように研磨液中のシュウ
酸の含有量が多くなるに従って銅の研磨速度が増大する
ことがわかる。つまり、シュウ酸は銅のエッチング効果
がある。また、さらに酸化剤のような銅錯体生成促進剤
を含有する前記研磨液は、銅錯体の生成が促進され、研
磨時において銅または銅合金を従来の研磨砥粒のみを含
有する研磨液と比べて高速に研磨することが可能にな
る。As is clear from FIG. 2, the polishing rate of copper increases as the content of oxalic acid in the polishing liquid increases. That is, oxalic acid has an effect of etching copper. Further, the polishing liquid containing a copper complex formation accelerator such as an oxidizing agent further promotes the formation of a copper complex, and makes the copper or copper alloy more polished during polishing than a polishing liquid containing only conventional polishing abrasive grains. It is possible to polish at high speed.
【００２８】研磨砥粒は、シリカ等の材料から作られ
る。このような研磨砥粒を含む研磨液により銅または銅
合金の研磨処理を行うと、銅または銅合金表面への損傷
を抑制できる。また、砥粒の分散剤が添加されているの
で砥粒の凝集を防止することができ、損傷をさらに抑制
することができる。The abrasive grains are made of a material such as silica. When the copper or copper alloy is polished with a polishing liquid containing such polishing abrasive grains, damage to the copper or copper alloy surface can be suppressed. In addition, since the abrasive dispersant is added, aggregation of the abrasive grains can be prevented, and damage can be further suppressed.
【００２９】酸化剤は、例えば過酸化水素（Ｈ2 Ｏ2 ）
等を用いることができる。酸化剤は銅錯体の生成を促進
させることができる。なお、過酸化水素水は研磨パット
および研磨液中の研磨砥粒による機械的な研磨過程で露
出する下地の銅または銅合金が速やかに脆弱な性質を有
する銅錯体を生成するものと考えられる。The oxidizing agent is, for example, hydrogen peroxide (H 2 O 2)
Etc. can be used. The oxidizing agent can promote the formation of a copper complex. It is considered that the hydrogen peroxide solution rapidly forms a copper complex having a fragile property in the underlying copper or copper alloy exposed during the mechanical polishing process by the polishing pad and the abrasive grains in the polishing liquid.
【００３０】界面活性剤は、銅または銅合金とＳｉＮ膜
およびＳｉＯ2 のような絶縁膜との選択研磨性を高める
ことが可能になる。したがって、本実施の形態に係る研
磨液１７はシュウ酸により銅または銅合金をエッチング
することで高能率に研磨を行うとともに、キナルジン酸
により銅錯体を生成することでエッチングを抑制しなが
ら脆弱な銅錯体を研磨して従来よりも高速度で研磨を行
うことができる。The surfactant can enhance the selective polishing of copper or a copper alloy with an SiN film or an insulating film such as SiO 2. Therefore, the polishing liquid 17 according to the present embodiment performs high-efficiency polishing by etching copper or a copper alloy with oxalic acid, and suppresses etching by forming a copper complex with quinaldic acid, thereby suppressing fragile copper. By polishing the complex, polishing can be performed at a higher speed than before.
【００３１】なお、研磨液１７において、界面活性剤を
添加することによって、研磨時において銅膜・銅合金膜
４とＳｉＯ2 のような絶縁膜２との選択研磨性を高める
ことができる。The addition of a surfactant to the polishing liquid 17 can enhance the selective polishing of the copper film / copper alloy film 4 and the insulating film 2 such as SiO2 during polishing.
【００３２】さらに、界面活性剤が含有する研磨液を用
いることにより、前記エッチバック工程において銅膜・
銅合金膜４からなる配線材料膜とＳｉＯ2 のような絶縁
膜２との選択研磨性を高めることができる。Further, by using a polishing liquid containing a surfactant, a copper film and
The selective polishing of the wiring material film made of the copper alloy film 4 and the insulating film 2 such as SiO2 can be improved.
【００３３】その結果、下地の絶縁膜の膜減り（シンニ
ング）を抑制でき、絶縁耐圧の高い半導体装置を製造す
ることが可能になる。また、このような界面活性剤を含
む研磨液を用いることによって、前記エッチバック工程
後の洗浄において前記絶縁膜上に残留した微細な配線材
料および有機物等の汚染物質を容易に除去することが可
能になる。その結果、絶縁膜表面の有機物や残留配線材
料が除去された清浄な表面を有する半導体装置を製造す
ることができる。As a result, thinning of the underlying insulating film can be suppressed, and a semiconductor device having a high withstand voltage can be manufactured. In addition, by using a polishing liquid containing such a surfactant, it is possible to easily remove contaminants such as fine wiring materials and organic substances remaining on the insulating film in cleaning after the etch-back step. become. As a result, it is possible to manufacture a semiconductor device having a clean surface from which organic substances and residual wiring materials on the surface of the insulating film have been removed.
【００３４】上述したように本実施の形態に係る銅系金
属用研磨液では、半導体の動作を阻害する金属イオンを
含まず、かつ、研磨後に配線上部にへこみが生じにくい
とともに、高速で研磨が可能となる。As described above, the polishing liquid for a copper-based metal according to the present embodiment does not contain metal ions that hinder the operation of the semiconductor, does not easily cause dents in the upper portion of the wiring after polishing, and can be polished at high speed. It becomes possible.
【００３５】なお、本発明に係わる研磨液においてキナ
ルジン酸以外の銅と反応して水に難溶性で、かつ銅より
も機械的に脆弱な銅錯体を生成する水溶性の有機酸とし
て２−ピリジンカルボン酸、２，６−ピリジンカルボン
酸、キノン等を用いた場合でも同様の効果を得ることが
できる。なお、本発明は前記実施の形態に限定されるも
のではなく、本発明の要旨を逸脱しない範囲で種々変形
実施可能であるのは勿論である。In the polishing liquid according to the present invention, 2-pyridine is used as a water-soluble organic acid which reacts with copper other than quinaldic acid to form a copper complex which is hardly soluble in water and mechanically weaker than copper. Similar effects can be obtained even when carboxylic acid, 2,6-pyridinecarboxylic acid, quinone, or the like is used. It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.
【００３６】[0036]
【発明の効果】請求項１及び２に記載された発明によれ
ば、有機酸により銅の水和物（銅イオン）と反応して水
に難溶性の錯体が生成される。この銅錯体は、水に溶解
されないものの、銅に比べて脆弱であるため、研磨処理
により容易に研磨することができ、銅または銅合金を高
効率で研磨することができる。一方、シュウ酸は銅より
も機械的に脆弱な銅錯体を生成するとともに銅をエッチ
ングするため、さらに研磨速度を高めることができる。According to the first and second aspects of the present invention, an organic acid reacts with copper hydrate (copper ion) to form a water-insoluble complex. Although this copper complex is not dissolved in water, it is brittle compared to copper, so that it can be easily polished by a polishing treatment, and copper or a copper alloy can be polished with high efficiency. On the other hand, oxalic acid generates a copper complex that is more mechanically weaker than copper and etches copper, so that the polishing rate can be further increased.
【００３７】また、シュウ酸による銅のエッチングは銅
錯体によって阻止されるため、有機酸とシュウ酸の混合
比を調整することにより、研磨速度を制御することがで
きる。Since the etching of copper by oxalic acid is prevented by the copper complex, the polishing rate can be controlled by adjusting the mixture ratio of the organic acid and oxalic acid.
【００３８】請求項３に記載された発明によれば、銅錯
体の生成を促進させることができる。請求項４に記載さ
れた発明によれば、銅または銅合金とＳｉＮ膜およびＳ
ｉＯ2 のような絶縁膜との選択研磨性を高めることが可
能になる。According to the third aspect of the invention, the formation of a copper complex can be promoted. According to the invention described in claim 4, copper or copper alloy, SiN film and S
It becomes possible to enhance the selective polishing with an insulating film such as iO2.
【００３９】請求項５に記載された発明によれば、銅ま
たは銅合金表面への損傷を抑制できる。請求項６に記載
された発明によれば、砥粒の凝集を防止することがで
き、損傷をさらに抑制することができる。According to the invention described in claim 5, damage to the copper or copper alloy surface can be suppressed. According to the invention described in claim 6, agglomeration of abrasive grains can be prevented, and damage can be further suppressed.
【図１】本発明の一実施の形態に係る銅系金属用研磨液
が適用される研磨装置を示す側面図。FIG. 1 is a side view showing a polishing apparatus to which a polishing liquid for a copper-based metal according to an embodiment of the present invention is applied.
【図２】同銅系金属用研磨液に添加するシュウ酸添加量
と研磨速度との関係を示す図。FIG. 2 is a view showing the relationship between the amount of oxalic acid added to the polishing liquid for a copper-based metal and the polishing rate.
【図３】半導体埋込配線を示す断面図。FIG. 3 is a sectional view showing a semiconductor embedded wiring.
１０…研磨装置 １１…ターンテーブル １２…研磨パッド １５…基板ホルダ １７…銅系金属用研磨液 DESCRIPTION OF SYMBOLS 10 ... Polishing apparatus 11 ... Turntable 12 ... Polishing pad 15 ... Substrate holder 17 ... Polishing liquid for copper metal
Claims (6)
機械的に脆弱な銅錯体を生成する水溶性の有機酸とシュ
ウ酸とを含有することを特徴とする銅系金属用研磨液。1. A copper-based metal comprising a water-soluble organic acid and oxalic acid which react with copper to form a copper complex which is hardly soluble in water and which is mechanically more brittle than copper. Polishing liquid.
特徴とする請求項１に記載の銅系金属用研磨液。2. The polishing liquid according to claim 1, wherein the organic acid is quinaldic acid.
請求項１に記載の銅系金属用研磨液。3. The polishing liquid according to claim 1, further comprising an oxidizing agent.
する請求項１に記載の銅系金属用研磨液。4. The copper-based metal polishing liquid according to claim 1, further comprising a surfactant.
求項１に記載の銅系金属用研磨液。5. The polishing liquid according to claim 1, further comprising abrasive grains.
とする請求項５に記載の銅系金属用研磨液。6. The polishing liquid according to claim 5, further comprising a dispersant for abrasive grains.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23282597A JPH1174237A (en) | 1997-08-28 | 1997-08-28 | Polishing liquid for copper metal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23282597A JPH1174237A (en) | 1997-08-28 | 1997-08-28 | Polishing liquid for copper metal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH1174237A true JPH1174237A (en) | 1999-03-16 |
Family
ID=16945379
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23282597A Pending JPH1174237A (en) | 1997-08-28 | 1997-08-28 | Polishing liquid for copper metal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH1174237A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001085374A (en) * | 1999-07-13 | 2001-03-30 | Kao Corp | Abrasive liquid composition |
| KR100939404B1 (en) | 2001-12-28 | 2010-01-28 | 후지코시 기카이 고교 가부시키가이샤 | Copper layer polishing method of substrate |
| JP2010166087A (en) * | 2010-04-12 | 2010-07-29 | Jsr Corp | Aqueous dispersion for chemical mechanical polishing |
| CN103128633A (en) * | 2013-02-21 | 2013-06-05 | 宁夏丰兆科技发展有限公司 | Magnesium plate polishing machine |
-
1997
- 1997-08-28 JP JP23282597A patent/JPH1174237A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001085374A (en) * | 1999-07-13 | 2001-03-30 | Kao Corp | Abrasive liquid composition |
| JP4614497B2 (en) * | 1999-07-13 | 2011-01-19 | 花王株式会社 | Polishing liquid composition |
| KR100939404B1 (en) | 2001-12-28 | 2010-01-28 | 후지코시 기카이 고교 가부시키가이샤 | Copper layer polishing method of substrate |
| JP2010166087A (en) * | 2010-04-12 | 2010-07-29 | Jsr Corp | Aqueous dispersion for chemical mechanical polishing |
| CN103128633A (en) * | 2013-02-21 | 2013-06-05 | 宁夏丰兆科技发展有限公司 | Magnesium plate polishing machine |
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