TW200846454A - Polishing composition - Google Patents

Abstract

Disclosed is a polishing composition containing ammonium hydroxide, an ammonium salt and an organic acid, which enables polishing at a higher speed than the conventional compositions. The polishing composition realizes polishing at a still higher speed by additionally containing an oxidizing agent. When the polishing composition further contains an anticorrosive agent, dishing is suppressed. In this polishing agent, an amino acid is preferable as the organic acid, hydrogen peroxide is preferable as the oxidizing agent, and a tetrazole derivative is preferable as the anticorrosive agent. Consequently, there is provided a polishing composition which enables high-speed polishing while suppressing dishing.

Description

200846454 IX. Description of the Invention: TECHNICAL FIELD The present invention relates to an abrasive composition for polishing a metal film, particularly for copper film polishing. [Prior Art]

In order to cope with the demand for high integration and miniaturization of semiconductor integrated circuits (large scaie integrati () n, [si], a method called system-in-package (SIP) has been developed, which is a method. A plurality of semiconductor elements having various functions such as a memory function and a logic function are three-dimensionally mounted on a single substrate. According to the above method, the number of wirings formed on the substrate and the number of bumps increase, and the diameter of each wiring is reduced, and it is difficult to form fine wiring by the build-up method and mechanical polishing by a conventional method. Therefore, copper, copper alloy, or the like having a lower electric resistance is used instead of the previously used wiring material. However, due to its characteristics, copper is difficult to form a wiring pattern of dry-type surnames as in (4), so a wiring formation method called a metal mosaic method is established. For the metal damascene method used in the semiconductor manufacturing process, for example, on the surface of the substrate coated with the second emulsified stone, the groove corresponding to the wiring pattern to be formed is formed and the desired shape is described (4) (4) The electric emulsion connection part of the wiring) After the corresponding hole, in the groove and the hole, == There is titanium, titanium nitride, "Chemical-, crane, etc. barrier gold: film "marginal membrane" Then, by means of an electric clock on the surface of the substrate: the two grooves and the holes are buried in the steel, and then chemical mechanical polishing is used: emiCa (10) such as "1 Ρ〇Η _, CMP" to remove the grooves and holes 129469.doc 200846454 Excess copper film in other areas to form wiring and plug on the surface of the substrate. Similarly, in the SIP, the metal damascene method and CMP can be applied. However, since the film thickness of the metal film such as the copper film coated on the surface of the substrate is more than $, there is a concern that the processing time of the CMP increases and the productivity is greatly deteriorated. . ^ "5" is "grinding in the CMP for the metal layer by the following process, that is, grinding the compound in the acidic region due to the chemical reaction generated on the surface of the 10 metal, so in the CMP for the metal layer The slurry to be used is usually acidic (refer to Japanese Laid-Open Patent Publication No. 2-27-545). However, the acid slurry tends to have a lower polishing rate as the number of polishing sheets increases, and since the alkaline/month washing liquid for removing the abrasive grains after polishing is used, the abrasive particles are affected by pH shock (pH shock). For reasons such as agglutination, it is desirable to use an alkaline slurry that can be ground at a high speed instead of the acidic slurry. φ Further, there is disclosed a polishing method using a slurry which is used as an acid and a basic acid having a pH of 2 to 8, which is an abrasive particle containing hydrogen peroxide, sulfuric acid, nitric acid, and ozone. The oxidizing agent is composed of a pH adjusting agent containing an ammonium group such as ammonia water, ammonium nitrate or ammonium sulfate (refer to International Publication No. 98/54756 pamphlet). Further, the following chemical mechanical polishing method is used, and a polishing liquid for a metal containing at least one of a tetrazole derivative or an anthracene derivative having a specific structure and an oxidizing agent is used (refer to Japanese Laid-Open Patent Publication No. 2006-49790). The contact pressure is set to 1000 to 25000 pa (refer to Japanese Patent Laid-Open No. 129469.doc No. 20084645493580). It is also disclosed that hydrogen peroxide is used as the oxidizing agent, an amino acid is used as the acid, and ammonia is used as the additive or the like. SUMMARY OF THE INVENTION In the case of polishing a copper film by CMP, the slurry described in International Publication No. 98/547% uses an oxidizing agent and a pH adjusting agent containing an ammonium group, but it is difficult to further increase the polishing rate. Further, there is a problem that even if it is known that the south oxidizing power is also increased, the residual ability is improved, and dishing pits are generated in the buried portion of the wiring pattern portion or the like. The polishing liquid for metal described in Japanese Laid-Open Patent Publication No. Hei. No. 2006-49790, the polishing rate of which is at most 1.58 /m/min, in most cases. In the embodiment, it is smaller than i. SUMMARY OF THE INVENTION A first object of the present invention is to provide an abrasive composition which is alkaline and which can achieve a high-speed grinding speed, and a second object is to provide an abrasive composition which can achieve not only a high-speed polishing speed but also a dish-shaped pit. The present invention is an abrasive composition characterized by containing ammonium hydroxide, an ammonium salt and an organic acid. According to the present invention, there is provided an abrasive composition characterized by containing ammonium hydroxide, an ammonium salt and an organic acid. By this, it is possible to obtain a grinding composition which can perform grinding at a higher speed than before. Further, the present invention is an abrasive composition characterized by containing ammonium hydroxide, an ammonium salt and an oxidizing agent. Thereby, an abrasive composition which can be ground at a higher speed than before can be obtained. 129469.doc 200846454 ’ The invention relates to an abrasive composition characterized by comprising a salt, an organic acid and an oxidizing agent. Grinding Abrasive Composition According to the present invention, it is possible to obtain a polishing composition which can be further rotated. Further, the anti-scratch agent is further contained in the polishing composition of the present invention. According to the present invention, it is possible to obtain an abrasive composition which can suppress disc-shaped pits by containing an anti-corrosion agent and can perform grinding at a higher speed. Further, in the polishing composition of the present invention, the organic acid is an amino acid, the oxidizing agent is hydrogen peroxide, and the anticorrosive agent is a tetrasodium derivative. According to the invention, the organic acid is an amino acid, the oxidizing agent is hydrogen peroxide, and the corrosion inhibitor is a tetrazole derivative. Thereby, an abrasive composition which can further suppress the dish-shaped pits and which can be ground at a high speed can be obtained. Also in the polishing composition of the present invention, 卜; 于,于临,西ώ γ ～ Τ The above ammonium salt is selected from the group consisting of ammonium sulfate, ammonium carbonate, ammonium nitrate, ammonium sulfate, - female one stone melon, Asia Ammonium nitrate, sulfite, ammonium bicarbonate, ammonium acetate, B-, and two-deficient ^ ^ ^ one of the narration, ammonium perrhenate, ammonium citrate, ammonium pyrophosphate and ammonium adipate ^ species or more than two. According to the invention, the above-mentioned salt-etchable 1 is used from the ammonium, ammonium carbonate, ammonium nitrate, ammonium sulfate, ammonium disulfate, ammonium sulfite, ammonium sulfite, hydrogen carbonate, ammonium acetate, oxalic acid. Ammonium and peroxoquinone are used in one or more of a + a, sheep L 0 、, ammonium sulphate, coke acid, and ammonium adipate. Further, in the polishing composition of the present invention, the tetrazole derivative is selected from the group consisting of 1H-tetrazole and 5-amino-1H-tetrazole. Tiangan r > branch main 曱 -5-5- thiol-1H-tetrasodium and 1- (2-diethylaminoethyl) _5_1h_ 々 a, l q main one or more. 129469.doc 200846454 According to the present invention, the above tetrazole derivative can be selected from the group consisting of tetrazole, tetradecene and 1-(2-diethylaminoamine-1H-tetrazole, methyl-5-sulfonyl-l-oxime). Base ethyl)-5- 1 Η-four Π φ y y, _ .. one or more of Wang Jia [Embodiment]

The polishing composition of the present invention is suitable for a polishing group of a metal film, particularly a copper film, which can be ground at a higher speed than before by containing hydrogen (10), (iv) and an organic acid. Further, the abrasive composition of the present invention can be milled at a higher speed than previously by containing "molybdenum, salt, and oxidant." Further, the polishing composition of the present invention can be milled at a higher speed than before by containing ammonium hydroxide, an ammonium salt, an organic acid and an oxidizing agent. Further, the dish-shaped pits can be suppressed by containing an anti-corrosion agent. 3 In the abrasive composition of the present invention, the organic acid is preferably an amino acid, the oxidizing agent is preferably hydrogen peroxide, and the anticorrosive is preferably a tetrazole derivative. By this, it is possible to obtain a step-inhibiting dish-shaped pit and to perform high-speed grinding of the composition. Hereinafter, the polishing composition of the present invention will be described in detail. Examples of the ammonium salt contained in the polishing composition of the present invention include ammonium chloride, ammonium carbonate, ammonium nitrate, ammonium sulfate, ammonium disulfate, ammonium nitrite, ammonium sulfite, ammonium hydrogencarbonate, and ammonium acetate. Ammonium oxalate, ammonium peroxylate, ammonium phosphate, ammonium pyrophosphate, ammonium adipate, and the like. Preferred among the ammonium salts are ammonium chloride and ammonium carbonate. In the alkali region, ammonium hydroxide (NH4〇H) is targeted. The wrong person, the action of hydrazine and the oxidizing agent, reacts as in the formula (1) to form a complex. sheet

Cu+ 4NH4+~>[Cu(NH3)4]2+ ··· (1, 129469.doc -10- 200846454 - It is generally believed that in the CMP of copper film, the tetraammine complex is contacted by the polishing pad When it is removed, the polishing is carried out. If an ammonium salt is present in the polishing composition, the anion released from the ammonium salt acts to promote the polishing. - If the ammonium salt is, for example, an amine chloride (NH4C1), the chloride ion is just four. As a result, the copper-copper complex or the copper surface acts, and as a result, even if the load is low, the polishing rate is greatly increased. - Further, the blockage of the polishing pad caused by polishing or the like is suppressed, and the polishing rate can be stabilized and polished. Thus, the ammonium salt not only functions as a polishing accelerator, but also functions as a positive adjusting agent. The ammonium hydroxide content in the polishing composition of the present invention is 1 to 30 of the total amount of the polishing composition. The weight % is preferably 5 to 1% by weight. If the content of ammonium hydroxide is less than 1% by weight and more than 30% by weight, a sufficient polishing rate cannot be obtained. Further, in the abrasive composition of the present invention The ammonium salt content is 〇·1 of the total amount of the abrasive composition When the amount is less than 〇1% by weight, the desired enthalpy value cannot be maintained, and the polishing rate is lowered. If it exceeds 25% by weight, a sufficient polishing rate cannot be obtained. The present invention can be realized by including an organic acid. High-speed polishing rate. Examples of the organic acid contained in the polishing composition of the present invention include amino acid, maleic acid, adipic acid, taurine, oxalic acid, lactic acid, vermiculite & L. etc. Preferred among the specific organic acids are amino acids, maleic acid. The organic acid content in the abrasive composition of the present invention is the total amount of the abrasive composition 129469.doc 200846454..1, wt% Preferably, the polishing rate is lowered by 3 to 8 wt% and the super (four) wt%. Second, the polishing rate is further increased by the inclusion of the emulsifier. ^ is the oxidizing agent contained in the polishing composition, 歹, m : ubiquinone hydrogen, ammonium persulfate, over-burdock & ammonium amide, sodium hypochlorite, etc. The hydrazine emulsifier is preferably hydrogen peroxide. + 忒 并 and 1 ΓΓ hydrogen peroxide, not only can be further realized ^ The grinding speed, 2 and the uniformity is greatly improved. This is because, by adding, it is no longer dependent on the flow of the polishing composition, and the local flow of the polishing composition on the surface of the abrasive is not uniformly ground. 0. K0% by weight of the oxygen in the polishing composition of the present invention, preferably 9 〇" is a total amount of the polishing composition, a good 疋 0.5 to 4.0% by weight. If the oxidizing agent contains % by weight, it is flat. The chemical properties are low; if it exceeds U% by weight, the polishing rate is lowered. In the prior art, 'the pH is adjusted by an ammonium-containing pH-containing agent such as an oxidizing agent such as hydrogen peroxide or ammonium sulfate. The 虱 钿 钿 、 、 、 、 、 , , , , , , , , , , 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 The present invention suppresses the generation of dish-shaped pits by including an organic acid and a preventive agent, and achieves a higher-speed grinding speed than before. By using the organic acid and the anti- _, the surface of the lapping abrasive forms a weak reaction film ‘ while suppressing the etching ability to the surface of the object to be polished. Because &, the surface of the object to be polished which is in contact with the polishing pad is removed, but the bottom of the concave portion of the embedded portion which is not in contact with the polishing pad is not removed, and the unevenness is improved, that is, the intaglio concave 129469.doc • 12 · 200846454 The pit was suppressed. As the organic acid, those exemplified above can be used, and from the viewpoint of suppressing the dish-shaped pits, an amino acid is preferred. Examples of the corrosion inhibitor include a tetrazole derivative, benzimidazole, thiazole, and the like. Preferred among the corrosion inhibitors are tetrazole derivatives. The amino acid contained in the polishing composition of the present invention may, for example, be an acid amino acid containing aspartic acid or a face acid; and an amino acid containing a linear acid or a sulphonic acid. Preferred among the amino acids are aspartic acid which is an acidic amino acid. The content of the amino acid in the polishing composition of the present invention is from 2.0 to 8.0% by weight of the total amount of the polishing composition, preferably from 3 to 7 % by weight. If the content of the amino acid is less than 2.0% by weight and more than 8% by weight, the polishing rate is hardly increased. The tetrazole derivative contained in the polishing composition of the present invention may be exemplified by 1 Η-tetrazole, 5-amino-1 Η-tetrazole, benzyl _5_ thiol_ιη-tetrazole·αΑ1-(2 - Diethylaminoethyl) - 5-1 Η four saliva. Preferred among the tetraterpene derivatives are 1 -tetrazole, 丨_methyl-5-fluorenyl_m_tetrazole, oxime diethylaminoethyl)-5-1Η-tetrazole, especially good. It is 1Η_tetrazole. The anti-content of the abrasive composition towel of the present invention is 研% by weight, preferably 0.25 to 0.75% by weight. If the content of the anti-money agent is less than (% by weight, the dish-shaped pits are not sufficiently suppressed; if it exceeds 1.0% by weight, the polishing rate is drastically lowered. In the grinding composition of the present invention, the enthalpy value is medium The nature and the testability are in the range of 7 to 14, preferably 9 to 1 1. 129469.doc -13 - 200846454 In the polishing composition of the present invention, sufficient effects can be exerted even without the abrasive particles. The abrasive particles may be contained within a range that does not impair the preferred characteristics of the present invention. As the abrasive particles, those commonly used in the art may be used, and for example, sputum cerium oxide (c〇ll〇idal silica) may be mentioned. , fumed silica, fume (j aiumina), fumed alumina, ceria, etc. The abrasive content in the abrasive composition of the present invention is an abrasive composition. The polishing composition of the present invention may further contain a pH adjuster or the like in addition to the above composition. Examples of the acidic component include nitric acid, sulfuric acid, hydrochloric acid, acetic acid, and the like. Alkaline ingredients can be listed Potassium oxide (kappa calcium, lithium hydroxide, etc.) The abrasive composition of the present invention can be contained in various additives commonly used in the polishing composition of the prior art without departing from the scope of its preferred properties. One or two or more kinds of water are used. The water used in the polishing composition of the present invention is not particularly limited, and if it is considered to be used for a semiconductor device, it is preferable to use a step in the step of setting up a temple. For example, , , , 7, ultrapure water, ion-exchanged water, distilled water, etc. The method for producing the polishing composition of the present invention is described below. The polishing composition contains no abrasive particles, but is recorded only by the hydroxide. The salt formed by the salt, the oxygen W, the organic acid, the corrosion inhibitor, and the other additives in the case of water-soluble 1 may be used in an appropriate amount, and the total amount of the composition of 129469.doc •14-200846454 is 100% by weight. In the usual order, the polishing composition is produced by dissolving or dispersing the continuous scent and the four components in water in such a manner as to achieve the desired pH value.

First, the essence is prepared by mixing the salt into the water to make an aqueous solution having a pH adjusted to 7.0 to 9·0, and mixing the organic acid with only the gas ammonium oxide of the double-denier k疋, thereby obtaining Alkaline solution. In the case where the abrasive particles are present, the abrasive particles are adjusted to a specific concentration of 4.0 to 6·0 in the alkali solution to achieve a specific concentration. Further, the test solution was prepared by adding a special anti-insecticide. Finally, by using a solution containing ammonium hydroxide, money salt, organic acid and anti-(4) or an alkali solution containing hydroxide, ammonium salt, organic acid, anti-small agent and abrasive particles, The oxidizing agent of $ obtains the abrasive composition of the present invention. & The abrasive composition of the present invention can be preferably used for the polishing of various metal films in the Lsi manufacturing step, especially in the CMP step when metal wiring is formed by the damascene method, which can be suitably used as a metal film for polishing. Grinding the charge. More specifically, in SIP, it can be suitably used as a metal wiring for laminating a (3) wafer or a copper wiring for a semiconductor device (for forming the copper wiring, it is necessary to polish a copper film having a film thickness of 5 or more) Isochronous metal film polishing slurry. Namely, the composition of the present invention is particularly useful as a metal film polishing composition for a CMP step of a gold damascene method. In addition, as the metal film to be polished, a metal film such as copper or a copper alloy coated on the surface of the odor plate; bismuth, nitriding, zirconia, titanium nitride, tungsten, or the like can be given. Particularly preferred among these are copper metal films. [Examples] 129469.doc -15- 200846454 Hereinafter, examples and comparative examples of the present invention will be described. Examples 1 to 22 of the present invention were produced in the compositions shown in Table 1, respectively.

129469.doc -16· 200846454

-17-129469.doc 200846454 The pH values of Examples 1 to 22 were adjusted to 10.2 by adding an appropriate amount of a pH adjuster (potassium hydroxide). Further, the remainder of Examples 1 to 22 was water. The polishing rates were measured using the above Examples 1 to 22. The evaluation methods of the polishing conditions and the polishing rate are as follows. [Polishing conditions] Substrate to be polished: Φ1 〇〇mm copper-plated substrate polishing device: ECOMET4 (manufactured by BUEHLER) Polishing pad: MH pad (manufactured by Nitta Haas) • Grinding table rotation speed: 200 rpm Carrier rotation speed: 65 rpm Grinding load surface pressure: 70 hPa Flow rate of semiconductor polishing composition: 20 ml/min Grinding time: 60 seconds [grinding speed] The grinding speed is ▲ thickness 晶圆m of the wafer removed by grinding per unit time /min) to indicate. The thickness of the wafer removed by polishing is calculated by measuring the amount of reduction in wafer weight and dividing by the area of the polished surface of the wafer. The results are shown in Table 2. 129469.doc -18- 200846454 [Table 2] Polishing speed Example 1 Example 2 11.6 / / m / min Example 3 4.7 ^ m / min Example 4 6.2 ^ m / min Example 5 7.0 〆 m / min implementation Example 6 20·0 γ m/min Example 7 13.7 ^ m/min Example 8 10.4 "m/min Example 9 13.0//m/min Example 10 6.5 //m/min Example 11 8.8 ^ m /min Example 12 18.6 / / m / min Example 13 11.6 m / min Example 14 15.9 ^ m / min Example 15 15.5 / / m / min Example 16 9.5 " m / min

The polishing liquid for metal described in Japanese Laid-Open Patent Publication No. Hei. No. 2006-93580, the maximum polishing rate is 1.5 8 //m/min, and is less than 1 in most embodiments. /min. On the other hand, the polishing rates of Examples 1 to 16 were all greater than 1.58 //m/min, and the polishing rate was further increased. Further, the etching rates were measured for Examples 17 to 22 containing an anticorrosive agent. The evaluation method of the etching rate is as follows. [Etching speed] The etching rate evaluated refers to a so-called dynamic etching rate when the sample is oscillated in the polishing composition. The samples were impregnated into the abrasive compositions of Examples 17-22 using a 30 mm X 30 mm copper printed substrate under shaking conditions of 23 mm amplitude and 2.2 Hz with a 60 second liquid immersion time. 129469.doc -19- 200846454 The amount of thickness reduction caused by etching is calculated from the thickness of the copper foil before being immersed in the polishing composition and the thickness of the copper foil after the impregnation. The results are shown in Table 3 〇 [Table 3] Residual speed Example 12 7.2 //m/min Example 17 3.4/^m/min Example 18 4.2 ^m/min Example 19 2.7 μτη/πήη Example 20 2 ·9 " m/min Example 21 2.5"m/min Example 22 0.6 μ m/min

For comparison, the residual speed of the embodiment 不含2 containing no anti-money agent is also described. With respect to Examples 17 to 22, it is understood that the etching rate can be lowered by containing an anticorrosive agent. In particular, the etching rate can be greatly reduced by using a tetrazole derivative. If the residual speed is high, dishing pits are likely to occur, so that it is understood that the generation of the dishing pit can be suppressed by lowering the etching rate. Further, the specific polishing rates of Examples 17 to 22 were not exemplified, but all of them were confirmed to be higher than 1 · 58 " in / min 〇 The Example A and the comparative example of the present invention were produced by the following compositions, respectively. (Example A) 2% by weight 10% by weight 1% by weight 5% by weight 0.5% by weight Ammonium hydroxide ammonium salt: Ammonium chloride perhydrogenated hydrochloric acid Amino acid: Aspartic acid tetrazolium derivative: (1H-tetrazole (Comparative Example) 129469.doc -20- 200846454 Ammonium hydroxide 2% by weight Hydrogen peroxide 1wt0/Amidinoic acid: Aspartic acid 5 Weight 0/〇 Siwa Derivative: (1H-Sijun) 〇, 5% by weight The pH values of the examples A and the comparative examples were adjusted to 1 〇·2 by adding an appropriate amount of a pH adjuster (potassium hydroxide). Further, the residual portions of the examples a and the comparative examples were all water.

The comparative example was the same as the composition of Example A except that the ammonium salt (ammonium chloride) was not contained. For the example A and the comparative example, the polishing rate was measured by the above-mentioned polishing conditions and evaluation methods. The results are shown in Table 4. [Table 4] Polishing speed Example A 2·1 "m/min Comparative Example 0.6/^m/min ▲ According to the results shown in Table 4, it was found that the surface pressure of the grinding weight was 7 && The polishing rate of Example A containing ammonium chloride was significantly higher than that of the comparative example containing no vaporized ammonium, which was about 3.5 times. According to the present invention, the present invention can achieve the first objective and high-speed grinding, thereby achieving not only the second object, i.e., the high-speed polishing rate, but also the dishing can be suppressed. The invention may be embodied in a variety of other forms without departing from its spirit or essential characteristics. Therefore, 钿 怨 在 在 在 在 在 在 在 在 在 在 在 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 129 Further, variations or modifications within the scope of the invention are intended to be within the scope of the invention.

129469.doc -22-

Claims (1)

200846454 X. Patent application: It is characterized by containing ammonium hydroxide, ammonium salt and characterized by containing ammonium hydroxide, ammonium salt and oxygen, which are characterized by containing ammonium hydroxide, ammonium salt, and 1 · one abrasive composition Acidic. 2 · A kind of abrasive composition nucleating agent. 3 · - Grinding composition Machine acid and oxidant. 4. The abrasive composition of claim 3, which further contains an anti-corrosion agent. The abrasive composition of item 4, wherein the organic acid is an amino acid, the oxidizing agent is hydrogen peroxide, and the anti-money agent is a tetras-salt derivative. 6. If requested! The abrasive composition, wherein the salt is selected from the group consisting of chlorinated sulphate, carbonic acid, ammonium nitrate, sulphate, disulfide, nitrous acid, ammonium sulfite, ammonium hydrogencarbonate, ammonium acetate, ammonium oxalate, One or more of ammonium oxyacid, ammonium phosphate, ammonium pyrophosphate, and ammonium adipate. 7. The abrasive composition of claim 5, wherein the tetrazole derivative is selected from the group consisting of 1H-tetrazole, 5-amino-1H tetrazole, 丨_mercapto-5-indenyl-ih-tetrazole, and 1- One or more of (2-diethylaminoethyl)-5-1 anthracene-tetrazole. 129469.doc 200846454 VII. Designation of representative drawings: (1) The representative representative of the case is: (none) (2) The symbol of the symbol of the representative figure is simple: Φ 8. If there is a chemical formula in this case, please reveal the characteristics that can best show the invention. Chemical formula: (none) 129469.doc