TW589678B - Chemical mechanical polishing process for non-dishing at narrow lines in Cu process - Google Patents

Abstract

A chemical mechanical polishing (CMP) process for non-dishing at narrow lines in Cu process is disclosed. After removing the surplus Cu and barrier material, a CMP step is performed to remove a portion of a barrier layer and an anti-reflect coating (ARC) at an open edge. The aforementioned CMP step uses the slurry mixing with a slurry used to remove the barrier layer and a slurry used to remove the ARC. Then, another CMP step is performed to remove the residual ARC on a dielectric layer by using the aforementioned slurry used to remove the ARC.

Description

589678

The invention relates to a chemical mechanical polishing process (CMP process) in a copper process, and more particularly to a chemical mechanical polishing process in a copper process that prevents thin wire dishing. Background of the invention:. With the rapid development of the integrated circuit manufacturing process, the delay in resistance (reS1Stivity capacitance; Rc) caused by the metal connecting wire seriously affects the speed of component operation. The method to improve the RC delay is to use a low dielectric constant material as the insulation layer between the multilayer metal connection lines to reduce the parasitic capacitance between the metal layers, or use a low-resistance metal material such as copper metal. After forming the copper metal layer and the low-dielectric-constant dielectric layer, it is necessary to remove the deposited layer on the surface. Generally, chemical mechanical polishing can be used for planarization. Chemical mechanical polishing method, referred to as CMP for short, is a technology that can be used for comprehensive planarization in integrated circuit manufacturing processes. It uses a chemical grinding principle similar to the "grinding knife" and the chemical reaction provided by appropriate chemical additives. 'Wafer and fluctuate the contours of the wafer surface and smooth them. In the chemical mechanical polishing process', usually the slurry is used to refer to the chemical additives used. Generally, the polishing slurry used in chemical mechanical polishing is mainly based on Colloidal silica (silica) or dispersed alumina (aluminum), and testability 2 1 $ This paper size applies Chinese National Standard (CNS) A4 specifications (2ΐ〇χ 297 public love) ... ....... I < Please read the notes on the back before filling out this page) Order Φ Printed by the Intellectual Property Bureau Employee Consumer Cooperative of the Ministry of Economic Affairs 589678 Printed by the Employee Consumer Cooperative of the Ministry of Economic Affairs Intellectual Property Bureau Printed A7 B7 V. Invention The solution of () potassium nitrate (K0H) or ammonium hydroxide (NH4OH) and other solutions. Pan Shicheng. The Shi Xi as the dagger δ and the soil originally used the above-mentioned extremely hard abrasive particles. Surface In addition, the composition of the polishing slurry also includes some chemical agents or organic solvents to perform the chemical mechanical polishing process in the chemical mechanical polishing process. In the second copper removal process, the chemical mechanical polishing is used to flatten the wafer surface. It is prone to dishing as shown in Figure 1. Please refer to Figure 1 'to form a low-k dielectric layer 12 on the substrate 10. Then, form an interconnect or metal pad in it. The copper metal layer 16 is used, and a barrier layer 1 * is formed between the steel metal layer 16 and the low-dielectric-constant dielectric layer 12 to prevent the diffusion of the steel metal material. The purpose of the chemical mechanical polishing step is to remove ☆ "Excessive deposited layers on the electrical layer 12, such as excess copper metal materials, low dielectric constant and anti-reflection coating (not shown) materials, etc. However, after the chemical mechanical polishing step, the dishing phenomenon 18 of the copper metal layer 16 often occurs in the grooves of the green metal. Such discs and phenomena may cause device failure in subsequent integrated circuit bypass tests such as VBD, TDDB, and leakage current. 7 Purpose and summary of the invention: In view of the above background of the invention, in the chemical mechanical grinding of copper metal materials, the dish erosion phenomenon easily occurs and affects the subsequent social test results. Therefore, one of the objects of the present invention is to provide a The wind generator in the steel process 3 11 ^ 11 ---.------, 1 bite (Please read the precautions on the back before filling this page)

589678 Α7 B7 V. Description of the invention (The mechanical grinding process can prevent the conventional phenomenon. The copper metal dish corrosion appearing in the wire According to the above-mentioned purpose, the transformation of the thin wire dish erosion phenomenon of the hair A ^ The chemical-mechanical grinding process of preventing copper from being made privately in copper includes two mechanical grinding steps, using a first grinding: grinding to remove part of the barrier layer, and then performing the first step, mixing the second above; —Chemical-mechanical polishing step ^ The polishing slurry and another third polishing slurry are used to remove the anti-reflection coating layer and the barrier layer of the part VIII. 77 waste n part of the anti-reflection coating layer and the barrier layer removed It is in contact with a pipe flute "" Follows the edge of the trough 4 tr (h_h); and, further into the mechanical grinding step, the third polishing slurry mentioned above is used to remove the anti-reflective coating remaining on the surface of the dielectric layer 〃: Invented the chemical-mechanical grinding of the thin wire and discs in the process of inventing steel. The first chemical-mechanical grinding step described above can remove some of the copper material first, and then use another high-selective grinding paddle to remove the excess of the groove surface. Copper metal material. The material of the above barrier layer is generally composed of tantalum nitride, titanium nitride, or titanium nitride button, and the anti-reflection coating layer is generally composed of oxide. In addition, the above-mentioned first grinding The mounting system uses a pair of steel: two slurry with high selectivity to the removal rate, and the second slurry and the third slurry have higher removal rates for the barrier layer and the anti-reflection coating layer. After the third mechanical grinding step, a protective layer can be formed on the surface due to the interaction between the components in the grinding slurry and the steel metal, so that the copper metal layer can be protected from abrasion during the subsequent chemical mechanical grinding process to change the paper size Applicable to China National Standard (CNS) A4 specification (21 × 297 mm) Order § Printed by the Employee Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economy 589678 A7

V. Description of the invention () Know well the phenomenon of thin wires and disks. Brief description of the drawings: The preferred embodiment of the present invention will be described in more detail in the following explanatory text with the following figures, in which: FIG. 1 is a schematic diagram showing the structure of the dishing phenomenon of the copper metal material ; And FIG. 2 to FIG. 7 are schematic diagrams showing a method for reducing the depression of the sidewall of the dielectric material in the steel process of the present invention. .......... 0 ^: (Please read the precautions on the back before filling out this page) Printed circle number comparison instructions for employees ’cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs: 10 Substrate 12 Low dielectric constant Electrical layer 14 Barrier layer 16 Copper metal layer 18 Dish phenomenon 40 Substrate 42 Dielectric layer 44 Anti-reflective coating layer 44a Anti-reflective coating layer 46 Barrier layer 46a Barrier layer 48 Steel metal layer 48a Copper metal layer 48b Copper metal layer 50 position Η thickness Detailed description of the invention: Order

I This paper size applies to China National Standard (CNS) A4 (210X297 mm) 589678 A7 B7

V. Description of the invention () It is unclear that it is a kind of ~ tr, I {Please read the precautions on the back before filling this page} Chemical mechanical polishing process. Figure 2 shows a schematic diagram of the front section of a copper metal interconnect typically formed in integrated circuits. Referring to FIG. 2, the first husband forms a dielectric layer 42 made of a low dielectric constant material on the substrate 40, and then forms an anti-reflection coating layer 44 on the dielectric layer 42. Subsequently, a trench is formed at a predetermined position of the metal wiring in the piezoelectric layer 42, and a copper metal layer 48 is formed on the dielectric layer 42 to fill the trench. In order to avoid the diffusion effect of the surface metal material, a barrier layer 46 may be formed between the copper metal layer 48 and the dielectric layer 42. Among them, the general barrier layer 46 is composed of a nitride button, titanium nitride, or titanium nitride button, and the antireflection coating layer 44 is composed of an oxide, but the present invention is not limited thereto. -Customized · Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs After forming the structure as shown in Figure 2, a subsequent chemical mechanical grinding process must be performed to remove unwanted deposits. Referring to FIG. 3, a chemical mechanical polishing step is performed first. Most of the copper metal layer 48 can be removed by a grinding process or a slurry having a faster grinding rate, and a copper metal layer 48a having a thickness h less than about 2000 A is formed. The preferred thickness is between about 2,000 and A. Next, another highly selective polishing t with a copper metal material, a barrier layer and an anti-reflection coating layer with a preferred polishing rate of about 4G: 1: i is adjusted. The excess copper metal material beyond the surface of the opening is removed to form a copper metal layer as shown in the figure. Wherein, the present invention divides the above-mentioned steps of removing the excess copper metal material beyond the opening surface into two process steps as shown in FIG. 3 and FIG. 4, which are based on the Chinese National Standard (CNS) A4 specification of this paper standard, which looks like 297 public directors. ) -------- 589678 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the Invention (The grinding time and cost of the copper metal material is a preferred embodiment. Although selective grinding slurry and other methods can achieve the purpose of removing copper metal materials, it may take more process time and cost, but the present invention is not limited to this. Next, please refer to FIG. 5 to perform another chemical mechanical grinding step The preferred polishing rate with a copper metal material, a barrier layer and an anti-reflection coating layer is about 1: 2: 1, or the polishing rate is faster and larger, such as about 丨: 3: 1 or 1: 4: 1 to remove a portion of the barrier layer 46 to form a barrier layer 46a. The selection of the polishing rate of the above-mentioned polishing slurry may be changed according to production and process requirements, and the present invention is not limited thereto. Subsequently, This invention will The polishing slurry used for removing part of the barrier layer 46 is mixed with the polishing slurry used for subsequent removal of the anti-reflection coating layer to simultaneously remove part of the barrier layer 46 a and part of the anti-reflection coating at the groove edge position 50. Layer 44. Among them, the preferred polishing rate of the copper metal material, the barrier layer, and the anti-reflection coating layer for the polishing slurry used for subsequent removal of the anti-reflection coating layer is about 丨: jade: 2. Because the present invention uses mixing In the polishing slurry, components such as corrosion inhibitors and sonicating agents can interact with the copper metal layer 48b, and a protective layer is formed on the surface to protect the subsequent chemical mechanical polishing process. In a preferred embodiment of the present invention, The above-mentioned polishing slurry composition for removing the barrier material and the polishing slurry composition is composed of an organic polymer, inorganic polishing particles, a surfactant, and an acid-base buffer, and the polishing material for removing the barrier material and the anti-reflection coating are removed. The mixing ratio of the grinding slurry of the material can be between 〇 丨: 丨 〇 and i 〇: 0 · 1, and the preferred ratio is 1: 1. This paper size applies to Chinese National Standard (CNS) A4 Specifications (210X297mm) ............... Fees ........., 玎 ——, —— § (Please read the notes on the back before filling this page) Intellectual Property Bureau, Ministry of Economic Affairs Printed by the employee consumer cooperative 589678 A7 ---------------- B7 ___ V. Description of the invention () "Refer to Figure 6 and finally use the above to mix to remove anti-reflective coating The polishing slurry of the cloth layer 44 removes the anti-reflection coating layer 44a remaining on the surface of the dielectric layer 42 to form a structure as shown in FIG. 7. The present invention is characterized by removing the barrier layer and the anti-reflection coating layer. The mixing of the grinding slurry removes part of the deposited layer in the opening first, and then removes the remaining deposited layer on the surface of the dielectric layer, thereby reducing the consumption of copper metal materials in the opening. In addition, 'Although the polishing slurry for removing the barrier layer or the polishing slurry for removing the anti-reflective coating layer is generally used, a protective layer will also be formed on the surface of the steel metal', but the present invention uses a mixed polishing slurry which is used in combination with copper metal. The protective effect of the protective layer formed after the material acts is better than that of the general one, and the effect is better when the copper metal material of the thin wire portion is prevented from abrasion. It is worth noting that in the above-mentioned preferred embodiment of the present invention, the barrier layer is firstly subjected to a mechanical grinding step by using the slurry for removing the barrier layer to achieve the purpose of removing part of the barrier layer, but this is only an example. It is also possible to use a mixed slurry obtained by mixing the slurry for removing the barrier layer and the slurry for subsequent removal of the anti-reflection coating layer to directly perform chemical mechanical polishing on the barrier layer to remove the anti-reflection coating layer. The barrier layer 'on and above the trench' does not affect the efficacy of the invention, and the invention is not limited thereto. Due to the above-mentioned advantages, the use of the manufacturing method of the present invention can particularly prevent the copper metal dishing phenomenon in the thin wire portion. In addition to increasing the planarity of the surface of the integrated circuit and reducing the pattern sensitivity, electrical stability can also be increased to improve the life of the integrated circuit. This paper size applies to China National Standard (CNS) A4 (210X297 mm) ..., 耵 ......... B (Please read the back first Please pay attention to this page before filling out this page) 589678 A7 ΒΊ_ 5. Description of the invention () As understood by those skilled in the art, the above description is only a preferred embodiment of the present invention, and is not intended to limit the patent application of the present invention Scope; all other equivalent changes or modifications made without departing from the spirit disclosed by the present invention shall be included in the scope of patent application described below. (Please read the precautions on the back before filling out this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs This paper applies the Chinese National Standard (CNS) A4 specification (210X297 mm)

Claims (1)

589678 A8 B8 C8 D8 VI. Scope of patent application (please read the precautions on the back before filling this page) 1 · A chemical mechanical polishing process to prevent the thin wire dishing phenomenon in the copper process, including at least = performing a first chemical machinery The grinding step uses a first grinding polymer to remove a copper metal material. A second chemical mechanical grinding step uses a second grinding slurry to remove a first portion of a barrier layer. A third chemical machine is used. The grinding step is to mix the second grinding slurry and a third grinding slurry to remove a portion of an anti-reflection coating layer and a second portion of the barrier layer, wherein the portion of the anti-reflection coating layer and the barrier layer The second portion of the barrier layer is in contact with the edge of a trench; and a fourth chemical mechanical polishing step is performed to remove the anti-reflective coating layer remaining on the surface of a dielectric layer by using the third abrasive polymer. 2. For example, the chemical mechanical polishing process for preventing the thin wire and disk remaining phenomenon in the copper manufacturing process in the first patent application scope, wherein the first chemical mechanical polishing step includes at least: using a fourth polishing slurry to remove the copper metal material. One part makes the other part of the copper metal material have a thickness less than 2000A; the consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs prints and uses the first slurry to remove the other part of the copper metal material. 3. For the purpose of preventing the thin wires and discs from remaining in the copper process in the scope of the patent application, the paper size is applicable to the Chinese National Standard (CNS) A4 (210X 297 mm) 589678 printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs D8. The scope of patent application, chemical mechanical polishing process, where the material of the above barrier layer is selected from the group consisting of nitride button, titanium nitride, and titanium nitride button, and: anti-reflection coating layer Made of oxide. ^ 4. If the chemical mechanical polishing process to prevent the thin wire dishing phenomenon in the copper process of the scope of application for patent No. 丨, the copper metal material, the barrier layer and the anti-reflection coating layer in the first polishing slurry mentioned above The chemical mechanical polishing process for removing the thin wire and disc residue phenomenon in the steel process of item i of the patent application scope is removed in the aspect ratio of 40: 1: 1. The copper metal material of the second grinding slurry, The removal rate ratio of the barrier layer and the anti-reflection coating layer is 1: 2: 1. $ 大 6 · If the chemical mechanical polishing process to prevent the thin wire disk phenomenon in the copper process of the first scope of the patent application, the copper metal material, barrier layer and anti-reflection coating layer etched by the third polishing slurry mentioned above The removal rate ratio is 1: 2. Ma 1: 7. If the chemical mechanical polishing process to prevent the phenomenon of thin wire 磲 in the copper process of the scope of application for the patent, it further includes forming a protective layer in the trench after the third mechanical polishing = etching. Inside a copper metal (Please read the notes on the back before filling this page} . To prevent the thin wire dish in the copper process of Jiawei profit-seeking area 帛 i: three processes: chemical mechanical polishing process, where the mixing ratio of the second grinding slurry and one of the slurry is between 0 ": 10 to 10: 〇 ". 9 process, the chemical mechanical polishing to prevent the thin wire dishing phenomenon in the copper process at least includes a first chemical mechanical polishing step, which uses a first polishing slurry ^ one of the steel metal 钢 first part *, so that the surface The thickness of the remaining part of the metal hafnium is less than 2000A; a second chemical mechanical grinding step is performed, which uses a second grinding to remove a second part of the steel metal layer to expose a barrier layer; a third chemical mechanical The grinding step is to remove a first part of the barrier layer by using a third grinding slurry 2 to expose an anti-reflection coating. A fourth chemical mechanical grinding step is performed to mix the third grinding polymer with a fourth Grinding a slurry to remove a portion of the anti-reflection coating layer and the barrier layer—a second portion to expose a dielectric layer, wherein the portion of the anti-reflection coating layer and the second portion of the barrier layer The part is in contact with the edge of a groove ........., may -... (Please read the precautions on the back before filling this page ) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs; and A fifth step of chemical mechanical polishing 'by using the fourth polishing system to remove residual batt W antireflective coating layer to the surface of the dielectric layer. 12 This paper size applies Chinese National Standard (CNS) A4 specification (7mm of 210X) 589678 VI. Patent application scope ABCD 1 0 · Chemicals to prevent thin wires and discs in the copper process in item 9 of the patent scope of Shenyan In the mechanical polishing process, the material of the above barrier layer is selected from the group consisting of a nitride button, titanium nitride, and titanium tantalum nitride, and the anti-reflection coating layer is made of an oxide. 1 1 · If the chemical mechanical polishing process to prevent the thin wire dishing phenomenon in the copper manufacturing process in the 9th scope of the patent application, the copper metal material, barrier layer and anti-reflective coating layer in the second polishing slurry mentioned in # The removal rate ratio is 40: 1: 1.12. For example, the chemical mechanical polishing process for preventing the thin wire dishing phenomenon in the copper process of the patent application scope 帛 9, the copper metal material in the third grinding slurry mentioned above The removal rate of the barrier layer and the anti-reflection coating layer is larger ........... 磬 ......... (Please read the precautions on the back before filling this page) Economy Printed by the Intellectual Property Bureau of the Ministry of Intellectual Property and Consumer Cooperatives. For example, in the copper process of applying for item 9 of the patent scope, prevent thin wire disks. The removal rate ratio of the barrier layer and the anti-reflection coating layer is 1:14. As in the chemical mechanical polishing process for preventing fine conduction phenomenon in the copper process of item 9 of the patent application scope, among the above-mentioned four-pulp slurry-mixing The ratio is between. .... To the first = between pulp and the first king 10.0 · 1. 13 #Paper Size Gu Shoujia Standard (CNS) A4 Specification (21GX 297 Gongchu) — '--- i 589678 A8 B8 C8 Printed by the Consumers' Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs to apply for patents. 5. A chemical mechanical polishing process, which is used in a integrated circuit component manufacturing process for selective polishing. The chemical mechanical polishing process includes at least: A substrate of the first deposition layer, wherein the first deposition layer is located on at least a second deposition layer, and the second deposition layer is composed of at least one material; at least two grinding slurries are combined to form a mixed grinding Slurry, wherein the mixed grinding mill comprises at least a first grinding slurry for removing one of the first deposited layers and a second grinding slurry for removing one of the second deposited layers; and performing a chemical mechanical grinding step using the The grinding slurry is mixed to remove the first deposited layer and a portion of the second deposited layer. 16. The chemical mechanical polishing process of item 15 of the patent application scope, wherein the chemical mechanical polishing step further includes removing a first portion of the first deposited layer by using the first polishing slurry, and then using the mixed polishing And removing a second portion of the first deposited layer. 17 · If the chemical mechanical polishing process of item 15 of the patent application scope, wherein the chemical mechanical polishing step further includes using the mixed polishing slurry to remove the first deposited layer and a portion of the second deposited layer, The second abrasive slurry is used to remove another part of the second deposited layer. _This paper size applies to China National Standard (CNS) A4 specification (210X297 mm) .......... 41 ^ ......., Yiding ......... Φ (Please read the precautions on the back before filling in this page) 589678 ABCD VI. Application for Patent Scope 18 · If you apply for the chemical mechanical polishing process for Item 15 of the patent scope, where the first deposited layer is a barrier layer, the first The second deposition layer is an anti-reflection coating, and the material of the barrier layer is selected from the group consisting of a nitride button, titanium nitride, and a titanium nitride button. The anti-reflection coating layer is formed by oxidation. Composition of things. 19. If the chemical mechanical polishing process of item 15 of the scope of patent application, wherein the mixing ratio of the above-mentioned first slurry and one of the second slurry is between 0.1: 10 to 10: 0.1. 20 · If the chemical mechanical polishing process of item 15 of the scope of the patent application, the above-mentioned first-removing slurry is a steel metal material, the first deposition layer and the second deposition layer removal rate ratio is greater than 1: 21 · If you apply for the chemical mechanical polishing process of item _15, the second grinding slurry in the basin is a steel metal material and sinks ... The removal rate ratio of the second deposited layer is 1: 1: 2. ........... (Please read the precautions on the back before filling out this page) 1,2 tx% Printed on more than 15 paper sizes printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economy Applicable to Chinese National Standards (CNS) A4 size (210X 297 mm)