A polishing liquid for planarizing high-K dielectric metal gates and ruthenium gates of chips, and its preparation method and application

Abstract

The present invention relates to the technical field of chemical mechanical polishing. The present invention discloses a polishing liquid for planarizing a high-K dielectric metal gate of a chip, a ruthenium gate, and a preparation method and application thereof. The polishing liquid comprises the following components in concentration: 0.05-0.2 wt% of aluminum oxide abrasive particles; 0.05-0.2 wt% of an oxidant; 20-80 mmol / L of a complexing agent; and deionized water. The complexing agent is a DTPA(NH4)5 composite complexing agent. The polishing liquid prepared by the present invention can effectively improve the removal rate of the ruthenium gate during the chemical mechanical polishing process, while ensuring that the surface of the polished ruthenium gate has a nanometer-level surface roughness and defect-free characteristics, thereby solving the problem of low polishing rate caused by the high hardness and high chemical inertness of ruthenium and achieving high-quality surface processing of the ruthenium gate.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical mechanical polishing, and in particular to a polishing liquid for planarizing a high-K dielectric metal gate or a ruthenium gate of a chip, and a preparation method and application thereof. Background Art

[0002] Chemical mechanical polishing (CMP), a key technology in semiconductor processing, is used throughout all stages of wafer manufacturing, encompassing nearly every critical layer. The fundamental principle of CMP is that the wafer surface material reacts with the chemicals in the polishing slurry to form a softened layer, which is then removed under the contact pressure between the wafer and the polishing pad. During this process, the chemical reaction and mechanical wear of the abrasive particles occur instantaneously and alternately, synergistically removing the wafer surface material and achieving subnanometer-level polished surface quality.

[0003] High-k dielectric metal gate (HKMG) is the mainstream advanced structure used in 3D field-effect transistors in sub-10nm technology nodes. In the HKMG process, high-k dielectrics are used to improve gate leakage, while new metal gates are used to solve Fermi level pinning and polysilicon gate depletion problems. One of the important technical requirements is to achieve precise control of gate height, which usually requires that the gate height non-uniformity within and between wafers is less than 0. Chemical mechanical polishing of the metal gate is the last step in HKMG manufacturing. It can achieve global and local flattening of the wafer surface, determine the final height of the gate level, and is a key manufacturing process in the HKMG manufacturing process.

[0004] Ruthenium has the advantages of low resistivity (7.1μΩ·cm), high chemical inertness and good thermal stability. It is currently used as a new barrier layer material for sub-10nm nodes. In the HKMG structure, using metallic Ru instead of traditional Al or W as the gate material can significantly reduce chip power consumption and improve response speed. Current research on chemical mechanical polishing of Ru mainly focuses on Cu / Ru interconnect structures when Ru is used as a barrier layer. If Ru is used as the filler metal layer material of HKMG, the polishing process is more complicated and the control requirements for surface / interface defects are more stringent.

[0005] At present, there is almost no research on the chemical mechanical polishing process of Ru as the filling metal layer of HKMG at home and abroad. Therefore, there is an urgent need to develop an effective polishing solution suitable for the ruthenium gate of high-K dielectric metal gate (HKMG) of semiconductor chips to fill this gap. Summary of the Invention

[0006] The present invention aims to provide a polishing liquid for planarizing ruthenium high-K dielectric metal gates on chips, as well as a preparation method and application thereof. This polishing liquid for planarizing ruthenium high-K dielectric metal gates on chips can achieve high-speed ruthenium removal during the chemical mechanical polishing process of the ruthenium gate, while ensuring that the polished ruthenium gate surface has nanometer-scale surface roughness and is defect-free, thereby achieving high-quality surface processing of the ruthenium gate.

[0007] The scheme of the present invention is:

[0008] A polishing liquid for planarizing a ruthenium gate of a chip high-K dielectric metal gate (HKMG) comprises the following concentration components:

[0009] Alumina abrasive 0.05-0.2wt%;

[0010] Oxidant 0.05-0.2 wt%;

[0011] Complexing agent 20~80mmol / L;

[0012] Deionized water;

[0013] The complexing agent is a DTPA (NH4) 5 composite complexing agent, and the structural formula of the DTPA (NH4) 5 composite complexing agent is shown in the following formula I

[0014]

[0015] As a preferred technical solution, it also includes a pH regulator, which is selected from one or more of nitric acid and potassium hydroxide.

[0016] As a preferred technical solution, the oxidant is hydrogen peroxide.

[0017] As a preferred technical solution, the concentration of aluminum oxide abrasive particles is one of 0.05wt%, 0.1wt%, 0.15wt% and 0.2wt%.

[0018] As a preferred technical solution, the concentration of the oxidant is one of 0.05%, 0.1%, 0.15% and 0.2%.

[0019] As a preferred technical solution, the concentration of the DTPA(NH4)5 composite complexing agent is one of 20mmol / L, 40mmol / L, 60mmol / L and 80mmol / L.

[0020] The present invention also discloses a method for preparing a polishing liquid for planarizing a high-K dielectric metal gate or ruthenium gate of a chip, comprising the following steps:

[0021] 1) adding diethylenetriaminepentaacetic acid (DTPA) and ammonia water in sequence to deionized water, mixing, stirring, and simultaneously adding a saturated pH adjuster to the solution until the diethylenetriaminepentaacetic acid (DTPA) is completely dissolved and the pH value of the solution is alkaline, thereby obtaining a complexing agent;

[0022] 2) adding 0.05-0.2 wt% of an oxidant to deionized water, and then adding 20-80 mmol / L of the complexing agent prepared in step 1), adjusting the pH, and obtaining a polishing solution;

[0023] 3) During polishing, 0.05-0.2 wt % of aluminum oxide abrasive particles are added to the polishing liquid to obtain a polishing liquid for planarizing a high-K dielectric metal gate or a ruthenium gate of a chip.

[0024] As a preferred technical solution, the pH value of the polishing liquid in 2) is 8-11.

[0025] The invention also discloses the application of a polishing liquid for planarizing a high-K dielectric metal gate and a ruthenium gate of a chip in chemical mechanical polishing.

[0026] As a preferred technical solution, the physical parameters of the polishing liquid used for flattening the high-K dielectric metal gate ruthenium gate of the chip during polishing are pressure: 2psi; polishing head speed: 101rpm; polishing disk speed: 99rpm; polishing liquid flow rate: 100mL / min; polishing time: 5min.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) High-efficiency ruthenium removal performance: The polishing liquid provided by the present invention can achieve high-speed removal of ruthenium during the chemical mechanical polishing (CMP) process, significantly improving process efficiency.

[0029] (2) Surface quality optimization: The surface of the ruthenium gate polished with the polishing liquid provided by the present invention has a nanometer-level surface roughness and can ensure that it is defect-free, which significantly improves the surface quality of the metal gate and meets the high-standard process requirements of semiconductor chips.

[0030] (3) Precise process control: The present invention can achieve precise control of gate height by optimizing the polishing liquid composition and process parameters (such as pH, pressure, rotation speed, etc.), meeting the requirements of less than 10nm technology node wafer height non-uniformity within and between wafers. requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1The XPS 3d spectra of the ruthenium surfaces after immersion in the polishing liquids of Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4 of the present invention are shown; wherein a is Comparative Example 1; b is Comparative Example 2; c is Comparative Example 3; d is Comparative Example 4; and e is Example 1;

[0032] Figure 2 The open circuit potential and electrochemical impedance spectroscopy diagram of ruthenium in different types of complexing agents of the present invention are shown in FIG. 1 , wherein a is the open circuit potential; b is the Nyquist diagram and equivalent circuit diagram of the electrochemical impedance spectroscopy (EIS); c is the Bode modulus diagram; and d is the Bode phase angle diagram.

[0033] Figure 3 The open circuit potential and electrochemical impedance spectroscopy of Ru in DTPA (NH4) 5 solutions of different concentrations of the present invention are shown; wherein a is the open circuit potential; b is the Nyquist diagram; c is the Bode modulus diagram; d is the Bode phase angle diagram;

[0034] Figure 4 These are the two-dimensional and three-dimensional morphology images of Ru before and after polishing of the present invention: the left side is the two-dimensional morphology image, the right side is the three-dimensional morphology image, a and b are before polishing; c and d are after polishing. DETAILED DESCRIPTION

[0035] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0036] In the following examples and comparative examples, the Ru polishing removal rate was measured using the following method: Polishing experiments were conducted on a self-developed ultra-low downforce polisher. After polishing, the sample was rinsed with deionized water to remove most of the colloidal alumina particles and other impurities adsorbed on the ruthenium surface due to its electronegativity, and then dried with nitrogen. The Ru-MRR was calculated by the difference in sample weight before and after the polishing experiment using the following formula:

[0037]

[0038] Where: MRR is the polishing rate; Δm is the mass difference before and after polishing; ρ is the density of ruthenium; r is the radius of the polishing metal disk; t is the polishing time.

[0039] In the following examples and comparative examples, electrochemical testing of ruthenium was performed using a Princeton VersaSTAT 3 electrochemical workstation and a standard three-electrode electrolytic cell to compare their galvanic corrosion trends. In these tests, a Pt electrode served as the counter electrode, a saturated calomel electrode (SCE) served as the reference electrode, and ruthenium (99.99% purity) served as the working electrode.

[0040] In the following examples and comparative examples, X-ray photoelectron spectroscopy (XPS) of ruthenium surfaces after static etching was performed using a PHIQuantera II X-ray photoelectron spectrometer to determine the product after immersion in various complexing agent solutions. Before testing, the ruthenium samples were soaked in 50 mM citric acid for 5 minutes to remove native surface oxides. They were then soaked in the complexing agent solution for 10 minutes, dried with nitrogen, and stored under vacuum.

[0041] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments.

[0042] Take 3.15g of diethylenetriaminepentaacetic acid (DTPA) and 2.74g of 25% ammonia water, add them to 44.11g of deionized water, mix, stir and slowly add saturated KOH to the solution until the diethylenetriaminepentaacetic acid (DTPA) is completely dissolved and the pH value of the titrated solution is between 8.5 and 9.5, thus obtaining the DTPA(NH4)5 complexing agent.

[0043] Example 1

[0044] Add 0.5 g of 30 wt% H2O2 to 87 g of deionized water, then add 12.5 g of DTPA(NH4)5 complexing agent. Saturated KOH or saturated HNO3 is added while stirring, and the pH of the solution is adjusted to 10. This results in a polishing solution with an H2O2 concentration of 0.15 wt% and a DTPA(NH4)5 complexing agent concentration of 20 mmol / L.

[0045] During polishing, the polishing slurry prepared in this example contained 0.2 wt% of the aluminum oxide abrasive relative to the total mass of the polishing slurry. The physical parameters of the polishing slurry during polishing were: pressure: 2 psi; polishing head speed: 101 rpm; polishing disk speed: 99 rpm; polishing slurry flow rate: 100 mL / min; and polishing time: 5 min. Under these conditions, the polishing rate of ruthenium was 41.08 nm / min. Three-dimensional white light testing was performed on the polished ruthenium surface to measure the surface roughness before and after polishing.

[0046] Using ruthenium as the research electrode, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) tests were performed. The specific test results are shown in Figure 3 , Table 3.

[0047] Example 2

[0048] Add 0.5 g of 30 wt% H2O2 to 74.5 g of deionized water, then add 25 g of DTPA(NH4)5 complexing agent. Saturated KOH or saturated HNO3 is added while stirring, and the pH of the solution is adjusted to 10. This results in a polishing solution with an H2O2 concentration of 0.15 wt% and a DTPA(NH4)5 complexing agent concentration of 40 mmol / L.

[0049] During polishing, the polishing slurry prepared in this example contained 0.2 wt% of the aluminum oxide abrasive relative to the total mass of the slurry. The physical parameters during polishing were: pressure: 2 psi; polishing head speed: 101 rpm; polishing disk speed: 99 rpm; polishing slurry flow rate: 100 mL / min; and polishing time: 5 min. Under these conditions, the polishing rate for ruthenium was 47.97 nm / min.

[0050] Using ruthenium as the research electrode, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) tests were performed. The specific test results are shown in Figure 3 , Table 3.

[0051] Example 3

[0052] Add 0.5 g of 30 wt% H2O2 to 62 g of deionized water, then add 37.5 g of DTPA(NH4)5 complexing agent. Saturated KOH or saturated HNO3 is added while stirring, and the pH of the solution is adjusted to 10. This results in a polishing solution with an H2O2 concentration of 0.15 wt% and a DTPA(NH4)5 complexing agent concentration of 60 mmol / L.

[0053] During polishing, the polishing slurry prepared in this example contained 0.2 wt% of the aluminum oxide abrasive relative to the total mass of the slurry. The physical parameters during polishing were: pressure: 2 psi; polishing head speed: 101 rpm; polishing disk speed: 99 rpm; polishing slurry flow rate: 100 mL / min; and polishing time: 5 min. Under these conditions, the polishing rate for ruthenium was 57.53 nm / min.

[0054] Using ruthenium as the research electrode, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) tests were performed. The specific test results are shown in Figure 3 , Table 3.

[0055] Example 4

[0056] Add 0.5 g of 30 wt% H2O2 to 49.5 g of deionized water, then add 50 g of DTPA(NH4)5 complexing agent. Saturated KOH or saturated HNO3 is added while stirring, and the pH of the solution is adjusted to 10. This results in a polishing solution with an H2O2 concentration of 0.15 wt% and a DTPA(NH4)5 complexing agent concentration of 80 mmol / L.

[0057] The polishing slurry prepared in this example contained 0.2 wt% of the aluminum oxide abrasive relative to the total mass of the slurry. The physical parameters during polishing were: pressure: 2 psi; polishing head speed: 101 rpm; polishing disk speed: 99 rpm; polishing slurry flow rate: 100 mL / min; and polishing time: 5 min. Under these conditions, the polishing rate for ruthenium was 57.50 nm / min.

[0058] Using ruthenium as the research electrode, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) tests were performed. The specific test results are shown in Figure 3 , Table 3.

[0059] Comparative Example 1

[0060] Take 0.5g of 30wt% H2O2 and add it to 99.5g of deionized water. No additional complexing agent is added. Saturated KOH or saturated HNO3 is added while stirring. The pH of the solution is adjusted to 10. A polishing solution with a H2O2 content of 0.15wt% is prepared. The ruthenium-coated film is immersed in the prepared polishing solution for 10 minutes and then subjected to X-ray photoelectron spectroscopy. The specific test results are shown in Figure 1 , Table 1.

[0061] The polishing slurry prepared in this comparative example contained 0.2 wt% of the abrasive, based on the total mass of the slurry. The physical parameters during polishing were: pressure: 2 psi; polishing head speed: 101 rpm; polishing disk speed: 99 rpm; polishing slurry flow rate: 100 mL / min; and polishing time: 5 min. Under these conditions, the polishing rate for ruthenium was 15.26 nm / min.

[0062] Using ruthenium as the research electrode, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) tests were performed. The specific test results are shown in Figure 2 , Table 2.

[0063] Comparative Example 2

[0064] Take 0.5g of 30wt% H2O2 and add it to 99.15g of deionized water. Add 0.35g of K2SO4 and add saturated KOH or saturated HNO3 while stirring. Adjust the pH of the solution to 10. Prepare a polishing solution with a H2O2 content of 0.15wt% and a K2SO4 content of 20mmol / L. Soak the ruthenium-coated film in the prepared polishing solution for 10 minutes and then perform X-ray photoelectron spectroscopy. The specific test results are shown in Figure 1 , Table 1.

[0065] The polishing slurry prepared in this comparative example contained 0.2 wt% of the abrasive, based on the total mass of the slurry. The physical parameters during polishing were: pressure: 2 psi; polishing head speed: 101 rpm; polishing disk speed: 99 rpm; polishing slurry flow rate: 100 mL / min; and polishing time: 5 min. Under these conditions, the polishing rate for ruthenium was 23.18 nm / min.

[0066] Using ruthenium as the research electrode, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) tests were performed. The specific test results are shown in Figure 2 , Table 2.

[0067] Comparative Example 3

[0068] Take 0.5g of 30wt% H2O2 and add it to 98.71g of deionized water. Add 0.79g of DTPA and add saturated KOH or saturated HNO3 while stirring. Adjust the pH of the solution to 10. Prepare a polishing solution with a H2O2 content of 0.15wt% and a DTPA content of 20mmol / L. Soak the ruthenium-coated film in the prepared polishing solution for 10 minutes and then perform X-ray photoelectron spectroscopy. The specific test results are shown in Figure 1 , Table 1.

[0069] The polishing slurry prepared in this comparative example contained 0.2 wt% of the abrasive, based on the total mass of the slurry. The physical parameters during polishing were: pressure: 2 psi; polishing head speed: 101 rpm; polishing disk speed: 99 rpm; polishing slurry flow rate: 100 mL / min; and polishing time: 5 min. Under these conditions, the polishing rate for ruthenium was 33.36 nm / min.

[0070] Using ruthenium as the research electrode, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) tests were performed. The specific test results are shown in Figure 2 , Table 2.

[0071] Comparative Example 4

[0072] Take 0.5g of 30wt% H2O2 and add it to 98.84g of deionized water. Add 0.66g of (NH4)2SO4 and add saturated KOH or saturated HNO3 while stirring. Adjust the pH of the solution to 10. Prepare a polishing solution with a H2O2 content of 0.15wt% and a (NH4)2SO4 content of 20mmol / L. Soak the ruthenium-coated film in the prepared polishing solution for 10 minutes and then perform X-ray photoelectron spectroscopy testing. The specific test results are shown in Figure 1 , Table 1.

[0073] The polishing slurry prepared in this comparative example contained 0.2 wt% of the abrasive, based on the total mass of the slurry. The physical parameters during polishing were: pressure: 2 psi; polishing head speed: 101 rpm; polishing disk speed: 99 rpm; polishing slurry flow rate: 100 mL / min; and polishing time: 5 min. Under these conditions, the polishing rate for ruthenium was 39.60 nm / min.

[0074] Using ruthenium as the research electrode, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) tests were performed. The specific test results are shown in Figure 2 , Table 2.

[0075] Comparative Example 5

[0076] Take 0.5g of 30wt% H2O2 and add it to 96.61g of deionized water, add 0.79g of DTPA and 0.66g of (NH4)2SO4, add saturated KOH or saturated HNO3 while stirring, and adjust the pH of the solution to 10. A polishing solution with a H2O2 content of 0.15wt% and a DTPA and (NH4)2SO4 content of 20mmol / L is prepared. The ruthenium-coated film is immersed in the prepared polishing solution for 10 minutes, and then subjected to X-ray photoelectron spectroscopy testing. The specific test results are shown in Figure 1 , Table 1.

[0077] The polishing slurry prepared in this comparative example contained 0.2 wt% of the abrasive, based on the total mass of the slurry. The physical parameters during polishing were: pressure: 2 psi; polishing head speed: 101 rpm; polishing disk speed: 99 rpm; polishing slurry flow rate: 100 mL / min; and polishing time: 5 min. Under these conditions, the polishing rate for ruthenium was 41.08 nm / min.

[0078] Using ruthenium as the research electrode, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) tests were performed. The specific test results are shown in Figure 2 , Table 2.

[0079] Table 1 The proportion of Ru surface components after immersion in different solutions

[0080]

[0081] Table 2 Electrochemical impedance spectroscopy fitting results of Ru in different types of complexing agents Complexing agent type Solution resistance (Ω·cm 2 )Admittance constant(10 -6 F·cm -2 )Polarization resistance (Ω·cm 2 )Fitting degree(10 -3 )

[0082]

[0083] Table 3 Electrochemical impedance spectroscopy fitting results of Ru in DTPA(NH4)5 solutions with different concentrations

[0084]

[0085] From Table 1 and Figure 1 Analysis shows that after adding different types of complexing agents, the metallic Ru content on the Ru surface increases, the RuO2 content decreases, and the RuO3 content increases. This indicates that the complexing agent can react with the ruthenium oxide on the surface, destroying the dense RuO2 passivation layer on the surface, thereby increasing the ruthenium removal rate during the polishing process. Compared with the comparative example, the composite complexing agent DTPA(NH4)5 added in Example 1 has the best complexing effect.

[0086] From Table 2 and Figure 2 Analysis shows that as K + ,DTPA x- , NH4 + , DTPA(NH4)5 were introduced respectively, the open circuit potential of Ru decreased and the polarization resistance decreased respectively, indicating that the complexing effect of the above ions on Ru was enhanced successively. When equal amounts of DTPAK5 and (NH4)2SO4 were added to the solution at the same time, the changes in electrochemical parameters were similar to those when DTPA(NH4)5 was added alone, indicating that the complexing ability of the composite complexing agent DTPA(NH4)5 comes from the ionization of DTPA(NH4)5 and the ionization of DTPA(NH4)5. x- Complexation of Ru and its oxides and NH4 generated by DTPA(NH4)5 ionization + Amination and complexation of Ru and its oxides.

[0087] From Table 3 and Figure 3 Analysis shows that as the concentration of the complexing agent DTPA(NH4)5 increases, the open-circuit potential of Ru decreases. The polarization resistance of the Ru surface gradually decreases, and the polishing rate gradually increases. This indicates that DTPA(NH4)5 can reduce the density of the Ru surface oxide film and exhibit a strong complexing effect during the Ru CMP process.

[0088] Depend on Figure 4 It can be seen that after polishing with the polishing liquid prepared in Example 1, the surface roughness Sa of Ru was reduced from 5.00 nm to 1.24 nm. The surface quality after polishing was significantly improved, which can meet the processing requirements of high-k dielectric metal gate (HKMG) ruthenium (Ru) gate.

[0089] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A polishing liquid for planarizing high-K dielectric metal gates and ruthenium gates on chips, characterized in that: Contains the following concentration components: Alumina abrasive 0.05~0.2wt%; Oxidant 0.05~0.2wt%; Complexing agent 20-80 mmol / L; Deionized water; The complexing agent is a DTPA (NH4) 5 composite complexing agent, and the structural formula of the DTPA (NH4) 5 composite complexing agent is as follows: ； Also includes a pH regulator, the pH regulator is selected from one of nitric acid and potassium hydroxide; The oxidant is hydrogen peroxide; The method for preparing a polishing liquid for planarizing a high-K dielectric metal gate and a ruthenium gate of a chip comprises the following steps: 1) Diethylenetriaminepentaacetic acid and ammonia water are sequentially added to deionized water, mixed, and stirred while adding a saturated pH adjuster to the solution until the diethylenetriaminepentaacetic acid is completely dissolved and the pH value of the solution is alkaline, thereby obtaining a complexing agent; 2) adding 0.05-0.2 wt% of an oxidant to deionized water, and then adding 20-80 mmol / L of the complexing agent prepared in step 1), adjusting the pH, to obtain a polishing solution; 3) During polishing, 0.05 to 0.2 wt % of aluminum oxide abrasive particles are added to the polishing liquid to obtain a polishing liquid for planarizing a high-K dielectric metal gate and a ruthenium gate of a chip.

2. The polishing liquid for planarizing a high-K dielectric metal gate or ruthenium gate of a chip according to claim 1, characterized in that: The concentration of the aluminum oxide abrasive grains is one of 0.05 wt %, 0.1 wt %, 0.15 wt % and 0.2 wt %.

3. The polishing liquid for planarizing a high-K dielectric metal gate or ruthenium gate of a chip according to claim 1, wherein: The concentration of the oxidant is one of 0.05wt%, 0.1wt%, 0.15wt% and 0.2wt%.

4. The polishing liquid for planarizing a high-K dielectric metal gate or ruthenium gate of a chip according to claim 1, wherein: The concentration of the DTPA(NH4)5 composite complexing agent is one of 20 mmol / L, 40 mmol / L, 60 mmol / L and 80 mmol / L.

5. The polishing liquid for planarizing a high-K dielectric metal gate or ruthenium gate of a chip according to claim 1, wherein: The pH value of the polishing liquid in the above 2) is 8-11.

6. Use of the polishing liquid for planarizing a high-K dielectric metal gate or ruthenium gate of a chip as claimed in any one of claims 1 to 5 in chemical mechanical polishing.

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