Leveling composition as well as preparation method and application thereof

Abstract

The invention provides a leveling composition and a preparation method and application thereof.The leveling composition comprises negatively charged nanoparticles, an oxidizing agent, a catalyst, a corrosion inhibitor, a titanium nitride regulator and a solvent, and the titanium nitride regulator comprises organic carboxylic acid; the primary dissociation constant pKa1 of the organic carboxylic acid is less than or equal to the sum of the pH value of the leveling composition plus 0.5, and the secondary dissociation constant pKa2 of the organic carboxylic acid is greater than or equal to the sum of the pH value of the leveling composition and 0.5. Under the synergistic effect of all the components, the titanium nitride conditioning agent meeting the specific relation is selected, the leveling speed of titanium nitride is reduced while the leveling effect of a leveling workpiece is not affected, independent regulation and control of titanium nitride are achieved, the leveling speed selection ratio of titanium nitride and silicon nitride is reduced, and the leveling effect of titanium nitride and silicon nitride is improved. When the method is applied to preparation of semiconductor devices, the comprehensive performance of the semiconductor devices can be improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor preparation, and in particular to a planarization composition, a preparation method thereof, and an application thereof. Background Art

[0002] With the continuous development of semiconductor technology, the industry has higher requirements for the high density and miniaturization of semiconductor devices, resulting in more and more complex multi-layer wiring structures of substrates in semiconductor preparation processes, so that the substrate surface has a certain height difference. At present, it is necessary to perform a flattening treatment on the substrate by a flattening composition to improve the flatness of the substrate surface. Since the substrate surface is a composite surface, including metals, oxides and nitrides, etc., the interface properties are complex. When the existing flattening composition flattens the composite substrate, the titanium nitride and silicon nitride with similar properties have a synchronous flattening speed, and it is impossible to achieve the flattening speed regulation of titanium nitride alone. Therefore, the present application provides a flattening composition that has a separate regulating effect on titanium nitride and can reduce the flattening speed of titanium nitride, reduce the flattening speed selection ratio of titanium nitride and silicon nitride, so as to improve the flattening effect and enhance the overall performance of semiconductor devices. Summary of the Invention

[0003] In view of this, the present application provides a planarizing composition, a preparation method, and an application thereof. The planarizing composition is used for planarizing a workpiece containing titanium nitride. Through the synergistic effect of the various components, the electrostatic repulsion between the titanium nitride surface and the negatively charged nanoparticles in the workpiece is enhanced. Without affecting the overall planarization effect of the workpiece, the planarization speed of the titanium nitride is reduced, and the titanium nitride planarization speed is independently regulated, thereby reducing the planarization speed selectivity ratio of titanium nitride and silicon nitride, which is beneficial to improving the overall performance of semiconductor devices.

[0004] In the first aspect, the present application provides a planarization composition for planarizing a workpiece containing titanium nitride, the planarization composition comprising negatively charged nanoparticles, an oxidant, a catalyst, a corrosion inhibitor, a titanium nitride regulator, and a solvent, the titanium nitride regulator comprising an organic carboxylic acid, the first dissociation constant pKa1 of the organic carboxylic acid being less than or equal to the sum of the pH value of the planarization composition and 0.5, and the second dissociation constant pKa2 of the organic carboxylic acid being greater than or equal to the sum of the pH value of the planarization composition and 0.5. In the present application, by combining the various components and selecting a titanium nitride regulator that meets specific requirements, the titanium nitride surface can be made to have a strong negative charge, while the silicon nitride surface is uncharged. Under the action of the negatively charged nanoparticles, the planarization speed of titanium nitride can be separately regulated, thereby reducing the planarization speed selectivity ratio of titanium nitride and silicon nitride, thereby improving the stability of the preparation process of semiconductor devices and enhancing the overall performance of semiconductor devices.

[0005] Optionally, the organic carboxylic acid includes two or more carboxyl groups, and the organic carboxylic acid includes one or more of tartaric acid, citric acid, malonic acid, glutaric acid, succinic acid, and azelaic acid. The polycarboxylic acid organic compound can reduce the planarization rate of titanium nitride while maintaining a high planarization rate of silicon nitride, thereby reducing the planarization rate selectivity of titanium nitride to silicon nitride.

[0006] Optionally, the pH of the planarization composition is 2 to 5. A suitable pH can enhance the electrostatic repulsion between the titanium nitride surface and the negatively charged nanoparticles, reduce the planarization speed of the titanium nitride surface, and further reduce the planarization speed selectivity of titanium nitride and silicon nitride.

[0007] Optionally, the negatively charged nanoparticles have a zeta potential of less than or equal to -20 mV, and the negatively charged nanoparticles include one or more of natural abrasives and abrasives containing modified groups. Negatively charged nanoparticles have excellent planarization effects. When used on workpieces containing metallic tungsten, titanium nitride, and silicon nitride, the planarization speed of metallic tungsten and silicon nitride is high. Meanwhile, electrostatic repulsion reduces the planarization speed of only the titanium nitride surface, thereby reducing the planarization speed selectivity of titanium nitride and silicon nitride.

[0008] Optionally, the oxidant includes one or more of hydrogen peroxide, performic acid, peracetic acid, and peroxypropionic acid. The oxidant can oxidize the surface of the metal tungsten to form a softened tungsten oxide layer, thereby promoting the removal of the metal tungsten and increasing the metal tungsten removal rate.

[0009] Optionally, the catalyst includes an iron-containing compound. The catalyst can promote the oxidation of the oxidant on the metal tungsten, increase the flattening speed of the metal tungsten, and enhance the flattening effect of the workpiece to be flattened.

[0010] Optionally, the corrosion inhibitor includes amino acids, including one or more of lysine, histidine, serine, and tyrosine. The corrosion inhibitor can reduce excessive corrosion of the tungsten metal by other components in the planarization composition, avoid the generation of surface defects, and improve the planarization effect.

[0011] Optionally, in the planarization composition, the mass percentage of the negatively charged nanoparticles is 0.01%-1%; and / or the mass percentage of the oxidant is 0.1%-3%; and / or the mass percentage of the catalyst is 0.01%-1%; and / or the mass percentage of the corrosion inhibitor is 0.01%-1%; and / or the mass percentage of the titanium nitride modifier is 0.1%-1%. Appropriate amounts of each component in the planarization composition can increase the planarization speed of tungsten metal, avoid excessive corrosion of tungsten metal, reduce surface defects, and reduce the planarization speed of titanium nitride, thereby lowering the selectivity of the planarization speeds of titanium nitride and silicon nitride.

[0012] Optionally, the planarization composition further includes a silicon nitride regulator, which includes polyvinyl pyrrolidone and its derivatives, to further control the planarization speed of silicon nitride, thereby adjusting the planarization speed selection ratio of titanium nitride and silicon nitride.

[0013] Optionally, in the planarization composition, the mass percentage of the silicon nitride regulator is 0.001%-0.1%.

[0014] In a second aspect, the present application provides a planarization process, comprising:

[0015] The flattening composition is used to flatten a workpiece to be flattened to obtain a flattened workpiece. The flattening process provided by the present application has high stability, good flattening effect, low flattening speed selectivity of titanium nitride and silicon nitride, and the obtained flattened workpiece has excellent comprehensive performance.

[0016] Optionally, the surface of the workpiece to be planarized comprises titanium nitride and silicon nitride, and the planarization rate selectivity ratio of the titanium nitride to the silicon nitride is less than or equal to 10. The smaller the selectivity ratio, the higher the selectivity of the planarization composition for titanium nitride, which can further reduce the planarization rate of titanium nitride, thereby improving the independent regulation of titanium nitride. DETAILED DESCRIPTION

[0017] The following is a clear and complete description of the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0018] With the development of semiconductor technology, the integration of semiconductor integrated circuits has increased, and the requirements for high density and miniaturization of semiconductor devices have become increasingly higher. This has increased the complexity of the multi-layer wiring structure of the substrate in the semiconductor manufacturing process. In the semiconductor manufacturing process, the multi-layer wiring structure of the substrate is formed through multiple film formation and etching, which easily produces nanometer-level height differences on the substrate surface, which is not conducive to the subsequent process. At present, it is necessary to use a planarization composition for planarization treatment to eliminate the height difference on the substrate surface and improve the flatness of the substrate. Because the substrate surface is a composite surface, the interface properties are complex, including metals, oxides and nitrides. When the existing planarization composition is used to planarize the substrate containing metal tungsten, the metal tungsten, oxides, silicon nitride, titanium nitride, etc. on the surface are removed at the same flattening speed. It is difficult to separately regulate silicon nitride and titanium nitride, which have similar properties. It is impossible to increase or decrease the flattening speed of titanium nitride alone. It does not have the ability to separately regulate titanium nitride, which is not conducive to the semiconductor process and has limited improvement in the overall performance of semiconductor devices.

[0019] In order to solve the above technical problems, the present application provides a planarization composition, including negatively charged nanoparticles, an oxidant, a catalyst, a corrosion inhibitor, a titanium nitride regulator and a solvent, wherein the titanium nitride regulator includes an organic carboxylic acid, wherein the first dissociation constant pKa1 of the organic carboxylic acid is less than or equal to the sum of the pH value of the planarization composition and 0.5, and the second dissociation constant pKa2 of the organic carboxylic acid is greater than or equal to the sum of the pH value of the planarization composition and 0.5. In the present application, the planarization composition is used for planarization treatment of workpieces containing titanium nitride, and the titanium nitride regulator can be attached to the titanium nitride surface in the planarized workpiece through coordination, and according to the pH value of the planarization composition, an organic carboxylic acid with a first dissociation constant less than or equal to the sum of the pH value of the planarization composition and 0.5 and a second dissociation constant pKa2 greater than or equal to the sum of the pH value of the planarization composition and 0.5 is selected as the titanium nitride regulator, so that the organic carboxylic acid undergoes first dissociation, and the dissociated organic carboxylic acid has a strong negative charge, thereby making it attached. The titanium nitride surface has a strong negative charge, generating a strong electrostatic repulsion force with negatively charged nanoparticles, which can reduce the titanium nitride flattening speed. Under the synergistic effect of the various components, the flattening composition can grind and remove workpieces containing titanium nitride and silicon nitride. Because silicon nitride only binds to organic carboxylic acids through dissociated carboxyl groups, the organic carboxylic acid surface attached to the silicon nitride surface no longer has dissociated carboxylic acid groups. Therefore, the silicon nitride surface is uncharged and cannot repel negatively charged nanoparticles, making it impossible to regulate the silicon nitride flattening speed. Therefore, selecting a titanium nitride regulator that meets specific requirements can achieve separate regulation of the titanium nitride flattening speed, thereby reducing the flattening speed selectivity of titanium nitride and silicon nitride, improving the stability of the semiconductor device manufacturing process, and enhancing the overall performance of semiconductor devices.

[0020] In the present application, the titanium nitride regulator includes an organic carboxylic acid, the first dissociation constant pKa1 of the organic carboxylic acid is less than or equal to the sum of the pH value of the planarizing composition and 0.5, and the second dissociation constant pKa2 of the organic carboxylic acid is greater than or equal to the sum of the pH value of the planarizing composition and 0.5. Under this pH value condition, the titanium nitride regulator that meets this specific requirement undergoes first dissociation of the organic carboxylic acid, and the undissociated carboxyl groups are attached to the titanium nitride surface through coordination. At the same time, the dissociated carboxyl groups are attached to the titanium nitride surface, making the titanium nitride surface negatively charged, thereby enhancing the electrostatic repulsion force between the titanium nitride surface and the negatively charged nanoparticles, and reducing the planarization speed of titanium nitride. For example, when the pH value of the planarization composition is A, the first-order dissociation constant pKa1 of the organic carboxylic acid is less than or equal to A+0.5, and the second-order dissociation constant pKa2 of the organic carboxylic acid is greater than or equal to A+0.5. At this time, the organic carboxylic acid can undergo complete first-order dissociation, and one of the carboxyl groups in the organic carboxylic acid dissociates to form a carboxylate radical with a strong negative charge, thereby making the titanium nitride surface with the organic carboxylic acid attached have a strong negative charge, generating a strong electrostatic repulsive force with the negatively charged nanoparticles, thereby realizing the separate regulation of the titanium nitride planarization speed, thereby reducing the titanium nitride and titanium nitride planarization speed selectivity ratio.

[0021] In one embodiment of the present application, the organic carboxylic acid may include, but is not limited to, one or more carboxyl groups, such as tartaric acid, citric acid, malonic acid, glutaric acid, succinic acid, and azelaic acid. While maintaining a relatively high silicon nitride flattening speed, the polycarboxylic acid organic compound can reduce the flattening speed of titanium nitride, thereby reducing the flattening speed selectivity of titanium nitride and silicon nitride. Specifically, in the polycarboxylic acid organic compound, part of the carboxyl groups are bound to the titanium nitride surface through coordination, and the other part of the dissociated carboxyl groups is free on the titanium nitride surface, enhancing the electrostatic repulsion force between titanium nitride and nanoparticles, thereby reducing the flattening speed of titanium nitride; at the same time, the silicon nitride surface is connected to the organic carboxylic acid structure after dissociation, and the organic carboxylic acid surface attached to the silicon nitride surface no longer has a dissociated group, so the silicon nitride surface is uncharged and cannot repel the negatively charged nanoparticles, thereby achieving a separate regulation of the flattening speed of titanium nitride, thereby reducing the flattening speed selectivity of titanium nitride and silicon nitride. In one embodiment of the present application, the titanium nitride modifier can be citric acid. Citric acid has three carboxyl groups, and the higher the degree of dissociation, the stronger the negative charge on the titanium nitride surface, which can further increase the planarization speed of the titanium nitride surface. In another embodiment of the present application, the titanium nitride modifier can be succinic acid.

[0022] In one embodiment of the present application, the pH value of the planarization composition is 2-5. The appropriate pH value can enhance the electrostatic repulsion force between the titanium nitride surface and the negatively charged nanoparticles, reduce the planarization speed of the titanium nitride surface, and further reduce the planarization speed selectivity of titanium nitride and silicon nitride. Specifically, the pH value of the planarization composition can be, but is not limited to, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, 4, 4.2, 4.5, 4.8 or 5. In one embodiment of the present application, the pH value of the planarization composition can be 2-4.2. In another embodiment of the present application, the pH value of the planarization composition can be 3-5. In some embodiments, when the pH value of the planarization composition is 3, the organic carboxylic acid may include one or more of citric acid (pKa1: 3.13, pKa2: 4.76), tartaric acid (pKa1: 2.98, pKa2: 4.34), and malonic acid (pKa1: 2.85, pKa2: 5.66). In other embodiments, when the pH value of the planarization composition is 4, the organic carboxylic acid may include citric acid (pKa1: 3.13, pKa2: 4.76), malonic acid (pKa1: 2.85, pKa2: 5.66), glutaric acid (pKa1: 3.77, pKa2: 6.08), and succinic acid (pKa1: 4.16, pKa2: 5.64).

[0023] In one embodiment of the present application, in the leveling composition, the mass percentage of the titanium nitride regulator is 0.1%-1%. An appropriate amount of titanium nitride regulator can reduce the leveling speed of titanium nitride, but does not affect the leveling speed of the leveling composition on metal tungsten, oxides and silicon nitride, thereby achieving separate regulation of titanium nitride. Specifically, in the leveling composition, the mass percentage of the titanium nitride regulator can be, but is not limited to, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1%, etc. In one embodiment of the present application, in the leveling composition, the mass percentage of the titanium nitride regulator can be 0.1%-0.6%. In another embodiment of the present application, in the leveling composition, the mass percentage of the titanium nitride regulator can be 0.5%-1%. In the present application, the titanium nitride regulator and its content in the planarization composition can be characterized by, but not limited to, LC-MS (liquid chromatography-mass spectrometry), GC-MS (gas chromatography-mass spectrometry), infrared testing, nuclear magnetic resonance testing, and the like.

[0024] In the present application, negatively charged nanoparticles can achieve excellent flattening effects on workpieces to be flattened. When used on workpieces containing tungsten metal, titanium nitride, and silicon nitride, the flattening speed of tungsten metal and silicon nitride is high. At the same time, through electrostatic repulsion, the flattening speed of titanium nitride surfaces is reduced, reducing the flattening speed selectivity of titanium nitride and silicon nitride. In one embodiment of the present application, the negatively charged nanoparticles may include, but are not limited to, one or more of natural abrasives and abrasives containing modified groups. For example, natural abrasives may include, but are not limited to, aluminum oxide, silicon oxide, zirconium oxide, etc.; abrasives containing modified groups may include silicon oxide, aluminum oxide, zirconium oxide, etc. coated with sulfate groups, or silicon oxide, aluminum oxide, zirconium oxide, etc. coated with sulfonate groups. In one embodiment of the present application, the negatively charged nanoparticles may be negatively charged silica sol. In another embodiment of the present application, the negatively charged nanoparticles may be negatively charged silica.

[0025] In one embodiment of the present application, the D50 particle size of the negatively charged nanoparticles is 50nm-200nm. The appropriate nanoparticle size can increase the smoothing speed of the workpiece to be smoothed. Specifically, the D50 particle size of the negatively charged nanoparticles can be, but is not limited to, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 120nm, 140nm, or 160nm. In one embodiment of the present application, the D50 particle size of the negatively charged nanoparticles can be 50nm-100nm. In another embodiment of the present application, the D50 particle size of the negatively charged nanoparticles can be 120nm-200nm.

[0026] In one embodiment of the present application, the Zeta potential of the negatively charged nanoparticles is less than or equal to -20mV, which can further strengthen the electrostatic repulsive force with titanium nitride, accelerate the planarization speed of metal tungsten, improve the planarization effect, and reduce the residue of nanoparticles after the planarization process. Specifically, the Zeta potential of the negatively charged nanoparticles can be, but is not limited to, -20mV, -25mV, -30mV, -35mV, -40mV, -45mV or -50mV, etc. In one embodiment of the present application, the Zeta potential of the negatively charged nanoparticles can be from -20mV to -30mV. In another embodiment of the present application, the Zeta potential of the negatively charged nanoparticles can be from -30mV to -50mV.

[0027] In one embodiment of the present application, the mass percentage of negatively charged nanoparticles in the planarization composition is 0.01%-1%. An appropriate amount of negatively charged nanoparticles can increase the planarization speed, improve the planarization effect, and improve the production yield of semiconductor devices. Specifically, in the planarization composition, the mass percentage of negatively charged nanoparticles can be, but is not limited to, 0.01%, 0.02%, 0.03%, 0.05%, 0.08%, 0.1%, 0.2%, 0.5%, 0.8% or 1%, etc. In one embodiment of the present application, the mass percentage of negatively charged nanoparticles in the planarization composition can be 0.01%-0.5%. In another embodiment of the present application, the mass percentage of negatively charged nanoparticles in the planarization composition can be 0.2%-1%. In the present application, the negatively charged nanoparticles and their content in the planarization composition can be characterized by, but not limited to, titration, LC-MS (liquid chromatography-mass spectrometry), GC-MS (gas chromatography-mass spectrometry), infrared testing, nuclear magnetic resonance testing, and the like.

[0028] In the present application, the oxidizing agent can oxidize the surface of the tungsten metal to form a softened tungsten oxide layer, thereby promoting the removal of the tungsten metal and increasing the removal rate of the tungsten metal. Specifically, the oxidizing agent can include, but is not limited to, one or more of hydrogen peroxide, performic acid, peracetic acid, and peroxypropionic acid. In one embodiment of the present application, the oxidizing agent can be hydrogen peroxide. In another embodiment of the present application, the oxidizing agent can be peroxypropionic acid.

[0029] In one embodiment of the present application, in the leveling composition, the mass percentage of the oxidant is 0.1%-3%. An appropriate amount of oxidant can improve the softening effect of metal tungsten and promote the grinding and removal of the metal. Specifically, in the leveling composition, the mass percentage of the oxidant can be, but is not limited to, 0.1%, 0.5%, 0.8%, 1%, 1.2%, 1.4%, 1.8%, 2% or 3%, etc. In one embodiment of the present application, in the leveling composition, the mass percentage of the oxidant can be 0.1%-1.5%. In another embodiment of the present application, in the leveling composition, the mass percentage of the oxidant can be 1%-3%. In the present application, the oxidant and its content in the leveling composition can be characterized by, but is not limited to, titration, LC-MS (liquid chromatography-mass spectrometry), GC-MS (gas chromatography-mass spectrometry), infrared testing, nuclear magnetic resonance testing, and the like.

[0030] In the present application, the catalyst can promote the oxidation of the oxidant on the metal tungsten, increase the flattening speed of the metal tungsten, and enhance the flattening effect of the workpiece to be flattened. Specifically, the catalyst may include, but is not limited to, iron-containing compounds, which may include, but are not limited to, divalent iron compounds and trivalent iron compounds. For example, trivalent iron compounds may include, but are not limited to, ferrous nitrate, ferric gluconate, etc., and divalent iron compounds may include, but are not limited to, ferrous nitrate, ferric chloride, ferric sulfate, etc. In one embodiment of the present application, the catalyst may be ferric nitrate, and trivalent iron cations may exist in a free state in the aqueous solution, thereby promoting the oxidation of the oxidant.

[0031] In one embodiment of the present application, in the leveling composition, the mass percentage of the catalyst is 0.01%-1%, and an appropriate amount of catalyst can improve the softening effect of metal tungsten and promote the grinding and removal of the metal. Specifically, in the leveling composition, the mass percentage of the catalyst can be, but is not limited to, 0.01%, 0.05%, 0.08%, 0.1%, 0.2%, 0.4%, 0.8% or 1%, etc. In one embodiment of the present application, in the leveling composition, the mass percentage of the catalyst can be 0.01%-0.5%. In another embodiment of the present application, in the leveling composition, the mass percentage of the catalyst can be 0.2%-1%. In the present application, the catalyst and its content in the leveling composition can be characterized by, but is not limited to, titration, LC-MS (liquid chromatography-mass spectrometry), GC-MS (gas chromatography-mass spectrometry), infrared testing, nuclear magnetic resonance testing and other means.

[0032] In one embodiment of the present application, a corrosion inhibitor can reduce excessive corrosion of tungsten metal by other components in the planarization composition, prevent the formation of surface defects, and improve the planarization effect. Specifically, the corrosion inhibitor can include, but is not limited to, one or more of lysine, histidine, serine, and tyrosine. In one embodiment of the present application, the corrosion inhibitor can be lysine. In another embodiment of the present application, the corrosion inhibitor can be histidine.

[0033] In one embodiment of the present application, the mass percentage of the corrosion inhibitor in the leveling composition is 0.01%-1%. An appropriate amount of corrosion inhibitor can avoid excessive corrosion of metal tungsten. Specifically, in the leveling composition, the mass percentage of the corrosion inhibitor can be, but is not limited to, 0.01%, 0.05%, 0.08%, 0.1%, 0.2%, 0.4%, 0.8% or 1%. In one embodiment of the present application, the mass percentage of the corrosion inhibitor in the leveling composition can be 0.01%-0.5%. In another embodiment of the present application, the mass percentage of the corrosion inhibitor in the leveling composition can be 0.2%-1%. In the present application, the corrosion inhibitor and its content in the leveling composition can be characterized by, but are not limited to, titration, LC-MS (liquid chromatography-mass spectrometry), GC-MS (gas chromatography-mass spectrometry) infrared testing, nuclear magnetic resonance testing, and the like.

[0034] In one embodiment of the present application, the planarization composition further includes a silicon nitride modifier, which can further control the planarization speed of the silicon nitride, thereby adjusting the planarization speed selectivity ratio of titanium nitride and silicon nitride. Specifically, the silicon nitride modifier can include, but is not limited to, polyvinyl pyrrolidone and its derivatives.

[0035] In one embodiment of the present application, in the planarization composition, the mass percentage of the silicon nitride regulator is 0.01%-1%. An appropriate amount of silicon nitride regulator can achieve control of the planarization speed of silicon nitride, and can further strengthen the adjustment of the planarization speed selection ratio of titanium nitride and silicon nitride. Specifically, in the planarization composition, the mass percentage of the silicon nitride regulator can be, but is not limited to, 0.01%, 0.05%, 0.08%, 0.1%, 0.2%, 0.4%, 0.8% or 1%, etc. In one embodiment of the present application, in the planarization composition, the mass percentage of the silicon nitride regulator can be 0.01%-0.5%. In another embodiment of the present application, in the planarization composition, the mass percentage of the silicon nitride regulator can be 0.2%-1%. In the present application, the silicon nitride regulator and its content in the planarization composition can be characterized by, but not limited to, titration, LC-MS (liquid chromatography-mass spectrometry), GC-MS (gas chromatography-mass spectrometry), infrared testing, nuclear magnetic resonance testing, and the like.

[0036] This application also provides applications of the planarization composition. The planarization composition described in any of the above embodiments can be, but is not limited to, used in a planarization process. In one embodiment of this application, the planarization composition can be applied to a workpiece containing titanium nitride to achieve individual control of the planarization speed of the titanium nitride.

[0037] The present application also provides a planarization process, comprising: using a planarization composition to planarize a workpiece to be planarized, thereby obtaining a planarized workpiece. The planarization process provided by the present application can improve the planarization effect of the workpiece, reduce the planarization rate selectivity of titanium nitride and silicon nitride, and facilitate subsequent processes.

[0038] In one embodiment of the present application, the workpiece to be planarized is a substrate, which can be used in the preparation of semiconductor devices. The substrate surface can include silicon nitride, titanium nitride, oxide, and metal tungsten. The substrate is planarized using a planarization composition. The titanium nitride surface is connected to an organic carboxylic acid through coordination. The organic carboxylic acid that meets specific requirements can undergo primary dissociation to obtain negatively charged carboxylate radicals, which makes the titanium nitride surface negatively charged. This generates a strong electrostatic repulsion force with the negatively charged nanoparticles, reducing the planarization speed of the titanium nitride. At the same time, the combination of the components can achieve rapid removal of metal tungsten, oxide, and silicon nitride without affecting the planarization speed of the remaining surface components, thereby reducing the planarization speed selectivity of titanium nitride and silicon nitride.

[0039] In one embodiment of the present application, the selectivity ratio of the planarization speed of titanium nitride and silicon nitride is less than or equal to 10. The smaller the selectivity ratio, the higher the selectivity of the planarization composition for titanium nitride planarization, which can further reduce the planarization speed of titanium nitride, thereby improving the individual controllability of titanium nitride. Specifically, the selectivity ratio of the planarization speed of titanium nitride and silicon nitride can be, but is not limited to, 10, 9.5, 9, 8.5, 8, 7.5, 7, 6.5, 6, 5.5, 5, 4.5 or 4. In one embodiment of the present application, the selectivity ratio of the planarization speed of titanium nitride and silicon nitride can be 7-10. In another embodiment of the present application, the selectivity ratio of the planarization speed of titanium nitride and silicon nitride can be 2-8.

[0040] One embodiment of the present application provides a substrate produced by the planarization process described in any of the above embodiments. The substrate provided by the present application has a high degree of planarization, is individually controllable, has few surface defects, facilitates subsequent processing, and can improve the overall performance of semiconductor devices.

[0041] In one embodiment of the present application, the substrate includes a base material and a dielectric layer on the surface of the base material. The dielectric layer may be formed of, but is not limited to, one or more materials selected from the group consisting of silicon oxide, silicon nitride, aluminum oxide, a low-k material, and a metal material. In one embodiment of the present application, the dielectric layer may be composed of silicon oxide and silicon nitride. In another embodiment of the present application, the dielectric layer may be composed of silicon oxide, silicon nitride, and metal tungsten.

[0042] In one embodiment of the present application, the substrate is selected based on actual needs. Specifically, the substrate may be, but is not limited to, a silicon wafer or a silicon wafer covered with a coating. For example, the coating may be an anti-reflective coating, an anti-etching coating, an epitaxial layer, a metal layer, a dielectric layer, a modified layer, or a supporting layer. Usually, other coatings can be obtained by pre-treating the substrate. The pre-treatment method can be: subjecting the silicon wafer substrate to O2 plasma surface hydrophilic activation; or cleaning in Piranha solution (H2O: 30% ammonia water: 30% H2O2 = 5:1:1) for 15 minutes to 20 minutes, and then washing with deionized water and isopropyl alcohol to complete the hydrophilic treatment; or using evaporation or spin coating to cover the substrate with hexamethyldisilazane (Hexamethyldisilazane, HMDS) to perform surface hydrophobic treatment on the substrate; the hydrophobic treatment can be after the hydrophilic treatment; or adding a bottom antireflection coating (BARC), a bottom carbon-containing coating (SOC), or a bottom silicon-containing coating (SOG).

[0043] In one embodiment of the present application, a substrate to be planarized is planarized using the planarization composition described in any of the above embodiments to remove surface irregularities on the substrate, followed by overall thinning to obtain a flat substrate. This substrate exhibits a high degree of surface planarization and minimal surface defects, resulting in electronic devices fabricated using this substrate exhibiting excellent overall performance.

[0044] In one embodiment of the present application, a patterned substrate is provided, and a preparation method thereof comprises: forming a patterned film on the surface of the substrate described in the above embodiment, and transferring the pattern of the patterned film to the substrate to obtain a patterned substrate.

[0045] In one embodiment of the present application, the pattern formed by the photosensitive material film selectively protects the underlying substrate material during the etching step. Under certain etching conditions, the unprotected substrate material is etched, but the protected area is etched more slowly than the unprotected area, ultimately forming a pattern on the substrate material, thereby transferring the pattern to the substrate. Specifically, the etching process can be performed by HF etching, ion etching, or ion implantation to transfer the pattern to the substrate.

[0046] The present application provides a semiconductor device, which is manufactured using the substrate described in any of the above embodiments, or the patterned substrate described in any of the above embodiments. The semiconductor device provided by the present application has high precision, which is conducive to improving the overall performance of the semiconductor device.

[0047] In one embodiment of the present application, the semiconductor device comprises: a structure obtained by etching or electron injection into a patterned substrate. In one embodiment of the present application, the semiconductor device is a structure obtained by etching or electron injection into a patterned substrate, the substrate being a silicon wafer.

[0048] In this application, there is no limitation on the specific type of semiconductor device. In one embodiment of this application, the semiconductor device may be an integrated circuit device such as a chip. During the chip preparation process, other functional layers may be prepared after completing the aforementioned patterning process.

[0049] The effects of the technical solution of this application are further illustrated below through specific examples.

[0050] Example 1

[0051] The planarization composition includes 0.25% by mass of negatively charged silicon dioxide (Zeta potential of -30 mV), 0.5% by mass of oxidizing agent hydrogen peroxide, 0.06% by mass of catalyst ferric nitrate, 0.05% by mass of corrosion inhibitor L-lysine, 0.5% by mass of titanium nitride regulator malonic acid (pKa1 of 2.82, pKa2 of 5.66), and the balance is solvent water. The pH of the planarization composition is 3.

[0052] Example 2

[0053] The difference from Example 1 is that the mass percentage of the titanium nitride regulator is 0.1%.

[0054] Example 3

[0055] The difference from Example 1 is that the mass percentage of the titanium nitride regulator is 1%.

[0056] Example 4

[0057] The difference from Example 1 is that the mass percentage of the titanium nitride regulator (citric acid, pKa1 is 3.13, pKa2 is 4.76) is 0.2%.

[0058] Example 5

[0059] The difference from Example 1 is that the pH of the planarization composition is 2, and the titanium nitride regulator is oxalic acid (pKa1 is 1.23, pKa2 is 4.19).

[0060] Example 6

[0061] The difference from Example 1 is that the pH of the planarization composition is 4.8, and the titanium nitride regulator is azelaic acid (pKa1 is 4.55, pKa2 is 5.4).

[0062] Example 7

[0063] The difference from Example 1 is that the mass percentage of negatively charged silicon dioxide (Zeta potential of -20 mV) is 0.01%.

[0064] Example 8

[0065] The difference from Example 1 is that the mass percentage of negatively charged silicon dioxide (Zeta potential of -25 mV) is 1%.

[0066] Example 9

[0067] The difference from Example 1 is that the mass percentage of the corrosion inhibitor L-lysine is 0.01%.

[0068] Example 10

[0069] The difference from Example 1 is that the mass percentage of the corrosion inhibitor L-lysine is 1%.

[0070] Comparative Example 1

[0071] The difference from Example 1 is that no titanium nitride regulator is added.

[0072] Comparative Example 2

[0073] The difference from Example 1 is that the mass percentage of the titanium nitride regulator (succinic acid, pKa1 is 4.21, pKa2 is 5.64) is 0.2%.

[0074] Comparative Example 3

[0075] The difference from Example 1 is that the mass percentage of the titanium nitride regulator (glutaric acid, pKa1 is 3.77, pKa2 is 6.08) is 0.2%.

[0076] Performance testing

[0077] The 12-inch cleaned substrates obtained in Examples 1-10 and Comparative Examples 1-3 were planarized to determine the planarization rate. The test procedure was as follows: a fully automatic CMP polishing apparatus (Huahai Qingke 300D) was used, with a two-layer polishing pad and a diamond pad conditioner. The polishing pressure was set to 1 psi, the polishing table speed was set to 63 rpm, the polishing head speed was set to 60 rpm, and the abrasive supply rate was set to 200 ml / min. The test results are shown in Table 1.

[0078] Table 1 Performance test of planarization composition

[0079]

[0080] According to Examples 1 to 10 and Comparative Examples 1 to 3 provided herein, it can be seen that when the planarization composition provided herein is used for planarization of workpieces containing titanium nitride and silicon nitride, the planarization speed of titanium nitride can be individually regulated, the planarization speed selectivity of titanium nitride and silicon nitride can be reduced, the stability of the preparation process of semiconductor devices can be improved, and the overall performance of semiconductor devices can be improved. According to Examples 1 and 2 to 6, it can be seen that the pH of the suitable titanium nitride regulator and the planarization composition, the greater the difference between the first dissociation constant of the organic carboxylic acid and the pH value of the planarization composition and 0.5, the further the individual regulation capability of the titanium nitride planarization speed can be improved, and the planarization speed selectivity of titanium nitride and silicon nitride can be reduced. According to Example 1 and Comparative Examples 1 to 3, it can be seen that only a titanium nitride regulator that simultaneously satisfies the specific conditions of the first dissociation constant, the second dissociation constant, and the pH of the planarization composition can achieve individual regulation of the titanium nitride planarization speed and reduce the planarization speed selectivity of titanium nitride and silicon nitride.

[0081] It should be understood that the first, second and various numerical numbers involved in this document are only distinguished for the convenience of description and are not intended to limit the scope of this application.

[0082] In this application, "and / or" describes the relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the related objects are in an "or" relationship.

[0083] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0084] In this application, “-” represents a range value, including the endpoint values ​​at both ends. For example, the value of a can be 0.5-15, which means that the value of a can be between 0.5 and 15, and includes the endpoint values ​​0.5 and 15.

[0085] The above is a preferred embodiment of the present application, but it should not be construed as limiting the scope of the present application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present application, and such improvements and modifications are also considered to be within the scope of protection of the present application.

Claims

1. A planarization composition, characterized in that: The planarization composition includes negatively charged nanoparticles, an oxidizer, a catalyst, a corrosion inhibitor, a titanium nitride regulator and a solvent. The titanium nitride regulator includes an organic carboxylic acid. The first dissociation constant pKa1 of the organic carboxylic acid is less than or equal to the sum of the pH value of the planarization composition and 0.5, and the second dissociation constant pKa2 of the organic carboxylic acid is greater than or equal to the sum of the pH value of the planarization composition and 0.

5.

2. The planarization composition according to claim 1, wherein The organic carboxylic acid includes two or more carboxyl groups, and the organic carboxylic acid includes one or more of tartaric acid, citric acid, malonic acid, glutaric acid, succinic acid and azelaic acid.

3. The planarization composition according to claim 1, wherein The pH value of the planarizing composition is 2-5.

4. The planarization composition according to claim 1, wherein The zeta potential of the negatively charged nanoparticles is less than or equal to -20 mV, and the negatively charged nanoparticles include one or more of natural abrasives and abrasives containing modified groups.

5. The planarization composition according to claim 1, wherein The oxidant comprises one or more of hydrogen peroxide, performic acid, peracetic acid, and peroxypropionic acid; and / or, The catalyst comprises an iron-containing compound; and / or, The corrosion inhibitor includes amino acids, and the amino acids include one or more of lysine, histidine, serine, and tyrosine.

6. The planarization composition according to claim 1, wherein In the planarization composition, the mass percentage of the negatively charged nanoparticles is 0.01%-1%; and / or, The mass percentage of the oxidant is 0.1%-3%; and / or, The mass percentage of the catalyst is 0.01%-1%; and / or, The mass percentage of the corrosion inhibitor is 0.01%-1%; and / or, The mass percentage of the titanium nitride regulator is 0.1%-1%.

7. The planarization composition according to claim 1, wherein The planarization composition further includes a silicon nitride regulator, which includes polyvinyl pyrrolidone and its derivatives.

8. The planarization composition according to claim 7, wherein In the planarization composition, the mass percentage of the silicon nitride regulator is 0.001%-0.1%.

9. A planarization process, characterized in that: include: A workpiece to be flattened is flattened using the flattening composition according to any one of claims 1 to 8 to obtain a flattened workpiece.

10. The planarization process according to claim 9, wherein: The surface of the workpiece to be planarized comprises titanium nitride and silicon nitride, and a planarization speed selection ratio of the titanium nitride to the silicon nitride is less than or equal to 10.

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