Planarization method of mixed bonding structure and planarization apparatus of mixed bonding structure

Abstract

The present invention relates to a mixed bonding structure planarization method and a mixed bonding structure planarization apparatus, and according to the present invention, there is provided a mixed bonding structure planarization method and a mixed bonding structure planarization apparatus, and in a semiconductor and display manufacturing process, a recess required in a mixed bonding process between bonding portions can be formed in a suitable shape without rounding due to excessive polishing of an oxide film, and polishing residues present on the surface of the oxide film and a metal layer are removed.

Description

Technical Field

[0001] This invention relates to a planarization method and apparatus for a hybrid bonding structure, and more specifically, to a planarization method and apparatus for a hybrid bonding structure. In semiconductor and display fabrication processes, it can form recesses required for the hybrid bonding process between joints in a suitable shape without causing rounding due to excessive polishing of the oxide film, while removing polishing residues present on the surfaces of the oxide film and metal layer. Background Technology

[0002] In semiconductor and display manufacturing processes, chemical mechanical polishing (CMP) is also known as planarization. It refers to the process of removing part of the barrier metal (hereinafter referred to as "metal layer") by combining physical processes (such as abrasion) and chemical processes (such as oxidation or chelation) to form a recess.

[0003] The CMP process uses pads, slurry, and a dressing device. The pads provide mechanical force through the pressure of the carrier and can evenly transfer the slurry to the wafer surface through grooves and pores.

[0004] The pads are made of polyurethane and are classified according to their application, with the slurries being divided into those for oxides and those for metals. When polishing metals, acids and oxidants are used to oxidize the surface, while when polishing oxides, components that can form hydroxides on the surface are used.

[0005] The slurry particles are very small, about 0.1 μm in size. If they clump together, they can cause scratches. Therefore, stirring is used to maintain the integrity of the slurry.

[0006] Because glazing residue accumulates on the pad surface, reducing the removal capacity of the trimmer, diamond abrasive is used to manually scrape off the pad surface with accumulated glazing residue, restoring it to its original state.

[0007] Specifically, the CMP process is performed by using a polishing slurry composition with active chemical properties on a polishing pad that rubs the surface of a semiconductor wafer. The polishing particles contained in the polishing slurry composition and the surface protrusions of the polishing pad can generate mechanical friction with the surface of the semiconductor wafer, while effectively removing excess material used when forming layers by mechanical polishing.

[0008] The chemical components contained in the polishing slurry composition induce a selective chemical reaction on the semiconductor wafer surface while selectively removing the semiconductor wafer surface.

[0009] Following the CMP process, particulate contaminants are generated. These contaminants originate from residues produced during the CMP process or from the removed layers. These residues or contaminants can induce wiring damage in various subsequent processes, such as metal wiring or formation, etching, or hybrid bonding (die-to-die, die-to-wafer, or wafer-to-wafer recessed bonding, etc.), leading to surface damage and directly causing poor electrical performance of semiconductor devices. Therefore, a cleaning process is necessary as a subsequent step to remove the large amount of polishing residue present on the oxide film (oxide film layer surface) and metal layer surface.

[0010] The CMP process is applicable to hybrid bonding.

[0011] Hybrid bonding is a difficult technique to control because it uses pressure and heat to bond the dielectrics and thermal expansion to bond the metals, so it should be possible to bond them without affecting each other.

[0012] Therefore, due to its high conductivity and excellent electromigration resistance, copper is widely used in mixed bonding preparation, and the dielectric can be an oxide film (such as SiO2).

[0013] Typically, hybrid bonding processes include copper pad formation and bonding steps. Holes in integrated circuits often have high aspect ratios. To fill these deep holes without seams or voids, a thick layer of copper is deposited on the substrate surface. Therefore, removing this copper layer requires a CMP (Continuous Metal Processing) process.

[0014] Because this CMP process utilizes the selectivity between two materials with different removal rates, dishing inevitably occurs in the target film after the CMP process. For example, in metal CMP, when depositing a metal layer between oxide films, initially only the metal layer is polished, but at some point, the faster-removing metal layer is removed more than the oxide film, thus forming a so-called rounding structure, which can lead to an increase in metal resistance.

[0015] Therefore, when a recess is formed between the joints required for hybrid bonding, a chamfered structure is formed due to the over-polishing of the oxide film, which can effectively remove polishing residues on the oxide film and metal layer surfaces. Thus, it is necessary to develop a technology to solve the problem of increased metal resistance and improve the bonding force in the hybrid bonding process.

[0016] Existing technical documents Patent documents Korean Patent Publication No. 2022-0058414 Summary of the Invention The problem the invention aims to solve In order to solve the problems of the prior art as described above, the object of the present invention is to provide a new method and apparatus for planarizing hybrid bond structures.

[0017] Furthermore, the present invention aims to provide a planarization method and apparatus for a hybrid bonding structure, which forms the required recess in the hybrid bonding process between the joints in a suitable shape without causing rounding due to excessive polishing of the oxide film, while suppressing the etching of the oxide film on the surface of the oxide film and the metal layer, thereby suppressing the rounding phenomenon based on excessive polishing, and simultaneously improving etching ability and cleaning ability, thereby being able to clean polishing residues on the surface of the oxide film and the metal layer, and providing excellent hybrid bonding force.

[0018] The objectives and other objectives of this invention can be achieved by the invention as described below.

[0019] means for solving problems To achieve the above objectives, the present invention provides a method for planarizing hybrid bonding structures.

[0020] II) In the first step, the hybrid bonding structure includes: a substrate; a hole formed in a recessed region of the substrate; an oxide layer formed in the recessed region and a non-recessed region of the substrate, respectively; a barrier layer formed on the bottom and sidewalls of the hole and on the oxide layer; and a metal layer formed in the hole and on the barrier layer.

[0021] III) In the above steps I) to II), the planarization method of the hybrid bonding structure includes: a first step of removing a metal layer formed on a non-recessed area of ​​the substrate; a second step of removing metal layer residue, oxide layer and barrier layer formed on the oxide layer on the non-recessed area; a third step of planarizing the step difference between the metal layer and oxide film layer formed in the hole; and a fourth step of removing the barrier layer formed on the bottom and sidewall of the hole, while forming a metal thermal expansion space in a planar form.

[0022] IV) In statements I) to III), the material of the metal layer may be copper.

[0023] V) In all of I) to IV), the material of the barrier layer may include one or more selected from Ti, TiN, Ta and TaN.

[0024] VI) In all of I) to V), the material of the oxide layer may include one or more selected from Si, SiO2 and SiCN.

[0025] VII) In I) to VI), the metal layer removed in the first step may be all the metal layers deposited on the non-recessed area and part of the metal layer formed inside the hole.

[0026] VIII) In steps I) to VII), the first step, the second step, and the third step can be performed by a CMP process.

[0027] IX) In steps I) to VIII), the second and third steps can be performed simultaneously.

[0028] X) In steps I) to IX), the second and third steps can be performed by using a slurry with a polishing speed selection ratio of oxide layer to metal layer adjusted to 1:1.

[0029] XI) In the 1) to X) statements, the slurry may contain polishing particles, corrosion inhibitors, complexing agents and oxidants.

[0030] XII) In the 1) to XI) of the above, the slurry may contain 0.05wt% to 5wt% silica particles, 0.001wt% to 1wt% azole-based corrosion inhibitor containing one or more N groups, 0.001wt% to 0.5wt% amino acid complexing agent, 0.05wt% to 1wt% oxidizing agent, and the balance being water.

[0031] XIII) In steps I) to XII), the fourth step may be performed by filling the recessed areas of the substrate with an etching cleaning solution composition.

[0032] XIV) In the fourth step, after filling with the etching cleaning solution composition, step e may be further included: filling the recessed area of ​​the substrate with DW (deionized water).

[0033] XV) In the cases described in I) to XIV), the etching cleaning solution composition and DW may be filled using one or more pads and brushes selected independently from each other.

[0034] XVI) In the cases of I) to XV), the etching cleaning solution composition may be an alkaline solution containing an etching substance, a metal corrosion inhibitor, a silicon film anti-etching agent, a hydroxyl-containing alkaline compound, and an alkanolamine-containing compound.

[0035] XVII) In the cases of I) to XVI), the etching material may be a compound containing carboxyl groups to selectively etch copper or titanium.

[0036] XVIII) In the above I) to XVII), as an example, the etching substance may be one or more selected from asparagine, ammonium citrate, glycine, arginine, histidine, lysine, alanine, citric acid, aspartic acid and glutamic acid. As a specific example, it may be ammonium citrate and citric acid, etc.

[0037] XIX) In the cases described in I) to XVIII), the etching material may contain 0.1% to 10% by weight, based on the total weight of the etching cleaning liquid composition.

[0038] In the cases described in I) to XIX), the metal corrosion inhibitor may be a compound containing functional groups with high reducing power to prevent corrosion of copper or titanium.

[0039] XXI) In the above I) to XX), the silicon film etch resist agent can be a compound containing sulfonic acid groups used to prevent the etching of silicon oxide films (silicon, silicon oxide film, silicon nitride film and silicon carbonitride film, etc.).

[0040] XXII) In the I) to XXI), the alkaline compound containing hydroxyl groups may be a compound that adjusts the pH of the etching cleaning solution composition to 8 or higher.

[0041] In XXIII of the above (I) to XXII), the pH value of the etching cleaning solution composition may be in the range of 8 to 14.

[0042] XXIV) In the cases described in I) to XXIII), the fourth step may be carried out by chemical impregnation or physical washing.

[0043] In XXV) of XXIV), the etching cleaning solution composition can be used to planarize the metal layer included in the hole by etching at an etching rate of less than 50 Å / min.

[0044] XXVI) In the 1) to XXV) cases, the etching cleaning solution composition can remove polishing residues present on the oxide layer and metal layer surfaces.

[0045] XXVII) In XXVI) of the above, the hybrid bonding structure planarization process may include, after the fourth step, a step of activating the surface with a pulse mode; a step of pre-bonding the die and wafer; and a step of densely bonding the bonding structure between the die and the wafer by thermal expansion.

[0046] In addition, the present invention provides a planarization device for a hybrid bonding structure (XXVIII).

[0047] In XXIX, the hybrid bonding structure in XXVIII includes: a substrate; a hole formed in a recessed region of the substrate; an oxide layer formed in the recessed region and a non-recessed region of the substrate, respectively; a barrier layer formed on the bottom and sidewalls of the hole and on the oxide layer; and a metal layer formed in the hole and on the barrier layer.

[0048] In XXX, the planarization device for the hybrid bonding structure in XXVIII) to XXIX) includes: at least two CMP modules; and an etching cleaning module.

[0049] In XXXI), at least two CMP modules are used to perform a chemical mechanical polishing process on the substrate to remove the metal layer on the non-recessed areas. The second or more of the two or more CMP modules can be used to planarize the step difference between the metal layer and oxide film layer formed within the hole by using a slurry with a polishing speed selection ratio of oxide layer to metal layer adjusted to 1:1.

[0050] XXXII) In XXVIII) to XXXI), the etching cleaning module can be used to remove the barrier layer formed on the bottom and sidewalls of the hole by filling the recessed area of ​​the substrate with an etching cleaning liquid composition, while forming a metal thermal expansion space in a flat form.

[0051] In XXXIII), the planarization device for the hybrid bonding structure may further include a DW cleaning module.

[0052] In XXXIV), the DW cleaning module can function after the etching cleaning module.

[0053] In XXXV), the etching cleaning module can be a pad module or a brush module.

[0054] In XXXVI), the DW cleaning module can be a brush module in XXVIII) to XXXV).

[0055] XXXVII) In XXVIII) to XXXVI), the planarization device for the hybrid bonding structure may consist of a first CMP module, a second CMP module, and an etching cleaning pad module.

[0056] In XXXVIII), the first CMP module, the second CMP module, and the etching cleaning pad module can be configured as continuous or batch.

[0057] In XXXIX), the planarization device for the hybrid bonding structure in XXVIII) to XXXVIII) may consist of a first CMP module, a second CMP module, a third CMP module, and an etching cleaning brush module.

[0058] In XXVIII) to XXXIX), the first CMP module, the second CMP module, the third CMP module, and the etching cleaning brush module can be configured as continuous or batch.

[0059] In XLI) of XXVIII) to XL), the planarization device for the hybrid bonding structure may consist of a first CMP module, a second CMP module, an etching cleaning pad module, and an etching cleaning brush module.

[0060] In XLII), the first CMP module, the second CMP module, the etching cleaning pad module, and the etching cleaning brush module can be configured as continuous or batch.

[0061] In XXVIII) to XLII), the planarization device for the hybrid bonding structure may consist of a first CMP module, a second CMP module, an etching cleaning pad module, and a DW cleaning brush module.

[0062] In XXVIII) to XLIII), the first CMP module, the second CMP module, the etching cleaning pad module, and the DW cleaning brush module can be configured as continuous or batch.

[0063] In XLV) of XXVIII) to XLIV), the planarization device for the hybrid bonding structure may include a pulse mode, a pre-bonding device, and a thermal expansion device.

[0064] Invention Effects According to the present invention, compared with the existing hybrid bond structure planarization technology that uses CMP process to remove metal layers and barrier layers on non-recessed areas, the removal of metal layers and barrier layers on non-recessed areas and the flat maintenance of metal layers within the holes improves the uniformity of metal layer dishing and reduces metal resistance. Even without the use of precision equipment, it has the effect of reducing process costs through parallel chemical processing. Attached Figure Description

[0065] Figure 1This is a schematic cross-sectional view illustrating a hybrid bonding structure between planarization steps in an embodiment of the present invention.

[0066] Figure 2 This is a cross-sectional view showing a planarized hybrid bonding structure according to an implementation example of the present invention.

[0067] Figure 3 This is a cross-sectional view illustrating the rounding phenomenon of the planarization process of the prior art hybrid bonding structure and the voids generated during the hybrid bonding process. Figure 3 The basic process refers to the "bulk process," while the polishing process refers to the "buffing process."

[0068] Figure 4 is a flowchart illustrating four embodiments of the hybrid bonding structure planarization process of the present invention.

[0069] Figure 5 is a schematic diagram and flowchart illustrating the operation of the planarization apparatus for each of the four embodiments of the present invention in Figure 4, while also briefly showing the changes in the planarization structure at each step.

[0070] Explanation of reference numerals in the attached figures 101: Substrate 102: Kong 103: Oxide layer 104: Barrier layer 105: Metal layer 1001: CMP Module 1003: Etching Cleaning Module 1005: DW Cleaning Module 1007: Pad Module 1009: Flashing Modules Detailed Implementation The present invention will now be described in detail with reference to the accompanying drawings, but the present invention is not limited thereto.

[0071] Unless otherwise stated, the term "hybrid bonded product" as used in this invention refers to semiconductor products or display products, etc., that undergo subsequent hybrid bonding processes.

[0072] Unless otherwise stated, the term "etching cleaning composition" as used in this invention refers to a composition that can simultaneously etch and clean semiconductor products or display products that are subsequently subjected to mixed bonding processes, but is not limited to its use in etching or cleaning processes alone.

[0073] Unless otherwise stated, the term "oxide layer" as used in this invention refers to a dielectric.

[0074] In the process of researching planarization methods and apparatuses for hybrid bonding structures (which, in semiconductor and display fabrication processes, can form recesses required in the hybrid bonding process between joints in a suitable shape without rounding due to excessive polishing of the oxide film, and simultaneously remove polishing residues on the surfaces of the oxide film and metal layer), the inventors confirmed that the above-mentioned objectives can be achieved by using a slurry and etching cleaning solution composition with a specific composition and designing the planarization process and apparatus. Based on this, the present invention was completed.

[0075] The sequence of processes for forming hybrid bonding structures typically includes the following steps.

[0076] Silicon is selected as the material for substrate 101, and holes 102 are formed on substrate 101 by etching. Silicon dioxide or SiCN is selected as the material for oxide layer 103, and oxide layer 103 is deposited on substrate 101 by chemical vapor deposition (CVD). Titanium is selected as the material for barrier layer 104, and barrier layer 104 is deposited on oxide layer 103, bottom and sidewalls of holes 102 by physical vapor deposition (PVD). Copper is selected as the material for metal layer 105, and metal layer 105 is deposited on holes 102 by electrochemical electroplating.

[0077] The via 102 of the hybrid bonding structure has a high aspect ratio. In order to deposit a metal layer 105 in the via 102 in a void-free form, a thick upper deposited metal layer 105 is deposited on the barrier layer 104 by electrochemical electroplating. As follows Figure 1 As shown, the hybrid bonding structure prior to the planarization process is illustrated.

[0078] The thickness of the metal layer 105 deposited on the non-recessed area can typically be from about 0.5 μm to 5 μm, but is not specific to this and can vary depending on the application.

[0079] After depositing the metal layer 105 in the hole 102 and on the non-recessed area, the next step is to remove the metal layer 105 and the barrier layer 104 deposited on the non-recessed area.

[0080] A planarization process for removing the hybrid bonding structure of the metal layer 105 and the barrier layer 104 formed on the non-recessed area in one embodiment of the present invention may include the following steps.

[0081] First step: Remove the metal layer 105 formed on the non-recessed area of ​​the substrate by chemical mechanical polishing (CMP).

[0082] The metal layer 105 may be all the metal layers formed on the non-recessed area and part of the metal layer formed inside the hole 102.

[0083] The chemical substances used in the CMP process may vary depending on processes P1, P2, and P3. For P1, a slurry with a high Cu polishing rate is used to remove the metal layer 105 formed on the non-recessed areas. For processes P2 and P3, a slurry with a Cu:Ox selection ratio of 1:1 is suitable.

[0084] The substrate is fixed to the head and rotates together with the chuck. The platen at the lower end of the CMP rotates in the same direction as the aforementioned rotation. As an example, when the rotation speed is 40 RPM to 90 RPM, the barrier layer can be effectively removed.

[0085] The second step involves removing the metal layer residue, oxide layer, and barrier layer formed on the oxide layer from the non-recessed area. The thickness of the barrier layer 104 on the non-recessed area can be approximately 1 nm to 15 nm, but may vary depending on the process.

[0086] The material of the barrier layer 104 may include one or more selected from Ti, TiN, Ta, and TaN, but is not limited thereto. Furthermore, the chemical substances used to remove the barrier layer can be applied using a slurry with a polishing speed selection ratio of oxide layer to metal layer adjusted to 1:1.

[0087] After the barrier layer 104 is removed from the non-recessed areas, the oxide layer 103 beneath the barrier layer 104 is exposed.

[0088] The material of the oxide layer 103 may include one or more selected from Si, SiO2, and SiCN, but is not limited thereto. In addition, the thickness of the oxide layer 103 may be from about 0.01 μm to 1 μm, but this may vary depending on the process.

[0089] The slurry used to remove the barrier layer may contain polishing particles, corrosion inhibitors, complexing agents, and oxidants. The slurry may contain 0.05 wt% to 5 wt% silica particles, 0.001 wt% to 1 wt% azole corrosion inhibitors containing one or more N groups, 0.001 wt% to 0.5 wt% amino acid complexing agents, and 0.05 wt% to 1 wt% oxidants. Under these conditions, the barrier layer can be effectively removed.

[0090] The substrate is fixed to the head and rotates together with the chuck. The platen at the lower end of the CMP rotates in the same direction as the aforementioned rotation. As an example, when the rotation speed is 40 RPM to 90 RPM, the barrier layer can be effectively removed.

[0091] The third step: flatten the step difference between the metal layer and oxide film layer formed in the hole.

[0092] For planarizing the metal layer 105 formed within the hole, in particular, the slurry for planarizing the upper metal layer may contain polishing particles, corrosion inhibitors, complexing agents, and oxidants. The slurry may contain 0.05wt% to 5wt% silica particles, 0.001wt% to 1wt% azole corrosion inhibitors containing one or more N groups, 0.001wt% to 0.5wt% amino acid complexing agents, and 0.05wt% to 1wt% oxidants. In this case, the metal layer can be effectively planarized.

[0093] To achieve a flat upper surface, the step difference between the metal layer 105 and the oxide film layer within the hole 102 can be recovered using a CMP process to achieve planarization. Specifically, the metal layer 105 and the oxide film layer are partially polished in the same manner to remove the step difference.

[0094] The roughness of the metal layer 105 inside the hole 102 can be recovered through the CMP process to achieve planarization.

[0095] Typically, the thickness of the upper part of the metal layer 105 can be less than 50 Å.

[0096] Fourth step: Remove the barrier layer formed on the bottom and sidewalls of the hole while simultaneously creating a flat space for thermal expansion of the metal.

[0097] In order to remove the barrier layer formed on the bottom and sidewalls of the hole while creating a flat space for thermal expansion of the metal, an etching cleaning process is preferred.

[0098] The chemical substances used in the etching cleaning process may be an etching cleaning solution composition.

[0099] The etching cleaning solution composition is characterized in that it is an alkaline solution containing an etching substance, a metal corrosion inhibitor, a silicon film anti-etching agent, an alkaline compound containing hydroxyl groups, and an alkanolamine compound. In this case, it inhibits the rounding phenomenon based on over-polishing by inhibiting the etching of the oxide film, and at the same time improves the etching ability and cleaning ability, thereby having the effect of cleaning polishing residues present on the surface of the oxide film and the metal layer.

[0100] Specifically, in the etching cleaning solution composition of the present invention, the etching substance may be a compound containing carboxyl groups and selectively etching copper or titanium.

[0101] The etching material may be a compound containing carboxyl groups that selectively etches copper or titanium.

[0102] As an example, the etching substance may be selected from one or more of asparagine, ammonium citrate, glycine, arginine, histidine, lysine, alanine, citric acid, aspartic acid and glutamic acid. As a specific example, it may be ammonium citrate and citric acid, etc.

[0103] The metal corrosion inhibitor may be a compound containing functional groups with high reducing power and used to prevent corrosion of copper or titanium.

[0104] The silicon film anti-etching agent can be a compound containing sulfonic acid groups used to prevent etching of silicon oxide films (silicon, silicon oxide film, silicon nitride film, and silicon carbonitride film, etc.).

[0105] The alkaline compound containing hydroxyl groups may be a compound that adjusts the pH of the etching cleaning solution composition to above 8.

[0106] The etching substance may be selected from one or more of asparagine, ammonium citrate, glycine, arginine, histidine, lysine, alanine, citric acid, aspartic acid, and glutamic acid.

[0107] Based on the total weight of the etching cleaning fluid composition, as an example, the etching substance may contain 0.1% to 10% by weight, and as a specific example, it may contain 1% to 10% by weight.

[0108] The metal corrosion inhibitor may be selected from one or more of gallic acid, mercaptosuccinic acid, resorcinol, uric acid, vanillic acid, fructose, kojic acid, 5-aminosalicylic acid, and dextrose.

[0109] Based on the total weight of the etching cleaning fluid composition, the metal corrosion inhibitor may contain 0.1% to 10% by weight.

[0110] The silicon film etch resist agent may be selected from one or more of benzenesulfonic acid, aminosulfonic acid, 2,4-dimethylbenzenesulfonic acid, 4-hydroxypyridine-3-sulfonic acid, p-toluenesulfonic acid, ammonium aminosulfonate, and methanesulfonic acid.

[0111] Based on the total weight of the etching cleaning fluid composition, the silicon film anti-etching agent may contain 0.001% to 30% by weight.

[0112] The basic compound containing hydroxyl groups may be selected from one or more of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, ammonium hydroxide, choline hydroxide, sodium hydroxide, and potassium hydroxide.

[0113] Based on the total weight of the etching cleaning fluid composition, the alkaline compound containing hydroxyl groups may contain 1% to 25% by weight.

[0114] The alkanolamine compound may be selected from one or more of propanolamine, ethanolamine, diethanolamine, triethanolamine, 2-2-(ethylamino)ethanol, 1-amino-2-propanol, 2-(methylamino)ethanol, N,N-dimethylethanolamine, 1,3-diamino-2-propanol, 2-amino-1,3-propanediol and 2-amino-2-methyl-1-propanol.

[0115] Based on the total weight of the etching cleaning fluid composition, the alkanolamine compound may contain 0.1% to 10% by weight.

[0116] The etching cleaning solution composition may contain a surfactant.

[0117] The surfactant may be selected from one or more nonionic surfactants and anionic surfactants.

[0118] Based on the total weight of the etching cleaning fluid composition, the surfactant may be contained in the range of 0.001% by weight to 3% by weight.

[0119] In the etching cleaning solution composition of the present invention, based on the total weight of the etching cleaning solution composition, as an example, the etching substance may contain 0.1% to 10% by weight, as a specific example, 1% to 10% by weight, and as a preferred example, 1% to 5% by weight. In this case, the rounding phenomenon based on over-polishing can be suppressed by suppressing the etching of the oxide film, while simultaneously improving etching and cleaning capabilities. This enables the cleaning of polishing residues present on the oxide film and metal layer surfaces, and does not adversely affect the etching cleaning solution composition that provides excellent bonding strength during the hybrid bonding process, while providing a recess in a suitable shape at the joint required for hybrid bonding.

[0120] In the etching cleaning solution composition of the present invention, the metal corrosion inhibitor may be a compound containing functional groups with high reducing power and used to prevent corrosion of copper or titanium.

[0121] As an example, the metal preservative may be selected from one or more of gallic acid, mercaptosuccinic acid, resorcinol, uric acid, vanillic acid, fructose, kojic acid, 5-aminosalicylic acid and dextrose. As a specific example, it may be uric acid and ascorbic acid, etc.

[0122] Based on the total weight of the etching cleaning solution composition, as an example, the metal corrosion inhibitor may contain 0.1% to 10% by weight, as a specific example, 0.1% to 5% by weight, and as a preferred example, 0.1% to 3% by weight. In this case, rounding based on over-polishing can be suppressed by inhibiting the etching of the oxide film, while simultaneously improving etching and cleaning capabilities to clean polishing residues present on the oxide film and metal layer surfaces. Furthermore, the etching cleaning solution composition does not adversely affect the effect of achieving excellent bonding strength in the hybrid bonding process, while providing a recess in a suitable shape at the joint required for hybrid bonding.

[0123] In the etching cleaning liquid composition of the present invention, the silicon film anti-etching agent may be a compound containing sulfonic acid groups and used to prevent silicon film etching.

[0124] As an example, the silicon film etchant may be selected from one or more of benzenesulfonic acid, aminosulfonic acid, 2,4-dimethylbenzenesulfonic acid, 4-hydroxypyridine-3-sulfonic acid, p-toluenesulfonic acid, ammonium aminosulfonate and methanesulfonic acid. As a specific example, it may be methanesulfonic acid, but it is not limited thereto.

[0125] Based on the total weight of the etching cleaning solution composition, as an example, the silicon film etchant may contain 0.001% to 30% by weight, as a specific example, 0.1% to 5% by weight, and as a preferred example, 0.1% to 3% by weight. In this case, both etching and cleaning capabilities are improved to clean polishing residues present on the oxide film and metal layer surfaces, and the etching cleaning solution composition does not adversely affect the achievement of excellent bonding strength in the hybrid bonding process. Simultaneously, it can prevent rounding caused by over-polishing by inhibiting oxide film etching.

[0126] The silicon film can be a silicon oxide film, such as silicon, silicon oxide film, silicon nitride film, and silicon carbonitride film.

[0127] In the etching cleaning solution composition of the present invention, the alkaline compound containing hydroxyl groups may be a compound that adjusts the pH value of the etching cleaning solution composition to 8 or higher.

[0128] As an example, the alkaline compound containing hydroxyl groups may be selected from one or more of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, ammonium hydroxide, choline hydroxide, sodium hydroxide, and potassium hydroxide. As a specific example, it may be tetramethylammonium hydroxide and tetraethylammonium hydroxide, etc.

[0129] Based on the total weight of the etching cleaning solution composition, as an example, the alkaline compound containing hydroxyl groups may contain 1% to 25% by weight, as a specific example, 5% to 20% by weight, and as a preferred example, 8% to 20% by weight. In this case, the rounding phenomenon based on over-polishing can be suppressed by inhibiting the etching of the oxide film, while simultaneously improving etching and cleaning capabilities to clean polishing residues present on the oxide film and metal layer surfaces. Furthermore, the etching cleaning solution composition does not adversely affect the achievement of excellent bonding strength in the mixed bonding process, and it also solves the disadvantage of copper over-etching when the pH value is in a neutral or acidic environment.

[0130] In the etching cleaning solution composition of the present invention, the alkanolamine compound can decompose polishing residues present on the oxide film and metal layer surface.

[0131] For reference, the alkanolamine is characterized in that it is a substance commonly used as a pH adjuster in the art, but for the purposes of this invention, the pH value is different from that described above, and it has the disadvantage of causing excessive copper etching when in a neutral or acidic environment. Therefore, it is composed of a more alkaline environment. In particular, even if an excessive amount of alkanolamine is added, it is equivalent to a substance that is difficult to provide the pH value to the strongly alkaline environment of pH 12 or 14 or higher required in this invention.

[0132] For example, the alkanolamine compound may be selected from one or more of propanolamine, ethanolamine, diethanolamine, triethanolamine, 2-2-(ethylamino)ethanol, 1-amino-2-propanol, 2-(methylamino)ethanol, N,N-dimethylethanolamine, 1,3-diamino-2-propanol, 2-amino-1,3-propanediol and 2-amino-2-methyl-1-propanol. As a specific example, it may be ethanolamine.

[0133] Based on the total weight of the etching cleaning solution composition, as an example, the alkanolamine compound may contain 0.1% to 10% by weight, as a specific example, 1% to 10% by weight, and as a preferred example, 3% to 8% by weight. In this case, rounding based on over-polishing can be suppressed by inhibiting the etching of the oxide film, while simultaneously improving etching and cleaning capabilities. Furthermore, in the mixed bonding process, the etching cleaning solution composition does not adversely affect the achievement of excellent bonding strength, while effectively cleaning polishing residues present on the oxide film and metal layer surfaces.

[0134] At this point, the cleaning materials may include polishing materials and pad debris used in polishing, as well as various residues that may be generated during the process.

[0135] At this time, a variety of materials known in the art can be used as polishing materials, such as silicon dioxide and cerium dioxide.

[0136] Alternatively, for example, the oxide film can be silicon, silicon oxide film, silicon nitride film, and silicon carbonitride film, etc.

[0137] The etching cleaning solution composition may also contain surfactants.

[0138] The surfactant may be selected from one or more nonionic surfactants and anionic surfactants.

[0139] For example, the nonionic surfactant may be a copolymer comprising polyethylene glycol, polypropylene glycol, polyoxyethylene, polyalkyl oxide, polyethylene oxide, sorbitan polyoxyethylene hexaoleate, polyoxyethylene dodecyl ether, polyoxyethylene octylphenyl ether, dodecenyl succinate monodiethanolamide and alkyl polyglucoside, or it may be Dow's TERGITOL™ TMN-6, TERGITOL™ 15-S-5 and TERGITOL™ NP-40, etc.

[0140] For example, the anionic surfactant may be a copolymer comprising alkyl ether phosphate, aryl ether phosphate, ammonium dodecyl sulfate, sodium dodecylbenzene sulfonate, ammonium dodecylbenzene sulfonate, sodium polyoxyethylene alkyl aryl sulfate, sodium polyoxyethylene alkyl sulfate, disodium dodecyl polyoxyethylene ether sulfosuccinate, sodium dodecyl polyoxyethylene ether sulfate, or TERGITOL™ W-610 from Dow Chemical, H-11 from TRITON, TRITON™ DF-20, etc.

[0141] Based on the total weight of the etching cleaning solution composition, as an example, the surfactant may contain 0.001% to 3% by weight, as a specific example, 0.001% to 1% by weight, and as a preferred example, 0.001% to 0.02% by weight. In this case, it does not adversely affect the provided etching cleaning solution composition, while effectively cleaning polishing residues present on the oxide film and metal layer surface.

[0142] As an example, the pH value of the etching cleaning solution composition can be in the range of 8 to 14, specifically in the range of 9 to 14, and preferably in the range of about 12 to 14. In this case, rounding phenomenon based on over-polishing can be suppressed by inhibiting the etching of the oxide film, while simultaneously improving etching and cleaning capabilities. Furthermore, in the mixed bonding process, the etching cleaning solution composition does not adversely affect the effect of achieving excellent bonding strength, and simultaneously provides the effect of effectively cleaning polishing residues present on the oxide film and metal layer surface.

[0143] The pH value of the etching cleaning solution composition can be in the range of 8 to 14.

[0144] The fourth step can be carried out by chemical impregnation or physical washing.

[0145] The etching cleaning solution composition planarizes the metal layer contained within the hole by etching at an etching rate of less than 50 Å / min.

[0146] The etching cleaning solution composition can remove polishing residues present on the surface of the oxide layer and the metal layer.

[0147] The hybrid bonding structure planarization process can be performed continuously and / or in batches after the fourth step by performing the following steps: activating the surface with a pulse mode; pre-bonding the die and wafer; and densely bonding the bonding structure between the die and wafer through thermal expansion.

[0148] As an example, the shape of the joint is shown below. Figure 2 middle.

[0149] the following Figure 2 The following diagram illustrates a structure in which a rounding phenomenon occurs in the mixed bonded component, forming a recess without the appearance of an oxide film, when the etching cleaning solution composition of an embodiment of the present invention is used in a chemical mechanical planarization or polishing (CMP) process. Figure 1 and Figure 3 This is a diagram showing the rounding phenomenon observed due to over-polishing of the oxide film when using a slurry composition of the prior art in a CMP process.

[0150] When the prior art slurry composition (A) is used, an aqueous solution with a pH of 7.6 containing 0.5 wt% silica particles, 0.01 wt% BTA (preservative, benzotriazole), 0.005 wt% maleic acid, 0.05 wt% hydrogen peroxide, and the balance water is used. The copper polishing speed is 52 Å / min, the TEOS (tetraethyl orthosilicate) polishing speed is 213 Å / min, and the Cu / TEOS selectivity ratio reaches 1:5, resulting in protrusion of the Cu pore shape.

[0151] As another example, when the prior art slurry composition (B) is used in an aqueous solution with a pH of 7.6 containing 0.5 wt% silica particles, 0.01 wt% BTA, 0.005 wt% maleic acid, 1.0 wt% hydrogen peroxide and the balance water, the copper polishing speed is 617 Å / min, the TEOS polishing speed is 217 Å / min, and the Cu / TEOS selectivity ratio reaches 3:1, resulting in a dishing of the Cu pore shape.

[0152] As follows Figure 1 and Figure 3 As shown, when rounding is observed, it is difficult to provide complete bonding force between the joints in the hybrid bonding process, which is a necessary subsequent process.

[0153] Therefore, when using the etching cleaning solution composition of the present invention, it is possible to produce uniform dishing of the metal layers for mixing and bonding.

[0154] The selective etching content of the metal layer can be adjusted in angstrom units by adjusting the composition content or dilution ratio and process time.

[0155] The etching cleaning solution composition can be applied using a pad, a brush, or both. As an example, part (a) of Figure 5 below shows the use of a pad, part (b) shows the use of a brush, and part (c) shows the use of a pad followed by a brush.

[0156] After the etching cleaning, a DW cleaning step may also be included. As an example, part (d) of Figure 5 below is a diagram of applying the etching cleaning solution composition to a pad and then performing DW cleaning with a brush.

[0157] As an example, the metal thermal expansion space can be a metal layer with a depth of less than 100 Å from the top, preferably less than 50 Å, and the result can provide a flat rectangular structure.

[0158] Most preferably, the lateral width of the metal thermal expansion space is the width of the hole 102. For example, it can be less than 5 μm, preferably 0.5 μm to 5 μm, but this can vary depending on the process.

[0159] The substrate is fixed to the head and rotates together with the chuck. The platen at the lower end of the CMP rotates in the same direction as the aforementioned rotation. For example, a rotational speed of 40 RPM to 90 RPM effectively removes the barrier layer. For example, a rotational speed of 40 RPM to 90 RPM effectively creates a space for metal thermal expansion. The removal profile is related to the rotational speed. Higher rotational speeds induce higher substrate edge removal speeds, and lower rotational speeds induce lower substrate edge removal speeds.

[0160] The etching cleaning solution composition supply nozzle is movable during the process. The etching cleaning speed is affected by the nozzle scanning speed and the scanning area. The optimal scanning speed can be below 100 mm / s, specifically, it can be from 40 mm / s to 100 mm / s.

[0161] The planarization apparatus for hybrid bonding structures of the present invention includes: an Equipment Front End Module (EFEM), a buffer station, a process robot, two or more stacked CMP modules 1001, a measurement module, a pad module 1007, a brush module 1009, an etching cleaning module 1003, and a DW cleaning module 1005. The measurement module, pad module 1007, and brush module 1009 can be stacked on the etching cleaning module 1003 and / or the DW cleaning module 1005, or operate simultaneously with the etching cleaning module 1003 and / or the DW cleaning module 1005.

[0162] The device also includes an electrical module, a gas module, and a pipeline module.

[0163] To remove the metal layer on the non-recessed areas of the substrate, CMP module 1001 is used to perform a chemical mechanical polishing process on the substrate. A second or more of the two or more CMP modules 1001 can be used to planarize the step difference between the metal layer and oxide film layer formed within the hole by using a slurry with a polishing speed selection ratio of oxide layer to metal layer adjusted to 1:1.

[0164] The etching cleaning module can be used to remove the barrier layer formed on the bottom and sidewalls of the hole while simultaneously forming a flat space for metal thermal expansion by filling the recessed area of ​​the substrate with an etching cleaning liquid composition.

[0165] The planarization device for the hybrid bonding structure may also include a DW cleaning module.

[0166] The DW cleaning module can be operated after the etching cleaning module.

[0167] The etching cleaning module can be a pad module or a brush module.

[0168] The DW cleaning module can be a brush module.

[0169] According to one implementation of the present invention, as follows: Figure 4a and Figure 5a As shown, the planarization device for the hybrid bonding structure can be composed of a first CMP module, a second CMP module, and an etching cleaning pad module.

[0170] The first CMP module, the second CMP module, and the etching cleaning pad module can be composed of continuous or batch processes, and from the perspective of process efficiency, continuous processing is preferred. Figure 5a This corresponds to continuous actions.

[0171] The first CMP module 1001 performs operations to remove the metal layer (Cu) and to make the step difference between the metal layer and the oxide film layer (Cu / Ox) consistent.

[0172] The second or more of the two or more CMP modules 1001 can simultaneously perform the following for 60 seconds or less using slurry supplied through a slurry supply nozzle at a selection ratio of 1:1. Figure 5a The steps (b) and (c) are shown in the diagram. At this time, the working time can be in the range of 20 seconds to 100 seconds.

[0173] As an example, when the slurry (C) with a selectivity ratio of 1:1 was used, and an aqueous solution with a pH of 7.6 containing 0.5 wt% silica particles, 0.01 wt% BTA, 0.008 wt% maleic acid, 0.35 wt% hydrogen peroxide and the balance water was used, the copper polishing speed was 208 Å / min, the TEOS polishing speed was 217 Å / min, the Cu / TEOS selectivity ratio reached approximately 1:1, the results confirmed that the Cu pore shape had a consistent step, and the actual measured roughness was confirmed to be approximately 1.4 Å.

[0174] Next, the etching cleaning module 1003 may overlap with the pad module 1007, and the etching cleaning solution composition supplied from the etching cleaning solution supply nozzle shall be used for the following 60 seconds. Figure 5a Step (d) is shown in the diagram. At this point, the etching cleaning solution composition uses the aforementioned components, and the working time can be in the range of 20 seconds to 100 seconds.

[0175] The results show that, according to Figure 5a The flowchart shown in the figure illustrates that the substrate, after undergoing the planarization process using the planarization apparatus, achieves a substrate with... Figure 2The structure of the planarized metal thermal expansion space is shown. As an example, the lateral width of the metal thermal expansion space within the hole is 1.5 μm, and the longitudinal depth is 50 Å from the top edge of the oxide layer, but it is not limited to this.

[0176] According to another implementation of the present invention, as follows: Figure 4b and Figure 5b As shown, the planarization device for the hybrid bonding structure can be composed of a first CMP module, a second CMP module, a third CMP module, and an etching cleaning brush module.

[0177] The first CMP module, the second CMP module, the third CMP module, and the etching cleaning brush module can be composed of continuous or batch processes, and from the perspective of process efficiency, continuous processing is preferred. Figure 5b This corresponds to continuous actions.

[0178] The first CMP module 1001 performs operations to remove the metal layer (Cu) and to make the step difference between the metal layer and the oxide film layer (Cu / Ox) consistent.

[0179] The second and subsequent modules of the two or more CMP modules 1001 (corresponding to the second and third CMP modules in Figure 5) can sequentially perform the following for 60 seconds using a slurry supplied through a slurry supply nozzle at a selection ratio of 1:1. Figure 5b The steps (b) and (c) are shown in the diagram. At this time, the working time can be in the range of 20 seconds to 100 seconds.

[0180] Next, the etching cleaning module 1003 may overlap with the brush module 1009, and perform the following for 60 seconds using an etching cleaning solution composition supplied from the etching cleaning solution supply nozzle. Figure 5b Step (d) is shown in the diagram. At this point, the etching cleaning solution composition uses the aforementioned components, and the working time can be in the range of 20 seconds to 100 seconds.

[0181] The results show that, according to Figure 5b The flowchart shown in the figure illustrates that the substrate, after undergoing the planarization process using the planarization apparatus, achieves a substrate with... Figure 2 The structure of the planarized metal thermal expansion space is shown. Specifically, the lateral width of the metal thermal expansion space within the hole is 1.5 μm, and the longitudinal depth is 50 Å from the top edge of the virtually drawn oxide layer.

[0182] According to another implementation of the present invention, as follows: Figure 4c and Figure 5c As shown, the planarization device for the hybrid bonding structure can be composed of a first CMP module, a second CMP module, an etching cleaning pad module, and an etching cleaning brush module.

[0183] The first CMP module, the second CMP module, the etching cleaning pad module, and the etching cleaning brush module can be composed of continuous or batch processes, and from the perspective of process efficiency, the continuous process is preferred. Figure 5c This corresponds to continuous actions.

[0184] The first CMP module 1001 performs operations to remove the metal layer (Cu) and to make the step difference between the metal layer and the oxide film layer (Cu / Ox) consistent.

[0185] The second CMP module 1001 can simultaneously perform the following for 60 seconds using slurry supplied through a slurry supply nozzle at a selectable ratio of 1:1. Figure 5c The steps (b) and (c) are shown in the diagram. At this time, the working time can be in the range of 20 seconds to 100 seconds.

[0186] Next, the etching cleaning module 1003 may overlap with the pad module 1007 and the brush module 1009, and the following process is performed sequentially for 60 seconds using an etching cleaning solution composition supplied from the etching cleaning solution supply nozzle. Figure 5c Step (d) is shown in the diagram. At this point, the etching cleaning solution composition uses the aforementioned components, and the working time can be in the range of 20 seconds to 100 seconds.

[0187] The results show that, according to Figure 5c The flowchart shown in the figure illustrates that the substrate, after undergoing the planarization process using the planarization apparatus, achieves a substrate with... Figure 2 The structure of the planarized metal thermal expansion space is shown. Specifically, the lateral width of the metal thermal expansion space within the hole is 1.5 μm, and the longitudinal depth is 50 Å from the top edge of the virtually drawn oxide layer.

[0188] According to one implementation of the present invention, as follows: Figure 4d and Figure 5d As shown, the planarization device for the hybrid bonding structure can be composed of a first CMP module, a second CMP module, an etching cleaning pad module, and a DW cleaning brush module.

[0189] The first CMP module, the second CMP module, the etching cleaning pad module, and the DW cleaning brush module can be composed of continuous or batch processes, and from the perspective of process efficiency, continuous processing is preferred. Figure 5d This corresponds to continuous actions.

[0190] The first CMP module 1001 performs operations to remove the metal layer (Cu) and to make the step difference between the metal layer and the oxide film layer (Cu / Ox) consistent.

[0191] The second CMP module 1001 can simultaneously perform the following for 60 seconds using slurry supplied through a slurry supply nozzle at a selectable ratio of 1:1. Figure 5d The steps (b) and (c) are shown in the diagram. At this time, the working time can be in the range of 20 seconds to 100 seconds.

[0192] Next, the etching cleaning module 1003 may overlap with the pad module 1007, and the following process is performed sequentially for 60 seconds using an etching cleaning solution composition supplied from the etching cleaning solution supply nozzle. Figure 5d Step (d) is shown in the diagram. At this point, the etching cleaning solution composition uses the aforementioned components, and the working time can be in the range of 20 seconds to 100 seconds.

[0193] Then, the DW cleaning module 1005 can overlap with the brush module 1009 and sequentially perform the following 60-second cleaning cycles using deionized water supplied from the DW (deionized water) supply nozzle. Figure 5d The step (e) shown in the figure. At this time, the working time can be from 10 seconds to 60 seconds respectively.

[0194] The results show that, according to Figure 5d The flowchart shown in the figure illustrates that the substrate, after undergoing the planarization process using the planarization apparatus, achieves a substrate with... Figure 2 The structure of the planarized metal thermal expansion space is shown. Specifically, the lateral width of the metal thermal expansion space within the hole is 1.5 μm, and the longitudinal depth is 50 Å from the top edge of the virtually drawn oxide layer.

[0195] The planarization device for the hybrid bonding structure can be connected to a pulse mode, a pre-bonding device, and a thermal expansion device to perform post-processing steps for hybrid bonding.

[0196] The following is a planarization device shown in Figure 5 ( Figure 5a , Figure 5b , Figure 5c , Figure 5d The left side of the diagram illustrates the substrate transfer sequence.

[0197] An EFEM robot picks up an unprocessed substrate from the loading section and transfers it to a buffer station. A process robot picks up the substrate from the buffer station and transfers it to a measurement module for determining the thickness of the metal layers. After the measurement module measures the thickness of the metal layers, the process robot picks up the substrate from the measurement module and transfers it to one of the CMP modules 1001. In the CMP module 1001, a CMP process is applied to the substrate to remove all metal layers on non-recessed areas and a portion of the upper metal layers within the holes. After completing the CMP process, the process robot picks up the substrate from the CMP module 1001 and transfers it to a second CMP module 1001. The second CMP module 1001 receives slurry supplied from the slurry supply nozzle while the CMP process is applied to the substrate to remove barrier layers and oxide layers on non-recessed areas and planarize the metal layers within the holes (the above is the same as portions (a), (b), (c), and (d) of Figure 5 below).

[0198] Next, as shown in part (a) of Figure 5 below, after completing the second CMP process, the process robot picks up the substrate from the second CMP module 1001 and transfers it to the etching cleaning pad module 1007. The etching cleaning pad module 1007 receives the etching cleaning solution composition supplied from the etching cleaning solution composition supply nozzle while the etching cleaning process is applied to the substrate to remove the sidewalls and lower barrier layers of the holes, while forming a metal thermal expansion space at the upper end of the metal layer within the holes.

[0199] Then, the process robot picks up the substrate from the etching cleaning pad module 1007 and transfers the substrate to the buffer station. Finally, the EFEM robot picks up the substrate from the buffer station and transfers it again to the substrate loading section.

[0200] According to another implementation example, as shown in part (b) of Figure 5 below, after completing the second CMP process, the process robot picks up the substrate from the second CMP module 1001 and transfers it to the third CMP module 1001. The third CMP module 1001 receives slurry supplied from the slurry supply nozzle while the CMP process is applied to the substrate to remove the barrier layer and oxide layer on the non-recessed areas and further planarize the metal layer in the holes.

[0201] After completing the third CMP process, the process robot picks up the substrate from the second CMP module 1001 and transfers it to the etching cleaning brush module 1009. The etching cleaning brush module 1009 receives the etching cleaning solution composition supplied from the etching cleaning solution composition supply nozzle while the etching cleaning process is applied to the substrate to remove the sidewalls and lower barrier layers of the holes, while forming a metal thermal expansion space at the upper end of the metal layer within the holes.

[0202] Then, the process robot picks up the substrate from the etching and cleaning brush module 1009 and transfers the substrate to the buffer station. Finally, the EFEM robot picks up the substrate from the buffer station and transfers it again to the substrate loading section.

[0203] According to another implementation example, as shown in part (c) of Figure 5 below, after completing the second CMP process, the process robot picks up the substrate from the second CMP module 1001 and transfers it to the etching cleaning pad module 1007. The etching cleaning pad module 1007 receives the etching cleaning solution composition supplied from the etching cleaning solution composition supply nozzle while the etching cleaning process is applied to the substrate to remove the sidewalls and lower barrier layers of the holes, while forming a metal thermal expansion space at the upper end of the metal layer within the holes.

[0204] Next, the process robot picks up the substrate from the etching cleaning pad module 1007 and transfers it to the etching cleaning brush module 1009. The etching cleaning brush module 1009 receives the etching cleaning solution composition supplied from the etching cleaning solution composition supply nozzle while the etching cleaning process is applied to the substrate to remove the sidewalls and lower barrier layer of the hole, while forming a metal thermal expansion space at the upper end of the metal layer within the hole.

[0205] Then, the process robot picks up the substrate from the etching and cleaning brush module 1009 and transfers the substrate to the buffer station. Finally, the EFEM robot picks up the substrate from the buffer station and transfers it again to the substrate loading section.

[0206] According to another implementation example, as shown in part (d) of Figure 5 below, after completing the second CMP process, the process robot picks up the substrate from the second CMP module 1001 and transfers it to the etching cleaning pad module 1007. The etching cleaning pad module 1007 receives the etching cleaning solution composition supplied from the etching cleaning solution composition supply nozzle while the etching cleaning process is applied to the substrate to remove the sidewalls and lower barrier layers of the holes, while forming a metal thermal expansion space at the upper end of the metal layer within the holes.

[0207] Next, the process robot picks up the substrate from the etching cleaning pad module 1007 and transfers it to the DW cleaning module 1005. The DW cleaning module 1005 cleans the substrate by filling the thermal expansion space of the metal layer within the hole with DW, thereby helping to form a more flattened space.

[0208] Then, the process robot picks up the substrate from the DW cleaning module 1005 and transfers it to the buffer station. Finally, the EFEM robot picks up the substrate from the buffer station and transfers it again to the substrate loading section.

[0209] In addition to the aforementioned substrate transfer sequence, other substrate transfer sequences can be performed using a device according to the requirements of other processes.

[0210] To achieve high-speed and uniform removal, preferably, the removal or polishing of the substrate material is not composed of purely physical or purely chemical actions, but rather through a synergistic combination of both.

[0211] Therefore, chemical impregnation and physical washing are methods commonly used in this technical field, and any method can be used. Since these are well-known in this technical field, detailed descriptions will be omitted.

[0212] In particular, as can be confirmed from the following embodiments, the etching effect obtained when using the etching cleaning liquid composition to which the present invention is applicable may include: providing an etching rate of 50 Å / min or less for the metal layer included in the semiconductor device or display device; forming a recess on the metal layer with an appropriate thickness of 20 Å or less; and forming a surface roughness of 5 Å or less for the silicon film, etc.

[0213] In this case, the cleaning effect may include: removing more than 99% or almost all of the polishing residues present on the surface of oxide films and metal layers in semiconductor devices or display devices.

[0214] Semiconductor devices refer to semiconductor memory devices such as DRAM, NAND, especially high bandwidth memory (HBM), graphics double data rate (GDDR), system semiconductor devices such as central processing unit (CPU), application processor (AP), or their heterogeneous semiconductor devices, but are not limited to these.

[0215] In addition, display devices refer to image sensors such as CMOS image sensors (CIS), but are not limited to these.

[0216] Therefore, when using the planarization method and apparatus for the hybrid bonding structure of the present invention, when forming a depression between the joints required for hybrid bonding, it can not only suppress the rounding phenomenon caused by excessive polishing of the oxide film and remove polishing residues on the surface of the oxide film and the metal layer, but also reduce process costs while demonstrating the bonding force improvement effect of the hybrid bonding process.

[0217] Furthermore, with existing CMP slurries, it is difficult to adjust the selectivity ratio of the polishing speed of the oxide film to that of Cu, thus making it impossible to control the appropriate dish-shaped recess of the copper via. This is because, in the selectivity ratio of oxide film to copper, if the polishing speed of the oxide film is too fast compared to that of the copper, the required dish-shaped recess of the copper via electrode cannot be formed, and therefore the bonding process cannot be performed. Conversely, if the polishing speed of the copper is too fast, the deep dish-shaped recess of the copper via electrode will prevent the copper via electrode from being bonded during the bonding process. This problem can be solved by using the planarization method and apparatus for the hybrid bonding structure of the present invention.

[0218] Preferred embodiments are presented below to aid in understanding the present invention. However, these embodiments are merely illustrative of the present invention. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope and technical concept of the present invention, and such changes and modifications are also included in the appended claims.

[0219] Etching cleaning solution compositions: Examples 1 to 10, Comparative Examples 1 to 9 The etching cleaning solution compositions used in Examples 1 to 10 and Comparative Examples 1 to 9 were prepared respectively.

[0220] Specifically, etching cleaning solutions with the compositions shown in Tables 1, 2, 4, 5, and 6 below were prepared prior to mixed bonding. After preparation, the solutions were diluted in deionized water at a ratio of 100:1. The temperature of each cleaning solution was set to 25°C.

[0221] Each compound was prepared in weight percent and contained residual water. In particular, except that the pH of tetraethylammonium hydroxide (TEAH), used as a pH adjuster, was 6 in Comparative Example 7 and 11.5 in Comparative Example 8, all other formulations were added in different weight percent to adjust the pH of all other formulations to the same 13.

[0222] Using the etching cleaning solution composition, by means of Figures 4a to 4d , Figures 5a to 5d The silicon oxide film (SiO) and copper electrode shown are used as objects to evaluate whether the 10nm copper disc-shaped depression and the rounding phenomenon of the silicon oxide film (SiO) can be suppressed.

[0223] At this point, as a performance evaluation, the etching rate of copper, the etching rate of the silicon oxide film, the roughness change of the silicon oxide film (before and after), the cleaning power of the silicon dioxide polishing material, and the cleaning power of organic residues were compared using immersion and brushing methods. The measurement methods are as follows: <Etching speed of copper> (Thickness before copper evaluation - Thickness after copper evaluation) / Evaluation time [Å / minute] The copper etching rate was evaluated by measuring the copper thickness using a surface resistivity meter (AIT, CMT-SR5000).

[0224] (1) After cutting the copper into 2cm×2cm pieces, pre-treatment is performed to remove the copper oxide film.

[0225] (2) The thickness before evaluation was measured by a surface resistivity meter.

[0226] (3) After the cleaning solution is in contact with the copper for a certain period of time by immersion or brushing, rinse with pure water and dry the surface with nitrogen.

[0227] (4) The thickness of the evaluated copper was measured by a surface resistivity meter.

[0228] <Etching rate of silicon oxide film> (Thickness of silicon oxide film before evaluation) - (Thickness of silicon oxide film after evaluation)) / Evaluation time [Å / min].

[0229] The thickness of the silicon oxide film was measured and evaluated using an ellipsometry (ULAM, M-2000) to assess the etching rate of the silicon oxide film.

[0230] (1) After cutting the silicon oxide film into 2cm×2cm pieces, pretreatment is performed to remove the natural oxide film.

[0231] (2) The thickness before evaluation was measured by ellipsometer.

[0232] (3) After the cleaning solution is in contact with the silicon oxide film for a certain period of time by immersion or brushing, rinse with pure water and dry the surface with nitrogen.

[0233] (4) The thickness of the evaluated silicon oxide film was measured by a surface resistivity meter.

[0234] <Roughness variation of silicon oxide film> (Roughness of silicon oxide film before evaluation) - (Roughness of silicon oxide film after evaluation).

[0235] <-0.01nm: Roughness increases >0.01nm: Roughness reduction -0.01~+0.01nm: No change The roughness variation of the silicon oxide film was analyzed using an atomic force microscope (Park Systems, XE15).

[0236] (1) After cutting the silicon oxide film into 2cm×2cm pieces, pretreatment is performed to remove the natural oxide film.

[0237] (2) The roughness before evaluation was measured by atomic force microscopy.

[0238] (3) After the cleaning solution is in contact with the silicon oxide film for a certain period of time by immersion or brushing, rinse with pure water and dry the surface with nitrogen.

[0239] (4) The roughness of the evaluated silicon oxide film was measured by atomic force microscopy.

[0240] Cleaning power of silica polishing materials for copper (Width of silica polishing material when contaminated) - (Width of silica polishing material after evaluation) / (Width of silica polishing material when contaminated) × 100 (%); Particle Removal Efficiency (PRE).

[0241] O: Above 99.5%, △: 99.0%~99.5%, X: Below 99.0%.

[0242] The silica polishing material present on the copper surface was analyzed using a scanning electron microscope (Hitachi, S4800).

[0243] (1) Cut the copper into 2cm×2cm pieces and then pre-treat it.

[0244] (2) After impregnating the polishing material containing silica polishing material and simulating silica contamination, the width of the silica polishing material relative to the analysis width is calculated by using a scanning electron microscope and a program.

[0245] (3) After the cleaning solution is in contact with the copper film for a certain period of time by immersion or brushing, rinse with pure water and dry the surface with nitrogen.

[0246] (4) After evaluation, calculate the area of ​​residual silicon dioxide on the copper surface.

[0247] (5) Calculate PRE.

[0248] Cleaning power of silica polishing materials in silica films (Width of silica polishing material when contaminated) - (Width of silica polishing material after evaluation) / (Width of silica polishing material when contaminated) × 100 (%); Particle Removal Efficiency (PRE).

[0249] O: Above 99.0%, △: 97.0%~99.0%, X: Below 97.0%.

[0250] The silica polishing material present on the surface of the silica film was analyzed using a scanning electron microscope (Hitachi, S4800).

[0251] (1) After cutting the silicon oxide film into 2cm×2cm pieces, pretreatment is performed.

[0252] (2) After impregnating the polishing material containing silica polishing material and simulating silica contamination, the width of the silica polishing material relative to the analysis width is calculated by using a scanning electron microscope and a program.

[0253] (3) After the cleaning solution is in contact with the silicon oxide film for a certain period of time by immersion or brushing, rinse with pure water and dry the surface with nitrogen.

[0254] (4) After evaluation, calculate the area of ​​residual silicon dioxide on the surface of the silicon oxide film.

[0255] (5) Calculate PRE.

[0256] <Cleansing power for organic residues> (Number of organic particles remaining after cleaning organic matter).

[0257] O: 0EA, △: below 50EA, X: above 50EA.

[0258] Organic particles present on the surfaces of copper and silicon oxide films were analyzed using a scanning electron microscope (Hyrox, KH-8700).

[0259] (1) Cut the copper or silicon oxide film into 2cm×2cm pieces and then pre-treat it.

[0260] (2) Add organic powder to the spray in the IPA and then spray it onto the film.

[0261] (3) After the cleaning solution is in contact with the copper or silicon oxide film for a certain period of time by immersion or brushing, rinse with pure water and dry the surface with nitrogen.

[0262] (4) After evaluation, count the number of organic particles remaining on the surface of the copper or silicon oxide film.

[0263] Confirmation of copper oxide film formation After evaluation, to confirm whether an oxide film had formed on the copper, the elemental intensities of copper (Cu) and oxygen (O) were confirmed using an X-ray fluorescence spectrometer (XRF, Rigaku Corporation, ZSX Primus 400).

[0264] (1) After cutting the copper wafer into 2cm×2cm sizes, perform pretreatment.

[0265] (2) Before evaluation, the intensity of copper and oxygen was confirmed using energy dispersive X-ray fluorescence spectrometry.

[0266] (3) Soak in cleaning solution for 1 hour.

[0267] (4) After evaluation, confirm the strength of copper and oxygen.

[0268] Table 1

[0269] Table 1 confirms that the etching rate of the metal layer (copper) can be adjusted according to the type of etching material. Furthermore, it confirms that the adjustment of the copper etching rate is not limited to the type of etching material, but can also be adjusted based on process conditions (time, temperature, and cleaning method), the content of the etching material, and the dilution ratio of deionized water.

[0270] As a specific example, in the additional embodiment 1, if the immersion evaluation is performed for 30 seconds, a copper depression with a thickness of 15 angstroms can be formed. However, the brushing evaluation results show that the copper etching rate is lower than that of the immersion evaluation results. This is because not enough time was given during the copper etching process.

[0271] Furthermore, depending on the characteristics of the components (such as polarity and hydrophilicity), etching may not occur during the brushing process. Therefore, if copper indentations are sufficiently created by CMP, further copper etching can be prevented by using the etching cleaning solution composition of Additional Example 3.

[0272] Table 2

[0273] The intensity of copper (Cu) and oxygen (O) elements in pure copper wafers and Examples 1, 5 and 6 was measured under vacuum conditions.

[0274] Table 3

[0275] As shown in Table 2, the oxygen intensity of Examples 1, 5 and 6 decreased after evaluation. As shown in Table 3, it can be confirmed that no copper oxide film was formed.

[0276] Table 4

[0277] As shown in Table 4, the effectiveness of the silicon oxide film etchant was confirmed in the brushing evaluation.

[0278] Table 5

[0279] As shown in Table 5, surfactants may also be included. In this case, it was confirmed that the roughness of the silica film can be reduced, but a decrease in cleaning power is achieved.

[0280] Table 6

[0281] As shown in Table 6, in Example 1, excellent performance was confirmed in terms of cleaning power of silica polishing materials, cleaning power of organic matter, etching rate of silica film, and roughness of silica film. In Comparative Examples 1 to 5, the effectiveness of the organic solvent MEA in cleaning organic matter was confirmed. However, according to Comparative Examples 1 to 5, a decrease in cleaning power was confirmed when the composition was not mixed.

[0282] Furthermore, in Comparative Example 6, which used MEA alone, it was confirmed that the cleaning effect on the copper film surface was poor. In Comparative Example 7, which used ammonium acetate instead of TEAH, it was confirmed that the cleaning results of the copper film and silicon oxide film were poor. In Comparative Example 8, which did not use TEAH and adjusted the pH to 11.5 with alkanolamine, it was confirmed that the cleaning of the copper film and silicon oxide film was poor overall. In Comparative Example 9, which used hydrogen peroxide as an etching agent (citric acid, etc.), it was confirmed that the copper was not etched and the cleaning effect on the silicon oxide film was very poor.

[0283] Therefore, when the etching cleaning liquid composition of the present invention is used in the existing cleaning steps of the planarization method and apparatus for hybrid bonding structures, when a depression is formed between the joints required for hybrid bonding, the rounding phenomenon caused by excessive polishing of the oxide film can be suppressed, and polishing residues present on the surface of the oxide film and the metal layer can be removed at the same time. Furthermore, the process cost can be reduced while exhibiting the effect of improved bonding force in the hybrid bonding process.

[0284] Furthermore, with existing CMP slurries, it is difficult to adjust the selectivity ratio of the polishing speed of the oxide film to that of Cu, thus making it impossible to control the appropriate dish-shaped recess of the copper via. This is because, in the selectivity ratio of oxide film to copper, if the polishing speed of the oxide film is too fast compared to that of the copper, the required dish-shaped recess of the copper via electrode cannot be formed, and therefore the bonding process cannot be performed. Conversely, if the polishing speed of the copper is too fast, the deep dish-shaped recess of the copper via electrode will prevent bonding of the copper via electrode during the bonding process. This problem can be solved by using the etching cleaning solution composition of the present invention in the existing cleaning steps of the planarization method and apparatus for hybrid bonding structures.

Claims

1. A method for planarizing hybrid bonding structures, characterized in that, The hybrid bonding structure includes: substrate, Holes are formed in the recessed areas of the substrate. Oxide layers are formed in the recessed and non-recessed regions of the substrate, respectively. A barrier layer is formed on the bottom and sidewalls of the pore and on the oxide layer, and A metal layer is formed inside the hole and on the barrier layer; The planarization method for the hybrid bonding structure includes: The first step is to remove the metal layer that has formed on the non-recessed areas. The second step involves removing the metal layer residue, oxide layer, and barrier layer formed on the oxide layer from the non-recessed area. The third step involves planarizing the step difference between the metal layer and the oxide film layer formed within the hole, and... The fourth step is to remove the barrier layer formed on the bottom and sidewalls of the hole, while simultaneously forming a metal thermal expansion space in a flat form.

2. The planarization method for hybrid bonding structures according to claim 1, characterized in that, The metal layer is made of copper. The barrier layer is made of one or more materials selected from Ti, TiN, Ta, and TaN. The oxide layer is made of one or more materials selected from Si, SiO2, and SiCN.

3. The planarization method for hybrid bonding structures according to claim 1, characterized in that, The metal layers removed in the first step are all the metal layers deposited on the non-recessed areas and some of the metal layers formed inside the holes.

4. The planarization method for hybrid bonding structures according to claim 1, characterized in that, The first, second, and third steps are performed through a chemical mechanical polishing process.

5. The planarization method for hybrid bonding structures according to claim 1, characterized in that, The second and third steps are performed separately or simultaneously using a slurry with a polishing speed selection ratio of 1:1 between the oxide layer and the metal layer.

6. The planarization method for hybrid bonding structures according to claim 5, characterized in that, The slurry comprises: 0.05wt% to 5wt% silica particles, 0.001 wt% to 1 wt% of an azole corrosion inhibitor containing one or more N groups, 0.001 wt% to 0.5 wt% of amino acid complexing agents, 0.05wt% to 1wt% of oxidant, and The remaining water.

7. The planarization method for hybrid bonding structures according to claim 1, characterized in that, The fourth step is performed by filling the recessed areas of the substrate with an etching cleaning solution composition.

8. The planarization method for hybrid bonding structures according to claim 1, characterized in that, After filling with the etching cleaning solution composition in the fourth step, the method further includes step (e) of filling the recessed areas of the substrate with deionized water.

9. The planarization method for hybrid bonding structures according to claim 8, characterized in that, The etching cleaning solution composition and deionized water are filled using one or more pads and brushes selected independently from each other.

10. The planarization method for hybrid bonding structures according to claim 7, characterized in that, The etching cleaning solution composition is an alkaline solution containing etching substances, metal corrosion inhibitors, silicon film anti-etching agents, hydroxyl-containing alkaline compounds, and alkaline amine-containing compounds.

11. The planarization method for hybrid bonding structures according to claim 10, characterized in that, Based on the total weight of the etching cleaning solution composition, the etching substance comprises 0.1% to 10% by weight of one or more selected from asparagine, ammonium citrate, glycine, arginine, histidine, lysine, alanine, citric acid, aspartic acid, and glutamic acid.

12. The planarization method for hybrid bonding structures according to claim 7, characterized in that, The etching cleaning solution composition planarizes the metal layer contained within the hole by etching at an etching rate of less than 50 angstroms per minute.

13. A planarization device for a hybrid bonding structure, characterized in that, The hybrid bonding structure includes: substrate, Holes are formed in the recessed areas of the substrate. Oxide layers are formed in the recessed and non-recessed regions of the substrate, respectively. A barrier layer is formed on the bottom and sidewalls of the pore and on the oxide layer, and A metal layer is formed inside the hole and on the barrier layer; The planarization device for the hybrid bonding structure includes at least two CMP modules and an etching cleaning module.

14. The planarization apparatus for hybrid bonding structures according to claim 13, characterized in that, All modules starting from the second of the two or more CMP modules use a slurry with a polishing speed selection ratio of oxide layer to metal layer adjusted to 1:1 to flatten the step between the metal layer and oxide film layer formed in the hole.

15. The planarization apparatus for hybrid bonding structures according to claim 13, characterized in that, The etching cleaning module removes the barrier layer formed on the bottom and sidewalls of the hole by filling the recessed area of ​​the substrate with an etching cleaning liquid composition, while simultaneously forming a metal thermal expansion space in a flat form.

16. The planarization apparatus for hybrid bonding structures according to claim 13, characterized in that, The etching cleaning module is either a pad module or a brush module.

17. The planarization apparatus for hybrid bonding structures according to claim 13, characterized in that, The planarization device for the hybrid bonding structure also includes a deionized water cleaning module.

18. The planarization apparatus for hybrid bonding structures according to claim 13, characterized in that, The planarization device for the hybrid bonding structure consists of a first CMP module, a second CMP module, and an etching cleaning pad module.

19. The planarization apparatus for hybrid bonding structures according to claim 13, characterized in that, The planarization device for the hybrid bonding structure consists of a first CMP module, a second CMP module, a third CMP module, and an etching cleaning brush module.

20. The planarization apparatus for hybrid bonding structures according to claim 13, characterized in that, The planarization device for the hybrid bonding structure consists of a first CMP module, a second CMP module, an etching cleaning pad module, and an etching cleaning brush module.

21. The planarization apparatus for hybrid bonding structures according to claim 13, characterized in that, The planarization device for the hybrid bonding structure consists of a first CMP module, a second CMP module, an etching cleaning pad module, and a deionized water cleaning brush module.

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