Chemical solution, method for treating for material to be treated, and method for producing semiconductor device

Abstract

The present invention provides: a chemical solution that can selectively remove a SiGe-containing substance having a high Ge concentration more than a SiGe-containing substance having a low Ge concentration from a material to be treated which contains two SiGe-containing substances having differing Ge concentrations; a method for treating a material to be treated with the chemical solution; and a method for producing a semiconductor device. A chemical solution according to the present invention is used with respect to a material to be treated that contains two silicon-germanium-containing substances having differing germanium concentrations, said chemical solution comprising water, hydrogen chloride, and hydrogen peroxide, wherein the mass ratio of the hydrogen peroxide content to the hydrogen chloride content is not less than 0.20, and the mass ratio of the water content to the hydrogen chloride content is 130-560.

Description

Chemical solution, method for treating object to be treated, and method for manufacturing semiconductor device

[0001] The present invention relates to a chemical solution, a method for treating an object to be treated, and a method for manufacturing a semiconductor device.

[0002] As semiconductor devices become increasingly miniaturized, there is an increasing demand for highly efficient and accurate chemical etching and cleaning processes during the semiconductor device manufacturing process. In particular, when multiple materials exist on a substrate, it is desirable to be able to selectively remove a specific material.

[0003] For example, Patent Document 1 discloses a composition for selectively etching silicon-germanium-containing materials, which contains an oxidizing agent, a fluoride ion source, and the like.

[0004] International Publication No. 2023 / 1610585

[0005] Depending on the application, it may be necessary to selectively remove at least a portion of silicon-germanium (SiGe)-containing materials with a high germanium (Ge) concentration from a workpiece having a plurality of SiGe-containing materials with different compositions. The present inventors have studied the composition specifically disclosed in Patent Document 1 and found that the selective removal of SiGe-containing materials according to the Ge concentration is insufficient and that improvement is necessary.

[0006] Therefore, an object of the present invention is to provide a chemical solution that can selectively remove SiGe-containing materials with a high Ge concentration from SiGe-containing materials with a low Ge concentration from a workpiece having two types of SiGe-containing materials with different Ge concentrations. Another object of the present invention is to provide a method for treating a workpiece using the chemical solution and a method for manufacturing a semiconductor device.

[0007] As a result of extensive research into solving the above problems, the present inventors have found that the problems can be solved by the following configuration.

[0008] (1) A chemical solution used for treating an object having two silicon-germanium-containing materials with different germanium concentrations, the chemical solution containing water, hydrogen chloride, and hydrogen peroxide, wherein the mass ratio of the hydrogen peroxide content to the hydrogen chloride content is 0.20 or more, and the mass ratio of the water content to the hydrogen chloride content is 130 to 560. (2) The chemical solution according to (1), which has a pH of 0.5 to 1.6. (3) The chemical solution according to (1) or (2), which further contains ammonium ions. (4) The chemical solution according to any one of (1) to (3), which is used for treating an object having two silicon-germanium-containing materials with different germanium concentrations and a silicon-containing material other than the silicon-germanium-containing materials. (5) A method for treating an object, comprising the step of contacting an object having two silicon-germanium-containing materials with different germanium concentrations with the chemical solution according to any one of (1) to (4). (6) The method for treating an object according to (5), wherein the temperature of the chemical solution is 60° C. or higher. (7) A method for manufacturing a semiconductor device, including the method for treating an object according to (5).

[0009] According to the present invention, a chemical solution can be provided that can selectively remove SiGe-containing materials with a high Ge concentration from SiGe-containing materials with a low Ge concentration from a workpiece having two types of SiGe-containing materials with different Ge concentrations. Furthermore, according to the present invention, a method for treating a workpiece using the chemical solution and a method for manufacturing a semiconductor device can be provided.

[0010] 1 is a cross-sectional view showing an embodiment of an object to be treated, and FIG. 2 is an example of a cross-sectional view showing an object to be treated after being treated by a method for treating an object to be treated of the present invention.

[0011] The present invention will be described in detail below. The following description of the components may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0012] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits. Furthermore, in this specification, when two or more types of a certain component are present, the "content" of that component means the total content of those two or more components. In this specification, in a numerical range described in stages, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in a numerical range described in this specification, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the Examples. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment.

[0013] In this specification, the term "SiGe-containing material" refers to a material containing Si and Ge elements, and is preferably a material substantially composed of only Si and Ge elements. The term "substantially" means that the total content of Si and Ge elements is 90 atomic % or more relative to the total atoms of the material. A material substantially composed of only Si and Ge elements may contain other elements (e.g., C, N, O, B, and P) as long as the total content of Si and Ge elements is within the above range. The total content of Si and Ge elements in the SiGe-containing material is preferably 90 to 100 mass %, more preferably 99 to 100 mass %, and even more preferably 99.9 to 100 mass %, relative to the total mass of the SiGe-containing material. In the SiGe-containing material, the content of Ge elements (Ge / (Si+Ge)) relative to the total content of Si and Ge elements is preferably 80 atomic % or less, more preferably 65 atomic % or less. The lower limit of the content of Ge element relative to the total content of Si element and Ge element is preferably 5 atomic % or more, more preferably 20 atomic % or more. In this specification, "silicon (Si)-containing material" refers to a material containing Si element (e.g., silicon oxide, SiN, polysilicon, etc.) that is different from the above-mentioned SiGe-containing material and does not substantially contain Ge element. "Substantially not containing Ge element" means that the content of Ge element is less than 5 atomic % (preferably 0 atomic %) with respect to all atoms of the material. The Si-containing material is preferably a material composed essentially of Si element only. "Substantially" means that the content of Si element is 90 atomic % or more with respect to all atoms of the material. In a material composed essentially of Si element only, other elements (e.g., C element, N element, O element, B element, P element, etc., excluding Ge element) may be contained as long as the content of Si element is within the above range.

[0014] In this specification, when there are a plurality of substituents, linking groups, etc. (hereinafter referred to as "substituents, etc.") represented by a specific symbol, or when a plurality of substituents, etc. are simultaneously specified, unless otherwise specified, it means that the respective substituents, etc. may be the same or different from each other. This also applies to the specification of the number of substituents, etc.

[0015] In this specification, "ppm" means "parts-per-million (10 －６ ) and "ppb" stands for "parts-per-billion (10 －９ ) and "ppt" stands for "parts-per-trillion (10 －１２ In this specification, 1 Å (angstrom) corresponds to 0.1 nm.

[0016] Unless otherwise specified, each component of the drug solution described in this specification may be ionized in the drug solution or may form a salt.

[0017] The chemical solution of the present invention is a chemical solution used for treating a workpiece having two SiGe-containing materials with different Ge concentrations, and contains water, hydrogen chloride, and hydrogen peroxide, wherein the mass ratio of the hydrogen peroxide content to the hydrogen chloride content is 0.20 or more, and the mass ratio of the water content to the hydrogen chloride content is 130 to 560.

[0018] The reason why the chemical solution having the above-mentioned configuration can solve the problem of the present invention is not entirely clear, but the inventors speculate as follows. Note that the following speculation does not limit the mechanism by which the effect is obtained. In other words, even if the effect is obtained by a mechanism other than the one described below, it is included in the scope of the present invention. In the chemical solution of the present invention, by containing predetermined amounts of hydrogen chloride and hydrogen peroxide, chlorine (Cl ２ It is presumed that a predetermined amount of chlorine is generated, and this chlorine reacts preferentially with SiGe-containing materials with a high Ge concentration in the workpiece, resulting in selective removal of at least a portion of the SiGe-containing materials with a high Ge concentration. Hereinafter, the ability to more selectively remove SiGe-containing materials with a high Ge concentration from a workpiece having two types of SiGe-containing materials with different compositions will also be simply referred to as "the effect of the present invention is superior."

[0019] Depending on the application, the chemical solution of the present invention may also preferably have excellent SiGe selective solubility. In this specification, "SiGe selective solubility" refers to the ability to selectively remove SiGe-containing materials relative to Si-containing materials when used on a workpiece having two SiGe-containing materials with different Ge concentrations and a Si-containing material. The chemical solution of the present invention is likely to exhibit excellent SiGe selective solubility by virtue of the specific unsaturated compound being adsorbed to the Si-containing materials.

[0020] [Water] The chemical solution of the present invention contains water. The water content is not particularly limited, and in terms of better effects of the present invention, it is preferably 80.00 mass% or more, more preferably 90.00 mass% or more, and even more preferably 95.00 mass% or more, relative to the total mass of the chemical solution. The upper limit of the water content is not particularly limited, and it is preferably 99.99 mass% or less, more preferably 99.90 mass% or less.

[0021] [Hydrogen Chloride] The chemical solution of the present invention contains hydrogen chloride (HCl). In the chemical solution of the present invention, the mass ratio of the water content to the hydrogen chloride content is 130 to 560.

[0022] The content of hydrogen chloride is not particularly limited, and is preferably 0.01% by mass or more, and more preferably 0.10% by mass or more, relative to the total mass of the chemical solution, from the viewpoint of obtaining a more excellent effect of the present invention. The upper limit of the content of hydrogen chloride is not particularly limited, and is preferably 2.00% by mass or less, and more preferably 1.00% by mass or less, relative to the total mass of the chemical solution, from the viewpoint of obtaining a more excellent effect of the present invention.

[0023] [Hydrogen Peroxide] The chemical solution of the present invention contains hydrogen peroxide (H ２ O ２ In the chemical solution of the present invention, the mass ratio of the content of hydrogen peroxide to the content of hydrogen chloride is 0.20 or more. In particular, in terms of more excellent effects of the present invention, the mass ratio is preferably 0.20 to 4.50, more preferably 0.40 to 4.45, and even more preferably 0.50 to 4.40.

[0024] The content of hydrogen peroxide is not particularly limited, and is preferably 0.01% by mass or more, and more preferably 0.10% by mass or more, relative to the total mass of the chemical solution, from the viewpoint of providing a more excellent effect of the present invention. The upper limit of the content of hydrogen peroxide is not particularly limited, and is preferably 5.0% by mass or less, and more preferably 3.0% by mass or less, and even more preferably 1.0% by mass or less, relative to the total mass of the chemical solution, from the viewpoint of providing a more excellent effect of the present invention.

[0025] [Other Components] The chemical solution of the present invention may contain other components in addition to the above-mentioned components. ４ ＋ ) may be contained. The source of ammonium ions is not particularly limited, and ammonium ions may be contained as impurities in the raw materials used to produce the chemical solution of the present invention. For example, ammonium ions may be contained as impurities in hydrogen peroxide water containing hydrogen peroxide. The concentration of ammonium ions in the chemical solution of the present invention is not particularly limited, but is preferably 10 to 1000 ppb by mass, and more preferably 30 to 300 ppb by mass, relative to the total mass of the chemical solution of the present invention.

[0026] The chemical solution of the present invention may contain other components, for example, an organic solvent, an oxidizing agent, and a reducing agent.

[0027] [Physical properties of chemical solution] <pH> The pH of the chemical solution is not particularly limited, but is preferably 0.5 to 1.6, more preferably 0.6 to 1.5, and even more preferably 0.8 to 1.4. The pH of the chemical solution can be measured using a known pH meter by a method in accordance with JIS Z8802-1984. The measurement temperature is 25°C.

[0028] <Metal Content> The content (measured as ion concentration) of metals (e.g., metal elements Fe, Co, Na, Cu, Mg, Mn, Li, Al, Cr, Ni, Zn, Sn, and Ag) contained as impurities in the chemical solution is preferably 5 mass ppm or less, and more preferably 1 mass ppm or less, relative to the total mass of the chemical solution. In particular, the metal content is more preferably a value lower than 1 mass ppm, that is, a mass ppb order or less, particularly preferably 100 mass ppb or less, and most preferably less than 10 mass ppb. The lower limit is preferably 0.

[0029] <Insoluble Particles> The drug solution of the present invention preferably does not substantially contain insoluble particles. The term "insoluble particles" refers to particles of inorganic solids or organic solids that do not dissolve in the drug solution and ultimately exist as particles. The term "substantially does not contain insoluble particles" refers to a measurement composition obtained by diluting the drug solution 10,000 times with water, and the number of particles with a particle size of 50 nm or more contained in 1 mL of the measurement composition is 40,000 or less. The number of particles contained in the measurement composition can be measured in the liquid phase using a commercially available particle counter. Commercially available particle counters include those manufactured by Rion and PMS. A representative example of the former is the KS-19F, and a representative example of the latter is the Chem20. To measure larger particles, devices such as the KS-42 series and LiQuilaz II S series can be used. Examples of insoluble particles include particles of inorganic solids such as silica (including colloidal silica and fumed silica), alumina, zirconia, ceria, titania, germania, manganese oxide, and silicon carbide; and particles of organic solids such as polystyrene, polyacrylic resin, and polyvinyl chloride. Methods for removing insoluble particles from the chemical solution include, for example, purification treatments such as filtering. Furthermore, it is preferable that the chemical solution does not contain abrasive grains.

[0030] <Coarse particles> The chemical solution may contain coarse particles, but the content thereof is preferably low. Coarse particles refer to particles having a diameter (particle size) of 1 μm or more when the particle shape is considered to be a sphere. The coarse particles contained in the chemical solution include particles such as dust, dirt, organic solids, and inorganic solids contained as impurities in the raw material, as well as particles such as dust, dirt, organic solids, and inorganic solids brought in as contaminants during the preparation of the chemical solution, and which ultimately exist as particles without dissolving in the chemical solution.

[0031] The content of coarse particles in the chemical solution is preferably 100 or less, more preferably 50 or less, particles with a particle size of 1 μm or more per mL of the chemical solution. The lower limit is preferably 0 or more, more preferably 0.01 or more, per mL of the chemical solution. The content of coarse particles present in the chemical solution can be measured in the liquid phase using a commercially available measuring device that uses a light scattering liquid particle measuring method with a laser as a light source.

[0032] [Method for Producing the Chemical Solution] The chemical solution of the present invention can be produced by a known method. The method for producing the chemical solution of the present invention will be described in detail below.

[0033] <Solution Preparation Step> Examples of methods for preparing the chemical solution of the present invention include a method of mixing the above-mentioned components. The order and / or timing of mixing the above-mentioned components are not particularly limited, and examples include a method of sequentially adding hydrogen chloride, hydrogen peroxide, and, if necessary, optional components to a container containing water, followed by stirring to mix. Alternatively, the solution may be prepared by adjusting the pH of the mixed solution by adding a pH adjuster. Furthermore, when adding the components to a container, they may be added all at once, or may be added in multiple divided portions.

[0034] The stirring device and stirring method used to prepare the chemical solution may be a known device such as a stirrer or disperser. Examples of the stirrer include an industrial mixer, a portable stirrer, a mechanical stirrer, and a magnetic stirrer. Examples of the disperser include an industrial disperser, a homogenizer, an ultrasonic disperser, and a bead mill.

[0035] The mixing of the components in the chemical solution preparation step, the purification treatment described below, and the storage of the produced chemical solution are preferably carried out at 40° C. or lower, more preferably at 30° C. or lower. The lower limit is preferably 5° C. or higher, more preferably 10° C. or higher. By preparing, treating, and / or storing the chemical solution within the above temperature range, the performance can be maintained stably for a long period of time.

[0036] The drug solution of the present invention may be prepared as a kit in which the raw materials are divided into a plurality of parts. When the drug solution of the present invention is prepared as a kit, the raw materials may be mixed in a predetermined ratio at the time of use or before use to obtain the drug solution of the present invention. The drug solution may also be prepared as a concentrated solution. In this case, the diluted solution obtained by diluting with a dilution liquid before use is used. In other words, the kit may include the drug solution in the form of a concentrated solution and the dilution liquid.

[0037] (Purification) It is preferable to perform a purification treatment in advance on one or more of the raw materials used to prepare the chemical solution. Furthermore, if necessary, the chemical solution may be subjected to a purification treatment. The degree of purification is preferably such that the raw material has a purity of 99% by mass or more, and more preferably such that the purity of the raw solution has a purity of 99.9% by mass or more. The upper limit is preferably 99.9999% by mass or less.

[0038] Examples of purification methods include passing the raw material through an ion exchange resin or a reverse osmosis membrane (RO) membrane, reprecipitation, distillation of the raw material, and filtering. Any filter conventionally used for filtration can be used without particular limitation. Examples of materials constituting the filter include filters made of fluororesins such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA), polyamide resins such as nylon, polyallylsulfone (PAS), and polyolefin resins (including high-density or ultra-high molecular weight) such as polyethylene and polypropylene (PP). Among these materials, materials selected from the group consisting of polyethylene, polypropylene (including high-density polypropylene), fluororesins (including PTFE and PFA), and polyamide resins (including nylon) are preferred, with fluororesin filters being more preferred. Filtering the raw material using a filter made of these materials can effectively remove highly polar foreign matter that is likely to cause defects.

[0039] The purification treatment may be carried out by combining two or more of the above purification methods, or may be carried out multiple times.

[0040] (Container) The container for storing the above-mentioned chemical solution or kit is not particularly limited, and any known container can be used as long as corrosiveness by the liquid is not a problem. Specific examples of the container include the "Clean Bottle" series manufactured by Aicello Chemical Co., Ltd. and the "Pure Bottle" manufactured by Kodama Resin Industry Co., Ltd. In addition, for the purpose of preventing impurities from being mixed (contaminated) into the raw materials and chemical solution, it is also preferable to use a multilayer container whose inner wall has a six-layer structure made of six types of resin, or a multilayer container whose inner wall has a seven-layer structure made of six types of resin. Examples of such containers include, but are not limited to, the containers described in JP 2015-123351 A. In addition, the containers exemplified in paragraphs

[0121] to

[0124] of WO 2022 / 004217 can also be used as containers, and the contents of these containers are incorporated herein by reference.

[0041] The interior of these containers is preferably washed before filling with the chemical solution. The liquid used for washing is preferably one that has a reduced amount of metal impurities. After production, the chemical solution may be bottled in a container such as a gallon bottle or a coated bottle, and then transported and stored.

[0042] To prevent changes in the components of the drug solution during storage, the inside of the container may be purged with an inert gas (such as nitrogen or argon) with a purity of 99.99995% by volume or higher. A gas with a low moisture content is particularly preferred. During transportation and storage, the drug solution may be stored at room temperature, or the temperature may be controlled within the range of -20°C to 20°C to prevent deterioration.

[0043] The method for producing the chemical solution may further include a static elimination step of eliminating static electricity from the chemical solution.

[0044] [Uses] The chemical solution of the present invention is preferably used in the manufacture of semiconductor devices. More specifically, it is preferably for use in semiconductor devices. "For use in semiconductor devices" means that it is used during the manufacture of semiconductor devices. The chemical solution can be used in the manufacturing process of semiconductor devices, for example, to treat SiGe-containing materials, Si-containing materials, insulating films, resist films, anti-reflective films, etching residues, and ashing residues (hereinafter simply referred to as "residues") present on a substrate. The chemical solution may also be used to treat semiconductor substrates after chemical mechanical polishing. The chemical solution of the present invention can be suitably used as a liquid (etchant) for removing at least a portion of the SiGe-containing material with the higher Ge concentration from a workpiece containing two SiGe-containing materials with different Ge concentrations.

[0045] [Workpiece] The workpiece to be treated with the chemical solution of the present invention is a workpiece having two SiGe-containing materials with different Ge concentrations. By using the chemical solution of the present invention on the workpiece, at least a portion of the SiGe-containing material with a high Ge concentration can be selectively removed relative to the SiGe-containing material with a low Ge concentration. In the workpiece, the content of Ge elements (Ge / (Si+Ge)) relative to the total content of Si elements and Ge elements in the SiGe-containing material with a high Ge concentration is preferably 25 to 80 atomic %, more preferably 35 to 70 atomic %. In the workpiece, the content of Ge elements (Ge / (Si+Ge)) relative to the total content of Si elements and Ge elements in the SiGe-containing material with a low Ge concentration is preferably 5 to 35 atomic %, more preferably 10 to 30 atomic %. In addition, in the workpiece, the difference between the Ge element content in the SiGe-containing material with a high Ge concentration and the Ge element content in the SiGe-containing material with a low Ge concentration is preferably 5 atomic % or more, more preferably 10 atomic % or more. There is no particular upper limit, but it is often 50 atomic % or less.

[0046] The workpiece is not particularly limited as long as it has two SiGe-containing materials with different Ge concentrations. Typically, two SiGe-containing materials with different Ge concentrations are disposed on a substrate. In this specification, "on a substrate" includes any of the front, back, side, and grooves of the substrate. Furthermore, "a predetermined material is disposed on a substrate" includes cases where a predetermined material is directly present on the surface of the substrate, as well as cases where a predetermined material is present on the substrate via another layer. Furthermore, "two SiGe-containing materials with different Ge concentrations are disposed on a substrate" refers to any form of existence as long as two SiGe-containing materials with different Ge concentrations are simultaneously present on the substrate. For example, the two SiGe-containing materials may be in contact with each other, or may be in contact via another layer or member. Alternatively, the two SiGe-containing materials may be present on the same substrate but not in contact with each other. The form of the SiGe-containing materials on the substrate may be any of a film, wiring, plate, column, and particle. If the SiGe-containing materials are in a film form, their thickness is not particularly limited, and may be, for example, 1 to 50 nm. The SiGe inclusions may be located on only one or both major surfaces of the substrate, may be located over the entire major surface of the substrate, or may be located over a portion of the major surface of the substrate, or the substrate may have three or more SiGe inclusions with different Ge concentrations.

[0047] The workpiece may further contain Si-containing materials. By using the chemical solution of the present invention on a workpiece having a Si-containing material and two SiGe-containing materials with different Ge concentrations, at least a portion of the SiGe-containing material can be selectively removed relative to the Si-containing material. In many cases, the at least a portion of the SiGe-containing material is a portion or all of the SiGe-containing material with a high Ge concentration. The form of the Si-containing material on the substrate may be any of a film, a wiring, a plate, a column, and a particle.

[0048] The size, thickness, shape, and layer structure of the substrate are not particularly limited and can be appropriately selected as desired. The substrate may be either a single layer or a multilayer. Examples of the substrate include metal substrates, semiconductor substrates, conductive substrates other than metal, metal oxide substrates, glass substrates, and resin substrates, with semiconductor substrates being preferred. Examples of semiconductor substrates include semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FEDs (Field Emission Displays), substrates for optical disks, substrates for magnetic disks, and substrates for magneto-optical disks. Examples of materials constituting the semiconductor substrate include silicon, germanium, and III-V group compounds such as GaAs, as well as combinations thereof.

[0049] 1 , the form of the workpiece may be, for example, a workpiece 200 including a substrate 202 and first SiGe-containing materials 204 and second SiGe-containing materials 206 alternately stacked on the substrate 202. The first SiGe-containing materials 204 and the second SiGe-containing materials 206 have different Ge concentrations, with the Ge concentration of the first SiGe-containing materials 204 being higher than the Ge concentration of the second SiGe-containing materials. Note that while FIG. 1 shows an embodiment in which the workpiece 200 includes a plurality of first SiGe-containing materials 204 and second SiGe-containing materials 206, only one layer of either or both of the plurality of first SiGe-containing materials 204 and the plurality of second SiGe-containing materials 206 may be present. 1 shows portions on the substrate 202 where neither the first SiGe inclusions 204 nor the second SiGe inclusions 206 are present, but such portions may be covered with either the first SiGe inclusions 204 or the second SiGe inclusions 206. In FIG. 1, the first SiGe inclusions 204 are disposed directly on the substrate 202, but they may be disposed via another layer. The second SiGe inclusions 206 may be supported by another material (not shown).

[0050] The workpiece may include, in addition to the SiGe-containing and Si-containing materials, other layers and / or structures as desired. For example, the substrate may include one or more components selected from the group consisting of metal wiring, a metal hard mask, a gate electrode, a source electrode, a drain electrode, an insulating layer, a ferromagnetic layer, and a non-magnetic layer. The substrate may include an exposed integrated circuit structure. The integrated circuit structure may include, for example, interconnect mechanisms such as metal wiring and dielectric materials. Examples of metals and alloys used in the interconnect mechanisms include aluminum, copper-aluminum alloys, copper, nickel, nickel silicide, cobalt, cobalt silicide, ruthenium, platinum, gold, titanium, tantalum, tungsten, titanium nitride, and tantalum nitride. The substrate may include one or more layers of a material selected from the group consisting of silicon oxide, silicon nitride, silicon carbide, and carbon-doped silicon oxide.

[0051] The method for manufacturing the workpiece is not particularly limited. For example, the workpiece may be manufactured by forming an insulating film on a substrate, disposing a SiGe-containing material on the insulating film by a method such as sputtering, chemical vapor deposition (CVD), atomic layer deposition (ALD), or molecular beam epitaxy (MBE), and then performing a planarization process such as CMP.

[0052] Examples of applications of the workpiece include DRAM (Dynamic Random Access Memory), FRAM (registered trademark) (Ferroelectric Random Access Memory), MRAM (Magnetoresistive Random Access Memory), PRAM (Phase Change Random Access Memory), logic circuits, and processors. Among these, the workpiece is preferably one used for manufacturing a semiconductor device. That is, the chemical solution is preferably used in a process for manufacturing a semiconductor device. As an element obtained by applying the chemical solution to the workpiece, a field effect transistor (FET) is preferred, and a gate-all-around-FET (GAA-FET) is more preferred. That is, the object to be processed is preferably one obtained during the manufacturing process of a GAA-FET.

[0053] [Method for treating a workpiece] A method for treating a workpiece using the chemical solution of the present invention can be a method of contacting the workpiece with the chemical solution of the present invention. By contacting the workpiece with the chemical solution, SiGe-containing materials with a high Ge concentration in the workpiece are selectively removed (etched). Furthermore, when the workpiece has two SiGe-containing materials and a Si-containing material with different Ge concentrations, the SiGe-containing materials in the workpiece can also be selectively removed (etched) by appropriately adjusting the composition of the chemical solution.

[0054] Methods for contacting the workpiece with the chemical solution include, for example, immersing the workpiece in the chemical solution contained in a tank, spraying the chemical solution onto the workpiece, flowing the chemical solution over the workpiece, and combinations of these methods, and the method of immersing the workpiece in the chemical solution is preferred.

[0055] Furthermore, in order to further increase the treatment speed with the chemical solution, a mechanical stirring method may be used, such as a method of circulating the chemical solution above the workpiece, a method of passing or spraying the chemical solution above the workpiece, or a method of stirring the chemical solution by ultrasonic waves or megasonics.

[0056] The treatment time using the chemical solution can be adjusted as appropriate. The treatment time (contact time between the chemical solution and the treated object) is preferably 0.5 to 60 minutes, more preferably 1 to 20 minutes. The temperature of the chemical solution during treatment is preferably 10 to 120°C, more preferably 50 to 100°C, even more preferably 60 to 80°C, and particularly preferably 65 to 80°C.

[0057] When processing the workpiece, only a portion or all of the SiGe-containing material with a high Ge concentration in the workpiece may be removed. Alternatively, a portion of the Si-containing material with a low Ge concentration in the workpiece may be intentionally or unavoidably removed. The workpiece 200 shown in FIG. 2 is one example of the workpiece 200 shown in FIG. 1 after being processed by this processing method. In this case, the dissolution rate of the second SiGe-containing material 206 with a low Ge concentration is sufficiently lower than that of the first SiGe-containing material 204 with a high Ge concentration, and a portion of the first SiGe-containing material 204 is dissolved from the side, forming a recess.

[0058] This processing method may, if necessary, include a rinsing step in which the object to be processed is rinsed using a rinse liquid. Examples of the rinsing method include a method in which the object to be processed is brought into contact with the rinse liquid. As a method in which the object to be processed is brought into contact with the rinse liquid, the above-mentioned method in which the object to be processed is brought into contact with the chemical liquid can be similarly applied.

[0059] The rinsing step may be followed by a drying step, if necessary. The drying method is not particularly limited, but examples thereof include spin drying, flowing a dry gas over the substrate, heating the substrate with a heating means such as a hot plate or an infrared lamp, IPA (isopropyl alcohol) vapor drying, Marangoni drying, Rotagoni drying, and combinations thereof.

[0060] [Method for Manufacturing a Semiconductor Device] The above-described method for processing a workpiece can be suitably applied to a method for manufacturing a semiconductor device. The above-described processing method may be performed before or after other processes performed on the substrate. The above-described cleaning method may be incorporated into other processes, or the above-described processing method may be incorporated into other processes. Examples of other processes include processes for forming structures such as metal wiring, gate structures, source structures, drain structures, insulating films, ferromagnetic layers, and nonmagnetic layers (e.g., layer formation, etching, chemical mechanical polishing, and modification), resist formation processes, exposure processes, removal processes, heat treatment processes, cleaning processes, and inspection processes.

[0061] The above processing method may be performed at any stage of a back end process (BEOL: Back end of the line), a middle process (MOL: Middle of the line), or a front end process (FEOL: Front end of the line), and is preferably performed in a front end process or a middle process.

[0062] The present invention will be described in more detail below with reference to the following examples. The materials, amounts used, ratios, treatment details, and treatment procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples. Furthermore, all of the components used in the examples and comparative examples were classified as semiconductor grade or equivalent high purity grade.

[0063] [Preparation of Chemical Solutions] Chemical solutions for each Example and Comparative Example were prepared by mixing the components (water, hydrogen chloride, hydrogen peroxide, etc.) listed in the table below so that the content of each component was the value shown in the table below. Note that hydrochloric acid and aqueous hydrogen peroxide, which will be described later, were used as sources of hydrogen chloride and hydrogen peroxide, and the amounts of each source used were adjusted to achieve the contents listed in the table. It was also confirmed that the chemical solutions produced in each Example contained 100 ppb by mass of ammonium ions. The components used in preparing the chemical solutions were as follows: Hydrochloric acid (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) Hydrogen peroxide solution (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.)

[0064] [Evaluation] According to the procedure described below, the solubility of each chemical solution was measured for a SiGe-containing material with a high Ge concentration, a SiGe-containing material with a low Ge concentration, and a Si-containing material, and the etching selectivity was evaluated.

[0065] A substrate on which silicon germanium (Si:Ge=75:25 (element ratio)) is laminated to a thickness of 30 nm, a substrate on which silicon germanium (Si:Ge=35:65 (element ratio)) is laminated to a thickness of 30 nm, a substrate on which polysilicon (Si) is laminated to a thickness of 100 nm, and a substrate on which silicon oxide (SiO ２ A substrate on which a 100 nm thick silicon nitride (SiN) film was laminated and a substrate on which a 300 nm thick silicon nitride (SiN) film was laminated were fabricated, and these substrates were each cut into 2 x 2 cm squares to fabricate test specimens (SeGe65 test specimen, SeGe25 test specimen, SiN test specimen, silicon oxide test specimen, and polysilicon test specimen). The SeGe65 test specimen (silicon germanium (Si:Ge = 35:65 (element ratio))) was immersed for 10 seconds in a treatment solution at a temperature listed in the table of the example or comparative example. The SeGe25 test specimen (silicon germanium (Si:Ge = 75:25 (element ratio))) was immersed for 1 minute in a treatment solution at a temperature listed in the table of the example or comparative example. The other test specimens were immersed for 2 minutes in a treatment solution at a temperature listed in the table of the example or comparative example. Before and after the above immersion test, the SiGe film, Si film, SiO ２The film thickness of the SiN film was measured using an optical film thickness meter, Ellipsometer M-2000 (manufactured by J.A. Woollam Co., Ltd.) The dissolution rate (Å / min) of each film when using each treatment solution was calculated from the measured film thickness before and after immersion.

[0066] [Results] The composition of each chemical solution and the evaluation results are shown in the table below. In the table below, the "hydrogen chloride" column represents the content (mass%) of hydrogen chloride relative to the total mass of the chemical solution, and the "hydrogen peroxide" column represents the content (mass%) of hydrogen peroxide relative to the total mass of the chemical solution. In the table below, the "hydrogen peroxide / hydrogen chloride" column represents the mass ratio of the hydrogen peroxide content to the hydrogen chloride content, and the "water / hydrogen chloride" column represents the mass ratio of the water content to the hydrogen chloride content. In the table below, the "pH" column represents the pH of the chemical solution. In the table below, the "temperature (°C)" column represents the temperature (°C) of the chemical solution in contact with each test specimen. In the table below, the "selectivity ratio (SiGe65 / SiGe25)" column represents the ratio of the dissolution rate of SiGe65 to the dissolution rate of SiGe25. The larger this value, the more selectively SiGe-containing materials with a high Ge concentration can be removed over SiGe-containing materials with a low Ge concentration. In the chemical solutions of the Examples and Comparative Examples, the only component (the remainder) other than hydrogen chloride, hydrogen peroxide, and ammonium ions was water. In the tables below, the notation "<X" means "less than X," and the notation ">X" means "greater than X."

[0067]

[0068]

[0069] From the above table, it was confirmed that the chemical solution of the present invention can selectively remove SiGe-containing materials with a high Ge concentration from a processing object having two types of SiGe-containing materials with different compositions. Furthermore, from a comparison of Examples 1 to 3, it was confirmed that the effect is even better when the temperature of the chemical solution is 65°C or higher.

[0070] 200 Processed object 202 Substrate 204 First SiGe-containing material 206 Second SiGe-containing material

Claims

1. A chemical solution used on a workpiece having two silicon-germanium-containing materials with different germanium concentrations, the chemical solution containing water, hydrogen chloride, and hydrogen peroxide, wherein the mass ratio of the hydrogen peroxide content to the hydrogen chloride content is 0.20 or more, and the mass ratio of the water content to the hydrogen chloride content is 130 to 560.

2. The drug solution according to claim 1, having a pH of 0.5 to 1.

6.

3. The chemical solution according to claim 1, further comprising ammonium ions.

4. The chemical solution according to claim 1, which is used for treating two silicon-germanium containing materials having different germanium concentrations, and a silicon containing material different from the silicon-germanium containing materials.

5. A method for treating an object to be treated, comprising a step of contacting the object to be treated, which has two silicon-germanium-containing materials having different germanium concentrations, with the chemical solution according to any one of claims 1 to 4.

6. The method for treating an object to be treated according to claim 5, wherein the temperature of the chemical solution is 60°C or higher.

7. A method for manufacturing a semiconductor device, comprising the method for treating an object as set forth in claim 5.

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