Method and apparatus for doping semiconductor substrates

Abstract

The present invention provides a wet treatment method for doping a semiconductor substrate, which exhibits excellent diffusivity of dopant elements within the semiconductor substrate. [Solution] A method for doping a semiconductor substrate, comprising: a preparation step of preparing adjusted water with a pH of 2 or higher and an adjusted concentration of dopant elements; a coating step of coating a semiconductor substrate with the adjusted water; and a heating step of heating the semiconductor substrate coated with the adjusted water, wherein the preparation step of the adjusted water comprises: an addition step of adding a concentration adjusting agent containing a dopant component to the water to be treated, with the amount of addition controlled; and a pH adjustment step of adjusting the pH of the water to be treated before or after the addition of the concentration adjusting agent.

Description

Technical Field

[0001] The present disclosure relates to a method for doping a semiconductor substrate and a doping processing apparatus.

Background Art

[0002] Substrates used in semiconductor devices such as transistors, diodes, and solar cells are manufactured by diffusing dopant elements such as phosphorus or boron into the semiconductor substrate. As a method for diffusing dopant elements into the semiconductor substrate, for example, a dry processing method such as an ion implantation method is used (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Applying a dry processing method to a semiconductor substrate having a complex structure tends to be difficult. Therefore, the inventor considered a method of applying an aqueous solution containing a dopant element to the surface of a semiconductor substrate as a wet processing method that is considered to be easy to apply to a semiconductor substrate having a complex structure. The inventor has found that in this case, the diffusibility of the dopant element in the semiconductor substrate may not be sufficient.

[0005] An object of the present disclosure is to provide a method for doping a semiconductor substrate, which is a wet processing method and has excellent diffusibility of a dopant element in the semiconductor substrate.

Means for Solving the Problems

[0006] One embodiment of the semiconductor substrate doping method of the present disclosure comprises a preparation step of preparing adjusted water with a pH of 2 or higher in which the concentration of a dopant element has been adjusted; a coating step of coating the adjusted water onto a semiconductor substrate; and a heating step of heating the semiconductor substrate coated with the adjusted water. The preparation step of the adjusted water comprises an addition step of adding a concentration adjusting agent containing a dopant component to the water to be treated, with the amount of addition controlled; and a pH adjustment step of adjusting the pH of the water to be treated before or after the addition of the concentration adjusting agent. [Effects of the Invention]

[0007] The semiconductor substrate doping method described herein is a wet treatment method and exhibits excellent diffusivity of dopant elements in the semiconductor substrate. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic block diagram showing one embodiment of a doping processing device. [Figure 2] Figure 2 is a schematic block diagram showing one embodiment of a doping apparatus. [Figure 3] Figure 3 is a schematic block diagram showing one embodiment of a doping processing device. [Figure 4] Figure 4 is a schematic block diagram showing one embodiment of a doping processing device. [Modes for carrying out the invention]

[0009] In this specification, the numerical range N1 to N2 means N1 or greater and N2 or less. In this specification, if the units of the numbers before and after the "~" indicating a numerical range are the same, the unit of the number before the "~" may be omitted.

[0010] [Doping apparatus for semiconductor substrates] The semiconductor substrate doping apparatus described herein is A device for producing adjusted water with a pH of 2 or higher, in which the concentration of dopant elements has been adjusted, An application device for applying the above-mentioned adjustment water to a semiconductor substrate, a heating device for heating the semiconductor substrate coated with the above-mentioned adjustment water, and is provided with.

[0011] <Manufacturing device for adjustment water> The above-mentioned manufacturing device is a device for manufacturing adjustment water in which the concentration of a dopant element is adjusted, which is used for application to a semiconductor substrate in the manufacturing process of a semiconductor or a semiconductor device.

[0012] The above-mentioned manufacturing device includes a concentration adjustment device for controlling the addition amount of a concentration adjuster containing a dopant component and adding it to the water to be treated, and a pH adjustment device for adjusting the pH of the water to be treated before or after the addition of the concentration adjuster. The above-mentioned manufacturing device may further include a water quality monitoring device for measuring the concentration of a dopant element in the water to be treated or the adjustment water to which the above-mentioned concentration adjuster has been added.

[0013] The above-mentioned manufacturing device may include an impurity component removal device for selectively removing at least a part of an unwanted impurity component different from the target dopant component from the water to be treated or the concentration adjuster to which the above-mentioned concentration adjuster may be added.

[0014] The above-mentioned manufacturing device performs treatments such as adding a concentration adjuster described below to raw material water such as ultrapure water to manufacture the target adjustment water. In this specification, raw material water such as ultrapure water and aqueous solutions obtained by adding a concentration adjuster to the raw material water are collectively referred to as "water to be treated".

[0015] The above-mentioned manufacturing device can manufacture adjustment water containing a target dopant element or dopant component (for example, it may be a metal element or ion) in a wide concentration range from water such as ultrapure water, and in one embodiment, unwanted impurity components (for example, it may be a metal element or ion) are removed or their concentration is reduced.

[0016] The dopant component is a component containing a dopant element that is doped into a semiconductor substrate in, for example, the manufacturing process of a semiconductor or a semiconductor device. By using such adjusted water, the semiconductor substrate can be doped by a wet processing method. For example, by applying the adjusted water obtained by the above manufacturing apparatus to an appropriate location on the surface of the semiconductor substrate in an appropriate amount in the doping process in the manufacturing process of a semiconductor or a semiconductor device, the dopant element constituting the dopant component can be doped to an appropriate location in an appropriate amount.

[0017] Ultrapure water is produced, for example, by removing ionic substances, organic substances, dissolved gases, fine particles, etc. from raw water. Examples of raw water include tap water, well water, river water, lake water, and industrial water. As ultrapure water, for example, water having a resistivity of 18.1 MΩ·cm or more, fine particles: 1000 or less per liter with a particle size of 50 nm or more, viable bacteria: 1 or less per liter, TOC (Total Organic Carbon): 1 μg / L or less, total silicon: 0.1 μg / L or less, metals: 1 ng / L or less, ions: 10 ng / L or less, hydrogen peroxide: 30 μg / L or less, and water temperature: 25 ± 2°C is preferable, but it is not particularly limited.

[0018] The adjusted water produced using the above manufacturing apparatus is transferred to its place of use (use point; UP). Examples of the use point include a coating apparatus for applying the above adjusted water to a semiconductor substrate in the manufacturing process of a semiconductor or a semiconductor device, and a heating apparatus for heating the semiconductor substrate coated with the above adjusted water.

[0019] ≪Concentration Adjusting Device for Dopant Element≫ The above manufacturing apparatus includes a concentration adjusting device for a dopant element. The above concentration adjusting device is a device for adding a concentration adjusting agent containing a dopant component to the water to be treated, such as ultrapure water, while controlling the addition amount thereof. For example, it is a device for adding an aqueous solution containing a dopant component to the water to be treated.

[0020] The concentration adjusting agent contains a dopant component. The dopant component contains a dopant element (hereinafter also simply referred to as "dopant") as a constituent element, and is a component for containing the target dopant element in the concentration adjusting agent and the adjusted water produced. One type of dopant component may be used, or two or more types may be used. The concentration adjusting agent is, for example, an aqueous solution containing the above-mentioned dopant component.

[0021] The dopant component described above is not particularly limited as long as it is a component that has been conventionally used for doping semiconductor substrates. For example, it may be a compound containing an n-type dopant or a compound containing a p-type dopant. The aqueous solution described above is, for example, an aqueous solution containing at least one selected from the group consisting of compounds containing an n-type dopant and compounds containing a p-type dopant.

[0022] Examples of n-type dopants include phosphorus, arsenic, sulfur, tin, and antimony. Examples of p-type dopants include boron, zinc, magnesium, gallium, indium, and aluminum. Preferred dopant components include, for example, phosphorus compounds, arsenic compounds, and boron compounds.

[0023] Examples of phosphorus compounds include phosphoric acid, phosphorous acid, diphosphorous acid, polyphosphoric acid, and diphosphorus pentoxide. Other examples include phosphorous acid esters such as trimethyl phosphate and triethyl phosphate, phosphate esters such as trimethyl phosphate and triethyl phosphate, tris(trialkylsilyl) phosphates such as tris(trimethylsilyl) phosphate, and tris(trialkylsilyl) phosphates such as tris(trimethylsilyl) phosphate.

[0024] Examples of arsenic compounds include arsenic trioxide sodium sulfate, arsenic acid, arsenous acid, and trialkyl arsenates such as triethoxyarsenic and tri-n-butoxyarsenic.

[0025] Examples of boron compounds include boric acid, metaboric acid, boronic acid, perboric acid, subboric acid, diboron trioxide, trialkyl borate, tetrahydroxydiborane, monoalkoxytrihydroxydiborane, dialkoxydihydroxydiborane, trialkoxymonohydroxydiborane, and tetraalkoxydiborane.

[0026] The concentration of dopant elements in the adjusted water obtained by the above manufacturing apparatus is set appropriately according to the intended use of the adjusted water and is not particularly limited. The concentration of dopant elements in the adjusted water is preferably 100,000 mg / L or less, more preferably 0.1 to 50,000 mg / L, even more preferably 0.5 to 20,000 mg / L, and particularly preferably 1 to 13,000 mg / L. The above concentration adjustment apparatus, for example, adds a concentration adjusting agent to the water to be treated so that the concentration of dopant elements in the adjusted water falls within the above range.

[0027] The above-described concentration adjustment device is, for example, a device that measures and supplies a concentration adjusting agent to a transfer line of water to be treated, such as ultrapure water. The above-described concentration adjustment device comprises, for example, a tank containing the concentration adjusting agent and a supply line that supplies the concentration adjusting agent from the tank to the transfer line, and may further include a pump to adjust the supply rate of the concentration adjusting agent, if desired. As will be described later, in one embodiment, the concentration adjustment device may further include a device for removing impurity components. The concentration adjustment device may, for example, include a tank containing a concentration adjusting agent, the removal device, and a supply line that supplies the concentration adjusting agent from the tank through the removal device to a transfer line. The above concentration adjustment device may be equipped with two or more of the above tanks, depending on the type of concentration adjusting agent.

[0028] A tank containing a concentration adjusting agent may be equipped with at least one selected from the group consisting of a device for purging the inside of the tank using an inert gas (e.g., N2 gas) and a degassing membrane for removing dissolved gases (e.g., dissolved oxygen) from the concentration adjusting agent inside the tank.

[0029] Examples of pumps include diaphragm pumps. Alternatively, a pressurized extrusion pump may be used, in which the concentration adjusting agent is placed in a tank together with an inert gas (e.g., N2 gas), and the concentration adjusting agent is pushed out by the pressure of the inert gas.

[0030] <<Device for removing impurities>> In one embodiment, the above-described manufacturing apparatus includes a device for removing impurity components. The above-described removal device selectively removes at least a portion of impurity components (for example, at least one selected from the group consisting of metal elements and ions) different from the dopant components from the water to be treated, which may contain the concentration adjusting agent, or from the concentration adjusting agent itself. The impurity components here are components that are undesirable to be present in the adjusted water produced. In one embodiment, the above-described removal device can allow the dopant component to pass through while selectively removing the impurity component. Examples of impurity components include metallic elements and ions such as Al, Ca, Fe, Mg, Na, Ni, and Zn, as well as unintended dopant components.

[0031] The above-mentioned removal device preferably has a removal section corresponding to the type of impurity component to be removed. The above-mentioned removal device preferably has at least one selected from the group consisting of ion exchange resin, ion exchange membrane, nanofiltration membrane, and reverse osmosis membrane. Among these, ion exchange resin is preferred. Examples of ion exchange resins include cation exchange resin and anion exchange resin, and cation exchange resin is preferred from the standpoint of removing cationic metal ion impurities in the water to be treated or the concentration adjusting agent.

[0032] Examples of cation exchange resins include strongly acidic cation exchange resins such as sulfonic acid type and weakly acidic cation exchange resins such as carboxylic acid type. Examples of anion exchange resins include strongly basic anion exchange resins such as quaternary amine type and weakly basic anion exchange resins such as primary to tertiary amine type.

[0033] As the ion exchange resin, for example, a mixed resin of a cation exchange resin and an anion exchange resin may be used. This makes it possible to selectively remove unwanted dopant components (for example, dopant components other than boron compounds) depending on the type of dopant component being targeted (e.g., boron compounds) and the dopant components being unintended (e.g., dopant components other than boron compounds), for example, using an impurity removal device.

[0034] The ion exchange resin may be, for example, a gel-type resin.

[0035] The removal device described above may include an ion exchange resin column. The ion exchange resin column may have one stage or two or more stages.

[0036] The above-described removal device is, for example, a device that removes impurity components so that the concentration of impurity components in the water to be treated or the concentration adjusting agent is preferably 1 μg / L or less, more preferably 0.1 μg / L or less, even more preferably 0.01 μg / L or less, and particularly preferably 0.001 μg / L or less.

[0037] In one embodiment, the removal device is located upstream or downstream of the dopant element concentration adjustment device on the water transfer line, preferably downstream. This reduces the concentration of impurity components (e.g., metal elements, ions) in the water to be treated.

[0038] In one embodiment, the removal device is included within a dopant element concentration adjustment device. That is, in one embodiment, the concentration adjustment device may further include the removal device. This makes it possible to remove or reduce the concentration of impurity components in a concentration adjustment agent containing dopant components that is added to the water to be treated, and as a result, to remove or reduce the concentration of impurity components in the water to be treated.

[0039] ≪pH adjustment device and oxidation-reduction potential adjustment device≫ The above manufacturing apparatus further comprises a pH adjustment device for adjusting the pH of the water to be treated, such as ultrapure water. The pH adjustment device is a device that adjusts the pH of the water to be treated by measuring and supplying a pH adjusting agent to the water to be treated transfer line. The pH adjustment device comprises, for example, a tank containing the pH adjusting agent and a supply line that supplies the pH adjusting agent from the tank to the transfer line, and may further comprise a pump for adjusting the supply rate of the pH adjusting agent, if desired.

[0040] In one embodiment, the pH adjustment device adjusts the pH of the water to be treated so that the pH of the adjusted water is 2 or higher, preferably 3 to 11, more preferably 5 to 10, and even more preferably 7 to 10. In one embodiment, the pH adjustment device adjusts the pH of the water to be treated to 2 or higher, preferably 3 to 11, more preferably 5 to 10, and even more preferably 7 to 10. Adjusted water with such a pH has excellent diffusivity of dopant elements in semiconductor substrates, and by using this adjusted water, semiconductors or semiconductor devices with appropriate conductivity can be manufactured.

[0041] The above manufacturing apparatus may further include an oxidation-reduction potential adjustment device (hereinafter also referred to as "ORP adjustment device") for adjusting the oxidation-reduction potential (hereinafter also referred to as "ORP") of the water to be treated, such as ultrapure water. Preferably, the ORP adjustment device is located downstream of the pH adjustment device and upstream of the degassing device on the above transfer line. Therefore, the ORP of the water to be treated may be adjusted by the ORP adjustment device.

[0042] An ORP adjustment device is a device that adjusts the ORP of water to be treated by measuring and supplying an oxidation-reduction potential adjusting agent (hereinafter also referred to as "ORP adjusting agent") to the transfer line. An ORP adjustment device may further include, for example, a tank containing the ORP adjusting agent and a supply line that supplies the ORP adjusting agent from the tank to the transfer line, and optionally a pump to adjust the supply rate of the ORP adjusting agent.

[0043] pH-adjusted water obtained by adding a pH adjusting agent to ultrapure water has higher electrical conductivity than ultrapure water. Therefore, it is possible to suppress the charging of pipes and the liquid flowing within them, and to suppress the mixing of fine particles into the water being treated.

[0044] The above-mentioned tank may be equipped with at least one selected from the group consisting of a device for purging the inside of the tank using an inert gas (e.g., N2 gas) and a degassing membrane for removing dissolved gases (e.g., dissolved oxygen) from the pH adjusting agent or ORP adjusting agent inside the tank.

[0045] Examples of pumps include diaphragm pumps. Alternatively, a pressurized extrusion pump may be used, in which a pH adjuster or ORP adjuster is placed in a tank together with an inert gas (e.g., N2 gas), and the pH adjuster or ORP adjuster is pushed out by the pressure of the inert gas.

[0046] For pH adjustment devices and ORP adjustment devices, if the pH adjusting agent or ORP adjusting agent is a gas, a direct gas-liquid contact device such as a gas permeable membrane module or ejector may be used.

[0047] Examples of pH adjusting agents used to adjust the pH of the treated water or adjusted water to 7 or higher include aqueous solutions of alkaline compounds and gaseous alkaline compounds. Alkaline compounds are the active ingredients of pH adjusting agents. Examples of alkaline compounds include ammonia, tetramethylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium bicarbonate. An example of a gaseous alkaline compound is ammonia gas. One or more alkaline compounds may be used.

[0048] Among these, an aqueous ammonia solution or ammonia gas is preferred, and an aqueous ammonia solution is more preferred. By dissolving a small amount of ammonia in ultrapure water, for example, an effect of suppressing the dissolution of semiconductor materials and an effect of suppressing static charge can be obtained.

[0049] In one embodiment, the pH adjustment device adjusts the pH of the water to be treated to preferably 8 to 11. When the pH is 8 or higher, the generation of static electricity tends to be suppressed in various devices located downstream of the pH adjustment device. When the pH is 11 or lower, the corrosion of semiconductor substrates and the deterioration of membranes contained in degassing devices or gas dissolution membrane type devices tend to be suppressed.

[0050] Examples of pH adjusting agents used to adjust the pH of the treated water or adjusted water to less than 7 include aqueous solutions of acidic compounds such as hydrochloric acid, nitric acid, sulfuric acid, formic acid, acetic acid, and citric acid, as well as gases such as CO2 gas. Acidic compounds and carbon dioxide (CO2 gas) are the active ingredients of the pH adjusting agent. One type of acidic compound may be used, or two or more types may be used. The pH value is the value obtained when measured at 23°C using a known pH meter.

[0051] The pH adjuster is preferably a liquid, more preferably an aqueous solution of an alkaline compound, and even more preferably an aqueous solution of ammonia.

[0052] Examples of ORP adjusting agents for adjusting the oxidation-reduction potential of the treated water or adjusted water to a higher (+) level include aqueous solutions such as hydrogen peroxide, and gases such as ozone and oxygen. Examples of ORP adjusting agents for adjusting the oxidation-reduction potential of the treated water or adjusted water to a lower level include aqueous solutions of compounds such as oxalic acid, hydrogen sulfide, and potassium iodide, and gases such as hydrogen gas. One or more of the above compounds may be used. One or more of the above gases may be used. ORP values ​​are those measured at 23°C using a known ORP meter.

[0053] ≪Hydrogen Peroxide Removal Device≫ The above manufacturing apparatus may further include a hydrogen peroxide removal device. For example, it is preferable that at least a portion of the hydrogen peroxide is removed from the water to be treated to which the ORP adjusting agent is supplied. Therefore, it is preferable that the hydrogen peroxide removal device be located upstream of the ORP adjusting device on the transfer line, and more preferably upstream of both the pH adjusting device and the ORP adjusting device. By providing a hydrogen peroxide removal device, the ORP adjusting device can accurately control the ORP of the adjusted water.

[0054] A hydrogen peroxide removal apparatus includes, for example, a platinum group metal-supported resin column. The platinum group metal-supported resin column includes a resin (hereinafter also referred to as "carrier resin") and a platinum group metal supported on the resin. In the platinum group metal-supported resin column, hydrogen peroxide in the water to be treated, such as ultrapure water, is decomposed and removed by the catalytic action of the platinum group metal.

[0055] Examples of carrier resins include ion exchange resins. Among ion exchange resins, anion exchange resins are preferred. Platinum group metals are negatively charged, so they are stably supported on anion exchange resins and do not easily fall off. The exchange groups of the anion exchange resin are preferably of the OH type. OH type anion exchange resins have an alkaline resin surface, which promotes the decomposition of hydrogen peroxide.

[0056] Examples of platinum group metals include ruthenium, rhodium, palladium, osmium, iridium, and platinum. Platinum group metals may be used individually, in combination of two or more, as an alloy of two or more, or as a refined product of a naturally occurring mixture without separating it into individual elements. Among these, platinum, palladium, platinum / palladium alloys, or mixtures of two or more of these are preferable due to their strong catalytic activity. Nano-order fine particles of these metals are also preferable.

[0057] Pump The above manufacturing apparatus may further include a pump. Using a pump makes it easier to increase the flow velocity and water pressure. Preferably, the pump is one in which the amount of pressurization can be controlled. Examples of pumps include rotary positive displacement pumps that continuously perform suction and discharge by volume change, reciprocating positive displacement pumps that repeatedly perform suction and discharge by volume change, and centrifugal pumps that discharge liquid using centrifugal force or thrust generated by the rotation of an impeller or propeller inside the pump.

[0058] <<Degassing device>> The above manufacturing apparatus may further include a degassing device for degassing the water to be treated. The degassing device removes at least a portion of the dissolved gases in the water to be treated, thereby reducing the amount of dissolved gas. Examples of dissolved gases include dissolved oxygen and dissolved nitrogen.

[0059] The degassing device is preferably located downstream of the pH adjustment device, or downstream of both the pH adjustment device and the ORP adjustment device, on the transfer line described above. Such a manufacturing apparatus includes a degassing device that can suppress the generation of static electricity and prevent the accumulation of fine particles on the gas permeable membrane surface. Therefore, the inclusion of fine particles into the adjusted water can be suppressed.

[0060] As the degassing device, a membrane degassing device is preferred, and a membrane degassing device equipped with a gas permeable membrane is more preferred. In one embodiment, the membrane degassing device flows the water to be treated into one side (liquid phase chamber) of the gas permeable membrane, and reduces the pressure on the other side (gas phase chamber) with a vacuum pump, thereby removing at least a portion of the dissolved gas by allowing it to pass through the gas permeable membrane and move to the gas phase chamber side. The degassing device reduces the dissolved oxygen concentration in the water to be treated supplied to the gas dissolution membrane device to 0.1 mg / L or less.

[0061] By degassing the water to be treated afterward, rather than directly degassing the concentration adjusters, pH adjusters, and ORP adjusters, the risk of chemical leakage during vacuum degassing of these agents can be reduced.

[0062] A gas permeable membrane can be any membrane that allows gases such as oxygen, nitrogen, and vapor to pass through but not water. Examples of materials that make up the gas permeable membrane include polymer materials such as silicone rubber, polytetrafluoroethylene, polyvinylidene fluoride, polyolefin (e.g., polypropylene), and polyurethane. One polymer material may be used, or two or more may be used. Among these, at least one selected from the group consisting of polypropylene and polyvinylidene fluoride is preferred.

[0063] ≪Gas dissolution membrane type apparatus≫ The above manufacturing apparatus may further include a gas dissolution membrane apparatus. The gas dissolution membrane apparatus is preferably located downstream of the degassing apparatus on the transfer line described above. The gas dissolution membrane apparatus is, for example, a device that dissolves an inert gas into the degassed water to be treated via a gas permeable membrane. This stabilizes the properties of the water to be treated.

[0064] Examples of inert gases include nitrogen, argon, and helium.

[0065] In one embodiment, the gas dissolution membrane apparatus allows degassed water to be treated to flow through one side (liquid phase chamber) of a gas permeable membrane, and an inert gas to be supplied to the other side (gas phase chamber). This allows the inert gas to pass through the gas permeable membrane and move to the liquid phase side, where it can be dissolved in the water to be treated.

[0066] Examples of materials constituting the gas permeable membrane are as described above, and further examples are omitted in this section. Among the above materials, at least one selected from the group consisting of polypropylene and polyvinylidene fluoride is preferred.

[0067] The gas permeable membrane may be, for example, a hollow fiber membrane. In this case, the gas-dissolved membrane apparatus includes a hollow fiber membrane unit containing a hollow fiber membrane inside. Inside the hollow fiber membrane unit are connected a liquid supply pipe that supplies the degassed water to be treated to the hollow fiber membrane unit, a gas supply pipe that supplies an inert gas to the hollow fiber membrane unit, and a drain pipe that discharges the adjusted water in which the inert gas has dissolved.

[0068] ≪Water quality monitoring device≫ The above manufacturing apparatus preferably further includes a water quality monitoring device for the water to be treated or the adjusted water. The water quality monitoring device is a device that measures the water quality of the water to be treated or the adjusted water (for example, the concentration of dopant elements, the concentration of active ingredients of pH adjusters, and pH).

[0069] The water quality monitoring device is preferably located downstream of the dopant element concentration adjustment device on the water transfer line to be treated. The water quality monitoring device measures, for example, the concentration of dopant elements in the water to be treated or adjusted water to check whether the concentration of dopant elements is at a desired value, and / or measures the concentration or pH of the active ingredient of the pH adjuster to check whether these are at a desired value.

[0070] The water quality monitoring device is preferably located downstream of the concentration adjustment device on the water transfer line to be treated, and either upstream or downstream of the impurity component removal device.

[0071] The water quality monitoring device is preferably located downstream of the gas dissolution membrane device on the transfer line. The water quality monitoring device may, for example, measure at least one selected from the group consisting of the concentration of the active ingredient of the pH adjuster, the concentration of the active ingredient of the ORP adjuster, pH, oxidation-reduction potential (ORP), and the concentration of the inert gas in the water to be treated or adjusted, and monitor whether the concentration of the active ingredient, pH, ORP, or inert gas is at a desired value. The water quality monitoring device that measures the concentration of the dopant element may perform these measurements, or a different water quality monitoring device may perform these measurements.

[0072] The concentration of dopant elements in the treated water or adjusted water can be measured using a known pH meter or conductivity meter, or a metal element or ion detector. The pH, ORP, and inert gas concentrations in the treated water or adjusted water can be measured using a known pH meter, an known ORP meter, and a known gas concentration meter, respectively. The concentration of the above-mentioned active ingredients can be measured using a known conductivity meter.

[0073] ≪Control device≫ The above manufacturing apparatus preferably further includes a control device along with a water quality monitoring device. A control device is, for example, a computer. The water quality monitoring device may be connected to the control device, for example, electrically or wirelessly. The control device may be connected, for example, electrically or wirelessly, to at least one device selected from the group consisting of the concentration adjustment device, pH adjustment device, ORP adjustment device, and gas dissolution membrane type device.

[0074] The control device is, for example, a device that controls the amount or rate at which a concentration adjusting agent containing a dopant component is added to a dopant element concentration adjusting device, based on the water quality of the treated water or adjusted water measured by a water quality monitoring device (e.g., concentration of dopant elements, pH, or conductivity).

[0075] The control device can be used to control the adjusted water so that it has a set concentration of the dopant element. Such control of concentration and other parameters by the control device can be achieved by feedback control such as PI control or PID control, as well as by other well-known methods.

[0076] The control device can, for example, transmit a signal to a dopant element concentration adjustment device based on the water quality (e.g., dopant element concentration, pH, or conductivity) measured by a water quality monitoring device, and control the amount or rate at which the concentration adjusting agent is added to the device using a pump or the like.

[0077] The control device may be, for example, a device that controls the amount or rate at which a pH adjusting agent is added in a pH adjusting device based on the water quality of the treated water or adjusted water measured by a water quality monitoring device, or a device that controls at least one selected from the group consisting of the amount or rate at which an ORP adjusting agent is added in an ORP adjusting device, and the amount or rate at which an inert gas is added in a gas-dissolved membrane device.

[0078] The control device can control the adjusted water so that it has at least one selected from the group consisting of a set concentration of the active ingredient, a set pH value, a set ORP value, and a set concentration of the inert gas. Such control by the control device, which selects at least one from the group consisting of the concentration of the active ingredient, pH, ORP, and the concentration of the inert gas, can be controlled by known methods, such as feedback control such as PI control or PID control.

[0079] The control device can transmit a signal to the pH adjuster based on the water quality measured by the water quality monitoring device (for example, the concentration or pH of the active ingredient in the pH adjuster), and control the amount or rate at which the pH adjuster is added or supplied in the pH adjuster using a pump or the like. The control device can transmit a signal to the ORP adjustment device based on the water quality measured by the water quality monitoring device (for example, the concentration of the active ingredient of the ORP adjustment agent or ORP), and control the amount of ORP adjustment agent added or the supply rate in the ORP adjustment device using a pump or the like. The control device, for example, transmits a signal to the inert gas mass flow controller based on the water quality (e.g., the concentration of inert gas) measured by the water quality monitoring device, and the mass flow controller can control the amount or rate of inert gas added or supplied from the inert gas supply device.

[0080] ≪Temperature control device≫ The above manufacturing apparatus may further include a temperature control device. The location of the temperature control device in the above manufacturing apparatus is not particularly limited. Examples of temperature control devices include heat exchangers.

[0081] ≪Flow Channel≫ The flow paths (e.g., transfer lines or supply lines) through which the water to be treated, such as ultrapure water, adjusted water, concentration adjusters, pH adjusters, ORP adjusters, and inert gases flow in the above-mentioned manufacturing apparatus are composed of pipes, for example. Equipment such as tanks, pumps, fittings, and valves may be provided in these flow paths.

[0082] Examples of materials used to construct the piping include polymer materials such as polyvinyl chloride (PVC), polyphenylene sulfide (PPS), polyvinylidene fluoride (PVDF), tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA), and polypropylene (PP); as well as fiber-reinforced plastics (FRP) and stainless steel. Among these, PFA is preferred.

[0083] <Coating device> The doping apparatus described above further comprises a coating apparatus for applying the prepared water to a semiconductor substrate at the point of use of the prepared water. The semiconductor substrate is used, for example, in the manufacturing process of a semiconductor or semiconductor device. Any known coating apparatus can be used as the coating apparatus. Examples of coating apparatus include dip coaters, slit coaters, spin coaters, spray coaters, and inkjet coating apparatuses.

[0084] <Heating device> The doping apparatus described above includes a heating device for heating the semiconductor substrate coated with the adjusted water. Examples of heating devices include a hot plate, oven, infrared heater, induction heating device, dielectric heating device, lamp annealing device, and microwave heating device. The coating apparatus and the heating apparatus may be integrated into a single apparatus, or they may be provided as separate apparatuses. In the latter case, the semiconductor substrate to which the adjusted water has been coated in the coating apparatus is transferred to the heating apparatus.

[0085] <Example of a doping treatment device> The embodiment of the doping apparatus described above will be explained in detail below with reference to the drawings. Figures 1 to 4 are block diagrams that schematically represent the doping processing device described above.

[0086] The manufacturing apparatus 1 in Figure 1 comprises a transfer line L1 for the water to be treated W, such as ultrapure water, a dopant element concentration adjustment device 10, a pH adjustment device 50, an impurity component removal device 20, and a water quality monitoring device 30. The transfer line L1 connects the concentration adjustment device 10 and the pH adjustment device 50, the pH adjustment device 50 and the removal device 20, and the removal device 20 and the monitoring device 30. The manufacturing apparatus 1 in Figure 1 is equipped with a concentration adjustment device 10, a pH adjustment device 50, a removal device 20, and a monitoring device 30 in that order, from upstream to downstream of the transfer line L1 through which the water to be treated W flows. The produced adjusted water is sent to the use point (UP) via the transfer line L2. As a modified example of the manufacturing apparatus 1 in Figure 1, there is a manufacturing apparatus equipped with a concentration adjustment device 10, a removal device 20, a pH adjustment device 50, and a monitoring device 30 in that order, from upstream to downstream of the transfer line L1. The Use Point (UP) includes a water coating device and a semiconductor substrate heating device.

[0087] The manufacturing apparatus 1 in Figure 2 comprises a transfer line L1 for the water to be treated W, such as ultrapure water, a dopant element concentration adjustment device 10, a pH adjustment device 50, a water quality monitoring device 30, and an impurity component removal device 20. The transfer line L1 connects the concentration adjustment device 10 and the pH adjustment device 50, the pH adjustment device 50 and the water quality monitoring device 30, and the water quality monitoring device 30 and the removal device 20. The manufacturing apparatus 1 in Figure 2 is equipped with a concentration adjustment device 10, a pH adjustment device 50, a water quality monitoring device 30, and a removal device 20 in that order, from upstream to downstream of the transfer line L1 through which the water to be treated W flows. The produced adjusted water is sent to the use point (UP) via the transfer line L2. As a modified example of the manufacturing apparatus 1 in Figure 2, there is a manufacturing apparatus equipped with a concentration adjustment device 10, a water quality monitoring device 30, a removal device 20, and a pH adjustment device 50 in that order, from upstream to downstream of the transfer line L1.

[0088] The dopant element concentration adjustment device 10 in Figures 1 and 2 comprises a tank 12 containing a concentration adjusting agent containing the dopant component, and a supply line 14L connecting the tank 12 and the transfer line L1. It may further include a pump (not shown) located on the supply line 14L.

[0089] The manufacturing apparatus 1 in Figure 3 comprises a transfer line L1 for the water to be treated W, such as ultrapure water, a dopant element concentration adjustment device 10, a pH adjustment device 50, and a water quality monitoring device 30. The transfer line L1 connects the concentration adjustment device 10 and the pH adjustment device 50, and connects the pH adjustment device 50 to the water quality monitoring device 30. The manufacturing apparatus 1 in Figure 3 is equipped with a concentration adjustment device 10, a pH adjustment device 50, and a water quality monitoring device 30 in that order, from upstream to downstream of the transfer line L1 through which the water to be treated W flows. The manufactured adjusted water is sent to the use point (UP) via the transfer line L2.

[0090] The dopant element concentration adjustment device 10 in Figure 3 comprises a tank 12 containing a concentration adjustment agent containing the dopant component, an impurity component removal device 16, and a supply line 14L connecting the tank 12, the removal device 16, and the transfer line L1.

[0091] The manufacturing apparatus 1 in Figure 4 is equipped with a hydrogen peroxide removal device 90, a pH adjustment device 50, an ORP adjustment device 60, a degassing device 70, and a gas dissolution membrane device 80 in this order on the transfer line L1. Ultrapure water, which is the raw material water flowing through the transfer line L1, passes through the hydrogen peroxide removal device 90 to remove hydrogen peroxide, passes through the pH adjustment device 50 to become pH-adjusted water, the pH-adjusted water passes through the ORP adjustment device 60 to adjust the ORP, is degassed by passing through the degassing device 70, and the degassed pH-adjusted water passes through the gas dissolution membrane device 80 to become adjusted water. In the manufacturing apparatus 1 in Figure 4, the position of the water quality monitoring device 30 for measuring the concentration of dopant elements is not particularly limited as long as it is downstream of the concentration adjustment device 10.

[0092] The manufacturing apparatus 1 in Figure 4 may be equipped with a concentration adjustment device 10 at position A and a removal device 20 at positions B, C, D, E, or F; or it may be equipped with a concentration adjustment device 10 at position A or B and a removal device 20 at position C, D, E, or F; or it may be equipped with a concentration adjustment device 10 at position A, B, or C and a removal device 20 at position D, E, or F; or it may be equipped with a concentration adjustment device 10 at position A, B, C, or D and a removal device 20 at position E or F; or it may be equipped with a concentration adjustment device 10 at position A, B, C, D, or E and a removal device 20 at position F. The manufacturing apparatus 1 in Figure 4 may also include a dopant element concentration adjustment device 10, which is equipped with an impurity component removal device 16 at positions A, B, C, D, E, or F.

[0093] The manufacturing apparatus 1 in Figure 4 does not necessarily have to include at least one device selected from the group consisting of a hydrogen peroxide removal device 90, an ORP adjustment device 60, a degassing device 70, and a gas dissolution membrane type device 80.

[0094] In Figures 1 to 4, the control device 40 controls the amount or supply rate of the concentration adjusting agent added in the concentration adjusting device 10 and the amount or supply rate of the pH adjusting agent added in the pH adjusting device 50, based on the water quality obtained from the water quality monitoring device 30 (for example, the concentration of the dopant element, the concentration of the active ingredient of the pH adjusting agent, and the pH). In Figure 4, the control device 40 controls the amount or supply rate of the ORP adjusting agent added in the ORP adjusting device 60 and the inert gas added in the gas dissolution membrane type device 80, based on the water quality obtained from the water quality monitoring device 30.

[0095] Although the doping apparatus of this disclosure has been described above based on the above embodiments with reference to the attached drawings, the doping apparatus of this disclosure is not limited to the above embodiments and various modifications can be made.

[0096] [Method for doping semiconductor substrates] The semiconductor substrate doping method of this disclosure comprises the steps of: preparing adjusted water with a pH of 2 or higher and an adjusted concentration of dopant elements (hereinafter also referred to as the "preparation step"); applying the adjusted water to a semiconductor substrate (hereinafter also referred to as the "application step"); and heating the semiconductor substrate to which the adjusted water has been applied (hereinafter also referred to as the "heating step").

[0097] <Preparation process> The above preparation process is: The process involves adding a concentration adjusting agent containing a dopant component to the water to be treated, while controlling the amount added (hereinafter also referred to as the "addition process"), A step to adjust the pH of the water to be treated before or after adding the concentration adjusting agent (hereinafter also referred to as the "pH adjustment step"), It has.

[0098] In one embodiment, the above preparation step further includes a step of measuring the concentration of dopant elements in the treated water or adjusted water to which the concentration adjusting agent has been added (hereinafter also referred to as the "water quality monitoring step").

[0099] In one embodiment, the preparation step further comprises a step of selectively removing at least a portion of impurity components different from the dopant components from the water to be treated, which may contain the concentration adjusting agent (hereinafter also referred to as the "removal step"), or The above addition step further comprises a step (removal step) of selectively removing at least a portion of impurity components different from the dopant component from the concentration adjusting agent.

[0100] Through the above preparation process, the concentration of the dopant element is adjusted, and in one embodiment, adjusted water with a reduced content of impurity components can be produced. This adjusted water can be used for coating a semiconductor substrate in the manufacturing process of a semiconductor or semiconductor device.

[0101] In the addition step, a concentration adjusting agent containing a dopant component is added to the water to be treated, such as ultrapure water. Here, it is desirable to add the concentration adjusting agent so that the concentration of the dopant element in the adjusted water is preferably 100,000 mg / L or less, more preferably 0.1 to 50,000 mg / L, even more preferably 0.5 to 20,000 mg / L, and particularly preferably 1 to 13,000 mg / L.

[0102] In the pH adjustment step, in one embodiment, the pH of the water to be treated is adjusted so that the pH of the adjusted water is 2 or higher, preferably 3 to 11, more preferably 5 to 10, and even more preferably 7 to 10. In the pH adjustment step, in one embodiment, the pH of the water to be treated is adjusted to 2 or higher, preferably 3 to 11, more preferably 5 to 10, and even more preferably 7 to 10, by adding a pH adjusting agent to the water to be treated, etc. Adjusted water with such a pH has excellent diffusivity of dopant elements in semiconductor substrates, and by using this adjusted water, semiconductors or semiconductor devices with appropriate conductivity can be manufactured.

[0103] In the removal step, at least a portion of impurity components different from the dopant components are selectively removed from the water to be treated, which may contain a concentration adjusting agent, or from the concentration adjusting agent. Here, it is desirable to remove the impurity components so that the concentration of impurity components in the water to be treated or the concentration adjusting agent is preferably 1 μg / L or less, more preferably 0.1 μg / L or less, even more preferably 0.01 μg / L or less, and particularly preferably 0.001 μg / L or less.

[0104] In the water quality monitoring process, the water quality (e.g., concentration of dopant elements, concentration of active ingredients of pH adjusters, pH) of the treated water to which the concentration adjuster has been added, or the resulting adjusted water, is measured to monitor whether or not it has the desired water quality. To ensure that the adjusted water has the desired water quality, a control device is used to control at least one selected from the group consisting of the amount or supply rate of the concentration adjuster added in the addition process and the amount or supply rate of the pH adjuster added in the pH adjustment process.

[0105] The above manufacturing method may further include at least one step selected from the group consisting of a hydrogen peroxide removal step to remove hydrogen peroxide from the water to be treated, an ORP adjustment step to adjust the oxidation-reduction potential (ORP) of the water to be treated, a degassing step to remove gas from the water to be treated, and a gas dissolution step to dissolve an inert gas into the water to be treated.

[0106] Details of the above preparation process and the conditions for each process can be applied as described in the <Prepared Water Production Equipment> section above, and are therefore omitted from this section. The above preparation process can be carried out, for example, using the above-mentioned manufacturing apparatus.

[0107] The prepared water produced by the above manufacturing apparatus or preparation process is used, for example, to coat a semiconductor substrate in the manufacturing process of a semiconductor or semiconductor device, specifically for liquid doping the semiconductor substrate. For example, after applying the prepared water to the surface of the semiconductor substrate, the dopant contained in the prepared water is diffused into the semiconductor substrate by heat treatment.

[0108] <Coating process> In the coating process, the prepared water is applied to the semiconductor substrate. Known coating methods can be used, such as dip coating, slit coating, spin coating, spray coating, and inkjet coating. The temperature of the prepared water to be applied is preferably 10 to 90°C, more preferably 20 to 45°C, and in the case of dip coating in which the semiconductor substrate is immersed in the prepared water, the immersion time is preferably 0.5 to 60 minutes, more preferably 1 to 45 minutes.

[0109] As the semiconductor substrate, various substrates that have conventionally been used as targets for dopant diffusion can be used without particular limitations. For example, silicon substrates such as silicon wafers can be used as semiconductor substrates. The material of the surface of the semiconductor substrate to which the above-mentioned adjusted water is applied is not particularly limited, but examples include Si, SiO2, SiCN, SiN, and SiC.

[0110] <Heating process> In the heating step, the semiconductor substrate coated with the prepared water is heated. The heating step allows the dopant elements contained in the prepared water to diffuse well into the semiconductor substrate.

[0111] The heating temperature in the heating step is preferably 200 to 1000°C, more preferably 300 to 900°C, even more preferably 400 to 800°C, and particularly preferably 400 to 700°C, from the viewpoint of the diffusibility of the dopant element and the thermal budget. The heating time in the heating step is preferably 1 minute to 10 hours, more preferably 3 minutes to 5 hours, and even more preferably 5 minutes to 60 minutes, from the viewpoint of the above.

[0112] [Manufacturing methods for semiconductors or semiconductor devices] A semiconductor or semiconductor device can be manufactured by a manufacturing method that includes a step of doping a semiconductor substrate using the doping method described above. Other known steps can be used in addition to the doping step. Examples of semiconductor devices include transistors, diodes, and solar cells.

[0113] [Example of form] This disclosure relates, for example, to the following [1] to

[14] . [1] A method for doping a semiconductor substrate, comprising: a preparation step of preparing adjusted water having a pH of 2 or higher and an adjusted concentration of dopant elements; a coating step of coating the adjusted water onto a semiconductor substrate; and a heating step of heating the semiconductor substrate coated with the adjusted water, wherein the preparation step of the adjusted water comprises: an addition step of adding a concentration adjusting agent containing a dopant component to the water to be treated, with the amount of addition controlled; and a pH adjustment step of adjusting the pH of the water to be treated before or after the addition of the concentration adjusting agent. [2] The doping method for a semiconductor substrate according to [1], wherein the preparation step further comprises a step of selectively removing at least a portion of impurity components different from the dopant component from the water to be treated, which may contain the concentration adjusting agent, or the addition step further comprises a step of selectively removing at least a portion of impurity components different from the dopant component from the concentration adjusting agent. [3] The doping method for a semiconductor substrate according to [2], wherein the concentration of the impurity component in the treated water or the concentration adjusting agent after removal is 1 μg / L or less. [4] The method for doping a semiconductor substrate according to any one of [1] to [3], wherein the concentration of the dopant element in the adjusted water is 100,000 mg / L or less. [5] The method for doping a semiconductor substrate according to any one of [1] to [4], wherein the concentration adjusting agent is an aqueous solution containing the dopant component. [6] The method for doping a semiconductor substrate according to [5], wherein the aqueous solution contains at least one selected from the group consisting of compounds containing an n-type dopant and compounds containing a p-type dopant. [7] A method for manufacturing a semiconductor or semiconductor device, comprising the step of doping a semiconductor substrate using the semiconductor substrate doping method described in any of [1] to [6] above. [8] A semiconductor substrate doping apparatus comprising: a production apparatus for adjusted water having a pH of 2 or higher and an adjusted concentration of dopant elements; a coating apparatus for coating a semiconductor substrate with the adjusted water; and a heating apparatus for heating the semiconductor substrate coated with the adjusted water, wherein the production apparatus comprises: a dopant element concentration adjustment apparatus for adding a concentration adjusting agent containing a dopant component to the water to be treated, with control over the amount added; and a pH adjustment apparatus for adjusting the pH of the water to be treated before or after the addition of the concentration adjusting agent. [9] The semiconductor substrate doping apparatus according to [8], wherein the manufacturing apparatus comprises an impurity component removal device for selectively removing at least a portion of impurity components different from the dopant components from the water to be treated or the concentration adjusting agent to which the concentration adjusting agent may be added.

[10] The semiconductor substrate doping apparatus according to [9], wherein the removal device has at least one selected from the group consisting of an ion exchange resin, an ion exchange membrane, a nanofiltration membrane, and a reverse osmosis membrane.

[11] The semiconductor substrate doping apparatus according to [9] or

[10] , wherein the removal device is located upstream or downstream of the dopant element concentration adjustment device on the transfer line of the water to be treated.

[12] The doping apparatus for a semiconductor substrate according to any one of [9] to

[11] , wherein the concentration adjustment device has the removal device.

[13] The semiconductor substrate doping apparatus according to any one of [8] to

[12] , further comprising: a water quality monitoring device for measuring the concentration of the dopant element in the water to be treated or the adjusted water to which the concentration adjusting agent has been added; and a control device for controlling the amount of the concentration adjusting agent added in the concentration adjusting device based on the concentration of the dopant element measured by the water quality monitoring device.

[14] The semiconductor substrate doping apparatus according to any one of [8] to

[13] , wherein the manufacturing apparatus further comprises an oxidation-reduction potential adjusting device for adjusting the oxidation-reduction potential of the water to be treated before or after the addition of the concentration adjusting agent. [Examples]

[0114] The semiconductor substrate doping method described herein will be explained based on examples. The semiconductor substrate doping method described herein is not limited to the following examples.

[0115] A 4% by mass boric acid aqueous solution, a 4% by mass arsenite aqueous solution, and a 50% by mass phosphoric acid aqueous solution were prepared, respectively. In the following examples, a doping apparatus equipped with the manufacturing apparatus 1 shown in Figure 1 was used. The dopant element concentration adjustment apparatus 10 comprises a tank containing the boric acid aqueous solution, a tank containing the arsenite aqueous solution, and a tank containing the phosphoric acid aqueous solution. The impurity component removal apparatus 20 is equipped with a cation exchange resin (product name KR-FC, manufactured by Kurita Water Industries Ltd.).

[0116] [Example 1] Using the manufacturing apparatus 1 shown in Figure 1, the following adjusted water was produced as described below. To ultrapure water, a mixture was prepared by adding boric acid aqueous solution, arsenous acid aqueous solution, and phosphoric acid aqueous solution, respectively, in amounts such that the concentrations of boric acid, arsenous acid, and phosphoric acid in the adjusted water reached the values ​​shown in Table 1, using a concentration adjustment device 10. Next, a pH adjusting agent (ammonia aqueous solution) was added using a pH adjustment device 50. Then, the pH-adjusted mixture was passed through a removal device 20 equipped with a cation exchange resin (product name KR-FC). In this way, adjusted water 1 with concentrations of boric acid, arsenous acid, and phosphoric acid of 1% by mass (10,000 ppm) each was prepared.

[0117] pH was measured using a pH meter (manufactured by Horiba). The dopant amounts (amounts of P, B, and As) in the adjusted water were measured using an inductively coupled plasma mass spectrometer (ICP-MS, manufactured by Agilent). Criteria for evaluating the amount of dopant in adjusted water Small: The content of elements P, B, and As is less than 1 mg / L. Medium: The content of elements P, B, and As is 1 to 10,000 mg / L. Large: The content of elements P, B, and As exceeds 10,000 mg / L. The above evaluation of content is an evaluation for each of the elements listed above.

[0118] The amount of metallic elements in the adjusted water was measured using an inductively coupled plasma mass spectrometer (ICP-MS, manufactured by Agilent). Evaluation criteria for the amount of metallic elements in treated water Small: The content of elements Na, Ca, and Fe is less than 1 ng / L. Medium: The content of elements Na, Ca, and Fe is 1 to 1000 ng / L. Large: The content of elements Na, Ca, and Fe exceeds 1000 ng / L. The above evaluation of content is an evaluation for each of the elements listed above.

[0119] The prepared water was filled into a batch tank, and the silicon wafers were immersed in the prepared water at 25°C for 10 minutes, after which they were removed from the water. The immersed silicon wafers were then annealed at 700°C for 20 minutes. To determine the amount of doped ions on the silicon wafers, the volume resistivity was calculated using a 4-probe sheet resistivity analyzer (SEMiLAb, FPP1000). The volume resistivity was evaluated according to the following criteria. The results are shown in Table 1.

[0120] Evaluation criteria for volume resistivity ◎: 1.0 × 10 -4 ~1.0×10 0 Ωcm ○: 1.0 × 10 0 Ωcm super 1.0×10 5 Ωcm or less △: 1.0 × 10 -4 Less than Ωcm ×: 1.0 × 10 5 Ωcm super

[0121] The diffusion depth of each element in the silicon wafer after annealing was determined by secondary ion mass spectrometry (SIMS analysis, Cameca). Criteria for evaluating diffusion depth ◎:50nm or more ○: 25nm or more, less than 50nm △: Greater than 5nm, less than 25nm ×: 5nm or less

[0122] [Examples 2-5, Comparative Example 1] Adjusted waters 2-5 and 7 were prepared in the same manner as in Example 1, except that the type and amount of boric acid aqueous solution and pH adjuster were adjusted, and the concentration or pH of each component was changed as shown in Table 1. The procedure was carried out in the same manner as in Example 1, except that these adjusted waters were used.

[0123] [Example 6] Using the manufacturing apparatus 1 shown in Figure 1 (but without the removal apparatus 20), the following adjusted water was produced as follows: To ultrapure water, an amount of phosphoric acid aqueous solution was added in the concentration adjustment apparatus 10 so that the concentration of phosphoric acid in the adjusted water was the value shown in Table 1. Then, a pH adjusting agent (ammonia aqueous solution) was added in the pH adjustment apparatus 50 to adjust the pH to the value shown in Table 1, thereby preparing adjusted water 6. The procedure was the same as in Example 1, except that adjusted water 6 was used.

[0124] [Table 1] [Explanation of Symbols]

[0125] 1 ... Equipment for producing adjusted water 10 ... Dopant element concentration adjustment device 12... Tank containing concentration adjusting agent 14L… Supply line 16, 20 ... Device for removing impurities 30…Water quality monitoring device 40 ... control device 50...pH adjustment device 60…ORP adjustment device 70 ... Degassing device 80 ...Gas dissolution membrane type apparatus 90... Hydrogen peroxide removal device W... water to be treated, such as ultrapure water. L1, L2...transfer lines UP... Youth Points

Claims

1. A preparation step for preparing adjusted water with a pH of 2 or higher, in which the concentration of dopant elements has been adjusted, A coating step of applying the adjusted water to a semiconductor substrate, A heating step of heating the semiconductor substrate to which the adjusted water has been applied, A method for doping a semiconductor substrate, comprising: The preparation step for the adjusted water comprises an addition step of adding a concentration adjusting agent containing a dopant component to the water to be treated, with the amount of addition controlled, and a pH adjustment step of adjusting the pH of the water to be treated before or after the addition of the concentration adjusting agent. A method for doping semiconductor substrates.

2. The preparation step further comprises a step of selectively removing at least a portion of impurity components different from the dopant component from the water to be treated, which may contain the concentration adjusting agent, or The addition step further includes a step of selectively removing at least a portion of impurity components different from the dopant component from the concentration adjusting agent. The method for doping a semiconductor substrate according to claim 1.

3. The doping method for a semiconductor substrate according to claim 2, wherein the concentration of the impurity component in the treated water or the concentration adjusting agent after removal is 1 μg / L or less.

4. The method for doping a semiconductor substrate according to claim 1, wherein the concentration of the dopant element in the adjusted water is 100,000 mg / L or less.

5. The method for doping a semiconductor substrate according to claim 1, wherein the concentration adjusting agent is an aqueous solution containing the dopant component.

6. The method for doping a semiconductor substrate according to claim 5, wherein the aqueous solution is an aqueous solution containing at least one selected from the group consisting of compounds containing an n-type dopant and compounds containing a p-type dopant.

7. A method for manufacturing a semiconductor or semiconductor device, comprising the step of doping a semiconductor substrate using the semiconductor substrate doping method described in any one of claims 1 to 6.

8. A device for producing adjusted water with a pH of 2 or higher, in which the concentration of dopant elements has been adjusted, A coating apparatus for applying the adjusted water to a semiconductor substrate, A heating device for heating the semiconductor substrate to which the adjusted water has been applied, A semiconductor substrate doping apparatus comprising, The manufacturing apparatus comprises a dopant element concentration adjustment device that adds a concentration adjusting agent containing a dopant component to the water to be treated, while controlling the amount added, and a pH adjustment device that adjusts the pH of the water to be treated before or after the addition of the concentration adjusting agent. A doping apparatus for semiconductor substrates.

9. The semiconductor substrate doping apparatus according to claim 8, wherein the manufacturing apparatus comprises an impurity component removal device for selectively removing at least a portion of impurity components different from the dopant component from the water to be treated or the concentration adjusting agent to which the concentration adjusting agent may be added.

10. The semiconductor substrate doping apparatus according to claim 9, wherein the removal device comprises at least one selected from the group consisting of an ion exchange resin, an ion exchange membrane, a nanofiltration membrane, and a reverse osmosis membrane.

11. The semiconductor substrate doping apparatus according to claim 9, wherein the removal device is located upstream or downstream of the dopant element concentration adjustment device on the transfer line of the water to be treated.

12. The doping apparatus for a semiconductor substrate according to claim 9, wherein the concentration adjustment device has the removal device.

13. The aforementioned manufacturing apparatus A water quality monitoring device for measuring the concentration of the dopant element in the treated water or adjusted water to which the concentration adjusting agent has been added, A control device that controls the amount of the concentration adjusting agent added to the concentration adjusting device based on the concentration of the dopant element measured by the water quality monitoring device, The semiconductor substrate doping apparatus according to claim 8, further comprising:

14. The semiconductor substrate doping apparatus according to claim 8, wherein the manufacturing apparatus further comprises an oxidation-reduction potential adjusting device for adjusting the oxidation-reduction potential of the water to be treated before or after the addition of the concentration adjusting agent.

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