Substrate processing method and substrate processing apparatus

Abstract

The substrate processing method of the present invention includes: a solution step, which involves supplying an acidic solution to the main surface of the substrate W; an acidic rinsing step, which involves supplying an acidic rinsing solution with a pH value adjusted to below that of the acidic solution to the main surface of the substrate to replace the acidic solution on the main surface of the substrate; and a neutral rinsing step, which involves supplying a neutral rinsing solution with a pH value higher than that of the acidic rinsing solution to the main surface of the substrate to replace the acidic rinsing solution on the main surface of the substrate. In one embodiment, the substrate has metallic contaminants on its main surface, and the solution step is a step of removing the metallic contaminants from the main surface of the substrate by means of an acidic solution. The acidic solution used in the solution step may also be a recycled solution with a history of being used to remove metallic contaminants.

Description

Technical Field

[0001] This invention relates to a substrate processing method and a substrate processing apparatus. Substrates that can be processed include, for example, semiconductor wafers, substrates for FPDs (Flat Panel Displays) such as liquid crystal display devices and organic EL (Electroluminescence) display devices, optical disc substrates, magnetic disk substrates, magneto-optical disk substrates, photomask substrates, ceramic substrates, and solar cell substrates. Prior Technology

[0002] In the manufacturing process of semiconductor devices, cleaning of the semiconductor substrate (semiconductor wafer) is essential. Various cleaning solutions are used depending on the contaminants to be removed from the substrate. For the removal of one typical contaminant—metallic contaminants—acidic solutions can be used; a specific example is a mixture of hydrochloric acid, hydrogen peroxide, and water. A typical hydrochloric acid-hydrogen peroxide-water mixture is SC2, generated by mixing hydrochloric acid, hydrogen peroxide, and deionized water (DIW) in a specified mixing ratio. Cleaning treatments for removing metallic contaminants may include, for example, supplying the substrate with SC2 and then rinsing it with a rinsing solution such as DIW to replace the SC2 (see Patent Document 1). [Previous Technical Documents] [Patent Literature]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2008-277576 Summary of the Invention

[0004] [The problem the invention aims to solve] To reduce environmental burden, there has been a persistent desire to decrease the amount of chemical solutions used. Consequently, reducing the amount of chemical solutions used naturally lowers their cost, as does the cost of waste disposal. One strategy for reducing chemical solution usage is to recycle and reuse the solutions after they have been used to treat substrates. However, solutions used to remove metal contaminants contain metal substances (more specifically, metal ions), so recycling and reusing them for substrate treatment could potentially turn them into a source of metal contamination.

[0005] For example, the following method can be considered: divide the chemical treatment into a first half and a second half. The first half uses the chemical solution recovered after treating the substrate (recovered chemical solution), while the second half uses unused chemical solution (fresh solution). The fresh solution supplied to the substrate in the second half replaces the recovered chemical solution supplied to the substrate in the first half, thus flushing away metal contaminants from the substrate. This achieves the same metal contaminant removal performance as when performing the entire chemical treatment with fresh solution, while reducing the amount of chemical solution used.

[0006] However, if the use of fresh solution can be reduced in the latter half of the treatment, the amount of solution used can be further reduced, which is better.

[0007] Therefore, one embodiment of the present invention provides a substrate processing method and substrate processing apparatus that can effectively reduce the amount of pharmaceutical solution used (especially the amount of acidic pharmaceutical solution used). [Technical means to solve the problem]

[0008] One embodiment of the present invention provides a substrate processing method and a substrate processing apparatus having the following illustratively listed features.

[0009] 1. A substrate processing method, comprising: The chemical solution step involves supplying an acidic chemical solution to the main surface of the substrate; The acidic rinsing step involves supplying an acidic rinsing solution, the pH of which has been adjusted to be below the pH (hydrogen ion index) of the acidic solution, to the main surface of the substrate to replace the acidic solution on the main surface of the substrate; and The neutral rinsing step involves supplying a neutral rinsing solution with a pH value higher than that of the acidic rinsing solution to the main surface of the substrate to replace the acidic rinsing solution on the main surface of the substrate.

[0010] 2. The substrate processing method of item 1, wherein the substrate has metallic contaminants on the main surface. The above-mentioned chemical solution step is a step in which the above-mentioned metallic contaminants are removed from the main surface of the above-mentioned substrate by means of the above-mentioned acidic chemical solution, and The aforementioned substrate processing method further includes a solution recovery step for recovering the aforementioned acidic solution, wherein the acidic solution has been used in the aforementioned solution recovery step and contains the aforementioned metallic contaminants removed from the main surface of the substrate; The acidic solution supplied to the substrate in the above-mentioned solution step includes the acidic solution containing the above-mentioned metal contaminants that was recovered in the above-mentioned solution recovery step.

[0011] Typically, the acidic solution used in the solution step for the first substrate will be recovered by the aforementioned solution recovery step, and the recovered acidic solution will be used in the solution step for the second substrate (a substrate different from the first substrate).

[0012] Typically, metallic contaminants are contained in acidic solutions in the form of metal ions and are removed from the substrate. The acidic solutions containing the metallic contaminants (metal ions) are then recycled.

[0013] 3. The substrate processing method of item 1 or 2, wherein the pH value of the acidic solution is 0.1 or higher and 3 or lower.

[0014] 4. The substrate processing method of any one of items 1 to 3, wherein the acidic rinsing solution comprises one or more of carbonated water, electrolyzed water, and water with added acid.

[0015] Carbonated water can also be a carbonated liquid containing substances other than carbonic acid and water. Electrolyzed water, obtained by the electrolysis of water, can also contain substances other than water. Similarly, water with added acid can be an acidic liquid containing substances other than acid and water. Examples of acids include hydrochloric acid and nitric acid. In this case, the water with added acid is dilute hydrochloric acid or dilute nitric acid, and if other substances are added, it can be a hydrochloric acid-containing liquid or a nitric acid-containing liquid.

[0016] 5. The substrate processing method according to any one of items 1 to 4 further includes: The pH value acquisition step involves acquiring the pH value of the acidic solution used in the above-mentioned solution preparation step; and The acidic rinsing solution preparation step involves preparing an acidic rinsing solution with a pH value below that detected in the pH value acquisition step described above; and The above-mentioned acidic rinsing step involves supplying the acidic rinsing solution prepared in the above-mentioned acidic rinsing solution preparation step to the main surface of the substrate.

[0017] 6. The substrate processing method of item 5, wherein the pH value acquisition step includes a step of detecting the pH value of the acidic solution used in the above-mentioned solution step by means of a pH value sensor.

[0018] If the pH value of the acidic solution is known, then pH testing is no longer necessary, and the pH value acquisition step can also be the same as the step of acquiring the known value (known data).

[0019] 7. The substrate processing method as described in item 5 or 6, wherein the above-mentioned acidic rinsing solution preparation step includes: The target pH setting step is based on the pH value obtained from the pH value acquisition step described above; and The mixing step involves mixing the neutral rinsing solution and the acid in a mixing ratio to generate the acidic rinsing solution, wherein the mixing ratio is set based on the target pH value set in the target pH value setting step.

[0020] The above mixing step can also be an in-pipe mixing step, in which the neutral rinsing solution and acid are mixed in the piping. Specifically, the neutral rinsing solution and acid are supplied to a common piping at a flow rate corresponding to the above mixing ratio, thereby generating an acidic rinsing solution with the target pH value through in-pipe mixing. For example, the neutral rinsing solution and acid can also be mixed in the manifold of a multi-way valve (an example of a common piping).

[0021] The above mixing step can also be an in-tank mixing step, in which the neutral rinsing solution and acid are mixed in the tank.

[0022] 8. The substrate processing method of any one of items 1 to 7, wherein the above-mentioned chemical solution step involves supplying an acidic chemical solution containing metal ions to the main surface of the substrate.

[0023] 9. The substrate processing method of any one of items 1 to 8 further includes a drying step of removing the neutral rinsing liquid from the main surface of the substrate and drying the main surface of the substrate.

[0024] The drying step described above can also be a rotary drying step in which the substrate is rotated around a rotation axis passing through the main surface of the substrate to remove the neutral rinsing solution.

[0025] 10. A substrate processing method, comprising: The first chemical solution step involves supplying a first acidic chemical solution to the main surface of a first substrate that has metallic contaminants, thereby removing the metallic contaminants from the main surface of the first substrate using the first acidic chemical solution. The first neutral rinsing step involves supplying a neutral rinsing solution with a pH value higher than that of the first acidic solution to the main surface of the first substrate to replace the first acidic solution on the main surface of the first substrate. The first chemical solution recovery step (first chemical solution recovery step) recovers the first acidic chemical solution, which has been used in the first chemical solution step and contains the aforementioned metallic contaminants removed from the main surface of the first substrate; The second chemical solution step involves supplying a second acidic chemical solution, comprising the first acidic chemical solution recovered in the aforementioned chemical solution recovery step, to the main surface of the second substrate; The acidic rinsing step involves supplying an acidic rinsing solution, the pH of which has been adjusted to be below that of the second acidic solution, to the main surface of the second substrate to replace the second acidic solution on the main surface of the second substrate; and The second neutral rinsing step involves supplying a second neutral rinsing solution with a pH value higher than that of the acidic rinsing solution to the main surface of the second substrate to replace the acidic rinsing solution on the main surface of the second substrate.

[0026] The above-described substrate processing method may further include a second chemical recovery step, which recovers the second acidic chemical solution that has been used in the second chemical solution step.

[0027] The second substrate may also have metallic contaminants on its main surface. Furthermore, the second chemical solution step may also be a step of supplying the second acidic chemical solution to the main surface of the second substrate, thereby removing the metallic contaminants from the main surface of the second substrate using the second acidic chemical solution.

[0028] The above-described substrate processing method may also include, after the first neutral rinsing step, a first drying step to remove the first neutral rinsing solution from the main surface of the first substrate and dry the main surface of the first substrate.

[0029] The above-described substrate processing method may also include, after the above-described second neutral rinsing step, a second drying step to remove the above-described second neutral rinsing solution from the main surface of the second substrate and dry the main surface of the second substrate.

[0030] The first chemical solution step, the first neutral rinsing step, and the first chemical solution recovery step can also be repeated on multiple first substrates (and the first drying step may also be added if necessary).

[0031] Similarly, the above-mentioned second chemical solution step, the above-mentioned acidic rinsing step, and the above-mentioned second neutral rinsing step can be repeated on multiple second substrates (if necessary, the above-mentioned second drying step and / or the above-mentioned second chemical solution recovery step may also be added).

[0032] 11. A substrate processing apparatus, comprising: A substrate holding unit that holds the substrate. An acidic solution supply unit supplies an acidic solution to the main surface of the substrate held in the aforementioned substrate holding unit; An acidic rinsing solution supply unit supplies an acidic rinsing solution, the pH of which has been adjusted to be below the pH (hydrogen ion index) of the acidic solution, to the main surface of the substrate held in the substrate holding unit. A neutral rinsing solution supply unit supplies a neutral rinsing solution with a pH value higher than that of the acidic rinsing solution to the main surface of the substrate held in the substrate holding unit; and The drying unit dries the main surface of the substrate held in the substrate holding unit.

[0033] 12. The substrate processing apparatus of item 11, further comprising a controller for controlling the acidic solution supply unit, the acidic rinsing solution supply unit, the neutral rinsing solution supply unit, and the drying unit, and The controller is programmed to perform the following steps: a chemical solution step, in which the acidic chemical solution is supplied to the main surface of the substrate by the acidic chemical solution supply unit; an acidic rinsing step, in which the acidic rinsing solution is supplied to the main surface of the substrate by the acidic rinsing solution supply unit to replace the acidic chemical solution on the main surface of the substrate; a neutral rinsing step, in which the neutral rinsing solution is supplied to the main surface of the substrate by the neutral rinsing solution supply unit to replace the acidic rinsing solution on the main surface of the substrate; and a drying step, in which the neutral rinsing solution on the main surface of the substrate is removed by the drying unit to dry the main surface of the substrate.

[0034] 13. The substrate processing apparatus of item 11 or 12, wherein the acidic solution supply unit includes a recovery solution supply unit. The aforementioned recovery liquid supply unit includes a recovery tank, which supplies the aforementioned acidic liquid that has been recovered to the recovery tank to the substrate (typically another substrate) held in the aforementioned substrate holding unit. The recovery tank recovers and stores the acidic liquid supplied to the substrate held in the aforementioned substrate holding unit, and then discharges the acidic liquid outside the substrate.

[0035] 14. The substrate processing apparatus of item 13, wherein the acidic solution recycled to the recycling tank contains metallic contaminants (typically metallic contaminants originating from the substrate).

[0036] 15. The substrate processing apparatus of item 13 or 14, wherein the acidic solution supply unit includes a fresh solution supply unit. The aforementioned new liquid supply unit supplies the substrate held in the aforementioned substrate holding unit with an unused acidic liquid that has no history of being used to treat substrates.

[0037] 16. The substrate processing apparatus of item 15, further comprising a controller for controlling the aforementioned fresh liquid supply unit, the aforementioned recycled liquid supply unit, the aforementioned acidic rinsing liquid supply unit, the aforementioned neutral rinsing liquid supply unit, and the aforementioned drying unit, and The controller described above is programmed to perform the following steps: The first liquid treatment step involves supplying unused acidic liquid from the aforementioned new liquid supply unit to the main surface of the first substrate held in the aforementioned substrate holding unit; The first neutral rinsing step involves supplying the neutral rinsing solution to the main surface of the first substrate via the neutral rinsing solution supply unit to replace the acidic solution supplied to the main surface of the first substrate in the first chemical solution step. The first drying step involves removing the neutral rinsing solution supplied to the main surface of the first substrate by the aforementioned drying unit, thereby drying the main surface of the first substrate. The chemical solution recovery step involves recovering the acidic chemical solution removed from the main surface of the first substrate to the recovery tank. The acidic chemical solution has already been used in the first chemical solution step. The second chemical solution step involves supplying the acidic chemical solution recovered from the chemical solution recovery step and sent to the recovery tank to the main surface of the second substrate via the aforementioned recovery solution supply unit. The acid rinsing step involves supplying the acid rinsing solution to the main surface of the second substrate via the acid rinsing solution supply unit, thereby replacing the acid solution supplied to the main surface of the second substrate in the second chemical solution step. The second neutral rinsing step involves supplying neutral rinsing solution to the main surface of the second substrate via the neutral rinsing solution supply unit to replace the acidic rinsing solution supplied to the main surface of the second substrate in the acidic rinsing step; and The second drying step involves removing the neutral rinsing liquid supplied to the main surface of the second substrate by the drying unit, thereby drying the main surface of the second substrate.

[0038] 17. The substrate processing apparatus of any one of items 11 to 16, further comprising a pH value acquisition unit for acquiring the pH value of the acidic solution supplied by the aforementioned acidic solution supply unit, and The aforementioned acidic rinsing solution supply unit includes an acidic rinsing solution preparation unit for preparing an acidic rinsing solution with a pH value below that obtained by the aforementioned pH value acquisition unit.

[0039] 18. The substrate processing apparatus of item 17, wherein the pH value acquisition unit includes a pH value sensor for detecting the pH value of the acidic solution supplied by the acidic solution supply unit.

[0040] 19. The substrate processing apparatus of any one of items 11 to 18, wherein the acidic solution supply unit supplies an acidic solution containing metal ions to the main surface of the substrate.

[0041] 20. The substrate processing apparatus of any one of items 11 to 19, wherein the acidic solution supply unit supplies an acidic solution with a pH value of 0.1 or higher and 3 or lower.

[0042] 21. In addition to the above, the substrate processing apparatus assembly may also have one or more of the features described in relation to the substrate processing method.

[0043] The above-mentioned or other objects, features and effects of the present invention will become clear by referring to the description of the embodiments set forth below with reference to the accompanying drawings. Simple Explanation of the Diagram

[0044] Figure 1 is a diagram illustrating a substrate processing method according to one embodiment of the present invention. Figure 2 is a diagram used to illustrate the experiment used to verify the substrate processing in Figure 1. Figure 3A is a graph showing the evaluation results when a pure water rinsing step is applied (comparative example). Figure 3B is a graph showing the evaluation results when using an acidic rinsing solution with a pH of 4 for the acidic rinsing step (comparative example). Figure 3C is a graph showing the evaluation results of the acidic rinsing step (Example) when using an acidic rinsing solution with a pH of 0.1. Figure 4 illustrates the mechanism by which acidic rinsing inhibits the residue of metallic contaminants. Figure 5 is a schematic top view illustrating an example of the configuration of a substrate processing apparatus according to one embodiment of the present invention. Figure 6 is a schematic diagram illustrating the configuration of the processing unit in the aforementioned substrate processing apparatus. Figure 7 is a diagram illustrating an example of the configuration of a treatment fluid supply system. Figure 8 is a block diagram illustrating the electrical configuration of the substrate processing device. Figure 9 is a flowchart illustrating an example of substrate processing performed by a substrate processing apparatus. Figure 10 is a diagram illustrating another configuration example of a treatment fluid supply system. Implementation

[0045] Figure 1 is a diagram illustrating a substrate processing method according to one embodiment of the present invention. The substrate processing method includes: a solution step, in which an acidic solution is supplied to the main surface of a substrate W; an acidic rinsing step, in which an acidic rinsing solution is supplied to the main surface of the substrate W; and a neutral rinsing step, in which a neutral rinsing solution is supplied to the main surface of the substrate W. After the neutral rinsing step, a drying step is performed as needed, i.e., the neutral rinsing solution is removed from the main surface of the substrate W, thereby drying the main surface of the substrate W.

[0046] The acidic rinsing step involves replacing the acidic chemical solution supplied to the main surface of substrate W in the chemical solution step with an acidic rinsing solution. The acidic rinsing solution has its pH value adjusted to be below the pH value (hydrogen ion index) of the acidic chemical solution. The neutral rinsing step involves replacing the acidic rinsing solution supplied to the main surface of substrate W in the acidic rinsing step with a neutral rinsing solution. The neutral rinsing solution has a higher pH value than the acidic rinsing solution. The pH value of the neutral rinsing solution does not necessarily have to be 7; for example, it can be in the range of 4 or higher but below 10.

[0047] The acidic solution on the substrate W, which is replaced by an acidic rinsing solution, may also contain metallic contaminants. Typically, the metallic contaminants may be present in the acidic solution in the form of metal ions. The metallic contaminants may also originate from metallic materials present on the main surface of the substrate W. Furthermore, metallic contaminants may also be present in the acidic solution supplied to the main surface of the substrate W during the chemical treatment process.

[0048] For example, substrate W may also have metallic contaminants on its main surface, and the chemical solution step may be a step of removing the metallic contaminants from the main surface of substrate W using an acidic chemical solution. In this case, the main surface of substrate W before the acidic rinsing step contains the metallic contaminants removed from the main surface of substrate W. Furthermore, the chemical solution used in the chemical solution step (used chemical solution) can also be recycled and reused in subsequent chemical solution steps. That is, the acidic chemical solution used in the chemical solution step may also be an acidic chemical solution with a history of being used to remove metallic contaminants. In this case, the aforementioned acidic chemical solution with a history of use contains metallic contaminants, therefore, when this acidic chemical solution is reused in the chemical solution step, the chemical solution supplied to the main surface of substrate W contains metallic contaminants.

[0049] Typical examples of acidic solutions are hydrochloric acid-hydrogen peroxide-water mixtures (e.g., SC2) and sulfuric acid-hydrogen peroxide-water mixtures (SPM). Their pH values ​​are, for example, above 0.1 and below 3.

[0050] Acidic rinsing solutions with a pH value similar to or lower than that of such acidic solutions can be carbonated water, electrolyzed water, dilute hydrochloric acid, dilute nitric acid, or any combination thereof. Carbonated water may also contain carbonic acid and substances other than water. The pH value of carbonated water is in the range of approximately 4 to 5.6. Electrolyzed water is a liquid obtained by electrolyzing water and may also contain substances other than water. The pH value of electrolyzed water ranges from approximately 1.3 to 12.9. Dilute hydrochloric acid is an aqueous solution obtained by adding a trace amount of hydrochloric acid to water and may also contain hydrochloric acid and substances other than water. The pH value of dilute hydrochloric acid does not reach 7. Dilute nitric acid is an aqueous solution obtained by adding a trace amount of nitric acid to water and may also contain nitric acid and substances other than water. The pH value of dilute nitric acid does not reach 7. Hydrochloric acid and nitric acid are examples of acids; an acidic rinsing solution can be prepared by adding a trace amount of acid to water. One example of a neutral flushing solution in a water system is deionized water (DIW).

[0051] Neutral rinsing solutions are typically deionized water. In addition, carbonated water and electrolyzed water, which have a higher pH value than acidic rinsing solutions, can also be used as neutral rinsing solutions.

[0052] According to the substrate processing method of this embodiment, by performing an acidic rinsing step between the chemical solution step and the neutral rinsing step, the adsorption of metal impurities (typically metal ions) in the chemical solution on the main surface of the substrate W to the main surface of the substrate W can be suppressed, thereby efficiently removing metal impurities from the substrate W. By subsequently replacing the acidic rinsing solution with a neutral rinsing solution and drying the substrate W in the neutral rinsing step, metal impurities can be efficiently removed from the main surface of the substrate W, thereby achieving a high degree of substrate cleaning.

[0053] Furthermore, even if the solution supplied to the substrate W during the chemical solution process contains metallic impurities, the metallic impurities can be substantially prevented from remaining on the main surface of the substrate W by performing an acid rinsing step. Therefore, although a solution containing metallic impurities is used, substrate processing can be performed in a manner substantially equivalent to that when a solution without metallic impurities is used.

[0054] Therefore, by recycling the acidic solution used in the chemical solution step and reusing it in subsequent chemical solution steps for substrate treatment, the same substrate treatment as when using unused chemical solution (fresh solution) can be achieved. This reduces the amount of chemical solution used, thus alleviating environmental impact and reducing the cost of substrate treatment.

[0055] When using a new solution in the chemical solution step, an acidic rinsing step is not necessarily required. Therefore, when using a new solution in the chemical solution step for the first substrate W (first chemical solution step), the acidic rinsing step is omitted, and a neutral rinsing step (first neutral rinsing step) is performed after the first chemical solution step to replace the solution on the main surface of the first substrate W with a neutral rinsing solution. Then, a drying step (first drying step) is performed as needed. On the other hand, the solution used in the first chemical solution step can be recovered and reused in a subsequent chemical solution step for the second substrate W (second chemical solution step). In this case, an acidic rinsing step is performed after the second chemical solution step to replace the acidic solution on the main surface of the substrate W with an acidic rinsing solution. Then, a neutral rinsing step (second neutral rinsing step) is performed to replace the acidic rinsing solution on the main surface of the substrate W with a neutral rinsing solution. Then, a drying step (second drying step) is performed as needed. This eliminates the need for acid rinsing when using new solution, thus shortening processing time and reducing the amount of acid rinsing solution used.

[0056] Figure 2 illustrates the experiment used to verify the above substrate treatment. A calcium contamination solution was supplied to the main surface of a substrate (semiconductor wafer) with a radius of 150 mm. The substrate W was then rotated to spread the calcium contamination solution across the entire main surface of the substrate W. The calcium contamination solution was obtained by dissolving calcium, a type of metallic contaminant, in SC2 (a mixture of hydrochloric acid, hydrogen peroxide, and water), an example of an acidic solution used in the chemical solution step. It is equivalent to a chemical solution containing metallic contaminants. The pH value of the calcium contamination solution was 0.1.

[0057] Next, as a rinsing step, either an acidic rinsing step or a pure water rinsing step (neutral rinsing step) is performed. The acidic rinsing step is performed by supplying dilute nitric acid at a flow rate of 500 mL / min while rotating the substrate W at 100 rpm. The pure water rinsing step is performed by supplying deionized water (DIW) at a flow rate of 500 mL / min while rotating the substrate W at 100 rpm. Afterwards, the substrate W is dried by rotating it at 2500 rpm (rotation drying), and the amount of metal contamination on the substrate surface is evaluated by TXRF (Total reflection X-ray Fluorescence) analysis.

[0058] The rinsing time was set to multiple values ​​within the range of 0 to 12 seconds, and multiple substrate treatment experiments were performed. That is, the rinsing step was performed by either an acidic rinsing step or a pure water rinsing step, and then the amount of metal contamination in each step was evaluated.

[0059] Figure 3A is a graph showing the evaluation results of the pure water rinsing step (comparative example). The vertical axis represents the amount of metal contamination (number of metal atoms per cm², metal contamination density), and the horizontal axis represents the rinsing time (pure water spraying time). The multiple broken lines represent the amount of metal contamination at positions 0 mm, 30 mm, 70 mm, and 140 mm away from the center of the substrate W, respectively. A metal contamination level of 10¹² atoms / cm² was observed, indicating that even extending the rinsing time did not reduce the amount of metal contamination.

[0060] Figure 3B is a graph showing the evaluation results of the acid rinsing step (comparative example) using dilute nitric acid with a pH adjusted to 4 as the acidic rinsing solution. The vertical axis represents the amount of metal contamination (number of metal atoms per cm², metal contamination density), and the horizontal axis represents the rinsing step time (spraying time of dilute nitric acid with pH = 4). The multiple broken lines represent the amount of metal contamination at positions 0 mm, 30 mm, 70 mm, and 140 mm away from the center of the substrate W, respectively. Compared to the pure water rinsing step, the amount of metal contamination is reduced, showing a tendency for the amount of metal contamination to decrease with increasing rinsing time. When the rinsing time is set to 9 seconds, the metal contamination is reduced to the level of 10¹¹ atoms / cm².

[0061] Figure 3C is a graph showing the evaluation results of the acid rinsing step (Example) using dilute nitric acid with a pH adjusted to be the same as that of the calcium contamination solution. The vertical axis represents the amount of metal contamination (number of metal atoms per 1 cm², metal contamination density), and the horizontal axis represents the rinsing step time (spraying time of dilute nitric acid with pH = 0.1). The multiple broken lines represent the amount of metal contamination at positions 0 mm, 30 mm, 70 mm, and 140 mm away from the center of the substrate W, respectively. In the evaluation results obtained by setting the rinsing step time to 3 seconds or more, the amount of metal contamination is below the detection limit, and a clear improvement in the amount of metal contamination can be seen compared with the evaluation results of Figures 3A and 3B.

[0062] The same evaluation results were obtained for potassium, which is a typical metallic pollutant like calcium, but the relevant illustrations are omitted.

[0063] Figure 4 illustrates the mechanism by which an acidic rinsing step can suppress the residue of metallic contaminants. After the acidic solution (in this example, a calcium-contaminated solution) is applied to the main surface of substrate W (in this example, a substrate with silicon oxide on its surface), calcium ions (metal ions) and hydrogen ions are present in the solution. The silicon oxide on the surface of substrate W becomes adsorption sites (SiO-) for adsorbing metal ions and hydrogen ions. Because the concentration of hydrogen ions in the acidic solution (calcium-contaminated solution) is relatively high, the probability of metal ions being adsorbed to these sites is low.

[0064] If deionized water (DIW) is supplied as a neutral rinsing solution, the low hydrogen ion concentration in the deionized water reduces the probability of hydrogen ions being adsorbed to adsorption sites, while increasing the probability of metal ions being adsorbed to adsorption sites. Therefore, if an acidic solution containing metal ions is to be replaced with an aqueous rinsing solution, the metal ions are likely to remain on the main surface of the substrate W.

[0065] On the other hand, if an acidic solution containing metal ions is supplied to the main surface of the substrate W while the acidic solution is present, the acidic solution contains metal ions. In this case, the acidic rinsing solution (dilute nitric acid) has the same or higher hydrogen ion concentration as the acidic solution (i.e., the same or lower pH value as the acidic solution). This allows the acidic solution to replace the acidic solution on the main surface of the substrate W without increasing the probability of metal ions being adsorbed to adsorption sites. This efficiently removes metal ions from the substrate W. Therefore, by replacing the acidic rinsing solution with a neutral rinsing solution afterwards, the substrate processing can be completed while simultaneously suppressing metal ion residue on the substrate W.

[0066] More specifically, the equilibrium reactions of adsorption / desorption of hydrogen ions (H+) and metal ions (Mn+) relative to the adsorption sites (SiO-) on the substrate surface are represented by equations (1) and (2) below. The respective equilibrium constants KH and KM, using molar concentrations, are represented by equations (3) and (4) below.

[0067]

[0068] On the other hand, if we assume that the concentration of adsorption sites σ0 (the number of adsorption sites per mole) is finite, and that at this finite concentration σ0, hydrogen ions (H+) or metal ions (Mn+) are attached individually, then the finite concentration σ0 is expressed as the sum of the concentrations of the sites with adsorbed hydrogen ions (SiOH), the sites with adsorbed metal ions (SiOM), and the sites without adsorbed ions (SiO-). Therefore, the following equation (5) holds.

[0069]

[0070] Therefore, if equations (3), (4) and (5) are combined and the concentration of metal ion adsorption sites (SiOM) is calculated, the following equation (6) can be obtained.

[0071]

[0072] Therefore, it can be concluded that the lower the concentration of hydrogen ions in the liquid present on the main surface of substrate W, i.e., the higher the pH value, the more metal ions are adsorbed. In other words, the higher the concentration of hydrogen ions in the liquid present on the main surface of substrate W, i.e., the lower the pH value, the fewer metal ions are adsorbed.

[0073] Therefore, the acidic rinsing step, performed using an acidic rinsing solution with a pH value below that of the acidic solution used in the chemical solution step, serves to both maintain or reduce the probability of metal being adsorbed onto the main surface of the substrate, and to flush metal ions from the main surface of the substrate W to the outside of the main surface of the substrate W. Thus, even if the acidic solution used in the chemical solution step contains metal contaminants, such as recycled acidic solutions, a substrate treatment with substantially the same quality (at least in terms of residual metal contamination) as when using unused acidic solutions can be achieved by performing a neutral rinsing step after the acidic rinsing step.

[0074] Figure 5 is a schematic top view illustrating an example of the configuration of a substrate processing apparatus 1 according to one embodiment of the present invention. The substrate processing apparatus 1 is a monolithic device for processing substrates W one by one. In this embodiment, the substrate W has a circular shape. The substrate W is a silicon wafer or similar substrate W, and has a pair of main surfaces.

[0075] The substrate processing apparatus 1 includes: a plurality of processing units 2, which process substrates W; a loading port LP (receiving container holding unit) for placing a carrier C (receiving container) for holding a plurality of substrates W, which will be processed in the processing units 2; a transfer robot (first transfer robot IR and second transfer robot CR) for transferring substrates W between the loading port LP and the processing units 2; and a controller 3 for controlling the components of the substrate processing apparatus 1.

[0076] The first transfer robot IR transfers substrate W between carrier C and the second transfer robot CR. The second transfer robot CR transfers substrate W between the first transfer robot IR and processing unit 2. Each transfer robot is, for example, a multi-joint robotic arm.

[0077] A plurality of processing units 2 are arranged on both sides of the transport path TR for the second transport robot CR to transport the substrate W, and are stacked in the vertical direction. The plurality of processing units 2 have, for example, the same configuration.

[0078] A plurality of processing units 2 form four processing towers TWs respectively arranged in four horizontally separated positions. Each processing tower TW contains a plurality of processing units 2 stacked in the vertical direction. Two of the four processing towers TWs are arranged on each side of the transport path TR extending from the loading port LP to the second transport robot CR.

[0079] The substrate processing apparatus 1 includes: a plurality of fluid tanks 4, which house valves or piping, etc.; and a storage tank 5, which houses liquid medicine, rinsing liquid, or a tank for storing such raw materials. The processing unit 2 and the fluid tanks 4 are disposed inside a frame 6 that is generally quadrangular in top view.

[0080] The processing unit 2 has a chamber 7 for receiving the substrate W during substrate processing. The chamber 7 includes: an inlet / outlet (not shown) for the second transfer robot CR to move the substrate W into or out of the chamber 7; and a baffle unit (not shown) for opening or closing the inlet / outlet. Examples of processing fluids supplied to the substrate W within the chamber 7 include pharmaceutical solutions and rinsing solutions, the details of which will be described below.

[0081] Figure 6 is a schematic diagram illustrating the configuration of the processing unit 2. The processing unit 2 includes: a rotating chuck 8, which holds the substrate W in a predetermined processing posture while rotating the substrate W about a rotation axis A1; and a plurality of nozzles (a first movable nozzle 11, a second movable nozzle 12), which spray processing liquid onto the substrate W. The processing unit 2 further includes a processing cup 15, which receives the processing liquid scattered from the substrate W held in the rotating chuck 8. The rotating chuck 8, the plurality of movable nozzles, and the processing cup 15 are disposed within a chamber 7.

[0082] The rotation axis A1 passes through the center of the substrate W and is orthogonal to each main surface of the substrate W held in a processing posture. The processing posture is, for example, the posture of the substrate W shown in Figure 6, a horizontal posture in which the main surfaces of the substrate W are horizontal, but it is not limited to a horizontal posture. That is, the processing posture can also be different from that in Figure 6, in which the main surfaces of the substrate W are tilted relative to the horizontal plane. When the processing posture is horizontal, the rotation axis A1 extends vertically.

[0083] The rotating chuck 8 is an example of a substrate holding member (substrate holding unit, substrate holder) that holds the substrate W in a processing posture, and is also an example of a rotating holding member that holds the substrate W in a processing posture while rotating the substrate W around the rotation axis A1.

[0084] The rotating chuck 8 includes: a rotating base 21 having a circular plate shape along the horizontal direction; a plurality of gripping pins 20 that grip the substrate W above the rotating base 21 and grip the periphery of the substrate W at a position higher than the rotating base 21; a rotating shaft 22 connected to the rotating base 21 and extending in the vertical direction; and a rotation drive mechanism 23 that rotates the rotating shaft 22 about its central axis (rotation axis A1). The rotating base 21 is an example of a circular plate-shaped base.

[0085] The rotary drive mechanism 23 includes, for example, an actuator such as an electric motor. By rotating the rotary shaft 22, the rotary drive mechanism 23 causes the rotary base 21 and a plurality of gripping pins 20 to rotate about the rotation axis A1. Consequently, the substrate W rotates along with the rotary base 21 and the plurality of gripping pins 20 about the rotation axis A1. By using the rotary drive mechanism 23 to rotate the rotary chuck 8 at a predetermined drying speed, centrifugal force can be used to shake off the liquid held on the substrate W in the rotary chuck 8, thereby drying the substrate W. Therefore, the rotary drive mechanism 23 is an example of a drying unit.

[0086] A plurality of gripping pins 20 are spaced apart on the upper surface of the rotating base 21 in the circumferential direction. The plurality of gripping pins 20 are movable between a closed position and an open position. The closed position is when the gripping pins 20 contact the periphery of the substrate W and grip the substrate W; the open position is when the gripping of the substrate W is released. The plurality of gripping pins 20 are moved by an opening and closing mechanism (not shown). When the plurality of gripping pins 20 are in the closed position, they grip the periphery of the substrate W, holding the substrate W horizontally. When the plurality of gripping pins 20 are in the open position, they release the gripping of the substrate W and support the periphery of the substrate W from below. The opening and closing mechanism includes, for example, a linkage mechanism and an actuator that applies a driving force to the linkage mechanism.

[0087] The plurality of movable nozzles include: a first movable nozzle 11 that selectively sprays a continuous flow of treatment liquid (medicine and rinsing liquid in this embodiment) onto the upper surface (main surface of the upper side) of the substrate W held on the rotating chuck 8; and a second movable nozzle 12 that sprays a continuous flow of treatment liquid (medicine in this embodiment) onto the upper surface of the substrate W held on the rotating chuck 8.

[0088] The first movable nozzle 11 is an example of a processing liquid nozzle that sprays processing liquid onto the main surface (upper surface) of the substrate W held in the rotating chuck 8. More specifically, the first movable nozzle 11 is an example of a medicine nozzle (acid medicine nozzle) that sprays a chemical solution (especially an acidic chemical solution) onto the main surface of the substrate W. Furthermore, the first movable nozzle 11 is an example of a rinsing liquid nozzle that sprays rinsing liquid onto the main surface of the substrate W. In this embodiment, at least two types of rinsing liquid can be supplied from the first movable nozzle 11. Specifically, acidic rinsing liquid and neutral rinsing liquid can be sprayed from the first movable nozzle 11. Therefore, the first movable nozzle 11 is an example of an acidic rinsing liquid nozzle that sprays acidic rinsing liquid, and also an example of a neutral rinsing liquid nozzle that sprays neutral rinsing liquid.

[0089] The second movable nozzle 12 is an example of a processing liquid nozzle that sprays processing liquid onto the main surface (upper surface) of the substrate W held in the rotating chuck 8. More specifically, the second movable nozzle 12 is an example of a chemical spray nozzle (acidic chemical spray nozzle) that sprays chemical solution (especially acidic chemical solution) onto the main surface of the substrate W.

[0090] The plurality of movable nozzles move in the horizontal direction by means of the plurality of nozzle drive mechanisms (the first nozzle drive mechanism 25 and the second nozzle drive mechanism 26).

[0091] Each nozzle drive mechanism enables the corresponding moving nozzle to move between a central position and a retracted position. The central position is the position where the moving nozzle faces the central area of ​​the upper surface of the substrate W. The central area of ​​the upper surface of the substrate W refers to the area of ​​the upper surface of the substrate W that includes the rotation center (central portion) and the portion surrounding the rotation center. The retracted position is the position where the moving nozzle is not facing the upper surface of the substrate W, which is the position outside the processing cup 15.

[0092] Each nozzle drive mechanism includes an arm (first arm 25a and second arm 26a) that supports the corresponding movable nozzle, and an arm drive mechanism (first arm drive mechanism 25b and second arm drive mechanism 26b) that moves the corresponding arm in the horizontal direction. Each arm drive mechanism includes actuators such as electric motors and cylinders.

[0093] The movable nozzle can be a rotary nozzle that rotates around a specified axis of rotation, or a linear nozzle that moves linearly in the extension direction of the corresponding arm. The movable nozzle can also be configured to move in the vertical direction.

[0094] The chemical solution sprayed from the first moving nozzle 11 is an acidic solution. The acidic solution may be, for example, an HPM solution (hydrochloric acid-hydrogen peroxide mixture), or more specifically, a so-called SC2 solution (a mixture of hydrochloric acid, hydrogen peroxide, and water). Furthermore, acidic solutions containing hydrofluoric acid (HF), dilute hydrofluoric acid (DHF), buffered hydrofluoric acid (BHF), hydrochloric acid (HCl), sulfuric acid, or a sulfuric acid-hydrogen peroxide mixture (SPM) may also be sprayed from the first moving nozzle 11. Typically, the acidic solution can be used for cleaning processes to remove metallic contaminants from the surface of the substrate W.

[0095] As described above, the rinsing fluid ejected from the first movable nozzle 11 includes both acidic and neutral rinsing fluids. The acidic rinsing fluid is a rinsing fluid with a pH value lower than that of the acidic solution. The neutral rinsing fluid is a rinsing fluid with a pH value higher than that of the acidic rinsing fluid. Typical examples of neutral rinsing fluids are deionized water (DIW) and other water. However, neutral rinsing fluids are not limited to deionized water, but may include deionized water, carbonated water, electrolyzed water, hydrochloric acid diluted (e.g., 1 ppm or more and 100 ppm or less), ammonia diluted (e.g., 1 ppm or more and 100 ppm or less), reduced water (hydrogen water), or a mixture containing at least two of these. Typical examples of acidic rinsing fluids include carbonated water, electrolyzed water, and water with added acid (deionized water), which are appropriately selected based on the pH value of the acidic solution. Typical examples of adding acidic water include diluted hydrochloric acid (hydrogen chloride aqueous solution) and diluted nitric acid (nitric acid aqueous solution).

[0096] Acidic solutions, acidic rinsing solutions, and neutral rinsing solutions are selectively supplied from the first processing liquid supply unit 41 to the first moving nozzle 11. In addition, organic solvents represented by alcohols such as IPA (isopropanol) can also be supplied from the first processing liquid supply unit 41 to the first moving nozzle 11.

[0097] An acidic solution is supplied from the second processing liquid supply unit 42 to the second moving nozzle 12. This acidic solution is the same as the acidic solution sprayed from the first moving nozzle 11. In this embodiment, the acidic solution supplied from the second processing liquid supply unit 42 to the second moving nozzle 12 contains metal contaminants in the form of metal ions. More specifically, in this embodiment, the acidic solution recovered after being used to treat the substrate W is supplied from the second processing liquid supply unit 42 for reuse in substrate treatment. If an acidic solution is used to clean the surface of the substrate W to be treated of metal contaminants, the recovered acidic solution contains metal contaminants in the form of metal ions. This acidic solution is supplied from the second processing liquid supply unit 42 to the second moving nozzle 12.

[0098] The processing cup 15 includes: a plurality of (3 in Figure 6) shields 28, which receive the processing liquid that is dispersed outward from the substrate W held in the rotating chuck 8; a plurality of (3 in Figure 6) receiving cups 29, which respectively receive the processing liquid that is guided downward by the plurality of shields 28; and a cylindrical outer wall member 30 that surrounds the plurality of shields 28 and the plurality of receiving cups 29.

[0099] Each shield 28, viewed from above, has a cylindrical shape that surrounds the rotating chuck 8. The upper end of each shield 28 is inclined inward toward the center of the shield 28. Each cup 29 has an upward-opening annular groove. A plurality of shields 28 and a plurality of cups 29 are arranged on the same shaft.

[0100] The plurality of protective covers 28 are individually raised and lowered by a protective cover raising and lowering drive mechanism 40. The protective cover raising and lowering drive mechanism 40 includes, for example, a plurality of actuators that respectively drive the plurality of protective covers 28 to rise and fall. The plurality of actuators include at least one of an electric motor and a cylinder.

[0101] The processing unit 2 includes an air supply unit 31, such as an FFU (fan filter unit), which blows inert gas from outside the chamber 7 into the chamber 7, and an exhaust pipe 32 for exhausting gas from the chamber 7. The air supply unit 31 is disposed on the upper wall 7a of the chamber 7. The exhaust pipe 32 is connected to the outer wall member 30. The inert gas blown into the chamber 7 by the air supply unit 31 may be, for example, nitrogen, rare gases, or a mixture thereof. A rare gas may be, for example, argon.

[0102] The discharge pipe 32 is connected to the exhaust pipe (not shown). Ambient gas within the exhaust pipe is drawn in by a suction device (not shown). Ambient gas within chamber 7 is discharged to the exhaust pipe via the discharge pipe 32. The suction device includes a suction pump for drawing gas from the exhaust pipe. The suction device is mounted on or connected to the exhaust pipe. The discharge pipe and suction device are installed in a cleanroom or in equipment attached to a cleanroom, wherein the cleanroom is used to house the substrate processing apparatus 1. The exhaust pipe and suction device may also be part of the substrate processing apparatus 1.

[0103] Through the action of the air supply unit 31 and the exhaust pipe 32, an airflow from top to bottom is formed in the internal space 7c of the chamber 7. The airflow passes through the interior of the processing cup 15 and flows into the exhaust pipe 32.

[0104] The processing liquid supplied to the substrate W will scatter from the periphery of the substrate W and be caught by any of the shields 28. The processing liquid caught by the shields 28 will be guided to the corresponding cup 29 and then recycled or discarded through the drain pipes 35 corresponding to each cup 29.

[0105] Figure 7 is a diagram illustrating an example of the configuration of the processing fluid supply system. The processing fluid supply system includes a first processing fluid supply unit 41 that supplies processing fluid to a first movable nozzle 11, and a second processing fluid supply unit 42 that supplies processing fluid to a second movable nozzle 12.

[0106] The first processing fluid supply unit 41 includes a first processing fluid pipe 51 connected to the first movable nozzle 11, a multi-way valve 52 connected to the first processing fluid pipe 51, and a plurality of processing fluid raw material pipes connected to the multi-way valve 52. In this example, the plurality of processing fluid raw material pipes include a hydrochloric acid pipe 53 supplying hydrochloric acid from a hydrochloric acid supply source to the multi-way valve 52, a hydrogen peroxide water pipe 54 supplying hydrogen peroxide water from a hydrogen peroxide water supply source to the multi-way valve 52, a deionized water pipe 55 supplying deionized water from a deionized water supply source to the multi-way valve 52, and a nitric acid pipe 56 supplying nitric acid (an example of an acid) from a nitric acid supply source to the multi-way valve 52.

[0107] The multi-way valve 52 has a manifold 52a, a plurality of inlet valves, and at least one outlet valve. The manifold 52a has a plurality of inlet ports 52b and at least one outlet port 52c. The manifold 52a provides a common flow path for fluid flowing in from the inlet ports 52b to flow in a common manner. Fluid flowing through this common flow path flows out from the outlet port 52c. An inlet valve is connected to each inlet port 52b to open or close that inlet port 52b. An outlet valve is connected to each outlet port 52c to open or close that outlet port 52c.

[0108] A plurality of inlet valves are connected to hydrochloric acid piping 53, hydrogen peroxide water piping 54, deionized water piping 55, and nitric acid piping 56. Hereinafter, the inlet valves connected to hydrochloric acid piping 53, hydrogen peroxide water piping 54, deionized water piping 55, and nitric acid piping 56 are referred to as hydrochloric acid valve 53A, hydrogen peroxide water valve 54A, deionized water valve 55A, and nitric acid valve 56A, respectively. These valves open or close the flow paths of hydrochloric acid piping 53, hydrogen peroxide water piping 54, deionized water piping 55, and nitric acid piping 56, respectively.

[0109] A first processing fluid pipe 51 is connected to the outlet valve. Hereinafter, the outlet valve will be referred to as the first processing fluid valve 51A. The first processing fluid valve 51A opens or closes the flow path of the first processing fluid pipe 51. Each valve includes a valve body and an actuator that moves the valve body between an open position and a closed position, but these are omitted from the relevant diagrams. The other valves to be described below also have the same configuration.

[0110] In the hydrochloric acid piping 53, a hydrochloric acid flow regulating valve 53B for adjusting the flow rate of the fluid (hydrochloric acid) flowing through its path and a filter 53C for removing foreign matter from the fluid (hydrochloric acid) flowing through the path are installed. In this example, the hydrochloric acid flow regulating valve 53B has an actuator for changing the flow rate, and is configured to be electrically controlled. Other flow regulating valves described below have the same configuration.

[0111] Hydrogen peroxide water piping 54 is equipped with a hydrogen peroxide water flow regulating valve 54B for adjusting the flow rate of the fluid flowing through it, i.e., hydrogen peroxide water, and a filter 54C for removing foreign matter from the fluid (hydrogen peroxide water) flowing through it. Similarly, deionized water piping 55 is equipped with a deionized water flow regulating valve 55B for adjusting the flow rate of the fluid flowing through it, i.e., deionized water, and a filter 55C for removing foreign matter from the fluid (deionized water) flowing through it. Likewise, nitric acid piping 56 is equipped with a nitric acid flow regulating valve 56B for adjusting the flow rate of the fluid flowing through it, i.e., nitric acid, and a filter 56C for removing foreign matter from the fluid (nitric acid) flowing through it.

[0112] The opening and closing of the first treatment liquid valve 51A is controlled by the controller 3 (refer to Figures 5 and 8). Furthermore, the opening and closing of the hydrochloric acid valve 53A, hydrogen peroxide water valve 54A, deionized water valve 55A, and nitric acid valve 56A are also controlled by the controller 3. Moreover, the opening degree of the hydrochloric acid flow regulating valve 53B, hydrogen peroxide water flow regulating valve 54B, deionized water flow regulating valve 55B, and nitric acid flow regulating valve 56B is also controlled by the controller 3.

[0113] The controller 3, by opening any one of the hydrochloric acid valve 53A, hydrogen peroxide water valve 54A, deionized water valve 55A, and nitric acid valve 56A, and opening the first processing liquid valve 51A, enables a single processing liquid to be sprayed from the first movable nozzle 11 onto the main surface of the substrate W. For example, by opening the deionized water valve 55A and the first processing liquid valve 51A, while keeping the other valves closed, deionized water (an example of a neutral rinsing liquid) can be sprayed from the first movable nozzle 11 onto the main surface of the substrate W at a flow rate specified by the opening of the deionized water flow rate adjustment valve 55B. Thus, in this embodiment, the first processing liquid supply unit 41 and the first movable nozzle 11 function as an example of a neutral rinsing liquid supply unit.

[0114] Furthermore, the controller 3 can open two or more of the following valves by selecting hydrochloric acid valve 53A, hydrogen peroxide water valve 54A, deionized water valve 55A and nitric acid valve 56A, and open the first processing liquid valve 51A, so that the plurality of processing liquids can be mixed in the manifold 52a (mixed in the piping), and then supplied from the first processing liquid piping 51 to the first moving nozzle 11, and sprayed onto the main surface of the substrate W.

[0115] For example, if the hydrochloric acid valve 53A, hydrogen peroxide water valve 54A, and deionized water valve 55A are open, while other valves are closed, a mixture of these components will be generated due to mixing within the manifold 52a. Therefore, by appropriately controlling the opening of the hydrochloric acid flow regulating valve 53B, the hydrogen peroxide water flow regulating valve 54B, and the deionized water flow regulating valve 55B, the flow ratio of hydrochloric acid, hydrogen peroxide water, and deionized water flowing into the manifold 52a can be controlled, thereby preparing a mixture prepared according to a mixing ratio corresponding to that flow ratio. Thus, by mixing within the manifold 52a (pipeline mixing), an acidic solution (specifically SC2) prepared by mixing hydrochloric acid, hydrogen peroxide water, and deionized water in a specified mixing ratio can be prepared, and then sprayed from the first moving nozzle 11 onto the main surface of the substrate W. Thus, in this embodiment, the first processing liquid supply unit 41 and the first moving nozzle 11 function as an example of an acidic solution supply unit. Furthermore, the first processing liquid supply unit 41 will function as one example of a new liquid supply unit for supplying the main surface of the substrate W with unused acidic liquid (new liquid) that has no history of being used to process the substrate.

[0116] Furthermore, for example, if the deionized water valve 55A and the nitric acid valve 56A are open, while other valves are closed, nitric acid diluted with deionized water can be generated due to mixing within the manifold 52a; in other words, deionized water with added nitric acid. Therefore, by appropriately controlling the opening of the deionized water flow regulating valve 55B and the nitric acid flow regulating valve 56B, the flow ratio of deionized water to nitric acid flowing into the manifold 52a can be controlled, thereby preparing a mixture prepared according to a mixing ratio corresponding to that flow ratio. Thus, by mixing within the manifold 52a (pipeline mixing), an acidic rinsing solution (dilute nitric acid in this example) obtained by adding nitric acid to deionized water can be prepared, and then sprayed from the first movable nozzle 11 onto the main surface of the substrate W. By controlling the flow ratio (mixing ratio) by controlling the deionized water flow regulating valve 55B and the nitric acid flow regulating valve 56B, the amount of nitric acid added relative to the deionized water can be controlled, thereby controlling the pH value of the acidic rinsing solution. Thus, in this embodiment, the first processing liquid supply unit 41 and the first movable nozzle 11 function as one example of an acidic rinsing liquid supply unit. Furthermore, the multi-way valve 52, the deionized water flow regulating valve 55B, and the nitric acid flow regulating valve 56B function as one example of an acidic rinsing liquid preparation unit.

[0117] The second processing fluid supply unit 42 includes an acidic solution tank 60, a second processing fluid piping 61 that allows acidic solution to flow from the acidic solution tank 60 to the second movable nozzle 12, a second processing fluid valve 61A installed in the second processing fluid piping 61, and a second processing fluid flow rate regulating valve 61B also installed in the second processing fluid piping 61. The second processing fluid flow rate regulating valve 61B regulates the flow rate of the acidic solution flowing through the flow path of the second processing fluid piping 61. In this example, the second processing fluid supply unit 42 further includes a filter 61C and a pump 61D installed in the second processing fluid piping 61. The pump 61D draws acidic solution from the acidic solution tank 60 and delivers it from the second processing fluid piping 61 to the second movable nozzle 12. The filter 61C removes foreign matter from the acidic solution flowing through the second processing fluid piping 61.

[0118] The used acidic solution is supplied to the acidic solution tank 60 by the recycling unit 70 for reuse. The recycling unit 70 collects the used acidic solution from the drain pipe 35 (recycling pipe) connected to the receiving cup 29 in the processing cup 15. The receiving cup 29 corresponds to the shield 28 that receives the liquid discharged from the substrate W when the acidic solution is used for processing.

[0119] Specifically, the recovery unit 70 includes a recovery tank 71 for storing the recovered acidic solution (hereinafter referred to as "recovered solution") and a solution transfer pipe 72 for supplying the recovered solution from the recovery tank 71 to the acidic solution tank 60. The solution transfer pipe 72 is equipped with a solution transfer valve 72A, a pump 72B, and a filter 72C. When the solution transfer valve 72A is opened, the pump 72B draws the recovered solution from the recovery tank 71, and the recovered solution, after foreign matter has been removed by the filter 72C, is supplied to the acidic solution tank 60. By recovering and reusing the acidic solution in this way, the amount of acidic solution used can be reduced.

[0120] In this example, a waste pipe 36 branches off from the drain pipe 35 (recovery pipe). By opening or closing the valve 37 located on the drain pipe 35 and the valve 38 located on the waste pipe 36 between the branch point of the waste pipe 36 and the recovery tank 71, it is possible to select whether to recycle and reuse the liquid collected in the receiving cup 29 or to discard it. For example, depending on the processing status on the substrate W, the liquid can be discarded when there are more foreign objects in it, and recycled to the recovery tank 71 when there are fewer foreign objects in it.

[0121] A waste pipe 73 is connected to the recovery tank 71 for discarding the processed liquid stored therein. A waste valve 73A is installed on the waste pipe 73 to open or close its flow path. On the other hand, a metal concentration sensor 74 is installed in the recovery tank 71 to detect the metal concentration (more specifically, metal ion concentration) in the stored recovered liquid. The output signal of the metal concentration sensor 74 is input to the controller 3. When the metal concentration (metal ion concentration) detected by the metal concentration sensor 74 exceeds a preset allowable value, the controller 3 determines that the recovered liquid has reached its usage limit, and thus opens the waste valve 73A to discard the recovered liquid in the recovery tank 71.

[0122] A pH sensor 62 is installed in the acidic solution tank 60 to detect the pH value of the acidic solution stored inside. The pH sensor 62 is one example of a pH value acquisition unit. The output signal of the pH sensor 62 is input to the controller 3. When preparing the acidic rinsing solution by mixing in the piping, the controller 3 sets the mixing ratio of deionized water and nitric acid based on the pH value detected by the pH sensor 62, and controls the opening of the deionized water flow regulating valve 55B and the nitric acid flow regulating valve 56B to make the flow ratio equivalent to the mixing ratio.

[0123] If acidic solutions (recovered acidic solutions and recovered solutions) are stored in the acidic solution tank 60, opening the second processing liquid valve 61A will draw recovered solutions from the acidic solution tank 60 via pump 61D. This recovered solution will be supplied to the second moving nozzle 12 via the second processing liquid piping 61 at a flow rate regulated by the second processing liquid flow adjustment valve 61B, and then supplied from the second moving nozzle 12 to the main surface of the substrate W. Thus, the second processing liquid supply unit 42 and the second moving nozzle 12 function as an example of a recovered solution supply unit.

[0124] Figure 8 is a block diagram illustrating the electrical configuration of the substrate processing device 1. The controller 3 is a computer that includes a computer body 3a and peripheral devices 3d connected to the computer body 3a. The computer body 3a includes a processor (CPU, Central Processing Unit) 3b that executes various commands and a memory 3c that stores information.

[0125] The peripheral device 3d includes an auxiliary memory device 3e for storing information such as programs, a reading device 3f for reading information from a removable medium (not shown), and a communication device 3g for communicating with other devices such as a host computer (not shown).

[0126] The controller 3 is connected to the input device 3A, the display device 3B, and the alarm device 3C. The input device 3A is operated when a user or maintenance supervisor inputs information into the board processing unit 1. The information is displayed on the screen of the display device 3B. The input device 3A can be any of a keyboard, pointing device, or touch panel, or other devices. A touch panel display that serves as both the input device 3A and the display device 3B can also be provided on the board processing unit 1. The alarm device 3C uses light, sound, text, and graphics to issue an alarm. When the input device 3A is a touch panel display, it can also function as the alarm device 3C.

[0127] The auxiliary memory device 3e is a non-volatile memory that can retain memories without power. Examples of auxiliary memory devices 3e include magnetic memory devices such as hard drives.

[0128] The auxiliary memory device 3e stores multiple process recipes. Each process recipe specifies the processing content, conditions, and procedures for the substrate W. The multiple process recipes differ from each other in at least one aspect of the processing content, conditions, and procedures for the substrate W.

[0129] The controller 3 controls the components of the substrate processing device 1 to process the substrate W according to the process formula specified by the host computer or other external device.

[0130] Examples of objects controlled by controller 3 include the first conveying robot IR, the second conveying robot CR, the rotary drive mechanism 23, the first nozzle drive mechanism 25, the second nozzle drive mechanism 26, the protective cover lifting drive mechanism 40, the air supply unit 31, pumps 61D and 72B, valves 37 and 38, the first treatment liquid valve 51A, the hydrochloric acid valve 53A, the hydrochloric acid flow regulating valve 53B, the hydrogen peroxide water valve 54A, the hydrogen peroxide water flow regulating valve 54B, the deionized water valve 55A, the deionized water flow regulating valve 55B, the nitric acid valve 56A, the nitric acid flow regulating valve 56B, the second treatment liquid valve 61A, the second treatment liquid flow regulating valve 61B, the drug transfer valve 72A, and the waste valve 73A. Controller 3 will also receive output signals from the pH sensor 62 and the metal concentration sensor 74.

[0131] Furthermore, only representative components are shown in Figure 8. This does not mean that components not shown are not controlled by the controller 3. The controller 3 can appropriately control the various components of the substrate processing device 1.

[0132] The following steps are executed by the controller 3 controlling the board processing device 1. In other words, the controller 3 is programmed to execute the following steps.

[0133] Figure 9 is a flowchart illustrating an example of substrate processing performed by the substrate processing apparatus 1. One of the two main surfaces of the substrate W to be processed is the processing target surface. Metal contaminants are present on this processing target surface. The cleaning process for removing these metal contaminants is performed by the substrate processing apparatus 1.

[0134] The untreated substrate W is moved from the carrier C into the processing unit 2 by the first transfer robot IR (see Figure 5), and then transferred to the rotary chuck 8 by the second transfer robot CR (step S11: substrate loading step). The rotary chuck 8 holds the substrate W horizontally (substrate holding step). At this time, the substrate W is held in the rotary chuck 8 with the processing surface as the upper surface. The substrate W is held by the rotary chuck 8 until the drying step (step S16) ends and the substrate unloading step (step S18) is performed.

[0135] With the substrate W held on the rotating chuck 8, the rotation drive mechanism 23 causes the substrate W to start rotating (step S12: start of substrate rotation step).

[0136] With the first moving nozzle 11 positioned above the substrate W and the substrate W rotating at a predetermined liquid processing speed (e.g., 100 rpm), an acidic solution is sprayed from the first moving nozzle 11 onto the upper surface (the surface to be processed) of the substrate W (step S13: first solution step). Specifically, in the first processing liquid supply unit 41, the hydrochloric acid valve 53A, the hydrogen peroxide water valve 54A, and the deionized water valve 55A are opened, and then the first processing liquid valve 51A is opened. The nitric acid valve 56A is closed. Furthermore, the opening degrees of the hydrochloric acid flow rate regulating valve 53B, the hydrogen peroxide water flow rate regulating valve 54B, and the deionized water flow rate regulating valve 55B are adjusted so that the flow rate ratio of hydrochloric acid, hydrogen peroxide water, and deionized water is equivalent to their predetermined mixing ratio. Thus, SC2 is prepared by mixing within the manifold 52a of the multi-way valve 52 (pipeline mixing) (mixing step), and the prepared SC2 is sprayed as an acidic solution from the first moving nozzle 11 onto the upper surface of the substrate W. The acidic solution reaching the upper surface of the substrate W diffuses to the entire upper surface of the substrate W by centrifugal force, removing metallic contaminants from the upper surface of the substrate W. This is how the first solution step is performed. In the first solution step, the first moving nozzle 11 can stop when the acidic solution adheres to the vicinity of the rotation center of the upper surface of the substrate W, or it can move to scan the upper surface of the substrate W by moving the contact point between the rotation center and the vicinity of the outer periphery.

[0137] During the execution of the first liquid treatment step, the acidic liquid that is thrown outward from the upper surface of the substrate W is caught by the pre-set liquid recovery shield 28 and flows down to the corresponding receiving cup 29. The acidic liquid is recovered to the recovery tank 71 through the drain pipe 35 (step S14: first liquid recovery step).

[0138] After the first chemical solution step has been completed for a predetermined time, the supply of acidic chemical solution is stopped, and instead, neutral rinsing solution is sprayed from the first moving nozzle 11 onto the upper surface of the substrate W (step S15: first neutral rinsing step). That is, in the first processing liquid supply unit 41, the hydrochloric acid valve 53A and the hydrogen peroxide water valve 54A are closed. The deionized water valve 55A and the first processing liquid valve 51A are kept open, and the nitric acid valve 56A is kept closed. The opening of the deionized water flow rate adjustment valve 55B is controlled to supply deionized water at a flow rate suitable for rinsing. In this way, the deionized water is sprayed as neutral rinsing solution from the first moving nozzle 11 and supplied to the upper surface of the substrate W. The neutral rinsing solution reaching the upper surface of the substrate W diffuses to the entire upper surface of the substrate W by centrifugal force, replacing the acidic chemical solution on the upper surface of the substrate W. The first neutral rinsing step is performed in this way. In the first neutral rinsing step, the first moving nozzle 11 can stop when the neutral rinsing liquid is attached to the center of rotation on the upper surface of the substrate W, or it can move in a way that scans the upper surface of the substrate W by moving the liquid contact point between the center of rotation and the vicinity of the outer periphery.

[0139] During the first neutral rinsing step, the liquid ejected from the upper surface of the substrate W outwards is caught by a pre-set waste disposal shield 28 and flows down to the corresponding cup 29. The liquid is then discarded through the drain pipe 35.

[0140] After the first neutral rinsing step has been performed for a specified time, the supply of neutral rinsing fluid is stopped. That is, the disconnect sub-water valve 55A is closed, and the first moving nozzle 11 is moved from above the substrate W to a retraction position set on the outside of the substrate W.

[0141] Next, the rotation of the rotary chuck 8 is accelerated to a specified drying speed (e.g., 2500 rpm), and the neutral rinsing liquid on the substrate W is removed by centrifugal force (rotational drying). This is performed as the first drying step (step S16). After the first drying step is completed, the rotary chuck 8 is stopped rotating, and the substrate stops rotating as well (step S17: end of substrate rotation step). Then, the processed substrate W is removed from the rotary chuck 8 by the second transfer robot CR (step S18).

[0142] As described above, the following steps are performed on a substrate W: a first chemical solution step (step S13), which involves supplying unused acidic chemical solution (new solution) to the main surface of the substrate W (the first substrate); a first neutral rinsing step (step S15), which involves replacing the acidic chemical solution on the main surface of the substrate W with a neutral rinsing solution; and a first drying step (step S16), which involves removing the neutral rinsing solution from the main surface of the substrate W. This series of processes is performed on one or more substrates W (e.g., a plurality of substrates constituting a batch) until a predetermined amount of acidic chemical solution (recovered chemical solution) is stored in the recovery tank 71.

[0143] After storing a predetermined amount of recycled chemical solution in the recycling tank 71, the chemical solution transfer valve 72A is opened, and the recycled chemical solution is transferred from the recycling tank 71 to the acidic chemical solution tank 60 by the operation of the pump 72B, thus preparing for the supply of recycled chemical solution from the acidic chemical solution tank 60. After storing a sufficient amount of recycled chemical solution in the acidic chemical solution tank 60, the recycled chemical solution stored in the acidic chemical solution tank 60 can be used in the chemical solution step for the substrate W (second substrate) to be processed later.

[0144] That is, the second transfer robot CR delivers the substrate W (second substrate) to the rotary chuck 8 (step S21: substrate loading step), and after the substrate W begins to rotate (step S22: start of substrate rotation step), with the second moving nozzle 12 positioned above the substrate W and the substrate W rotating at a specified liquid processing speed (e.g., 100 rpm), acidic solution (recovery solution) is sprayed from the second moving nozzle 12 onto the upper surface (processing target surface) of the substrate W (step S23: second solution step). Specifically, the second processing liquid valve 61A is opened, thereby supplying acidic solution to the upper surface of the substrate W from the second moving nozzle 12 at a flow rate adjusted by the second processing liquid flow adjustment valve 61B. The acidic solution reaching the upper surface of the substrate W diffuses to the entire upper surface of the substrate W by centrifugal force, removing metallic contaminants from the upper surface of the substrate W. This is how the second solution step is performed. In the second liquid treatment step, the second moving nozzle 12 can stop when the acidic liquid is attached to the upper surface of the substrate W at the center of rotation, or it can move to scan the upper surface of the substrate W by moving the liquid application point between the center of rotation and the outer periphery.

[0145] During the second chemical solution step, the acidic chemical solution thrown outward from the upper surface of the substrate W is caught by the pre-set chemical solution recovery shield 28 and flows down to the corresponding receiving cup 29. The acidic chemical solution is recovered to the recovery tank 71 through the drain pipe 35 (step S24: second chemical solution recovery step).

[0146] After the second chemical solution step has been completed for a predetermined time, the supply of acidic chemical solution is stopped, and instead, acidic rinsing solution is sprayed from the first moving nozzle 11 onto the upper surface of the substrate W. That is, in the second processing solution supply unit 42, the second processing solution valve 61A is closed. Then, the second moving nozzle 12 is retracted from above the substrate W to a retracted position set on the outside of the substrate W. On the other hand, the first moving nozzle 11 is positioned above the substrate W, and in the first processing solution supply unit 41, the deionized water valve 55A and the nitric acid valve 56A are opened, and then the first processing solution valve 51A is opened. The hydrochloric acid valve 53A and the hydrogen peroxide water valve 54A are closed.

[0147] The controller 3 reads the output signal of the pH sensor 62 to obtain the pH value of the acidic solution in the acidic solution tank 60 (step S25: pH value acquisition step). The controller 3 sets the pH value below the pH value of the acidic solution as the target pH value of the acidic rinsing solution (step S26: target pH value setting step). In order to achieve the target pH value, the controller 3 calculates the mixing ratio of deionized water and nitric acid, and controls the opening of the deionized water flow regulating valve 55B and the nitric acid flow regulating valve 56B to make the flow ratio equivalent to the mixing ratio (step S27: mixing ratio setting step). In this state, the deionized water valve 55A, nitric acid valve 56A and first treatment liquid valve 51A are opened, thereby preparing an acidic rinsing solution with the target pH value by mixing in the manifold 52a of the multi-way valve 52 (step S28: mixing step, piping mixing step, acidic rinsing solution preparation step), and the acidic rinsing solution is supplied from the first moving nozzle 11 to the upper surface of the substrate W (step S29: acidic rinsing step).

[0148] The acidic rinsing solution reaching the upper surface of the substrate W is diffused to the entire upper surface of the substrate W by centrifugal force, replacing the acidic solution on the upper surface of the substrate W. This is how the acidic rinsing step is performed. During the acidic rinsing step, the first moving nozzle 11 can stop when the acidic rinsing solution adheres to the center of rotation on the upper surface of the substrate W, or it can move by scanning the upper surface of the substrate W according to the position of the contact point between the center of rotation and the vicinity of the outer periphery.

[0149] During the acid rinsing process, the liquid ejected from the upper surface of the substrate W outwards is caught by a pre-set waste disposal shield 28 and flows down to the corresponding cup 29. The liquid is then disposed of through the drain pipe 35.

[0150] After the acidic rinsing step has been performed for a specified time, the supply of acidic rinsing solution is stopped, and instead, neutral rinsing solution is sprayed from the first moving nozzle 11 onto the upper surface of the substrate W. Specifically, in the first processing solution supply unit 41, the nitric acid valve 56A is closed. The deionized water valve 55A and the first processing solution valve 51A are kept open, while the hydrochloric acid valve 53A and the hydrogen peroxide water valve 54A are kept closed. The opening of the deionized water flow rate regulating valve 55B is controlled to supply deionized water at a flow rate suitable for the rinsing process. Thus, the deionized water is sprayed as neutral rinsing solution from the first moving nozzle 11 and supplied to the upper surface of the substrate W (step S30: second neutral rinsing step). The neutral rinsing solution reaching the upper surface of the substrate W diffuses to the entire upper surface of the substrate W by centrifugal force, replacing the acidic rinsing solution on the upper surface of the substrate W. This is how the second neutral rinsing step is performed. In the second neutral rinsing step, the first moving nozzle 11 can stop when the acidic solution is attached to the center of rotation on the upper surface of the substrate W, or it can move in a way that scans the upper surface of the substrate W by moving the contact point between the center of rotation and the vicinity of the outer periphery.

[0151] During the second neutral rinsing step, the liquid ejected from the upper surface of the substrate W outwards is caught by a pre-set waste disposal shield 28 and flows down to the corresponding cup 29. The liquid is then discarded through the drain pipe 35.

[0152] After the second neutral rinsing step has been performed for a specified time, the supply of neutral rinsing fluid is stopped. That is, the disconnect sub-water valve 55A is closed, and the first moving nozzle 11 is moved from above the substrate W to a retraction position set on the outside of the substrate W.

[0153] Next, the rotation of the rotary chuck 8 is accelerated to a specified drying speed (e.g., 2500 rpm), and the neutral rinsing liquid on the substrate W is removed by centrifugal force (rotational drying). This is performed as the second drying step (step S31). After the second drying step is completed, the rotary chuck 8 is stopped rotating, and the substrate W stops rotating accordingly. Then, the processed substrate W is removed from the rotary chuck 8 by the second transfer robot CR.

[0154] As described above, the following steps are performed on a substrate W: a second chemical solution step (step S24), which involves supplying a recycled chemical solution, i.e., an acidic chemical solution, to the main surface of the substrate W (the second substrate); an acidic rinsing step (step S29), which involves replacing the acidic chemical solution on the main surface of the substrate W with an acidic rinsing solution; a second neutral rinsing step (step S30), which involves replacing the acidic rinsing solution on the main surface of the substrate W with a neutral rinsing solution; and a second drying step (step S31), which involves removing the neutral rinsing solution from the main surface of the substrate W. This series of processes is performed on one or more substrates W (e.g., a plurality of substrates constituting a batch).

[0155] The acidic solution supplied by the first processing solution supply unit 41 is unused solution, i.e., fresh solution. Therefore, the concentration of metallic contaminants remaining in the acidic solution on the substrate W after the first solution step (step S13) using the fresh solution will not be too high. Therefore, there is no need to perform an acidic rinsing step. By replacing the acidic solution on the substrate W with a neutral rinsing solution in the first neutral rinsing step (step S15), the metallic contaminants can be removed from the surface of the substrate W.

[0156] The acidic solution supplied from the second processing solution supply unit 42 is the solution recovered after treating the substrate (recovered solution). Therefore, the concentration of metallic contaminants remaining on the substrate W after the second processing solution step (step S24) using the recovered solution will be relatively high. Therefore, an acidic rinsing step (step S29) is performed after the second processing solution step (step S24) to replace the acidic solution on the substrate W with an acidic rinsing solution having a pH value lower than that of the acidic solution. This allows the metallic contaminants on the substrate W to be flushed away from the substrate W. Subsequently, by replacing the acidic rinsing solution on the substrate W with a neutral rinsing solution in the second neutral rinsing step (step S30), a cleaning process with a quality approximately equivalent to that in the case of using fresh solution in the processing solution step can be performed.

[0157] In this way, although recycled chemicals are used, substrate treatment with essentially the same quality as when using new chemicals can be achieved, thereby reducing the amount of chemicals used.

[0158] Figure 10 is a diagram illustrating another configuration example of the treatment fluid supply system. In Figure 10, the same reference numerals are used to label the parts that are the same as those in Figure 7. In this configuration example, the first treatment fluid supply unit 41 supplies acidic rinsing fluid and neutral rinsing fluid to the first moving nozzle 11. The second treatment fluid supply unit 42 supplies unused acidic solution (new solution) and recycled acidic solution (recovered solution) to the second moving nozzle 12.

[0159] The first treatment fluid supply unit 41 is configured such that a deionized water pipe 55 and a nitric acid pipe 56 are connected to a multi-way valve 52. A deionized water valve 55A and a deionized water flow regulating valve 55B are installed in the deionized water pipe 55, and a nitric acid valve 56A and a nitric acid flow regulating valve 56B are installed in the nitric acid pipe 56. According to this configuration, by opening the deionized water valve 55A, deionized water can be supplied as a neutral rinsing solution to the first movable nozzle 11. Furthermore, the deionized water and nitric acid valves 56A can be opened to mix the deionized water and nitric acid in the manifold 52a to prepare an acidic rinsing solution, which is then supplied to the first movable nozzle 11.

[0160] In the second processing liquid supply unit 42, the acidic liquid tank 60 is equipped with hydrochloric acid piping 83, hydrogen peroxide water piping 84, and deionized water piping 85, which supply hydrochloric acid, hydrogen peroxide water, and deionized water, respectively. Hydrochloric acid piping 83 is equipped with a hydrochloric acid valve 83A and a hydrochloric acid flow meter 83B. Hydrogen peroxide water piping 84 is equipped with a hydrogen peroxide water valve 84A and a hydrogen peroxide water flow meter 84B. Deionized water piping 85 is equipped with a deionized water valve 85A and a deionized water flow meter 85B. The hydrochloric acid valve 83A, hydrogen peroxide water valve 84A, and deionized water valve 85A are on / off valves that open or close their corresponding flow paths, controlled by the controller 3 (see Figure 8). Furthermore, the output signals of the hydrochloric acid flow meter 83B, hydrogen peroxide water flow meter 84B, and deionized water flow meter 85B are input to the controller 3 (see Figure 8).

[0161] According to this configuration, hydrochloric acid, hydrogen peroxide water, and deionized water can be supplied to the acidic solution tank 60 from the hydrochloric acid pipe 53, the hydrogen peroxide water pipe 54, and the deionized water pipe 55, so that the hydrochloric acid, hydrogen peroxide water, and deionized water are mixed in the acidic solution tank 60 to prepare an acidic solution (more specifically, SC2). Thus, unused acidic solution (fresh solution) can be supplied from the acidic solution tank 60 to the second movable nozzle 12 and sprayed onto the upper surface of the substrate W. Furthermore, once the recovered acidic solution in the recovery tank 71 reaches a predetermined amount, it can be transferred to the acidic solution tank 60 for processing the substrate W.

[0162] When preparing an acidic solution (new solution) in the acidic solution tank 60, the controller 3 opens the hydrochloric acid valve 83A, the hydrogen peroxide water valve 84A, and the deionized water valve 85A, and accumulates the hydrochloric acid flow rate, hydrogen peroxide water flow rate, and deionized water flow rate detected by the hydrochloric acid flow meter 83B, the hydrogen peroxide water flow meter 84B, and the deionized water flow meter 85B. The controller 3 presets the hydrochloric acid supply rate, hydrogen peroxide water supply rate, and deionized water supply rate according to a specified mixing ratio. When the accumulated flow rate of hydrochloric acid reaches the preset hydrochloric acid supply rate, the controller 3 closes the hydrochloric acid valve 83A; when the accumulated flow rate of hydrogen peroxide water reaches the preset hydrogen peroxide water supply rate, the controller 3 closes the hydrogen peroxide water valve 84A; and when the accumulated flow rate of deionized water reaches the preset deionized water supply rate, the controller 3 closes the deionized water valve 85A. In this way, hydrochloric acid, hydrogen peroxide water, and deionized water can be mixed in the acidic solution tank 60 according to a specified mixing ratio to prepare an acidic solution suitable for substrate processing. As described above, the second processing solution supply unit 42 has the function of being an example of an acidic rinsing solution preparation unit.

[0163] In this configuration example, the first processing liquid supply unit 41 and the first movable nozzle 11 are examples of acidic rinsing liquid supply units and also examples of neutral rinsing liquid supply units. The second processing liquid supply unit 42 and the second movable nozzle 12 are examples of acidic drug solution supply units, as well as examples of new liquid supply units and recycled liquid supply units.

[0164] The embodiments of the present invention have been described above, but the present invention may also be implemented in other ways, as illustrated in the following illustrative examples.

[0165] In the above embodiment, the acidic flushing solution is prepared by mixing within the manifold 52a of the multi-way valve 52. However, the acidic flushing solution can also be prepared by mixing deionized water and acid in a tank (mixing step, tank mixing step). The trace amount of acid added to the deionized water to prepare the acidic flushing solution is nitric acid in the above embodiment, but it can also be other acids such as hydrochloric acid.

[0166] In the above embodiment, the pH value of the acidic solution in the acidic solution tank 60 is detected. However, if the pH value of the acidic solution is known, the pH value detection can be omitted.

[0167] The second treatment liquid supply unit 42 in Figure 7 includes a recovery tank 71 and an acidic liquid tank 60, but these can also be combined into one tank, so that the one tank can serve as both a recovery tank and an acidic liquid tank.

[0168] The above embodiments are configured to spray the treatment liquid from a plurality of movable nozzles. However, unlike the above embodiments, the treatment liquid may also be sprayed from a fixed nozzle with a fixed position in the horizontal direction. Furthermore, a plurality of treatment liquids may be sprayed from individual nozzles.

[0169] In the above embodiments, the rotary chuck 8 is a gripping rotary chuck that grips the periphery of the substrate W by means of a plurality of gripping pins 20, but the rotary chuck 8 is not limited to a gripping rotary chuck. For example, the rotary chuck 8 can also be a vacuum adsorption rotary chuck that adsorbs the substrate W onto the rotating base 21.

[0170] In the above embodiments, the controller 3 controls the entire board processing device 1. However, controllers for each component of the board processing device 1 can also be distributed in multiple locations. Furthermore, the controller 3 does not need to directly control each component; signals output from the controller 3 can be received by the slave controllers of each component of the board processing device 1.

[0171] Furthermore, in the above embodiments, the substrate processing apparatus 1 includes a transfer robot (a first transfer robot IR and a second transfer robot CR), a plurality of processing units 2, and a controller 3. However, the substrate processing apparatus 1 may also include a single processing unit 2 and a controller 3, without a transfer robot. Alternatively, the substrate processing apparatus 1 may also include only a single processing unit 2. In other words, the processing unit 2 may also be an example of a substrate processing apparatus.

[0172] Furthermore, while the above embodiments describe a single-piece substrate processing apparatus, the present invention can also be applied to a batch substrate processing apparatus that uniformly immerses multiple substrates in a processing tank for processing.

[0173] Although embodiments of the present invention have been described in detail, they are merely specific examples used to clarify the technical content of the present invention. The present invention should not be limited to these specific examples for interpretation, and the scope of the present invention is limited only by the appended claims. [Related Applications]

[0174] This application claims priority based on Japanese Patent Application No. 2023-039493, filed on March 14, 2023, the entire contents of which are incorporated herein by reference.

[0175] 1: Substrate processing device 2: Processing Unit 3: Controller 3A: Input device 3a: Computer body 3B: Display device 3b: Processor 3C: Alarm Device 3c: Memory 3D: Peripheral Devices 3e: Auxiliary memory device 3f: Reading device 3G: Communication device 4: Fluid box 5: Storage box 6: Framework 7: Chamber 7a: Upper wall 7c: Interior space 8: Rotary Chuck 11: First moving nozzle 12: Second moving nozzle 15: Processing Cup 20: Holding pin 21: Rotating base 22: Rotation axis 23: Rotary drive mechanism 25: Nozzle 1 drive mechanism 25a: First Arm 25b: First arm drive mechanism 26: Second Nozzle Drive Mechanism 26a: Second Arm 26b: Second arm drive mechanism 28: Protective shield 29: Holding the Cup 30: External wall components 31: Air supply unit 32: Discharge piping 35: Drainage piping 40: Protective cover lifting drive mechanism 41: First processing fluid supply unit 42: Second processing fluid supply unit 51: First treatment fluid piping 51A: First processing fluid valve 52: Multi-way valve 52a: manifold 52b: Port 52c: Export Port 53: Hydrochloric acid piping 53A: Hydrochloric acid valve 53B: Hydrochloric acid flow regulating valve 53C: Filter 54: Hydrogen peroxide water piping 54A: Hydrogen peroxide water valve 54B: Hydrogen peroxide water flow regulating valve 54C: Filter 55: Detachable submersible water piping 55A: Separator water valve 55B: De-idling water flow regulating valve 55C: Filter 56:Nitric acid piping 56A: Nitric Acid Valve 56B: Nitric acid flow regulating valve 56C: Filter 60: Acidic chemical solution tank 61: Second treatment fluid piping 61A: Second processing fluid valve 61B: Second processing fluid flow control valve 61C: Filter 61D: Pump 62: pH sensor 70: Recycling Unit 71: Recycling Tank 72: Drug solution transfer piping 72A: Drug transfer valve 72B: Pump 72C: Filter 73: Discarded piping 73A: Waste Valve 74: Metal Concentration Sensor 83: Hydrochloric acid piping 83A: Hydrochloric acid valve 83B: Hydrochloric acid flow meter 84: Hydrogen peroxide water piping 84A: Hydrogen peroxide water valve 84B: Hydrogen peroxide water flow meter 85: Detachable submersible water piping 85A: Separator water valve 85B: Deionizer Water Flow Meter A1: Axis of rotation C: Vehicle CR: Second transport robot IR: First transport robot LP: Loading Port S17~S18, S21~31: Steps TR: Transport Path TW: Processing Tower W: substrate

Claims

1. A substrate processing method, comprising: a solution step, wherein an acidic solution is supplied to a main surface of the substrate; an acidic rinsing step, wherein an acidic rinsing solution with a pH value adjusted to be below the pH value (hydrogen ion index) of the acidic solution is supplied to the main surface of the substrate to replace the acidic solution on the main surface of the substrate; a neutral rinsing step, wherein a neutral rinsing solution with a pH value higher than the acidic rinsing solution is supplied to the main surface of the substrate to replace the acidic rinsing solution on the main surface of the substrate; a pH value acquisition step, wherein the pH value of the acidic solution used in the solution step is acquired; and an acidic rinsing solution preparation step, wherein an acidic rinsing solution with a pH value below the pH value obtained in the pH value acquisition step is prepared; and the acidic rinsing step supplies the acidic rinsing solution prepared in the acidic rinsing solution preparation step to the main surface of the substrate.

2. The substrate processing method of claim 1, wherein the pH value acquisition step includes a step of detecting the pH value of the acidic solution used in the solution step by means of a pH value sensor.

3. The substrate processing method of claim 1 or 2, wherein the acidic rinsing solution preparation step comprises: a target pH value setting step, which sets the target pH value based on the pH value obtained by the pH value acquisition step; and a mixing step, which generates the acidic rinsing solution by mixing a neutral rinsing solution and an acid in a mixing ratio, wherein the mixing ratio is set based on the target pH value set by the target pH value setting step.

4. The substrate processing method of claim 1 or 2, wherein the above-mentioned chemical solution step involves supplying an acidic chemical solution containing metal ions to the main surface of the substrate.

5. The substrate processing method of claim 1 or 2 further includes a drying step of removing the neutral rinsing liquid from the main surface of the substrate and drying the main surface of the substrate.

6. A substrate processing apparatus comprising: a substrate holding unit for holding a substrate; an acidic solution supply unit for supplying an acidic solution to a main surface of the substrate held in the substrate holding unit; an acidic rinsing solution supply unit for supplying an acidic rinsing solution to the main surface of the substrate held in the substrate holding unit, the pH value of which has been adjusted to be below the pH value (hydrogen ion index) of the acidic solution; a neutral rinsing solution supply unit for supplying a neutral rinsing solution to the main surface of the substrate held in the substrate holding unit, the pH value of which is greater than that of the acidic rinsing solution; a drying unit for drying the main surface of the substrate held in the substrate holding unit; and a pH value acquisition unit for acquiring the pH value of the acidic solution supplied by the acidic solution supply unit, wherein the acidic rinsing solution supply unit includes an acidic rinsing solution preparation unit for preparing an acidic rinsing solution with a pH value below that obtained by the pH value acquisition unit.

7. The substrate processing apparatus of claim 6, further comprising a controller for controlling the acidic solution supply unit, the acidic rinsing solution supply unit, the neutral rinsing solution supply unit, and the drying unit, wherein the controller is programmed to perform the following steps: a solution supply step, wherein the acidic solution is supplied to the main surface of the substrate by the acidic solution supply unit; an acidic rinsing step, wherein the acidic rinsing solution is supplied to the main surface of the substrate by the acidic rinsing solution supply unit to replace the acidic solution on the main surface of the substrate; and a neutral rinsing step, wherein the acidic solution is supplied to the main surface of the substrate by the neutral rinsing solution supply unit. The process includes: a neutral rinsing solution to replace the acidic rinsing solution on the main surface of the substrate; a drying step to remove the neutral rinsing solution from the main surface of the substrate by means of the drying unit, thereby drying the main surface of the substrate; a pH value acquisition step to obtain the pH value of the acidic solution used in the solution acquisition step by means of the pH value acquisition unit; and an acidic rinsing solution preparation step to prepare an acidic rinsing solution with a pH value lower than that obtained in the pH value acquisition step by means of the acidic rinsing solution preparation unit; and the acidic rinsing step to supply the acidic rinsing solution prepared in the acidic rinsing solution preparation step to the main surface of the substrate.

8. The substrate processing apparatus of claim 6 or 7, wherein the pH value acquisition unit includes a pH value sensor for detecting the pH value of the acidic solution supplied by the acidic solution supply unit.

9. The substrate processing apparatus of claim 6 or 7, wherein the aforementioned acidic solution supply unit supplies an acidic solution containing metal ions to the main surface of the substrate.

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