Substrate processor, method for processing substrate, and method for manufacturing semiconductor device

Abstract

To provide a substrate processor with small process variations, a method for processing a substrate, and a method for manufacturing a semiconductor device.SOLUTION: A substrate processor according to the present embodiment includes: a processing tank for storing a medicine and immersing a substrate in the medicine to process the substrate; a holding member for holding the substrate, the holding member having a lifting mechanism; a medicine supply device for supplying the medicine; a light radiation mechanism for radiating light to the substrate taken out of the processing tank by the lifting mechanism after immersing the substrate in the medicine; a light detection mechanism for detecting the light reflected by the substrate; and a controller for controlling the medicine supply amount of the medicine supply device according to the result of detection by the light detection mechanism.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to a substrate processing apparatus, a substrate processing method, and a method for manufacturing a semiconductor device. [Background technology]

[0002] In some cases, a substrate having a laminate in which silicon nitride films and silicon oxide films are alternately formed is selectively etched to selectively etch the silicon nitride film relative to the silicon oxide film. In this case, a phosphoric acid solution is generally used as an etching solution. In such an etching process, the phosphoric acid solution may be reused several times while partially replacing it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-18703 A [Patent Document 2] JP 2023-56689 A [Patent Document 3] Patent Publication No. 2022-17131 [Patent Document 4] Patent Publication No. 2022-184615 [Patent Document 5] JP 2019-50360 A [Patent Document 6] JP 2018-50001 A [Patent Document 7] JP 2018-142695 A [Patent Document 8] JP 2013-232593 A [Patent Document 9] JP 2012-28580 A Summary of the Invention [Problem to be solved by the invention]

[0004] Advantageous Effects of Invention The embodiments according to the present disclosure provide a substrate processing apparatus, a substrate processing method, and a method for manufacturing a semiconductor device with reduced process variations. [Means for solving the problem]

[0005] A substrate processing apparatus according to one embodiment includes a processing tank for storing a chemical and processing a substrate by immersing it in the chemical, a holding member for holding the substrate and having a lifting mechanism, a chemical supplying device for supplying the chemical, a light irradiation mechanism for irradiating light onto the substrate which has been immersed in the chemical and then removed from the processing tank by the lifting mechanism, a light detection mechanism for detecting light reflected by the substrate, and a control device for controlling the amount of chemical supplied by the chemical supplying device in accordance with the detection result of the light detection mechanism. [Brief description of the drawings]

[0006] [Figure 1] 1 is a diagram illustrating an overall configuration of a substrate processing apparatus according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a schematic diagram illustrating a light irradiation mechanism and a light detection mechanism according to an embodiment. [Diagram 3] 1 is a cross-sectional view of a substrate that is subject to an etching process according to an embodiment. [Figure 4] FIG. 2 is a flow diagram illustrating a substrate processing method according to an embodiment. [Diagram 5] 1A and 1B are diagrams illustrating a method of light irradiation and light detection according to an embodiment. [Figure 6] FIG. 2 is a flow diagram illustrating a substrate processing method according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] The substrate processing apparatus, substrate processing method, and semiconductor device manufacturing method according to the present embodiment will be specifically described below with reference to the drawings. In the following description, elements having substantially the same functions and configurations are given the same reference numerals or the same reference numerals followed by an alphabet, and will be described repeatedly only when necessary. Each embodiment shown below exemplifies an apparatus and method for embodying the technical idea of ​​this embodiment. Various modifications can be made to one embodiment without departing from the gist of the invention. These embodiments and their modifications are included within the scope of the invention described in the claims and their equivalents.

[0008] In order to clarify the description, the drawings may show the width, thickness, shape, etc. of each part in a schematic manner compared to the actual embodiment, but these are merely examples and do not limit the interpretation of the present invention. In this specification and each drawing, elements having the same functions as those described in the previous drawings may be given the same reference numerals, and duplicate descriptions may be omitted.

[0009] In this specification, unless otherwise specified, an expression such as "α includes A, B, or C" does not exclude cases where α includes multiple combinations of A to C. Furthermore, these expressions do not exclude cases where α includes other elements.

[0010] In this specification, the term "horizontal" may refer to a direction (XY direction) that is horizontal to the bottom surface of the inner tank, and the term "vertical" may refer to a direction (Z direction) that is approximately perpendicular to the horizontal direction.

[0011] The following embodiments and modifications can be combined with each other.

[0012] First Embodiment [Substrate processing equipment] Fig. 1 is a diagram showing a schematic overall configuration of a substrate processing apparatus according to an embodiment. The substrate processing apparatus 1 according to this embodiment is a batch processing apparatus, for example, a wet etching processing apparatus that removes a silicon nitride film (not shown in Fig. 1) provided on a substrate 20 with a solution 30 containing phosphoric acid (hereinafter, referred to as phosphoric acid solution). As shown in Fig. 1, the substrate processing apparatus 1 includes a processing tank 11, a circulation path 12, a heating unit 13, a chemical liquid supplying device 14, a pump 15, a filter 16, a holding member 17, a discharge path 18, a valve 19, a control device 50, a light irradiation mechanism 60, and a light detection mechanism 70.

[0013] The processing tank 11 is a container having an inner tank 111 and an outer tank 112. The inner tank 111 is formed in a box shape having an upper end opening 111a. The inner tank 111 stores therein a phosphoric acid solution 30, that is, an etching liquid (processing liquid) for a silicon nitride film. The temperature, phosphoric acid concentration, and silica concentration of the phosphoric acid solution 30 stored inside the inner tank 111 are optimized for etching the silicon nitride film provided on the substrate 20.

[0014] The inner tank 111 can accommodate wafer-shaped (disc-shaped) substrates 20 vertically (with the main surface parallel to the vertical direction (YZ direction)). Inside the inner tank 111, the holding member 17 can accommodate the substrates 20 arranged in multiple rows in the horizontal direction (X direction) at predetermined intervals, and in FIG. 1, for example, the holding member 17 holds 18 substrates 20 in the inner tank 111. However, this is not limited to the above, and for example, a maximum of 50 substrates 20 may be accommodated in one inner tank 111.

[0015] The holding member 17 may include a lifting mechanism 171 that lifts and lowers the held substrate 20 in a vertical direction (Z direction) relative to the inner bath 111. By the lifting and lowering action of the lifting mechanism 171, the substrate 20 before etching can be automatically immersed in the phosphoric acid solution 30 stored in the inner bath 111, and the substrate 20 after etching can be automatically removed from the inner bath 111.

[0016] When the substrate 20 is immersed in the phosphoric acid solution 30, the silicon nitride film provided on the substrate 20 is dissolved in the phosphoric acid solution 30 and removed from the substrate 20. For this reason, the inner tank 111 has a depth sufficient to completely immerse the substrate 20 placed vertically in the phosphoric acid solution 30. An upper opening 111a of the inner tank 111 is higher than the upper end of the substrate 20 placed vertically.

[0017] The outer tank 112 has an upper end opening 112a that completely surrounds the upper end opening 111a of the inner tank 111. The outer tank 112 collects the phosphoric acid solution 30 that has overflowed from the upper end opening 111a of the inner tank 111.

[0018] The circulation path 12 communicates with the bottom of the outer tank 112 and the bottom of the inner tank 111, and circulates the phosphoric acid solution 30 through the treatment tank 11. Specifically, the circulation path 12 returns the phosphoric acid solution 30 that has flowed out into the outer tank 112 to the inner tank 111. In the process of returning, the phosphoric acid solution 30 passes through a heating unit 13, a pump 15, and a filter 16.

[0019] The heating unit 13 is disposed midway through the circulation path 12. The heating unit 13 heats the phosphoric acid solution 30. The heating unit 13 is, for example, a line heater that uses a halogen lamp as a heat source.

[0020] In this embodiment, the heating control unit 13a adjusts the heating temperature of the heating unit 13 so that the phosphoric acid solution 30 is heated at a constant temperature. The phosphoric acid solution 30 (heated solution) heated by the heating unit 13 is supplied to the inside of the inner tank 111 through the filter 16.

[0021] The chemical supplying device 14 is disposed above the outer tank 112. The chemical supplying device 14 puts a chemical into the outer tank 112. The chemical supplying device 14 is, for example, a nozzle or a pipe connected to a chemical storage tank. The chemical is, for example, water, a phosphoric acid liquid in which phosphoric acid is condensed, an additive, or a phosphoric acid solution in which phosphoric acid liquid and an additive are mixed. The concentration of the phosphoric acid solution 30 recovered in the outer tank 112 changes due to the evaporation of water in the inner tank 111 and the etching process. For example, the silica concentration in the phosphoric acid solution 30 increases as the silicon nitride film 222 dissolves. In addition, the concentration of the additive adsorbed to the substrate 20 decreases in the phosphoric acid solution 30.

[0022] Water may be supplied from the chemical liquid supplying device 14 in order to adjust the concentration of the phosphoric acid solution 30 returned to the inner tank 111 to an optimum concentration for selective etching of the silicon nitride film. The chemical liquid supplying device 14 may supply phosphoric acid liquid or an additive instead of water to the outer tank 112. The chemical liquid supplying device 14 may also supply phosphoric acid solution 30, which has been adjusted in advance to an optimum concentration for etching of the silicon nitride film, i.e., the same phosphoric acid concentration as the phosphoric acid solution 30 initially stored in the inner tank 111 (the phosphoric acid solution 30 before the heating solution is supplied), to the outer tank 112. The amount of water, phosphoric acid liquid, additive or phosphoric acid solution supplied by the chemical liquid supplying device 14 is controlled by the control device 50.

[0023] The pump 15 is disposed upstream of the heating unit 13 in the circulation path 12. The pump 15 sucks the phosphoric acid solution 30 from the outer tank 112, so that the phosphoric acid solution 30 collected in the outer tank 112 moves to the heating unit 13. The pump 15 also pressurizes the phosphoric acid solution 30 heated in the heating unit 13, so that the phosphoric acid solution 30 is supplied to the inner tank 111.

[0024] The filter 16 is disposed downstream of the heating unit 13 in the circulation path 12. The filter 16 removes particles contained in the phosphoric acid solution 30 in the circulation path 12. The particles include, for example, silica dissolved in the phosphoric acid solution 30 by the etching process of the substrate 20. The filter 16 may be disposed upstream of the heating unit 13 in the circulation path 12.

[0025] The discharge path 18 is connected to the inner tank 111 and discharges the phosphoric acid solution 30 to the drain when, for example, replacing a portion of the phosphoric acid solution 30 used in the etching process. A valve 19 is disposed in the discharge path 18. The amount of phosphoric acid solution 30 discharged by the valve 19 is controlled by a control device 50.

[0026] FIG. 2 is a schematic diagram showing the light irradiation mechanism and the light detection mechanism according to the present embodiment. As shown in FIG. 1 and FIG. 2, the light irradiation mechanism 60 and the light detection mechanism 70 are disposed above the upper end opening 111a of the inner tank 111. The light irradiation mechanism 60 is disposed opposite the substrate 20 so that the light can be irradiated onto the substrate 20 immediately after etching, which has been removed from the inner tank 111 by the lifting and lowering action of the lifting and lowering mechanism 171. The light detection mechanism 70 is disposed opposite the substrate 20 so that the reflected light of the light incident on the substrate 20 can be detected. The angle between the light irradiated by the light irradiation mechanism 60 and the substrate 20 is not particularly limited. The positions of the light irradiation mechanism 60 and the light detection mechanism 70 with respect to the substrate 20 may be within a range in which the light detection mechanism 70 can detect the reflected light of the light irradiated by the light irradiation mechanism 60. The position at which the light irradiation mechanism 60 irradiates the substrate 20 with light is not particularly limited. The positions of the light irradiation mechanism 60 and the light detection mechanism 70 with respect to the substrate 20 may always be constant.

[0027] The light irradiation mechanism 60 and the light detection mechanism 70 are disposed facing the back surface of the substrate 20 opposite to the main surface (the surface on which the laminated body including the silicon nitride film is formed). The light irradiated by the light irradiation mechanism 60 is reflected by the back surface of the substrate 20 and detected by the light detection mechanism 70. The substrate 20 immediately after the etching process, which is taken out of the inner tank 111 by the lifting and lowering operation of the lifting and lowering mechanism 171, contains the phosphoric acid solution 30 on the front surface (main surface and back surface) of the substrate 20. Therefore, the light irradiated by the light irradiation mechanism 60 is reflected by the back surface of the substrate 20 via the phosphoric acid solution 30 on the front surface of the substrate 20 and detected by the light detection mechanism 70. The reflectance obtained from the intensity of the reflected light detected by the light detection mechanism 70 varies depending on the amount and composition of the phosphoric acid solution 30 on the front surface of the substrate 20. For example, if the amount of phosphoric acid solution 30 remaining on the front surface of the substrate 20 is large, the reflectance becomes small, and if the concentration of the composition of the phosphoric acid solution 30 remaining on the front surface of the substrate 20 is high, the reflectance may become small. Alternatively, the reflectance may increase when a large amount of phosphoric acid solution 30 remains on the surface of substrate 20, and the reflectance may increase when the concentration of the composition of phosphoric acid solution 30 remaining on the surface of substrate 20 is high.

[0028] The wavelength of the light irradiated by the light irradiation mechanism 60 is not particularly limited. The wavelength of the light irradiated by the light irradiation mechanism 60 may be, for example, 350 nm or more and 2500 nm or less. The light irradiated by the light irradiation mechanism 60 may include light of a single wavelength or may include light of multiple wavelengths. The intensity of the light irradiated by the light irradiation mechanism 60 can be selected appropriately. The light source of the light irradiation mechanism 60 is not particularly limited. The light source of the light irradiation mechanism 60 may be, for example, a halogen lamp, a deuterium lamp, a xenon lamp, or the like.

[0029] The wavelength of the light detected by the light detection mechanism 70 is not particularly limited. The light detected by the light detection mechanism 70 may be light of a single wavelength or light of multiple wavelengths. The photodetector of the light detection mechanism 70 may be, for example, a photomultiplier tube, a silicon photodiode, an InGaAs photodiode, a PbS photoconductive element, or the like. The reflectance obtained from the intensity of the reflected light detected by the light detection mechanism 70 is supplied to the control device 50.

[0030] The control device 50 controls the amount of water, phosphoric acid liquid, additive or phosphoric acid solution supplied by the chemical solution supply device 14 and the amount of phosphoric acid solution 30 discharged by the valve 19 according to the reflectance obtained from the intensity of reflected light detected by the light detection mechanism 70.

[0031] The substrate processing apparatus according to this embodiment can obtain the reflectance by irradiating the substrate 20 immediately after etching with light by the light irradiation mechanism 60 and the light detection mechanism 70 and detecting the reflected light. The reflectance varies depending on the amount and composition of the phosphoric acid solution 30 remaining on the surface of the substrate 20, so that the state of the phosphoric acid solution 30 after etching, which cannot be detected by existing methods, can be grasped. By controlling the supply amount of water, phosphoric acid liquid, additive or phosphoric acid solution by the chemical supply device 14 and the discharge amount of the phosphoric acid solution 30 by the valve 19 according to the reflectance, the state of the phosphoric acid solution 30 can be kept constant for each etching process, and a substrate processing apparatus with little process variation can be provided.

[0032] [Substrate processing method] Hereinafter, a description will be given of a substrate processing method using the substrate processing apparatus 1 according to this embodiment. The substrate processing method according to this embodiment is carried out, for example, as part of a method for manufacturing a semiconductor device.

[0033] 3 is a cross-sectional view of a substrate 20 to be etched. The substrate 20 is, for example, a semiconductor substrate for manufacturing a stacked memory in which electrode layers are stacked. As shown in FIG. 3, the substrate 20 has a silicon substrate 21 and a stacked film 22. The stacked film 22 includes a silicon oxide film 221 and a silicon nitride film 222 that are alternately stacked. The substrate 20 also has a trench 23 penetrating the stacked film 22.

[0034] 4 is a flow diagram illustrating a substrate processing method. First, the substrate 20 is etched (S401). The substrate 20 held by the holding member 17 is accommodated in the inner tank 111 by the lifting operation of the lifting mechanism 171. The substrate 20 is immersed in the phosphoric acid solution 30 stored in the inner tank 111. The phosphoric acid solution 30 permeates into the laminated film 22 from the trenches 23 of the substrate 20. This removes the silicon nitride film 222. At this time, the silica concentration in the phosphoric acid solution 30 increases due to the dissolved silicon nitride film 222.

[0035] The phosphoric acid solution 30 contains, for example, an additive that is adsorbed to the surface of the silicon oxide film 221. The additive is adsorbed to the surface of the silicon oxide film 221 that is exposed by removing the silicon nitride film 222. The type of additive is not particularly limited. The material of the additive may be, for example, a silane coupling agent. The concentration of the additive in the phosphoric acid solution 30 decreases as the process is repeated or as the additive is adsorbed to the substrate 20. In addition, as the additive is adsorbed to the substrate 20, the dynamic contact angle of the phosphoric acid solution 30 (how the phosphoric acid solution 30 is cut) changes. Note that, in the space from which the silicon nitride film 222 has been removed, an electrode layer is formed by a subsequent process using another device.

[0036] After the etching process is completed, the substrate 20 is removed from the inner bath 111 by the lifting action of the lifting mechanism 171, and light is irradiated by the light irradiation mechanism 60 (S402). FIG. 5 is a diagram for explaining the light irradiation and light detection methods. Immediately after the substrate 20 is removed from the inner bath 111, phosphoric acid solution 30 remains on the surface of the substrate 20. The amount of phosphoric acid solution 30 remaining on the surface of the substrate 20 varies depending on the state of the surface of the substrate 20 and the composition of the phosphoric acid solution 30. The composition of the phosphoric acid solution 30 varies depending on the etching process. Therefore, the light irradiated by the light irradiation mechanism 60 passes through the phosphoric acid solution 30 on the surface of the substrate 20 and is incident on the back surface of the substrate 20 opposite to the main surface.

[0037] The light reflected by the back surface of the substrate 20 is detected by the light detection mechanism 70 (S403). The reflectance obtained from the intensity of the reflected light detected by the light detection mechanism 70 varies depending on the amount and composition of the phosphoric acid solution 30 on the surface of the substrate 20. The reflectance obtained from the intensity of the reflected light detected by the light detection mechanism 70 is transmitted to the control device 50.

[0038] The control device 50 judges whether the received reflectance is within the range of the tolerance information, and if the reflectance is within the range of the tolerance information, ends the substrate processing and starts the processing of the next substrate.

[0039] If the reflectance is outside the range of the allowable information, an alert may be output indicating that the phosphoric acid solution 30 is not suitable for the next etching process (S405). However, the present invention is not limited to this, and the process may automatically proceed to the next step.

[0040] If the reflectance is outside the range of the allowable information, the control device 50 transmits a chemical supply instruction to the chemical supply device 14 and transmits a chemical discharge instruction to the valve 19 (S406). The valve 19 that has received the chemical discharge instruction discharges the designated amount of phosphoric acid solution 30, and the chemical supply device 14 that has received the chemical supply instruction puts the designated amount of chemical (for example, water, phosphoric acid solution, additive, or phosphoric acid solution) into the outer tank 112.

[0041] The water, phosphoric acid liquid, additive or phosphoric acid solution introduced into the outer tank 112 is mixed with the phosphoric acid solution 30 remaining in the inner tank 111 via the circulation path 12 and circulated to the processing tank 11, thereby optimizing the phosphoric acid solution 30 for the next substrate processing. The phosphoric acid solution 30 overflowing from the inner tank 111 is collected in the outer tank 112. The phosphoric acid solution 30 collected in the outer tank 112 is sucked by the pump 15 and sent to the heating unit 13. The heating unit 13 heats the phosphoric acid solution 30. The phosphoric acid solution 30 heated in the heating unit 13 is circulated inside the inner tank 111 by the pump 15.

[0042] The allowable reflectance information may be acquired in advance by sampling correlation data between the reflectance and the pattern analysis result of the substrate 20. However, without being limited thereto, the allowable reflectance information may be acquired in advance by sampling correlation data between the reflectance and the silica concentration or the etching rate of the silicon oxide film. The previously acquired correlation data may be stored in the control device 50, for example. In this case, it may be determined whether the reflectance is within or outside the allowable information range based on the acquired reflectance and the previously stored correlation data, and an optimal supply amount of the agent may be determined.

[0043] In the substrate processing method using the substrate processing apparatus 1 according to this embodiment, the light irradiation mechanism 60 and the light detection mechanism 70 irradiate the substrate 20 immediately after the etching process with light, and detect the reflected light, thereby obtaining the reflectance. The reflectance varies depending on the amount and composition of the phosphoric acid solution 30 remaining on the surface of the substrate 20, and therefore the state of the phosphoric acid solution 30 after the etching process, which cannot be detected by existing methods, can be grasped. By controlling the supply amount of water, phosphoric acid liquid, additive, or phosphoric acid solution by the chemical supply device 14 and the discharge amount of the phosphoric acid solution 30 by the valve 19 according to the reflectance, the state of the phosphoric acid solution 30 for each etching process can be kept constant, and a substrate processing method with little process variation can be provided.

[0044] In the present embodiment, the light detection mechanism 70 detects the reflected light to obtain the reflectance, and transmits the obtained reflectance to the control device 50. However, the present invention is not limited to this, and the light detection mechanism 70 may directly transmit the intensity of the detected reflected light to the control device 50. The control device 50 may obtain the reflectance from the intensity of the received reflected light and determine whether the obtained reflectance is within the range of the allowable information. Furthermore, the allowable information is not limited to the reflectance, and may be the intensity or absorbance of the reflected light. In this case, the control device 50 may determine whether the intensity of the received reflected light is within the range of the allowable information, or may obtain the absorbance from the intensity of the received reflected light and determine whether the obtained absorbance is within the range of the allowable information.

[0045] <Variation 1> The configuration of the substrate processing apparatus according to this modification is the same as that of the substrate processing apparatus according to the first embodiment. The substrate processing method according to this embodiment is the same as the substrate processing method according to the first embodiment, except that reflected light is measured over time. Explanations of the same things as in the first embodiment will be omitted, and only differences from the substrate processing method according to the first embodiment will be described here.

[0046] 6 is a flow diagram illustrating a substrate processing method. The etching process of the substrate 20 (S501), the irradiation of light by the light irradiation mechanism 60 (S502), and the detection of reflected light by the light detection mechanism 70 (S503) are the same as those in the first embodiment, so the description thereof will be omitted here. The reflectance obtained from the intensity of the reflected light detected by the light detection mechanism 70 is transmitted to the control device 50.

[0047] The control device 50 judges whether the received reflectance is within a specified range (S504). If the reflectance is within the specified range, the light irradiation mechanism 60 repeats the irradiation of light (S502) and the light detection mechanism 70 detects the reflected light (S503) over time.

[0048] The specified value of the reflectance may be a lower limit or an upper limit of the reflectance that changes over time and is sampled in advance, but is not limited thereto, and may be determined based on whether the time when the reflectance is received is within a specified time.

[0049] If the reflectance is outside the range of the specified values, the control device 50 judges whether the received rate of change in reflectance is within the range of the tolerance information (S505). If the rate of change in reflectance is within the range of the tolerance information, the substrate processing is terminated and the next substrate processing is started.

[0050] If the rate of change in reflectance is outside the range of the allowable information, an alert may be output indicating that the phosphoric acid solution 30 is not suitable for the next etching process (S506). However, the present invention is not limited to this, and the process may automatically proceed to the next step.

[0051] If the rate of change in reflectance is outside the range of the allowable information, the control device 50 transmits a chemical supply instruction to the chemical supply device 14 and transmits a chemical discharge instruction to the valve 19 (S506). The valve 19 that has received the chemical discharge instruction discharges the designated amount of phosphoric acid solution 30, and the chemical supply device 14 that has received the chemical supply instruction pours the designated amount of water, phosphoric acid solution, additive, or phosphoric acid solution into the outer tank 112.

[0052] The water, phosphoric acid liquid, additives or phosphoric acid solution introduced into the outer tank 112 is mixed with the phosphoric acid solution 30 via the circulation path 12 and circulated to the processing tank 11, thereby optimizing the phosphoric acid solution 30 for the next substrate processing.

[0053] The allowable information on the rate of change in reflectance may be acquired in advance by sampling correlation data between the rate of change in reflectance and the pattern analysis results of the substrate 20.

[0054] In the substrate processing method using the substrate processing apparatus 1 according to this modification, the light irradiation mechanism 60 and the light detection mechanism 70 irradiate the substrate 20 immediately after the etching process with light, and the reflected light is detected over time, and this is repeated to obtain the rate of change in reflectance. Since the reflectance changes depending on the amount and composition of the phosphoric acid solution 30 remaining on the surface of the substrate 20, it is possible to grasp the state of the phosphoric acid solution 30 after the etching process, which cannot be detected by existing methods. By controlling the supply amount of water, phosphoric acid liquid, additive, or phosphoric acid solution by the chemical solution supply device 14 and the discharge amount of the phosphoric acid solution 30 by the valve 19 according to the reflectance, the state of the phosphoric acid solution 30 for each etching process can be kept constant, and a substrate processing method with little process variation can be provided.

[0055] In this modified example, the light detection mechanism 70 detects the reflected light over time to obtain the rate of change in reflectance, and transmits the obtained rate of change in reflectance to the control device 50. However, the present invention is not limited to this, and the light detection mechanism 70 may directly transmit the intensity of the reflected light detected over time to the control device 50. The control device 50 may obtain the reflectance from the intensity of the received reflected light and determine whether the obtained rate of change in reflectance is within the range of the allowable information. Furthermore, the allowable information is not limited to the rate of change in reflectance, and may be the rate of change in the intensity of the reflected light or the rate of change in absorbance. In this case, the control device 50 may determine whether the rate of change in the intensity of the received reflected light is within the range of the allowable information, or may obtain the rate of change in absorbance from the intensity of each received reflected light and determine whether the obtained rate of change in absorbance is within the range of the allowable information. [Explanation of symbols]

[0056] REFERENCE SIGNS LIST 1 substrate processing apparatus, 11 processing tank, 12 circulation path, 13 heating section, 14 chemical supply device, 15 pump, 16 filter, 17 holding member, 18 drain path, 19 valve, 20 substrate, 30 phosphoric acid solution, 50 control device, 60 light irradiation mechanism, 70 light detection mechanism

Claims

1. a treatment tank capable of storing a chemical and immersing a substrate in the chemical to perform treatment; a holding member that holds the substrate and has a lifting mechanism; A drug solution supplying device for supplying the drug; a light irradiation mechanism that irradiates light onto the substrate that has been immersed in the agent and then removed from the treatment bath by the lifting mechanism; a light detection mechanism that detects light reflected by the substrate; a control device that controls an amount of chemical supplied by the chemical supply device in accordance with a detection result of the light detection mechanism.

2. The substrate processing apparatus according to claim 1 , wherein the control device controls an amount of chemical discharged in response to a detection result of the light detection mechanism.

3. The light irradiation mechanism irradiates the light over time, The substrate processing apparatus of claim 1 , wherein the light detection mechanism detects the reflected light over time.

4. the light irradiation mechanism irradiates the light of a plurality of wavelengths; The substrate processing apparatus of claim 1 , wherein the light detection mechanism detects the reflected light of a plurality of wavelengths.

5. the substrate has a first surface on which a stack of silicon nitride films and silicon oxide films are alternately disposed, and a second surface opposite to the first surface; The substrate processing apparatus according to claim 1 , wherein the light irradiation mechanism irradiates the second surface of the substrate with the light.

6. The substrate processing apparatus according to claim 5 , wherein the chemical is a phosphoric acid solution containing an additive that is adsorbed to the silicon oxide film.

7. a substrate processing apparatus including a processing tank for storing a chemical and for processing a substrate by immersing the substrate in the chemical, a holding member for holding the substrate and having a lifting mechanism, a chemical supplying device for supplying the chemical, a light irradiation mechanism for irradiating the substrate with light, a light detection mechanism for detecting light reflected by the substrate, and a control device for controlling an amount of chemical supplied by the chemical supplying device in accordance with a detection result of the light detection mechanism; The substrate is immersed in the agent by the lifting mechanism; removing the substrate from the processing bath by the lifting mechanism; irradiating the substrate with light by the light irradiation mechanism; The substrate processing method further comprises detecting reflected light of the light reflected by the substrate by the light detection mechanism.

8. a substrate processing apparatus including: a processing tank for storing a chemical and capable of processing a semiconductor substrate by immersing the chemical in the chemical; a holding member for holding the semiconductor substrate and having a lifting mechanism; a chemical supplying device for supplying the chemical; a light irradiating mechanism for irradiating the semiconductor substrate with light; a light detecting mechanism for detecting light reflected by the semiconductor substrate; and a control device for controlling an amount of chemical supplied by the chemical supplying device in accordance with a detection result of the light detecting mechanism; The semiconductor substrate is immersed in the agent by the lifting mechanism; removing the semiconductor substrate from the processing bath by the lifting mechanism; irradiating the semiconductor substrate with light by the light irradiation mechanism; The light detection mechanism detects reflected light from the semiconductor substrate.

9. the semiconductor substrate has a laminate in which silicon nitride films and silicon oxide films are alternately formed, The method for manufacturing a semiconductor device according to claim 8 , wherein the chemical is a phosphoric acid solution.

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