Substrate processing device and substrate processing method

Abstract

The present invention provides a substrate processing device and a substrate processing method. A substrate processing device, comprising: a mixing unit, which mixes a first phosphoric acid as a raw material of a processing liquid and an additive at a predetermined mixing ratio to prepare a mixed liquid; a mixing ratio correction unit for correcting the mixing ratio of the raw materials of the processing liquid; a processing unit for processing substrates with the processing liquid, the mixing unit is used for a mixing tank for storing the mixed liquid; a first phosphoric acid supply unit for supplying the first phosphoric acid to the mixing tank; and an additive supply unit for supplying the additive to the mixing tank, the mixing ratio correction unit having: a liquid supply line for transporting the mixed liquid from the mixing unit to the processing unit; and a second phosphoric acid supply unit for supplying a second phosphoric acid in the middle of the liquid supply line. In this way, the mixing ratio of phosphoric acid and the additive can be appropriately changed.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing device and a substrate processing method. Background Art

[0002] The substrate processing device described in Patent Document 1 includes a processing unit, a circulation line, a heating unit, and a first dosing unit. The processing unit removes a silicon nitride film from a substrate using an etching solution containing phosphoric acid and a silicon oxide precipitation inhibitor. The circulation line circulates the etching solution relative to the processing unit. The heating unit heats the etching solution. The first dosing unit is provided on the circulation line and dosing the silicon oxide precipitation inhibitor into the etching solution.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent document 1: Japanese Patent Application Publication No. 2017-118092. Summary of the invention

[0006] Problems to be solved by the invention

[0007] One aspect of the present invention provides a technology capable of appropriately changing the mixing ratio of phosphoric acid and an additive.

[0008] Technical solutions to solve problems

[0009] A substrate processing device according to one embodiment of the present invention comprises: a mixing unit for mixing a first phosphoric acid as a raw material of a processing liquid and an additive at a predetermined mixing ratio to prepare a mixed liquid; a mixing ratio correction unit for correcting the mixing ratio of the raw materials of the processing liquid; a processing unit for processing a substrate with the processing liquid, the mixing unit having a mixing tank for storing the mixed liquid; a first phosphoric acid supply unit for supplying the first phosphoric acid to the mixing tank; and an additive supply unit for supplying the additive to the mixing tank, the mixing ratio correction unit comprising: a liquid supply line for transporting the mixed liquid from the mixing unit to the processing unit; and a second phosphoric acid supply unit for supplying a second phosphoric acid in the middle of the liquid supply line.

[0010] Effects of the Invention

[0011] According to one aspect of the present invention, the mixing ratio of phosphoric acid and the additive can be appropriately changed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a diagram showing a substrate processing apparatus according to one embodiment.

[0013] Figure 2 This is a diagram showing the mixing ratio of raw materials of the treatment liquid according to one embodiment.

[0014] Figure 3AIt is a cross-sectional view showing a state of a substrate before being processed according to one embodiment.

[0015] Figure 3B Yes means Figure 3A A cross-sectional view of the substrate after processing is shown.

[0016] Figure 4 This is a diagram showing a processing unit according to one embodiment.

[0017] Figure 5 It is a diagram showing the operation of the substrate processing apparatus according to one embodiment.

[0018] Figure 6 This is a flow chart showing the preparation of a mixed solution according to one embodiment.

[0019] Figure 7 This is a diagram showing the relationship between the first mixing ratio (M:N) and the number of supply times N according to one embodiment.

[0020] Figure 8 This is a flowchart showing the supply of a mixed solution to a processing unit according to one embodiment.

[0021] Fig. 9 This is a diagram showing the relationship between the mixing ratio of the raw materials of the treatment liquid and the second mixing ratio (Q2:Q1) according to one embodiment.

[0022] Fig.10 This is a diagram showing the relationship between the number of substrates per batch and the sum of Q1 and Q2 (Q1+Q2) according to one embodiment.

[0023] Fig.11 It is a diagram showing a substrate processing apparatus according to a modified example.

[0024] Explanation of symbols

[0025] 1. Substrate processing device

[0026] 2 Substrate

[0027] 22 Silicon oxide film

[0028] 23 Silicon nitride film

[0029] 24 Laminated Film

[0030] 25 Opening

[0031] 27 Pattern

[0032] 3 Treatment fluid

[0033] 5 Mixing section

[0034] 51 Mixing tank

[0035] 52. First phosphoric acid supply unit

[0036] 53. First additive supply unit

[0037] 54 loop routes

[0038] 6 Mixing ratio correction unit

[0039] 61 Liquid delivery line

[0040] 61a Upstream Route

[0041] 61b Downstream line (separate piping)

[0042] 62. Second phosphoric acid supply unit

[0043] 65 Buffer tank

[0044] 66 loop routes

[0045] 7 Processing Department

[0046] 9 Control Unit DETAILED DESCRIPTION

[0047] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each of the drawings, the same or corresponding structures are denoted by the same reference numerals and their description may be omitted.

[0048] Figure 1 It is a diagram showing a substrate processing apparatus according to one embodiment. Figure 2 This is a diagram showing the mixing ratio of raw materials of the treatment liquid according to one embodiment. Figure 3A It is a cross-sectional view showing a state of a substrate before being processed according to one embodiment. Figure 3B Yes means Figure 3A A cross-sectional view of the substrate after processing is shown.

[0049] The substrate processing device 1 processes the substrate 2 with the processing liquid 3. For example, Figure 3A As shown, the substrate 2 includes a silicon wafer 21, a silicon oxide film 22, and a silicon nitride film 23. The silicon oxide film 22 and the silicon nitride film 23 are alternately and repeatedly stacked to form a stacked film 24. A conductive film (not shown) and the like are formed between the stacked film 24 and the silicon wafer 21. The stacked film 24 includes an opening 25 that penetrates the stacked film 24 in the thickness direction.

[0050] The treatment liquid 3 contains phosphoric acid and enters the opening 25 of the laminated film 24. Figure 3BAs shown, the silicon nitride film 23 of the silicon oxide film 22 and the silicon nitride film 23 is selectively etched and removed. The etching selectivity is determined by the silicon concentration in the processing liquid 3, etc. The higher the silicon concentration, the higher the selectivity. On the other hand, if the silicon concentration exceeds the saturation concentration, silicon oxide will precipitate. Therefore, the processing liquid 3 contains a silicon oxide precipitation inhibitor. The silicon oxide precipitation inhibitor is an additive for inhibiting the precipitation of silicon oxide, and is a general additive.

[0051] The processing liquid 3 enters the opening 25 of the stacked film 24 and etches the silicon nitride film 23 in the in-plane direction. The in-plane direction refers to the direction orthogonal to the thickness direction. As the etching of the silicon nitride film 23 proceeds, silicon dissolves inside the stacked film 24. The dissolved silicon diffuses mainly according to the gradient of silicon concentration, passes through the opening 25 of the stacked film 24, and diffuses to the outside of the stacked film 24. The deeper the depth from the surface 26 of the stacked film 24 and the farther the distance from the opening 25, the longer the diffusion distance, so the higher the silicon concentration.

[0052] As described above, the silicon concentration varies depending on the location, and its highest value is determined by the pattern 27 of the substrate 2 to be treated with the treatment liquid 3. The pattern 27 to be treated is a pattern to be removed, that is, a pattern of paths where dissolved silicon diffuses. The pattern 27 is a three-dimensional pattern.

[0053] The pattern 27 of the substrate 2 includes the number of stacked films 24 and the interval S of the openings 25. As the number of stacked films 24 increases and the interval S of the openings 25 increases, the diffusion distance increases, and thus the maximum value of the silicon concentration increases.

[0054] The pattern 27 of the substrate 2 includes the film thickness T of each silicon nitride film 23 and the width W of the opening 25. Since the width of the silicon diffusion path becomes narrower as the film thickness T of each silicon nitride film 23 becomes smaller and the width W of the opening 25 becomes narrower, the maximum value of the silicon concentration becomes higher.

[0055] As described above, the maximum value of the silicon concentration is determined by the pattern 27 of the substrate 2. Therefore, the substrate processing apparatus 1 changes the concentration of the silicon oxide precipitation inhibitor contained in the processing liquid 3 based on the pattern 27 of the substrate 2. For example, the higher the maximum value of the silicon concentration, the higher the concentration of the silicon oxide precipitation inhibitor. As a result, the precipitation of silicon oxide can be suppressed.

[0056] like Figure 1As shown, the substrate processing device 1 includes, for example, a mixing unit 5, a mixing ratio correction unit 6, and a processing unit 7. The mixing unit 5 mixes the first phosphoric acid as the raw materials of the processing liquid 3 with the silicon oxide precipitation inhibitor at a predetermined first mixing ratio (M:N) to prepare the mixed liquid. The mixing ratio correction unit 6 corrects the mixing ratio of the raw materials of the processing liquid 3. Specifically, the mixing ratio correction unit 6 mixes the mixed liquid with the second phosphoric acid at a predetermined second mixing ratio (Q1:Q2) to prepare the processing liquid 3. The mixing ratio correction unit 6 manufactures a processing liquid containing both the mixed liquid and the second phosphoric acid as the processing liquid 3, or a processing liquid containing only the mixed liquid. The processing unit 7 processes the substrate 2 with the processing liquid 3.

[0057] The mixing unit 5 includes a mixing tank 51, a first phosphoric acid supply unit 52, and a first additive supply unit 53. The mixing tank 51 stores a mixed solution. The first phosphoric acid supply unit 52 supplies the first phosphoric acid to the mixing tank 51. The first phosphoric acid is supplied, for example, in the form of an aqueous solution. The first additive supply unit 53 supplies a silicon oxide precipitation inhibitor to the mixing tank 51. The silicon oxide precipitation inhibitor is supplied, for example, in the form of an aqueous solution.

[0058] The first additive supply unit 53 includes, for example, a metering tank 53a, a first pump 53b, and a second pump 53c. The metering tank 53a stores a silica precipitation inhibitor. The first pump 53b is used to supply the silica precipitation inhibitor to the metering tank 53a. The second pump 53c is used to take out a predetermined amount V of the silica precipitation inhibitor from the metering tank 53a and deliver it to the mixing tank 51. By changing the number of supplies N, the first mixing ratio (M:N) can be changed. The supply amount V×M of the first phosphoric acid to the mixing tank 51 is fixed, and the supply amount V×N of the silica precipitation inhibitor to the mixing tank 51 is variable. In addition, the pressurized delivery of the silica precipitation inhibitor may be N 2 Pressurized delivery.

[0059] The mixing unit 5 may have a circulation line 54, and the circulation line 54 returns the mixed liquid taken out from the mixing tank 51 to the mixing tank 51. In addition, the mixing unit 5 may have a circulation pump 55 and a circulation filter 56 in the middle of the circulation line 54. The circulation pump 55 is used to pressurize and transport the mixed liquid. The circulation filter 56 is used to capture particles contained in the mixed liquid.

[0060] The mixing section 5 may have a direction switching valve 57 in the middle of the circulation line 54. The direction switching valve 57 switches the flow direction of the mixed liquid to a first direction returning to the mixing tank 51 or a second direction sent to the mixing ratio correction section 6. Both the flow in the first direction and the flow in the second direction can be formed by the circulation pump 55, and the number of pumps can be reduced.

[0061] The mixing unit 5 may include a drain 58 that discharges the mixed liquid from the mixing tank 51 to the outside of the substrate processing apparatus 1. When the first mixing ratio (M:N) is to be changed, the mixed liquid of the old first mixing ratio (M:N) is discharged from the mixing tank 51, and then a new mixed liquid of the first mixing ratio (M:N) is prepared in the mixing tank 51.

[0062] The mixing unit 5 may include a residual liquid measuring unit 59 for measuring the amount of the mixed liquid remaining in the mixing tank 51. If the amount of the residual liquid is measured, the mixed liquid can be replenished to the mixing tank 51 at an appropriate time before the mixing tank 51 becomes empty.

[0063] The mixing section 5 may include a plurality of mixing tanks 51. The details will be described later. By alternating the functions of the plurality of mixing tanks 51, it is possible to prevent the plurality of mixing tanks 51 from being emptied at the same time, and to prevent the interruption of the processing of the substrate 2 due to insufficient mixed liquid. Furthermore, the processing of the substrate 2 can be continuously performed by using a mixing tank 51 with a small capacity.

[0064] The mixing ratio correction section 6 includes a liquid supply line 61 and a second phosphoric acid supply section 62. The liquid supply line 61 supplies the mixed liquid from the mixing section 5 to the treatment section 7. The second phosphoric acid supply section 62 supplies the second phosphoric acid in the middle of the liquid supply line 61. The second phosphoric acid is supplied, for example, in the form of an aqueous solution. The phosphoric acid concentration of the second phosphoric acid aqueous solution may be the same as or different from the phosphoric acid concentration of the first phosphoric acid aqueous solution. By supplying the second phosphoric acid, the silicon oxide precipitation inhibitor is diluted, and the treatment liquid 3 with a low ratio of the silicon oxide precipitation inhibitor can be manufactured.

[0065] The mixing ratio correction unit 6 includes a first flow meter 63 and a second flow meter 64. The first flow meter 63 measures the flow rate Q1 of the mixed solution before the mixed solution merges with the second phosphoric acid. The flow rate Q1 is the sum of the flow rate q1 of the silicon oxide precipitation inhibitor and the flow rate q2 of the first phosphoric acid (see Figure 2 The flow rate ratio (q2:q1) of the first phosphoric acid to the silicon oxide precipitation inhibitor is the same as the first mixing ratio (M:N). The second flow meter 64 measures the flow rate Q2 of the second phosphoric acid before the mixed liquid merges with the second phosphoric acid.

[0066] The mixing ratio correction unit 6 may include a buffer tank 65 in the middle of the liquid feeding line 61. The buffer tank 65 temporarily stores the mixed solution and the second phosphoric acid. By storing, uneven mixing of the mixed solution and the second phosphoric acid can be reduced, and the mixing ratio (q2+Q2:q1) of phosphoric acid and the silicon oxide precipitation inhibitor can be stabilized.

[0067] The mixing ratio correction unit 6 may have a circulation line 66 that returns the treatment liquid 3 taken out from the buffer tank 65 to the buffer tank 65. The mixing ratio correction unit 6 may have a circulation pump 67, a thermostat 68, and a circulation filter 69 in the middle of the circulation line 66. The circulation pump 67 is used to pressurize and transport the treatment liquid 3. The thermostat 68 is used to adjust the temperature of the treatment liquid 3. For example, the thermostat 68 includes a heater that heats the treatment liquid 3. The temperature of the treatment liquid 3 is set to, for example, the boiling point of the treatment liquid 3. In addition, the thermostat 68 may also include a cooler that cools the treatment liquid 3. The circulation filter 69 is used to capture particles contained in the treatment liquid 3.

[0068] The liquid delivery line 61 includes an upstream line 61a and a downstream line 61b. The upstream line 61a connects the plurality of mixing tanks 51 to the buffer tank 65, and the plurality of downstream lines 61b connects the buffer tank 65 to the plurality of treatment units 7. The plurality of downstream lines 61b deliver the mixed liquid to the plurality of treatment units 7 individually, so that the flow rate of the treatment liquid 3 can be changed for each treatment unit 7. Figure 1 The downstream line 61 b ​​shown corresponds to the individual pipe described in the claims. The plurality of downstream lines 61 b ​​extend individually from the circulation line 66 to the processing unit 7 , for example.

[0069] In addition, the mixing ratio correction unit 6 is as follows Figure 1 The buffer tank 65 is shown, but it can also be Fig.11 It is shown without the buffer tank 65 . Fig.11 The second phosphoric acid supply unit 62 shown supplies the second phosphoric acid at the connection point between the upstream line 61a and the downstream line 61b. The second phosphoric acid flows along the downstream line 61b together with the first phosphoric acid and the silicon oxide precipitation inhibitor. The downstream line 61b branches from the middle and extends to a plurality of treatment units 7.

[0070] Figure 4 This is a diagram showing a processing unit according to one embodiment. Figure 4 In the diagram, the X-axis direction, the Y-axis direction, and the Z-axis direction are mutually perpendicular directions. The X-axis direction and the Y-axis direction are horizontal directions, and the Z-axis direction is a vertical direction.

[0071] The processing unit 7 is a batch system for processing a plurality of substrates 2 simultaneously with the processing liquid 3, and has a processing tank 71. The processing tank 71 stores the processing liquid 3, and the plurality of substrates 2 are immersed in the processing liquid 3 in the processing tank 71 and processed by the processing liquid 3.

[0072] The processing tank 71 is, for example, a double tank having an inner tank 71a for storing the processing liquid 3 and an outer tank 71b for collecting the processing liquid 3 overflowing from the inner tank 71a. The plurality of substrates 2 are immersed in the processing liquid 3 in the inner tank 71a and processed by the processing liquid 3.

[0073] The processing section 7 has a circulation line 72, and the circulation line 72 sends the processing liquid 3 taken out from the outer tank 71b to the inner tank 71a. In addition, the processing section 7 has a circulation pump 73, a thermostat 74 and a circulation filter 75 in the middle of the circulation line 72. The circulation pump 73 is used to pressurize and transport the processing liquid 3. The thermostat 74 is used to adjust the temperature of the processing liquid 3. For example, the thermostat 74 includes a heater for heating the processing liquid 3. The temperature of the processing liquid 3 is set to, for example, the boiling point of the processing liquid 3. In addition, the thermostat 74 may also include a cooler for cooling the processing liquid 3. The circulation filter 75 is used to capture particles contained in the processing liquid 3.

[0074] The processing unit 7 has a horizontal pipe 76 inside the inner tank 71a, and the horizontal pipe 76 supplies the processing liquid 3 sent from the circulation line 72 to the inside of the inner tank 71a. The horizontal pipe 76 extends in the X-axis direction, and a plurality of horizontal pipes 76 are provided at intervals in the Y-axis direction. The plurality of horizontal pipes 76 have a plurality of discharge ports at intervals in the long side direction thereof, and the plurality of discharge ports discharge the processing liquid 3 toward the top. Thus, a curtain-like upward flow can be formed inside the inner tank 71a.

[0075] The processing section 7 has a substrate holding section 77, which holds a plurality of substrates 2 at intervals in the X-axis direction and moves up and down between a standby position and a processing position. The standby position is a position for delivering a plurality of substrates 2 to a conveying device (not shown), and is arranged above the processing position. The processing position is a position for immersing a plurality of substrates 2 in a processing liquid 3. The substrate holding section 77 receives a substrate 2 before processing from the conveying device at the standby position, then descends to the processing position, and rises to the standby position again after a predetermined time, and transfers the processed substrate 2 to the conveying device at the standby position. Then, the same action is repeated.

[0076] During the processing of the substrate 2, since the silicon nitride film 23 is etched, silicon is gradually dissolved from the substrate 2. Therefore, in order to maintain the silicon concentration within the allowable range, during the processing of the substrate 2, the new processing liquid 3 and the old processing liquid 3 are exchanged, that is, the new processing liquid 3 is supplied and the old processing liquid 3 is discharged.

[0077] The processing section 7 includes a liquid supply section 78, and the liquid supply section 78 introduces new processing liquid 3 from the mixing ratio correction section 6 into the processing section 7. The liquid supply section 78 includes, for example, an on-off valve and a flow controller, and when the on-off valve is opened, new processing liquid 3 is supplied to the processing section 7. The supply amount is controlled by the flow controller.

[0078] In addition, the processing section 7 has a drain section 79 that discharges the old processing liquid 3 from the processing section 7. The drain section 79 has, for example, an on-off valve and a flow controller, and when the on-off valve is opened, the old processing liquid 3 is discharged from the processing section 7. The discharge amount is controlled by the flow controller.

[0079] During the processing of the substrate 2, the flow rate Q3 (L / min) of the new processing liquid 3 supplied to the processing unit 7 can be equal to the flow rate Q3 (L / min) of the old processing liquid 3 discharged from the processing unit 7. Since the new processing liquid 3 and the old processing liquid 3 are exchanged in equal amounts, the liquid volume of the processing tank 71 can be maintained constant.

[0080] The silicon concentration of the new treatment liquid 3 is lower than the target concentration (volume %), for example, zero. On the other hand, the silicon concentration of the old treatment liquid 3 is, for example, the target concentration. The product of the difference between the silicon concentrations of the new treatment liquid 3 and the old treatment liquid 3 and the flow rate Q3 is the flow rate of silicon discharged from the treatment unit 7. The flow rate is equal to the flow rate of silicon eluted from the substrate 2 in the treatment unit 7. As a result, the silicon concentration of the treatment liquid 3 can be maintained within an allowable range.

[0081] The processing unit 7 includes a second additive supply unit 80, which supplies a silicon concentration adjuster to the processing tank 71. The silicon concentration adjuster is an additive for adjusting the silicon concentration of the processing liquid 3. The silicon concentration adjuster is a general adjuster such as a silicon compound. The silicon concentration adjuster is supplied in the form of an aqueous solution.

[0082] The second additive supplying unit 80 supplies the silicon concentration adjusting agent to the processing tank 71, for example, after supplying the new processing liquid 3 to the empty processing tank 71 and before processing the substrate 2 with the new processing liquid 3. This is because the silicon concentration of the new processing liquid 3 is lower than the target concentration as described above. By supplying the silicon concentration adjusting agent to the processing tank 71, the silicon concentration of the processing liquid 3 can be increased to the target concentration, and the selectivity can be improved.

[0083] The control unit 9 is, for example, a computer. Figure 1 The control unit 9 is shown as having a CPU (Central Processing Unit) 91 and a storage medium 92 such as a memory. The storage medium 92 stores a program for controlling various processes performed in the substrate processing device 1. The control unit 9 controls the operation of the substrate processing device 1 by causing the CPU 91 to execute the program stored in the storage medium 92. In addition, the control unit 9 has an input interface 93 and an output interface 94. The control unit 9 receives signals from the outside using the input interface 93 and sends signals to the outside using the output interface 94.

[0084] The above-mentioned program is stored in, for example, a computer-readable storage medium, and is installed from the storage medium to the storage medium 92 of the control unit 9. Examples of the computer-readable storage medium include a hard disk (HD), a floppy disk (FD), a compact disk (CD), a magneto-optical disk (MO), a memory card, etc. In addition, the program may be downloaded from a server via a network and installed to the storage medium 92 of the control unit 9.

[0085] Figure 5 FIG. 2 is a diagram showing the operation of a substrate processing apparatus according to an embodiment of the present invention. Figure 5 As shown, the plurality of processing units 7 maintain the silicon concentration while processing the substrate 2. The silicon concentration maintenance includes exchanging the new processing liquid 3 with the old processing liquid 3, that is, supplying the new processing liquid 3 and discharging the old processing liquid 3.

[0086] In order to supply new treatment liquid 3 to the plurality of treatment parts 7, the mixing part 5 takes out the prepared mixed liquid from a mixing tank 51 and delivers it to the treatment parts 7. In addition, in order to supply new treatment liquid 3 to the treatment parts 7, the second phosphoric acid supply part 62 supplies the second phosphoric acid in the middle of the liquid delivery line 61. The second phosphoric acid, the first phosphoric acid and the silicon oxide precipitation inhibitor are mixed in the middle of the liquid delivery line 61 and delivered to the treatment parts 7 as the treatment liquid 3.

[0087] While the mixing unit 5 takes out the prepared mixed solution from one mixing tank 51 and transfers it to the processing unit 7, it prepares the mixed solution in another mixing tank 51. Since the functions of the plurality of mixing tanks 51 are alternated, it is possible to prevent the plurality of mixing tanks 51 from being emptied at the same time, and it is possible to prevent the interruption of the processing of the substrate 2 due to the shortage of the mixed solution. In addition, the processing of the substrate 2 can be continuously performed by using the mixing tank 51 with a small capacity.

[0088] In addition, the mixing unit 5 switches the mixing tank to be used for delivering the prepared mixed solution to the processing unit 7 in a predetermined order among the plurality of mixing tanks 51. Since the functions of the plurality of mixing tanks 51 are alternated, it is possible to prevent the plurality of mixing tanks 51 from being emptied at the same time, and to prevent the interruption of the processing of the substrate 2 due to the shortage of the mixed solution. Furthermore, the processing of the substrate 2 can be continuously performed by using the mixing tank 51 with a small capacity.

[0089] Figure 6 FIG. 1 is a flow chart showing the preparation of a mixed solution according to an embodiment of the present invention. When the control unit 9 receives a mixed solution preparation instruction, the control unit 9 executes Figure 6 The mixed liquid preparation instruction is generated when the amount of the mixed liquid remaining in the mixing tank 51 is lower than the threshold value. The mixed liquid preparation instruction is also generated when the first mixing ratio (M:N) is changed. The control unit 9 first determines the first mixing ratio (M:N) based on the pattern 27 of the substrate 2, etc. (S101).

[0090] The optimum value of the mixing ratio of the raw materials of the processing liquid 3, for example, the mixing ratio of phosphoric acid and the silicon oxide precipitation inhibitor, is different for each pattern 27. Therefore, for each pattern 27, the mixing ratio of the raw materials of the processing liquid 3 is determined in advance by experiments or the like and is stored in advance in the storage medium 92. In the following, the mixing ratio of the raw materials of the processing liquid 3 is expressed as a fixed ratio M of phosphoric acid.

[0091] The mixing ratio of the raw materials of the processing liquid 3 may also depend on processing conditions other than the pattern 27. The processing conditions include: (1) conditions that can be changed by the user of the substrate processing apparatus 1, that is, conditions that the user inputs into the control unit 9; (2) conditions that cannot be changed by the user of the substrate processing apparatus 1, that is, conditions determined by the structure of the substrate processing apparatus 1. (1) Conditions that can be input into the control unit 9 by the user include, for example, the processing time of the substrate 2 and the number of substrates 2 per batch other than the pattern 27 of the substrate 2; (2) Conditions determined by the structure of the substrate processing apparatus 1 include, for example, the capacity of the processing tank 71, the number of the processing tanks 71, the capacity of the mixing tank 51, the number of the mixing tanks 51, and the maximum flow rate of the liquid supply line 61. The maximum flow rate of the liquid supply line 61 is determined by, for example, the length and diameter of the piping.

[0092] The mixing ratio of phosphoric acid and the silicon oxide inhibitor may also depend on the processing conditions of the substrate 2 other than the pattern 27 of the substrate 2 as described above. Therefore, for each processing condition of the substrate 2, the mixing ratio of the raw materials of the processing liquid 3 is determined in advance by experiments or the like, and is stored in advance in the storage medium 92. In this case, the control unit 9 determines the first mixing ratio (M:N) based on the processing conditions of the substrate 2 (S101).

[0093] Specifically, the control unit 9 determines the mixing ratio with the highest ratio of the silicon oxide precipitation inhibitor from among the plurality of mixing ratios stored in advance as the first mixing ratio (M:N). This is because the ratio of the silicon oxide precipitation inhibitor can be reduced by supplying the second phosphoric acid as described later. By determining the mixing ratio with the highest ratio as the first mixing ratio (M:N), it is not necessary to frequently change the first mixing ratio (M:N), and the amount of waste of the mixed solution can be reduced.

[0094] However, in order to manufacture a new generation of semiconductor devices, when the pattern 27 of the substrate 2 is updated, for example, when the number of stacked films 24 is increased, the maximum value of the silicon concentration becomes higher as described above, and therefore the optimal ratio of the silicon oxide precipitation inhibitor becomes higher. In this case, the optimal mixing ratio is re-determined by experiments, etc., and is re-stored in the storage medium 92. The mixing ratio of phosphoric acid and the silicon oxide precipitation inhibitor is also a condition that can be input into the control unit 9 by the user.

[0095] As described above, the control unit 9 determines the first mixing ratio (M:N) based on the pattern 27 of the substrate 2 (S101). In addition, the control unit 9 determines the mixing ratio with the highest ratio of the silicon oxide precipitation inhibitor from the plurality of mixing ratios stored in advance as the first mixing ratio (M:N). By appropriately updating the first mixing ratio (M:N), a new generation of semiconductor devices can be manufactured, and the life of the substrate processing apparatus 1 can be prevented from ending due to the replacement of semiconductor devices.

[0096] After the first mixing ratio (M:N) is determined (S101), the control unit 9 performs draining from the mixing tank 51 (S102). When the first mixing ratio (M:N) is to be changed, draining is performed until there is no mixed liquid of the old first mixing ratio (M:N). On the other hand, when the first mixing ratio (M:N) is not to be changed, draining is performed to such an extent that V×M(L) of the first phosphoric acid and V×N(L) of the silicon oxide precipitation inhibitor can be supplied to the mixing tank 51 thereafter. After draining the mixing tank 51 (S102), the control unit 9 supplies V×M(L) of the first phosphoric acid to the mixing tank 51 (S103).

[0097] The control unit 9 performs metering (S104) of at least a portion of the silicon oxide precipitation inhibitor during the discharge (S102) from the mixing tank 51. The metering (S104) of the silicon oxide precipitation inhibitor includes injecting the silicon oxide precipitation inhibitor into the metering tank 53a. Since the discharge (S102) of the mixing tank 51 and the metering (S104) of at least a portion of the silicon oxide precipitation inhibitor are performed simultaneously, the time spent on the preparation of the mixed solution can be reduced.

[0098] After the silicon oxide precipitation inhibitor is measured (S104), the control unit 9 takes out V (L) of silicon oxide precipitation inhibitor from the measuring tank 53a and supplies it to the mixing tank 51 (S105). Then, the control unit 9 checks the cumulative supply times (S106). When the supply times are less than N times (S106, No), since the supply amount of the silicon oxide precipitation inhibitor is insufficient, the control unit 9 returns to S104 and repeats the processing after S104. On the other hand, when the supply times are N times (S106, Yes), since V×N (L) of silicon oxide precipitation inhibitor is supplied, the control unit 9 ends this processing.

[0099] In addition, the control unit 9 may start the circulation of the mixed solution after the discharge from the mixing tank 51 is completed (S102). By circulating the mixed solution, uneven mixing can be reduced. The circulation of the mixed solution can be implemented from the completion of the supply of the first phosphoric acid and the silicon oxide precipitation inhibitor until a predetermined time has passed. Particles contained in the mixed solution can be removed.

[0100] Figure 7 : is a graph showing the relationship between the first mixing ratio (M:N) and the number of supply times N according to one embodiment. Figure 7 As shown, the control unit 9 controls the supply count N and controls the first mixing ratio (M:N). Since V×M(L) is fixed, the control unit 9 controls V×N(L) and controls the first mixing ratio (M:N).

[0101] Figure 8FIG. 1 is a flow chart showing a method of supplying a mixed solution to a processing unit according to an embodiment of the present invention. Figure 8 The supply command is generated, for example, when the processing of the substrate 2 is started. During the processing of the substrate 2, the new processing liquid 3 and the old processing liquid 3 are exchanged to maintain the silicon concentration.

[0102] When the substrate 2 is processed in a batch mode, even when the mixing ratio of the raw materials of the processing liquid 3, for example, the mixing ratio of phosphoric acid (first phosphoric acid and second phosphoric acid) and the silicon oxide precipitation inhibitor is changed, a supply instruction is generated and the processing liquid 3 of the new mixing ratio is stored in the processing tank 71. In this case, before the processing liquid 3 of the new mixing ratio is stored in the processing tank 71, the processing liquid 3 of the old mixing ratio is discharged from the processing tank 71.

[0103] The control unit 9 first determines the mixing ratio of the raw materials of the processing liquid 3 based on the pattern 27 of the substrate 2 processed by the processing liquid 3, and determines the second mixing ratio (Q1:Q2) (S201) to achieve the determined mixing ratio. Figure 2 The figure shows the sum of the flow rate q1 of the silicon oxide precipitation inhibitor and the flow rate q2 of the first phosphoric acid. The flow rate ratio (q2:q1) of the first phosphoric acid to the silicon oxide precipitation inhibitor is the same as the first mixing ratio (M:N).

[0104] Fig. 9 : is a graph showing the relationship between the mixing ratio of the raw materials of the treatment liquid and the second mixing ratio (Q2:Q1) according to one embodiment. Fig. 9 As shown, Q2 / Q1 increases, and the ratio of the silicon oxide precipitation inhibitor relatively decreases as Q2 / q2 increases.

[0105] Furthermore, the mixing ratio of the raw materials of the processing liquid 3 also depends on the processing conditions of the substrate 2 other than the pattern 27 of the substrate 2 as described above, and therefore can be determined based on other processing conditions.

[0106] After the second mixing ratio (Q1:Q2) is determined, the control unit 9 determines Q1 and Q2 respectively (S202). Q1 and Q2 are determined according to the purpose of the supply instruction. First, refer to Fig.10 , illustrating a situation where the purpose of supplying instructions is to maintain the silicon concentration during the processing of substrate 2.

[0107] Fig.10 : is a graph showing the relationship between the number of substrates per batch and the sum of Q1 and Q2 (Q1+Q2) in one embodiment. Since the flow rate of silicon eluted from substrate 2 is proportional to the number of substrates 2, Q1+Q2 is proportional to Fig.10 The number of substrates 2 shown is proportional.

[0108] On the other hand, when the purpose of the supply instruction is to store the treatment liquid 3 of the new mixing ratio in the treatment tank 71, in order to shorten the storage time, Q1+Q2 may be the maximum flow rate of the liquid supply line 61. The maximum flow rate of the liquid supply line 61 is determined by the length or diameter of the pipe as described above.

[0109] like Figure 8 As shown, the control unit 9 checks whether Q2 is zero (S203). Since the supply of the second phosphoric acid is not required when Q2 is zero (S203, yes), the control unit 9 supplies only the mixed solution to the processing unit 7 (S204). On the other hand, when Q2 is not zero (S203, no), the control unit 9 supplies the mixed solution and the second phosphoric acid to the processing unit 7 (S205).

[0110] The supply of the mixed solution ( S204 ) or the supply of the mixed solution and the second phosphoric acid ( S205 ) is performed until the purpose of the supply instruction is achieved. Then, the control unit 9 ends the current processing.

[0111] The above describes the embodiments of the substrate processing device and the substrate processing method of the present invention, but the present invention is not limited to the above embodiments, etc. Various changes, modifications, substitutions, additions, deletions and combinations can be made within the scope of the claims. These certainly belong to the technical scope of the present invention.

[0112] The control unit 9 of the above embodiment controls the mixing ratio of phosphoric acid and the silicon oxide precipitation inhibitor, but the type of additive is not limited to the silicon oxide precipitation inhibitor. For example, the control unit 9 may control the mixing ratio of phosphoric acid and the silicon concentration regulator. In this case, the first additive supply unit 53 supplies the silicon concentration regulator to the mixing tank 51 as an additive.

[0113] The mixing ratio of phosphoric acid to the silicon concentration adjusting agent, like the mixing ratio of phosphoric acid to the silicon oxide precipitation inhibitor, also has different optimum values ​​for the processing conditions for each substrate 2. For example, as the number of stacked films 24 increases, the maximum value of the silicon concentration becomes higher as described above, so the optimum ratio of the silicon oxide concentration adjusting agent decreases. Furthermore, as the number of substrates 2 per batch increases, the flow rate of silicon eluted from the substrate 2 increases, the maximum value of the silicon concentration becomes higher, and thus the optimum ratio of the silicon oxide concentration adjusting agent becomes lower.

[0114] Therefore, the mixing ratio of phosphoric acid and silicon concentration adjusting agent is also determined in advance by experiments or the like for the processing conditions of each substrate 2, and is stored in advance in the storage medium 92. The control unit 9 determines the mixing ratio with the highest ratio of silicon concentration adjusting agent from the plurality of pre-stored mixing ratios as the first mixing ratio (M:N). This is because the ratio of silicon concentration adjusting agent can be reduced by supplying the second phosphoric acid. Since the mixing ratio with the highest ratio is determined as the first mixing ratio (M:N), the amount of waste of the mixed solution can be reduced without frequently changing the first mixing ratio (M:N).

[0115] In addition, the substrate 2 in the above embodiment includes the silicon wafer 21, the silicon oxide film 22 and the silicon nitride film 23, but the structure of the substrate 2 is not particularly limited. For example, the substrate 2 may include a silicon carbide substrate, a gallium oxide substrate or a gallium nitride substrate instead of the silicon wafer 21.

[0116] In addition, the processing unit 7 of the above embodiment may be a batch type, but may also be a single-chip type. The single-chip type processing unit 7, for example, includes a rotating chuck, a nozzle, and a cup body. The rotating chuck rotates while holding the substrate. The nozzle supplies the processing liquid 3 to the substrate 2 rotating together with the rotating chuck. The processing liquid 3 is supplied to the center of the substrate 2, and wets and spreads radially outward of the substrate 2 due to the centrifugal force. The cup body is used to recover the processing liquid 3 scattered from the periphery of the substrate 2.

Claims

1. A substrate processing device, characterized in that: have: a processing portion for treating the substrate with a processing liquid; a mixing unit for mixing the first phosphoric acid and the silicon oxide precipitation inhibitor as raw materials of the treatment liquid at a predetermined mixing ratio to prepare a mixed liquid; a mixing ratio correction section that corrects the mixing ratio of the raw materials of the treatment liquid, comprising a liquid supply line that supplies the mixed liquid from the mixing section to the treatment section and a second phosphoric acid supply section that supplies second phosphoric acid in the middle of the liquid supply line; and a control unit that controls a first mixing ratio of the first phosphoric acid to the silicon oxide precipitation inhibitor and a second mixing ratio of the mixed solution to the second phosphoric acid, The mixing unit comprises: a mixing tank for storing the mixed liquid; a first phosphoric acid supply unit for supplying the first phosphoric acid to the mixing tank; and a silicon oxide precipitation inhibitor supply unit for supplying the silicon oxide precipitation inhibitor to the mixing tank, The control unit changes the concentration of the silicon oxide precipitation inhibitor contained in the processing liquid supplied onto the substrate in the processing unit by changing at least one of the first mixing ratio and the second mixing ratio based on the processing conditions of the substrate.

2. The substrate processing device according to claim 1, characterized in that: The processing condition of the substrate is a pattern of the substrate to be processed with the processing liquid.

3. The substrate processing device according to claim 1 or 2, characterized in that: The mixing unit includes a plurality of mixing tanks.

4. The substrate processing device according to claim 3, characterized in that: The control unit mixes the mixed liquid in the other mixing tank while the mixed liquid is taken out from one mixing tank and sent to the processing unit.

5. The substrate processing device according to claim 3, characterized in that: The control unit switches the mixing tank that is to send the prepared mixed liquid to the processing unit among the plurality of mixing tanks in a predetermined order.

6. The substrate processing device according to claim 1 or 2, characterized in that: The processing unit is provided with a plurality of The liquid supply line includes individual pipes for individually supplying the mixed liquid to the plurality of processing units.

7. The substrate processing device according to claim 1 or 2, characterized in that: The mixing ratio correction unit includes a buffer tank temporarily storing the mixed liquid and the second phosphoric acid in the middle of the liquid feeding line.

8. The substrate processing device according to claim 7, characterized in that: The mixing ratio correction unit includes a circulation line that returns the treatment liquid taken out from the buffer tank to the buffer tank.

9. A substrate processing method, characterized in that: include: A step of mixing a first phosphoric acid and a silicon oxide precipitation inhibitor as raw materials of a treatment liquid in a predetermined first mixing ratio to prepare a mixed liquid; The step of mixing the mixed solution with a second phosphoric acid at a predetermined second mixing ratio to correct the mixing ratio of the raw materials of the treatment solution; and The step of treating the substrate with the treatment liquid, In the substrate processing method, the concentration of the silicon oxide precipitation inhibitor contained in the processing liquid supplied onto the substrate is changed by changing at least one of the first mixing ratio and the second mixing ratio based on the processing conditions of the substrate.

10. The substrate processing method according to claim 9, characterized in that: The processing condition of the substrate is a pattern of the substrate to be processed with the processing liquid.

11. The substrate processing method according to claim 9 or 10, characterized in that: The method comprises the step of preparing the mixed liquid in another mixing tank while the mixed liquid is taken out from one mixing tank and transported to a processing section for processing the substrate.

12. The substrate processing method according to claim 9 or 10, characterized in that: The method includes the step of switching a mixing tank among a plurality of mixing tanks in a predetermined order to deliver the prepared mixed liquid to a processing unit that processes the substrate.

13. The substrate processing method according to claim 9 or 10, characterized in that: The substrate includes a laminated film having silicon oxide films and silicon nitride films alternately, The laminate film has an opening that penetrates the laminate film in a thickness direction. The processing liquid selectively etches the silicon nitride film among the silicon oxide film and the silicon nitride film.

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