Etching solution management system, etching solution management method, and program

Abstract

To provide an etching solution management system that can increase the rate at which desired etching results are obtained compared to conventional systems.SOLUTION: An etching solution management system includes: a flow rate acquisition unit that acquires flow rate information indicating the flow rate of an etching solution in each of a plurality of openings for a resist; a state acquisition unit that acquires solution state information indicating the state of the etching solution; an etching estimation unit that estimates the etching depth in each of the plurality of openings using at least the solution state information, the flow rate information, and shape information indicating the shape of each of the plurality of openings; an evaluation unit that evaluates the etching results when an etching solution corresponding to the solution state information is used, based on the etching depth in each of the plurality of openings estimated by the etching estimation unit; and an etching solution adjustment unit that determines adjustment instructions for the etching solution based at least on the evaluation by the evaluation unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an etching liquid management system, an etching liquid management method, and a program. [Background technology]

[0002] Wet etching is a processing method in which the portions (openings) of an etching substrate, such as copper, that are not covered with resist are corroded with an etching solution to form the substrate into a desired shape. Etching solutions are sometimes used repeatedly, but the corroded substrate dissolves in the etching solution, causing the composition to change with use. For this reason, Patent Document 1 discloses a chemical solution management system that maintains chemical solutions, such as etching solutions, at a predetermined concentration. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-200942 Summary of the Invention [Problem to be solved by the invention]

[0004] However, a chemical management system that maintains a predetermined concentration has the problem that desired etching results may not be obtained.

[0005] The present invention has been made in view of the above circumstances, and provides an etching solution management system, an etching solution management method, and a program that can increase the rate at which desired etching results are obtained compared to conventional systems. [Means for solving the problem]

[0006] The present invention has been made to solve the above-mentioned problems, and one aspect of the present invention is an etching liquid management system comprising: a flow rate acquisition unit that acquires flow rate information indicating the flow rate of an etching liquid in each of a plurality of openings in a resist; a state acquisition unit that acquires liquid state information indicating the state of the etching liquid; an etching estimation unit that estimates the etching depth in each of the plurality of openings using at least the liquid state information acquired by the state acquisition unit, the flow rate information acquired by the flow rate acquisition unit, and shape information indicating the shape of each of the plurality of openings; an evaluation unit that evaluates the etching results when an etching liquid corresponding to the liquid state information is used, based on the etching depth in each of the plurality of openings estimated by the etching estimation unit; and an etching liquid adjustment unit that determines adjustment instructions for the etching liquid based at least on the evaluation by the evaluation unit.

[0007] Another aspect of the present invention is the etching liquid management system described above, wherein the liquid state information includes at least any one of an ORP (Oxidation-Reduction Potential) value, a temperature, and a concentration of the etching liquid.

[0008] Another aspect of the present invention is the etching liquid management system described above, wherein the shape information includes at least one of an opening width and a resist thickness of each of the plurality of openings.

[0009] Another aspect of the present invention is the etching liquid management system described above, wherein the flow rate information is a flow rate vector.

[0010] Another aspect of the present invention is the etching solution management system described above, wherein the evaluation unit evaluates the etching result based on a feature related to the distribution of the etching depth among the plurality of openings.

[0011] Another aspect of the present invention is an etching liquid management method comprising: a first step of acquiring flow rate information indicating the flow rate of an etching liquid in each of a plurality of openings in a resist; a second step of acquiring liquid state information indicating the state of the etching liquid; a third step of estimating an etching depth in each of the plurality of openings using at least the liquid state information acquired in the second step, the flow rate information acquired in the first step, and shape information indicating the shape of each of the plurality of openings; a fourth step of evaluating, based on the etching depth in each of the plurality of openings estimated in the third step, an etching result when an etching liquid corresponding to the liquid state information is used; and a fifth step of determining adjustment instructions for the etching liquid based at least on the evaluation in the fourth step.

[0012] Another aspect of the present invention is a program for causing a computer to function as: a flow rate acquisition unit that acquires flow rate information indicating the flow rate of an etching liquid in each of a plurality of openings in a resist; a state acquisition unit that acquires liquid state information indicating the state of the etching liquid; an etching estimation unit that estimates the etching depth in each of the plurality of openings using at least the liquid state information acquired by the state acquisition unit, the flow rate information acquired by the flow rate acquisition unit, and shape information indicating the shape of each of the plurality of openings; an evaluation unit that evaluates an etching result when an etching liquid corresponding to the liquid state information is used, based on the etching depth in each of the plurality of openings estimated by the etching estimation unit; and an etching liquid adjustment unit that determines adjustment instructions for the etching liquid, based at least on the evaluation by the evaluation unit. [Effects of the Invention]

[0013] According to the present invention, the rate at which desired etching results are obtained can be increased compared to the conventional case. [Brief explanation of the drawings]

[0014] [Figure 1]1 is a schematic block diagram showing the configuration of a wet etching system 100 according to an embodiment of the present invention. [Figure 2] 2 is a schematic block diagram showing the functional configuration of an etching liquid management system 60 in the same embodiment. FIG. [Figure 3] 10A and 10B are diagrams showing examples of simulation results by an etching simulator 61 in the same embodiment. [Figure 4] 10 is a flowchart illustrating an example of the operation of the etching liquid management system 60 in the embodiment. [Figure 5] 10 is a flowchart illustrating an example of the operation of an etching estimation unit 66 in the embodiment. [Figure 6] FIG. 10 is a schematic block diagram showing the functional configuration of an etching liquid management system 60a according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram showing the configuration of a wet etching system 100 according to one embodiment of the present invention. The wet etching system 100 performs wet etching by repeatedly adjusting the etching solution. In this embodiment, the wet etching system 100 uses an aqueous solution of iron (III) chloride as the etching solution to corrode and etch copper, which is the etching substrate, but other etching solutions (e.g., aqua regia, hydrofluoric acid, etc.) or etching substrates (e.g., other metals, glass, semiconductors, etc.) may also be used.

[0016] The wet etching system 100 includes a wet etching apparatus 10, an adjustment tank 20, a water tank 30, a hydrochloric acid tank 40, an iron liquid tank 50, and an etching solution management system 60. The wet etching apparatus 10 performs wet etching using the etching solution supplied from the adjustment tank 20, and returns the used etching solution to the adjustment tank 20.

[0017] The adjustment tank 20 stores the etching solution and supplies it to the wet etching apparatus 10. The adjustment tank 20 is also supplied with the etching solution used in the wet etching apparatus 10, water from the water tank 30, hydrochloric acid from the hydrochloric acid tank 40, and iron solution (iron (III) chloride solution, ferric chloride solution) from the iron solution tank 50. A portion of the etching solution stored in the adjustment tank 20 is discarded as waste liquid. The amounts of water from the water tank 30, hydrochloric acid from the hydrochloric acid tank 40, and iron solution from the iron solution tank 50 supplied to the adjustment tank 20, as well as the amount of waste liquid, are controlled by adjustment instructions from the etching solution management system 60.

[0018] The water tank 30 stores water and supplies water to the adjustment tank 20 in accordance with adjustment instructions from the etching solution management system 60. The hydrochloric acid tank 40 stores hydrochloric acid and supplies hydrochloric acid to the adjustment tank 20 in accordance with adjustment instructions from the etching solution management system 60. The iron liquid tank 50 stores iron liquid and supplies iron liquid to the adjustment tank 20 in accordance with adjustment instructions from the etching solution management system 60.

[0019] The etching solution management system 60 acquires liquid state information indicating the state of the etching solution stored in the adjustment tank 20, and estimates the results of etching by the wet etching apparatus 10 based on the liquid state information. The etching solution management system 60 evaluates the estimation results, and controls the amounts of water from the water tank 30, hydrochloric acid from the hydrochloric acid tank 40, and iron solution from the iron solution tank 50 supplied to the adjustment tank 20, as well as the amount of waste solution from the adjustment tank 20, based at least on the evaluation results. The etching solution management system 60 may be realized by one or more computers reading and executing a program.

[0020] 2 is a schematic block diagram showing the functional configuration of an etching liquid management system 60 according to this embodiment. The etching liquid management system 60 includes an etching simulator 61, an etching prediction model generator 62, a state acquirer 63, a flow rate calculator 64, a memory 65, an etching estimation unit 66, an evaluator 67, and an etching liquid adjuster 68.

[0021] The etching simulator 61 performs a simulation (numerical simulation) of etching under a plurality of conditions. In this simulation, the progress of corrosion of an etching substrate (metal substrate) by an etching solution in a virtual opening in a resist is simulated. More specifically, the progress of corrosion of an etchant (Fe 3+ ) concentration distribution, the reaction between copper and etchant (FeCl3 + Cu → FeCl2 + CuCl), the dissolved copper (Cu + The concentration distribution of ) is simulated. Note that among the plurality of conditions, any one of the conditions relating to the shape of the opening, the conditions relating to the flow rate of the etching solution, and the conditions relating to the state of the etching solution is different.

[0022] The condition regarding the shape of the opening is given by shape information indicating the shape of the opening. The shape information may include at least a part of the opening width and the resist thickness. The condition regarding the flow rate of the etching liquid is given by flow rate information indicating the flow rate of the etching liquid. The flow rate information may include the absolute value of the flow rate of the etching liquid at the opening, the absolute value of the flow rate of the etching liquid in the opening width direction at the opening, the absolute value of the flow rate of the etching liquid in the depth direction at the opening, the absolute value of the flow rate of the etching liquid in directions perpendicular to both the opening width direction and the depth direction at the opening, and at least a part of the flow rate vector of the etching liquid at the opening. The condition regarding the state of the etching liquid is given by liquid state information indicating the state of the etching liquid. The liquid state information may include at least a part of the temperature, ORP (Oxidation-Reduction Potential) value, and iron concentration of the etching liquid. Here, the ORP value is a value indicating the proportion of etchant used in the etching liquid. In this embodiment, the Fe ions (Fe 3+ and Fe 2+ ) Fe 3+ It is a value that indicates the ratio of ions. It may also include information on the concentration and valence of the dissolved substance, and the concentration of hydrochloric acid.

[0023] The etching prediction model generation unit 62 generates an etching prediction model by machine learning using the simulation results from the etching simulation unit 61. This etching prediction model obtains the etching progress rate or the etching depth after a predetermined time from conditions related to the shape of the opening in the resist, conditions related to the flow rate of the etching solution, conditions related to the state of the etching solution, and the etching depth. Note that any method such as regression analysis or neural network may be used for the machine learning.

[0024] The status acquisition unit 63 acquires liquid status information indicating the status of the etching liquid stored in the adjustment tank 20. The flow rate calculation unit 64 (flow rate acquisition unit) acquires flow rate information indicating the flow rate of the etching liquid at each of the multiple openings in the resist. For example, the flow rate calculation unit 64 reads information indicating the shape of the substrate to be etched from the storage unit 65, and uses the information and information on the spray nozzle and liquid pressure prepared in advance to perform a numerical simulation of the flow of the etching liquid sprayed onto the substrate to be etched. This numerical simulation calculates the flow rate of the etching liquid at each opening in the resist on the substrate to be etched. The information indicating the shape of the substrate to be etched may include information such as the spray position of the etching liquid relative to the substrate to be etched and the position of the rollers of the wet etching apparatus 10 that transport the substrate to be etched.

[0025] The storage unit 65 stores information indicating the shape of the etching substrate to be etched by the wet etching device 10. The etching estimation unit 66 estimates the etching depth of each of the plurality of openings using at least the liquid state information acquired by the state acquisition unit 63, the flow rate information acquired by the flow rate calculation unit, and shape information indicating the shape of each of the plurality of openings in the resist. For this estimation, the etching prediction model generated by the etching prediction model generation unit 62 is used.

[0026] The evaluation unit 67 evaluates the etching results when an etching solution corresponding to the solution state information is used, based on the etching depths at each of the plurality of openings estimated by the etching estimation unit 66. For example, the evaluation unit 67 determines whether the average value of the etching depths among the plurality of openings is within a desired range, and if it is within the desired range, determines that the etching results are good, and if it is not within the desired range, determines that there is a problem with the etching results. Furthermore, the evaluation unit 67 may evaluate the etching results based on a feature value (e.g., 3σ) related to the distribution of the etching depths among the plurality of openings, in addition to the average value.

[0027] The etching liquid adjustment unit 68 determines adjustment instructions for the etching liquid based at least on the evaluation by the evaluation unit 67. If the evaluation unit 67 determines that the etching result is good, the etching liquid adjustment unit 68 does not need to adjust the etching liquid. Furthermore, if the evaluation unit 67 determines that the etching result is good, the etching liquid adjustment unit 68 may determine the amount of supply from the water tank 30, the hydrochloric acid tank 40, and the iron liquid tank 50, and the amount of waste liquid from the adjustment tank 20, so that the liquid state information of the etching liquid does not change.

[0028] Furthermore, if the evaluation unit 67 determines that there is a problem with the etching result, the etching solution adjustment unit 68 determines the amounts of supply from the water tank 30, the hydrochloric acid tank 40, and the iron solution tank 50, and the amount of waste solution from the adjustment tank 20, and issues adjustment instructions. Note that these amounts may be determined using the etching depth estimated by the etching estimation unit 66 or a feature quantity of the distribution of the depth. Furthermore, machine learning techniques such as regression analysis may be used to determine these amounts.

[0029] 3 is a diagram showing an example of a simulation result by the etching simulator 61 in this embodiment. FIG. 3 shows the Fe concentration in the etching solution at a certain time obtained by simulation for one opening. 3+In the example of Figure 3, a resist with a resist thickness of T is applied to an etching substrate, an opening in the resist with an opening width of W is formed, and corrosion has progressed to an etching depth of D.

[0030] 4 is a flowchart illustrating an example of the operation of the etching liquid management system 60 in this embodiment. First, the etching simulator 61 simulates etching in a virtual opening under a plurality of conditions (step Sa1). Next, the etching prediction model generator 62 generates an etching prediction model using the simulation results of step Sa1 (step Sa2). Next, the status acquirer 63 acquires liquid status information of the etching liquid stored in the adjustment tank 20 (step Sa3). Next, the flow rate calculator 64 calculates the flow rate of the etching liquid (step Sa4).

[0031] Next, the etching estimation unit 66 estimates the etching depth using the etching prediction model generated in step Sa2 (step Sa5). Next, the evaluation unit 67 evaluates the etching result based on the etching depth estimated in step Sa5 (step Sa6). If the evaluation by the evaluation unit 67 is good (step Sa7-Yes), the process is terminated. If the evaluation by the evaluation unit 67 is not good (step Sa7-No), the etching solution adjustment unit 68 issues instructions to the adjustment tank 20, the water tank 30, the hydrochloric acid tank 40, and the iron solution tank 50 to adjust the etching solution (step Sa8).

[0032] FIG. 5 is a flowchart illustrating an example of the operation of the etching estimation unit 66 in this embodiment. First, the etching estimation unit 66 sets initial values ​​for the time and etching depth (step Sb1). Next, the etching estimation unit 66 acquires flow velocity information at the set time from the flow velocity calculation unit 64 (step Sb2). Next, the etching estimation unit 66 uses the etching prediction model to estimate the etching depth a predetermined time t after the set time if the etching depth at the set time is the set depth (step Sb3). If the predetermined time t after the set time is past the end time (step Sb4—Yes), the etching estimation unit 66 ends the process. If the predetermined time t after the set time is not past the end time (step Sb4—No), the etching estimation unit 66 changes the set time to the predetermined time t later (step Sb5). Next, the etching estimation unit 66 sets the etching depth at the set time to the value estimated in step Sb3 (step Sb6) and returns to step Sb2.

[0033] In this way, the etching estimation unit 66 estimates the etching depth at every predetermined time t. That is, the etching prediction model is a model that uses the etching depth at a certain time as part of its input and predicts the etching depth a predetermined time t after that time.

[0034] Fig. 6 is a schematic block diagram showing the functional configuration of an etching liquid management system 60a according to a modified example of this embodiment. In Fig. 6, the same components as those in Fig. 2 are denoted by the same reference numerals, and their description will be omitted. The etching liquid management system 60a includes a state acquisition unit 63, a flow rate calculation unit 64, a storage unit 65, an etching estimation unit 66, an evaluation unit 67, an etching liquid adjustment unit 68, and a model storage unit 69. The model storage unit 69 stores an etching prediction model, and the etching estimation unit 66 estimates the etching depth using the etching prediction model stored in the model storage unit 69.

[0035] In the above-described embodiment and modified examples, the etching depth is estimated using the etching prediction model, and the etching result is evaluated based on the depth. However, in addition to the depth, at least one of the corner R, the side etching amount (etching width), and EF (Etching Factor) may be estimated, and the etching result may be evaluated based on the depth and at least one of the corner R, the side etching amount (etching width), and EF (Etching Factor).

[0036] As described above, the etching liquid management systems 60, 60a in the above-described embodiments and modifications include an etching estimation unit 66 that estimates the etching depth in each of the plurality of openings using at least the liquid state information, flow rate information, and shape information indicating the shape of each of the plurality of openings, an evaluation unit 67 that evaluates the etching results based on the etching depth estimated by the etching estimation unit 66, and an etching liquid adjustment unit 68 that determines adjustment instructions for the etching liquid based at least on the evaluation by the evaluation unit 67. This makes it possible to obtain a desired etching result at a higher rate than before.

[0037] The present invention may also be embodied as follows. (1) One embodiment of the present invention is an etching liquid management system comprising: a flow rate acquisition unit that acquires flow rate information indicating the flow rate of an etching liquid in each of a plurality of openings in a resist; a state acquisition unit that acquires liquid state information indicating the state of the etching liquid; an etching estimation unit that estimates the etching depth in each of the plurality of openings using at least the liquid state information acquired by the state acquisition unit, the flow rate information acquired by the flow rate acquisition unit, and shape information indicating the shape of each of the plurality of openings; an evaluation unit that evaluates the etching results when an etching liquid corresponding to the liquid state information is used, based on the etching depth in each of the plurality of openings estimated by the etching estimation unit; and an etching liquid adjustment unit that determines adjustment instructions for the etching liquid based at least on the evaluation by the evaluation unit.

[0038] (2) Another embodiment of the present invention is the etching liquid management system according to (1), wherein the liquid state information includes at least one of an ORP value, a temperature, and a concentration of the etching liquid.

[0039] (3) Another embodiment of the present invention is the etching solution management system according to (1) or (2), wherein the shape information includes at least one of the opening width and resist thickness of each of the plurality of openings.

[0040] (4) Another embodiment of the present invention is the etching liquid management system according to any one of (1) to (3), wherein the flow velocity information is a flow velocity vector.

[0041] (5) Another embodiment of the present invention is an etching solution management system according to any one of (1) to (4), wherein the evaluation unit evaluates the etching result based on a feature related to the distribution of the etching depth among the plurality of openings.

[0042] (6) Another embodiment of the present invention is an etching liquid management method including: a first step of acquiring flow rate information indicating the flow rate of the etching liquid in each of a plurality of openings in a resist; a second step of acquiring liquid state information indicating the state of the etching liquid; a third step of estimating the etching depth in each of the plurality of openings using at least the liquid state information acquired in the second step, the flow rate information acquired in the first step, and shape information indicating the shape of each of the plurality of openings; a fourth step of evaluating, based on the etching depth in each of the plurality of openings estimated in the third step, an etching result when an etching liquid corresponding to the liquid state information is used; and a fifth step of determining adjustment instructions for the etching liquid based at least on the evaluation in the fourth step.

[0043] (7) Another embodiment of the present invention is a program for causing a computer to function as: a flow rate acquisition unit that acquires flow rate information indicating the flow rate of an etching liquid in each of a plurality of openings in a resist; a state acquisition unit that acquires liquid state information indicating the state of the etching liquid; an etching estimation unit that estimates the etching depth in each of the plurality of openings using at least the liquid state information acquired by the state acquisition unit, the flow rate information acquired by the flow rate acquisition unit, and shape information indicating the shape of each of the plurality of openings; an evaluation unit that evaluates an etching result when an etching liquid corresponding to the liquid state information is used, based on the etching depth in each of the plurality of openings estimated by the etching estimation unit; and an etching liquid adjustment unit that determines adjustment instructions for the etching liquid, based at least on the evaluation by the evaluation unit.

[0044] 1, 2, and 6, a program for realizing the functions of the etching liquid management systems 60 and 60a may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed to realize the etching liquid management systems 60 and 60a. Note that the term "computer system" here includes hardware such as an OS and peripheral devices.

[0045] "Computer-readable recording media" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into computer systems. Furthermore, "computer-readable recording media" also includes devices that dynamically store programs for a short period of time, such as communication lines used when transmitting programs over networks like the Internet or over communication lines like telephone lines, and devices that store programs for a fixed period of time, such as volatile memory within computer systems that serve as servers or clients. The programs may also be programs that implement some of the aforementioned functions, or may be programs that can realize the aforementioned functions in combination with programs already stored in the computer system.

[0046] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present invention. [Explanation of symbols]

[0047] 10 Wet etching equipment 20 Adjustment Tank 30 Water Tank 40 Hydrochloric Acid Tank 50 Iron Liquid Tank 60, 60a Etching Solution Management System 61 Etching simulation section 62 Etching prediction model generation unit 63 Status acquisition unit 64 Flow velocity calculation section 65 Storage section 66 Etching Estimation Section 67 Evaluation Department 68 Etching solution adjustment section 100 Wet Etching System

Claims

1. a flow rate acquiring unit that acquires flow rate information indicating a flow rate of the etching liquid in each of the plurality of openings in the resist; a state acquisition unit that acquires liquid state information indicating a state of the etching liquid; an etching estimation unit that estimates the etching depth of each of the plurality of openings by using at least the liquid state information acquired by the state acquisition unit, the flow velocity information acquired by the flow velocity acquisition unit, and shape information indicating the shape of each of the plurality of openings; an evaluation unit that evaluates an etching result when an etching liquid corresponding to the liquid state information is used, based on the etching depth at each of the plurality of openings estimated by the etching estimation unit; an etching solution adjusting unit that determines an adjustment instruction for the etching solution based at least on the evaluation by the evaluating unit; An etching solution management system comprising:

2. The etching liquid management system according to claim 1 , wherein the liquid state information includes at least one of an ORP value, a temperature, and a concentration of the etching liquid.

3. The etching liquid management system according to claim 1 , wherein the shape information includes at least one of an opening width and a resist thickness of each of the plurality of openings.

4. The etching liquid management system according to claim 1 , wherein the flow velocity information is a flow velocity vector.

5. The etching liquid management system according to claim 1 , wherein the evaluation unit evaluates the etching result based on a feature amount relating to a distribution of the etching depth among the plurality of openings.

6. a first step of acquiring flow rate information indicating a flow rate of an etching solution in each of a plurality of openings in the resist; a second step of acquiring liquid state information indicating a state of the etching liquid; a third step of estimating an etching depth in each of the plurality of openings by using at least the liquid state information acquired in the second step, the flow velocity information acquired in the first step, and shape information indicating a shape of each of the plurality of openings; a fourth step of evaluating an etching result when an etching solution corresponding to the liquid state information is used, based on the etching depth at each of the plurality of openings estimated in the third step; a fifth step of determining adjustment instructions for the etching solution based at least on the evaluation from the fourth step; and The etching solution management method includes the steps of:

7. Computer, a flow rate acquiring unit that acquires flow rate information indicating the flow rate of the etching solution in each of the plurality of openings in the resist; a state acquisition unit that acquires liquid state information indicating the state of the etching liquid; an etching estimation unit that estimates the etching depth of each of the plurality of openings by using at least the liquid state information acquired by the state acquisition unit, the flow velocity information acquired by the flow velocity acquisition unit, and shape information indicating the shape of each of the plurality of openings; an evaluation unit that evaluates an etching result when an etching liquid corresponding to the liquid state information is used, based on the etching depth at each of the plurality of openings estimated by the etching estimation unit; an etching solution adjusting unit that determines an adjustment instruction for the etching solution based at least on the evaluation by the evaluating unit; A program to function as a

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