Ozone concentrator, substrate processing apparatus, and ozone supply method

Abstract

The invention provides an ozone concentrator, a substrate processing apparatus and an ozone supply method, which can execute stable flow control when ozone gas is supplied. An ozone concentrator according to one embodiment of the present disclosure is provided with: a pump provided in a supply flow path through which ozone gas flows; a flow rate controller provided in the supply flow path downstream of the pump; and a pressure controller that controls the pressure of the supply flow path between the pump and the flow controller to a set pressure.

Description

Technical Field

[0001] The present disclosure relates to an ozone concentrator, a substrate processing device, and an ozone supply method. Background Art

[0002] There is known an ozone gas concentrator that allows ozone gas generated by an ozone generator to be adsorbed on an adsorbent and, when desorbed, desorbs the ozone gas in a vacuum state by a vacuum pump attached to a gas outlet passage (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 5427412 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The present disclosure provides a technology capable of performing stable flow rate control when supplying ozone gas.

[0008] Solutions for solving problems

[0009] An ozone concentrator according to one embodiment of the present invention comprises: a pump disposed in a supply flow path for circulating ozone gas; a flow controller disposed in the supply flow path downstream of the pump; and a pressure controller that controls the pressure of the supply flow path between the pump and the flow controller to a set pressure.

[0010] Effects of the Invention

[0011] According to the present disclosure, it is possible to perform stable flow rate control when supplying ozone gas. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0013] Figure 2 It is a figure which shows the result of Example.

[0014] Figure 3 It is a figure which shows the result of a comparative example. DETAILED DESCRIPTION

[0015] Next, refer to the attached Figure 1 In all the drawings, the same or corresponding components or parts are denoted by the same or corresponding reference numerals, and repeated descriptions are omitted.

[0016] (Substrate processing equipment)

[0017] Reference Figure 1 A substrate processing apparatus 1 according to the embodiment will be described. Figure 1 It is a diagram showing a substrate processing apparatus 1 according to the embodiment.

[0018] The substrate processing apparatus 1 includes an ozone generator 10 , an ozone concentrator 30 , a processing unit 50 , and an apparatus controller 90 .

[0019] The ozone generator 10 generates ozone gas.

[0020] The ozone concentrator 30 has a supply flow path 31, an adsorption unit 32, a pump 33, a first filter 34, a buffer tank 35, a first pressure gauge 36, a flow controller 37, a second pressure gauge 38, a concentration meter 39, an on-off valve 40, a second filter 41, a vacuum exhaust flow path 42, an on-off valve 43, a pressure controller 44 and a control unit 45.

[0021] The supply flow path 31 connects the ozone generator 10 and the processing unit 50. The supply flow path 31 allows the ozone gas generated by the ozone generator 10 to flow and be supplied to the processing unit 50. In the supply flow path 31, an adsorption unit 32, a pump 33, a first filter 34, a buffer tank 35, a first pressure gauge 36, a flow controller 37, a second pressure gauge 38, a concentration meter 39, an on-off valve 40, and a second filter 41 are provided in order from the upstream.

[0022] The adsorption section 32 includes two adsorption columns 32a and 32b. The two adsorption columns 32a and 32b are connected in parallel with each other. In this case, by performing adsorption operation using the other adsorption column 32b (adsorption column 32a) during the separation operation using the adsorption column 32a (or adsorption column 32b) on one side, ozone gas can be continuously supplied to the downstream of the supply flow path 31. The adsorption section 32 may also include only one adsorption column, or may include three or more adsorption columns. An adsorbent for selectively adsorbing ozone gas is filled inside each adsorption column 32a and 32b. The adsorbent is, for example, silica gel. The adsorbent may also be zeolite.

[0023] The pump 33 delivers the ozone gas to the downstream of the supply flow path 31. The pump 33 decompresses and exhausts the ozone gas stored in the adsorption columns 32a and 32b and supplies it to the downstream.

[0024] The first filter 34 filters the ozone gas flowing through the supply flow path 31 to remove foreign matter contained in the ozone gas.

[0025] The buffer tank 35 temporarily stores ozone gas. When the concentration of ozone gas from the adsorption columns 32a and 32b changes, the buffer tank 35 averages the concentration. Thus, the ozone gas can be supplied to the downstream of the supply flow path 31 while maintaining the concentration of the ozone gas within a certain range.

[0026] The first pressure gauge 36 is provided in the supply flow path 31 between the buffer tank 35 and the flow controller 37. The first pressure gauge 36 detects the pressure of the ozone gas flowing through the supply flow path 31 between the buffer tank 35 and the flow controller 37. The first pressure gauge 36 detects the primary pressure of the flow controller 37.

[0027] The flow rate controller 37 controls the flow rate of the ozone gas flowing through the supply flow path 31. The flow rate controller 37 is, for example, a mass flow controller (MFC: Mass Flow Controller).

[0028] The second pressure gauge 38 is provided in the supply flow path 31 between the flow controller 37 and the concentration meter 39. The second pressure gauge 38 detects the pressure of the ozone gas flowing through the supply flow path 31 between the flow controller 37 and the concentration meter 39. The second pressure gauge 38 detects the secondary pressure of the flow controller 37.

[0029] The concentration meter 39 detects the concentration of the ozone gas flowing through the supply flow path 31 .

[0030] The on-off valve 40 is a valve that switches the flow of ozone gas on and off. The on-off valve 40 allows the ozone gas to flow to the second filter 41 downstream when it is open, and does not allow the ozone gas to flow to the second filter 41 downstream when it is closed.

[0031] The second filter 41 filters the ozone gas flowing through the supply flow path 31 to remove foreign matter contained in the ozone gas.

[0032] The vacuum exhaust flow path 42 branches off from the supply flow path 31 between the buffer tank 35 and the flow controller 37. The vacuum exhaust flow path 42 exhausts the ozone gas in the supply flow path 31. The vacuum exhaust flow path 42 is provided with an on-off valve 43 and a pressure controller 44 in order from the upstream.

[0033] The on-off valve 43 is a valve that switches the flow of ozone gas on and off. The on-off valve 43 allows the ozone gas to flow to the downstream pressure controller 44 when it is open, and does not allow the ozone gas to flow to the downstream pressure controller 44 when it is closed.

[0034] The pressure controller 44 has a built-in pressure gauge for detecting the primary pressure of the pressure controller 44. The pressure controller 44 is used to control the pressure detected by the built-in pressure gauge to a set pressure. As a result, the pressure of the vacuum exhaust flow path 42 upstream of the pressure controller 44 is adjusted to the set pressure. When the on-off valve 43 is in an open state, the vacuum exhaust flow path 42 upstream of the pressure controller 44 is connected to the supply flow path 31 between the buffer tank 35 and the flow controller 37. Therefore, when the on-off valve 43 is in an open state, the pressure of the supply flow path 31 between the buffer tank 35 and the flow controller 37 is adjusted to the set pressure. As a result, the primary pressure of the flow controller 37 is stabilized, so that stable flow control can be performed when supplying ozone gas to the processing unit 50. The pressure controller 44 is, for example, a pressure control valve (PCV: Pressure Control Valve).

[0035] The pressure controller 44 may also control the pressure detected by the first pressure gauge 36 to a set pressure. In this case, as described above, the pressure of the supply flow path 31 between the buffer tank 35 and the flow controller 37 is adjusted to the set pressure. As a result, the primary pressure of the flow controller 37 is stabilized, so that stable flow control can be performed when the ozone gas is supplied to the processing unit 50.

[0036] The set pressure is, for example, a predetermined fixed value. The fixed value may be, for example, a pressure equal to or higher than the total pressure of the secondary pressure of the flow controller 37 and the minimum required pressure difference of the flow controller 37 that may be taken when the flow controller 37 is changed from the minimum flow rate that can be controlled to the maximum flow rate. In this case, no matter which flow rate from the minimum flow rate to the maximum flow rate that can be controlled is changed to the set flow rate of the flow controller 37, stable flow control can be performed when the ozone gas is supplied to the processing unit 50. The secondary pressure of the flow controller 37 can be detected by the second pressure gauge 38.

[0037] The set pressure may also be a variable value determined according to the pressure detected by the second pressure gauge 38. The set pressure may be the total pressure of the pressure detected by the second pressure gauge 38 and the minimum required pressure difference of the flow controller 37. In this case, the secondary pressure of the pump 33 can be lowered. Therefore, the life of the pump 33 is improved.

[0038] The control unit 45 can control the set pressure of the pressure controller 44 to the total pressure of the pressure detected by the second pressure gauge 38 and the minimum required pressure difference of the flow controller 37. When the set flow rate of the flow controller 37 is large, the pressure detected by the second pressure gauge 38 becomes high, and when the set flow rate of the flow controller 37 is small, the pressure detected by the second pressure gauge 38 becomes low. In this way, the pressure detected by the second pressure gauge 38 changes according to the set flow rate of the flow controller 37. Therefore, by controlling the set pressure of the pressure controller 44 to the total pressure of the pressure detected by the second pressure gauge 38 and the minimum required pressure difference of the flow controller 37 by the control unit 45, the secondary pressure of the pump 33 can be reduced regardless of the set flow rate of the flow controller 37.

[0039] The processing unit 50 includes a processing container 51 , a holding unit 52 , an introduction channel 53 , an on-off valve 54 , a discharge channel 55 , and an on-off valve 56 .

[0040] The processing container 51 is a container having a processing space formed therein that can accommodate a substrate W. The substrate W is processed in the processing space. The substrate W is, for example, a semiconductor wafer.

[0041] The holding unit 52 is provided inside the processing container 51. The holding unit 52 holds, for example, one substrate W in a horizontal state. The holding unit 52 may be capable of holding two or more substrates W in a horizontal state.

[0042] The introduction flow path 53 connects the supply flow path 31 and the processing container 51. The introduction flow path 53 introduces the ozone gas from the supply flow path 31 into the processing container 51. The introduction flow path 53 is provided with an on-off valve 54.

[0043] The on-off valve 54 is a valve that switches the flow of ozone gas on and off. The on-off valve 54 allows the ozone gas to flow to the downstream processing container 51 when it is open, and does not allow the ozone gas to flow to the downstream processing container 51 when it is closed.

[0044] The exhaust flow path 55 is connected to the processing container 51. The exhaust flow path 55 exhausts the ozone gas in the processing container 51. The exhaust flow path 55 is provided with an on-off valve 56.

[0045] The on-off valve 56 is a valve that switches the flow of ozone gas on and off. The on-off valve 56 allows the ozone gas to flow to the downstream discharge flow path 55 when it is open, and does not allow the ozone gas to flow to the downstream discharge flow path 55 when it is closed.

[0046] The device controller 90 is, for example, a computer, and includes a computing unit 91 and a storage unit 92. The storage unit 92 stores programs for controlling various processes performed in the substrate processing device 1. The computing unit 91 controls the operation of the substrate processing device 1 by reading and executing the program stored in the storage unit 92. The program can be recorded in a storage medium that can be read by a computer, and installed from the storage medium to the storage unit 92 of the device controller 90. As a storage medium that can be read by a computer, there are, for example, a hard disk (HD), a floppy disk (FD), a compact disk (CD), a magneto-optical disk (MO), a memory card, etc. The device controller 90 can also replace the control unit 45 to control the set pressure of the pressure controller 44 to the total pressure of the pressure detected by the second pressure gauge 38 and the minimum required pressure difference of the flow controller 37.

[0047] (Ozone supply method)

[0048] An example of a method for the ozone concentrator 30 to supply ozone gas to the processing unit 50 is described. When the ozone concentrator 30 supplies ozone gas to the processing unit 50, the control unit 45 controls the on-off valve 43 to be in an open state, and the pressure controller 44 controls the pressure detected by the built-in pressure gauge or the pressure detected by the first pressure gauge 36 to be a set pressure. In this case, the pressure of the supply flow path 31 between the buffer tank 35 and the flow controller 37 is adjusted to the set pressure. Therefore, the primary pressure of the flow controller 37 is stable, so that stable flow control can be performed when the ozone gas is supplied to the processing unit 50.

[0049] When the ozone concentrator 30 supplies ozone gas to the processing unit 50, the control unit 45 may control the set pressure of the pressure controller 44 to the total pressure of the pressure detected by the second pressure gauge 38 and the minimum required pressure difference of the flow controller 37. In this case, the secondary pressure of the pump 33 can be reduced. Therefore, the life of the pump 33 is improved.

[0050] (Evaluation results)

[0051] In the substrate processing apparatus 1 according to the embodiment, the change in the primary pressure of the flow controller 37 and the change in the flow rate of the ozone gas when the ozone gas is supplied to the processing unit 50 while changing the set flow rate of the flow controller 37 (Example). In the Example, the pressure controller 44 controls the pressure detected by the first pressure gauge 36 to the set pressure while supplying the ozone gas to the processing unit 50. At this time, the control unit 45 controls the set pressure to the total pressure of the pressure detected by the second pressure gauge 38 and the minimum required pressure difference of the flow controller 37.

[0052] For comparison, in a substrate processing apparatus (not shown) in which the pressure controller 44 is removed from the substrate processing apparatus 1, changes in the primary pressure of the flow controller 37 and changes in the flow rate of the ozone gas when the ozone gas is supplied to the processing unit 50 while changing the set flow rate of the flow controller 37 (comparative example) are measured. In the comparative example, when the pressure detected by the first pressure gauge 36 exceeds the threshold pressure, the on-off valve 43 is changed from the closed state to the open state, so that the primary pressure of the flow controller 37 is controlled to be less than the threshold pressure while supplying ozone gas to the processing unit 50.

[0053] Figure 2 It is a figure which shows the result of Example. Figure 3 is a graph showing the results of the comparative example. Figure 2 and Figure 3 In FIG. 1 , the horizontal axis represents time [seconds], the vertical axis on the left represents the pressure detected by the first pressure gauge 36 (the primary pressure of the flow controller 37) [kPaA], and the vertical axis on the right represents the flow rate detected by the flow controller 37 [SLM]. Figure 3 In FIG, a dashed line is used to represent the threshold pressure.

[0054] like Figure 2 As shown in FIG. 1 , it can be seen that in the embodiment, even when the set flow rate of the flow controller 37 is changed, stable flow control without flow fluctuation is performed. This is considered to be because the primary pressure of the flow controller 37 is stabilized by the pressure control performed by the pressure controller 44. In contrast, Figure 3 As shown, it is known that in the comparative example, the flow rate fluctuation is large after changing the set flow rate of the flow controller 37. This is considered to be because the pressure fluctuation is large when the on-off valve 43 is opened and closed, and the primary pressure of the flow controller 37 fluctuates with the opening and closing of the on-off valve 43.

[0055] In addition, if Figure 2 As shown in FIG. 1 , it can be seen that in the embodiment, when the set flow rate of the flow controller 37 is changed within the range of 5SLM to 10SLM, the primary pressure of the flow controller 37 is 80kPaA to 120kPaA. Figure 3 As shown, it can be seen that in the comparative example, when the set flow rate of the flow controller 37 is changed within the range of 5SLM to 10SLM, the primary pressure of the flow controller 37 is 130kPaA to 150kPaA. This result shows that in the embodiment, the primary pressure of the flow controller 37, that is, the secondary pressure of the pump 33 can be lowered compared to the comparative example.

[0056] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive. The embodiments described above may be omitted, replaced, and modified in various ways without departing from the appended claims and the gist thereof.

[0057] Description of Reference Numerals

[0058] 30: ozone concentrator; 31: supply flow path; 33: pump; 37: flow controller; 44: pressure controller.

Claims

1. An ozone concentrator, comprising: a pump disposed in a supply flow path through which ozone gas flows; a flow controller disposed in the supply flow path downstream of the pump; and A pressure controller controls the pressure of the supply flow path between the pump and the flow controller to a set pressure.

2. The ozone concentrator according to claim 1, wherein: The pressure controller is provided in a vacuum exhaust flow path branched from the supply flow path between the pump and the flow controller.

3. The ozone concentrator according to claim 1 or 2, wherein: The set pressure is a predetermined fixed value.

4. The ozone concentrator according to claim 1 or 2, wherein: A pressure gauge is further provided, the pressure gauge being used to detect the pressure of the supply flow path downstream of the flow controller, The set pressure is a variable value determined according to the pressure detected by the pressure gauge.

5. The ozone concentrator according to claim 4, wherein: The device further includes a control unit configured to control the set pressure to be a total pressure of the pressure detected by the pressure gauge and a minimum required differential pressure of the flow controller.

6. A substrate processing device comprising: a processing unit that processes the substrate; and an ozone concentrator connected to the processing unit, in, The ozone concentrator has: a pump disposed in a supply flow path through which ozone gas flows; a flow controller disposed in the supply flow path downstream of the pump; and A pressure controller controls the pressure of the supply flow path between the pump and the flow controller to a set pressure.

7. An ozone supply method, using an ozone concentrator to supply ozone gas, the ozone concentrator having: a pump disposed in a supply flow path through which ozone gas flows; a flow controller disposed in the supply flow path downstream of the pump; a pressure controller that controls the pressure of the supply flow path between the pump and the flow controller to a set pressure; and a pressure gauge for detecting the pressure of the supply flow path downstream of the flow controller, The ozone supply method comprises: The set pressure is controlled to be a total pressure of the pressure detected by the pressure gauge and a minimum required pressure difference of the flow controller.

Images