Treatment apparatus and gas supply method

Abstract

To provide a technique that can precisely control the amount of gas supply into a processing container.SOLUTION: A processing apparatus includes: a processing container configured to accommodate a substrate; a storage tank connected to the processing container via a gas supply pipe; a pressure sensor configured to detect a pressure in the storage tank; a valve provided in the gas supply pipe between the processing container and the storage tank; and a controller configured to control an opening degree of the valve based on the pressure detected by the pressure sensor.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a processing apparatus and a gas supply method. [Background technology]

[0002] There is known a technique for inputting a detection value of a pressure sensor on the secondary side of a processing vessel into a controller and controlling the amount of gas supplied into the processing vessel so that the pressure inside the processing vessel is constant (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-179397 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for accurately controlling the amount of gas supplied into a processing chamber. [Means for solving the problem]

[0005] A processing apparatus according to one aspect of the present disclosure includes a processing vessel for accommodating a substrate, a storage tank connected to the processing vessel via a gas supply pipe for storing a gas, a pressure sensor for detecting a pressure in the storage tank, a valve provided on the gas supply pipe between the processing vessel and the storage tank, and a controller, wherein the controller is configured to calculate an amount of pressure drop in the storage tank by subtracting a detection value of the pressure sensor when the valve is open from a detection value of the pressure sensor before the valve is opened when the gas stored in the storage tank is supplied into the processing vessel, and to control an opening degree of the valve so that the calculated amount of pressure drop becomes equal to a set discharge pressure within a predetermined time. The controller is configured to perform ALD film formation by intermittently supplying a gas from the storage tank into the processing vessel to deposit a film, and to control an opening degree of the valve based on the pressure detected by the pressure sensor when the gas is supplied into the processing vessel. . Effect of the Invention

[0006] According to the present disclosure, the amount of gas supplied into a processing chamber can be controlled with precision. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a block diagram illustrating an example of a processing device according to an embodiment. [Diagram 2] FIG. 1 is a diagram showing an example of a gas supply method according to an embodiment; [Diagram 3] Figure showing the results of measuring the change in tank internal pressure over time [Figure 4] FIG. 13 is a diagram showing the calculation result of the error between the set discharge amount and the actual discharge amount. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In all of the accompanying drawings, the same or corresponding members or parts are designated by the same or corresponding reference numerals, and duplicated descriptions will be omitted.

[0009] [Processing Device] An example of a processing device according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing an example of a processing device according to an embodiment.

[0010] The processing apparatus 1 includes a processing vessel 10, a gas supply unit 20, an exhaust unit 30, a discharge amount control unit 40, and the like.

[0011] The processing vessel 10 is a vertical vessel that houses a boat holding substrates in multiple stages in a vertical direction in a horizontal position, and performs substrate processing. However, the processing vessel 10 may be a vessel that houses a mounting stage on which one or more substrates are placed, and performs substrate processing. The substrate is, for example, a semiconductor wafer. The substrate processing includes various processes in which a processing gas is supplied into the processing vessel 10 to process the substrate, such as a film formation process and an etching process. The film formation process includes atomic layer deposition (ALD), chemical vapor deposition (CVD), and the like.

[0012] The gas supply unit 20 includes a gas supply pipe 21, a gas source 22, a mass flow controller 23, a storage tank 24, a furnace port valve 25, and the like.

[0013] The gas supply pipe 21 is a pipe for supplying a processing gas from a gas source 22 into the processing vessel 10, and is connected to, for example, an injector (not shown) that introduces the processing gas into the processing vessel 10. A mass flow controller 23, a storage tank 24, and a furnace port valve 25 are installed in this order in the gas supply pipe 21 from the gas source 22 side.

[0014] The gas source 22 is a supply source that supplies a process gas into the storage tank 24 and the process vessel 10. The gas source 22 may be, for example, a tank filled with a process gas, or a connection port through which the process gas is supplied. The process gas includes, for example, a source gas used in a film formation process and an etching gas used in an etching process.

[0015] The mass flow controller 23 measures the mass flow rate of the process gas stored in the storage tank 24 from the gas source 22, and controls the flow rate.

[0016] The storage tank 24 is a tank for storing the processing gas, and is provided in order to supply a large amount of processing gas into the processing vessel 10 in a short time. The storage tank 24 temporarily stores a large amount of processing gas and supplies it all at once into the processing vessel 10 in a short time, thereby enabling the supply of a large amount of processing gas in a short time. The storage tank 24 is also called a buffer tank.

[0017] The opening degree of the furnace opening valve 25 is controlled by an electropneumatic regulator 44, which will be described later. By controlling the opening degree of the furnace opening valve 25, the discharge amount of the processing gas supplied from the storage tank 24 into the processing vessel 10 is controlled.

[0018] The exhaust section 30 includes an exhaust pipe 31, an exhaust valve 32, an exhaust device 33, and the like.

[0019] The exhaust pipe 31 is a pipe for exhausting the processing gas inside the processing vessel 10, and is connected, for example, to an exhaust port (not shown) of the processing vessel 10. An exhaust valve 32 and an exhaust device 33 are provided in this order in the exhaust pipe 31 from the processing vessel 10 side.

[0020] The exhaust valve 32 is a valve for adjusting the exhaust amount of the process gas flowing through the exhaust pipe 31. The exhaust valve 32 may be, for example, an APC (Automatic Pressure Controller) valve.

[0021] The exhaust device 33 evacuates the inside of the processing chamber 10 via the exhaust pipe 31. The exhaust device 33 includes a vacuum pump such as a dry pump or a turbo molecular pump.

[0022] The discharge amount control unit 40 controls the discharge amount of the processing gas supplied from the storage tank 24 into the processing vessel 10. The discharge amount control unit 40 includes a pressure sensor 41, a controller 42, an input device 43, an electropneumatic regulator 44, and the like.

[0023] The pressure sensor 41 is provided in the storage tank 24. The pressure sensor 41 detects the pressure inside the storage tank 24 (hereinafter also referred to as the “tank internal pressure”), and outputs the detected value to the controller 42.

[0024] The controller 42 is configured to perform arithmetic processing including control. The controller 42 may be, for example, a computer. The controller 42 is configured to control the opening degree of the furnace port valve 25 via the electropneumatic regulator 44 based on the detection value of the pressure sensor 41. However, the controller 42 may be configured to control the opening degree of the furnace port valve 25 without using the electropneumatic regulator 44.

[0025] The input device 43 is a device for an operator or the like to input various information. The various information includes, for example, the discharge amount of the processing gas to be supplied from the storage tank 24 into the processing vessel 10. The discharge amount of the processing gas is specified, for example, by a pressure value. Hereinafter, the specified pressure value is referred to as a set discharge pressure. The input device 43 may be included in, for example, an equipment controller that controls the entire processing apparatus 1, or may be a computer provided separately from the equipment controller.

[0026] The electro-pneumatic regulator 44 controls the opening of the furnace port valve 25 by air pressure based on a command (electrical signal) from the controller 42.

[0027] [Gas supply method] 2, a case will be described in which, as an example of the gas supply method of the embodiment, a film is formed by ALD in the processing apparatus 1, in which a processing gas is intermittently supplied into the processing vessel 10 to deposit a film. Fig. 2 is a diagram showing an example of the gas supply method of the embodiment, and shows the change in tank internal pressure over time when a processing gas is intermittently supplied from a storage tank 24 into the processing vessel 10. In Fig. 2, the horizontal axis indicates time, and the vertical axis indicates the tank internal pressure [Torr].

[0028] In the following description, it is assumed that, at the start of the gas supply method, a substrate is accommodated in the processing vessel 10 and processing gas is stored in the storage tank 24 so that the tank internal pressure is 290 Torr. It is also assumed that, prior to the start of the gas supply method, an operator or the like has input a set discharge pressure of 280 Torr via the input device 43.

[0029] First, the controller 42 sends a command to the electro-pneumatic regulator 44 to open the furnace port valve 25. Based on the command, the electro-pneumatic regulator 44 opens the furnace port valve 25. This starts the first supply of the processing gas from the storage tank 24 into the processing vessel 10, and the tank internal pressure starts to decrease from 290 Torr.

[0030] When the first supply of the processing gas is started, the controller 42 controls the furnace port valve 25 in a variable opening mode. The variable opening mode is a mode in which the opening of the furnace port valve 25 is controlled so that the amount of drop in the tank internal pressure becomes equal to the set discharge pressure within a predetermined time. The amount of drop in the tank internal pressure is calculated by subtracting the detection value of the pressure sensor 41 when the furnace port valve 25 is open from the detection value of the pressure sensor 41 before the furnace port valve 25 is opened. In the example of FIG. 2, the controller 42 controls the opening of the furnace port valve 25 so that the amount of drop in the tank internal pressure becomes equal to the set discharge pressure of 280 Torr within a predetermined time t1, that is, so that the tank internal pressure becomes 10 Torr (290 Torr-280 Torr).

[0031] After a predetermined time has elapsed, the controller 42 sends a command to the electropneumatic regulator 44 to close the furnace port valve 25. The electropneumatic regulator 44 closes the furnace port valve 25 based on the command. This stops the first supply of the processing gas from the storage tank 24 to the processing vessel 10. The controller 42 also controls an open / close valve (not shown) and the mass flow controller 23, which are interposed between the gas source 22 and the storage tank 24, to supply the processing gas from the gas source 22 to the storage tank 24 and store it therein. In the example of FIG. 2, the processing gas is stored in the storage tank 24 until the tank internal pressure reaches 300 Torr.

[0032] Next, the controller 42 sends a command to the electro-pneumatic regulator 44 to open the furnace port valve 25. Based on the command, the electro-pneumatic regulator 44 opens the furnace port valve 25. This starts a second supply of the processing gas from the storage tank 24 into the processing vessel 10, and the tank internal pressure starts to decrease from 300 Torr.

[0033] When the second supply of the process gas is started, the controller 42 controls the furnace port valve 25 in the variable opening mode. In the example of Fig. 2, the controller 42 controls the opening of the furnace port valve 25 so that the amount of drop in the tank internal pressure within a predetermined time t1 becomes equal to the set discharge pressure of 280 Torr, that is, so that the tank internal pressure becomes 20 Torr (300 Torr - 280 Torr).

[0034] After a predetermined time has elapsed, the controller 42 sends a command to the electropneumatic regulator 44 to close the furnace port valve 25. The electropneumatic regulator 44 closes the furnace port valve 25 based on the command. This stops the second supply of the processing gas from the storage tank 24 to the processing vessel 10. The controller 42 also controls an open / close valve (not shown) and a mass flow controller 23, etc., that are interposed between the gas source 22 and the storage tank 24, to supply the processing gas from the gas source 22 to the storage tank 24 and store it therein. In the example of FIG. 2, the processing gas is stored in the storage tank 24 until the tank internal pressure reaches 305 Torr.

[0035] Thereafter, the controller 42 performs the third and subsequent supply of the processing gas in the same manner as the first and second supply of the processing gas. In the third supply of the processing gas, the controller 42 controls the aperture of the furnace port valve 25 so that the tank internal pressure drops to the set discharge pressure of 280 Torr within a predetermined time, i.e., the tank internal pressure is 25 Torr (305 Torr-280 Torr). In the fourth supply of the processing gas, the controller 42 controls the aperture of the furnace port valve 25 so that the tank internal pressure drops to the set discharge pressure of 280 Torr within a predetermined time, i.e., the tank internal pressure is 20 Torr (300 Torr-280 Torr).

[0036] The process gas is supplied a set number of times, which is determined by a recipe or the like, to deposit a film having a desired thickness on the substrate.

[0037] Incidentally, in the film formation by ALD in the processing apparatus 1, the film thickness uniformity may vary between apparatuses due to variations and changes over time in hardware such as the storage tank 24, the furnace port valve 25, the exhaust valve 32, the exhaust device 33, the injector, etc. This is believed to be because the supply amount of the processing gas from the storage tank 24 to the processing vessel 10 is not stable due to the variations and changes over time in the hardware.

[0038] One method for stabilizing the supply of processing gas into the processing vessel is to use a furnace port valve with a strictly controlled CV value, but this method has limitations on product yield.

[0039] Another example of a method for stabilizing the amount of processing gas supplied into the processing vessel is to input the detection value of a pressure sensor provided on the secondary side of the processing vessel into a controller, and control the amount of processing gas supplied so that the detection value is the same every time. However, in this method, since the processing vessel is between the storage tank and the pressure sensor, there is a time lag between when the processing gas is supplied from the storage tank into the processing vessel and when this is reflected in the detection value of the pressure sensor, making it difficult to achieve quick and precise control.

[0040] In contrast, according to the gas supply method of the embodiment, the controller 42 controls the aperture of the furnace port valve 25 based on the detection value of the pressure sensor 41 monitoring the pressure in the storage tank 24. That is, the controller 42 directly controls the supply amount of the processing gas supplied from the storage tank 24 into the processing vessel 10. This allows the supply amount of the processing gas into the processing vessel 10 to be promptly and precisely controlled. As a result, the pressure in the processing vessel 10 can also be precisely controlled.

[0041] Furthermore, according to the gas supply method of the embodiment, when the furnace port valve 25 is opened, the controller 42 controls the aperture of the furnace port valve 25 so that the amount of drop in the tank internal pressure within a predetermined time becomes equal to the set discharge pressure. This allows the process gas at the set discharge pressure to be supplied from the storage tank 24 into the process vessel 10 within a predetermined time, so that the same amount of process gas can be supplied into the process vessel 10 every time during film formation by ALD. As a result, film thickness uniformity is improved.

[0042] In the above embodiment, the controller 42 controls the throat valve 25 in the variable opening mode immediately after the throat valve 25 is opened. However, the present disclosure is not limited to this. For example, the controller 42 may control the throat valve 25 in the fixed opening mode until a predetermined time has elapsed since the throat valve 25 was opened, and then control the throat valve 25 in the variable opening mode. The fixed opening mode is a mode in which the throat valve 25 is fixed to a constant opening. For example, by setting the opening of the throat valve 25 in the fixed opening mode to be large, a large amount of processing gas can be supplied from the storage tank 24 to the processing vessel 10 in a short time immediately after the throat valve 25 is opened, and the supply amount of processing gas can be accurately adjusted for the remaining time.

[0043] [Example] An example in which the gas supply method of the embodiment was carried out will be described with reference to Fig. 3 and Fig. 4. In the example, the furnace port valve 25 was controlled in the fixed opening mode until a predetermined time (0.5 seconds) had elapsed since the furnace port valve 25 was opened, and the furnace port valve 25 was controlled in the variable opening mode after the predetermined time had elapsed. The total time during which the furnace port valve 25 was controlled in the fixed opening mode and the time during which the furnace port valve 25 was controlled in the variable opening mode was set to 3 seconds. In addition, five conditions A to E were carried out, which had different combinations of the tank internal pressure before the furnace port valve 25 was opened (hereinafter referred to as "tank internal pressure during storage") and the set discharge pressure. In the example, evaluation was carried out using nitrogen gas instead of the processing gas.

[0044] Condition A is a condition in which the tank internal pressure during storage is set to 380 Torr, the set discharge pressure is set to 300 Torr, and the target tank internal pressure is 80 Torr (380 Torr-300 Torr).

[0045] Condition B is a condition in which the tank internal pressure during storage is set to 360 Torr, the set discharge pressure is set to 300 Torr, and the target tank internal pressure is 60 Torr (360 Torr-300 Torr).

[0046] Condition C is a condition in which the tank internal pressure during storage is set to 310 Torr, the set discharge pressure is set to 290 Torr, and the target tank internal pressure is 20 Torr (310 Torr-290 Torr).

[0047] Condition D is a condition in which the tank internal pressure during storage is set to 340 Torr, the set discharge pressure is set to 310 Torr, and the target tank internal pressure is 30 Torr (340 Torr-310 Torr).

[0048] Condition E is a condition in which the tank internal pressure during storage is set to 300 Torr, the set discharge pressure is set to 280 Torr, and the target tank internal pressure is 20 Torr (300 Torr-280 Torr).

[0049] Fig. 3 is a diagram showing the results of measuring the change in tank internal pressure over time. In Fig. 3, the horizontal axis represents time [seconds], and the vertical axis represents tank internal pressure [Torr]. In Fig. 3, the solid line, dotted line, dashed line, one-dot chain line, and two-dot chain line represent the results for condition A, condition B, condition C, condition D, and condition E, respectively.

[0050] 3, it can be seen that under all conditions A to E, the tank internal pressure significantly drops immediately after the furnace port valve 25 is opened, and then the tank internal pressure stabilizes at the target tank internal pressure. This result shows that a large amount of processing gas can be supplied from the storage tank 24 to the processing vessel 10 in a short time immediately after the furnace port valve 25 is opened, and the supply amount of processing gas can be accurately adjusted during the remaining time.

[0051] Fig. 4 is a diagram showing the calculation results of the error between the set discharge amount and the actual discharge amount. In Fig. 4, from the left column, the conditions, tank internal pressure during storage [Torr], target tank internal pressure [Torr], set discharge amount (set discharge pressure) [Torr], actual discharge amount (actual discharge pressure) [Torr], and error (actual discharge amount - set discharge amount) [Torr] are shown.

[0052] 4, it can be seen that the error of the actual discharge amount with respect to the set discharge amount is less than 2 Torr under all of the conditions A to E. This result shows that under all of the conditions A to E, the supply amount of the processing gas from the storage tank 24 to the processing vessel 10 can be accurately adjusted.

[0053] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0054] 1 Processing equipment 10 Processing vessel 21 Gas supply pipe 24 Storage Tank 25 Furnace mouth valve 41 Pressure Sensor 42 Controller

Claims

1. a processing vessel for accommodating a substrate; a storage tank connected to the processing vessel via a gas supply pipe and configured to store a gas; a pressure sensor for detecting a pressure in the storage tank; a valve provided in the gas supply pipe between the processing vessel and the storage tank; A controller; having the controller is configured to calculate a pressure drop amount in the storage tank by subtracting a detection value of the pressure sensor in an open state of the valve from a detection value of the pressure sensor before the valve is opened when the gas stored in the storage tank is supplied into the processing vessel, and to control an opening degree of the valve so that the calculated pressure drop amount becomes equal to a set discharge pressure within a predetermined time; the controller is configured to perform film formation by ALD, in which a gas is intermittently supplied from the storage tank into the processing vessel to deposit a film, and to control an opening degree of the valve based on the pressure detected by the pressure sensor when the gas is supplied into the processing vessel. Processing unit.

2. An input device for inputting the set discharge pressure is provided. The processing device of claim 1 .

3. the controller controls the opening degree of the valve in a mode in which the valve is fixed at a constant opening degree, and then controls the opening degree of the valve in a mode in which the opening degree of the valve is controlled so that an amount of pressure drop in the storage tank becomes equal to the set discharge pressure. The processing device according to claim 1 or 2.

4. The gas is a raw material gas. The processing device according to any one of claims 1 to 3.

5. storing the gas in a storage tank connected to the processing vessel via a gas supply pipe; supplying the gas stored in the storage tank into the processing vessel; having a valve is provided in the gas supply pipe between the processing vessel and the storage tank; In the supplying step, a pressure drop amount in the storage tank is calculated by subtracting the pressure in the storage tank when the valve is open from the pressure in the storage tank before the valve is opened, and an opening degree of the valve is controlled so that the calculated pressure drop amount becomes equal to a set discharge pressure within a predetermined time. In the supplying step, a film is formed by ALD in which a gas is intermittently supplied from the storage tank into the processing vessel to deposit a film, and an opening degree of the valve is controlled based on a pressure in the storage tank when the gas is supplied into the processing vessel. Gas supply method.

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