JP2022098959A - Substrate treatment method and substrate treatment device - Google Patents

Abstract

To provide a substrate treatment method capable of appropriately determining whether substrate cooling is normally being performed.SOLUTION: A substrate treatment method disclosed uses a substrate treatment device 100. The device 100 includes a cooling gas supply unit 150 (including a valve 154) for supplying a cooling gas to a space S between a stage 130 and a substrate 10. The method includes steps of: obtaining an opening of the valve 154 in a predetermined state; calculating a value indicating a change in the opening with respect to a reference value by comparing the opening with the reference value; and changing a first threshold of the opening, which is preset to determine whether substrate cooling is normally being performed during treatment of the substrate 10, to a second threshold based on the value indicating the change, and the method also includes a substrate treatment step of treating the substrate 10 while cooling the substrate 10. In the substrate treatment process, whether cooling of the substrate 10 is normally being performed is determined based on the opening of the valve 154 and the second threshold.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a substrate processing method and a substrate processing apparatus.

As one of the methods for processing a substrate, a method for processing the substrate with plasma is known. When processing a substrate with plasma, the substrate may be heated and malfunction may occur. Therefore, a method for performing plasma treatment while cooling the substrate has been conventionally proposed.

For example, Patent Document 1 (Japanese Unexamined Patent Publication No. 2002-184850) states that "in a process apparatus having a lower electrode on which a wafer is placed in a vacuum chamber and treating the surface of the wafer, the lower electrode and the wafer are used. A gas is filled between them, the pressure of the gas on the back surface of the wafer is indirectly obtained, and the filling pressure of the gas is adjusted so that the pressure on the back surface of the wafer becomes a predetermined pressure. A method for controlling a wafer temperature in a process apparatus, which is characterized in that the wafer temperature is maintained at a predetermined temperature by controlling the heat conduction between the two. "

Japanese Unexamined Patent Publication No. 2002-184850

In the method disclosed in Patent Document 1, the filling pressure of the gas is adjusted so that the pressure on the back surface of the wafer becomes a predetermined pressure. However, it may be difficult to properly cool the substrate by the conventional method. In such a situation, one of the purposes of the present disclosure is to provide a new substrate processing method and substrate processing apparatus capable of appropriately determining whether or not the substrate is normally cooled.

One aspect of the present disclosure relates to a substrate processing method using a substrate processing apparatus. The substrate processing apparatus includes a substrate processing chamber, a stage on which a substrate is placed and arranged in the substrate processing chamber, fixing means for fixing the substrate to the stage, and the stage and the substrate. The cooling gas supply unit includes a cooling gas supply unit for supplying cooling gas to the space between them and a depressurizing device for depressurizing the substrate processing chamber, and the cooling gas supply unit is a gas flow path connected to the space. A flow controller that controls the flow rate of the cooling gas supplied to the gas flow path, a pressure gauge that measures the pressure of the cooling gas in the gas flow path, and the pressure of the cooling gas in the gas flow path. Includes a valve that adjusts according to the opening degree and an exhaust device arranged on the downstream side of the valve. The substrate processing method includes an acquisition step of acquiring the opening degree of the valve when the pressure becomes a predetermined pressure while the substrate is fixed to the stage and the flow rate is set to a predetermined flow rate. The calculation step of calculating the value indicating the change of the opening degree with respect to the reference value by comparing the opening degree acquired in the acquisition step with the reference value, and the cooling of the substrate during the processing of the substrate. A threshold change step of changing the first threshold value of the opening degree of the valve, which is preset for determining whether or not the valve is normally performed, to a second threshold value based on the value indicating the change. A substrate processing step of processing the substrate while cooling the substrate with the cooling gas supplied by the cooling gas supply unit is included, and whether the substrate is normally cooled in the substrate processing step. Whether or not it is determined based on the opening degree of the valve and the second threshold value.

Another aspect of the present disclosure relates to a substrate processing apparatus for processing a substrate. The substrate processing apparatus includes a substrate processing chamber, a stage on which the substrate is placed and arranged in the substrate processing chamber, fixing means for fixing the substrate to the stage, and the stage and the substrate. Includes a cooling gas supply unit for supplying cooling gas to the space between the two, a depressurizing device for depressurizing the substrate processing chamber, and a control unit for controlling the fixing means and the cooling gas supply unit. The cooling gas supply unit controls the gas flow path connected to the space, the flow controller that controls the flow rate of the cooling gas supplied to the gas flow path, and the pressure of the cooling gas in the gas flow path. The control unit includes a pressure gauge for measuring, a valve for adjusting the pressure of the cooling gas in the gas flow path according to an opening degree, and an exhaust device arranged on the downstream side of the valve. The acquisition step of acquiring the opening degree of the valve when the pressure becomes a predetermined pressure while being fixed to the stage and setting the flow rate to a predetermined flow rate, and the acquisition step acquired in the acquisition step. A calculation step of calculating a value indicating a change in the opening degree with respect to the reference value by comparing the opening degree with the reference value, and whether or not the substrate is normally cooled during the processing of the substrate. It is supplied by the cooling gas supply unit and the threshold change step of changing the first threshold of the opening degree of the valve preset for determination to the second threshold value based on the value indicating the change. The substrate processing step of processing the substrate while cooling the substrate with the cooling gas is executed, and the control unit determines whether or not the substrate is normally cooled in the substrate processing step. , The determination is made based on the opening degree of the valve and the second threshold value.

According to the substrate processing method and the substrate processing apparatus according to the present disclosure, it is possible to appropriately determine whether or not the substrate is normally cooled.

It is a figure which shows typically the structure of the example of the substrate processing apparatus which concerns on this disclosure. It is a top view schematically showing an example of the substrate stage used in the substrate processing apparatus which concerns on this disclosure. It is a figure which shows typically the structure of a part of another example of the substrate processing apparatus which concerns on this disclosure. It is a figure which shows typically the flowchart of a part of an example of the substrate processing method which concerns on this disclosure.

Hereinafter, embodiments of the present disclosure will be described with reference to examples, but the present disclosure is not limited to the examples described below. In the following description, specific numerical values and materials may be exemplified, but other numerical values and materials may be applied as long as the effects of the present disclosure can be obtained. In this specification, when the term "numerical value A to numerical value B" is used, the range includes the numerical value A and the numerical value B.

In this specification, when a fluid (for example, cooling gas) flows in the order of points A, B, and C, the side of the point A may be referred to as the upstream side of the point B. Further, the side of the point C may be referred to as the downstream side of the point B.

(Board processing method)
The substrate processing method according to the present disclosure is a method using a substrate processing apparatus. Hereinafter, the substrate processing method may be referred to as a "board processing method (M)" or a "method (M)". The substrate processing apparatus is cooled in the space between the substrate processing chamber, the stage on which the substrate is placed, which is arranged in the substrate processing chamber, the fixing means for fixing the substrate to the stage, and the space between the stage and the substrate. It includes a cooling gas supply unit for supplying gas and a decompression device for depressurizing the substrate processing chamber. The cooling gas supply unit includes a gas flow path connected to the above space, a flow controller that controls the flow rate of the cooling gas supplied to the gas flow path, and a pressure gauge that measures the pressure of the cooling gas in the gas flow path. It includes a valve that adjusts the pressure of the cooling gas in the gas flow path according to the opening degree, and an exhaust device arranged on the downstream side of the valve. Hereinafter, the pressure of the cooling gas in the gas flow path may be referred to as “pressure (P)”.

The substrate processing method (M) includes an acquisition step (i), a calculation step (ii), a threshold value changing step (iii), and a substrate processing step (iv) in this order. The acquisition step (i) is a step of acquiring the opening degree of the valve when the pressure (P) becomes a predetermined pressure while the substrate is fixed to the stage and the flow rate is set to a predetermined flow rate. The calculation step (ii) is a step of calculating a value indicating a change in the opening degree with respect to the reference value by comparing the opening degree acquired in the acquisition step (i) with the reference value. The value indicating the change may be referred to as "change amount" below. In the threshold value changing step (iii), the first threshold value of the valve opening degree set in advance for determining whether or not the substrate is normally cooled during the processing of the substrate is set to the above-mentioned change amount. It is a step of changing to the second threshold value based on. The substrate processing step (iv) is a step of processing the substrate while cooling the substrate with the cooling gas supplied by the cooling gas supply unit. In the method (M), whether or not the substrate is normally cooled in the substrate processing step (iv) is the opening of the valve (the opening of the valve at the time of determination, that is, the opening of the valve in the step (iv). Degree) and a second threshold.

The opening degree of the valve is an index showing how much gas the valve allows to permeate, and is expressed as a percentage (%), for example. The opening degree of the valve can be acquired (measured) by using, for example, a commercially available valve (valve device) capable of outputting the value of the opening degree (or the value corresponding to the opening degree). As the acquisition value of the valve opening degree, a value output from the valve (valve device) may be used as the valve opening degree.

The stage is configured so that a space (cooling space) for holding the cooling gas is formed between the substrate and the stage. For example, the stage may have an annular protrusion to support the substrate. Alternatively, the stage may have a groove on its surface to which the cooling gas is supplied. When the substrate is fixed to the stage by the fixing means, the stage and the fixing means are configured so as to maintain a certain degree of airtightness.

A gas flow path (for example, a gas pipe) is connected to the cooling space. The cooling gas is supplied from a gas supply source (for example, a gas cylinder) to the cooling space through the gas flow path. At this time, the flow rate controller controls the flow rate of the supplied cooling gas. The gas flow path is connected to the exhaust device, and the pressure (P) in the gas flow path is adjusted by the exhaust device and the valve. A pressure gauge for measuring the pressure (P) of the cooling gas is arranged, for example, in the cooling space, the flow rate controller, and the gas flow path between the exhaust device.

The cooling gas conducts heat between the substrate stage and the substrate. As a result, the substrate is efficiently cooled. The type of cooling gas is not particularly limited, and any gas can be used. From the viewpoint of cooling efficiency, it is preferable to use a gas composed of atoms having a small atomic number or a gas having a small molecular weight as the cooling gas. Examples of cooling gases include helium gas.

The substrate processing chamber during substrate processing is usually maintained at a pressure lower than the cooling space. Therefore, if the substrate is not properly fixed, the cooling gas leaks from between the stage and the substrate into the substrate processing chamber. If the leakage of the cooling gas becomes excessive, the substrate processing will not be performed properly, so that a defective substrate may be manufactured. Alternatively, the pressure (P) may become an inappropriate value for other reasons, and cooling may not be performed properly. Therefore, it is necessary to determine at an early stage whether or not cooling by the cooling gas is properly performed (for example, whether or not the leakage of the cooling gas is excessive). For that purpose, it is preferable to set a predetermined threshold value for the opening degree of the valve and determine that the substrate is not normally cooled when the opening degree of the valve deviates from the predetermined threshold value.

When the substrate is processed for a long period of time, the cooling gas is supplied to the gas flow path at a set flow rate to reach a predetermined pressure (P) due to changes in the state of the device (for example, changes in the state of the exhaust system in the decompression device). The opening of the valve at that time may be changing. When the relationship between the valve opening degree and the pressure (P) changes, the threshold value (threshold value of the valve opening degree) set for detecting the cooling error of the substrate may deviate from an appropriate threshold value. By changing (calibrating) the threshold value based on the amount of change in the opening degree with respect to the reference value, error determination based on an appropriate threshold value becomes possible.

The substrate processing may be plasma processing as described later. Other examples of substrate processing include substrate processing that processes the substrate in a depressurized state, including, for example, vapor deposition and sputtering.

The substrate to be processed is not particularly limited. Examples of the substrate include a semiconductor substrate, a glass substrate, a resin substrate, a ceramics substrate and the like. Examples of semiconductor substrates include silicon substrates, III-V compound semiconductor substrates, and substrates made of other semiconductors. In addition, these substrates may be composed of a plurality of materials. For example, the semiconductor substrate may include an insulating portion and a metal portion. The semiconductor substrate may have an element region including an insulating portion and a metal portion.

The configuration of the substrate processing apparatus may be selected according to the substrate processing to be performed. For example, the configuration used for a vacuum device such as a plasma processing device may be applied to the configuration of the substrate processing device, if necessary. Examples of fixing means for fixing the substrate to the stage include an electrostatic chuck, a mechanical fixative (eg, a mechanical clamp) and the like. The decompression device is a device that decompresses the substrate processing chamber to a pressure lower than the atmospheric pressure. The depressurizing device may include, for example, a vacuum pump and may include a pressure adjusting valve for adjusting the pressure in the substrate processing chamber.

The substrate processing apparatus may include a cooling layer. The cooling layer is arranged on the substrate stage. An example of the cooling layer is made of a material having high thermal conductivity (for example, a metal material) and has a refrigerant flow path inside. In this case, the substrate processing device further includes a refrigerant circulation device that cools and circulates the refrigerant, and a refrigerant. The cooling layer can be cooled by circulating the cooled refrigerant in the refrigerant flow path by the refrigerant circulation device. The substrate stage can be cooled by cooling the cooling layer. By cooling the board stage, the board can be cooled efficiently. By using the cooling layer, the substrate can be cooled more efficiently. The refrigerant is not particularly limited, and a known refrigerant (for example, pure water or a fluorine solution) may be used. The cooling layer may be arranged adjacent to the substrate stage instead of being arranged on the substrate stage.

The substrate processing apparatus further includes equipment required for substrate processing, depending on the type of substrate processing. For example, when the substrate processing is plasma processing, the substrate processing apparatus includes equipment necessary for plasma processing. For example, the substrate processing apparatus includes a gas supply unit for supplying a gas for plasma processing into the substrate processing chamber. Further, the substrate processing apparatus includes an electrode for generating plasma and a power source for applying high frequency power to the electrode. The substrate processing apparatus may include an electrode for applying a bias voltage and a power source for applying electric power to the electrode.

In the acquisition step (i), the opening degree of the valve is acquired when the pressure (P) becomes a predetermined pressure while the substrate is fixed to the stage and the flow rate of the cooling gas is set to a predetermined flow rate. As a result, data on the relationship between the pressure (P) and the opening degree of the valve in the state of the device at that time is acquired. The above-mentioned predetermined flow rate and predetermined pressure may be preset by the user, for example. In order to make a proper comparison, the conditions related to the pressure (P) in the acquisition step (i) (predetermined flow rate of cooling gas, predetermined pressure of pressure (P), and exhaust conditions of the exhaust device) are acquired in the past. The conditions are the same as in step (i). That is, in the acquisition step (i), the exhaust device is also operated under predetermined operating conditions. However, even if the operating conditions are the same, the exhaust capacity of the exhaust device may change due to clogging of the exhaust system, which may affect the amount of change in the opening degree.

In the calculation step (ii), the amount of change in the opening degree with respect to the reference value is calculated by comparing the opening degree acquired in the acquisition step (i) with the reference value. The reference value (reference value for valve opening) is set in advance. The reference value may be set by the user, or the opening degree of the valve acquired in the past under the same conditions may be used as the reference value.

In the substrate processing method (M), a threshold value (first threshold value for the opening degree of the valve) for determining whether or not the substrate is normally cooled during the processing of the substrate is set in advance. The first threshold is included in the recipe data for production. Details of the recipe data for production will be described later. The first threshold value may be a lower limit value and / or an upper limit value of the valve opening degree. Typically, the valve opening changes due to the leakage of cooling gas from between the substrate and the stage, and the valve opening decreases as the amount of leakage of the cooling gas increases. Therefore, usually, at least a lower limit value is set as the first threshold value. In the threshold value changing step (iii), the first threshold value is changed to the second threshold value based on the amount of change calculated in the calculation step (ii). The formula for changing may be selected according to the conditions. An example of such an equation will be described in Embodiment 1.

In the substrate processing step (iv), the substrate is processed while cooling the substrate with the cooling gas supplied by the cooling gas supply unit. In the substrate processing step (iv), whether or not the substrate is normally cooled is determined based on the opening degree of the valve and the second threshold value. One of the reasons why the board is not cooled normally is that the board is not properly fixed to the stage. If the substrate is not properly fixed to the stage, cooling gas will flow into the decompressed substrate processing chamber. As a result, normal cooling may not be possible, and substrate processing may not be performed normally. Further, the substrate processing may be affected by the flow of a cooling gas other than the substrate processing gas into the substrate processing chamber.

When it is determined that the substrate is not cooled normally, for example, the processing of the substrate may be stopped, the fixed state of the substrate may be corrected, and the processing of the substrate may be performed again. Alternatively, the processing of the substrate may be stopped, the substrate may be discharged from the substrate processing chamber, and processing of another substrate may be performed.

The substrate processing method (M) may further include a step for determining a reference value (reference value determination step). In the reference value determination step, for example, the valve opening degree acquired in the condition for determining the reference value (for example, the recipe of the acquisition step (i)) may be used as the reference value. Alternatively, the reference value may be set based on the opening degree acquired in the past acquisition step (i). For example, the opening degree acquired in the first acquisition step (i) may be used as a reference value in the next acquisition step (i). In that case, the reference value may be sequentially updated with the opening degree acquired in the acquisition step (i) from the next time onward. Alternatively, the average value of the opening degrees acquired in the past plurality of acquisition steps (i) may be used as the reference value. Alternatively, the average value of the openings acquired in the acquisition step (i) performed during the past fixed period may be used as the reference value.

In the method (M), the substrate may be treated with plasma in the substrate processing step (iv). Examples of plasma processing include plasma etching, plasma ashing, film formation (plasma CVD, etc.), modification of the substrate surface using plasma, cleaning of the substrate surface using plasma, and the like. Examples of plasma etching include plasma dicing that cuts the substrate. The conditions for these substrate treatments are not particularly limited, and may be carried out under known conditions. When plasma treatment is performed, a gas according to the purpose is introduced into the substrate processing chamber (chamber), and an electric field and / or a magnetic field is applied to the gas from the electrodes. When the substrate processing is plasma etching, a gas for plasma etching is introduced into the substrate processing chamber. For example, when plasma etching a silicon layer or a silicon substrate, a fluorine-containing gas or the like may be used. Examples of fluorine-containing gases include CF ₄ , CHF ₃ , XeF ₂ , XeF ₆ , sulfur hexafluoride gas (eg SF ₆ ) and the like.

The valve may be a piezo valve or another valve. Examples of valves other than piezo valves include valves used for pressure regulation of vacuum devices. Examples of such valves include, for example, butterfly valves.

At least a part of the decompression device for depressurizing the substrate processing chamber may be used as an exhaust device arranged on the downstream side of the valve. In this case, the substrate processing device includes a device that functions as both an exhaust device and a decompression device. In this case, all of the decompression devices may be used as an exhaust device for cooling gas. Alternatively, a part of the decompression device may be used as an exhaust device for cooling gas. For example, when the decompression device includes a vacuum pump and a low vacuum pump arranged on the downstream side of the vacuum pump, a flow path of cooling gas (a flow path on the downstream side of the valve) may be connected between them. In this case, the low vacuum pump functions as an exhaust device for the gas flow path. The low vacuum pump is a pump (for example, a diffusion pump) used for depressurization in a high pressure region as compared with an upstream vacuum pump (high vacuum pump).

The substrate processing step (iv) may include a plurality of processing steps having different processing conditions. A first threshold value may be set for each processing condition of the plurality of processing steps. In the threshold value changing step (iii), the first threshold value for each processing step may be changed to the second threshold value based on the value (change amount) indicating the above change.

Usually, in the method (M), a plurality of substrates are processed by performing the process group including the steps from the acquisition step (i) to the substrate processing step (iv) a plurality of times. One step group usually includes an acquisition step (i), a calculation step (ii), a threshold change step (iii), and a substrate processing step (iv) in this order.

Each of the plurality of process groups may further include a step of acquiring update necessity information regarding whether or not the threshold value changing step (iii) needs to be performed before the threshold value changing step (iii). Then, when the update necessity information that the threshold value changing step (iii) needs to be performed is acquired in each of the plurality of process groups, the threshold value changing step may be performed. The update necessity information is input by the user of the device. According to this configuration, the acquisition step (i) to the threshold value change step (iii) need to be performed only when the user determines that the threshold value needs to be changed. Therefore, according to this configuration, it is possible to shorten the time required for substrate processing.

The manufacturing method (M) is a determination step of determining whether the acquisition step (i) is correctly performed by using the opening degree acquired in the acquisition step (i) of the previous process group in the second and subsequent process groups. May be further included. For example, in the determination step, the opening degree acquired in the acquisition step (i) of the previous process group and the opening degree acquired in the acquisition step (i) of the current process group are used to obtain the current acquisition step ( It may be determined whether i) is performed correctly.

(Board processing equipment)
The apparatus according to the present disclosure is an apparatus for processing a substrate. Hereinafter, the device may be referred to as a "board processing device (D)" or a "device (D)". The apparatus (D) can be used in the substrate processing method (M) described above. Since the matters described for the method (M) and the matters described for the substrate processing apparatus used in the method (M) can be applied to the apparatus (D), duplicate explanations may be omitted. The matters described for the apparatus (D) can be applied to the method (M) and the substrate processing apparatus used therein.

The substrate processing apparatus (D) is between a substrate processing chamber, a stage on which the substrate is placed, which is arranged in the substrate processing chamber, a fixing means for fixing the substrate to the stage, and the stage and the substrate. It includes a cooling gas supply unit for supplying cooling gas to the space, a decompression device for depressurizing the substrate processing chamber, and a control unit for controlling the fixing means and the cooling gas supply unit. The cooling gas supply unit includes a gas flow path connected to the above space, a flow controller that controls the flow rate of the cooling gas supplied to the gas flow path, and a pressure gauge that measures the pressure of the cooling gas in the gas flow path. It includes a valve that adjusts the pressure of the cooling gas in the gas flow path according to the opening degree, and an exhaust device arranged on the downstream side of the valve.

Since the configurations other than the control unit have been described above, duplicate description will be omitted. The control unit executes the acquisition step (i), the calculation step (ii), the threshold value changing step (iii), and the substrate processing step (iv) in this order. The control unit determines whether or not the substrate is normally cooled in the substrate processing step based on the opening degree of the valve and the second threshold value. Since the acquisition step (i), the calculation step (ii), the threshold value changing step (iii), and the substrate processing step (iv) are the same as the steps described with respect to the substrate processing method (M), duplicate description is omitted. ..

The control unit includes an arithmetic processing device and a storage device. As the arithmetic processing device and the storage device, those used in a known control unit can be used. However, the processing (program stored in the storage device) executed by the arithmetic processing device is different from the known control unit.

The storage device of the control unit stores programs and data necessary for executing the above steps. The data stored in the storage device includes, for example, recipe data. To execute the above process by the control unit, the control unit acquires and / or outputs data so that the above process is performed, and the control unit sends the device (D) so that the above process is performed. It includes controlling the included equipment, and so on.

For example, the acquisition step (i) and the substrate processing step (iv) are executed by the control unit controlling the equipment included in the apparatus (D) according to the recipe data. The recipe data includes production recipe data, reference value creation recipe data, and the like. The production recipe data is data describing a method of processing a substrate of a certain substrate type by a certain substrate processing apparatus, and is prepared according to the substrate to be processed and the processing content. Therefore, there are various recipe data for production. The production recipe data may be created each time the type of substrate to be processed and the machine number of the substrate processing apparatus are newly specified. The recipe data for creating a reference value is data describing a method of acquiring a valve opening degree with a certain substrate processing device. The recipe data for creating the reference value includes information on the pressure and the gas flow rate when acquiring the valve opening degree.

From one viewpoint, it can be considered that the control unit performs control in the board processing mode (board processing process), control in the calibration mode, and control in the reference value creation mode (reference value determination process). be. The production recipe data holds information on the pressure and the flow rate in the step of processing the substrate and the step of calibrating the opening degree. In the board processing mode, the board is processed according to the board processing step of the recipe data for production. At that time, the control unit cools the substrate by the cooling gas supply unit and determines whether or not the substrate is normally cooled by the cooling gas supply unit based on the valve opening and the threshold value. Process the substrate. In the calibration mode, when the substrate is fixed to the stage and the flow rate of the cooling gas is set to a predetermined flow rate, the pressure (P) becomes a predetermined pressure according to the opening calibration step of the production recipe data. The opening degree of the valve is acquired, and the threshold value is calibrated based on the opening degree.

As described above, the control unit may determine the reference value by executing the step for determining the reference value. In the substrate processing step, the substrate may be treated with plasma. The valve may be a piezo valve. At least a part of the decompression device may be used as the exhaust device.

Hereinafter, examples of the embodiments according to the present disclosure will be specifically described with reference to the drawings. The above-mentioned components can be applied to the components of the methods and devices described below. Further, the methods and devices described below can be modified based on the above description. Further, the matters described below may be applied to the above-described embodiment. Further, in the embodiments described below, components that are not essential to the methods and devices of the present disclosure may be omitted.

(Embodiment 1)
In the first embodiment, an example of the substrate processing method and the substrate processing apparatus according to the present disclosure will be described. In the first embodiment, a case where the substrate processing is a plasma processing will be described.

The substrate processing apparatus 100 of the first embodiment is shown in FIG. The apparatus 100 includes a chamber (base processing chamber) 110, a first electrode 121, a first high frequency power supply 122, a second high frequency power supply 123, a substrate stage 130, a cooling gas supply unit 150, a refrigerant circulation device 161 and a decompression device 162, and a DC power supply. 163, a gas flow rate control unit 170, and a control unit 180 are included. The device 100 may include other devices (not shown). For example, the device 100 may include a pressure gauge for measuring the pressure in the chamber 110, a matching circuit connected to a high frequency power supply, and the like. It is possible to change these devices and configurations (including arrangements) as long as the methods of the present disclosure can be implemented. Since it is possible to apply a known device to the device included in the device 100, detailed description thereof will be omitted. However, the characteristic part of the present disclosure may have a configuration different from that of a known device.

The chamber 110 is a chamber capable of keeping the inside in a decompressed state. The chamber 110 includes a gas introduction port 110a, a gas exhaust port 110b, and a dielectric window 111. The dielectric window 111 is made of a dielectric (for example, aluminum nitride, alumina, quartz, etc.). The first electrode 121 is arranged adjacent to the dielectric window 111. The first electrode 121 is connected to the first high frequency power supply 122. The chamber 110 further includes an opening / closing mechanism (not shown) to allow loading and unloading of the substrate 10.

A gas source 202 (for example, a gas cylinder) is connected to the gas introduction port 110a via a gas flow rate control unit 170. The gas flow rate control unit 170 controls the flow rate of the gas supplied from the gas source 202. The gas whose flow rate is controlled is supplied into the chamber 110 from the gas introduction port 110a. For example, a mass flow controller (MFC) can be used for the gas flow rate control unit 170. The gas source 202 is a source of gas (GAS) required to generate plasma in the chamber to process the substrate 10. Although FIG. 1 shows an example in which three types of gas are used, the number of gas and the number of devices for controlling the flow rate thereof are changed according to the treatment.

The gas exhaust port 110b is connected to the decompression device 162. The pressure reducing device 162 decompresses the inside of the chamber 110 to a pressure lower than the atmospheric pressure. Specifically, the depressurizing device 162 adjusts the pressure in the chamber 110 to a pressure suitable for plasma processing. The decompression device 162 includes a vacuum pump. The decompressor 162 may include a valve for adjusting the pressure in the chamber 110.

The substrate 10 processed by the apparatus 100 is arranged on the substrate stage 130. The substrate stage 130 includes an electrode plate 131, an insulating layer 132, and an ESC electrode (electrostatic chuck electrode) 133 arranged in the insulating layer 132. The electrode plate 131 is connected to the second high frequency power supply 123 and functions as an electrode for applying a bias voltage.

The electrode plate 131 is made of a material having high thermal conductivity (for example, metal, specifically aluminum or alumite). Inside the electrode plate 131, a flow path 130h for flowing a refrigerant is formed. The refrigerant circulation device 161 has a function of circulating the refrigerant in the flow path 130h and cooling the refrigerant. As a result, the entire substrate stage 130 can be efficiently cooled. That is, the electrode plate 131 functions as a cooling layer.

The ESC electrode 133 is an electrode for fixing the substrate 10 to the substrate stage 130 by electrostatic adsorption. The ESC electrode 133 is connected to the DC power supply 163. When the electrostatic adsorption is a unipolar electrostatic adsorption, the DC power supply 163 may include one DC power supply. When the method of electrostatic adsorption is bipolar electrostatic adsorption, the ESC electrode 133 includes a pair of electrodes and the DC power supply 163 includes two DC power sources. One of the two DC power supplies is connected to one of the pair of electrodes and the other of the two DC power supplies is connected to the other of the pair of electrodes. The substrate 10 may be mechanically fixed to the substrate stage 130 instead of electrostatic adsorption. In that case, the device 100 includes a fixture (such as a clamp) and a moving device for moving the fixture instead of the ESC electrode 133 and the DC power supply 163.

A top view of an example of the substrate stage 130 is schematically shown in FIG. The substrate stage 130 has an annular protrusion 130p. The annular protrusion 130p has a shape that is the same as or slightly smaller than the outer edge of the substrate 10. The shape of the convex portion 130p may be a shape corresponding to the shape of the outer edge of the substrate 10. The substrate 10 is arranged on the convex portion 130p. As a result, there is a space S (cooling space) between the substrate stage 130 and the substrate 10. An island-shaped convex portion for supporting the substrate 10 may be formed inside the convex portion 130p. The space S is in an airtight state when the substrate 10 and the convex portion 130p are brought into close contact with each other by the ESC electrode 133.

A gas supply port 151h to which a cooling gas is supplied is formed in a portion of the substrate stage 130 facing the space S. That is, the gas flow path 151 is connected to the space S. FIG. 2 shows an example in which a plurality of gas flow paths 151a in which the gas flow path 151 is branched are connected to the space S.

The cooling gas supply unit 150 includes a gas flow path 151, a flow rate controller 152, a pressure gauge 153, a valve 154, and an exhaust device 155. The gas flow path 151 is a flow path through which the cooling gas flows, and means a flow path between the flow rate controller 152, the valve 154, and the space S.

The cooling gas is supplied from a cooling gas source (for example, a gas cylinder) 201, and the flow rate is controlled by the flow rate controller 152. The cooling gas that has passed through the flow rate controller 152 is supplied to the space S through the gas flow path 151. The pressure gauge 153 measures the pressure of the cooling gas in the gas flow path 151 between the flow controller 152, the valve 154, and the space S, and outputs the measurement result to the control unit 180. The exhaust device 155 is arranged on the downstream side of the valve 154, and exhausts the cooling gas in the gas flow path 151 to the outside of the gas flow path 151.

The valve 154 may be a piezo valve. The valve 154 adjusts the pressure (P) of the cooling gas in the gas flow path 151 according to the opening degree thereof. For example, if the opening degree of the valve 154 is increased in a normal operating state, the amount of cooling gas exhausted by the exhaust device 155 increases, so that the pressure (P) decreases. On the other hand, if the opening degree of the valve 154 is reduced in a normal operating state, the amount of exhausted cooling gas is reduced, so that the pressure (P) rises.

As described above, at least a part of the decompression device 162 may be used as an exhaust device. FIG. 3 shows a part of an example of the device 100 in that case. The decompression device 162 of the apparatus of FIG. 3 includes a high vacuum pump 162a such as a turbo molecular pump and a low vacuum pump 162b such as a diffusion pump. The gas flow path on the downstream side of the valve 154 is connected to the flow path (exhaust system) between the high vacuum pump 162a and the low vacuum pump 162b. In this configuration, the low vacuum pump 162b functions as the exhaust device 155 of the gas flow path 151. In this case, since it is not necessary to provide an exhaust device separately from the decompression device 162, the configuration of the device can be simplified.

The control unit 180 is connected to a device that requires control, and performs the control necessary for plasma processing. In FIG. 1, the connection between the control unit 180 and the device is omitted. The control unit 180 includes, for example, a first high frequency power supply 122, a second high frequency power supply 123, a cooling gas supply unit 150 (flow rate controller 152, pressure gauge 153, valve 154, exhaust device 155), a refrigerant circulation device 161 and a decompression device 162. It may be connected to a DC power supply (fixing means) 163 and a gas flow rate control unit 170. The control unit 180 may send and receive signals to and from those devices, control the devices, and receive measurement data.

Hereinafter, an example of plasma processing using the apparatus 100 will be described. First, the substrate 10 is placed on the substrate stage 130. Next, the acquisition step (i) is performed. Specifically, the control unit 180 controls the flow rate controller 152 to set the flow rate of the cooling gas to a predetermined flow rate. Further, the control unit 180 increases the opening degree of the valve 154 when the pressure (P) is higher than the predetermined pressure P1, and reduces the opening degree of the valve 154 when the pressure (P) is lower than the predetermined pressure P1. The valve 154 is controlled so as to be. The increase / decrease in the opening degree of the valve 154 is performed, for example, by changing the voltage applied to the valve 154.

In the acquisition step (i), gas may be introduced from the gas introduction port 110a and decompression in the chamber 110 by the decompression device 162 may be performed so that the pressure in the chamber 110 is also predetermined. At this time, the pressure in the chamber 110 is usually lower than the pressure (P). Further, the substrate 10 is fixed to the substrate stage 130 by the ESC electrode 133. At this time, when it is necessary to charge the substrate 10 for electrostatic adsorption, a process of charging the substrate 10 (for example, a charge process using plasma) is performed.

In order to make an appropriate determination, it is preferable to set the predetermined pressure P1 to a value that is not significantly different from the set pressure Pt of the cooling gas of the gas flow path 151 at the time of the subsequent substrate processing. For example, the predetermined pressure P1 may be 0.5 times or more the minimum value of the set pressure Pt, and the predetermined pressure P1 may be 2 times or less the maximum value of the set pressure Pt. The set pressure Pt at the time of substrate processing may include a plurality of pressures. For example, when the substrate treatment includes a plurality of treatments having different conditions, the set pressure Pt may be changed according to the treatments.

The control unit 180 may acquire the opening degree of the valve 154 when the pressure (P) is determined to be constant by controlling the valve 154 as described above. For example, it may be determined that the pressure (P) becomes constant when a predetermined time elapses after the cooling gas is flowed at a predetermined flow rate and the control of the opening degree of the valve 154 is started. Alternatively, it may be determined that the time when the fluctuation range of the pressure (P) becomes smaller than the predetermined value is the time when the pressure (P) becomes constant. The valve 154 outputs the opening degree to the control unit 180. The control unit 180 acquires the opening degree R1 of the valve 154 when it is determined that the pressure (P) has reached a predetermined pressure. For example, the opening degree R1 may be measured at a plurality of timings to obtain the minimum value of the opening degree R1 or the average value of the opening degree R1.

If the opening degree R1 acquired in the acquisition step (i) has a significantly different value from the opening degree acquired under the same conditions in the past, it may not have been acquired correctly, and an error is notified. You may. For example, if the difference between the opening degree R1 and the opening degree acquired in the past under the same conditions exceeds the permissible value, an error may be notified. The permissible value can be appropriately set according to the state of the device, and may be in the range of, for example, 2 to 3%.

The opening degree of the valve 154 according to the pressure (P) may be controlled by a control unit attached to the valve 154 (hereinafter, may be referred to as "control unit A"). In this case, the control unit 180 outputs a predetermined pressure P1 to the control unit A. The pressure gauge 153 outputs the measured pressure to the control unit A. The control unit A adjusts the opening degree of the valve 154 based on the input pressure P1 and the measured pressure. The valve 154 outputs the value of the opening degree to the control unit 180. In this way, the control unit 180 acquires the opening degree of the valve 154 when it is determined that the pressure (P) is constant. In this case, the control unit A can be regarded as a part of the control unit 180.

Next, the control unit 180 calculates a value (change amount C) indicating a change in the opening degree R1 with respect to the reference value R0 by comparing the opening degree R1 acquired in the acquisition step (i) with the reference value R0. (Calculation step (ii)). The reference value R0 is a reference value of the opening degree of the valve 154 and is stored in the storage device of the control unit 180. For the reference value R0, for example, the opening degree of the valve 154 when the control is performed under the same conditions as the acquisition condition of the opening degree R1 in the past can be used. That is, the opening degree acquired in the past acquisition step (i) can be used as the reference value R0.

The amount of change C in the calculation step (ii) may be the difference between the opening degree R1 (%) and the reference value R0 (%), or is calculated from the opening degree R1 (%) and the reference value R0 (%). It may be another value (for example, a ratio of both).

Next, the control unit 180 changes the first threshold value T1 (%) of the opening degree of the valve 154 to the second threshold value T2 (%) based on the change amount C (threshold value changing step (iii)). The first threshold value T1 is a preset threshold value for determining whether or not the substrate 10 is normally cooled during the processing of the substrate 10. The first first threshold value T1 is, for example, a value preset by the user and stored in the storage device of the control unit 180. As a result, it is possible to determine whether or not the product is normally cooled in the substrate processing step (iv) without changing the content of the production recipe data (first threshold value T1 of the opening degree) due to secular variation or the like. can.

When the amount of change C (value indicating the change) is the difference between the opening degree R1 and the reference value R0, the difference may be added to the first threshold value T1 to obtain the second threshold value T2. In that case, T2 (%) = T1 + (R1-R0). When the amount of change C is the ratio of the opening degree R1 to the reference value R0, the first threshold value T1 may be multiplied by the ratio to obtain the second threshold value T2. T2 (%) = T1 × (R1 / R0). It should be noted that these are examples, and other equations capable of appropriately changing the second threshold value T2 may be used. The change amount set here can be used as the change amount in the threshold value changing step (iii) of the next step group (next step (i) to step (iv)).

Next, the control unit 180 executes the substrate processing step (iv) of processing the substrate 10 while cooling the substrate 10 with the cooling gas supplied by the cooling gas supply unit 150. Specifically, the control unit 180 controls the cooling gas supply unit 150 so that the pressure (P) is set in advance. At this time, the opening degree of the valve is output from the valve 154 to the control unit 180. Further, the control unit 180 controls the equipment required for processing the substrate 10. For example, the control unit 180 introduces the gas required for plasma processing from the gas source 202 into the chamber 110 at a predetermined flow rate. Further, the control unit 180 controls the decompression device 162 to set the pressure inside the chamber 110 to a predetermined pressure. Further, the control unit 180 generates plasma by controlling the first high frequency power supply 122 (and the second high frequency power supply 123 if necessary), thereby plasma-treating the substrate 10.

The pressure in the chamber 110 in step (iv) varies depending on the treatment, but may be in the range of, for example, 0.3 Pa to 12 Pa. The pressure in the gas flow path 151 in the step (iv) may be in the range of, for example, 400 Pa to 3000 Pa.

In the substrate processing step (iv), the control unit 180 determines whether or not the substrate 10 is normally cooled based on the opening degree of the valve 154 and the second threshold value T2. For example, when the opening degree of the valve 154 output from the valve 154 deviates from the range defined by the second threshold value T2 (the range determined to be normal), the control unit 180 is normally cooled. It is determined that there is no such thing. For example, when the second threshold value T2 is the lower limit value of the opening degree and the opening degree of the valve 154 is lower than the second threshold value T2, the control unit 180 determines that cooling is not normally performed. If it is determined that the cooling is not normally performed, the control unit 180 can stop the processing of the substrate 10. After the processing of the substrate 10 is stopped, the state of the apparatus 100 may be inspected, the substrate 10 may be remounted on the stage 130, and the processing of the substrate 10 may be performed again. Alternatively, the substrate 10 may be replaced to process another substrate 10. This makes it possible to suppress processing defects of the substrate 10. In addition, the time for improper substrate processing can be reduced.

As described above, the substrate can be processed. In the apparatus 100, a plurality of substrates 10 can be processed by performing the process group including the steps from the acquisition step (i) to the substrate processing step (iv) a plurality of times. In this case, as described above, the threshold value changing step may be performed only when there is a request from the user. In that case, the control unit 180 acquires update necessity information regarding whether or not it is necessary to perform the threshold value changing step (iii) before the threshold value changing step (iii) in each of the plurality of process groups. Then, when the update necessity information that the threshold value changing step (iii) needs to be performed is acquired in each of the plurality of process groups, the control unit 180 performs the threshold value changing step (iii). Further, even when the threshold value changing step (iii) is not performed, the acquisition step (i) may be performed. Further, the calculation step (ii) may be performed. The opening degree in the acquisition step (i) and the amount of change in the calculation step (ii) are stored, and the influence of the secular change of the apparatus 100 can be inferred.

An example of the method of the first embodiment is shown in Table 1. For ease of understanding, the numerical values in the columns that are not necessary for explanation and the numerical values in the columns that do not have the corresponding numerical values are omitted.

The above manufacturing method includes a reference value determination step and three step groups. Step 1 corresponds to the preparation step, step 2 corresponds to the acquisition process, and steps 3 and 4 correspond to the substrate processing process. The conditions for each step are defined in the process recipe set by the user in advance. When the processing of the substrate in the process group 1 is completed, a new substrate is processed in the next process group 2. In this way, a plurality of substrates are processed. Note that step 1, which is a preparation step, includes a step of flowing gas into the gas flow path under predetermined conditions.

In the manufacturing method shown in Table 1, first, the reference value determination step is performed with the substrate fixed to the stage. In the reference value determination step, the valve opening degree at the gas flow rate and the pressure (P) determined by the process recipe is acquired. The valve opening degree B (57 in Table 1) acquired in step 2 of the reference value determining step becomes the reference value A of the valve opening degree in the subsequent process groups 1 to 3. Also in step 2 of the next step group 1, the valve opening degree B (59 in Table 1) at the gas flow rate and pressure (P) determined by the process recipe is acquired. Then, in the process group 1, the amount of change C (+2 in Table 1) is calculated. Using this amount of change C, the preset first threshold value T1 of step 3 and step 4 is changed to the second threshold value T2. In this example, the second threshold value T2 is obtained by adding the change amount C to the first threshold value T1. In the next steps 3 and 4, the substrate processing is performed. At the time of substrate processing, the control unit monitors whether the valve opening degree B is below the second threshold value T2, thereby determining whether or not the substrate is normally cooled. When the substrate processing is finished, the processed substrate is removed from the chamber. Next, a new substrate is carried into the chamber, and process group 2 is performed. After that, the same processing as in step group 1 is performed. In this way, the processing of a plurality of substrates is performed.

In each process group, a determination step for determining whether or not the current acquisition step is correctly performed may be performed using the opening degree B acquired in the previous step 2 (acquisition step). In the example shown in Table 1, the lower limit value Z of the valve opening degree in step 2 is set in each process group. When the valve opening degree B acquired in the acquisition process is less than the lower limit value Z, it is determined that the acquisition process is not performed correctly, and an error is notified. In the case of the example shown in Table 1, the lower limit value Z is a value obtained by subtracting the value α indicating the allowable range (2 in the example of Table 1) from the valve opening degree B acquired in the previous step 2. According to this configuration, it can be determined whether or not the acquisition process is performed correctly. If it is determined that the acquisition process is not performed correctly, the subsequent substrate processing may be stopped.

FIG. 4 shows a flowchart schematically showing a part of the method of Table 1. The flowchart of FIG. 4 shows one process group after the process group 2. First, the valve opening degree B is acquired by the acquisition step (i) (step S101). Next, it is determined whether or not the acquired opening degree B is equal to or greater than the set lower limit value Z (step S102). If the opening degree B is equal to or higher than the set lower limit value Z, the process proceeds to the next step S103, and if not, an error is notified (step S106). In step S103, the amount of change C is calculated by the calculation step (ii). Next, the threshold value is changed by the threshold value changing step (iii) (step S104). Next, the substrate is processed in the substrate processing step (iv) (step S105). In the substrate processing step (iv), the substrate is normally cooled by using the threshold value changed in the threshold value changing step (iii) and the opening degree measured during the substrate processing step (iv). Whether or not it is determined. If it is determined that the substrate has not been cooled normally, an error is notified and the substrate processing is stopped if necessary. If no error is notified, the substrate processing step (iv) is performed until the substrate processing is completed. In this way, one process group is executed.

The present disclosure can be applied to a substrate processing method and a substrate processing apparatus.

10: Substrate 100: Substrate processing device 110: Chamber (board processing chamber)
130: Board stage (stage)
130h: Flow path 150: Cooling gas supply unit 151: Gas flow path 152: Flow rate controller 153: Pressure gauge 154: Valve 155: Exhaust device 162: Decompression device 180: Control unit S: Space

Claims (14)

It is a board processing method using a board processing device.
The substrate processing device is
Board processing room and
A stage on which a substrate is placed and arranged in the substrate processing chamber, and a stage on which the substrate is placed.
A fixing means for fixing the substrate to the stage,
A cooling gas supply unit for supplying cooling gas to the space between the stage and the substrate,
A decompression device for decompressing the substrate processing chamber, and the like.
The cooling gas supply unit is
The gas flow path connected to the space and
A flow rate controller that controls the flow rate of the cooling gas supplied to the gas flow path,
A pressure gauge that measures the pressure of the cooling gas in the gas flow path,
A valve that adjusts the pressure of the cooling gas in the gas flow path according to the opening degree,
Including an exhaust device located on the downstream side of the valve.
The substrate processing method is
An acquisition step of acquiring the opening degree of the valve when the pressure becomes a predetermined pressure while the substrate is fixed to the stage and the flow rate is set to a predetermined flow rate.
A calculation step of calculating a value indicating a change in the opening degree with respect to the reference value by comparing the opening degree acquired in the acquisition step with a reference value.
The first threshold value of the opening degree of the valve, which is preset to determine whether or not the substrate is normally cooled during the processing of the substrate, is set based on the value indicating the change. The threshold change process for changing to the second threshold, and
A substrate processing step of processing the substrate while cooling the substrate with the cooling gas supplied by the cooling gas supply unit is included.
A substrate processing method in which, in the substrate processing step, whether or not the substrate is normally cooled is determined based on the opening degree of the valve and the second threshold value. The substrate processing method according to claim 1, further comprising a step for determining the reference value. The substrate processing method according to claim 1 or 2, wherein the substrate is treated with plasma in the substrate processing step. The substrate processing method according to any one of claims 1 to 3, wherein the valve is a piezo valve. The substrate processing method according to any one of claims 1 to 4, wherein at least a part of the decompression device is used as the exhaust device. The substrate processing step includes a plurality of processing steps having different processing conditions.
The first threshold value is set for each processing condition of the plurality of processing steps.
The substrate according to any one of claims 1 to 5, wherein in the threshold value changing step, the first threshold value for each processing step is changed to the second threshold value based on the value indicating the change. Processing method. The substrate processing method according to any one of claims 1 to 6, wherein a plurality of the substrates are processed by performing a process group including the steps from the acquisition step to the substrate processing step a plurality of times. Each of the plurality of process groups further includes a step of acquiring update necessity information regarding whether or not the threshold value change step needs to be performed before the threshold value change step.
The substrate processing method according to claim 7, wherein the threshold value changing step is performed when the update necessity information that the threshold value changing step needs to be performed is acquired in each of the plurality of process groups. 7. 8. The substrate processing method according to 8. It is a board processing device that processes boards.
Board processing room and
A stage on which the substrate is placed and arranged in the substrate processing chamber, and a stage on which the substrate is placed.
A fixing means for fixing the substrate to the stage,
A cooling gas supply unit for supplying cooling gas to the space between the stage and the substrate,
A decompression device for decompressing the substrate processing chamber and
The fixing means and the control unit for controlling the cooling gas supply unit are included.
The cooling gas supply unit is
The gas flow path connected to the space and
A flow rate controller that controls the flow rate of the cooling gas supplied to the gas flow path,
A pressure gauge that measures the pressure of the cooling gas in the gas flow path,
A valve that adjusts the pressure of the cooling gas in the gas flow path according to the opening degree,
Including an exhaust device located on the downstream side of the valve.
The control unit
An acquisition step of acquiring the opening degree of the valve when the pressure becomes a predetermined pressure while the substrate is fixed to the stage and the flow rate is set to a predetermined flow rate.
A calculation step of calculating a value indicating a change in the opening degree with respect to the reference value by comparing the opening degree acquired in the acquisition step with a reference value.
The first threshold value of the opening degree of the valve, which is preset to determine whether or not the substrate is normally cooled during the processing of the substrate, is set based on the value indicating the change. The threshold change process for changing to the second threshold, and
A substrate processing step of processing the substrate while cooling the substrate with the cooling gas supplied by the cooling gas supply unit is executed.
The control unit is a substrate processing apparatus that determines whether or not the substrate is normally cooled in the substrate processing step based on the opening degree of the valve and the second threshold value. The substrate processing apparatus according to claim 10, wherein the control unit determines the reference value by executing a step for determining the reference value. The substrate processing apparatus according to claim 10 or 11, wherein the substrate is treated with plasma in the substrate processing step. The substrate processing apparatus according to any one of claims 10 to 12, wherein the valve is a piezo valve. The substrate processing device according to any one of claims 10 to 13, wherein at least a part of the decompression device is used as the exhaust device.

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