JP6638576B2 - Vacuum processing device, vacuum processing method, and storage medium - Google Patents

Description

  The present invention relates to a technique for controlling the pressure in a processing container when performing a predetermined vacuum processing on an object to be processed in the processing container.

  In a manufacturing process of an FPD (flat panel display) substrate, there is a process of performing a predetermined vacuum process such as an etching process or a film forming process on a target object under a reduced pressure atmosphere. In these steps, for example, a mounting table for mounting an object to be processed, such as an FPD substrate (hereinafter, referred to as “substrate”), is provided inside a processing container, and a vacuum provided with a gas supply unit facing the mounting table. The processing is performed in the processing device. For example, in a vacuum processing apparatus, a processing gas is supplied from a gas supply unit by evacuating the processing container, and high-frequency power is applied to a gas supply unit also serving as an upper electrode, thereby forming plasma to perform processing. Will be

  In such a vacuum processing apparatus, various processes having different processing conditions such as the flow rate of the processing gas and the pressure in the processing vessel are performed, and it is required to stably control the pressure in a wide pressure range. In Patent Document 1, a plurality of exhaust paths connected to a vacuum pump are provided in a vacuum chamber, and a semi-fixed valve whose opening is fixed in three stages is provided in several of these exhaust paths, and the remaining exhaust paths are provided. Discloses a configuration in which an automatic pressure control valve is provided. In this configuration, the pressure setting value and the opening degree of the semi-fixed valve are described in association with the recipe, and the pressure setting value is read by selecting the recipe to set the opening degree of the semi-fixed valve. The opening of the automatic pressure control valve is adjusted based on the pressure set value and the detected pressure value, and pressure control is performed.

  According to Patent Literature 1, stable pressure control can be performed in a wider range than in the past by using a combination of an automatic pressure control valve and a semi-fixed valve. However, the automatic pressure control valve has a limited pressure adjustment range due to its mechanism, and the semi-fixed valve has an opening set in advance in association with a pressure set value. However, there is an area where the pressure cannot be adjusted. On the other hand, there is a request from the user of the apparatus to perform processing under process conditions different from the recipe stored in the apparatus in advance due to diversification of products, but in such a case, there is a concern that stable pressure control may not be performed. Further improvement is required.

Japanese Patent No. 5322254 (see paragraphs 0034 and 0037)

  The present invention has been made under such circumstances, and an object of the present invention is to provide a technique capable of performing stable pressure control in a wide pressure range.

For this reason, the vacuum processing apparatus of the present invention
A processing container in which vacuum processing is performed on the object to be processed,
A first exhaust path and a second exhaust path each having one end connected to the processing container,
A pressure detector for detecting the pressure in the processing container,
An automatic adjustment valve that is provided in the first exhaust path and that automatically adjusts the conductance of the exhaust path based on a pressure detection value and a pressure set value of the pressure detection unit;
A semi-fixed valve provided in the second exhaust path and set to an opening selected from at least three predetermined openings;
An opening detection unit that detects the opening of the automatic adjustment valve,
When the opening detection value detected by the opening detection unit exceeds a predetermined threshold as a pressure adjustment limit, the opening of the semi-fixed valve is increased in order to extend a pressure adjustment range. And a control unit that outputs a control signal so as to change the opening to another opening among the openings.

Further, the vacuum processing method of the present invention,
In a method for performing vacuum processing on an object to be processed in a processing vessel to which a first exhaust path and a second exhaust path are connected,
A step of loading the object to be processed into the processing container;
The semi-fixed valve, which is provided in the second exhaust path and is set to an opening selected from at least three predetermined openings, is provided with a pressure setting value for performing vacuum processing and a processing container. Setting the opening determined according to the combination with the flow rate set value of the gas supplied into,
Thereafter, a step of performing vacuum processing while automatically adjusting an opening degree by an automatic adjustment valve provided in the first exhaust path so that a pressure detection value in the processing container becomes a pressure set value,
Detecting the opening of the automatic adjustment valve,
When the opening detection value detected in the step exceeds a predetermined threshold as a pressure adjustment limit, the opening of the semi-fixed valve, in order to expand the pressure adjustment range, the predetermined opening of the predetermined opening And changing the opening to another opening.

Further, the storage medium of the present invention
A storage medium storing software used for an apparatus that performs vacuum processing on a processing target in a processing container to which a first exhaust path and a second exhaust path are connected,
The software is characterized by including a computer program in which steps are set to execute the vacuum processing method of the present invention.

  According to the present invention, the first exhaust path and the second exhaust path are connected to the processing container, and the first exhaust path is provided with an automatic adjustment valve, and the second exhaust path is provided with at least three stages of opening. A semi-fixed valve to be selected is provided. The opening of the automatic adjustment valve is automatically adjusted based on the pressure detection value and the pressure set value in the processing container, and the opening of the semi-fixed valve is adjusted based on the opening detection value of the automatic adjustment valve. When the pressure exceeds a predetermined threshold as a pressure adjustment limit, the pressure is automatically changed. Thus, before the pressure control by the automatic adjustment valve becomes ineffective, the opening degree of the semi-fixed valve is automatically changed, so that pressure control can be stably performed in a wide range.

It is a vertical side view which shows one Embodiment of the etching processing apparatus to which the vacuum processing apparatus of this invention is applied. FIG. 3 is a configuration diagram illustrating a control unit of the etching processing apparatus. FIG. 4 is a characteristic diagram illustrating a relationship among opening degrees of a first valve and a second valve, a flow rate of a processing gas, and a pressure in a processing container. 5 is a flowchart showing the operation of the etching apparatus of the present invention. FIG. 4 is a characteristic diagram illustrating a relationship among opening degrees of a first valve and a second valve, a flow rate of a processing gas, and a pressure in a processing container.

  Hereinafter, embodiments of the present invention will be described with reference to an example in which the vacuum processing apparatus of the present invention is applied to an etching apparatus for performing an etching process on a substrate. FIG. 1 is a longitudinal sectional view of the etching apparatus 1. The etching processing apparatus 1 includes a grounded processing container 10 for performing an etching process on a substrate S inside thereof. The substrate S is a square-shaped object to be processed, and the processing container 10 is formed, for example, in a horizontal cross-sectional shape in a square shape, and is made of a material having good heat conductivity such as aluminum (Al). In the figure, reference numeral 11 denotes a transfer port for the substrate S, and reference numeral 12 denotes a gate valve for opening and closing the transfer port 11.

  The mounting table 2 for the substrate S is disposed inside the processing container 10. The mounting table 2 is electrically connected to a high-frequency power supply unit 21 for generating plasma, and functions as a lower electrode for generating plasma in the processing chamber 10. The mounting table 2 is made of, for example, aluminum, and is disposed on the bottom surface of the processing container 10 via an insulating member 22. On the other hand, a gas supply unit 3 also serving as an upper electrode is provided above the mounting table 2 inside the processing container 10 so as to face the mounting table 2. The gas supply unit 3 is made of, for example, aluminum, and has a plurality of gas supply holes 31 formed on the lower surface thereof. The processing container 10 is provided with a gas supply path 32 for supplying a processing gas to the internal space of the gas supply unit 3. The other end of the gas supply path 32 is connected to a processing gas supply source 33. ing. Further, the processing container 10 is provided with a pressure detection unit 14 for detecting the pressure inside the processing container 10.

  A first exhaust path 41 and a second exhaust path 42 are provided on the bottom wall of the processing container 10. Each of the first exhaust path 41 and the second exhaust path 42 is provided in a plurality, for example, three each. For example, the first exhaust path 41 and the second exhaust path 42 are provided on the bottom surface of the processing container 10 along the circumferential direction of the processing container 10. The other end side of each of the first and second exhaust passages 41 and 42 is connected to an exhaust mechanism (not shown) formed of, for example, a vacuum pump. For example, the exhaust mechanism of the first exhaust passage 41 is shared. The exhaust mechanism of the second exhaust path 42 is shared. The first exhaust path 41 is provided with a first valve 51 formed of an automatic adjustment valve, and the second exhaust path 42 is provided with a second valve 52 formed of a semi-fixed valve. Although the first valve 51 and the second valve 52 in FIGS. 1 and 2 are described as representatives, it is assumed that there are similar control lines for each of the valves 51 and 52.

  The first valve 51 is an APC (Adaptive Pressure Controller) valve including a valve body and a controller 50 for adjusting the opening degree of the valve body, and the opening degree is determined based on a pressure detection value of the pressure detection unit 14 and a pressure set value. Is a valve that is automatically adjusted to automatically adjust the conductance of the first exhaust path 41. The opening degrees of the three first valves 51 are automatically adjusted at substantially the same opening degree based on the pressure detection values of the pressure detection unit 14. Therefore, for example, the controller 50 of the first valve 51 of the three first valves 51 functions as an opening detection unit that detects the opening of the first valve 51, and the opening detection unit Is output to the control unit 6 described later.

  The second valve 52 is a valve that is set to an opening selected from at least three predetermined openings. For example, the second valve 52 is a valve whose opening can be freely adjusted by a control signal from the control unit 6, and is constituted by, for example, an APC valve including a valve body and a controller 53 for adjusting the opening of the valve body. For example, the opening of the second valve 52 is preset to an opening selected from the maximum opening, the minimum opening, and the opening between the maximum opening and the minimum opening of the valve. The maximum opening includes an opening that is slightly smaller than the maximum opening of the valve, for example, an opening that is 5% smaller than the maximum opening, and the minimum opening is slightly smaller than the minimum opening of the valve. It also includes an opening that is open, for example, an opening that is 5% larger than the minimum opening. Here, 5% is a value when the maximum opening is 100%. Although the opening between the maximum opening and the minimum opening can be set as appropriate, here, for convenience of explanation, the maximum opening is “fully open”, the minimum opening is “fully closed”, and the maximum opening and the minimum opening are The degree of opening between is defined as “half open”.

  The etching apparatus 1 is configured to be controlled by the control unit 6. As shown in FIG. 2, the control unit 6 includes a CPU 61, a program storage unit 62, a work memory 63, a memory 64, an input unit 65, and a recipe storage unit 66 connected to a bus 60, respectively. Further, a controller 50 of the first valve 51 and a controller 53 of the second valve 52 are connected to the bus 60, respectively. In this way, the opening of one first valve 51 is detected by the controller 50, and the detected value of the opening is output to the control unit 6, and the opening set value is entirely sent from the control unit 6 to the second valve 52. It is configured to be output.

  The CPU 61 performs various calculations for executing a flow of an etching process described later. The program storage unit 62 stores various programs in which commands (each step) for sending a control signal to each unit of the etching processing apparatus 1 and for causing a predetermined etching process to proceed are stored. The memory 64 stores two thresholds of the first valve 51, and the threshold is predetermined as a pressure adjustment limit of the first valve 51.

  The input unit 65 includes a mouse, a keyboard, a touch panel, and the like, and is configured to allow a user of the device to input a threshold value of the first valve 51. The recipe storage unit 66 is a unit that stores process recipes corresponding to various processing processes. For example, for each processing process, a set value of a flow rate of a gas supplied into the processing container 10 when performing vacuum processing, The pressure set value in the container 10 and the initial opening degree of the second valve 52 are described as either “fully open” or “fully closed”. The initial opening degree of the second valve 52 is subjected to an evaluation test in advance, and for example, as shown in FIG. 3, correlation data between the pressure set value in the processing container 10 and the flow rate set value of the processing gas is acquired. Thus, it is determined according to the combination of the pressure set value and the flow rate set value.

  When the detected value of the opening of one first valve 51 detected by the controller (opening detecting unit) 50 exceeds the threshold value, the controller 6 controls the opening of all the second valves 52. Is provided with a program for outputting a control signal so as to change the opening degree to another opening degree. The program has a group of steps so that a flow described later can be executed, and is installed in the control unit 6 from a storage medium such as a hard disk, a compact disk, a magneto-optical disk, a memory card, and a flexible disk.

  As described above, FIG. 3 shows characteristics indicating the relationship among the opening degrees of the first valve 51 and the second valve 52, the flow rate of the processing gas, and the pressure in the processing chamber 10 in the etching processing apparatus 1. FIG. In the figure, the horizontal axis indicates the gas flow rate, and the vertical axis indicates the pressure. In FIG. 3, a first curve A1 indicated by a dashed line is data when all the second valves 52 are “fully closed” and the opening degrees of the first valves 51 are “300”. The second curve A2 indicated by a dotted line is data when all the second valves 52 are “fully open” and the opening degree of the first valves 51 is “1”, and the third curve indicated by a solid line is A3 is data when all the second valves 52 are “fully open” and the opening degrees of the first valves 51 are “300”.

  The opening degrees of the first valve 51 and the second valve 52 are controlled by the controllers 50 and 53 as described above, and “1” and “300” are set values on the controllers 50 and 53. In the controllers 50 and 53, the opening degree of the first and second valves 51 and 52 can be set from "1" to "1000". There is almost no change in pressure in 10. As described above, the opening degree of “1” is extremely close to “fully closed”, and the opening degree of “300” is extremely close to “fully open”. Is described as “fully closed” and an opening degree of “300” or more as “fully opened”.

  In FIG. 3, a region S1 on the left side of the first curve A1 has a pressure higher by setting the second valve 52 to “fully closed” and adjusting the first valve 51 from “fully closed” to “fully open”. This is the area where adjustments can be made. On the other hand, in a region S2 between the second curve A2 and the third curve A3, the second valve 52 is set to “fully open”, and the first valve 51 is adjusted from “fully closed” to “fully open”. Is an area where pressure adjustment can be performed. On the other hand, in a region S3 indicated by a diagonal line between the first curve A1 and the second curve A2, when the second valve 52 is set to “fully open” or “fully closed”, the first valve 51 is switched to “closed”. Even if the adjustment is performed from "fully closed" to "fully opened", the pressure cannot be adjusted.

  The present invention changes the opening of the second valve 52 from "fully closed" or "fully open" to "half open" in order to eliminate the pressure uncontrollable region and expand the pressure adjustment range. The opening of the second valve 52 is changed based on the detected value of the opening of the first valve 51. For this reason, the initial position of the second valve 52 is set in advance to “fully open” or “fully closed”, a threshold value is provided for the opening degree of the first valve 51, and when the threshold value is exceeded, the second valve 52 is opened. It is configured to output a control signal for changing the opening of 52 to “half open”.

  The threshold value of the first valve 51 is predetermined as a pressure adjustment limit. For example, a threshold value (first threshold value) on the side that reduces the opening of the first valve 51 and a threshold value (second threshold value) on the opening side ) Are stored in the memory 64, for example, when the operator inputs from the input unit 65. The first threshold in FIG. 3 is a threshold when moving from the first area S1 side to the third area S3, and is set to, for example, an opening degree selected from the opening degrees “200” to “300”. You. In this case, exceeding the threshold value means that the opening degree of the first valve 51 is larger than the opening degree selected from the opening degrees “200” to “300” that form the first threshold value.

  In addition, the second threshold is a threshold when moving from the second area S2 side to the third area S3 in FIG. 3, and is, for example, an opening selected from the opening “1” to “100”. Is set. In this case, exceeding the threshold value means that the opening degree of the first valve 51 is smaller than the opening degree selected from the opening degrees “1” to “100” forming the second opening degree. The pressure regulation limit is a term used to facilitate understanding of the invention and to simplify the description. Therefore, the present invention is not limited to the case where the pressure adjustment limit is mechanically applied to the valve, but is easily determined by the margin, for example, the opening degree before entering the region where the adjustment sensitivity is deteriorated. This means that the opening degree determined as described above is also included.

  Next, the etching method of the present invention will be described with reference to the flowchart of FIG. First, the control unit 6 selects and reads a target process recipe from the recipe storage unit 66 (step S1). The control unit 6 outputs a control signal to each unit of the etching processing apparatus 1 based on the process recipe, and performs a predetermined etching process on the substrate S. Specifically, the substrate S is carried into the processing container 10 and placed on the placement unit 2, and the gate valve 12 is closed. At this time, the opening degree 52 of the first valve 51 and the second valve is set to “fully open”, and each exhaust mechanism is operated. Next, gas is discharged from the gas supply unit 3 toward the substrate S, and high-frequency power is supplied to the mounting unit 2 from the high-frequency power supply unit 21.

  The pressure control of the processing container 10 will be described. The control unit 6 operates, for example, each exhaust mechanism based on the selected process recipe, and then sets the opening degree of the second valve 52 to the pressure set value and the gas flow rate. The initial opening degree determined according to the combination with the set value is set to “fully closed” or “fully opened”. After that, the control unit 6 outputs the pressure set value described in the process recipe to each controller 50 of the first valve 51, and in each controller 50, the detected pressure value in the processing container 10 is changed to the pressure set value. The opening degree of each first valve 51 is automatically adjusted so that

  Describing a case where the initial opening of the second valve 52 is “fully closed”, it is determined whether or not the opening of the second valve 52 is “fully closed” (step S2). If "closed", the process starts in step S3. That is, a plasma is formed in a space above the substrate S, and the processing gas from the gas supply unit 3 is activated by the plasma to perform an etching process on the substrate S. During the process, the opening of one first valve 51 is constantly detected, and the detected opening is output to the control unit 6. The control unit 6 determines whether or not the opening of the first valve 51 is equal to or smaller than a first threshold (step S4). If the opening is equal to or smaller than the first threshold, the process is continued.

  On the other hand, if the opening degrees of the first valves 51 exceed the first threshold value (if larger than the first threshold value), in step S5, the opening degrees of all the second valves 52 are set to “fully closed”. To “half open”, for example, synchronously and continue the process. When the degree of opening of the second valve 52 is changed from "fully closed" to "half open", the degree of opening of the first valve 51 is reduced from a state close to "fully open" and returned to a state where the pressure can be automatically adjusted. This will be specifically described with reference to FIG. FIG. 5 shows the characteristic diagram of FIG. 3 together with data when the opening of the second valve 52 is “half open”. In FIG. 5, a fourth curve A4 indicated by a two-dot chain line is data when all the second valves 52 are "half open" and the opening degrees of the first valves 51 are "300 (fully open)". is there.

  If the second valve 52 is set to “half open” when the first valve 51 exceeds the first threshold value, the combined exhaust capacity of the first exhaust path 41 and the second exhaust path 42 is improved. The opening of the first valve 51 is once reduced. Then, since the automatic adjustment can be performed again until the opening degree becomes “300”, the area S4 between the first curve A1 and the fourth curve A4 is also an area where the pressure adjustment can be performed. . As described above, since the area S4 covers the area S2, the pressure-adjustable area S2 can be eliminated. Thus, the process is continued while the pressure is automatically adjusted by the first valve 51, and the process is terminated (step S6).

  Subsequently, the case where the initial opening degree of the second valve 52 is “fully open” will be described. If the opening degree of the second valve 52 is “full open” in step S2, the process proceeds to step S7. To start. During the process, the opening of one first valve 51 is constantly detected, and the detected opening is output to the control unit 6. The controller 6 determines whether or not the opening of the first valve 51 is equal to or greater than a second threshold (step S8). If the opening is equal to or greater than the second threshold, the process is continued. On the other hand, if the opening degrees of the first valves 51 exceed the second threshold value (if smaller than the second threshold value), in step S5, the opening degrees of all the second valves 52 are changed from "full open" to "full open". The process is continued, for example, in synchronization with "half open". When the opening degree of the second valve 52 is changed from “full opening” to “half opening”, the exhaust capacity of the first exhaust path 41 and the second exhaust path 42 is reduced. Is opened from a state close to “fully closed”, and the pressure is returned to a state where the pressure can be automatically adjusted. Therefore, the pressure-adjustable region S2 can be eliminated as described above. Thus, the process is continued while the pressure is automatically adjusted by the first valve 51, and the process is terminated (step S6).

  According to the above-described embodiment, the first valve 51 is formed by using the first valve 51 formed of an automatic adjustment valve and the second valve 52 formed of a semi-fixed valve selected from at least three degrees of opening. Is detected, and when the pressure exceeds a predetermined threshold as a pressure adjustment limit, the opening of the second valve 52 is automatically changed. As a result, before the pressure control by the first valve 51 becomes ineffective, the opening of the second valve 52 is automatically changed. Therefore, as described above, the non-adjustable area S2 is eliminated, and the area is wide. Pressure control can be stably performed within the range.

  Therefore, for example, even when the process conditions are changed on the user side of the apparatus, the initial opening degree of the second valve 52 is automatically changed to an appropriate opening degree according to the conditions. Good pressure control can be performed. In addition, since stable pressure control can be performed, for example, the discharge state can be stabilized in the processing container 10, and the vacuum processing can be performed in a stable state. Thereby, the stability of the product is improved, so that an improvement in yield can be expected.

  As described above, the initial opening degree of the second valve 52 is determined by performing an evaluation test in advance, and when the processing is performed on a substrate different from the product in the processing container 10 and the product In some cases, the discharge state changes when the substrate is processed. For this reason, even if the opening of the second valve 52 is set to an appropriate position in the preliminary evaluation, it is not possible to automatically adjust the opening of the second valve 52 during the process as in the present invention. It is valid.

  Further, in an etching process of a metal film or the like, if there is no more etching species on the substrate S, the pressure in the processing chamber 10 may change rapidly. If the pressure adjustment mechanism cannot cope with this pressure change, the impedance of the plasma changes at a stretch, causing a phenomenon in which a current flows through the wiring of the substrate S and damages it. Conventionally, it was not possible to cope with a sudden change in pressure in the processing vessel 10, and furthermore, it was difficult to control the pressure in a region where the pressure could not be adjusted.

  On the other hand, in the present invention, the opening degree of the first valve 51 changes quickly in response to the pressure change in the processing container 10, and the opening degree of the second valve 52 also changes. It is possible to stabilize the pressure in the processing container 10 in a short time and to perform the conventional pressure adjustment in a region where pressure cannot be adjusted. This is because the opening degree of the first valve 51 having good responsiveness changes first due to the pressure change in the processing container 10, and the opening degree of the second valve 52 changes following this opening degree change. As described above, the plasma can be stabilized in a short time even when the pressure in the processing container 10 changes suddenly, so that the production of the substrate S can be performed stably and the reduction in the yield can be suppressed. In addition, there is an advantage that constraints on the process hardly occur.

  In the above-described embodiment, the opening degree of the second valve 52 is changed in two stages such as “fully closed” → “half open” or “fully closed” → “half open”. Is large, the opening degree of the second valve 52 is changed in three stages such as “fully closed” → “half open” → “fully open” or “full open” → “half open” → “fully closed”. Is also good. In this case, for example, as the threshold value on the side on which the first valve 51 is throttled, a threshold value for changing the second valve 52 from “fully closed” to “half open” and a second valve 52 from “half open” The memory 64 stores two thresholds, that is, a threshold for “full opening”. Further, for example, as the threshold value on the side where the first valve 51 is opened, a threshold value when the second valve 52 is changed from “fully open” to “half open”, and the second valve 52 is changed from “half open” to “fully closed” Are stored in the memory 64.

  Then, based on the detected value of the opening degree of the first valve 51, when the corresponding threshold value is exceeded, the opening degrees of all the second valves 52 are changed from “fully closed” → “half open” → “full open” or , "Fully open" → "Half open" → "Fully closed". Also in this case, since the opening of the second valve 52 is appropriately changed to an appropriate position based on the detected value of the opening of the first valve 51, stable pressure control can be performed in a wide pressure range. it can.

  Furthermore, in the above-described embodiment, the initial opening of the second valve 52 is “fully closed” or “fully open”. However, the initial opening is “half open” and the threshold of the first valve 51 is When it exceeds, the opening degree may be changed to “fully closed” or “fully opened”. In this case, for example, as the threshold value on the side that throttles the first valve 51, the threshold value when the second valve 52 is changed from “half open” to “fully open” and the threshold value on the side that opens the first valve 51 are used. , The threshold value for changing the second valve 52 from “half open” to “fully closed” is stored in the memory 64. Then, if the opening degrees of the first valves 51 exceed the threshold value on the throttle side, the opening degrees of all the second valves 52 are changed from “half open” to “full open”. On the other hand, if the opening degrees of the first valves 51 exceed the threshold value on the opening side, the opening degrees of all the second valves 52 are changed from “half open” to “fully closed”. Also in this case, since the opening of the second valve 52 is appropriately changed based on the detected value of the opening of the first valve 51, stable pressure control can be performed in a wide pressure range.

  Further, the responsiveness of the first valve 51 may be reduced by adjusting the gain of the first valve 51 in accordance with the change in the opening of the second valve 52. By changing the opening of the second valve 52, the opening of the first valve 51 is also changed to the side to be squeezed or opened, but for example, from the change of the opening of the second valve 52, the preset time is equal to the second time. By reducing the responsiveness of the first valve 51, a sudden change in the opening degree of the first valve 51 can be suppressed. For this reason, it is possible to suppress a sudden pressure fluctuation in the processing container 10 and perform more stable pressure control.

  Further, the initial opening of the second valve 52 may be changed based on the transition data of the position of the second valve 52. For example, while processing a large number of substrates S using the same recipe, the opening of the second valve 52 is monitored and acquired as transition data. If the change in the opening of the second valve 52 occurs at an early timing, the initial opening of the second valve 52 is changed from the initially set “full open” or “fully closed” to “ The setting may be changed to “half open”.

  In this case, the initial opening degree of the second valve 52 may be reset by the operator, or the operator may rewrite the recipe. Further, the recipe may be automatically rewritten. For example, in the case of performing automatically, the transition data of the second valve 52 is acquired by the control unit 6, and it is determined whether or not the opening degree of the second valve 52 is changed at a predetermined timing, If it has been changed, a program for changing and rewriting the initial opening of the second valve 52 described in the recipe is stored. Then, for example, for the substrate S of the next lot of the same recipe, the processing is performed by setting the initial opening of the second valve 52 to the rewritten position.

  Further, the predetermined opening degree of the second valve 52 may be at least three, and may be four or more. For example, four opening degrees are set: a first opening degree ("fully closed"), a second opening degree, a third opening degree larger than the second opening degree, and a fourth opening degree ("fully opened"). In this case, two levels of threshold values for the first valve 51 are prepared, and two levels of threshold values for the open side are prepared.

  When the initial opening degree of the second valve 52 is set to the first opening degree (“fully closed”), the opening degree of the first valve 51 exceeds the threshold value on the first throttle side. , The second valve 52 is set to the second opening, and when the opening of the first valve 51 exceeds the second throttle-side threshold, the second valve 52 is set to the third opening. Control to set. On the other hand, when the initial opening degree of the second valve 52 is set to the fourth opening degree ("full open"), when the opening degree of the first valve 51 exceeds the threshold value on the first opening side, The second valve 52 is set to the third opening, and when the opening of the first valve 51 exceeds the second opening threshold, the second valve 52 is set to the second opening. To control.

  In the above, in the present invention, for example, the second valve 52 is stored in advance in the memory 64 in association with the combination of the pressure set value of the pressure at the time of performing the vacuum processing and the flow rate set value of the gas supplied into the processing container. Is stored in advance. On the other hand, the process recipe describes a combination of the pressure set value and the gas flow rate set value. Then, by selecting a process recipe, the initial opening of the corresponding second valve 52 may be read from the memory 64 and the initial position of the second valve 52 may be set.

  Furthermore, the initial opening degree of the second valve 52 may be set based only on the pressure set value of the pressure when performing the vacuum processing. In this case, the pressure set value and the initial opening of the second valve 52 may be described in the process recipe, and the second valve 52 may be set to the initial position by selecting the process recipe. In addition, the pressure set value is described in the process recipe, and the pressure set value and the initial opening degree of the second valve 52 are stored in the memory 64 in association with each other. The second valve 52 may be read out and set to the initial position.

  Furthermore, the threshold value of the first valve 51 and the opening degree of the second valve 52 can be appropriately changed. For example, the transition data of the opening degree of the first valve 51 and the second valve 52 and the transition data of the pressure change in the processing container 10 are acquired, and a more appropriate threshold value and the opening degree of the second valve 52 are obtained. You may set it again. For example, the opening degree of the second valve 52 is changed, for example, when the opening degree of the “fully open” state is set to about “200” when the current state is “300”, or when the opening degree of the “fully closed” state is When the value is about "10" when the value is "1", the opening degree of "half open" is set to about "100" when the current value is "150".

  In the above, in the present invention, a valve whose opening is fixed at several places is used as a semi-fixed valve, but the valve is set to an opening selected from at least three predetermined degrees of opening according to the present invention. The semi-fixed valve is not limited to the case where the opening itself is selected, but also includes a valve that switches the exhaust conductance to a plurality of values. Further, the numbers of the first exhaust path and the second exhaust path are not limited to the above example, and even if each of the first exhaust path and each of the second exhaust paths are connected to a dedicated exhaust mechanism. Good. Further, the vacuum processing apparatus of the present invention can be applied not only to etching processing but also to processing for performing other vacuum processing such as ashing and CVD. Further, the vacuum processing is not necessarily limited to the plasma processing, and may be another gas processing or a vacuum processing other than the gas processing. Furthermore, the object to be processed may be a semiconductor substrate other than the FPD substrate.

S substrate 1 etching processing apparatus 10 processing container 2 mounting table 3 gas supply unit (upper electrode)
41 first exhaust path 42 second exhaust path 51 first valve (automatic adjustment valve)
52 Second valve (semi-fixed valve)
6 control unit

Claims (8)

A processing container in which vacuum processing is performed on the object to be processed,
A first exhaust path and a second exhaust path each having one end connected to the processing container,
A pressure detector for detecting the pressure in the processing container,
An automatic adjustment valve that is provided in the first exhaust path and that automatically adjusts the conductance of the exhaust path based on a pressure detection value and a pressure set value of the pressure detection unit;
A semi-fixed valve provided in the second exhaust path and set to an opening selected from at least three predetermined openings;
An opening detection unit that detects the opening of the automatic adjustment valve,
When the opening detection value detected by the opening detection unit exceeds a predetermined threshold as a pressure adjustment limit, the opening of the semi-fixed valve is increased in order to extend a pressure adjustment range. And a control unit that outputs a control signal so as to change the opening degree to another opening degree.   2. The threshold value according to claim 1, wherein the threshold value is set as a threshold value on a side that reduces the opening degree of the automatic adjustment valve or a threshold value on an opening side according to a selected opening degree of the semi-fixed valve. Vacuum processing equipment.   The initial opening degree of the semi-fixed valve is determined according to a combination of a pressure set value of a pressure at the time of performing vacuum processing and a flow rate set value of a gas supplied into the processing container. 3. The vacuum processing apparatus according to 1 or 2.   For the semi-fixed valve, at least three predetermined opening degrees include a maximum opening degree, a minimum opening degree, and an opening degree between the maximum opening degree and the minimum opening degree of the valve. The vacuum processing apparatus according to claim 1.   The vacuum processing apparatus according to any one of claims 1 to 4, wherein the semi-fixed valve is a valve whose opening can be freely adjusted by a control signal. In a method for performing vacuum processing on an object to be processed in a processing vessel to which a first exhaust path and a second exhaust path are connected,
A step of loading the object to be processed into the processing container;
The semi-fixed valve provided in the second exhaust path and set to an opening selected from at least three predetermined openings is provided with a pressure set value for performing vacuum processing and a processing container. Setting the opening determined according to the combination with the flow rate set value of the gas supplied into,
Thereafter, a step of performing vacuum processing while automatically adjusting an opening degree by an automatic adjustment valve provided in the first exhaust path so that a pressure detection value in the processing container becomes a pressure set value,
Detecting the opening of the automatic adjustment valve,
When the opening detection value detected in the step exceeds a predetermined threshold as a pressure adjustment limit, the opening of the semi-fixed valve, in order to expand the pressure adjustment range, the predetermined opening of the predetermined opening And a step of changing to another opening degree in the vacuum processing method.   For the semi-fixed valve, at least three predetermined opening degrees include a maximum opening degree, a minimum opening degree, and an opening degree between the maximum opening degree and the minimum opening degree of the valve. The vacuum processing method according to claim 6. A storage medium storing software used for an apparatus that performs vacuum processing on a processing target in a processing container to which a first exhaust path and a second exhaust path are connected,
A storage medium, characterized in that the software includes a computer program in which steps are set to execute the vacuum processing method according to claim 6.

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