Substrate processing apparatus capable of adjusting inner pressure of process chamber thereof and method therefor

Described herein is a technique capable of adjusting an inner pressure of a process chamber into a high vacuum state in a short time. According to one aspect of the technique, there is provided a substrate processing apparatus including: a process chamber; a main exhaust line including a first pipe, a first opening degree adjusting valve, an opening/closing valve and a pressure sensor; a bypass exhaust line including a second pipe and a second opening degree adjusting valve; and a controller configured to adjust an inner pressure of the process chamber by: (a) adjusting an opening degree of the second opening degree adjusting valve; (b) closing the second opening degree adjusting valve and opening the opening/closing valve and the first opening degree adjusting valve; and (c) closing the opening/closing valve and the first opening degree adjusting valve and adjusting the opening degree of the second opening degree adjusting valve.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This non-provisional U.S. patent application claims priority under 35 U.S.C. § 119 of Japanese Patent Application No. 2019-144877, filed on Aug. 6, 2019, and Japanese Patent Application No. 2020-117977, filed on Jul. 8, 2020, the entire contents of which are hereby incorporated by reference.

BACKGROUND

The present disclosure relates to a substrate processing apparatus and a non-transitory computer-readable recording medium.

2. Related Art

In manufacturing processes of a semiconductor device, a substrate processing apparatus of a vertical type may be used as an apparatus of performing a substrate processing on a semiconductor substrate (hereinafter, also simply referred to as a “substrate”) serving as an object to be processed including the semiconductor. In particular, according to some related arts, in a substrate processing apparatus configured to perform the substrate processing under a reduced pressure, a main exhaust line is provided across an exhauster such as a pump, an opening/closing valve and an APC (Automatic Pressure Control) valve are provided at the main exhaust line, a bypass exhaust line including an opening/closing valve and bypassing the opening/closing valve of the main exhaust line is provided, and the APC valve is provided on both the main exhaust line and the bypass exhaust line.

According to some related arts described above, by providing the APC valve at the bypass exhaust line, it is possible to gradually reduce an inner pressure of a reaction chamber from atmospheric pressure to a predetermined pressure so that particles (for example, quartz) in the reaction chamber are prevented from diffusing due to a pressure difference between the reaction chamber and a turbo molecular pump serving as the exhauster.

However, since a diameter of a pipe of the bypass exhaust line described above is considerably smaller than a diameter of a pipe of the main exhaust line described above, it may take time to reduce the inner pressure of the reaction chamber from the atmospheric pressure to the predetermined pressure. On the other hand, recently, as the substrate processing, a film-forming process in which a process chamber (that is, the reaction chamber) is in a higher vacuum state as compared with a conventional process may be performed.

SUMMARY

Described herein is a technique capable of bring an inner pressure of a process chamber into a high vacuum state in a short time without diffusing particles in the process chamber.

According to one aspect of the technique of the present disclosure, there is provided a substrate processing apparatus including: a process chamber in which a substrate is processed; a main exhaust line including: a first pipe configured to discharge the gas from the process chamber; a first opening degree adjusting valve provided at the first pipe; an opening/closing valve provided at the first pipe; and a pressure sensor provided at the first pipe and configured to detect an inner pressure of the process chamber; a bypass exhaust line including: a second pipe connected to the main exhaust line; and a second opening degree adjusting valve provided at the second pipe; and a controller configured to adjust the inner pressure of the process chamber to a process pressure by performing: (a) reducing the inner pressure of the process chamber to a first pressure by adjusting an opening degree of the second opening degree adjusting valve based on information from the pressure sensor; (b) reducing the inner pressure of the process chamber to a second pressure by closing the second opening degree adjusting valve and opening the opening/closing valve and the first opening degree adjusting valve when the inner pressure of the process chamber reaches the first pressure; and (c) adjusting the inner pressure of the process chamber to the process pressure by closing the opening/closing valve and the first opening degree adjusting valve and adjusting the opening degree of the second opening degree adjusting valve when the inner pressure of the process chamber reaches the second pressure.

DETAILED DESCRIPTION

Hereinafter, one or more embodiments (also simply referred to as “embodiments”) according to the technique of the present disclosure will be described with reference to the drawings. In the drawings, the same or equivalent constituents are designated by the same reference numerals. In addition, dimensional ratios in the drawings may be exaggerated for convenience of explanation, and may differ from the actual ratios. An upper direction of each drawing will be referred to as “upper” or “upper portion”, and a lower direction of each drawing will be referred to as “lower” or “lower portion” in the following description. Further, each pressure described in the present embodiments may refer to a gas pressure.

<Overall Configuration of Substrate Processing Apparatus>

As shown inFIG.1, a substrate processing apparatus100according to the present embodiments includes: a reaction furnace (which is a process furnace)10including a process chamber20in which a substrate30is processed; a spare chamber22including a boat26configured to transfer the substrate30to the process chamber20; a gas introduction line (which is a gas introduction system)40configured to introduce a gas into the process chamber20; an exhaust system50configured to discharge (exhaust) the gas in the process chamber20from the process chamber; and a main controller70configured to control operations of the substrate processing apparatus100.

As shown inFIG.1, the process chamber20including a reaction tube12and a furnace opening flange14is provided in the reaction furnace10. The reaction tube12is of a cylindrical shape, and an axis of the reaction tube12is provided in the vertical direction. The furnace opening flange14is of a cylindrical shape. The furnace opening flange14is connected to a lower portion of the reaction tube12via an airtight seal12A interposed therebetween, and an axis of the furnace opening flange14is provided in the vertical direction. An inner tube16is supported in the reaction tube12of the reaction furnace10so as to be concentric with the reaction tube12. A heater18is provided on an outer circumference of the reaction tube12so as to be concentric with the axis of the reaction tube12and spaced apart from an outer surface of the reaction tube12. The heater18is configured to receive a signal from the main controller70described later to generate heat, and to heat the reaction tube12. Thus, the reaction furnace10is constituted by the reaction tube12, the furnace opening flange14, the inner tube16, the heater18and the process chamber20. The substrate30may be accommodated in the process chamber20.

As shown inFIG.1, the spare chamber22includes a transfer housing24airtightly communicating with a lower portion of the furnace opening flange14. The boat26is provided in the transfer housing24so as to be vertically movable. The boat26accommodating the substrate30may be transported and inserted (that is, loaded) into the process chamber20. A second gas introduction line (which is a second gas introduction system)44of the same configuration as the gas introduction line40described later in detail may be connected to a lower portion of the transfer housing24such that the gas introduced into the process chamber20may be introduced through the second gas introduction line44. In addition, a furnace opening lid28configured to airtightly close the transfer housing24is provided below the boat26and the transfer housing24.

As shown inFIG.1, the gas introduction line40includes: a gas supplier (which is a gas supply system, not shown); a gas introduction pipe40A connecting the gas supplier and the furnace opening flange14; and a flow rate controller42provided at the gas introduction pipe40A between the gas supplier and the furnace opening flange14. The flow rate controller42is configured to control an amount of the gas introduced by the gas introduction line40(also referred to as a “gas introduction amount”) by opening and closing a valve (not shown) provided in the flow rate controller42in accordance with a signal from the main controller70described later. The second gas introduction line44is of the same configuration as the gas introduction line40except that the gas supplier of the second gas introduction line44and the lower portion of the transfer housing24communicate with each other. The second gas introduction line44is provided as a backup of the gas introduction line40. For example, the gas used in the present embodiments includes an inert gas, and specifically, a nitrogen gas.

The main controller70is configured to control the overall operation of the substrate processing apparatus100. The main controller70may be embodied by a computer that includes components such as a CPU (central processing unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a storage device, an input device, a display and a communication interface, which are not shown in the drawings. Each component of the computer described above is connected to a bus of the computer. Based on information inputted from the input device, the main controller70executes a substrate processing program configured to perform various processes in the substrate processing apparatus100. For example, the main controller70executes a process recipe (which is one of substrate processing programs) to control a substrate processing (which is a part of manufacturing processes of a semiconductor device). When controlling the substrate processing, the main controller70is configured to control an opening/closing operation of a gate valve56of the exhaust system50. In addition, in cooperation with an APC controller72described later, the main controller70is configured to control an inner pressure of the process chamber20by adjusting opening degrees of a first APC valve58A and a second APC valve58B described later. According to the present embodiments, the main controller70is an example of a controller, and the APC controller72described later is an example of the controller. That is, the controller may be constituted by the main controller70and the APC controller72. Hereinafter, the description “the APC valve is closed” means that the opening degree of the APC valve is 0%, and the description “the APC valve is open” means that the opening degree of the APC valve is 100%.

As shown inFIGS.1through3, the exhaust system50includes a main exhaust line (which is a main exhaust system)52and a bypass exhaust line (which is a bypass exhaust system)54. The main exhaust line52includes: a large-diameter pipe52A serving as a first pipe configured to discharge the gas from the process chamber20; the first APC valve58A and the gate valve56provided at the pipe52A; and a pressure sensor group62provided at the pipe52A and configured to detect the inner pressure of the process chamber20. The bypass exhaust line54at least includes: a pipe54A connected to the pipe52A and serving as a second pipe; and the second APC valve58B provided at the pipe54A. When a diameter of the pipe52A is represented by “D”, a diameter of the pipe54A is equal to “D×(0.5 to 0.9)”. That is, the diameter of the pipe54A is less than that of the pipe52A. According to the present embodiments, the gate valve56is an example of an opening/closing valve, the first APC valve58A is an example of a first opening degree adjusting valve, and the second APC valve58B is an example of a second opening degree adjusting valve. One end of the main exhaust line52serving as a stream end opposite to the process chamber20is connected to a suction side of a pump60. The exhaust system50may further include the pump60.

The exhaust system50is controlled by the APC controller72controlling the first APC valve58A and the second APC valve58B and the main controller70.

As shown inFIG.1, the pipe52A, via which the process chamber20communicates with the pump60, and the first APC valve58A and the gate valve56disposed between the process chamber20and the pump60are provided at the main exhaust line52. The gate valve56is electrically connected to the main controller70. The gate valve56is opened or closed (that is, the opening/closing operation of the gate valve56is performed) based on a signal from the main controller70electrically connected to the pressure sensor group62described later. The first APC valve58A is electrically connected to the APC controller72, and an opening/closing operation and an opening degree adjusting operation of the first APC valve58A are performed based on a signal from the APC controller72electrically connected to the pressure sensor group62described later. The main exhaust line52is configured to exhaust the gas in the process chamber20from the process chamber20by a suction operation of the pump60when the first APC valve58A and the gate valve56are open. According to the present embodiments, for example, the diameter of the pipe52A is 200 mm (200 Φ).

As shown inFIG.1, the pipe54A, via which a branch portion54B communicates with a confluence portion54C, and the second APC valve58B disposed at the pipe54A between the branch portion54B and the confluence portion54C are provided at the bypass exhaust line54. The branch portion54B where the pipe54A is branched off from the pipe52A is provided at the pipe52A between the process chamber20and the gate valve56. The confluence portion54C where the pipe54A joins the pipe52A again is provided at the pipe52A between the gate valve56and the pump60. The second APC valve58B is electrically connected to the APC controller72, and an opening/closing operation of the second APC valve58B is performed while adjusting the opening degree of the second APC valve58B based on an operation signal (which is an operation command) from the APC controller72. The APC controller72is configured to receive pressure information of the process chamber20from the main controller70electrically connected to the pressure sensor group62described later, and configured to generate the operation signal. The bypass exhaust line54is configured to exhaust the gas in the process chamber20by the suction operation of the pump60when the gate valve56is closed. The diameter of the pipe54A is 40 mm or more and 180 mm or less, preferably, 80 mm or more and 140 mm or less, and more preferably, 80 mm or more and 100 mm or less (80Φ or more and 100Φ or less). According to the present embodiments, for example, the diameter of the pipe54A is 100 mm (100Φ). As long as the diameter of the pipe54A of the bypass exhaust line54is smaller than the diameter of the pipe52A of the main exhaust line52, the diameter of the pipe54A may be greater than 180 mm. However, when the diameter of the pipe54A is too large, there is no need to provide the bypass exhaust line54. In addition, when the diameter of the pipe54A is greater than 140 mm, particles may be generated during the exhaust process from the atmospheric pressure described later, despite the adjustment of the APC valve such as the second APC valve58B. On the other hand, when the diameter of the pipe54A is too small, an exhaust capacity of an exhaust line such as the bypass exhaust line54may adversely affect the substrate processing. For example, when the diameter of the pipe54A is 40 mm or less, the exhaust capacity may adversely affect the substrate processing.

As shown inFIG.1, the pressure sensor group62is provided so as to communicate with each other by a plurality of pipes62A. The plurality of the pipes62A are connected to the pipe52A at a portion adjacent to the branch portion54B of the pipe52A and between the process chamber20and the branch portion54B. The pressure sensor group62is electrically connected to the main controller70, and is configured to transmit the pressure information of the process chamber20. As described later, the pressure sensor group62is constituted by an atmospheric pressure sensor64, a first vacuum sensor68and a second vacuum sensor66, which are described later. As shown inFIG.2, the first vacuum sensor68, the second vacuum sensor66and the atmospheric pressure sensor64are sequentially provided in this order at the plurality of the pipes62A connected to the pipe52A, respectively. The plurality of the pipes62A are connected to the pipe52A sequentially away from the branch portion54B toward the process chamber20. According to the present embodiments, each of the atmospheric pressure sensor64, the first vacuum sensor68and the second vacuum sensor66is an example of a pressure sensor.

As shown inFIG.2, the atmospheric pressure sensor64is provided at one of the pipes62A closest to the process chamber20among the plurality of the pipes62A connected to the pipe52A, and is configured to detect a pressure within a range close to the atmospheric pressure.

As shown inFIG.2, the first vacuum sensor68is provided at one of the pipes62A, and serves as a wide-range pressure sensor capable of detecting a pressure ranging from a pressure level close to the atmospheric pressure to a predetermined vacuum level (10−1Pa to 105Pa). According to the present embodiments, for example, the first vacuum sensor68is configured to detect the pressure within a range from the atmospheric pressure to a second pressure P2 (for example, 10 Torr).

As shown inFIG.2, the second vacuum sensor66is provided at the pipe62A. The second vacuum sensor66is provided with a valve66A. The valve66A is opened when the pressure is reduced to a predetermined pressure. According to the present embodiments, for example, the valve66A is configured to be opened when the pressure is at the second pressure P2. The second vacuum sensor66serves as a pressure sensor capable of detecting the pressure in a high vacuum range (high vacuum state). According to the present embodiments, for example, the valve66A is opened at the second pressure P2 (for example, 10 Torr) so that the second vacuum sensor66can detect the pressure.

As described above, each of the atmospheric pressure sensor64, the first vacuum sensor68and the second vacuum sensor66is electrically connected to the main controller70.

As shown inFIGS.1and2, the APC controller72is provided at the pipe52A of the main exhaust line52between the gate valve56and the pipe62A or between the gate valve56and the branch portion54B. The APC controller72is electrically connected to the main controller70and the APC controller72. As described above, the APC controller72is configured to receive the pressure information of the process chamber20from the main controller70, and is configured to adjust the opening degrees of the first APC valve58A and the second APC valve58B. As described above, according to the present embodiments, the APC controller72is an example of the controller.

Hereinafter, operations and procedures of the substrate processing apparatus, a method of manufacturing the semiconductor device and the substrate processing program (or a non-transitory computer-readable recording medium) by the exhaust system50will be described with reference toFIGS.3through6.

According to the present embodiments, for example, the exhaust system50is configured to reduce the inner pressure of the process chamber20by adjusting the opening degree of the second APC valve58B by the main controller and the APC controller72based on the information from the pressure sensor group62such that the inner pressure of the process chamber20reaches the first pressure P1. When the inner pressure of the process chamber20reaches the first pressure P1, the exhaust system50is configured to reduce the inner pressure of the process chamber20by closing the second APC valve58B and opening the first APC valve58A and the gate valve56such that the inner pressure of the process chamber20reaches the second pressure P2. When the inner pressure of the process chamber20reaches the second pressure P2, the exhaust system50is configured to reduce the inner pressure of the process chamber20by closing the first APC valve58A and the gate valve56and adjusting the opening degree of the second APC valve58B such that the inner pressure of the process chamber20is reduced to a predetermined high vacuum state. According to the present embodiments, the pressure lower than the second pressure P2 is referred to as the “high vacuum state”. In addition, the exhaust system50is configured to reduce the inner pressure of the process chamber20to the pressure lower than the second pressure P2 in the high vacuum range and to maintain a process pressure of processing the substrate30.

A vertical axis shown inFIG.5represents the inner pressure of the process chamber20, and a horizontal axis shown inFIG.5represents a pressure reduction time (i.e., an amount of time taken to complete pressure reduction). A pressure reduction line “A” according to the present embodiments is illustrated by a thick line inFIG.5, and a pressure reduction line “B” according to a comparative example is illustrated by a thin line inFIG.5. The atmospheric pressure P0 is about 1.023×105Pa (about 760 Torr), the first pressure P1 is about 9.066×104Pa (about 680 Torr), and the second pressure P2 is about 1.333×103Pa (about 10 Torr). When reducing the inner pressure of the process chamber20from the atmospheric pressure, a slow exhaust is performed first. However, the slow exhaust actually takes a few seconds, which is negligible compared with the time of about 5 minutes to 10 minutes which would be taken for pressure change from the atmospheric pressure P0 to the second pressure P2. Therefore, in the present specification, the illustration of the slow exhaust is omitted inFIG.5, and a description of the slow exhaust will be omitted below.

<Pressure Reduction from Atmospheric Pressure to First Pressure>

First, a step of reducing the inner pressure of the process chamber20from the atmospheric pressure P0 to the first pressure P1 at a predetermined rate is performed.

First, a plurality of substrates including the substrate30accommodated in the boat26are transferred and inserted into the process chamber20using the boat26. When the plurality of the substrates are inserted into the process chamber20using the boat26, the inner pressure of the process chamber20is set to the atmospheric pressure (Step S01). In the step S01, the first APC valve58A, the gate valve56(also indicated by a reference numeral “561”) and the second APC valve58B (also indicated by a reference numeral “581”) are closed.

As shown inFIGS.3and6, the pump60is operated first. Subsequently, the first APC valve58A and the gate valve56provided at the pipe52A of the main exhaust line52are closed in response to a closing signal (which is a closing command) from the main controller70. InFIG.3, in order to facilitate the understanding, the gate valve561is additionally illustrated to indicate a closed state of the gate valve56. In addition, the second APC valve58B provided at the pipe54A of the bypass exhaust line54is opened gradually from a closed state toward an open state by adjusting the opening degree of the second APC valve58B in accordance with an opening signal (which is an opening command) from the APC controller72. InFIG.3, in order to facilitate the understanding, the APC valve581is additionally illustrated to indicate a state of the APC valve58B shifting from the closed state toward the open state while its opening degree being adjusted (Step S02).

Then, the inner pressure of the process chamber20is reduced from the atmospheric pressure P0 toward the first pressure P1 while adjusting the opening degree of the second APC valve58B (Step S03). According to the present embodiments, for example, since the diameter of the pipe54A is 0.5 times to 0.9 times the diameter of the pipe52A, the gas in the process chamber20is efficiently exhausted from the process chamber20as compared with the comparative example in which a thin pipe less than 0.5 times the diameter of the pipe52A is used as the pipe54A. In other words, the time (that is, the pressure reduction time) for reducing the inner pressure of the process chamber20from the atmospheric pressure P0 to the first pressure P1 is shortened (refer to the pressure reduction lines “A” and “B” inFIG.5).

<Pressure Reduction from First Pressure to Second Pressure>

Subsequently, a step of reducing the inner pressure of the process chamber20from the first pressure P1 to the second pressure P2 is performed.

Before the inner pressure of the process chamber20is reduced from the first pressure P1 to the second pressure P2, the atmospheric pressure sensor64is turned off, the valve66A of the second vacuum sensor66remains closed, and the first vacuum sensor68detects whether the inner pressure of the process chamber20is reduced to the first pressure P1 (Step S04). Information whether or not the inner pressure of the process chamber20is reduced to the first pressure P1 is transmitted to the main controller70, and in turn, is transmitted from the main controller70to the APC controller72.

As shown inFIG.4, when the inner pressure of the process chamber20is reduced to the first pressure P1, the first APC valve58A and the gate valve56(561) are opened in response to the opening signal from the main controller70. Simultaneously, the second APC valve58B (581) is closed in response to the closing signal from the APC controller72(Step S05).

Then, the inner pressure of the process chamber20is reduced from the first pressure P1 toward the second pressure P2 (Step S06).

<Pressure Reduction from Second Pressure to High Vacuum Range>

Subsequently, a step of further reducing the inner pressure of the process chamber20from the second pressure P2 to the high vacuum range (also referred to as a “step of adjusting the inner pressure of the process chamber20from the second pressure P2 to the process pressure”) is performed.

Before the inner pressure of the process chamber20is reduced from the second pressure P2 to the high vacuum range, the atmospheric pressure sensor64and the first vacuum sensor68are turned off, the valve66A is opened when the inner pressure of the process chamber20reaches the second pressure P2, and the second vacuum sensor66is turned on to detect whether the inner pressure of the process chamber20is reduced to the second pressure P2 (Step S07). Information whether or not the inner pressure of the process chamber20is reduced to the second pressure P2 or not is transmitted to the main controller70, and in turn, is transmitted from the main controller70to the APC controller72.

As shown inFIG.3, when the inner pressure of the process chamber20is reduced to the second pressure P2, the first APC valve58A and the gate valve56(561) are closed in response to the closing signal from the main controller70. Simultaneously, the second APC valve58B (581) is opened by the opening signal from the APC controller72while adjusting the opening degree of the second APC valve58B (581) (Step S08).

Then, the inner pressure of the process chamber20is maintained at a predetermined process pressure from the second pressure P2 (Step S09). For example, the process pressure is a pressure at which a film-forming temperature is reached in a film-forming step described later. According to the present embodiments, as described later, the process pressure may not be in the high vacuum state and, may be higher than the second pressure P2. For example, after the inner pressure of the process chamber20is further reduced from the second pressure P2 to the high vacuum range, the inner pressure of the process chamber20may be adjusted again to the process pressure. In addition, after a leakage of the process chamber20is checked when the inner pressure of the process chamber20is reduced to the ultimate vacuum pressure, the inner pressure of the process chamber20may be adjusted again to the process pressure. In such a case, it is preferable that a purge gas such as the inert gas is supplied when adjusting the inner pressure of the process chamber20from the ultimate vacuum pressure to the process pressure.

Then, while the inner pressure of the process chamber20is maintained at the predetermined process pressure, the substrate30is processed (Step S10).

Subsequently, it is detected whether or not the substrate processing of the substrate30is completed (Step S10). When information that the substrate processing is completed is transmitted to the main controller70after the substrate processing is completed, the main controller70is operated such that the inert gas (for example, nitrogen gas) is supplied into the process chamber20and an inner atmosphere of the process chamber20is replaced by a nitrogen atmosphere (Step S11). Subsequently, the first APC valve58A, the gate valve56and the second APC valve58B are closed in accordance with the closing signal from the main controller70and the APC controller72such that the inner pressure of the process chamber20is increased. Thereby, the inner pressure of the process chamber20is returned to the atmospheric pressure. When the inner pressure of the process chamber20reaches a certain pressure (for example, an arbitrary pressure equal to or less than the atmospheric pressure), the main controller70may transmit an instruction for a desired pressure (for example, the atmospheric pressure) to the APC controller72, and the APC controller72receiving the instruction may transmit the opening signal to the second APC valve58B to open the second APC valve58B. When opening the second APC valve58B, it is preferable to control the second APC valve58B (581) such that the inner pressure of the process chamber20reaches the atmospheric pressure while adjusting the opening degree of the second APC valve58B, as described above with reference toFIG.3(Step S12).

Then, the processed substrates including the substrate30are discharged (unloaded) out of the process chamber20.

InFIG.5, a time duration between time points t and t′ and a time duration between time points 5t and 5t′, in which the inner pressure of the process chamber20is not reduced, indicate the amounts of time taken for switching the first APC valve58A, the second APC valve58B and the gate valve56. However, the time durations illustrated inFIG.5are exaggerated to facilitate the understanding of switching the first APC valve58A, the second APC valve58B and the gate valve56, and the actual time durations for switching the first APC valve58A, the second APC valve58B and the gate valve56are very short.

InFIG.5, a pressure reduction time of reducing the inner pressure of the process chamber20according to the comparative example is shown as the pressure reduction line “B”. A diameter of a pipe and a flow rate of an APC valve of a bypass exhaust line according to the comparative example are smaller than the diameter of the pipe54A and a flow rate of the second APC valve58B of the bypass exhaust line54according to present embodiments, respectively. Specifically, the diameter of the pipe of the bypass exhaust line according to the comparative example is 0.2 times the diameter of a main exhaust line according to the comparative example. Therefore, in the pressure reduction line “B”, the pressure reduction time of reducing the inner pressure of the process chamber20from the atmospheric pressure P0 to the first pressure P1 is about 5t, and the pressure reduction time of reducing the inner pressure of the process chamber20from the atmospheric pressure P0 to the second pressure P2 is about 10t.

On the other hand, according to the present embodiments, as described above, the diameter of the pipe54A of the bypass exhaust line54is 0.5 times to 0.9 times the diameter D of the pipe52A of the main exhaust line52. Therefore, according to the present embodiments, as shown by the pressure reduction line “A” inFIG.5, the pressure reduction time of reducing the inner pressure of the process chamber20from the atmospheric pressure P0 to the first pressure P1 is about t, and the pressure reduction time of reducing the inner pressure of the process chamber20from the atmospheric pressure P0 to the second pressure P2 is about 5t. In a pressure range of the high vacuum range below the second pressure P2, it is extremely difficult to further reduce the inner pressure of the process chamber20according to the comparative example as shown by the pressure reduction line “B”. However, according to the present embodiments, since a pressure reduction efficiency of the bypass exhaust line54is higher than that of the bypass exhaust line according to the comparative example, it is possible to further reduce the inner pressure of the process chamber20into the high vacuum range. Therefore, it is possible to perform the substrate processing (for example, a film-forming process) in a high vacuum state.

As described above, according to the present embodiments, when the inner pressure of the process chamber20is reduced to the predetermined vacuum state, the main controller70adjusts the opening degree of the second APC valve58B of the bypass exhaust line54to reduce the inner pressure of the process chamber20to the first pressure P1.

Here, since the diameter of the pipe54A of the bypass exhaust line54is 0.4 times to 0.9 times the diameter of the pipe52A of the main exhaust line52, an exhaust amount according to the present embodiments is not smaller than an exhaust amount according to the comparative example. Therefore, it is possible to shorten the pressure reduction time of reducing the inner pressure of the process chamber20to the first pressure P1 as compared with a substrate processing apparatus according to the comparative example. In addition, since the opening degree of the second APC valve58B is adjusted to reduce the inner pressure of the process chamber20, it is possible to suppress the diffusion of the particles in the process chamber20as compared with a case where the gate valve56and the first APC valve58A of the main exhaust line52are opened to perform an initial exhaust.

When the inner pressure of the process chamber20is reduced to the first pressure P1, by closing the second APC valve58B and opening the gate valve56and the first APC valve58A, the gas in the process chamber20is exhausted through the main exhaust line52including the pipe52A. Thereby the exhaust amount per unit time is increased, and the pressure reduction time of reducing the inner pressure of the process chamber20to the second pressure P2 can be shortened. That is, since the pressure reduction time of reducing the inner pressure of the process chamber20to the high vacuum state can be shortened, the present embodiments can be applied to the substrate processing performed in a high vacuum state, which is recently more in use.

When the inner pressure of the process chamber20is reduced to the second pressure P2, the gate valve56and the first APC valve58A are closed, the second APC valve58B is opened, and the inner pressure of the process chamber20is further reduced into the high vacuum range of a higher vacuum degree. Since a responsiveness of the second APC valve58B is higher than that of the gate valve56or that of the first APC valve58A, and the diameter of the pipe54A of the bypass exhaust line54is smaller than the diameter of the pipe52A of the main exhaust line52, it is possible to achieve the high vacuum state without an air leakage.

Hereinafter, a substrate processing method including a predetermined process, which is performed by using the substrate processing apparatus100according to the present embodiments, will be described. For example, the predetermined process will be described by way of an example in which the substrate processing serving as a part of manufacturing processes of the semiconductor device is performed as the predetermined process.

When performing the substrate processing, the process recipe is loaded in a component such as a memory (not shown). Then, the main controller70transmits a control instruction to the APC controller72and transmits an operation instruction to a process system controller (not shown) or a transfer system controller (not shown). The substrate processing performed as described above includes at least a loading step, a film-forming step and an unloading step.

The main controller70controls a substrate transfer device (which is a substrate transfer mechanism, not shown) to start a transfer process of transferring (loading) the substrate30to the boat26. The transfer process is performed until the substrates scheduled to be loaded into the boat26including the substrate30are completely loaded into the boat26(wafer charging).

When a predetermined number of the substrates (that is, the plurality of the substrates including the substrate30) are loaded into the boat26, the boat26is elevated by the boat elevator (not shown), and is loaded into the process chamber20provided in the reaction furnace10(boat loading). When the boat26is completely loaded into the process chamber20, the furnace opening lid28airtightly closes the lower end of the furnace opening flange14of the reaction furnace10.

Thereafter, the inner atmosphere of the process chamber20is vacuum-exhausted by a vacuum exhaust device (not shown) such as a vacuum pump (not shown) in accordance with an instruction from the APC controller72such that the inner pressure of the process chamber20reaches the predetermined process pressure (vacuum degree). In addition, the process chamber20is heated by the heater18in accordance with an instruction from a temperature controller (not shown) such that an inner temperature of the process chamber20reaches a predetermined process temperature. Subsequently, the boat26and the plurality of the substrates including the substrate30accommodated in the boat26are rotated by a rotator (which is a rotating mechanism, not shown). While the inner pressure of the process chamber20is maintained at the predetermined process pressure and the inner temperature of the process chamber20is maintained at the predetermined process temperature, a predetermined gas such as a process gas is supplied to the plurality of the substrates including the substrate30accommodated in the boat26in order to perform the predetermined process (for example, the film-forming process) to the substrate30. The inner temperature of the process chamber20may be lowered from the process temperature (that is, the predetermined process temperature) before the performing the unloading step.

After the film-forming step to the substrate30accommodated in the boat26is completed, the rotator stops the rotation of the boat26and the plurality of the substrates including the substrate30accommodated in the boat26. Then, the inner atmosphere of the process chamber20is replaced by the nitrogen atmosphere (nitrogen substitution step), and the inner pressure of the process chamber20is returned to the atmospheric pressure. The furnace opening lid28is lowered in order to open the lower end of the furnace opening flange14. The boat26with the processed substrates including the substrate30accommodated therein are then transferred (unloaded) out of the reaction furnace10(boat unloading).

Thereafter, the boat26with the processed substrates including the substrate30accommodated therein is very effectively cooled by clean air ejected from a clean air supplier (which is a clean air supply mechanism, not shown). For example, when the boat26is cooled to 150° C. or lower, the processed substrates including the substrate30are transferred (discharged) from the boat26(wafer discharging) to a pod (not shown). When a batch processing is continuously performed, other unprocessed substrates may be transferred to the boat26.

As described above, according to the present embodiments, the inner atmosphere of process chamber20is vacuum-exhausted in at least one among the step of reducing the inner pressure of the process chamber20from the atmospheric pressure P0 to the first pressure P1, the step of reducing the inner pressure of the process chamber20from the first pressure P1 to the second pressure P2 and the step of adjusting the inner pressure of the process chamber20from the second pressure P2 to the process pressure. In addition, the purge gas may be supplied in at least one among the steps described above while the inner atmosphere of process chamber20is vacuum-exhausted.

As described above, according to the present embodiments, two vacuum sensors (that is, the first vacuum sensor68and the second vacuum sensor66) are used to detect the inner pressure of the process chamber20in the step of reducing the inner pressure of the process chamber20from the atmospheric pressure P0 to the first pressure P1, the step of reducing the inner pressure of the process chamber20from the first pressure P1 to the second pressure P2 and the step of adjusting the inner pressure of the process chamber20from the second pressure P2 to the process pressure. However, a vacuum sensor “A” may be used to detect the inner pressure of the process chamber20in the step of reducing the inner pressure of the process chamber20from the atmospheric pressure P0 to the first pressure P1, a vacuum sensor “B” may be used to detect the inner pressure of the process chamber20in the step of reducing the inner pressure of the process chamber20from the first pressure P1 to the second pressure P2, and a vacuum sensor “C” may be used to detect the inner pressure of the process chamber20in the step of adjusting the inner pressure of the process chamber20from the second pressure P2 to the process pressure in a high vacuum state.

As described above, according to the present embodiments, since the inner pressure of the process chamber20is reduced from the pressure near the atmospheric pressure to a certain negative pressure (for example, the first pressure) while adjusting the opening degree of the APC valve, it is possible to adjust the inner pressure of the process chamber20into a high vacuum state in a short time without diffusing the particles in the process chamber20.

While the embodiments of the technique described above is mainly described by way of an example in which the process pressure is lower than the second pressure P2, the technique is not limited thereto. The process pressure may be higher than the second pressure P2. Hereinafter, other embodiments where the process pressure is higher than the second pressure P2 will be described. Since the step of reducing the inner pressure of the process chamber20from the atmospheric pressure to the first pressure P1 according to the other embodiments is the same as described above, and a description thereof will be omitted. According to the other embodiments, when the inner pressure of the process chamber20reaches the first pressure P1, the inner atmosphere of the process chamber20is exhausted to reduce the inner pressure of the process chamber20through the pipe52A of the main exhaust line52by closing the second APC valve58B and opening the gate valve56while adjusting the opening degree of the first APC valve58A such that the inner pressure of the process chamber20reaches the process pressure.

Alternatively, when the inner pressure of the process chamber20is reduced to a certain pressure by opening the first APC valve58A according to the process pressure, the opening degree of the first APC valve58A may be adjusted such that the inner pressure of the process chamber20reaches the process pressure. The certain pressure reduced by opening the first APC valve58A may be higher or lower than the process pressure because it may be reduced to a pressure near the process pressure.

Even in the other embodiments, since the inner pressure of the process chamber20is reduced from the pressure near the atmospheric pressure to the certain negative pressure (for example, the first pressure) while adjusting the opening degree of the APC valve, it is possible to adjust the inner pressure of the process chamber into the process pressure in a short time without diffusing the particles in the process chamber.

According to some embodiments in the present disclosure, it is possible to adjust the inner pressure of the process chamber into a high vacuum state in a short time without diffusing the particles in the process chamber.