A semiconductor process furnace and a method for controlling oxygen and pressure in a loading and unloading chamber thereof

Abstract

The present application discloses a method for controlling oxygen and pressure of a semiconductor process furnace and its loading and unloading chamber. When oxygen control of the loading and unloading chamber begins, the control valve is opened at a preset first angle, and the gas flow regulator is controlled to deliver oxygen-control gas to the loading and unloading chamber at a preset first gas flow rate; the oxygen content in the loading and unloading chamber detected by the detection device and the pressure value therein are obtained; after the oxygen content reaches the preset target oxygen content, the oxygen content reaches the target oxygen content, and the pressure value is within the preset positive pressure safety range as the adjustment target, and the gas flow delivered by the gas flow regulator and the opening angle of the valve are adjusted to meet the adjustment target. It can be seen that the present application can control the oxygen content in the loading and unloading chamber so that the oxygen content meets the process requirements; at the same time, the pressure value in the loading and unloading chamber can be controlled so that the loading and unloading chamber maintains a slight positive pressure, and the slight positive pressure can effectively prevent external air from entering the loading and unloading chamber, thereby ensuring the oxygen content control effect and improving the processing quality.

Description

Technical Field

[0001] The present application relates to the field of vertical furnace processing, and in particular to an oxygen and pressure control method for a semiconductor process furnace and a loading and unloading chamber thereof. Background Art

[0002] The vertical furnace series equipment includes a process chamber and a loading and unloading chamber (LA), such as Figure 1 As shown, the loading and unloading chamber is below the process chamber, the loading and unloading chamber is used for loading and unloading silicon wafers, and the process chamber is used for processing silicon wafers. Specifically, when preparing to process silicon wafers, the silicon wafers to be processed are placed in the boat for placing silicon wafers in the loading and unloading chamber, and the boat is fixed on a lifting carrier for lifting the boat. After the silicon wafers are placed, the boat is raised to the process chamber by the lifting carrier, and the transfer port between the process chamber and the loading and unloading chamber is sealed, and then the silicon wafers are processed in the process chamber. After the silicon wafers are processed, the boat is lowered into the loading and unloading chamber by the lifting carrier, and then the processed silicon wafers are unloaded from the boat, thus completing the entire processing flow of these silicon wafers.

[0003] However, during the processing of silicon wafers, the temperature is generally very high, resulting in the surface temperature of the silicon wafer still being very high when it drops to the loading and unloading chamber after processing. At this time, if the oxygen content in the loading and unloading chamber is high, the oxygen molecules in the loading and unloading chamber will chemically react with the silicon wafer, resulting in the formation of an unnecessary oxide layer on the silicon wafer, thereby reducing the processing quality of the silicon wafer. Summary of the invention

[0004] The purpose of the present application is to provide an oxygen and pressure control method for a semiconductor process furnace and a loading and unloading chamber thereof, which can control the oxygen content in the loading and unloading chamber so that the oxygen content meets the process requirements; at the same time, the pressure value in the loading and unloading chamber can be controlled to keep the loading and unloading chamber at a slightly positive pressure. The slightly positive pressure can effectively prevent outside air from entering the loading and unloading chamber, thereby ensuring the oxygen content control effect and improving the processing quality.

[0005] In order to solve the above technical problems, the present application provides an oxygen and pressure control method for a loading and unloading chamber of a semiconductor process furnace, which is applied to an oxygen and pressure control device; the oxygen and pressure control device comprises: a detection device for detecting the oxygen content and the pressure value in the loading and unloading chamber, a gas flow regulator provided on an air inlet pipe of the loading and unloading chamber for controlling the air inlet flow of the air inlet pipe, and a valve provided on an exhaust pipe of the loading and unloading chamber for controlling the exhaust volume of the exhaust pipe; the oxygen and pressure control method comprises:

[0006] When oxygen control of the loading and unloading chamber begins, the valve is controlled to open at a preset first angle, and the gas flow regulator is controlled to deliver oxygen-controlling gas into the loading and unloading chamber at a preset first gas flow rate;

[0007] Obtaining the oxygen content and the pressure value in the loading and unloading chamber detected by the detection device;

[0008] After the oxygen content reaches the preset target oxygen content, the gas flow delivered by the gas flow regulator and the opening angle of the valve are adjusted to meet the adjustment target, with the oxygen content reaching the preset target oxygen content and the pressure value being within a preset positive pressure safety range.

[0009] Optionally, the exhaust pipe includes: a main exhaust pipe and an auxiliary exhaust pipe; the valve includes: a main valve provided on the main exhaust pipe for controlling the opening and closing of the main exhaust pipe, and an auxiliary valve provided on the auxiliary exhaust pipe for controlling the exhaust volume of the auxiliary exhaust pipe;

[0010] Then, when the oxygen control of the loading and unloading chamber begins, the valve is controlled to open at a preset first angle, including:

[0011] When oxygen control of the loading and unloading chamber begins, based on the correspondence between the preset oxygen content setting value and the preset valve angle, a target valve preset angle corresponding to the preset target oxygen content is determined, and the main valve is controlled to open the main exhaust pipe, and the auxiliary valve is controlled to open at the target valve preset angle;

[0012] After the oxygen content reaches the preset target oxygen content, the gas flow rate delivered by the gas flow regulator and the opening angle of the valve are adjusted to meet the adjustment target when the oxygen content reaches the preset target oxygen content and the pressure value is within the preset positive pressure safety range, including:

[0013] After the oxygen content reaches the preset target oxygen content, the main valve is controlled to close the main exhaust pipe, and the gas flow delivered by the gas flow regulator and the opening angle of the auxiliary valve are adjusted to meet the adjustment target when the oxygen content reaches the preset target oxygen content and the pressure value is within the preset positive pressure safety range.

[0014] Optionally, taking the oxygen content reaching the preset target oxygen content and the pressure value being within a preset positive pressure safety range as the adjustment target, adjusting the gas flow delivered by the gas flow regulator and the opening angle of the auxiliary valve to meet the adjustment target includes:

[0015] Based on the correspondence between the preset oxygen content setting value and the gas flow rate, determining a target gas flow rate corresponding to the preset target oxygen content, and adjusting the gas flow rate delivered by the gas flow rate regulator to the target gas flow rate;

[0016] After the gas flow delivered by the gas flow regulator is adjusted to the target gas flow, the opening angle of the auxiliary valve is controlled based on a preset valve control strategy to control the oxygen content at the preset target oxygen content and the pressure value within a preset positive pressure safety range.

[0017] Optionally, adjusting the gas flow delivered by the gas flow regulator to the target gas flow includes:

[0018] directly adjusting the gas flow delivered by the gas flow regulator from the first gas flow to a preset second gas flow; wherein the first gas flow>the second gas flow>the target gas flow;

[0019] At every preset flow rate adjustment cycle, determining whether the gas flow rate currently delivered by the gas flow rate regulator is greater than the target gas flow rate;

[0020] If so, based on Y last =Y now -t 1 *R 1 Calculate the flow rate Y to be adjusted corresponding to the gas flow regulator last , and adjust the gas flow rate currently delivered by the gas flow regulator to the flow rate to be adjusted; wherein, Y now is the gas flow rate currently delivered by the gas flow regulator; t 1 is the flow regulation period; R 1 Adjust the step rate for a preset flow rate;

[0021] If not, the gas flow rate currently delivered by the gas flow regulator is maintained at the target gas flow rate.

[0022] Optionally, controlling the opening angle of the auxiliary valve based on a preset valve control strategy to control the oxygen content at the preset target oxygen content and the pressure value within a preset positive pressure safety range includes:

[0023] The pressure value is fuzzified to obtain a first fuzzy value, and the oxygen content difference between the oxygen content and the preset target oxygen content is fuzzified to obtain a second fuzzy value;

[0024] Inferring the first fuzzy quantity and the second fuzzy quantity according to a preset control rule to obtain an inference result, and clarifying the inference result to obtain an angle deviation value;

[0025] The angle deviation value is added to the current opening angle of the auxiliary valve to obtain the angle to be opened of the auxiliary valve, and the current opening angle of the auxiliary valve is adjusted to the angle to be opened, so as to control the oxygen content difference to be less than the preset error threshold and control the pressure value within the preset positive pressure safety range.

[0026] Optionally, the fuzzy processing of the pressure value to obtain a first fuzzy value, and the fuzzy processing of the oxygen content difference between the oxygen content and the preset target oxygen content to obtain a second fuzzy value include:

[0027] According to y 1 =(P-(a 1 +b 1 ) / 2)*k 1 Calculate the fuzzy mapping value y corresponding to the pressure value P 1 ; Among them, a 1 is the lower limit of the physical domain of the pressure value; b 1 k is the upper limit of the physical domain of the pressure value; 1 The quantization factor of the pressure value, k 1 =2*n 1 / (b 1 -a 1 );n 1 is the upper limit of the fuzzy domain of the pressure value;

[0028] From the fuzzy subset of the fuzzy domain of the pressure value, determine the fuzzy mapping value y 1 a corresponding first fuzzy quantity, and determining the membership degree of the first fuzzy quantity according to the membership function of the first fuzzy quantity;

[0029] According to y 2 =(e-(a 2 +b 2 ) / 2)*k 2 Calculate the fuzzy mapping value y corresponding to the oxygen content difference e 2 ; Among them, a 2 is the lower limit of the physical range of the oxygen content difference; b 2 k is the upper limit of the physical range of the oxygen content difference; 2 The quantification factor of the oxygen content difference, k 2 =2*n 2 / (b 2 -a 2 );n 2 is the upper limit of the fuzzy domain of the oxygen content difference;

[0030] From the fuzzy subset of the fuzzy domain of the oxygen content difference, determine the fuzzy mapping value y 2A corresponding second fuzzy quantity is obtained, and a membership degree of the second fuzzy quantity is determined according to a membership function of the second fuzzy quantity.

[0031] Optionally, the inference of the first fuzzy quantity and the second fuzzy quantity according to a preset control rule to obtain an inference result, and clarification processing of the inference result to obtain an angle deviation value includes:

[0032] determining whether the first fuzzy quantity and the second fuzzy quantity are within a fuzzy control range or a flow rate increment control range;

[0033] If it is within the fuzzy control range, a first fuzzy inference amount corresponding to the first fuzzy amount and the second fuzzy amount is determined according to the preset corresponding relationship between the fuzzy amount of the pressure value, the fuzzy amount of the oxygen content difference and the fuzzy inference amount, and the minimum degree of membership between the first fuzzy amount and the second fuzzy amount is used as the degree of membership of the first fuzzy inference amount, so as to clarify the first fuzzy inference amount and obtain the angle deviation value;

[0034] If it is within the flow rate increasing control range, the inference result is determined to be flow rate increasing control, and the inference result is clarified to obtain an angle deviation value of 0, and the gas flow rate delivered by the gas flow regulator is controlled to increase until the first fuzzy quantity and the second fuzzy quantity enter the fuzzy control range.

[0035] Optionally, the clarifying the first fuzzy inference amount to obtain the angle deviation value includes:

[0036] If there are multiple first fuzzy inference quantities, selecting a target fuzzy inference quantity with the largest membership degree from the first fuzzy inference quantities;

[0037] Determining a target fuzzy subset corresponding to the target fuzzy inference amount from the fuzzy subsets of the fuzzy domain of the angle deviation value;

[0038] Based on the fact that multiple relational expressions in the membership function of the target fuzzy subset are all equal to the membership degree of the target fuzzy inference quantity, multiple equations are established, and the solution results of the multiple equations are averaged to obtain an average value;

[0039] According to ΔU=k u ×m+(c+d) / 2 to calculate the angle deviation value ΔU; where k u is the proportional factor of the angle deviation value, k u =(d-c) / (2*n 3 );n 3is the upper limit of the fuzzy domain of the angle deviation value; m is the average value; c is the lower limit of the physical domain of the angle deviation value; d is the upper limit of the physical domain of the angle deviation value.

[0040] Optionally, the corresponding relationship between the oxygen content setting value and the preset valve angle, and the corresponding relationship between the oxygen content setting value and the gas flow rate, include:

[0041] When the loading and unloading chamber is subjected to parameter self-tuning, the main valve is controlled to open the main exhaust pipe, the auxiliary valve is controlled to open at a preset second angle, and the gas flow regulator is controlled to deliver the oxygen-controlling gas into the loading and unloading chamber at a preset second gas flow rate;

[0042] Acquiring the current oxygen content and the current pressure value in the loading and unloading chamber detected by the detection device;

[0043] After the current oxygen content reaches the oxygen content setting value, controlling the main valve to close the main exhaust pipe, and performing PID regulation on the gas flow delivered by the gas flow regulator based on the current error between the current oxygen content and the oxygen content setting value;

[0044] After the current oxygen content reaches the oxygen content set value again, the opening angle of the auxiliary valve is adjusted with the current pressure value within the preset positive pressure safety range as the angle adjustment target, and the gas flow delivered by the gas flow regulator is continuously PID-regulated;

[0045] When the current oxygen content reaches the oxygen content setting value and the current pressure value is within the preset positive pressure safety range, the gas flow currently delivered by the gas flow regulator is used as the gas flow corresponding to the oxygen content setting value, and the current opening angle of the auxiliary valve is used as the valve preset angle corresponding to the oxygen content setting value.

[0046] Optionally, adjusting the opening angle of the auxiliary valve by taking the current pressure value within a preset positive pressure safety range as an angle adjustment target includes:

[0047] At every preset angle adjustment cycle, it is determined whether the current pressure value is within a preset positive pressure safety range;

[0048] If the current pressure value is greater than the maximum value of the preset positive pressure safety range, then based on V last =V now +V i Calculate the opening angle V of the auxiliary valve last and adjust the current opening angle of the auxiliary valve to the angle to be opened V last ; Among them, V nowis the current opening angle of the auxiliary valve; V i Adjust the angle for units;

[0049] If the current pressure value is less than the minimum value of the preset positive pressure safety range, then based on V last =V now -V i Calculate the opening angle V of the auxiliary valve last and adjust the current opening angle of the auxiliary valve to the angle to be opened V last ;

[0050] If the current pressure value is within the preset positive pressure safety range, the current opening angle of the auxiliary valve is maintained.

[0051] In order to solve the above technical problems, the present application also provides a semiconductor process furnace, including: a control device, a loading and unloading chamber, and an oxygen and pressure control device, wherein:

[0052] The oxygen and pressure control equipment comprises:

[0053] A detection device for detecting the oxygen content and the pressure value in the loading and unloading chamber;

[0054] A gas flow regulator provided on the air intake pipe of the loading and unloading chamber for controlling the air intake flow of the air intake pipe;

[0055] A valve provided on the exhaust pipe of the loading and unloading chamber for controlling the exhaust volume of the exhaust pipe;

[0056] The control device is connected to the detection device, the gas flow regulator and the valve respectively, and is used to execute any of the above-mentioned oxygen and pressure control methods for loading and unloading chambers of semiconductor process furnaces.

[0057] The present application provides an oxygen and pressure control method for a loading and unloading chamber of a semiconductor process furnace, which is applied to an oxygen and pressure control device; the oxygen and pressure control device comprises: a detection device for detecting the oxygen content in the loading and unloading chamber and the pressure value therein, a gas flow regulator arranged on the air inlet pipe of the loading and unloading chamber for controlling the air intake flow of the air inlet pipe, and a valve arranged on the exhaust pipe of the loading and unloading chamber for controlling the exhaust volume of the exhaust pipe; the oxygen and pressure control method comprises: when oxygen control of the loading and unloading chamber starts, the valve is controlled to open at a preset first angle, and the gas flow regulator is controlled to deliver oxygen-controlling gas to the loading and unloading chamber at a preset first gas flow rate; the oxygen content in the loading and unloading chamber and the pressure value therein detected by the detection device are obtained; after the oxygen content reaches a preset target oxygen content, the gas flow delivered by the gas flow regulator and the opening angle of the valve are adjusted to meet the adjustment target, with the oxygen content reaching the target oxygen content and the pressure value being within a preset positive pressure safety range as the adjustment target. It can be seen that the present application can control the oxygen content in the loading and unloading chamber so that the oxygen content meets the process requirements; at the same time, the pressure value in the loading and unloading chamber can be controlled to keep the loading and unloading chamber at a slightly positive pressure. The slightly positive pressure can effectively prevent outside air from entering the loading and unloading chamber, thereby ensuring the oxygen content control effect and improving the processing quality.

[0058] The present application also provides a semiconductor process furnace, which has the same beneficial effects as the above-mentioned oxygen and pressure control method. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0060] Figure 1 It is a structural schematic diagram of a vertical furnace series equipment in the prior art;

[0061] Figure 2 A schematic diagram of a scenario of an oxygen and pressure control method for a semiconductor process furnace loading and unloading chamber provided in an embodiment of the present application;

[0062] Figure 3 A flow chart of a method for controlling oxygen and pressure in a loading and unloading chamber of a semiconductor process furnace provided in an embodiment of the present application;

[0063] Figure 4 A schematic diagram of a specific scenario of an oxygen and pressure control method for a semiconductor process furnace loading and unloading chamber provided in an embodiment of the present application;

[0064] Figure 5A membership function diagram of a fuzzy subset of a pressure value, an oxygen content difference value or an angle deviation value provided in an embodiment of the present application;

[0065] Figure 6 A control effect diagram of an oxygen and pressure control method for a semiconductor process furnace loading and unloading chamber provided in an embodiment of the present application;

[0066] Figure 7 A framework diagram of a dual-input dual-output control system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0067] The core of the present application is to provide an oxygen and pressure control method for a semiconductor process furnace and its loading and unloading chamber, which can control the oxygen content in the loading and unloading chamber so that the oxygen content meets the process requirements; at the same time, the pressure value in the loading and unloading chamber can be controlled to keep the loading and unloading chamber at a slightly positive pressure. The slightly positive pressure can effectively prevent outside air from entering the loading and unloading chamber, thereby ensuring the oxygen content control effect and improving the processing quality.

[0068] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0069] Please refer to Figure 2 , Figure 2 A schematic diagram of a method for controlling oxygen and pressure in a semiconductor process furnace loading and unloading chamber provided in an embodiment of the present application. Figure 2As shown, the scene includes: a process chamber, a loading and unloading chamber, a blower, a filter, a heat exchanger, an air backfill valve, an exhaust pipe (LA exhaust), an air inlet pipe (air inlet), and oxygen and pressure control equipment; the oxygen and pressure control equipment includes: a detection device (not shown in the figure), a gas flow regulator (such as MFC (Mass flow Controller, gas mass flow controller)), a valve and a control device arranged on the exhaust pipe of the loading and unloading chamber. The loading and unloading chamber is installed below the process chamber; the blower is installed at the lower right side of the loading and unloading chamber to provide circulating air. The blower keeps working after the machine is powered on to ensure that the air is circulated all the time; the filter is installed on the right side of the loading and unloading chamber to purify the circulating air and ensure the particle size; the heat exchanger is installed on the left side of the loading and unloading chamber to reduce the temperature of the circulating air; the air backfill valve is installed at the upper right side of the loading and unloading chamber to control the entry of external air into the loading and unloading chamber; the exhaust pipe is installed at the top of the loading and unloading chamber to discharge the gas in the loading and unloading chamber body; the detection device is used to detect the oxygen content f in the loading and unloading chamber and the pressure value P therein; the air inlet pipe is installed on the right side of the door of the loading and unloading chamber, and the gas flow regulator is arranged on the air inlet pipe, and the gas flow regulator delivers the oxygen control gas to the loading and unloading chamber through the set gas flow; the valve is arranged on the exhaust pipe of the loading and unloading chamber, and is used to control the exhaust volume of the exhaust pipe; the control device is respectively connected with the detection device, the gas flow regulator and the valve, and is used to adjust the gas flow delivered by the gas flow regulator and the opening angle of the valve to control the oxygen and pressure of the loading and unloading chamber. It should be noted that when the loading and unloading chamber is not oxygen controlled, the air backfill valve is opened, the gas flow regulator has no gas flow output, the valve is opened at a certain angle, and the oxygen content of the entire loading and unloading chamber is consistent with the surrounding environment of the equipment. After the loading and unloading chamber is oxygen controlled, the air backfill valve is closed to maintain the low oxygen and slightly positive pressure state of the loading and unloading chamber by adjusting the gas flow delivered by the gas flow regulator and the opening angle of the valve.

[0070] Based on the above application scenario architecture, the present application embodiment provides a method for controlling oxygen and pressure in a loading and unloading chamber. Figure 3 , Figure 3 This is a flow chart of a method for controlling oxygen and pressure in a loading and unloading chamber provided in an embodiment of the present application. Figure 3 The method in can be Figure 2 The control device in the implementation, such as Figure 3 As shown, the method comprises the following steps:

[0071] Step S101: When oxygen control of the loading and unloading chamber begins, the valve is controlled to open at a preset first angle, and the gas flow regulator is controlled to deliver oxygen-controlling gas into the loading and unloading chamber at a preset first gas flow rate.

[0072] In the embodiment of the present application, when oxygen control of the loading and unloading chamber begins, an oxygen-controlling gas is delivered to the loading and unloading chamber, and the oxygen-controlling gas does not chemically react with the processing object in a preset processing temperature range. For example, if the processing object is a silicon wafer, and the processing temperature of the silicon wafer is in the range of 700°C-900°C, the oxygen-controlling gas can be selected from nitrogen (N2), which does not chemically react with the silicon wafer in the range of 700°C-900°C and is cheap. 2 ), the purpose of doing this is: by delivering oxygen-controlled gas to the loading and unloading chamber, the loading and unloading chamber is kept in a low-oxygen state. When the processing object descends to the loading and unloading chamber after processing, although the surface temperature of the processing object is still maintained within the preset processing temperature range, the oxygen content in the loading and unloading chamber is very low at this time. The oxygen content in the loading and unloading chamber is basically oxygen-controlled gas that does not chemically react with the processing object within the preset processing temperature range, thereby avoiding the formation of unnecessary oxide layer on the processing object and reducing the processing quality.

[0073] In a specific application, when oxygen control of the loading and unloading chamber begins, the control device controls the valve on the exhaust pipe to open at a preset first angle to discharge the gas in the loading and unloading chamber, and the control device also controls the gas flow regulator to deliver oxygen-controlled gas to the loading and unloading chamber at a preset first gas flow rate (such as the gas flow regulator can select the maximum range output, in this case the first gas flow rate = 1000slm / min, slm / min is the gas flow unit), in order to discharge the oxygen in the loading and unloading chamber so that the loading and unloading chamber is in a low oxygen state.

[0074] Step S102: Obtaining the oxygen content and the pressure value in the loading and unloading chamber detected by the detection device.

[0075] In an embodiment of the present application, the detection device may include a differential pressure gauge and an oxygen analyzer. The differential pressure gauge is used to detect the pressure value in the loading and unloading chamber, and the oxygen analyzer is used to detect the oxygen content in the loading and unloading chamber.

[0076] In a specific application, when oxygen control of the loading and unloading chamber begins, the detection device detects the oxygen content and the pressure value in the loading and unloading chamber in real time, and sends the detected oxygen content and the pressure value in the loading and unloading chamber to the control device for analysis and processing.

[0077] Step S103: After the oxygen content reaches the preset target oxygen content, the oxygen content reaches the preset target oxygen content and the pressure value is within the preset positive pressure safety range as the adjustment target, and the gas flow delivered by the gas flow regulator and the opening angle of the valve are adjusted to meet the adjustment target.

[0078] In a specific application, after receiving the oxygen content in the loading and unloading chamber detected by the detection device, the control device determines whether the oxygen content in the loading and unloading chamber reaches a preset target oxygen content (such as 10ppm, ppm is the unit of oxygen content to meet process requirements). If the preset target oxygen content is not reached, the gas flow rate (first gas flow rate) delivered by the gas flow regulator and the opening angle of the valve (first angle) are maintained; if the preset target oxygen content is reached, oxygen and pressure control operations are performed to put the loading and unloading chamber in a low oxygen and slightly positive pressure state (slightly positive pressure can effectively prevent outside air from entering the loading and unloading chamber, thereby ensuring the oxygen content control effect).

[0079] Specifically, the size of the gas flow delivered by the gas flow regulator and the size of the valve opening angle will affect the oxygen content and pressure value of the loading and unloading chamber. Under the same conditions, the larger the gas flow delivered by the gas flow regulator, the faster the oxygen content in the loading and unloading chamber decreases, and the greater the pressure value of the loading and unloading chamber; the larger the valve opening angle, the smaller the pressure value of the loading and unloading chamber, and the slower the speed at which the oxygen content in the loading and unloading chamber decreases (under the same conditions, the greater the pressure value of the loading and unloading chamber, the faster the oxygen content decreases). Based on this, the control device can perform oxygen and pressure control operations by adjusting the gas flow delivered by the gas flow regulator and the opening angle of the valve. Specifically, the oxygen content in the loading and unloading chamber reaches a preset target oxygen content, and the pressure value in the loading and unloading chamber is within a preset positive pressure safety range (such as 1500-3500mtorr, mtorr is the unit of pressure, to ensure that the loading and unloading chamber operates reliably under a slightly positive pressure state) as the adjustment target, and the gas flow delivered by the gas flow regulator and the opening angle of the valve are adjusted to ensure that the oxygen content in the loading and unloading chamber reaches the preset target oxygen content, and the pressure value in the loading and unloading chamber is within the preset positive pressure safety range.

[0080] The present application provides an oxygen and pressure control method for a loading and unloading chamber of a semiconductor process furnace. When oxygen control of the loading and unloading chamber begins, the valve is controlled to open at a preset first angle, and the gas flow regulator is controlled to deliver oxygen-control gas to the loading and unloading chamber at a preset first gas flow rate; the oxygen content in the loading and unloading chamber and the pressure value therein detected by the detection device are obtained; after the oxygen content reaches the preset target oxygen content, the oxygen content reaches the target oxygen content, and the pressure value is within the preset positive pressure safety range as the adjustment target, and the gas flow delivered by the gas flow regulator and the opening angle of the valve are adjusted to meet the adjustment target. It can be seen that the present application can control the oxygen content in the loading and unloading chamber so that the oxygen content meets the process requirements; at the same time, the pressure value in the loading and unloading chamber can be controlled so that the loading and unloading chamber maintains a slight positive pressure, and the slight positive pressure can effectively prevent external air from entering the loading and unloading chamber, thereby ensuring the oxygen content control effect and improving the processing quality.

[0081] Based on the above embodiments:

[0082] Please refer to Figure 4 , Figure 4 A schematic diagram of a specific scenario of a method for controlling oxygen and pressure in a loading and unloading chamber provided in an embodiment of the present application.

[0083] As an optional embodiment, the exhaust pipe includes: a main exhaust pipe and an auxiliary exhaust pipe; the valve includes: a main valve provided on the main exhaust pipe for controlling the opening and closing of the main exhaust pipe, and an auxiliary valve provided on the auxiliary exhaust pipe for controlling the exhaust volume of the auxiliary exhaust pipe;

[0084] When oxygen control starts in the loading and unloading chamber, the valve is controlled to open at a preset first angle, including:

[0085] When oxygen control starts for the loading and unloading chamber, based on the correspondence between the preset oxygen content setting value and the preset valve angle, the target valve preset angle corresponding to the preset target oxygen content is determined, and the main valve is controlled to open the main exhaust duct, and the auxiliary valve is controlled to open at the target valve preset angle;

[0086] After the oxygen content reaches the preset target oxygen content, the oxygen content reaches the preset target oxygen content and the pressure value is within the preset positive pressure safety range as the adjustment target, and the gas flow rate delivered by the gas flow regulator and the opening angle of the valve are adjusted to meet the adjustment target, including:

[0087] After the oxygen content reaches the preset target oxygen content, the main valve is controlled to close the main exhaust duct, and the oxygen content reaches the preset target oxygen content and the pressure value is within the preset positive pressure safety range as the adjustment target, and the gas flow delivered by the gas flow regulator and the opening angle of the auxiliary valve are adjusted to meet the adjustment target.

[0088] In the embodiment of the present application, the exhaust duct on the loading and unloading chamber includes a main exhaust duct and an auxiliary exhaust duct. The present application does not limit the number of the main exhaust duct and the auxiliary exhaust duct. Figure 4 As shown, the exhaust pipe on the loading and unloading chamber includes a main exhaust pipe and an auxiliary exhaust pipe. Correspondingly, the valves arranged on the exhaust pipe include: a main valve arranged on the main exhaust pipe for controlling the opening and closing of the main exhaust pipe, and an auxiliary valve arranged on the auxiliary exhaust pipe for controlling the exhaust volume of the auxiliary exhaust pipe. The main valve here can be a pneumatic valve, and the auxiliary valve can be a butterfly valve.

[0089] In a specific application, the control device stores in advance the correspondence between the oxygen content set value (the set value of the oxygen content in the loading and unloading chamber that is ultimately to be reached) and the valve preset angle (the initial opening angle of the auxiliary valve when oxygen control begins). When oxygen control of the loading and unloading chamber begins, the control device first determines the valve preset angle (called the target valve preset angle) corresponding to the preset target oxygen content based on the correspondence between the preset oxygen content set value and the valve preset angle, and then controls the main valve to open the main exhaust pipe, and controls the auxiliary valve to open at the target valve preset angle, so that the main exhaust pipe and the auxiliary exhaust pipe are used together to exhaust the gas in the loading and unloading chamber.

[0090] After the oxygen content in the loading and unloading chamber reaches the preset target oxygen content, the control device performs oxygen control and pressure control operations. Specifically, the main valve is first controlled to close the main exhaust duct, leaving only the auxiliary exhaust duct to discharge the gas in the loading and unloading chamber, and then the oxygen content in the loading and unloading chamber reaches the preset target oxygen content, and the pressure value in the loading and unloading chamber is within the preset positive pressure safety range as the adjustment target, and the gas flow rate delivered by the gas flow regulator and the opening angle of the auxiliary valve are adjusted to ensure that the oxygen content in the loading and unloading chamber reaches the preset target oxygen content and the pressure value in the loading and unloading chamber is within the preset positive pressure safety range.

[0091] As an optional embodiment, the oxygen content reaches a preset target oxygen content, and the pressure value is within a preset positive pressure safety range as the adjustment target, and the gas flow rate delivered by the gas flow regulator and the opening angle of the auxiliary valve are adjusted to meet the adjustment target, including:

[0092] Based on the correspondence between the preset oxygen content setting value and the gas flow rate, determining a target gas flow rate corresponding to the preset target oxygen content, and adjusting the gas flow rate delivered by the gas flow regulator to the target gas flow rate;

[0093] After the gas flow delivered by the gas flow regulator is adjusted to the target gas flow, the opening angle of the auxiliary valve is controlled based on the preset valve control strategy to control the oxygen content at the preset target oxygen content and the pressure value within the preset positive pressure safety range.

[0094] In specific applications, the control device stores in advance the correspondence between the oxygen content set value (the oxygen content set value that the loading and unloading chamber is ultimately to reach) and the gas flow rate (the gas flow rate that the gas flow regulator ultimately delivers during oxygen control) .

[0095] Based on this, after the oxygen content in the loading and unloading chamber reaches the preset target oxygen content, the control device performs the oxygen control and pressure control operations as follows: first, adjust the gas flow delivered by the gas flow regulator: based on the corresponding relationship between the preset oxygen content setting value and the gas flow, determine the gas flow corresponding to the preset target oxygen content (called the target gas flow), and adjust the gas flow delivered by the gas flow regulator to the target gas flow; secondly, adjust the opening angle of the auxiliary valve: after the gas flow delivered by the gas flow regulator is adjusted to the target gas flow, control the opening angle of the auxiliary valve based on the preset valve control strategy, so as to ultimately control the oxygen content in the loading and unloading chamber to the preset target oxygen content, and control the pressure value in the loading and unloading chamber to within the preset positive pressure safety range.

[0096] As an optional embodiment, adjusting the gas flow rate delivered by the gas flow regulator to a target gas flow rate includes:

[0097] The gas flow rate delivered by the gas flow regulator is directly adjusted from the first gas flow rate to the preset second gas flow rate; wherein the first gas flow rate> the second gas flow rate> the target gas flow rate;

[0098] At every preset flow rate adjustment cycle, it is determined whether the gas flow rate currently delivered by the gas flow rate regulator is greater than the target gas flow rate;

[0099] If so, based on Y last =Y now -t 1 *R 1 Calculate the flow rate Y to be adjusted corresponding to the gas flow regulator last , and adjust the gas flow rate currently delivered by the gas flow regulator to the flow rate to be adjusted; where Y now is the gas flow rate currently delivered by the gas flow regulator; t 1 is the flow regulation cycle; R 1 Adjust the step rate for a preset flow rate;

[0100] If not, the gas flow rate currently delivered by the gas flow regulator is maintained at the target gas flow rate.

[0101] In a specific application, when the control device adjusts the gas flow delivered by the gas flow regulator, the control device first directly adjusts the gas flow delivered by the gas flow regulator from the first gas flow to the preset second gas flow (e.g., the preset second gas flow = 500slm / min, the second gas flow is the maximum gas flow of the gas flow delivered by the gas flow regulator in the subsequent segmented adjustment process, then the adjustment range of the gas flow delivered by the gas flow regulator in the subsequent segmented adjustment process is: target gas flow Q to 500slm / min), and then every preset flow adjustment cycle, the gas flow Y currently delivered by the gas flow regulator is determined.now Is it greater than the target gas flow rate Q? If it is greater than the target gas flow rate (Y now >Q), then based on Y last =Y now -t 1 *R 1 Calculate the flow rate Y to be adjusted corresponding to the gas flow regulator last and the gas flow rate Y currently delivered by the gas flow regulator now Adjust to the flow rate Y to be adjusted last ; If it is not greater than the target gas flow rate (Y now ≤Q), the gas flow rate currently delivered by the gas flow regulator is maintained at the target gas flow rate Q, that is, the flow rate to be adjusted Y corresponding to the gas flow regulator last =Q, and finally the gas flow delivered by the gas flow regulator is adjusted to the target gas flow Q.

[0102] As an optional embodiment, the opening angle of the auxiliary valve is controlled based on a preset valve control strategy to control the oxygen content within a preset target oxygen content and the pressure value within a preset positive pressure safety range, including:

[0103] The pressure value is fuzzified to obtain a first fuzzy value, and the oxygen content difference between the oxygen content and the target oxygen content is fuzzified to obtain a second fuzzy value;

[0104] Reasoning the first fuzzy quantity and the second fuzzy quantity according to a preset control rule to obtain a reasoning result, and clarifying the reasoning result to obtain an angle deviation value;

[0105] The angle deviation value is added to the current opening angle of the auxiliary valve to obtain the angle to be opened of the auxiliary valve, and the current opening angle of the auxiliary valve is adjusted to the angle to be opened to control the oxygen content difference to be less than the preset error threshold and the pressure value to be controlled within the preset positive pressure safety range.

[0106] In a specific application, the control device controls the opening angle of the auxiliary valve based on the pressure value P in the loading and unloading chamber and the oxygen content difference e between the oxygen content in the loading and unloading chamber and the preset target oxygen content. Specifically, the opening angle of the auxiliary valve is controlled based on the fuzzy control strategy: 1) Fuzzification processing: fuzzify the pressure value P to obtain the first fuzzy quantity M1, and fuzzify the oxygen content difference e to obtain the second fuzzy quantity M2; 2) Control reasoning: reason the first fuzzy quantity M1 and the second fuzzy quantity M2 according to the preset control rules to obtain the reasoning result u; 3) Clarification processing: clarify the reasoning result u to obtain the angle deviation value ΔU; 4) Angle control: add the angle deviation value ΔU to the current opening angle U of the auxiliary valve. now , get the auxiliary valve opening angle Ulast (U last =U now +ΔU), and the current opening angle of the auxiliary valve U now Adjust to the opening angle U last , so as to control the oxygen content difference e to be less than the preset error threshold and the pressure value P to be within the preset positive pressure safety range.

[0107] As an optional embodiment, the pressure value is fuzzified to obtain a first fuzzy value, and the oxygen content difference between the oxygen content and the target oxygen content is fuzzified to obtain a second fuzzy value, including:

[0108] According to y 1 =(P-(a 1 +b 1 ) / 2)*k 1 Calculate the fuzzy mapping value y corresponding to the pressure value P 1 ; Among them, a 1 is the lower limit of the physical domain of pressure value; b 1 k is the upper limit of the physical domain of pressure value; 1 Quantization factor of pressure value, k 1 =2*n 1 / (b 1 -a 1 );n 1 is the upper limit of the fuzzy domain of pressure value;

[0109] From the fuzzy subset of the fuzzy domain of pressure values, determine the fuzzy mapping value y 1 A corresponding first fuzzy quantity, and determining the membership degree of the first fuzzy quantity according to the membership function of the first fuzzy quantity;

[0110] According to y 2 =(e-(a 2 +b 2 ) / 2)*k 2 Calculate the fuzzy mapping value y corresponding to the oxygen content difference e 2 ; Among them, a 2 is the lower limit of the physical range of oxygen content difference; b 2 k is the upper limit of the physical range of oxygen content difference; 2 Quantification factor for oxygen content difference, k 2 =2*n 2 / (b 2 -a 2 );n 2 is the upper limit of the fuzzy domain of oxygen content difference;

[0111] From the fuzzy subset of the fuzzy domain of oxygen content difference, determine the fuzzy mapping value y 2The corresponding second fuzzy quantity is determined, and the membership degree of the second fuzzy quantity is determined according to the membership function of the second fuzzy quantity.

[0112] In the embodiment of the present application, the control parameters of the fuzzy control include: the physical domain, fuzzy domain, and quantization factor of the input variables (pressure value P, oxygen content difference e) required for fuzzy calculation, and the physical domain, fuzzy domain, and proportional factor of the output variable (angle deviation value ΔU).

[0113] Specifically, the fuzzy subsets of the fuzzy domain of the input variable and the output variable can be set to {NB (negative large), NS (negative small), ZO (zero), PS (positive small), PB (positive large)}. Combined with the general design principles, the fuzzy domain of the pressure value P can be defined as {-2, -1, 0, 1, 2}, the fuzzy domain of the oxygen content difference e can be defined as {-2, -1, 0, 1, 2}, and the fuzzy domain of the angle deviation value ΔU can be defined as {-2, -1, 0, 1, 2}. According to the actual situation, the triangular membership function (other membership functions can also be used), the fuzzy subset distribution of the input variable and the output variable is as follows: Figure 5 As shown, the horizontal axis is the value of the pressure value, oxygen content difference or angle deviation value after size transformation, and the vertical axis is the degree of membership.

[0114] Based on a large number of experiments, the ideal pressure range of the loading and unloading chamber is 2.5±1torr (torr is the unit of pressure, 1torr=1000mtorr), so the physical domain of the pressure value P can be defined [P min , P max ] is [1500, 3500], in mtorr; the oxygen content detection value range of the loading and unloading chamber is 0-1000ppm (greater than 1000ppm, all display 1000ppm), the target oxygen content of the process is usually 10ppm or 5ppm, then the physical domain of the oxygen content difference e can be defined as [-10, 10] (values ​​less than -10ppm are all regarded as -10ppm), in ppm; the range of the auxiliary valve is 100% angle. Given the preset valve angle, the adjustable range of the auxiliary valve is ±10% of the range, then the physical domain of the set angle deviation value ΔU is [-10, 10].

[0115] In summary, the fuzzy control parameter correspondence table is shown in Table 1 below:

[0116] Table 1

[0117] Physical Domain Fuzzy domain Quantization Factor Pressure value P [1500,3500] [-2,2] 0.002 Oxygen content difference e [-10，10] [-2,2] 0.2 Fuzzy domain Physical Domain Scale Factor Angle deviation ΔU [-2,2] [-10,10] 5

[0118] The quantization factor of the input variable is calculated by the relationship k=2*n / (ba), where n is the upper limit of the fuzzy domain of the input variable, a is the lower limit of the physical domain of the input variable, and b is the upper limit of the physical domain of the input variable. For the pressure value P, the quantization factor calculation relationship is k 1 =2*n 1 / (b 1 -a 1 ), let n 1 =2, b 1 =3500, a 1 =1500, then the quantization factor of the pressure value P is 0.002. For the oxygen content difference e, the quantization factor calculation formula is k 2 =2*n 2 / (b 2 -a 2 ), let n 2 =2, b 2 =10, a 2 =-10, the quantization factor of the oxygen content difference e is 0.2. The proportional factor of the output variable is expressed by the relation k u =(dc) / (2*n 3 ) calculation, in the relation, n 3 is the upper limit of the fuzzy domain of the output variable; c is the lower limit of the physical domain of the output variable; d is the upper limit of the physical domain of the output variable. For the angle deviation value ΔU, let n 3 =2, d=10, c=-10, then the proportional factor of the angle deviation value ΔU is 5.

[0119] Based on this, during the fuzzy processing, the control device performs the fuzzy processing on the pressure value P, including: first, according to y 1 =(P-(a 1 +b 1 ) / 2)*k 1 Calculate the fuzzy mapping value y corresponding to the pressure value P 1 Then, from the fuzzy subset of the fuzzy domain of the pressure value P, determine the fuzzy mapping value y 1 The corresponding first fuzzy quantity M1 (may correspond to one fuzzy subset or two fuzzy subsets), and the membership degree of the first fuzzy quantity M1 is determined according to the membership function of the first fuzzy quantity M1.

[0120] For example, if the pressure value of the loading and unloading chamber is P = 2800 mtorr, then y 1 =(2800-(1500+3500) / 2)×0.002=0.6; according to Figure 5 Fuzzy subset distribution diagram of medium pressure value, y 1=0.6 corresponds to 0 (fuzzy subset ZO) and 1 (fuzzy subset PS); according to the membership functions of ZO and PS fuzzy subsets:

[0121]

[0122] Taking Xp = 0.6, we get ZO(0.6) = 0.4, PS(0.6) = 0.6, that is, P = 2800mtorr, the mapped fuzzy quantities are 0 and 1, and the corresponding membership degrees are 0.4 and 0.6.

[0123] Similarly, the fuzzy processing of the oxygen content difference e by the control device includes: first, according to y 2 =(e-(a 2 +b 2 ) / 2)*k 2 Calculate the fuzzy mapping value y corresponding to the oxygen content difference e 2 Then, from the fuzzy subset of the fuzzy domain of the oxygen content difference e, determine the fuzzy mapping value y 2 The corresponding second fuzzy quantity M2 is obtained, and the membership degree of the second fuzzy quantity M2 is determined according to the membership function of the second fuzzy quantity M2.

[0124] As an optional embodiment, the first fuzzy quantity and the second fuzzy quantity are inferred according to a preset control rule to obtain an inference result, and the inference result is clarified to obtain an angle deviation value, including:

[0125] Determine whether the first fuzzy quantity and the second fuzzy quantity are within the fuzzy control range or within the flow rate increment control range;

[0126] If it is within the fuzzy control range, the first fuzzy inference amount corresponding to the first fuzzy amount and the second fuzzy amount is determined according to the corresponding relationship between the fuzzy amount of the preset pressure value, the fuzzy amount of the oxygen content difference and the fuzzy inference amount, and the minimum degree of membership between the first fuzzy amount and the second fuzzy amount is used as the degree of membership of the first fuzzy inference amount, so as to clarify the first fuzzy inference amount and obtain the angle deviation value;

[0127] If it is within the flow rate increasing control range, the reasoning result is determined to be flow rate increasing control, and the reasoning result is clarified to obtain an angle deviation value of 0, and the gas flow rate delivered by the gas flow regulator is controlled to increase until the first fuzzy quantity and the second fuzzy quantity enter the fuzzy control range.

[0128] In the embodiment of the present application, the preset control rule can be set according to the actual operation experience of the loading and unloading chamber. For example, if the pressure value P is very small and the oxygen content difference e is too large, the opening angle of the auxiliary valve is reduced. This rule can be described as: If M1 is NB and M2 is PB, then u is NB. Similarly, other rules can be established, as shown in Table 2 below:

[0129] Table 2

[0130]

[0131] Among them, the preset control rules correspond to the fuzzy control range (the corresponding relationship between the fuzzy quantity characterizing the pressure value P, the fuzzy quantity of the oxygen content difference e, and the fuzzy reasoning quantity) and the flow rate increment control range. The places without "_" in the table belong to the fuzzy control range, and the places marked with "_" in the table belong to the flow rate increment control range. The places marked with "_" in the table indicate that the gas flow rate currently delivered by the gas flow regulator is too small, and the gas flow rate delivered by the gas flow regulator needs to be increased. At this time, when it is clarified, the angle deviation value ΔU is directly 0, that is, the angle of the auxiliary valve remains unchanged, and the gas flow rate delivered by the gas flow regulator is adjusted at the same time (when the first fuzzy quantity M1 and the second fuzzy quantity M2 enter the fuzzy control range, stop adjusting the gas flow rate delivered by the gas flow regulator).

[0132] In a specific application, the control device determines whether the first fuzzy quantity M1 and the second fuzzy quantity M2 are within the fuzzy control range or within the flow rate increasing control range during the control reasoning process. If they are within the fuzzy control range, the first fuzzy reasoning quantity u corresponding to the first fuzzy quantity M1 and the second fuzzy quantity M2 is determined according to the corresponding relationship between the fuzzy quantity of the preset pressure value P, the fuzzy quantity of the oxygen content difference e and the fuzzy reasoning quantity, and the smallest degree of membership among the degrees of membership of the first fuzzy quantity M1 and the second fuzzy quantity M2 is used as the degree of membership of the first fuzzy reasoning quantity u, so as to clarify the first fuzzy reasoning quantity u and obtain the angle deviation value ΔU; if it is within the flow rate increasing control range, the reasoning result is determined to be flow rate increasing control, and the reasoning result is clarified to obtain the angle deviation value ΔU of 0, and the gas flow rate delivered by the gas flow regulator is controlled to increase until the first fuzzy quantity M1 and the second fuzzy quantity M2 enter the fuzzy control range.

[0133] For example, the first fuzzy quantity M1=0, and its membership μ1=0.4; the second fuzzy quantity M2=1, and its membership μ2=0.8. Then, according to the control rule table in Table 2, it is determined that the first fuzzy quantity M1 and the second fuzzy quantity M2 are within the fuzzy control range, and the first fuzzy inference quantity u corresponding to the first fuzzy quantity M1 and the second fuzzy quantity M2 is found. The membership μ′ of the first fuzzy inference quantity u takes the smaller value of μ1 and μ2, that is, μ′=0.4.

[0134] More specifically, the control device controls the process of increasing the gas flow rate delivered by the gas flow regulator, including: every preset flow rate increase cycle, based on Y last =Y now +t 2 *R 2 Calculate the flow rate Y to be adjusted corresponding to the gas flow regulator last and the gas flow rate Y currently delivered by the gas flow regulator now Adjust to the flow rate Y to be adjusted last ; where t 2 is the preset flow rate increment cycle (can be preset to 120s); R 2 It is the preset flow rate increment rate (can be preset to 10slm / min).

[0135] It should be noted that when there is more than one first fuzzy amount M1 or second fuzzy amount M2, as long as there is a first fuzzy amount M1 or second fuzzy amount M2 within the fuzzy control range, it is considered that the first fuzzy amount M1 or second fuzzy amount M2 is within the fuzzy control range.

[0136] As an optional embodiment, the first fuzzy inference amount is clarified to obtain an angle deviation value, including:

[0137] If there are multiple first fuzzy inference quantities, then select the target fuzzy inference quantity with the largest membership degree from the first fuzzy inference quantities;

[0138] From the fuzzy subsets of the fuzzy domain of the angle deviation value, a target fuzzy subset corresponding to the target fuzzy reasoning quantity is determined;

[0139] Based on the fact that multiple relational expressions in the membership function of the target fuzzy subset are equal to the membership degree of the target fuzzy inference quantity, multiple equations are established, and the solution results of the multiple equations are averaged to obtain an average value;

[0140] According to ΔU=k u ×m+(c+d) / 2 to calculate the angle deviation value ΔU; where k u is the proportional factor of the angle deviation value, k u =(d-c) / (2*n 3 );n 3 is the upper limit of the fuzzy domain of the angle deviation value; m is the average value; c is the lower limit of the physical domain of the angle deviation value; d is the upper limit of the physical domain of the angle deviation value.

[0141] In specific applications, the control device uses the maximum membership average method to clarify the first fuzzy inference quantity. This method can meet actual control needs, has a small amount of calculation, and the average method has stable output, which solves the problem of frequent adjustments.

[0142] For example, the first fuzzy inference quantity u has two groups (u = 0, μ' = 0.6) and (u = 1, μ' = 0.4), then the fuzzy inference quantity with a large membership degree (u = 0, μ' = 0.6) is selected, and then according to Figure 5 Fuzzy subset distribution diagram of the angle deviation value in the middle, u=0 is the fuzzy subset ZO, according to the membership function of the ZO fuzzy subset:

[0143]

[0144] The equations are: m1+1=0.6 and -m2+1=0.6. Solving these two equations yields: m1=-0.4 and m2=0.4. The average method yields: m=(m1+m2) / 2=(-0.4+0.4) / 2=0. Then according to ΔU=k u ×m+(c+d) / 2 to calculate the angle deviation value ΔU, where the proportional factor k u =5, the physical upper and lower limits of the angle deviation value are d=10 and c=-10, then ΔU=5×0+(10+(-10)) / 2=0.

[0145] Based on the above-mentioned oxygen and pressure control method of the loading and unloading chamber, the following can be obtained: Figure 6 When the equipment is ready to start the processing process, the oxygen content in the loading and unloading chamber needs to be controlled at the target oxygen content. According to the above-mentioned oxygen and pressure control method of the loading and unloading chamber, the oxygen content in the loading and unloading chamber changes as follows: Figure 6 As shown, the left vertical axis represents the oxygen content (unit ppm), the right vertical axis represents the gas flow delivered by the gas flow regulator (unit slm / min), the horizontal axis represents time (unit s), the dotted line represents the change of oxygen content over time, and the solid line represents the change of gas flow delivered by the gas flow regulator. Figure 6 The target oxygen content is 11ppm. After reaching the target oxygen content, the oxygen content in the loading and unloading chamber is maintained at 11±1ppm. Through control and adjustment, the gas flow rate delivered by the gas flow regulator is finally stabilized at 360slm / min (the gas flow rate corresponding to the target oxygen content). After point a, the gas flow rate delivered by the gas flow regulator is controlled in sections and the auxiliary valve is fuzzy controlled.

[0146] As an optional embodiment, the corresponding relationship between the oxygen content setting value and the preset valve angle, and the corresponding relationship between the oxygen content setting value and the gas flow rate, include:

[0147] When the loading and unloading chamber is subjected to parameter self-tuning, the main valve is controlled to open the main exhaust pipe, the auxiliary valve is controlled to open at a preset second angle, and the gas flow regulator is controlled to deliver the oxygen-controlling gas into the loading and unloading chamber at a preset second gas flow rate;

[0148] Obtaining the current oxygen content and the current pressure value in the loading and unloading chamber detected by the detection device;

[0149] After the current oxygen content reaches the oxygen content set value, the main valve is controlled to close the main exhaust pipe, and based on the current error between the current oxygen content and the oxygen content set value, the gas flow delivered by the gas flow regulator is PID regulated;

[0150] After the current oxygen content reaches the oxygen content setting value again, the current pressure value is within the preset positive pressure safety range as the angle adjustment target, the opening angle of the auxiliary valve is adjusted, and the PID adjustment of the gas flow delivered by the gas flow regulator continues;

[0151] When the current oxygen content reaches the oxygen content setting value and the current pressure value is within the preset positive pressure safety range, the gas flow currently delivered by the gas flow regulator is used as the gas flow corresponding to the oxygen content setting value, and the current opening angle of the auxiliary valve is used as the valve preset angle corresponding to the oxygen content setting value.

[0152] In specific applications, the correspondence between the oxygen content setting value, the gas flow rate and the preset valve angle is obtained by performing parameter self-tuning on the loading and unloading chamber in advance. When performing parameter self-tuning on the loading and unloading chamber, the control device controls the main valve to open the main exhaust duct, and controls the auxiliary valve to open at a preset second angle (such as a 50% angle), and controls the gas flow regulator to deliver the oxygen-controlling gas to the loading and unloading chamber at a preset second gas flow rate (such as the gas flow regulator can select a 50% range output, in which case the second gas flow rate = 500slm / min). At the same time, the detection device detects the current oxygen content and the current pressure value in the loading and unloading chamber in real time, and sends the detected current oxygen content and the current pressure value in the loading and unloading chamber to the control device. After receiving the current oxygen content in the loading and unloading chamber detected by the detection device, the control device determines whether the current oxygen content in the loading and unloading chamber reaches the oxygen content setting value S. If the oxygen content setting value S is not reached, the opening state of the main valve, the gas flow rate (second gas flow rate) delivered by the gas flow regulator and the opening angle (second angle) of the auxiliary valve are maintained; if the oxygen content setting value S is reached, the main valve is controlled to close the main exhaust duct, and only the opening angle (second angle) of the auxiliary valve is maintained, and based on the current error between the current oxygen content in the loading and unloading chamber and the oxygen content setting value, the gas flow rate delivered by the gas flow regulator is PID (Proportion Integral Differential) adjusted, so as to reduce the error between the oxygen content in the loading and unloading chamber and the oxygen content setting value. The control device continues to determine whether the current oxygen content in the loading and unloading chamber has reached the oxygen content setting value S. If it has not reached the oxygen content setting value S, the control device continues to perform PID regulation on the gas flow delivered by the gas flow regulator; if it has reached the oxygen content setting value S, the current pressure value in the loading and unloading chamber is taken as the angle adjustment target within the preset positive pressure safety range, the opening angle of the sub-valve is adjusted, and the gas flow delivered by the gas flow regulator continues to be PID regulated. The control device continues to determine whether the current oxygen content in the loading and unloading chamber reaches the oxygen content setting value S, and determines whether the current pressure value in the loading and unloading chamber is within the preset positive pressure safety range. If the current oxygen content in the loading and unloading chamber does not reach the oxygen content setting value, and / or the current pressure value in the loading and unloading chamber is not within the preset positive pressure safety range, the control device continues to adjust the opening angle of the auxiliary valve and the gas flow rate delivered by the gas flow regulator; if the current oxygen content in the loading and unloading chamber reaches the oxygen content setting value, and the current pressure value in the loading and unloading chamber is within the preset positive pressure safety range, the gas flow rate currently delivered by the gas flow regulator is used as the gas flow rate corresponding to the oxygen content setting value S (it can also be calculated according to the relationship Q= <y 10>×10 (<> is a rounding operator, which means that the absolute value of the value is rounded to the nearest integer, and the positive and negative signs are the same as those in <>), the gas flow rate y currently delivered by the gas flow regulator is processed, and then the processed gas flow rate Q is used as the gas flow rate corresponding to the oxygen content setting value S), and the current opening angle of the auxiliary valve is used as the valve preset angle corresponding to the oxygen content setting value S. Based on this, the gas flow rate suitable for the target oxygen content can be given through parameter self-tuning to achieve the effect of saving gas flow; and the valve preset angle suitable for the target oxygen content can be given through parameter self-tuning, and then the opening angle of the auxiliary valve can be fine-tuned under the condition that the gas flow rate remains unchanged, so as to achieve the goal of low oxygen / slightly positive pressure in the loading and unloading chamber, while maintaining the effect of stable airflow and pressure in the loading and unloading chamber.

[0153] More specifically, the PID regulation of the gas flow delivered by the gas flow regulator by the control device adopts an incremental PID:

[0154] ΔG=K p *(e(n)-e(n-1))+K i *e(n)+K d *(e(n)-2e(n-1)+e(n-2))

[0155] G = G + ΔG;

[0156] Where G is the PID output; ΔG is the output increment; K p is the proportionality coefficient; K i is the integration coefficient; K d is the differential coefficient; e(n) is the current oxygen content error, e(n-1) is the previous oxygen content error, and e(n-2) is the previous oxygen content error.

[0157] It should be noted that, in this application, multiple oxygen content setting values ​​can be set according to actual process requirements, and the gas flow rate and valve preset angle corresponding to each oxygen content setting value can be obtained in turn according to the above method. As shown in Table 3 below:

[0158] Table 3

[0159] Serial number Oxygen content setting value (ppm) Gas flow rate (slm / min) Valve preset angle (%) 1 S1 Q1 V1 2 S2 Q2 V2 3 S3 Q3 V3

[0160] As an optional embodiment, taking the current pressure value within the preset positive pressure safety range as the angle adjustment target, adjusting the opening angle of the auxiliary valve includes:

[0161] Every preset angle adjustment cycle, it is determined whether the current pressure value is within the preset positive pressure safety range;

[0162] If the current pressure value is greater than the maximum value of the preset positive pressure safety range, based on V last =V now +V i Calculate the opening angle V of the auxiliary valve last and adjust the current opening angle of the auxiliary valve to the angle to be opened V last ; Among them, V now is the current opening angle of the auxiliary valve; V i Adjust the angle for units;

[0163] If the current pressure value is less than the minimum value of the preset positive pressure safety range, based on V last =V now -V i Calculate the opening angle V of the auxiliary valve last and adjust the current opening angle of the auxiliary valve to the angle to be opened V last ;

[0164] If the current pressure value is within the preset positive pressure safety range, the current opening angle of the auxiliary valve is maintained.

[0165] In a specific application, during the parameter self-tuning process of the loading and unloading chamber, the control device adjusts the opening angle of the auxiliary valve in a segmented self-adjusting manner (the adjustment range is 0 to 100, i.e., 0% to 100% angle): every preset angle adjustment cycle, it is determined whether the current pressure value P of the loading and unloading chamber is within the preset positive pressure safety range [P min , P max ], if P>P max , then based on V last =V now +V i (V i =1 represents 1% angle) calculate the auxiliary valve to be opened angle V last and the current opening angle V of the auxiliary valve now Adjust to the opening angle V last ; If P<P min , then based on V last =V now -V i Calculate the opening angle V of the auxiliary valve last and the current opening angle V of the auxiliary valve now Adjust to the opening angle V last If P min ≤P≤P max , then maintain the current opening angle of the auxiliary valve, that is, V last =V now .

[0166] It should be noted that, based on the characteristics of large oxygen content hysteresis in the loading and unloading chamber and immediate response of the pressure value in the loading and unloading chamber, the calculation cycle of the segmented self-adjustment of the auxiliary valve (the above-mentioned angle adjustment cycle) is greater than the calculation cycle of the PID adjustment of the gas flow delivered by the gas flow regulator. The calculation cycle of the PID adjustment is T n (e.g. 2s), the operation cycle of the sub-valve segmented self-adjustment is T p =60*T n .

[0167] In addition, if the control device obtains a large difference between the final stable gas flow delivered by the gas flow regulator and the opening angle of the auxiliary valve during the oxygen and pressure control process of the loading and unloading chamber and the gas flow and valve preset angle corresponding to the target oxygen content obtained during the self-tuning process of the loading and unloading chamber parameters, a reminder can be given to see whether the parameters need to be re-self-tuned, or the gas flow and valve preset angle corresponding to the target oxygen content can be updated accordingly based on the final stable gas flow delivered by the gas flow regulator and the opening angle of the auxiliary valve obtained during the oxygen and pressure control process of the loading and unloading chamber, depending on the actual situation.

[0168] In summary, if Figure 7 As shown, the control device can be programmed into three modules through software programming: a fuzzy controller (for controlling the auxiliary valve - butterfly valve), a segmented controller (for controlling the gas flow regulator MFC), and a parameter self-tuning device (for parameter self-tuning). The three together cooperate to implement the steps of any of the above-mentioned oxygen and pressure control methods for loading and unloading chambers.

[0169] The present application also provides a semiconductor process furnace, comprising: a control device, a loading and unloading chamber, and an oxygen and pressure control device, wherein:

[0170] Oxygen and pressure control equipment includes:

[0171] A detection device for detecting the oxygen content and the pressure value in the loading and unloading chamber;

[0172] A gas flow regulator provided on the air intake pipe of the loading and unloading chamber for controlling the air intake flow of the air intake pipe;

[0173] A valve provided on the exhaust pipe of the loading and unloading chamber for controlling the exhaust volume of the exhaust pipe;

[0174] The control device is connected to the detection device, the gas flow regulator and the valve respectively, and is used to execute any of the above-mentioned oxygen and pressure control methods for the loading and unloading chamber of a semiconductor process furnace.

[0175] For an introduction to the semiconductor process furnace provided in this application, please refer to the above-mentioned embodiments of the oxygen and pressure control method, and this application will not go into details here.

[0176] Those skilled in the art may appreciate that, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0177] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and need not be used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, which is only to describe the distinction mode adopted by the objects of the same attributes when describing in the embodiments of the present application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0178] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.< / y>

Claims

1. A method for controlling oxygen and pressure in a loading and unloading chamber of a semiconductor process furnace, characterized in that: Applicable to oxygen and pressure control equipment; the oxygen and pressure control equipment comprises: a detection device for detecting the oxygen content and the pressure value in the loading and unloading chamber, a gas flow regulator provided on the air intake pipe of the loading and unloading chamber for controlling the air intake flow of the air intake pipe, and a valve provided on the air exhaust pipe of the loading and unloading chamber for controlling the air exhaust flow of the air exhaust pipe; the oxygen and pressure control method comprises: When oxygen control of the loading and unloading chamber begins, the valve is controlled to open at a preset first angle, and the gas flow regulator is controlled to deliver oxygen-controlling gas into the loading and unloading chamber at a preset first gas flow rate, so as to discharge oxygen in the loading and unloading chamber; Obtaining the oxygen content and the pressure value in the loading and unloading chamber detected by the detection device; After the oxygen content reaches the preset target oxygen content, the gas flow delivered by the gas flow regulator and the opening angle of the valve are adjusted to meet the adjustment target, with the oxygen content reaching the preset target oxygen content and the pressure value being within a preset positive pressure safety range to prevent outside air from entering the loading and unloading chamber.

2. The oxygen and pressure control method according to claim 1, characterized in that: The exhaust pipe includes: a main exhaust pipe and an auxiliary exhaust pipe; the valve includes: a main valve arranged on the main exhaust pipe for controlling the opening and closing of the main exhaust pipe, and an auxiliary valve arranged on the auxiliary exhaust pipe for controlling the exhaust volume of the auxiliary exhaust pipe; Then, when the oxygen control of the loading and unloading chamber begins, the valve is controlled to open at a preset first angle, including: When oxygen control of the loading and unloading chamber begins, based on the correspondence between the preset oxygen content setting value and the preset valve angle, a target valve preset angle corresponding to the preset target oxygen content is determined, and the main valve is controlled to open the main exhaust pipe, and the auxiliary valve is controlled to open at the target valve preset angle; After the oxygen content reaches the preset target oxygen content, the gas flow rate delivered by the gas flow regulator and the opening angle of the valve are adjusted to meet the adjustment target when the oxygen content reaches the preset target oxygen content and the pressure value is within the preset positive pressure safety range, including: After the oxygen content reaches the preset target oxygen content, the main valve is controlled to close the main exhaust pipe, and the gas flow delivered by the gas flow regulator and the opening angle of the auxiliary valve are adjusted to meet the adjustment target when the oxygen content reaches the preset target oxygen content and the pressure value is within the preset positive pressure safety range.

3. The oxygen and pressure control method according to claim 2, characterized in that: The oxygen content reaches the preset target oxygen content, and the pressure value is within the preset positive pressure safety range as the adjustment target, and the gas flow delivered by the gas flow regulator and the opening angle of the auxiliary valve are adjusted to meet the adjustment target, including: Based on the correspondence between the preset oxygen content setting value and the gas flow rate, determining a target gas flow rate corresponding to the preset target oxygen content, and adjusting the gas flow rate delivered by the gas flow rate regulator to the target gas flow rate; After the gas flow delivered by the gas flow regulator is adjusted to the target gas flow, the opening angle of the auxiliary valve is controlled based on a preset valve control strategy to control the oxygen content at the preset target oxygen content and the pressure value within a preset positive pressure safety range.

4. The oxygen and pressure control method according to claim 3, characterized in that: The step of adjusting the gas flow rate delivered by the gas flow regulator to the target gas flow rate comprises: directly adjusting the gas flow delivered by the gas flow regulator from the first gas flow to a preset second gas flow; wherein the first gas flow>the second gas flow>the target gas flow; At every preset flow rate adjustment cycle, determining whether the gas flow rate currently delivered by the gas flow rate regulator is greater than the target gas flow rate; If so, based on Y last =Y now -t1*R1 calculates the flow rate Y to be adjusted corresponding to the gas flow regulator last , and adjust the gas flow rate currently delivered by the gas flow regulator to the flow rate to be adjusted; wherein, Y now is the gas flow rate currently delivered by the gas flow regulator; t1 is the flow rate regulation period; R1 is the preset flow rate regulation step rate; If not, the gas flow rate currently delivered by the gas flow regulator is maintained at the target gas flow rate.

5. The oxygen and pressure control method according to claim 3, characterized in that: The controlling the opening angle of the auxiliary valve based on the preset valve control strategy to control the oxygen content at the preset target oxygen content and the pressure value within a preset positive pressure safety range includes: The pressure value is fuzzified to obtain a first fuzzy value, and the oxygen content difference between the oxygen content and the preset target oxygen content is fuzzified to obtain a second fuzzy value; Inferring the first fuzzy quantity and the second fuzzy quantity according to a preset control rule to obtain an inference result, and clarifying the inference result to obtain an angle deviation value; The angle deviation value is added to the current opening angle of the auxiliary valve to obtain the angle to be opened of the auxiliary valve, and the current opening angle of the auxiliary valve is adjusted to the angle to be opened, so as to control the oxygen content difference to be less than the preset error threshold and control the pressure value within the preset positive pressure safety range.

6. The oxygen and pressure control method according to claim 5, characterized in that: The fuzzy processing of the pressure value to obtain a first fuzzy value, and the fuzzy processing of the oxygen content difference between the oxygen content and the preset target oxygen content to obtain a second fuzzy value include: The fuzzy mapping value y1 corresponding to the pressure value P is calculated according to y1=(P-(a1+b1) / 2)*k1; wherein a1 is the lower limit of the physical domain of the pressure value; b1 is the upper limit of the physical domain of the pressure value; k1 is the quantization factor of the pressure value, k1=2*n1 / (b1-a1); n1 is the upper limit of the fuzzy domain of the pressure value; Determine a first fuzzy quantity corresponding to the fuzzy mapping value y1 from a fuzzy subset of the fuzzy domain of the pressure value, and determine a membership degree of the first fuzzy quantity according to a membership function of the first fuzzy quantity; The fuzzy mapping value y2 corresponding to the oxygen content difference e is calculated according to y2=(e-(a2+b2) / 2)*k2; wherein a2 is the lower limit of the physical domain of the oxygen content difference; b2 is the upper limit of the physical domain of the oxygen content difference; k2 is the quantization factor of the oxygen content difference, k2=2*n2 / (b2-a2); n2 is the upper limit of the fuzzy domain of the oxygen content difference; A second fuzzy quantity corresponding to the fuzzy mapping value y2 is determined from a fuzzy subset of the fuzzy universe of the oxygen content difference, and a membership degree of the second fuzzy quantity is determined according to a membership function of the second fuzzy quantity.

7. The oxygen and pressure control method according to claim 6, characterized in that: The inference of the first fuzzy quantity and the second fuzzy quantity according to a preset control rule to obtain an inference result, and clarification processing of the inference result to obtain an angle deviation value includes: determining whether the first fuzzy quantity and the second fuzzy quantity are within a fuzzy control range or a flow rate increment control range; If it is within the fuzzy control range, a first fuzzy inference amount corresponding to the first fuzzy amount and the second fuzzy amount is determined according to the preset corresponding relationship between the fuzzy amount of the pressure value, the fuzzy amount of the oxygen content difference and the fuzzy inference amount, and the minimum degree of membership between the first fuzzy amount and the second fuzzy amount is used as the degree of membership of the first fuzzy inference amount, so as to clarify the first fuzzy inference amount and obtain the angle deviation value; If it is within the flow rate increasing control range, the inference result is determined to be flow rate increasing control, and the inference result is clarified to obtain an angle deviation value of 0, and the gas flow rate delivered by the gas flow regulator is controlled to increase until the first fuzzy quantity and the second fuzzy quantity enter the fuzzy control range.

8. The oxygen and pressure control method according to claim 7, characterized in that: The step of performing clarification processing on the first fuzzy inference amount to obtain an angle deviation value includes: If there are multiple first fuzzy inference quantities, selecting a target fuzzy inference quantity with the largest membership degree from the first fuzzy inference quantities; Determining a target fuzzy subset corresponding to the target fuzzy inference amount from the fuzzy subsets of the fuzzy domain of the angle deviation value; Based on the fact that multiple relational expressions in the membership function of the target fuzzy subset are all equal to the membership degree of the target fuzzy inference quantity, multiple equations are established, and the solution results of the multiple equations are averaged to obtain an average value; According to ΔU=k u ×m+(c+d) / 2 to calculate the angle deviation value ΔU; where k u is the proportional factor of the angle deviation value, k u =(d-c) / (2*n3); n3 is the upper limit of the fuzzy domain of the angle deviation value; m is the average value; c is the lower limit of the physical domain of the angle deviation value; d is the upper limit of the physical domain of the angle deviation value.

9. The oxygen and pressure control method according to any one of claims 3 to 8, characterized in that: The corresponding relationship between the oxygen content setting value and the preset valve angle, and the corresponding relationship between the oxygen content setting value and the gas flow rate are preset in the process of: When the loading and unloading chamber is subjected to parameter self-tuning, the main valve is controlled to open the main exhaust pipe, the auxiliary valve is controlled to open at a preset second angle, and the gas flow regulator is controlled to deliver the oxygen-controlling gas into the loading and unloading chamber at a preset second gas flow rate; Acquiring the current oxygen content and the current pressure value in the loading and unloading chamber detected by the detection device; After the current oxygen content reaches the oxygen content setting value, controlling the main valve to close the main exhaust pipe, and performing PID regulation on the gas flow delivered by the gas flow regulator based on the current error between the current oxygen content and the oxygen content setting value; After the current oxygen content reaches the oxygen content set value again, the opening angle of the auxiliary valve is adjusted with the current pressure value within the preset positive pressure safety range as the angle adjustment target, and the gas flow delivered by the gas flow regulator is continuously PID-regulated; When the current oxygen content reaches the oxygen content setting value and the current pressure value is within the preset positive pressure safety range, the gas flow currently delivered by the gas flow regulator is used as the gas flow corresponding to the oxygen content setting value, and the current opening angle of the auxiliary valve is used as the valve preset angle corresponding to the oxygen content setting value.

10. The oxygen and pressure control method according to claim 9, characterized in that: The adjusting the opening angle of the auxiliary valve by taking the current pressure value within the preset positive pressure safety range as the angle adjustment target comprises: At every preset angle adjustment cycle, it is determined whether the current pressure value is within a preset positive pressure safety range; If the current pressure value is greater than the maximum value of the preset positive pressure safety range, then based on V last =V now +V i Calculate the opening angle V of the auxiliary valve last and adjust the current opening angle of the auxiliary valve to the angle to be opened V last ; Among them, V now is the current opening angle of the auxiliary valve; V i Adjust the angle for units; If the current pressure value is less than the minimum value of the preset positive pressure safety range, then based on V last =V now -V i Calculate the opening angle V of the auxiliary valve last and adjust the current opening angle of the auxiliary valve to the angle to be opened V last ; If the current pressure value is within the preset positive pressure safety range, the current opening angle of the auxiliary valve is maintained.

11. A semiconductor process furnace, characterized in that: include: Control device, loading and unloading chamber and oxygen and pressure control equipment, among which, The oxygen and pressure control equipment comprises: A detection device for detecting the oxygen content and the pressure value in the loading and unloading chamber; A gas flow regulator provided on the air intake pipe of the loading and unloading chamber for controlling the air intake flow of the air intake pipe; A valve provided on the exhaust pipe of the loading and unloading chamber for controlling the exhaust volume of the exhaust pipe; The control device is connected to the detection device, the gas flow regulator and the valve respectively, and is used to execute the oxygen and pressure control method for the loading and unloading chamber of a semiconductor process furnace as described in any one of claims 1-10.

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