Reaction chamber pressure control method, device and semiconductor process equipment

Abstract

The present invention provides a pressure control method, comprising: obtaining the actual gas pressure value of a reaction chamber; calculating the pressure change rate of the actual gas pressure value within a preset time in real time, and determining the corresponding hysteresis conversion coefficient according to the pressure change rate, wherein the hysteresis conversion coefficient is a negative number and the absolute value thereof is positively correlated with the absolute value of the pressure change rate; multiplying the hysteresis conversion coefficient by the coefficient of the initial feedback control equation to obtain a corrected feedback control equation, calculating the opening adjustment amount of the pressure regulating valve according to the corrected feedback control equation, and adjusting the opening of the pressure regulating valve according to the opening adjustment amount until the actual gas pressure value reaches the target pressure. The method provided by the present invention can reversely adjust the opening of the pressure regulating valve before the gas pressure reaches the target pressure, thereby avoiding pressure overshoot and improving the pressure stability of the reaction chamber. The present invention also provides a pressure control device and semiconductor process equipment for a reaction chamber.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor process equipment, and in particular, to a pressure control method for a reaction chamber, a pressure control device for a reaction chamber for implementing the method, and a semiconductor process equipment comprising the device. Background Art

[0002] In the field of semiconductor manufacturing, the oxidation furnace is one of the most important equipment. The hydrogen (H2), chlorine (HCL), excess oxygen (O2), a small amount of dichloroethylene (C2H2Cl2) and nitrogen (N2) entering the reaction chamber of the oxidation furnace need to react chemically under a constant pressure to ensure the thickness of the coating. The pressure in the reaction chamber greater than or less than the set pressure will affect the thickness of the coating, so the pressure in the reaction chamber must be stable.

[0003] In existing semiconductor process equipment, the pressure in the reaction chamber is usually adjusted by proportional integral differential (PID) regulation. However, although this regulation method can respond quickly according to the real-time pressure inside the process chamber, due to the common hysteresis characteristics of the pressure system, rapid regulation is prone to overshoot, resulting in large pressure fluctuations in the reaction chamber, affecting the stability of the semiconductor process. If the control coefficient in the proportional integral differential formula is reduced, the pressure regulation efficiency will be too low.

[0004] Therefore, how to provide a pressure control method that can improve the pressure stability of the reaction chamber has become a technical problem that needs to be solved urgently in this field. Summary of the invention

[0005] The present invention aims to provide a reaction chamber pressure control method, a reaction chamber pressure control device and semiconductor process equipment, which can solve the overshoot problem in the reaction chamber pressure control process and improve the stability of the reaction chamber pressure.

[0006] To achieve the above object, as one aspect of the present invention, a method for controlling the pressure of a reaction chamber is provided, wherein a pressure regulating valve is provided on an air inlet pipeline or an exhaust pipeline of the reaction chamber, and the method comprises:

[0007] Obtaining an actual gas pressure value of the reaction chamber;

[0008] Calculate in real time the pressure change rate of the actual gas pressure value within a preset time, and determine a corresponding hysteresis conversion coefficient according to the pressure change rate, wherein the hysteresis conversion coefficient is a negative number and the absolute value of the hysteresis conversion coefficient is positively correlated with the absolute value of the pressure change rate;

[0009] The hysteresis conversion coefficient is multiplied by the coefficient of the initial feedback control equation to obtain a revised feedback control equation, the opening adjustment amount of the pressure regulating valve is calculated according to the revised feedback control equation, and the opening of the pressure regulating valve is adjusted according to the opening adjustment amount until the actual gas pressure value reaches the target pressure.

[0010] Optionally, the method specifically includes:

[0011] Obtaining an actual gas pressure value of the reaction chamber;

[0012] When the absolute value of the difference between the actual gas pressure value and the target pressure is greater than or equal to a preset threshold, adjusting the opening of the pressure regulating valve based on an initial feedback control equation so that the actual gas pressure value approaches the target pressure;

[0013] When the absolute value of the difference between the actual gas pressure value and the target pressure is less than the preset threshold and the actual gas pressure value does not reach the target pressure, calculating the opening adjustment amount of the pressure regulating valve according to the corrected feedback control equation;

[0014] After the actual gas pressure value reaches the target pressure, the opening of the pressure regulating valve continues to be adjusted based on the initial feedback control equation.

[0015] Optionally, determining a corresponding hysteresis conversion coefficient according to the pressure change rate includes:

[0016] Calculating a hysteresis coefficient based on the pressure change rate;

[0017] Multiplying the hysteresis coefficient by a preset coefficient to obtain the hysteresis conversion coefficient;

[0018] The hysteresis coefficient is less than 0, and the absolute value of the hysteresis coefficient gradually changes from 1 to 0 along with the absolute value of the pressure change rate, and the preset coefficient is a positive number.

[0019] Optionally, determining a corresponding hysteresis conversion coefficient according to the pressure change rate includes:

[0020] Calculating a hysteresis coefficient and a first-order derivative value of the pressure change rate according to the pressure change rate;

[0021] Multiplying the hysteresis coefficient by the absolute value of the first-order derivative value of the pressure change rate to obtain the hysteresis conversion coefficient;

[0022] The hysteresis coefficient is less than 0, and the absolute value of the hysteresis coefficient gradually changes from 1 to 0 along with the absolute value of the pressure change rate.

[0023] Optionally, the hysteresis coefficient is a linear function of the pressure change rate.

[0024] Optionally, determining a corresponding hysteresis conversion coefficient according to the pressure change rate includes:

[0025] Based on a pre-stored comparison table, the hysteresis conversion coefficient corresponding to the pressure change rate is selected.

[0026] Optionally, the method for establishing the comparison table includes:

[0027] Based on different pressure control systems, different pressure change rates can be obtained by adjusting the gas pressure or gas flow rate;

[0028] Adjusting the hysteresis conversion coefficient so that the actual gas pressure value reaches the target pressure value within the target time;

[0029] The hysteresis conversion coefficients corresponding to different pressure change rates are recorded to form the comparison table corresponding to each pressure control system.

[0030] Optionally, the initial feedback control equation is a proportional-integral-differential control equation, and the hysteresis conversion coefficient is multiplied by the proportional term coefficient of the initial feedback control equation to obtain the corrected feedback control equation.

[0031] Optionally, the preset threshold is 0.5-1% of the target pressure.

[0032] As a second aspect of the present invention, a pressure control device for a reaction chamber is provided, the pressure control device comprising a pressure detection module, a pressure input module, a pressure regulating valve and a controller, the pressure detection module and the pressure regulating valve being used to be arranged on an air inlet line or an exhaust line of the reaction chamber, the pressure input module being used to provide a target pressure to the controller in response to a user input operation; the controller being used to obtain an actual gas pressure value of the reaction chamber through the pressure detection module, and to adjust the opening of the pressure regulating valve based on the pressure control method for the reaction chamber described above.

[0033] As a third aspect of the present invention, a semiconductor process equipment is provided, including a reaction chamber and a pressure control device, wherein the pressure control device is the pressure control device for the reaction chamber described above.

[0034] In the pressure control method for a reaction chamber, the pressure control device for a reaction chamber, and the semiconductor process equipment provided by the present invention, the pressure control device can determine the corresponding hysteresis conversion coefficient according to the pressure change rate of the actual gas pressure value, multiply the hysteresis conversion coefficient by the coefficient of the initial feedback control equation to obtain a revised feedback control equation, and calculate the opening adjustment amount of the pressure regulating valve according to the revised feedback control equation until the actual gas pressure value reaches the target pressure. Thus, before the actual gas pressure value is about to reach the target pressure, the pressure control device reversely adjusts the opening of the pressure regulating valve, thereby avoiding pressure overshoot and improving the pressure stability of the reaction chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0036] Figure 1 is a schematic structural diagram of a semiconductor process equipment provided by an embodiment of the present invention;

[0037] Figure 2 It is a schematic diagram of the hysteresis curve corresponding to different systems;

[0038] Figure 3 is a schematic flow chart of a pressure control method for a reaction chamber provided in an embodiment of the present invention;

[0039] Figure 4 is a schematic structural diagram of a pressure control device for a reaction chamber provided in an embodiment of the present invention;

[0040] Figure 5 It is a schematic diagram of a partial process of a method for controlling the pressure of a reaction chamber provided by an embodiment of the present invention;

[0041] Figure 6 It is a schematic diagram of a partial process of a method for controlling the pressure of a reaction chamber provided in another embodiment of the present invention. DETAILED DESCRIPTION

[0042] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0043] To solve the above technical problems, as one aspect of the present invention, a pressure control method for a reaction chamber is provided. A pressure regulating valve 3 is provided on an air inlet or exhaust pipe of the reaction chamber 1 (for example, Figure 1 As shown, the reaction chamber 1 is exhausted through an exhaust pipeline, and a pressure regulating valve 3 is provided on the exhaust pipeline. The pressure control method (implemented by a controller 5) includes:

[0044] Obtaining an actual gas pressure value P of the reaction chamber 1;

[0045] Real-time calculation of the pressure change rate V of the actual gas pressure value P within the preset time P , and according to the pressure change rate V P , determine the corresponding hysteresis conversion coefficient τn(V P ), hysteresis conversion coefficient τn(V P ) is negative and the hysteresis conversion coefficient τn(V P ) and the pressure change rate V P The absolute value of is positively correlated;

[0046] The hysteresis conversion coefficient τn(V P ) is multiplied by the coefficient of the initial feedback control equation to obtain a revised feedback control equation, the opening adjustment amount of the pressure regulating valve 3 is calculated according to the revised feedback control equation, and the opening of the pressure regulating valve 3 is adjusted according to the opening adjustment amount until the actual gas pressure value P reaches the target pressure (i.e., the set point (SetPoint, SP) of the gas pressure).

[0047] In the pressure control method of the reaction chamber provided by the present invention, the controller 5 can control the pressure change rate V of the actual gas pressure value P according to the pressure change rate V of the actual gas pressure value P. P , determine the corresponding hysteresis conversion coefficient τn(V P ), the hysteresis conversion coefficient τn(V P ) is multiplied by the coefficient of the initial feedback control equation to obtain a revised feedback control equation, and the opening adjustment amount of the pressure regulating valve 3 is calculated according to the revised feedback control equation until the actual gas pressure value P reaches the target pressure, so that the controller 5 reversely adjusts the opening of the pressure regulating valve 3 before the actual gas pressure value P is about to reach the target pressure SP, thereby avoiding pressure overshoot.

[0048] Specifically, the pressure change rate V P is the first-order derivative of the actual gas pressure value P (i.e. V P =dP / dt), the greater the rate at which the actual gas pressure value P changes (i.e., the pressure change rate V P The absolute value of V P | is larger), the more likely the actual gas pressure value P will overshoot after reaching the target pressure SP (i.e., continue to increase or decrease after exceeding the target pressure SP), so the hysteresis conversion coefficient τn (V P ) with the pressure change rate V P Absolute value |V PThat is, the greater the real-time change rate of the actual gas pressure value P, the greater the absolute value of the hysteresis conversion coefficient τn (V P ) is multiplied by the coefficient of the initial feedback control equation to strengthen the reverse adjustment of the opening of the pressure regulating valve 3 when calculating the opening adjustment amount according to the revised feedback control equation, so that the rate of change of the actual gas pressure value P before reaching the target pressure SP quickly approaches zero (that is, the pressure change rate V P tends to zero), thereby effectively preventing gas pressure overshoot and improving the pressure stability of the reaction chamber.

[0049] As an optional implementation of the present invention, the initial feedback control equation is a proportional integral differential (PID) control equation, expressed as f=P+I+D, where f is the PID output, P represents the proportional term (proportional link), I represents the integral term (integral link), and D represents the differential term (differential link). P ) is multiplied by the proportional term coefficient of the initial feedback control equation to obtain the modified feedback control equation.

[0050] Alternatively, in some embodiments of the present invention, the initial feedback control equation may include only some of the terms in the proportional-integral-differential control equation, for example, only the proportional term P and the integral term I, or only the proportional term P and the differential term D. Since the proportional term is the main factor determining the magnitude of the adjustment in the proportional-integral-differential control equation, the hysteresis conversion coefficient τn(V P ) is multiplied by the proportional term coefficient of the initial feedback control equation.

[0051] To ensure the efficiency of the reaction chamber pressure regulation, as a preferred embodiment of the present invention, the step of correcting the feedback control equation can be performed only after the actual gas pressure value P approaches the target pressure SP. Specifically, Figure 3 As shown, the pressure control method specifically includes:

[0052] Step S1, obtaining the actual gas pressure value P of the reaction chamber 1;

[0053] Step S2, when the absolute value |ΔP| of the difference ΔP between the actual gas pressure value P and the target pressure is greater than or equal to a preset threshold, adjusting the opening of the pressure regulating valve 3 based on the initial feedback control equation (and according to the difference ΔP) so that the actual gas pressure value P approaches the target pressure;

[0054] Step S3, when the absolute value |ΔP| of the difference ΔP between the actual gas pressure value P and the target pressure is less than the preset threshold and the actual gas pressure value P has not reached the target pressure, the opening adjustment amount of the pressure regulating valve 3 is calculated according to the modified feedback control equation, and the opening of the pressure regulating valve 3 is adjusted according to the opening adjustment amount until the actual gas pressure value P reaches the target pressure;

[0055] Step S4: After the actual gas pressure value P reaches the target pressure, continue to adjust the opening of the pressure regulating valve 3 based on the initial feedback control equation.

[0056] In an embodiment of the present invention, after the absolute value |ΔP| of the difference ΔP between the actual gas pressure value P and the target pressure SP is reduced to a preset threshold, the controller 5 multiplies the hysteresis conversion coefficient τn(VP) by the coefficient of the initial feedback control equation to obtain a corrected feedback control equation, and calculates the opening adjustment amount of the pressure regulating valve 3 according to the corrected feedback control equation, so that when the difference between the actual gas pressure value P and the target pressure SP is large (|ΔP| is greater than the preset threshold), the initial feedback control equation is still used to efficiently adjust the fluid flow rate, and when the actual gas pressure value P is about to reach the target pressure SP, the controller 5 reversely adjusts the opening of the pressure regulating valve 3 to avoid pressure overshoot, thereby improving the pressure stability of the reaction chamber while ensuring the pressure regulation efficiency of the reaction chamber.

[0057] To ensure the pressure regulation efficiency of the reaction chamber, the preset threshold should not be set too large. For example, as an optional embodiment of the present invention, the preset threshold may be 0.5-1% of the target pressure, that is, 0.5-1% SP.

[0058] For example, the preset threshold is 1%. During the period when the absolute value |ΔP| of the difference ΔP between the actual gas pressure value P and the target pressure SP is greater than the preset threshold 1% SP, the opening of the pressure regulating valve 3 is feedback-adjusted based on the initial feedback control equation, so that the actual gas pressure value P quickly approaches the target pressure SP. After the absolute value |ΔP| of the difference ΔP between the actual gas pressure value P and the target pressure SP is reduced to 1% SP, the revised feedback control equation is used to reversely adjust the opening of the pressure regulating valve 3, so that the rate of change of the actual gas pressure value P quickly approaches zero, thereby avoiding overshoot.

[0059] As an optional embodiment of the present invention, the pressure regulating valve 3 includes a stepper motor and a piston valve. The piston valve is arranged on the corresponding air inlet pipeline or the air outlet pipeline. The output shaft of the stepper motor is connected to the piston of the piston valve. The controller 5 is used to calculate the opening adjustment amount of the pressure regulating valve 3 in each control cycle, and then send a control signal corresponding to the opening adjustment amount to the stepper motor, so that the stepper motor pulls the piston out of the sleeve of the piston valve or pushes the piston into the sleeve, so as to increase or decrease the opening of the piston valve (pressure regulating valve 3).

[0060] As a preferred embodiment of the present invention, the output shaft of the stepper motor is connected to the piston of the piston valve through an elastic member (such as a spring). The elastic member has elasticity, so that under the elastic force of the spring, the system can achieve a pressure change rate V P Automatic buffer adjustment is performed when the control ability is poor or even no control is available to reduce the impact of overshoot.

[0061] In other embodiments of the present invention, the pressure regulating valve 3 may also adopt a structure in which a stepping motor drives other types of valves, such as a butterfly valve, a needle valve, a ball valve, etc.

[0062] As an optional embodiment of the present invention, Figure 4 As shown, a pressure detection module 2 is also provided on the exhaust pipeline (or intake pipeline) corresponding to the pressure regulating valve 3, which is used to detect the gas pressure in the exhaust pipeline (or intake pipeline) to obtain a pressure simulation signal. The controller 5 is used to determine the actual gas pressure value P in real time according to the pressure simulation signal (converting analog to digital), and to determine the change rate V of the actual gas pressure value P in real time according to the actual gas pressure value P. P .

[0063] As an optional implementation of the present invention, the pressure detection module 2 may be a vacuum pressure gauge, which directly measures the pressure in the reaction chamber to obtain the actual gas pressure value P.

[0064] As an optional embodiment of the present invention, the judgment condition that the actual gas pressure value P reaches the target pressure is: the actual gas pressure value P is consistent with the target pressure, that is, when the actual gas pressure value P detected by the pressure detection module 2 is equal to the target pressure, it is considered that the actual gas pressure value P has increased to the target pressure or decreased to the target pressure.

[0065] To facilitate understanding by technicians, the following provides principle analysis of two situations in which the pressure control method provided in the embodiment of the present invention is used to adjust the opening of the front end of the gas path of the reaction chamber 1 (i.e., the opening of the pressure regulating valve 3 on the exhaust pipeline):

[0066] When the initial actual gas pressure value P is lower than the target pressure SP (and the absolute value of the difference ΔP |ΔP| is greater than a preset threshold), the opening of the pressure regulating valve 3 is first adjusted based on the initial feedback control equation, that is, the opening adjustment amount of the pressure regulating valve 3 corresponding to each control cycle is determined according to the difference ΔP between the actual gas pressure value P and the target pressure, and the opening of the pressure regulating valve 3 is periodically adjusted to control the opening of the pressure regulating valve 3 to decrease, so that the actual gas pressure value P increases rapidly to approach the target pressure;

[0067] When the actual gas pressure value P increases to be close enough to the target pressure SP (i.e., |ΔP| decreases to be less than the preset threshold), the controller 5 determines the hysteresis conversion coefficient τn (V P ) and in each control cycle, the opening of the pressure regulating valve 3 is reversely adjusted based on the modified feedback control equation, so that the opening of the pressure regulating valve 3 increases, and the greater the rate of increase of the actual gas pressure value P (i.e., the pressure change rate V P The absolute value of V P | is larger), the greater the reverse adjustment amount of the pressure regulating valve 3 to be opened, thereby quickly reducing the rising rate of the actual gas pressure value P, so that the change curve (pressure-time curve) of the actual gas pressure value P gradually tends to be gentle. When the gas pressure in the reaction chamber 1 rises to the point where the actual gas pressure value P detected by the pressure detection module 2 is equal to the target pressure, it is considered that the actual gas pressure value P has increased to the target pressure, and the opening of the pressure regulating valve 3 is feedback-adjusted again based on the initial feedback control equation to keep the actual gas pressure value P at the target pressure.

[0068] Similarly, when the initial actual gas pressure value P is higher than the target pressure SP (and the absolute value of the difference ΔP |ΔP| is greater than the preset threshold), the opening of the pressure regulating valve 3 is first adjusted based on the initial feedback control equation, that is, the opening adjustment amount of the pressure regulating valve 3 corresponding to each control cycle is determined according to the difference ΔP between the actual gas pressure value P and the target pressure, and the opening of the pressure regulating valve 3 is periodically adjusted to control the opening of the pressure regulating valve 3 to increase, so that the actual gas pressure value P is quickly reduced to approach the target pressure;

[0069] When the actual gas pressure value P decreases to be close enough to the target pressure SP (i.e., |ΔP| decreases to be less than the preset threshold), the controller 5 determines the hysteresis conversion coefficient τn (V P ) and in each control cycle, the opening of the pressure regulating valve 3 is reversely adjusted based on the modified feedback control equation, so that the opening of the pressure regulating valve 3 is reduced. The greater the rate of decrease of the actual gas pressure value P (i.e., the pressure change rate V P The absolute value of V P| is larger), the greater the reverse adjustment amount of the pressure regulating valve 3 to close is, so as to quickly reduce the decreasing rate of the actual gas pressure value P, and make the change curve of the actual gas pressure value P gradually tend to be gentle. When the gas pressure in the reaction chamber 1 is reduced to the point where the actual gas pressure value P detected by the pressure detection module 2 is equal to the target pressure, it is considered that the actual gas pressure value P has been reduced to the target pressure, and the opening of the pressure regulating valve 3 is feedback-adjusted again based on the initial feedback control equation to keep the actual gas pressure value P at the target pressure.

[0070] The principle of adjusting the opening of the rear end of the gas path of the reaction chamber 1 (i.e., the opening of the pressure regulating valve 3 on the air inlet pipeline) by using the pressure control method provided in the embodiment of the present invention is similar and will not be described in detail here.

[0071] As an optional embodiment of the present invention, Figure 5 As shown, in step S3, according to the pressure change rate V P Determine the corresponding hysteresis conversion coefficient τn(V P ) specifically include:

[0072] Step S301: According to the pressure change rate V P Calculate the hysteresis coefficient K(V P );

[0073] Step S302: Set the hysteresis coefficient K(V P ) is multiplied by the preset coefficient to obtain the hysteresis conversion coefficient τn(V P );

[0074] Among them, the hysteresis coefficient K(V P ) is less than 0, and the hysteresis coefficient K(V P ) with the pressure change rate V P The absolute value of changes gradually from 1 to 0, and the preset coefficient is a positive number. That is, the pressure change rate V P The absolute value of V P | is larger, the closer the coefficient of the proportional term is to the product of the initial proportional coefficient and the preset coefficient, and the pressure change rate V P The absolute value of V P The smaller | is, the closer the coefficient of the proportional term is to zero.

[0075] As an optional embodiment of the present invention, the preset coefficient may be the pressure change rate V when the absolute value |ΔP| of the difference ΔP between the actual gas pressure value P and the target pressure reaches the preset threshold. P That is to say, the pressure change rate V corresponding to the start time of step S3 for reverse regulation is selected. P (i.e. the absolute maximum pressure change rate V during reverse regulation) P ) as the preset coefficient.

[0076] To further optimize the pressure change rate V P As a preferred embodiment of the present invention, the reverse regulation effect is as follows: Figure 6 As shown, in step S3, according to the pressure change rate V P Determine the corresponding hysteresis conversion coefficient τn(V P ) specifically include:

[0077] Step S31: According to the pressure change rate V P Calculate the hysteresis coefficient K(V P ) and the pressure change rate V P The first derivative value of (i.e., d(V P ) / dt);

[0078] Step S32: The hysteresis coefficient and the pressure change rate V P The absolute value of the first derivative of is multiplied by the absolute value of the first derivative to obtain the hysteresis conversion coefficient τn (V P ), that is, τn(V P )=K(V P )*|d(V P ) / dt|;

[0079] Among them, the hysteresis coefficient K(V P ) is less than 0, and the hysteresis coefficient K(V P ) with the pressure change rate V P The absolute value of changes gradually from 1 to 0. In step S3, as the reverse regulation continues, the pressure change rate V P As the pressure change rate V approaches 0 P The first-order derivative value d(V P ) / dt also gradually approaches zero, so in the embodiment of the present invention, the hysteresis coefficient K(V P ) and pressure change rate V P The first-order derivative value d(V P ) / dt to enhance the hysteresis conversion factor τn(V P ) After the feedback control equation is modified, the pressure change rate V P reverse regulation effect.

[0080] As an optional embodiment of the present invention, the hysteresis coefficient K(V P ) is the pressure change rate V P A linear function of .

[0081] To improve the hysteresis conversion coefficient τn(V P ) efficiency, as a preferred embodiment of the present invention, in step S3, according to the pressure change rate V PDetermine the corresponding hysteresis conversion coefficient τn(V P ) specifically include:

[0082] Based on the pre-stored comparison table, select the pressure change rate V P The corresponding hysteresis conversion coefficient τn(V P ).

[0083] It should be noted that the hysteresis characteristics of different pressure control systems (the rate of change of the gas pressure in the reaction chamber 1 when the gas is introduced into the reaction chamber 1 at a predetermined flow rate or discharged from the reaction chamber 1 at a predetermined flow rate. That is, V P =dp / dt, where p represents the real-time pressure of the gas in the reaction chamber 1, and t represents the time) is different, for example, Figure 2 The figure shows a schematic diagram of the pressure-time curve (i.e., hysteresis curve) corresponding to the change in gas pressure under the same intake flow rate F for different pressure control systems. Different pressure systems, even if the intake flow rate is the same, still have differences in parameters such as cavity volume and plant exhaust capacity, which leads to differences in the pressure states of these systems. During the inflation process, the pressure of the system with a larger cavity rises slowly (for example, the pressure control system corresponding to the right curve of Sn is compared with the pressure control system corresponding to the left curve of S1), and the pressure of the system with a small cavity rises quickly (for example, the pressure control system corresponding to the left curve of S1 is compared with the pressure control system corresponding to the right curve of Sn).

[0084] Therefore, it is necessary to conduct experiments on each pressure control system to determine its corresponding comparison table. Specifically, as an optional implementation of the present invention, the method for establishing the comparison table includes:

[0085] Step S10: Based on different pressure control systems, different pressure change rates V are obtained by adjusting the gas pressure or gas flow rate. P ;

[0086] Step S20, adjust the hysteresis conversion coefficient τn (V P ), so that the actual gas pressure value P reaches the target pressure value within the target time;

[0087] Step S30, record different pressure change rates V P The corresponding hysteresis conversion coefficient τn(V P ) to form a corresponding comparison table for each pressure control system.

[0088] As a second aspect of the present invention, a pressure control device for a reaction chamber is provided, such as Figure 1As shown, the pressure control device includes a pressure detection module 2, a pressure input module 6, a pressure regulating valve 3 and a controller 5. The pressure detection module 2 and the pressure regulating valve 3 are used to be arranged on the intake pipe or the exhaust pipe of the reaction chamber 1 (when the pressure regulating valve 3 is arranged on the exhaust pipe, the pressure detection module 2 needs to be located upstream of the pressure regulating valve 3, and when the pressure regulating valve 3 is arranged on the intake pipe, the pressure detection module 2 needs to be located downstream of the pressure regulating valve 3 to ensure the accuracy of the actual gas pressure value P). The pressure input module 6 is used to provide a target pressure to the controller 5 in response to a user input operation; the controller 5 is used to obtain the actual gas pressure value P of the reaction chamber 1 through the pressure detection module 2, and adjust the opening of the pressure regulating valve 3 based on the pressure control method provided in an embodiment of the present invention.

[0089] In the pressure control device provided by the present invention, the controller 5 can adjust the pressure change rate V according to the actual gas pressure value P. P , determine the corresponding hysteresis conversion coefficient τn(V P ), the hysteresis conversion coefficient τn(V P ) is multiplied by the coefficient of the initial feedback control equation to obtain a revised feedback control equation, and the opening adjustment amount of the pressure regulating valve 3 is calculated according to the revised feedback control equation until the actual gas pressure value P reaches the target pressure, so that the controller 5 reversely adjusts the opening of the pressure regulating valve 3 before the actual gas pressure value P is about to reach the target pressure SP, thereby avoiding pressure overshoot and improving the pressure stability of the reaction chamber.

[0090] As an optional embodiment of the present invention, Figure 4 As shown, the controller 5 includes a valve opening adjustment module 55 and a hysteresis compensation control strategy module 56. The hysteresis compensation control strategy module 56 is used to determine the pressure change rate V according to the actual gas pressure value P. P , and according to the pressure change rate V P Determine the hysteresis conversion factor τn(V in real time P ), that is, execute step S3; the valve opening adjustment module 55 is used to convert the hysteresis conversion coefficient τn (V P ) is multiplied by the proportional term in the initial feedback control equation to obtain a revised feedback control equation, and according to the difference ΔP between the actual gas pressure value P and the target pressure and the revised feedback control equation, the opening adjustment amount of the pressure regulating valve 3 is calculated, and the opening of the pressure regulating valve 3 is adjusted according to the opening adjustment amount, that is, step S4 is executed.

[0091] As an optional embodiment of the present invention, the pressure detection module 2 is used to detect the actual gas pressure value in the exhaust pipeline (or the intake pipeline) to obtain a pressure simulation signal (that is, the actual gas pressure value P is sent to in the form of an analog quantity), such as Figure 4As shown, the controller 5 also includes a pressure calculation module 51 and a real-time pressure change rate calculation module 52. The pressure calculation module 51 is used to determine the actual gas pressure value P in real time according to the air pressure analog signal (performing analog-to-digital conversion), and the real-time pressure change rate calculation module 52 is used to determine the change rate dP / dt of the actual gas pressure value P in real time according to the actual gas pressure value P determined by the pressure calculation module 51 (specifically, the difference between the actual gas pressure value P before and after the preset time Δt is divided by the preset time Δt to obtain the change rate dP / dt of the actual gas pressure value P within the preset time Δt), that is, the pressure change rate V P .

[0092] As an optional embodiment of the present invention, the pressure detection module 2 may be a vacuum pressure gauge, which directly measures the pressure in the reaction chamber through the vacuum pressure gauge to obtain the actual gas pressure value P (and generates a corresponding analog signal).

[0093] Optionally, a vacuum generator 4 is further provided on the exhaust pipeline of the reaction chamber 1 at a position downstream of the pressure regulating valve 3, for providing negative pressure and regulating the gas suction force downstream to assist the normal operation of the pressure control system.

[0094] The above scheme is an absolute pressure control scheme, that is, the vacuum pressure gauge directly measures the pressure in the reaction chamber, and the pressure calculation module 1 performs analog-to-digital conversion to determine the actual gas pressure value P. In other embodiments of the present invention, the controller 5 can also be compatible with a relative pressure control scheme, that is, the pressure detection module 2 measures the difference between the pressure in the reaction chamber and the atmospheric pressure, and performs subsequent calculations on the difference.

[0095] As an optional embodiment of the present invention, Figure 4 As shown, the controller 5 further includes a pressure setting receiving module 53 for receiving a target pressure.

[0096] Specifically, Figure 1 As shown, the controller 5 is connected to the pressure input module 6 via the pressure setting receiving module 53. The user inputs and sets the target pressure via the pressure input module 6 (which may be an input device such as a keyboard), and the pressure input module 6 transmits the target pressure to the pressure setting receiving module 53, so that the user can appropriately change the target pressure according to the process flow.

[0097] Alternatively, if Figure 4 As shown, the controller 5 also includes a control coefficient part 54 for storing the parameters of the initial feedback control equation. For example, when the initial feedback control equation is a proportional-integral-differential control equation, the control coefficient part 54 can be used to store the proportional coefficient, integral coefficient and differential coefficient of the proportional-integral-differential control equation so that the valve opening adjustment module 55 can be called.

[0098] As a third aspect of the present invention, a semiconductor process equipment is provided, including a reaction chamber 1 and a pressure control device, wherein the pressure control device is the pressure control device of the reaction chamber provided in an embodiment of the present invention.

[0099] In the semiconductor process equipment provided by the present invention, the controller 5 can adjust the pressure change rate V of the actual gas pressure value P according to the pressure change rate V of the actual gas pressure value P. P , determine the corresponding hysteresis conversion coefficient τn(V P ), the hysteresis conversion coefficient τn(V P ) is multiplied by the coefficient of the initial feedback control equation to obtain a revised feedback control equation, and the opening adjustment amount of the pressure regulating valve 3 is calculated according to the revised feedback control equation until the actual gas pressure value P reaches the target pressure, so that the controller 5 reversely adjusts the opening of the pressure regulating valve 3 before the actual gas pressure value P is about to reach the target pressure SP, thereby avoiding pressure overshoot and improving the pressure stability of the reaction chamber.

[0100] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for controlling the pressure of a reaction chamber, wherein a pressure regulating valve is provided on an air inlet or exhaust pipe of the reaction chamber, characterized in that: The method comprises: Obtaining an actual gas pressure value of the reaction chamber; Calculate the pressure change rate of the actual gas pressure value within a preset time in real time, and determine the corresponding hysteresis conversion coefficient according to the pressure change rate, wherein the hysteresis conversion coefficient is a negative number and the absolute value of the hysteresis conversion coefficient is positively correlated with the absolute value of the pressure change rate, so as to reversely adjust the opening of the pressure regulating valve before the actual gas pressure value is about to reach the target pressure; The hysteresis conversion coefficient is multiplied by the coefficient of the initial feedback control equation to obtain a revised feedback control equation, the opening adjustment amount of the pressure regulating valve is calculated according to the revised feedback control equation, and the opening of the pressure regulating valve is adjusted according to the opening adjustment amount until the actual gas pressure value reaches the target pressure.

2. The pressure control method of a reaction chamber according to claim 1, characterized in that: The method specifically comprises: Obtaining an actual gas pressure value of the reaction chamber; When the absolute value of the difference between the actual gas pressure value and the target pressure is greater than or equal to a preset threshold, adjusting the opening of the pressure regulating valve based on the initial feedback control equation so that the actual gas pressure value approaches the target pressure; When the absolute value of the difference between the actual gas pressure value and the target pressure is less than the preset threshold and the actual gas pressure value does not reach the target pressure, calculating the opening adjustment amount of the pressure regulating valve according to the corrected feedback control equation; After the actual gas pressure value reaches the target pressure, the opening of the pressure regulating valve continues to be adjusted based on the initial feedback control equation.

3. The pressure control method of a reaction chamber according to claim 1, characterized in that: Determining a corresponding hysteresis conversion coefficient according to the pressure change rate includes: Calculating a hysteresis coefficient according to the pressure change rate to optimize the reverse regulation effect of the pressure change rate; Multiplying the hysteresis coefficient by a preset coefficient to obtain the hysteresis conversion coefficient; The hysteresis coefficient is less than 0, and the absolute value of the hysteresis coefficient gradually changes from 1 to 0 along with the absolute value of the pressure change rate, and the preset coefficient is a positive number.

4. The method for controlling the pressure of a reaction chamber according to claim 1, characterized in that: Determining a corresponding hysteresis conversion coefficient according to the pressure change rate includes: Calculating a hysteresis coefficient and a first-order derivative value of the pressure change rate according to the pressure change rate to optimize a reverse regulation effect on the pressure change rate; Multiplying the hysteresis coefficient by the absolute value of the first-order derivative value of the pressure change rate to obtain the hysteresis conversion coefficient; The hysteresis coefficient is less than 0, and the absolute value of the hysteresis coefficient gradually changes from 1 to 0 along with the absolute value of the pressure change rate.

5. The method for controlling the pressure of a reaction chamber according to claim 4, characterized in that: The hysteresis coefficient is a linear function of the pressure change rate.

6. The method for controlling the pressure of a reaction chamber according to claim 1, characterized in that: Determining a corresponding hysteresis conversion coefficient according to the pressure change rate includes: Based on a pre-stored comparison table, the hysteresis conversion coefficient corresponding to the pressure change rate is selected.

7. The method for controlling the pressure of a reaction chamber according to claim 6, characterized in that: The method for establishing the comparison table includes: Based on different pressure control systems, different pressure change rates can be obtained by adjusting the gas pressure or gas flow rate; Adjusting the hysteresis conversion coefficient so that the actual gas pressure value reaches the target pressure value within the target time; The hysteresis conversion coefficients corresponding to different pressure change rates are recorded to form the comparison table corresponding to each pressure control system.

8. The method for controlling the pressure of a reaction chamber according to claim 1, characterized in that: The initial feedback control equation is a proportional-integral-differential control equation, and the hysteresis conversion coefficient is multiplied by the proportional term coefficient of the initial feedback control equation to obtain the corrected feedback control equation.

9. The method for controlling the pressure of a reaction chamber according to claim 2, characterized in that: The preset threshold is 0.5-1% of the target pressure.

10. A pressure control device for a reaction chamber, characterized in that: The pressure control device includes a pressure detection module, a pressure input module, a pressure regulating valve and a controller. The pressure detection module and the pressure regulating valve are used to be arranged on the air inlet pipeline or the exhaust pipeline of the reaction chamber. The pressure input module is used to provide a target pressure to the controller in response to a user input operation; the controller is used to obtain the actual gas pressure value of the reaction chamber through the pressure detection module, and adjust the opening of the pressure regulating valve based on the pressure control method for the reaction chamber described in any one of claims 1 to 9.

11. A semiconductor process equipment, comprising a reaction chamber and a pressure control device, characterized in that: The pressure control device is the pressure control device of the reaction chamber according to claim 10.

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