Process control method and semiconductor heat treatment equipment

Abstract

The invention provides a process control method and semiconductor heat treatment equipment, and relates to the technical field of semiconductors, and the process control method comprises the steps: monitoring the quality of a wafer in the semiconductor heat treatment equipment in a process, and calculating the change rate of the quality of the wafer; when the change rate is not zero, the magnetofluid rotating speed, the air inlet rate and the air exhaust rate of the semiconductor heat treatment equipment are controlled based on the change rate until the change rate is zero; wherein the rotating speed of the magnetic fluid, the air inlet rate and the air exhaust rate are all in positive correlation with the change rate. According to the invention, the rotation speed of the wafer and the gas amount in the chamber are adjusted according to the reaction progress of the wafer, the process reaction time can be mastered more accurately, the uniformity of the diffusion process wafer is improved, the wafer and the reaction gas are ensured to fully react, the reaction progress is accelerated, the process reaction time is shortened, and the productivity is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a process control method and semiconductor heat treatment equipment. Background Art

[0002] With the rapid development of renewable energy, the photovoltaic industry is also developing rapidly. Diffusion equipment is an indispensable part of the photovoltaic production line, which diffuses boron or phosphorus sources on the surface of the wafer to form a PN junction. The quality of the wafers produced by the diffusion equipment has a great impact on the subsequent reprocessing. The uniformity between wafers is a key indicator to measure the quality of the wafer process.

[0003] Diffusion equipment includes horizontal diffusion equipment and vertical diffusion equipment. It is difficult for horizontal diffusion equipment to achieve further breakthroughs in production capacity and uniformity between wafers. Vertical diffusion equipment can place wafers horizontally due to its unique vertical furnace structure, achieving improved uniformity between wafers and production capacity. When the vertical diffusion equipment is in process, the wafer boat loaded with wafers in the furnace rotates driven by magnetic fluid, allowing the wafers on the wafer boat to be more fully in contact with the process gas. However, since vertical diffusion equipment is still in the development stage, there is still a lot of room for improvement in uniformity between wafers and production capacity. How to balance production capacity and uniformity between wafers has become a problem that needs to be solved urgently.

[0004] The process control technology of related vertical diffusion equipment is that during the diffusion process, the magnetic fluid maintains a uniform rotation during the process, and the reaction gas at a constant flow rate is continuously introduced into the air inlet. The end of the process is controlled according to the process duration. The reaction status of the chip cannot be obtained. The process duration is usually determined by manual experience. The accuracy of process time control is low, and it is difficult to improve the uniformity and production capacity between chips. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a process control method and semiconductor heat treatment equipment, which can more accurately grasp the process reaction time, improve the uniformity of process wafers, speed up the reaction progress, shorten the process reaction time, and increase production capacity.

[0006] In order to achieve the above purpose, the technical solution adopted by the embodiment of the present invention is as follows:

[0007] In the first aspect, an embodiment of the present invention provides a process control method applied to semiconductor heat treatment equipment, the process control method comprising: during the process, monitoring the wafer quality in the semiconductor heat treatment equipment, and calculating the rate of change of the wafer quality; when the rate of change is not zero, controlling the magnetic fluid rotation speed, air intake rate and exhaust rate of the semiconductor heat treatment equipment based on the rate of change until the rate of change is zero; wherein the magnetic fluid rotation speed, air intake rate and exhaust rate are all positively correlated with the rate of change.

[0008] Further, an embodiment of the present invention provides a first possible implementation of the first aspect, wherein the magnetic fluid rotation speed of the semiconductor heat treatment equipment is controlled based on the change rate, including: obtaining a plurality of preset rate thresholds, and determining the corresponding magnetic fluid rotation speed based on the relationship between the change rate and each of the rate thresholds; wherein different magnetic fluid rotation speeds correspond to different rate threshold intervals when the change rate is in different rate threshold intervals.

[0009] Further, an embodiment of the present invention provides a second possible implementation of the first aspect, wherein the intake rate and the exhaust rate of the semiconductor heat treatment equipment are controlled based on the change rate, including: controlling the intake rate and the exhaust rate based on the rotation speed of the magnetic fluid; wherein the intake rate and the exhaust rate are positively correlated with the rotation speed of the magnetic fluid; or, controlling the intake rate based on the rotation speed of the magnetic fluid, and determining the exhaust rate corresponding to the reaction chamber pressure when the reaction chamber pressure remains unchanged based on the intake rate.

[0010] Further, an embodiment of the present invention provides a third possible implementation of the first aspect, wherein the determining of the corresponding exhaust rate when the pressure in the reaction chamber remains unchanged based on the intake rate comprises: calculating the pressure reduction per unit time of the reaction gas introduced into the semiconductor heat treatment equipment after the reaction, recorded as the first pressure; calculating the pressure increase of the gas generated per unit time after the reaction gas introduced into the semiconductor heat treatment equipment after the reaction, recorded as the second pressure; determining the amount of gas change per unit time after the reaction gas in the reaction chamber reacts based on the first pressure and the second pressure, and calculating the corresponding exhaust rate when the pressure in the reaction chamber remains unchanged based on the intake rate and the gas change.

[0011] Further, an embodiment of the present invention provides a fourth possible implementation of the first aspect, wherein the amount of gas change per unit time after the reaction gas in the reaction chamber reacts is determined based on the first pressure and the second pressure, and the corresponding exhaust rate when the reaction chamber pressure remains unchanged is calculated based on the intake rate and the gas change, including: obtaining the amount of gas change per unit time when the reaction chamber pressure remains unchanged based on the relationship between the first pressure and the second pressure and the gas volume; when the consumed volume of the reaction gas is greater than the volume of the generated gas, the gas change is a gas reduction, and the corresponding exhaust rate when the reaction chamber pressure remains unchanged is calculated based on the intake rate and the gas reduction; when the consumed volume of the reaction gas is less than the volume of the generated gas, the gas change is a gas increase, and the corresponding exhaust rate when the reaction chamber pressure remains unchanged is calculated based on the intake rate and the gas increase.

[0012] Further, the embodiment of the present invention provides a fifth possible implementation of the first aspect, wherein the calculation formula of the gas change amount is: △V2=(m2 / M2)RT2 / P1;

[0013] When the consumption volume of the reaction gas is greater than the volume of the generated gas, the calculation formula of the pumping rate is: V 泵 =V 进气 -△V2,

[0014] When the consumption volume of the reaction gas is less than the volume of the generated gas, the calculation formula of the pumping rate is: V 泵 =V 进气 +△V2;

[0015] Wherein, ΔV2 is the gas change per unit time, V 泵 is the pumping rate, V 进气 is the intake rate, m2 is the mass of the gas generated by the reaction, M2 is the molar mass of the gas generated by the reaction, R is the gas constant, T2 is the temperature of the gas generated by the reaction, and P1 is the first pressure.

[0016] Further, an embodiment of the present invention provides a sixth possible implementation of the first aspect, wherein the process control method also includes: when the change rate is zero, determining that the process reaction is completed, controlling the air intake rate of the semiconductor heat treatment equipment to zero, and controlling the magnetic fluid rotation speed to a first preset speed and continuing for a second preset time.

[0017] Further, an embodiment of the present invention provides a seventh possible implementation of the first aspect, wherein the process control method also includes: when the change rate is not zero, if a manual control instruction is received, receiving a speed instruction of the magnetic fluid of the semiconductor heat treatment equipment, determining the speed of the magnetic fluid based on the speed instruction, or controlling the speed of the magnetic fluid to a preset default speed; determining the intake rate and the exhaust rate based on the speed of the magnetic fluid; wherein the intake rate and the exhaust rate are positively correlated with the speed of the magnetic fluid.

[0018] In a second aspect, an embodiment of the present invention further provides a semiconductor heat treatment device, comprising: a mass sensor, a magnetic fluid, a motor, an air intake valve, an air pump and a controller;

[0019] The rotating mechanism of the magnetic fluid is connected to the motor through a belt, the air inlet valve is arranged at the air inlet of the semiconductor heat treatment equipment, and the air pump is arranged at the exhaust port of the semiconductor heat treatment equipment;

[0020] The quality sensor is used to measure the quality of the wafer in the semiconductor thermal processing equipment;

[0021] The motor is used to drive the magnetic fluid to rotate, so that the magnetic fluid drives the wafer to rotate;

[0022] The air intake valve is used to adjust the air intake rate of the semiconductor heat treatment equipment, and the air extraction pump is used to adjust the air extraction rate of the semiconductor heat treatment equipment;

[0023] The controller is used to execute the process control method described in any one of the first aspects.

[0024] Further, the embodiment of the present invention provides a first possible implementation of the second aspect, wherein the semiconductor heat treatment equipment further comprises: a reaction chamber, a box frame, a fixing plate and a supporting plate;

[0025] The magnetic fluid, the support plate, the mass sensor and the fixed plate are arranged in sequence below the reaction chamber, the magnetic fluid is arranged on the rotating platform of the support plate, one end of the fixed plate is fixedly connected to the box frame, and the mass sensor is arranged on the flat table of the fixed plate.

[0026] The embodiment of the present invention provides a process control method and semiconductor heat treatment equipment. By monitoring the change rate of wafer mass in a diffusion device, the reaction of the wafer in a reaction chamber can be indirectly observed. By adaptively adjusting the magnetic fluid rotation speed, air intake rate and exhaust rate according to the change rate of wafer mass, and setting a higher magnetic fluid rotation speed, air intake rate and exhaust rate when the change rate of wafer mass is large, the wafer rotation speed and the gas volume in the chamber are adjusted according to the reaction progress of the wafer. The process reaction time can be more accurately grasped, the wafer uniformity is improved, and the wafer and the reaction gas react fully. At the same time, the reaction progress is accelerated, the process reaction time is shortened, and the production capacity is improved.

[0027] Other features and advantages of the embodiments of the present invention will be described in the following description, or some features and advantages can be inferred or determined without doubt from the description, or can be learned by implementing the above-mentioned techniques of the embodiments of the present invention.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A schematic diagram of the structure of a related semiconductor heat treatment equipment is shown;

[0031] Figure 2 A schematic diagram of the structure of a semiconductor heat treatment device provided by an embodiment of the present invention is shown;

[0032] Figure 3 A flow chart of a process control method provided by an embodiment of the present invention is shown;

[0033] Figure 4 A diagram showing the relationship between wafer quality change and reaction time provided by an embodiment of the present invention is shown;

[0034] Figure 5a A schematic diagram of a controller communication structure provided by an embodiment of the present invention is shown;

[0035] Figure 5b Another controller communication structure diagram provided by an embodiment of the present invention is shown;

[0036] Figure 6 A graph showing the relationship between the rate of change of wafer quality and time provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be described below in conjunction with the drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0038] At present, semiconductor heat treatment equipment is in the development stage, and there is still much room for improvement in wafer-to-wafer uniformity and production capacity. How to balance production capacity and wafer-to-wafer uniformity has become an urgent problem to be solved. The key step that affects wafer-to-wafer uniformity is the source doping process. Under high temperature environment, the wafer reacts with the reaction gas, and the source in the reaction gas is displaced and enters the wafer for doping, thereby forming a PN junction inside the wafer. The quality of the reaction process directly affects the wafer uniformity.

[0039] See Figure 1The schematic structural diagram of the related semiconductor heat treatment equipment shown in the figure includes a motor 101, a process door 102, a magnetic fluid 103, a furnace body 104, a wafer boat 106, an air inlet 107, an exhaust port 108 and a belt 109, and a wafer 105 is placed on the wafer boat 106.

[0040] In the process control technology of related semiconductor heat treatment equipment, the reaction gas is usually introduced into the furnace body of the semiconductor heat treatment equipment in a bottom-up circular air intake manner. The gas diffuses downward after reaching the top. A magnetic fluid is installed at the bottom of the chamber. The magnetic fluid is connected to the motor through a belt and can rotate under the drive of the motor. The reaction gas in the chamber contacts and reacts with the wafers on the wafer boat. Driven by the magnetic fluid, the wafer boat rotates at a uniform speed to accelerate the flow and diffusion of the gas, so that the wafer and the reaction gas react more fully. The reaction waste gas is discharged from the chamber through the exhaust hole until the process reaction time is reached, the magnetic fluid stops rotating, and the reaction gas is stopped from being filled.

[0041] The process control technology of related semiconductor heat treatment equipment still has the following disadvantages:

[0042] 1. Whether the process is completed is mainly determined by the process duration. The magnetic fluid keeps rotating at a constant speed during the process, and the reaction gas is continuously introduced into the air inlet. The reaction status of the wafer cannot be known, and it is difficult to master the process control link;

[0043] 2. During the entire diffusion process, the motor always drives the magnetic fluid to rotate at a constant speed. However, in the early stage of the process, a faster magnetic fluid speed is required. When the magnetic fluid speed is slow, the reaction gas diffuses slowly from the edge of the wafer to the center of the wafer, which easily leads to inadequate reaction. At the same time, it is also easy to cause the exhaust gas in the center of the wafer to be discharged slowly, which interferes with the concentration of the reaction gas and the process reaction.

[0044] 3. During the entire diffusion process, the reaction gas is continuously introduced at a uniform speed and the waste gas is continuously discharged at a uniform speed. However, in the middle stage after the reaction, the amount of reaction gas required is reduced, which easily causes waste of reaction gas and unreacted gas is easily discharged from the chamber, resulting in waste of resources;

[0045] 4. The process reaction time of the diffusion process is usually determined by manual experience and has low accuracy.

[0046] In order to improve the above problems, an embodiment of the present invention provides a process control method and semiconductor heat treatment equipment, and the embodiment of the present invention is introduced in detail below.

[0047] This embodiment provides a semiconductor thermal processing device, see Figure 2The semiconductor heat treatment equipment shown in the figure is a structural schematic diagram, which includes: a mass sensor 210, a magnetic fluid 205, a motor 207, an air intake valve (not shown in the figure), an air pump (not shown in the figure) and a controller (not shown in the figure).

[0048] The rotating mechanism of the magnetic fluid 205 is connected to the motor 207 through a belt 208, the air inlet valve is arranged at the air inlet 201 of the semiconductor heat treatment equipment, and the air pump is arranged at the exhaust port 213 of the semiconductor heat treatment equipment;

[0049] The quality sensor 210 is used to measure the quality of the wafer in the semiconductor thermal processing equipment;

[0050] The motor 207 is used to drive the magnetic fluid 205 to rotate, so that the magnetic fluid 205 drives the wafer 203 to rotate;

[0051] The above-mentioned air intake valve is used to adjust the air intake rate of the semiconductor heat treatment equipment, and the air pump is used to adjust the air extraction rate of the semiconductor heat treatment equipment; the controller is used to execute the process control method provided in the following embodiment.

[0052] The mass sensor 210 is also used to transmit the wafer mass to the controller in real time. The controller controls the rotation speed of the motor 207 according to the rate of change of the wafer mass, thereby controlling the rotation speed of the magnetic fluid. The controller also controls the intake rate of the intake valve and the exhaust rate of the exhaust pump according to the rate of change of the wafer mass.

[0053] In one embodiment, Figure 2 As shown, the semiconductor heat treatment equipment provided in this embodiment further includes: a reaction chamber 204, a box frame 212, a fixing plate 211 and a support plate 209. A magnetic fluid 205, a support plate 209, a quality sensor 210 and a fixing plate 211 are sequentially arranged below the reaction chamber 204, the magnetic fluid 205 is arranged on the rotating platform of the support plate 209, one end of the fixing plate 211 is fixedly connected to the box frame 212, and the quality sensor 210 is arranged on the flat table of the fixing plate 211.

[0054] In one embodiment, Figure 2 As shown, the semiconductor heat treatment equipment provided in this embodiment further includes: a wafer boat 202, a process door 206 and a belt 208. When the motor 207 rotates, the motor 207 drives the magnetic fluid 205 to rotate through the belt 208, thereby driving the wafer 203 to rotate.

[0055] The above-mentioned inlet valve is located at the inlet port 201 directly above the reaction chamber 204, and is used to introduce the reaction gas. The exhaust pump is located at the exhaust port 213 on the upper side of the reaction chamber 204, and can exhaust the reaction waste gas. Figure 2As shown, a wafer boat 202 is placed in the chamber, a wafer 203 is placed on the wafer boat 202, the wafer 203 reacts with the reaction gas in the chamber, and a magnetic fluid 205 is provided on the furnace door of the reaction chamber.

[0056] This embodiment provides a process control method, which is applied to the controller of the semiconductor heat treatment equipment provided in the above embodiment. Figure 3 The process control method flow chart shown in the figure comprises the following steps:

[0057] Step S302, during the process, monitoring the wafer quality in the semiconductor thermal processing equipment and calculating the rate of change of the wafer quality.

[0058] During the diffusion process of the semiconductor heat treatment equipment, the magnetic fluid runs at the initially set rotation speed, and the air intake rate and the air extraction rate are carried out at the initially set rates. The wafer quality detected by the quality sensor in real time is obtained, and the change rate of the wafer quality is calculated in real time or periodically.

[0059] If at time T1, the detected wafer quality is M T1 At time T2, the detected wafer quality is M T2 , then the rate of change of the wafer mass V 变 =(M T2 -M T1 ) / (T2-T1), the time interval t2 between time T1 and time T2 can be determined according to the required process duration, and the value range of the time interval t2 can be 1 to 2 minutes.

[0060] Step S304, when the change rate is not zero, controlling the magnetic fluid rotation speed, air intake rate and air extraction rate of the semiconductor heat treatment equipment based on the change rate until the change rate is zero.

[0061] See Figure 4 The relationship between the wafer quality change and the reaction time is shown in the figure. Taking the boron diffusion process of the wafer as an example, the trend of the SiO2 oxide layer changing with time during the process is as follows Figure 4 As shown, in the initial stage of the reaction, the contact area between the reaction gas and the wafer is large and the reaction speed is fast, so sufficient reaction gas must be ensured for the reaction. In the later stage of the reaction, as the SiO2 oxide layer increases and adheres to the wafer, the contact area between the reaction gas and the wafer becomes smaller. The thicker the oxide layer, the more difficult it is for the reaction gas to enter the surface of the wafer. At this time, the rotation rate and air intake rate of the wafer can be reduced, and the reaction can be waited for to stop.

[0062] In addition, according to Figure 4 It can be seen that in the diffusion process, as the process time increases, the chip quality gradually tends to be stable. Therefore, when the change rate of the chip quality is 0, it indicates that the reaction has stopped; when the change rate of the chip quality is not 0, it indicates that the reaction is not completed.

[0063] The above-mentioned magnetic fluid rotation speed, air intake rate and air extraction rate are all positively correlated with the change rate of the wafer mass. That is, when the change rate of the wafer mass increases, the magnetic fluid rotation speed, air intake rate and air extraction rate increase; when the change rate of the wafer mass decreases, the magnetic fluid rotation speed, air intake rate and air extraction rate decrease.

[0064] When the change rate of the wafer mass is large, it indicates that the reaction rate is fast, and when the change rate of the wafer mass is small, it indicates that the reaction rate is slow. When the process reaction rate in the reaction chamber is fast, by controlling the motor speed to increase, the diffusion of the reaction gas from the edge to the center can be accelerated, so that the reaction gas and the wafer react more fully, and at the same time, the intake rate and the exhaust rate are controlled to speed up to ensure that the reaction gas is sufficient and the generated waste gas is discharged from the chamber faster; when the process reaction rate in the chamber is slow, by controlling the motor speed to decrease, and at the same time controlling the intake rate and the exhaust rate to slow down, the gas in the chamber is sufficient for the wafer to react, and the reaction gas that does not react fully will be discharged with the waste gas, so there is no need to fill too much reaction gas, achieving the purpose of energy saving and emission reduction.

[0065] The controller in the semiconductor heat treatment equipment is directly or indirectly connected to the quality sensor and the motor. The controller can be a host computer or a slave computer, such as a programmable logic controller (PLC). Figure 5a A controller communication structure diagram is shown, the controller is respectively connected to the intake valve and the air pump for communication. When the controller is a PLC, the controller can communicate directly with the mass sensor and the servo driver of the motor; see Figure 5b Another controller communication structure diagram is shown. When the above-mentioned controller is a host computer or other slave computers except PLC, the controller communicates indirectly with the quality sensor and the servo driver of the motor through PLC. The quality sensor detects the chip quality and transmits it to PLC, and PLC transmits the chip quality to the controller.

[0066] The above-mentioned intake valve can be a flow meter capable of controlling the flow rate, or a valve capable of controlling the flow rate and a flow meter capable of detecting the flow rate. The controller converts the calculated intake rate into an intake valve opening or an intake valve flow rate according to the intake valve model, and sends the intake valve opening or intake valve flow rate to the intake valve to control the intake rate; the controller converts the exhaust rate into an exhaust pump speed according to the exhaust pump model to control the exhaust rate (i.e., the exhaust rate).

[0067] When the above-mentioned controller is a PLC, the controller controls the servo driver of the motor based on the rotation speed of the magnetic fluid, and the servo driver further controls the motor rotation speed. The magnetic fluid rotates along with the motor under the action of the belt; when the above-mentioned controller is a host computer or other slave computers except PLC, the controller transmits the motor speed instruction to the PLC, controls the servo driver through the PLC, and the servo driver further controls the motor rotation speed. The magnetic fluid rotates along with the motor under the action of the belt. In this process, the motor operation parameters detected by the servo driver are transmitted back to the controller through the PLC.

[0068] The process control method provided in this embodiment can indirectly observe the reaction of the wafer in the reaction chamber by monitoring the rate of change of the wafer mass in the diffusion equipment. The magnetic fluid rotation speed, air intake rate and exhaust rate are adaptively adjusted according to the rate of change of the wafer mass, and a higher magnetic fluid rotation speed, air intake rate and exhaust rate are set when the rate of change of the wafer mass is large. The wafer rotation speed and the amount of gas in the chamber are adjusted according to the reaction progress of the wafer. The process reaction time can be more accurately grasped, the uniformity of the wafer in the diffusion process is improved, and the sufficient reaction of the wafer and the reaction gas is ensured. At the same time, the reaction progress is accelerated, the process reaction time is shortened, and the production capacity is improved.

[0069] In one embodiment, this embodiment provides a specific implementation method for controlling the rotation speed of a magnetic fluid in a semiconductor heat treatment device based on a change rate:

[0070] Obtain multiple preset rate thresholds, and determine the corresponding magnetic fluid speed based on the magnitude relationship between the change rate and each rate threshold; wherein the change rate V 变 Different speed threshold intervals correspond to different magnetic fluid rotation speeds.

[0071] When in automatic control mode, set multiple change rate thresholds including V 阈1 ~V 阈n (n>1), when 0<V 变 ≤V 阈1 and the duration is greater than t 阈 When the magnetic fluid speed is controlled to be V 电c1 , that is, the speed of the motor connected to the magnetic fluid is controlled to be V 电c1 ;

[0072] When V 阈1 <V 变 ≤V 阈2 and the duration is greater than t 阈 When the magnetic fluid speed is controlled to be V 电c2 , that is, the speed of the motor connected to the magnetic fluid is controlled to be V 电c2 ;

[0073] …, and so on,

[0074] When V 阈n-1 <V 变 ≤V 阈n and the duration is greater than t 阈 When the magnetic fluid speed is controlled to be V 电cn , that is, the speed of the motor connected to the magnetic fluid is controlled to be V 电cn ; Among them, V 电c1 <V 电c2 <…<V 电cn By setting the duration threshold t 阈 , in order to prevent the instantaneous change in the rate of change of chip quality from affecting the judgment of the process, and improve the accuracy of process control.

[0075] In one embodiment, this embodiment provides two implementation methods for controlling the gas intake rate and gas extraction rate of semiconductor thermal processing equipment based on the change rate, which can be specifically implemented with reference to the following implementation methods 1 and 2:

[0076] Implementation method 1: controlling the air intake rate and the air extraction rate based on the magnetic fluid rotation speed;

[0077] The air intake rate and the air extraction rate are positively correlated with the magnetic fluid rotation speed. The greater the magnetic fluid rotation speed, the greater the air intake rate and the air extraction rate.

[0078] When 0<V 变 ≤V 阈1 and the duration is greater than t 阈 When the magnetic fluid speed is V 电c1 , control the intake rate of the intake valve to be V 气c1 , the pumping rate of the pump (i.e. the speed of the pump) is V 泵c1 ; and V 气c1 =V 泵c1 So that the air intake rate is equal to the air extraction rate;

[0079] When V 阈1 <V 变 ≤V 阈2 and the duration is greater than t 阈 When the magnetic fluid speed is V 电c2 , control the intake rate of the intake valve to be V 气c2 , the pumping rate of the pump (i.e. the speed of the pump) is V 泵c2 ; and V 气c2 =V 泵c2 So that the air intake rate is equal to the air extraction rate;

[0080] …, and so on,

[0081] When V 阈n-1 <V 变 ≤V 阈n and the duration is greater than t阈 When the magnetic fluid speed is V 电cn , control the intake rate of the intake valve to be V 气cn , the pumping rate of the pump (i.e. the speed of the pump) is V 泵cn ; and V 气cn =V 泵cn ; Among them, V 气c1 <V 气c2 <…<V 气cn .

[0082] Embodiment 2: The air intake rate is controlled based on the rotation speed of the magnetic fluid, and the corresponding air extraction rate is determined based on the air intake rate when the pressure of the reaction chamber remains unchanged.

[0083] Taking into account that the pressure stability in the chamber will affect the time it takes for the process to reach stability, and that in the actual reaction process, there will be a decrease in reaction gas and an increase in generated gas, the gas reaction will cause pressure changes, and the pressure in the chamber will be affected and reduced. In order to accurately achieve pressure stability in the chamber, when the intake rate is constant, the pumping rate can be adjusted according to the pressure difference before and after the gas reaction to keep the reaction chamber pressure stable. Alternatively, when the pumping rate is constant, the intake rate can be adjusted according to the pressure difference before and after the gas reaction to keep the reaction chamber pressure stable.

[0084] Considering that the gas intake rate of the reaction chamber is usually a set rate, this embodiment provides an implementation method for determining the corresponding gas extraction rate when the pressure of the reaction chamber remains unchanged based on the gas intake rate, which can be specifically performed with reference to the following steps:

[0085] Step 1): Calculate the pressure reduction per unit time of the reaction gas introduced into the semiconductor heat treatment equipment after the reaction, and record it as the first pressure.

[0086] The relationship between pressure and volume satisfies the Clapeyron equation: PV=(m / M)RT; P is the pressure of the gas, V is the volume of the gas, m is the mass of the gas, M is the molar mass of the gas, (m / M) is the number of moles, R is the universal constant of the gas, R=8.31J / mol, and T is the temperature of the gas.

[0087] The calculation formula for the first pressure P1 reduced by the reaction of the reaction gas introduced into the semiconductor heat treatment equipment is: P1 = (m1 / M1)RT1; m1 is the mass of the reaction gas, M1 is the molar mass of the reaction gas, (m1 / M1) is the number of moles of the reaction gas, and T1 is the temperature of the reaction gas.

[0088] Step 2): Calculate the increased pressure of the gas generated per unit time after the reaction gas introduced into the semiconductor heat treatment equipment reacts, and record it as the second pressure.

[0089] The calculation formula for the second pressure P2 of the gas generated per unit time after the reaction gas reacts is: P2 = (m2 / M2)RT2; wherein m2 is the mass of the gas generated by the reaction, M2 is the molar mass of the gas generated by the reaction, (m2 / M2) is the number of moles of the gas generated by the reaction, and T2 is the temperature of the gas generated by the reaction.

[0090] Step 3): determining the gas change per unit time after the reaction gas in the reaction chamber reacts based on the first pressure and the second pressure, and calculating the corresponding exhaust rate when the reaction chamber pressure remains unchanged based on the intake rate and the gas change.

[0091] Based on the relationship between the first pressure, the second pressure and the gas volume, the gas change per unit time when the pressure of the reaction chamber remains unchanged is obtained;

[0092] If the pressure in the reaction chamber is to be stable, the inlet volume must be equal to the outlet volume. However, in the actual reaction process, the reduction in the amount of reaction gas and the increase in the amount of generated gas may be different. Let the pressure change caused by the reaction be △P 变 , △P 变 =P1-P2, if the pressure in the reaction chamber is to be stable, △P 变 =0.

[0093] The calculation formula for the gas change (i.e. the gas increase or gas decrease after the reaction gas reacts) is: △V2 = (m2 / M2)RT2 / P1;

[0094] When the volume of the reaction gas consumed is greater than the volume of the generated gas, the gas change is the gas reduction amount, and the corresponding pumping rate when the reaction chamber pressure remains unchanged is calculated based on the gas intake rate and the gas reduction amount;

[0095] When the volume of the reaction gas consumed is greater than the volume of the generated gas, the volume of the gas in the chamber decreases after the reaction. It is necessary to reduce the pumping rate of the exhaust port to stabilize the pressure in the reaction chamber. The calculation formula for the pumping rate is: V 泵 =V 进气 -△V2; when the unit of the pumping rate is L / min, the above unit time is per minute; when the unit of the pumping rate is L / S, the above unit time is per second.

[0096] When the consumption volume of the reaction gas is less than the volume of the generated gas, the gas change amount is the gas increase amount, and the corresponding exhaust rate when the reaction chamber pressure remains unchanged is calculated based on the intake rate and the gas increase amount.

[0097] When the volume of the reaction gas consumed is less than the volume of the generated gas, the gas volume in the chamber increases after the reaction, and the pumping rate of the exhaust port needs to be increased to stabilize the pressure in the reaction chamber. The calculation formula for the pumping rate is: V 泵 =V 进气 +△V2.

[0098] Among them, △V2 is the gas change per unit time, V 泵 is the pumping rate, V 进气 is the intake rate, m2 is the mass of the gas generated by the reaction, M2 is the molar mass of the gas generated by the reaction, R is the gas constant, and T2 is the temperature of the gas generated by the reaction.

[0099] In one embodiment, the method provided in this embodiment also includes: when the change rate is zero, determining that the diffusion process reaction is completed, controlling the air intake rate of the semiconductor heat treatment equipment to zero, and controlling the magnetic fluid rotation speed to a first preset speed and continuing for a second preset time.

[0100] When the wafer mass does not change within a certain period of time, it indicates that the reaction is complete, and the introduction of the reaction gas should be stopped at this time. That is, when it is detected that the rate of change of the wafer mass is continuously zero within a preset time, it indicates that the reaction is complete, and the air intake rate of the semiconductor heat treatment equipment is controlled to be zero, that is, the air intake valve of the semiconductor heat treatment equipment is controlled to be closed to stop the introduction of the reaction gas into the reaction chamber; the magnetic fluid speed is controlled to be the first preset speed and lasts for the second preset time, that is, the motor is controlled to drive the magnetic fluid to rotate at the first preset speed for a certain period of time to discharge the exhaust gas in the reaction chamber so as to proceed to the next process step. The value range of the above-mentioned second preset time can be 1 to 5 minutes, and the preferred value is 2 minutes.

[0101] In one embodiment, in order to improve the control convenience of semiconductor heat treatment equipment, the method provided in this embodiment also includes: when the change rate is not zero, if a manual control instruction is received, receiving the speed instruction of the magnetic fluid of the semiconductor heat treatment equipment, determining the speed of the magnetic fluid based on the speed instruction, or controlling the speed of the magnetic fluid to a preset default speed; determining the intake rate and the exhaust rate based on the speed of the magnetic fluid; wherein the intake rate and the exhaust rate are positively correlated with the speed of the magnetic fluid.

[0102] The motor control method of the semiconductor heat treatment equipment provided in this embodiment may include two modes: manual control and automatic control. When the rate of change of the wafer quality is not zero, that is, when the reaction is not completed, if a manual control instruction input by the user is received, a speed instruction of the magnetic fluid input by the user is received, and the speed instruction of the magnetic fluid includes the speed value of the motor, and the motor corresponding to the magnetic fluid is controlled to rotate at the speed value; if the speed instruction of the magnetic fluid input by the user is not received after the manual control instruction input by the user is received, the motor corresponding to the magnetic fluid is controlled to rotate at a preset default speed, and the preset default speed is the default speed value of the motor, and the default speed value can be set manually. The air intake rate and the air extraction rate of the reaction chamber are controlled according to the speed instruction of the magnetic fluid input by the user or the preset default speed, and the valve opening of the air intake valve and the speed of the air extraction pump are positively correlated with the speed of the motor.

[0103] In one embodiment, before monitoring the quality of wafers in a semiconductor heat treatment device, the method provided in this embodiment also includes: when the process starts, controlling the magnetic fluid to rotate at a second preset speed for a third preset time; after the magnetic fluid rotates at the second preset speed for the third preset time, triggering the air intake valve of the semiconductor heat treatment device to open to start introducing reaction gas into the semiconductor heat treatment device.

[0104] The second preset speed may be the same as or different from the first preset speed. The third preset time may range from 1 to 3 minutes, with a preferred value of 1 minute.

[0105] When the process starts, the controller sends an instruction to control the motor of the magnetic fluid to rotate at the second preset speed for a certain period of time, and then triggers the gas enable signal to start introducing the reaction gas into the reaction chamber. After the gas is introduced, the motor still rotates at the second preset speed. The intake rate of the intake valve and the speed of the vacuum pump are related to the speed of the motor. By controlling the rotation of the magnetic fluid for a period of time at the beginning of the process, it is ensured that the gas flow in the chamber is uniform before the reaction gas is introduced, so that the reaction effect can be improved after the reaction gas is introduced.

[0106] The process control method provided in this embodiment can more accurately grasp the reaction of the wafer in the chamber by monitoring the rate of change of the wafer quality, and can observe and analyze the process more intuitively, so as to accurately control the magnetic fluid rotation speed and the intake valve intake rate. The magnetic fluid rotation speed is combined with the chamber pressure to jointly control the exhaust rate, which can improve the process stability, shorten the process reaction stabilization time, and thus shorten the process reaction time, improve the production capacity, and make the whole process more reasonable and efficient; by increasing the magnetic fluid rotation speed and the intake rate when the reaction speed is fast in the early stage of the reaction, it can ensure that the wafer and the reaction gas react fully, prevent the insufficient reaction product from being doped into the wafer, and affect the subsequent process, and at the same time, increase the exhaust rate to speed up the exhaust gas discharge from the chamber, prevent the excessive exhaust gas from interfering with the concentration of the reaction gas and interfering with the process reaction; by reducing the magnetic fluid rotation speed, the intake rate and the exhaust rate when the reaction rate is low in the middle and late stages of the reaction, it can prevent the unreacted gas from being discharged from the chamber under the premise of ensuring the reaction is sufficient, avoid the waste of reaction gas, and achieve energy saving and emission reduction; through the joint control of multiple parameters, it can effectively shorten the process reaction stabilization time, shorten the process time, and improve the production capacity within the same time, thereby improving the accuracy of process control.

[0107] Based on the above embodiment, this embodiment provides an example of a control method for improving the process uniformity of semiconductor thermal processing equipment by applying the above process control method, which can be specifically performed with reference to the following steps:

[0108] Step 1, when the process starts, the controller sends a command, and the motor connected to the magnetic fluid rotates at an initial speed V1 and maintains t1 time (t1 = 1min), which can ensure that the gas in the chamber flows evenly before the reaction gas is introduced, and the reaction effect is better after the reaction gas is introduced.

[0109] This embodiment takes the boron diffusion process as an example. The gaseous BCl3 diffusion source reacts with the wafer at a high temperature of 1050°C, causing the boron source to diffuse into the wafer to form a PN junction. The chemical reaction occurring during the process is:

[0110] 4BCl3+3O2→2B2O3+6Cl2

[0111] 2B2O3+3Si→3SiO2+4B

[0112] The reaction product Cl2 is discharged with the tail gas, SiO2 and B remain on the surface of the wafer. The furnace tube contains 4000-5000 wafers. The reaction products will cause changes in the wafer quality. According to the change in wafer quality and combined with the process time, the process reaction situation can be judged more accurately, which is convenient for operators to judge and analyze.

[0113] Step 2: After the motor rotates at the initial speed V1 for t1 time, the high-precision mass sensor is used to measure the initial mass M1 of the wafer and record it. At this time, the gas enable signal is triggered, and the motor still rotates at the initial speed V1. The air intake rate of the flow meter at the air inlet is controlled by the motor speed. The initial value of the air intake rate is V 气1 The initial speed of the exhaust pump at the exhaust port is V 泵1 . V 气1 and V 泵1 It is proportional to the initial speed V1 of the motor.

[0114] The above-mentioned flow meter is a sensor that can control the size of the intake air flow rate and detect the intake air flow rate value.

[0115] Step 3: The high-precision quality sensor transmits the wafer quality data to the PLC in real time, and then the PLC transmits it to the controller. The controller calculates the wafer quality change. If the wafer quality detected at time T1 is M T1 At time T2, the detected wafer quality is M T2 , then the rate of change of the wafer mass V 变 =(M T2 -M T1 ) / (T2-T1).

[0116] Step 4: When V is detected within the preset time period 变 =0, the flow meter at the control air inlet is closed, the reaction gas is stopped from entering the reaction chamber, and the motor is controlled to rotate at a speed of V1 for a time of t3 to discharge the exhaust gas in the chamber so as to proceed to the next process step.

[0117] Step 5, if V 变 ≠0, the magnetic fluid speed is controlled by motor speed control, which includes manual control mode and automatic control mode:

[0118] Manual control mode:

[0119] The motor speed is set with a default speed V 默 When there is no human intervention, the motor runs at the default speed V 默 Rotation. When the motor speed is modified by human intervention, the motor is controlled to rotate according to the speed input by the user. The controller adjusts the air intake rate of the flow meter and the air extraction rate of the air pump according to the motor speed. The air intake rate of the flow meter and the air extraction rate of the air extraction pump are proportional to the motor speed.

[0120] Automatic control mode:

[0121] Multiple change rate thresholds V can be set in automatic control mode 阈1 ~V 阈n (n>1);

[0122] When 0<V 变 ≤V 阈1 and the duration is greater than t 阈 When the controller sends the control instruction C1 to control the motor to rotate, the motor speed is V 电c1 , the air intake rate and air extraction rate of the flow meter are related to the motor speed, and the air intake rate of the flow meter is controlled to be V 气c1 ;

[0123] When V 阈1 <V 变 ≤V 阈2 and the duration is greater than t 阈 When the controller sends the control instruction C2 to control the motor to rotate, the motor speed is V 电c2 The intake rate and exhaust rate are related to the motor speed. The intake rate of the intake valve is controlled to be V 气c2 ;

[0124] When V 阈n-1 <V 变 ≤V 阈n and the duration is greater than t 阈 When the controller sends the control instruction Cn to control the motor to rotate, the motor speed is V 电cn The intake rate and exhaust rate are related to the motor speed. The intake rate of the intake valve is controlled to be V 气cn ;

[0125] The suction rate of the vacuum pump is equal to the intake rate of the flow meter, that is, V 气c1 =V 泵c1 , V 气c2 =V 泵c2 , V 气cn =V 泵cn ;

[0126] By changing the wafer mass rate V 变 It takes a long time to achieve a balance between the three variables and the stability of the process by simultaneously regulating the motor rotation speed, air intake rate and exhaust rate. In the actual production process, the process time is also a key parameter that determines the process quality. The longer the process time, the longer the process cycle, the lower the chip output, and the lower the profit. Therefore, for further optimization, this scheme adopts a scheme of step-by-step control of multiple variables to shorten the reaction time to achieve process stability.

[0127] Considering that the pressure stability in the chamber will also affect the time it takes for the process to reach stability, if the pressure in the chamber is to be stable, the air intake volume must be equal to the air output volume, that is, V 进气 =V 出气 However, in the actual reaction process, there will be a decrease in the reaction gas and an increase in the generated gas. For example, in the boron diffusion process, the volume of BCL3 consumed is greater than the volume of Cl2 generated. The pressure change caused by the reaction is △P 变, the pressure in the chamber is affected and becomes smaller. Therefore, if the pressure in the chamber is to be stable, it is necessary to make △P 变 = 0. The relationship between pressure and volume satisfies the Clapeyron equation: PV = (m / M)RT; P is the pressure of the gas, V is the volume of the gas, m is the mass of the gas, M is the molar mass of the gas, (m / M) is the number of moles, R is the universal constant of the gas, R = 8.31 J / mol, and T is the temperature of the gas.

[0128] BCL3 reaction causes a reduction in pressure: P BCL3 =(m BCL3 / M BCL3 )R BCL3 T BCL3 / V BCL3 ;

[0129] The increased pressure caused by the CL2 reaction is: P CL2 =(m CL2 / M CL2 )R CL2 T CL2 / V CL2 ;

[0130] △P 变 =P BCL3 -P CL2 ;

[0131] Air intake per unit time V BCL3 The air volume V per unit time can be obtained by monitoring the air intake flow meter. CL2 It can be obtained by monitoring the outlet flow meter (the outlet flow meter can only detect the flow value but not regulate the flow).

[0132] To achieve stable pressure in the chamber, △P 变 =0, then △V CL2 =(m CL2 / M CL2 )R CL2 T CL2 / P BCL3 , the optimal gas output of the vacuum pump can be calculated (the gas output per unit time is the vacuum rate). Since the volume of BCL3 consumed is greater than the volume of CL2 generated, V 泵 =V 进气 -△V CL2 , V 进气 The speed of the vacuum pump is the air intake volume per unit time at the air inlet. The speed of the vacuum pump is adjusted in real time according to the calculated vacuum pump pumping rate to achieve stable pressure in the chamber. In addition, the change of the magnetic fluid speed also affects the air intake volume at the air inlet. The speed of the vacuum pump is jointly controlled by the speed of the magnetic fluid motor and the air intake volume, which can achieve process stability in a relatively short time.

[0133] When the process reaction rate in the chamber is fast, the motor speed is fast, which accelerates the diffusion of the reaction gas from the edge to the center and reacts more fully with the chip. At the same time, the flow meter air intake rate is accelerated, and the air pump speed is also accelerated under the joint regulation of the motor speed and the chamber pressure to ensure that the reaction gas is sufficient and the generated waste gas is discharged from the chamber faster; when the process reaction rate in the chamber is slow, the motor speed is slow, and at the same time, the flow meter air intake rate slows down, and the air pump speed is also slowed down under the joint regulation of the motor speed and the chamber pressure. At this time, the gas in the chamber is sufficient for the chip to react, and the reaction gas that does not react fully will be discharged with the waste gas. There is no need to fill too much reaction gas, thereby achieving the purpose of energy saving and emission reduction.

[0134] Illustratively, this embodiment provides three groups of comparative experiments for process control of the above-mentioned semiconductor heat treatment equipment using the above-mentioned process control method. By placing a high-precision quality sensor on the machine, the change in chip quality is observed to evaluate the stability of the process reaction, and by performing a uniformity test on the chip, the uniformity of the chip is evaluated.

[0135] Experiment 1: During the process, the magnetic fluid speed is controlled to be constant, and the air inlet rate and the air outlet rate are also constant. This experiment cannot automatically adjust the reaction progress. The optimal reaction time is set according to experience. After reaching the preset time, the reaction results are observed.

[0136] Experiment 2: During the process, the magnetic fluid speed is affected by the change of wafer quality. The change rate of wafer quality V 变 =(M T2 -M T1 ) / (T2-T1).

[0137] Set multiple change rate thresholds V 阈1 ~V 阈n (n>1); For example, setting V 阈1 =0.1g / min, V 阈2 =0.2g / min, and so on, each threshold increases by 0.1g / min compared to the previous threshold, and the time threshold tthreshold is set to =30s.

[0138] When 0<V 变 ≤V 阈1 and the duration is greater than t 阈 When the controller sends the control instruction C1 to control the motor to rotate, the motor speed is V 电c1 , the air intake rate and air extraction rate of the flow meter are positively correlated with the motor speed. The air intake rate of the flow meter is controlled to be V 气c1 ; Control the suction rate of the vacuum pump to be equal to the intake rate V 气c1 =V 泵c1 ;

[0139] When V 阈1 <V变 ≤V 阈2 and the duration is greater than t 阈 When the controller sends the control instruction C2 to control the motor to rotate, the motor speed is V 电c2 The intake rate and exhaust rate are positively correlated with the motor speed. The intake rate of the intake valve is controlled to be V 气c2 ; Control the suction rate of the vacuum pump to be equal to the intake rate V 气c2 =V 泵c2 ;

[0140] When V 阈n-1 <V 变 ≤V 阈n and the duration is greater than t 阈 When the controller sends the control instruction Cn to control the motor to rotate, the motor speed is V 电cn The intake rate and exhaust rate are positively correlated with the motor speed. The intake rate of the intake valve is controlled to be V 气cn ; Control the suction rate of the vacuum pump to be equal to the intake rate V 气cn =V 泵cn ;

[0141] The air intake rate and air extraction rate are positively correlated with the motor speed, that is, the larger the motor speed, the larger the corresponding air intake rate and air extraction rate. 电c1 <V 电c2 <…<V 电cn , then the intake rate satisfies V 气c1 <V 气c2 <…<V 气cn , the pumping rate satisfies V 泵c1 <V 泵c2 <…<V 泵cn ;

[0142] When the chip mass does not change within 1 minute, the reaction is stopped and the reaction results are observed.

[0143] Experiment 3: During the process, the magnetic fluid speed is affected by the change of wafer quality. The change rate of wafer quality V 变 =(M T2 -M T1 ) / (T2-T1).

[0144] Set multiple change rate thresholds V 阈1 ~V 阈n (n>1); For example, setting V 阈1 =0.1g / min, V 阈2 =0.2g / min, and so on, each threshold increases by 0.1g / min compared to the previous threshold, and the time threshold tthreshold is set to =30s.

[0145] When 0<V变 ≤V 阈1 and the duration is greater than t 阈 When the controller sends the control instruction C1 to control the motor to rotate, the motor speed is V 电c1 , the air intake rate of the flow meter is positively correlated with the motor speed, and the air intake rate of the flow meter is controlled to be V 进气c1 ; The pumping rate of the vacuum pump is jointly controlled according to the motor speed and chamber pressure

[0146] When V 阈1 <V 变 ≤V 阈2 and the duration is greater than t 阈 When the controller sends the control instruction C2 to control the motor to rotate, the motor speed is V 电c2 The air intake rate is positively correlated with the motor speed, and the air intake rate of the air intake valve is controlled to be V 进气c2 ; The pumping rate of the vacuum pump is jointly controlled according to the motor speed and chamber pressure

[0147] When V 阈n-1 <V 变 ≤V 阈n and the duration is greater than t 阈 When the controller sends the control instruction Cn to control the motor to rotate, the motor speed is V 电cn The air intake rate is positively correlated with the motor speed, and the air intake rate of the air intake valve is controlled to be V 进气cn ; The pumping rate of the vacuum pump is jointly controlled according to the motor speed and chamber pressure

[0148] The air intake rate is positively correlated with the motor speed, that is, the greater the motor speed, the greater the corresponding air intake rate. 电c1 <V 电c2 <…<V 电cn , then the intake rate satisfies V 气c1 <V 气c2 <…<V 气cn ;

[0149] When the chip mass does not change within 1 minute, the reaction is stopped and the reaction results are observed.

[0150] See the three sets of experimental results and wafer uniformity table shown in Table 1 below, and Figure 6 The relationship between the wafer quality change rate and time of the three groups of experiments shown in the figure, wherein curve 1 is the curve corresponding to experiment one, curve 2 is the curve corresponding to experiment two, and curve 3 is the curve corresponding to experiment three.

[0151] Table 1 Three groups of experimental results and wafer uniformity list

[0152] Chip 1 square resistance Chip 2 square resistance Chip 3 square resistance Inter-chip uniformity Experiment 1 138 155 162 7.9％ Experiment 2 142 151 155 4.3％ Experiment 3 145 150 154 3.0％

[0153] According to the above table 1 and Figure 6 The experimental results show that the process control method provided by Experiment 3 achieves the best inter-wafer uniformity effect, and the curve is relatively gentle. The process control process of Experiment 3 completes the reaction first, and the time is shortened by about 15%. This is because Experiment 1 uses a conventional air intake control method, the magnetic fluid speed is constant, the air intake rate and the air outlet rate are also constant, and the reaction progress cannot be automatically adjusted; Experiment 2 uses a single variable "wafer quality change rate V 变 "The motor speed, air intake rate and air outlet rate are adjusted at the same time. The balance of the three variables needs to be achieved to stabilize the process reaction. In addition, Experiment 2 did not consider the impact of chamber pressure changes on the experiment, and the control accuracy of the pumping rate was lower than that of Experiment 3. Experiment 3 adopted a multi-variable step-by-step control method. The motor speed was first controlled by the wafer mass change rate, and the air intake rate was then controlled by the motor speed. At the same time, the pumping rate (i.e., the pumping pump speed) was controlled by the motor speed combined with the chamber pressure change. Not only the impact of the wafer mass change rate on the process was considered, but also the impact of the chamber pressure change on the process was considered, which improved the control accuracy and experimental stability, and shortened the time required to achieve process reaction stability. The experimental results show that the process control method provided in Experiment 3 in this embodiment can effectively improve the reaction stability and wafer uniformity, and can effectively shorten the reaction time, thereby increasing the production capacity within the same time.

[0154] An embodiment of the present invention provides a computer-readable medium, wherein the computer-readable medium stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement the method described in the above embodiment.

[0155] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system described above can refer to the corresponding process in the aforementioned embodiment, and will not be repeated here.

[0156] In addition, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0157] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0158] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0159] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A process control method, characterized in that: Applied to semiconductor heat treatment equipment, the process control method includes: During the process, monitoring the quality of the wafer in the semiconductor thermal processing equipment and calculating the rate of change of the wafer quality; When the change rate is not zero, the magnetic fluid rotation speed, air intake rate and exhaust rate of the semiconductor heat treatment equipment are controlled based on the change rate until the change rate is zero; wherein the magnetic fluid rotation speed, air intake rate and exhaust rate are all positively correlated with the change rate.

2. The method according to claim 1, characterized in that The method of controlling the magnetic fluid rotation speed of the semiconductor heat treatment equipment based on the change rate includes: Acquire multiple preset rate thresholds, and determine the corresponding magnetic fluid rotation speed based on the magnitude relationship between the change rate and each of the rate thresholds; wherein, different magnetic fluid rotation speeds correspond to different rate threshold intervals when the change rate is in different rate threshold intervals.

3. The method according to claim 2, characterized in that Controlling the gas intake rate and gas extraction rate of the semiconductor thermal processing equipment based on the change rate includes: The air intake rate and the air extraction rate are controlled based on the rotation speed of the magnetic fluid; wherein the air intake rate and the air extraction rate are positively correlated with the rotation speed of the magnetic fluid; or, The air intake rate is controlled based on the rotation speed of the magnetic fluid, and the corresponding air extraction rate when the pressure of the reaction chamber remains unchanged is determined based on the air intake rate.

4. The method according to claim 3, characterized in that The step of determining a corresponding exhaust rate when the pressure of the reaction chamber remains unchanged based on the intake rate includes: Calculate the pressure of the reaction gas introduced into the semiconductor heat treatment equipment that decreases per unit time after the reaction, and record it as the first pressure; Calculate the increased pressure of the gas generated per unit time after the reaction gas introduced into the semiconductor heat treatment equipment reacts, and record it as the second pressure; The gas change per unit time of the reaction gas in the reaction chamber after the reaction is determined based on the first pressure and the second pressure, and the corresponding exhaust rate when the pressure of the reaction chamber remains unchanged is calculated based on the intake rate and the gas change.

5. The method according to claim 4, characterized in that The determining of the gas change amount per unit time of the reaction gas in the reaction chamber after the reaction based on the first pressure and the second pressure, and calculating the corresponding exhaust rate when the pressure of the reaction chamber remains unchanged based on the intake rate and the gas change amount, include: Obtaining the gas change per unit time when the pressure of the reaction chamber remains unchanged based on a relationship between the first pressure, the second pressure and the gas volume; When the consumption volume of the reaction gas is greater than the volume of the generated gas, the gas change amount is the gas reduction amount, and the corresponding gas extraction rate when the pressure of the reaction chamber remains unchanged is calculated based on the gas intake rate and the gas reduction amount; When the consumption volume of the reaction gas is less than the volume of the generated gas, the gas change amount is the gas increase amount, and the corresponding exhaust rate when the pressure of the reaction chamber remains unchanged is calculated based on the intake rate and the gas increase amount.

6. The method according to claim 5, characterized in that The calculation formula of the gas change is: △V2 = (m2 / M2)RT2 / P1; When the consumption volume of the reaction gas is greater than the volume of the generated gas, the calculation formula of the pumping rate is: V 泵 =V 进气 -△V2, When the consumption volume of the reaction gas is less than the volume of the generated gas, the calculation formula of the pumping rate is: V 泵 =V 进气 +△V2; Wherein, ΔV2 is the gas change per unit time, V 泵 is the pumping rate, V 进气 is the intake rate, m2 is the mass of the gas generated by the reaction, M2 is the molar mass of the gas generated by the reaction, R is the gas constant, T2 is the temperature of the gas generated by the reaction, and P1 is the first pressure.

7. The method according to claim 1, characterized in that Also includes: When the change rate is zero, it is determined that the process reaction is completed, the air intake rate of the semiconductor heat treatment equipment is controlled to be zero, and the rotation speed of the magnetic fluid is controlled to be a first preset speed and last for a second preset time.

8. The method according to claim 1, characterized in that: Also includes: When the rate of change is not zero, if a manual control instruction is received, a speed instruction of the magnetic fluid of the semiconductor heat treatment equipment is received, and the speed of the magnetic fluid is determined based on the speed instruction, or the speed of the magnetic fluid is controlled to be a preset default speed; The air intake rate and the air extraction rate are determined based on the rotation speed of the magnetic fluid; wherein the air intake rate and the air extraction rate are positively correlated with the rotation speed of the magnetic fluid.

9. A semiconductor heat treatment device, characterized in that: include: Mass sensor, magnetic fluid, motor, air inlet valve, air pump and controller; The rotating mechanism of the magnetic fluid is connected to the motor through a belt, the air inlet valve is arranged at the air inlet of the semiconductor heat treatment equipment, and the air pump is arranged at the exhaust port of the semiconductor heat treatment equipment; The quality sensor is used to measure the quality of the wafer in the semiconductor thermal processing equipment; The motor is used to drive the magnetic fluid to rotate, so that the magnetic fluid drives the wafer to rotate; The air intake valve is used to adjust the air intake rate of the semiconductor heat treatment equipment, and the air extraction pump is used to adjust the air extraction rate of the semiconductor heat treatment equipment; The controller is used to execute the process control method described in any one of claims 1-8.

10. The semiconductor heat treatment equipment according to claim 9, characterized in that: Also includes: Reaction chamber, box frame, fixing plate and supporting plate; The magnetic fluid, the support plate, the mass sensor and the fixed plate are arranged in sequence below the reaction chamber, the magnetic fluid is arranged on the rotating platform of the support plate, one end of the fixed plate is fixedly connected to the box frame, and the mass sensor is arranged on the flat table of the fixed plate.

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