Control method for a protective gas circuit

Abstract

The present disclosure provides a method for controlling a protective gas path to introduce a protective gas into a wafer loading device, the protective gas path comprising an inlet flow path, an exhaust flow path, and a vacuum flow path, the inlet flow path being provided with an inlet valve and a mass flow controller, the exhaust flow path being provided with an exhaust valve and a sensor, comprising: opening the inlet valve so that the protective gas reaches an upstream side of the mass flow controller; determining a preset ambient atmosphere parameter representing a preset ambient atmosphere according to a wafer process; determining a flow parameter of the mass flow controller according to the preset ambient atmosphere parameter and an ambient atmosphere forming path library; opening the exhaust valve; opening the mass flow controller and simultaneously opening the vacuum flow path, so that the protective gas flows into a wafer chamber through the inlet flow path, and the gas in the wafer chamber is exhausted through the exhaust flow path; in response to the ambient atmosphere parameter in the current wafer chamber satisfying the preset ambient atmosphere parameter, cutting off the mass flow controller; cutting off the inlet valve and simultaneously cutting off the vacuum flow path; cutting off the exhaust valve.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a control method for a protective gas path suitable for providing a suitable ambient atmosphere to a wafer cavity. Background Technology

[0002] In semiconductor manufacturing, wafers undergo multiple front-end processes, including oxide deposition, photolithography, etching, ion implantation, and cleaning, followed by multiple back-end processes such as thinning, dicing, bonding, and packaging. When wafers leave the process room and are temporarily stored in wafer loading equipment, they need to be placed in a specific environmental atmosphere for protection or post-processing. Therefore, in actual production, it is desirable to create or maintain an environmental atmosphere with required properties such as pressure, temperature, and humidity for a certain period of time.

[0003] Traditional technologies typically employ fixed flow rates combined with simple timing control, or real-time sensor feedback to control the timing and flow rate of the protective gas. However, for protective gases of different types and purities, it is difficult to easily obtain the mapping relationship between the timing and flow rate of the protective gas and the temperature and / or humidity of the ambient atmosphere. This makes traditional control methods reliant on the operator's experience to set relevant parameters, and it is also difficult to ensure the quality of the generated ambient atmosphere.

[0004] Furthermore, traditional control methods rarely consider the impact of wafer processing on the ambient atmosphere. This results in longer processing times or larger quantities of protective gas needed to create the required atmosphere, unnecessarily increasing the cost of the ambient atmosphere. Additionally, there is currently no control method that dynamically adjusts the flow parameters of the protective gas path to create the desired ambient atmosphere using fewer resources. Summary of the Invention

[0005] In view of this, the present disclosure provides a control method for a protective gas path suitable for providing a suitable ambient atmosphere to a wafer cavity, aiming to solve the above-mentioned technical problems. This control method is applicable to controlling the protective gas path to introduce protective gas into the wafer cavity. The protective gas path includes an inlet gas path, an exhaust gas path, and a vacuum gas path. The inlet gas path is equipped with an inlet valve and a mass flow controller, and the exhaust gas path is equipped with an exhaust valve and a sensor. The control method includes:

[0006] Open the intake valve to allow the protective gas to reach the upstream side of the mass flow controller;

[0007] Based on the wafer process, determine the preset ambient atmosphere parameters that characterize the preset ambient atmosphere;

[0008] Based on the preset ambient atmosphere parameters and the ambient atmosphere formation path library, the flow parameters of the mass flow controller are determined;

[0009] Open the exhaust valve;

[0010] opening the mass flow controller and simultaneously opening the vacuum flow path, so that the protective gas flows into the wafer chamber through the gas inlet flow path, and the gas in the wafer chamber is discharged through the exhaust flow path;

[0011] in response to the current environmental atmosphere parameter in the wafer chamber meeting the preset environmental atmosphere parameter, cutting off the mass flow controller;

[0012] cutting off the gas inlet valve and simultaneously cutting off the vacuum flow path; and

[0013] cutting off the exhaust valve.

[0014] The control method of the protective gas path provided by the present disclosure can be applied to protective gas paths with the same or similar structure, to plan the implementation path of the environmental atmosphere in the wafer chamber according to the process experienced by the wafer, generate the flow parameter directly applied to the mass flow controller, and control the cutting off of the protective gas path according to the environmental atmosphere parameter in the wafer chamber, so that the experimenter can obtain the environmental atmosphere of the wafer chamber in accordance with the expectations without determining the relationship between the flow parameter of the protective gas and the environmental atmosphere parameter. The control method thus arranged can also take into account the influence of the process experienced by the wafer on the formation of the environmental atmosphere, so as to plan to obtain the environmental atmosphere of the wafer chamber in accordance with the expectations within a specified time and a limited amount of protective gas according to the actual production situation of semiconductors. BRIEF DESCRIPTION OF DRAWINGS

[0015] It should be understood that the following drawings only show certain embodiments of the present disclosure and should not be considered as limiting the scope.

[0016] It should be understood that the same or similar reference signs are used to represent the same or similar elements in the drawings.

[0017] It should be understood that the elements in the drawings are only schematic and the size and proportions of the elements in the drawings are not necessarily precise.

[0018] Figure 1 is a structural schematic view of an exemplary wafer carrying device provided by the present disclosure.

[0019] Figure 2 is a structural schematic view of the wafer box in Figure 1 from another perspective.

[0020] Figure 3 is a sectional view of the wafer loading device in Figure 1 along the A-A sectional line.

[0021] Figure 4 is a gas path schematic diagram of an exemplary protective gas path of the present disclosure.

[0022] Figure 5is a structural schematic diagram of an exemplary protective atmosphere path of the present disclosure, in which some components are omitted.

[0023] Figure 6 is a flow chart of a control method of an exemplary protective atmosphere path applicable to the present disclosure.

[0024] Figure 7 is another flow chart of a control method of a protective atmosphere path of the present disclosure.

[0025] Figure 8 is another flow chart of a control method of a protective atmosphere path of the present disclosure.

[0026] Figure 9 is another flow chart of a control method of a protective atmosphere path of the present disclosure.

[0027] In which the components of the protective atmosphere path are identified as follows:

[0028] wafer loading device 1; protective atmosphere path 10; intake flow path 10A; intake valve 101; mass flow controller 102; solenoid valve 101a; diaphragm solenoid valve 101b; pressure reducing valve 101c; digital pressure sensor 103; auxiliary filter 109; wafer cassette 20; carrier 21; base 22; cassette body 23; wafer cavity 201; intake hole 221; exhaust hole 222; exhaust flow path 10B; exhaust valve 104; first solenoid valve 104a; filter 105; sensor 106; temperature and humidity sensor 106a; flow sensor 106b; vacuum flow path 10C; vacuum generator 108; wafer 30. DETAILED DESCRIPTION

[0029] Numerous specific details are set forth in the following description in order to provide a thorough understanding of the structure, function and use of the embodiments described and shown in the specification. It will be appreciated that the embodiments described and shown are non-limiting examples, and that the particular structural and functional details disclosed herein are representative and exemplary. Variations and changes can be made to these embodiments without departing from the scope of the claims.

[0030] <Exemplary protective atmosphere path>

[0031] For ease of understanding, reference is made to Figures 1 to 3 The present disclosure first shows a wafer loading device 1. The wafer loading device 1 is configured to carry multiple wafers 30 between multiple wafer processing procedures. A protective atmosphere path 10 is installed in the wafer loading device 1, which is suitable for providing a suitable environmental atmosphere to the wafers 30. Other devices that need to form an environmental atmosphere in a relatively closed space can also apply the protective atmosphere path 10 described below based on the same or similar principles.

[0032] The wafer loading apparatus 1 can include a wafer cassette 20. By way of example only, the wafer cassette 20 can include a base 22 and a body 23. A carrier 21 is contained in a wafer cavity 201 formed between the base 22 and the body 23 and is adapted to support a plurality of wafers 30. The base 22 and the body 23 are capable of being driven to move relatively. When the base 22 and the body 23 are moved relatively apart, the wafer cavity 201 is capable of communicating with the external environment to receive the plurality of wafers 30 from the outside and / or to take out the plurality of wafers 30 from the wafer cassette 20. When the base 22 and the body 23 are moved relatively close, the wafer cavity 201 does not communicate with the external environment and the plurality of wafers are supported in the wafer cavity 201. As one possible implementation, the base 22 can include an air inlet hole 221 and an air outlet hole 222 arranged diagonally along the base 22.

[0033] With reference to Figure 4 and Figure 5 The protective gas path 10 can include an air inlet flow path 10A. One end of the air inlet flow path 10A communicates with the protective gas source to obtain the protective gas from the protective gas source. The other end of the air inlet flow path 10A communicates with the air inlet hole 221 to enable the protective gas to flow into the wafer cavity 201. The air inlet flow path 10A is provided with an air inlet valve 101 and a mass flow controller 102. By way of example only, in the direction of the protective gas flowing into the wafer cavity 201, the air inlet valve 101 is located upstream of the mass flow controller 102, and the mass flow controller 102 is located upstream of the air inlet hole 221. The air inlet valve 101 can include one or more of a solenoid valve, a pressure reducing valve and / or a manual switch. Preferably, the air inlet valve 101 includes a solenoid valve 101a, a diaphragm solenoid valve 101b and a pressure reducing valve 101c. The solenoid valve 101a is capable of controlling the communication or blockage of the diaphragm solenoid valve 101b to avoid the flow of the protective gas impacting or corroding the air inlet valve 101. The pressure reducing valve 101c is capable of reducing the pressure of the protective gas from the protective gas source to enable the protective gas reaching the mass flow controller 102 to be easily stabilized. Optionally, a digital pressure sensor 103 can be provided downstream of the pressure reducing valve 101c to feedback the pressure parameter of the reduced pressure protective gas. The mass flow controller 102 can be a thermal type, a differential pressure type or a volumetric type mass flow controller. The mass flow controller 102 is capable of delivering the protective gas flowing at a constant flow rate downstream thereof and is capable of being controlled to change the constant flow rate at any time. The air inlet valve 101 and the mass flow controller 102 are capable of being controlled to communicate and / or block, respectively. When the air inlet valve 101 and the mass flow controller 102 are both communicated, they allow the protective gas to reach the air inlet hole 221 at a constant flow rate and then flow into the wafer cavity 201. Optionally, an auxiliary filter 109 is provided downstream of the mass flow controller 102. The auxiliary filter 109 is capable of ensuring the quality of the protective gas flowing into the wafer cavity 201.

[0034] The protective gas path 10 can include an exhaust flow path 10B. One end of the exhaust flow path 10B is in communication with the exhaust hole 222 to allow the gas in the wafer chamber 201 (hereinafter referred to as mixed gas) to flow out of the wafer chamber 201. The other end of the exhaust flow path 10B is in communication with a collection container. An exhaust valve 104, a filter 105, and a sensor 106 are provided in the exhaust flow path 10B. By way of example only, in the direction of the mixed gas flowing out of the wafer chamber 201, the exhaust hole 222 is upstream of the filter 105, the filter 105 is upstream of the sensor 106, and the sensor 106 is upstream of the exhaust valve 104. Similarly, the exhaust valve 104 can be one or more of an electromagnetic valve, a pressure valve, and / or a manual switch. Preferably, the exhaust valve 104 includes a first electromagnetic valve 104a. The exhaust valve 104 can be controlled to communicate or block the exhaust flow path 10B, thereby allowing or limiting the exhaust of the mixed gas. The filter 105 can include a chemical gas filter and / or a particulate filter, which can reduce the content of components such as dust, fluoride, etc. in the mixed gas. This will make the detection result of the sensor 106 provided downstream more accurate, improve the service life of the sensor 106, and also make the post-processing of the mixed gas in the collection container easier. As one possible implementation, the sensor 106 can include only a temperature and humidity sensor 106a, or can include a temperature and humidity sensor 106a and a flow sensor 106b. By way of example only, in the direction of the mixed gas flowing out of the wafer chamber 201, the temperature and humidity sensor 106a is upstream of the flow sensor 106b. The sensor 106 can acquire parameters such as the temperature and humidity of the mixed gas to feedback the quality of the ambient atmosphere of the wafer chamber 201.

[0035] The protective gas path 10 can also include a vacuum flow path 10C. The vacuum flow path 10C is configured to provide negative pressure at the exhaust hole 222 to allow the mixed gas to flow out of the wafer chamber 201 smoothly. By way of example only, the vacuum flow path 10C can include a vacuum valve and a vacuum generator 108. The vacuum valve can be controlled to activate and / or block the vacuum generator 108 to allow or limit the vacuum flow path 10C to provide negative pressure at the exhaust hole 222. Preferably, the vacuum valve is an electromagnetic valve 101a, so that the intake flow path 10A and the vacuum flow path 10C can be controlled to be opened or blocked synchronously. By way of example only, the vacuum generator 108 can acquire a vacuum generating fluid different from the protective gas to suck out the mixed gas by the Venturi effect, i.e. to provide negative pressure to the wafer chamber 201. Preferably, CDA (clean dry air) can be used to provide negative pressure to the wafer chamber 201. The clean dry air can flow into the collection container together with the mixed gas through a part of the exhaust flow path 10B, specifically through the exhaust valve 104. Under the joint action of the properties of the clean dry air and the filter 105, the ambient atmosphere in the wafer chamber 201 is only affected by the ventilation time and flow of the protective gas, and can be accurately detected by the sensor 106.

[0036] The protective gas path 10 thus arranged is advantageous. The wafer chamber 201 can be used to receive wafers 30 subjected to various process treatments, which can have different surface conditions, temperatures and / or humidity, which will result in a large difference in the initial environment atmosphere formed in the wafer chamber 201. The exemplary protective gas path 10 thus arranged can ensure that the protective gas enters the wafer chamber 201 at a constant flow rate, and ensure that the mixed gas flows out under the action of negative pressure, and finally forms a required environment atmosphere. The quality of the environment atmosphere in the wafer chamber 201 can be fed back through the parameters of the sensor 106 arranged at the exhaust flow path 10B, especially the temperature, humidity and flow rate parameters. The filter 105 can avoid the interference of dust, particulate matter or residual reactants on the surface of the wafer 30 on the detection results of the sensor 106. The mixed atmosphere finally flows into the collection container to reduce environmental pollution.

[0037] <Control method of exemplary protective gas path>

[0038] Reference Figures 6 to 9 The present disclosure provides a control method suitable for the exemplary protective gas path 10, comprising:

[0039] opening the inlet valve 101 so that the protective gas reaches the upstream side of the mass flow controller 102;

[0040] determining a preset environment atmosphere parameter 200 for characterizing a preset environment atmosphere according to the wafer process 100;

[0041] determining the flow rate parameter 400 of the mass flow controller 102 according to the preset environment atmosphere parameter 200 and the environment atmosphere forming path library 300;

[0042] opening the exhaust valve 104;

[0043] opening the mass flow controller 102 and simultaneously opening the electromagnetic valve 101a, so that the protective gas flows into the wafer chamber 201 through the inlet flow path 10A, and the gas in the wafer chamber 201 is discharged through the exhaust flow path 10B;

[0044] in response to the environment atmosphere parameter 500 in the current wafer chamber 201 satisfying the preset environment atmosphere parameter 200, cutting off the mass flow controller 102;

[0045] cutting off the inlet valve 101 and simultaneously cutting off the electromagnetic valve 101a; and

[0046] cutting off the exhaust valve 104.

[0047] In the present disclosure, the term "ambient atmosphere" means the ambient fluid in a relatively closed container. When the relatively closed container is the wafer chamber 201, the ambient atmosphere means the ambient fluid in the wafer chamber 201 that surrounds the plurality of wafers 30.

[0048] In the present disclosure, the term "ambient atmosphere parameter" means the various parameters that the ambient atmosphere itself can have, such as pressure, temperature, humidity, etc. In a semiconductor manufacturing process, the wafers 30 will undergo a plurality of processes, and thus have different surface conditions, temperatures, and / or humidity. By placing the wafers 30 in an ambient atmosphere having specific ambient atmosphere parameters, it will help to ensure the quality of the wafers 30, improve the yield of semiconductor manufacturing, and allow the manufacturing of higher precision products.

[0049] In the present disclosure, the terms "preset ambient atmosphere" and "preset ambient atmosphere parameter" respectively mean the plurality of ambient atmospheres during the process of forming the desired ambient atmosphere from the ambient atmosphere where the wafers 30 are initially located after the wafers 30 are determined to undergo a certain wafer process, and the ambient atmosphere parameters corresponding to the plurality of ambient atmospheres. By way of example only, the surface of the wafers 30 after undergoing an etching process often has fluorides remaining thereon, which can undesirably corrode the wafers when the ambient atmosphere humidity is high, and thus it is desirable for the wafers 30 to eventually be in an ambient atmosphere having lower humidity. By way of example only, the surface of the wafers 30 after undergoing a thinning process can have dust thereon, and can release deformation energy due to mechanical stress, and when the ambient atmosphere temperature is high, the heat dissipation of the wafers 30 is inhibited and can thus cause undesired wafer warping, and thus it is desirable for the wafers 30 to eventually be in an ambient atmosphere having lower temperature.

[0050] In the present disclosure, the term "flow parameter" means the time-varying curve of the constant flow of the protective gas delivered by the mass flow controller 102. The mass flow controller 102 is capable of delivering the pressure-determined protective gas to the gas inlet hole 221 at a constant flow. When receiving instructions from the outside or being controlled by the control unit, the mass flow controller 102 is capable of delivering the pressure-determined protective gas at another constant flow.

[0051] In the present disclosure, the term "satisfy" means that the ambient atmosphere parameter 500 is within the range of 200 ± 5% of the preset ambient atmosphere parameter 200. Depending on the actual process, the range can be further adjusted.

[0052] In the present disclosure, the protective gas can be different kinds and purities of gas. Alternatively, the protective gas is an inert gas. Preferably, the protective gas is nitrogen.

[0053] Reference Figures 4 to 9 The method provided by the present embodiment will now be described in detail in combination with the structure of an exemplary protective gas path:

[0054] After determining the wafer 30 has undergone a wafer process 100, the inlet valve 101 is opened, and the protective gas from the protective gas source reaches the upstream side of the mass flow controller 102 at a determined pressure. At this time, the protective gas path 10 is not fully open. Subsequently, the wafer cassette 20 is driven to open to receive the plurality of wafers 30 from the external environment, and then the wafer cassette 20 is driven to close to store the plurality of wafers 30 in the wafer chamber 201. As the wafer 30 undergoes a process such as etching, thinning, etc., an environmental atmosphere associated with the wafer process 100 will quickly form in the relatively closed wafer chamber 201. By way of example only, when the wafer 30 undergoes a thinning process, it can have a higher temperature and a lower humidity, and will cause an environmental atmosphere with a higher temperature and a lower humidity to form in the wafer chamber 201. In one possible implementation, the environmental atmosphere parameters at this time can be obtained by detection during the execution of the wafer process 100. The environmental atmosphere parameters associated with the wafer process 100 are the starting point of the preset environmental atmosphere parameters 200. In one possible implementation, the preset environmental atmosphere parameters 200 thus include the starting point C1 of the temperature change curve, and / or the starting point C3 of the humidity change curve.

[0055] After determining the starting point of the preset environmental atmosphere parameters 200, the experimenter also needs to determine the ending point of the preset environmental atmosphere parameters 200. That is, the parameters of the environmental atmosphere that is expected to finally form in the wafer chamber 201 also need to be determined. The preset environmental atmosphere parameters 200 can thus also include the ending point C2 of the temperature change curve, and / or the ending point C4 of the humidity change curve. The ending point C2 will have a certain relationship with the starting point C1, and / or the ending point C4 will have a certain relationship with the starting point C2, so as to ensure the quality of the wafer 30. By way of example only, when the wafer 30 undergoes a thinning process, it can have a higher temperature and a lower humidity, so it is expected that an environmental atmosphere with an ending point C2 lower than the starting point C1 and an ending point C4 higher than the starting point C3 will form in the wafer chamber 201. This decrease or increase can be a proportional decrease or increase (by way of example only, C2 is decreased to 80% of C1), or a numerical decrease or increase (by way of example only, C2 is 5°C lower than C1). The relationship of the ending point of the environmental atmosphere parameters 200 to the starting point can be obtained by the experimenter according to experience, or can be adjusted according to the actual situation in the semiconductor manufacturing process.

[0056] The sensor 106 is provided in the exhaust flow path 10B of the example protective gas path 10, which enables the example protective gas path 10 to detect and form a plurality of flow parameter-environmental atmosphere parameter mapping curves. The plurality of flow parameter-environmental atmosphere parameter mapping curves collectively constitute the environmental atmosphere formation path library 300. By way of example only, the following will show a method of forming the environmental atmosphere formation path library 300:

[0057] The inlet valve 101 is opened;

[0058] acquiring the type of the protective gas, the gas flow of the mass flow controller 102, and the purging time of the mass flow controller 102;

[0059] opening the exhaust valve 104;

[0060] opening the mass flow controller 102 while opening the electromagnetic valve 101a;

[0061] obtaining a flow parameter-temperature mapping curve D1 and / or a flow parameter-humidity mapping curve D2 according to the sensor 106.

[0062] opening the inlet valve 101 to pre-purge the protective gas to the upstream of the mass flow controller 102. The type and flow parameter of the protective gas from the outside can be manually set by the experimenter or filtered by an algorithm. After determining the type and flow parameter of the protective gas, the mass flow controller 102 will be opened to the wafer chamber 201 at a first constant flow for a first period of time.

[0063] Subsequently, the exhaust valve 104 is opened to connect the exhaust flow path 10B, and the mixed gas and the vacuum gas can flow out of the protective flow path 10 through the exhaust valve 104.

[0064] Subsequently, the mass flow controller 102 is opened while the electromagnetic valve 101a is opened, so that the protective gas flows into the wafer chamber 201 at a first constant flow, and the mixed gas in the wafer chamber 201 is discharged under the action of negative pressure. Since the inlet hole 221 and the exhaust hole 222 are arranged along the diagonal line of the base 22, the risk of forming turbulent flow in the wafer chamber 201 is reduced, and the environmental atmosphere is stably changed.

[0065] Due to the arrangement of the filter 105, the change of the environmental atmosphere in the wafer chamber 201 can be approximately understood as the change of the mixed gas. The parameters of the mixed gas are detected and fed back by the sensor 106. The data obtained by the sensor 106 ultimately form a curve of the change of the temperature of the environmental atmosphere with time when a certain type of protective gas is purged at a constant flow Q, i.e. a flow parameter-temperature mapping curve D1. At the same time, a curve of the change of the humidity of the environmental atmosphere with time when a certain type of protective gas is purged at a constant flow Q can also be formed, i.e. a flow parameter-humidity mapping curve D2.

[0066] By repeating the above steps, a plurality of mapping curves of the flow parameter-environmental atmosphere parameter corresponding to different types of protective gas can be obtained. The set of the plurality of mapping curves of the flow parameter-environmental atmosphere parameter is the environmental atmosphere forming path library 300.

[0067] It should be noted that other possible devices and detection methods can also be used to obtain the ambient atmosphere forming path library 300, and the ambient atmosphere forming path library 300 can also be determined based on experience. However, using the example protective gas path 10 to obtain the ambient atmosphere forming path library 300 has the advantages that the influence of device differences on the reliability of the mapping curve can be excluded, and the formation of the ambient atmosphere and the formation of the ambient atmosphere forming path library 300 can be realized using the same device, simplifying the operation of the experimenter, and making the protective gas path 10 have a wider range of uses.

[0068] Preferably, the ambient atmosphere forming path library 300 forms a queryable temperature table and a humidity table. The column field of the temperature table is the type of protective gas, the row field of the temperature table is the constant flow Q, and the content stored in the table is the temperature curve of the protective gas changing with time. The column field of the humidity table is the type of protective gas, the row field of the humidity table is the constant flow Q, and the content stored in the table is the humidity curve of the protective gas changing with time. The table thus arranged facilitates data query, reduces the space required for data storage, and avoids unnecessary increase in cost caused by repeated experiments.

[0069] When the preset ambient atmosphere parameters 200 and the ambient atmosphere forming path library 300 are determined, the flow parameter 400 of the mass flow controller 102 can be determined by the following steps:

[0070] According to the starting point C1 and the ending point C2, a starting flow parameter-temperature mapping relationship curve D11 containing the starting point C1 and a target flow parameter-temperature mapping relationship curve D12 containing the ending point C2 are selected from the flow parameter-temperature mapping relationship curve D1;

[0071] In the case where the starting flow parameter-temperature mapping relationship curve D11 and the target flow parameter-temperature mapping relationship curve D12 have an intersection point C5, an ambient atmosphere forming path D3 including the starting point C1, the ending point C2 and the intersection point C5 is formed;

[0072] According to the gas flow Q3 and the ventilation time t3 of the ambient atmosphere forming path D3, the flow parameter 400 is determined.

[0073] When the preset ambient atmosphere parameter 200 includes a starting point C1 and an ending point C2, i.e., the temperature is the main factor of the ambient atmosphere affecting the wafer quality 30, the starting flow parameter-temperature mapping relationship curve D11 including the starting point C1 is obtained from the ambient atmosphere forming path library 300, and the target flow parameter-temperature mapping relationship curve D12 including the ending point C2 is obtained. When the starting flow parameter-temperature mapping relationship curve D11 and the target flow parameter-temperature mapping relationship curve D12 have an intersection point C5, the quality flow controller 102 is controlled to pass the protective gas at the gas flow Q11 corresponding to the starting flow parameter-temperature mapping relationship curve D11 for the ventilation time t11, and then the quality flow controller 102 is controlled to continue to pass the protective gas at the gas flow Q12 corresponding to the target flow parameter-temperature mapping relationship curve D12 for the ventilation time t12, so that the temperature of the ambient atmosphere changes from the starting point C1 to the ending point C2. At this time, the flow Q11 and Q12 are determined as the flow parameter Q3 of the quality flow controller 102, and the ventilation times t11 and t12 are determined as the ventilation time t3 of the quality flow controller 102. The flow parameter Q3 and the ventilation time t3 are the flow parameter 400. In this way, the experimenter does not need to rely on experience or repeatedly calculate the relationship between the ventilation time, the gas flow and the temperature of different kinds of protective gas, and the flow parameter 400 that can meet the preset ambient atmosphere parameter 200 can be obtained.

[0074] When the ambient atmosphere parameter 500 in the wafer chamber 201 meets the preset ambient atmosphere parameter 200, the quality flow controller 102 is cut off, i.e., the gas inlet flow path 10A is cut off. The quality flow controller 102 no longer passes the protective gas to the gas inlet hole 221.

[0075] It should be noted that the control method provided by the present disclosure uses at least one of the temperature, humidity and pressure of the mixed gas as the ambient atmosphere parameter 500 of the wafer chamber 201. The ambient atmosphere parameter 500 can be obtained in real time by the sensor 106. Although in the ideal state, the ambient atmosphere forming path D3 can help to obtain the ambient atmosphere with the ending point C2, due to the influence of the response time of the quality flow controller 102, the parameter fed back in real time by the sensor 106 is the parameter for stopping the quality flow controller, which can ensure that each flow path of the protective gas path 10 is unobstructed. At the same time, it is verified that the ambient atmosphere in the wafer chamber 201 meets the preset ambient atmosphere parameter 200.

[0076] Subsequently, the electromagnetic valve 101a and the intake valve 101 are simultaneously cut off, i.e., the vacuum flow path 10C is cut off and the intake flow path 10A is cut off from the protective gas source. No negative pressure is formed at the exhaust hole 222, and the protective gas no longer enters the intake flow path 10A. The protective gas trapped between the mass flow controller 102 and the intake hole 221 is sucked into the wafer chamber 201, while allowing part of the mixed gas to be discharged through the exhaust flow path 10B. This ensures that the air pressure in the wafer chamber 201 is stable. The protective gas is trapped between the protective gas source and the mass flow controller 102, and then flows out of the intake flow path 10A through methods such as pressure reduction recovery.

[0077] Subsequently, the exhaust valve 104 is cut off, i.e., the exhaust flow path 10B is cut off. The properties of the mixed gas in the wafer chamber 201 no longer change, and the environmental atmosphere tends to be stable.

[0078] On the basis of the above-mentioned control method, another method for determining the flow parameter 400 of the mass flow controller 102 is also provided, comprising:

[0079] According to the starting point C1 and the ending point C2, a plurality of starting flow parameter-temperature mapping relationship curves D11 containing the starting point C1 and a plurality of target flow parameter-temperature mapping relationship curves D12 containing the ending point C2 are selected from the flow parameter-temperature mapping relationship curve D1;

[0080] In the case where there is an intersection C5 between any one of the plurality of starting flow parameter-temperature mapping relationship curves D11 and any one of the plurality of target flow parameter-temperature mapping relationship curves D12, an environmental atmosphere forming path D3 including the starting point C1, the ending point C2 and the intersection C5 is formed;

[0081] When there are a plurality of environmental atmosphere forming paths D3, according to the resource consumption indicators of the plurality of environmental atmosphere forming paths D3, one of the plurality of environmental atmosphere forming paths D3 is determined as a dominant environmental atmosphere forming path D31;

[0082] According to the gas flow Q31 and the ventilation time t31 of the dominant environmental atmosphere forming path D31, the flow parameter 400 is determined.

[0083] Different from the above control method, when there are multiple environment atmosphere forming paths D3, the dominant environment atmosphere forming path D31 can be selected according to the consumption resource index. Specifically, when one environment atmosphere forming path D3 is determined, one flow parameter 400 can be obtained, including the gas flow Q3 and the ventilation time t3. For the wafer loading device 1 which needs to quickly form the expected environment atmosphere, it is suitable to select the environment atmosphere forming path D3 with smaller ventilation time as the dominant environment atmosphere forming path D31. For the wafer loading device 1 which needs to save cost, it is suitable to select the environment atmosphere forming path D3 with smaller total amount of protective gas as the dominant environment atmosphere forming path D31, and the total amount of protective gas can be obtained by integrating the gas flow and the ventilation time.

[0084] The preferred environment atmosphere forming path can also be selected by selecting other indexes, such as the change gradient of temperature and / or humidity, the maximum gas flow, etc., which will not be described here.

[0085] Based on the same or similar principles, the flow parameter 400 of the mass flow controller 102 can also be determined by the following steps:

[0086] According to the starting point C3 and the ending point C4, the starting flow parameter-humidity mapping relationship curve D21 containing the starting point C3 and the target flow parameter-humidity mapping relationship curve D22 containing the ending point C4 are selected from the flow parameter-humidity mapping relationship curve D2;

[0087] In the case that the starting flow parameter-humidity mapping relationship curve D21 and the target flow parameter-humidity mapping relationship curve D22 have an intersection point C6, the environment atmosphere forming path D4 including the starting point C3, the ending point C4 and the intersection point C6 is formed.

[0088] According to the gas flow Q4 and the ventilation time t4 of the environment atmosphere forming path D4, the flow parameter 400 is determined.

[0089] When the preset ambient atmosphere parameter 200 includes the starting point C3 and the ending point C4, i.e., the humidity is the main factor affecting the wafer quality 30, the starting flow parameter-humidity mapping relationship curve D21 including the starting point C3 is obtained from the ambient atmosphere forming path library 300, and the target flow parameter-humidity mapping relationship curve D22 including the ending point C4 is obtained. When the starting flow parameter-humidity mapping relationship curve D21 and the target flow parameter-humidity mapping relationship curve D22 have an intersection point C6, the quality flow controller 102 is controlled to pass the protective gas at the gas flow Q21 corresponding to the starting flow parameter-humidity mapping relationship curve D21 for the ventilation time t21, and then the quality flow controller 102 is controlled to continue to pass the protective gas at the gas flow Q22 corresponding to the target flow parameter-humidity mapping relationship curve D22 for the ventilation time t22, so that the humidity of the ambient atmosphere changes from the starting point C3 to the ending point C4. The flow Q21 and Q22 are determined as the flow parameter Q4 of the quality flow controller 102, and the ventilation times t21 and t22 are determined as the ventilation time t4 of the quality flow controller 102. The flow parameter Q4 and the ventilation time t4 are the flow parameter 400. In this way, the experimenter does not need to rely on experience or repeatedly calculate the relationship between the ventilation time, the gas flow and the temperature of different kinds of protective gas, and the flow parameter 400 expected to meet the preset ambient atmosphere parameter 200 can be obtained.

[0090] On the basis of the above control method, another method for determining the flow parameter 400 of the quality flow controller 102 is also provided, which includes:

[0091] According to the starting point C3 and the ending point C4, a plurality of starting flow parameter-humidity mapping relationship curves D21 containing the starting point C3 and a plurality of target flow parameter-humidity mapping relationship curves D22 containing the ending point C4 are selected from the flow parameter-humidity mapping relationship curve D2;

[0092] In the case that there is an intersection point C6 between any one of the plurality of starting flow parameter-humidity mapping relationship curves D21 and any one of the plurality of target flow parameter-humidity mapping relationship curves D22, an ambient atmosphere forming path D4 including the starting point C3, the ending point C4 and the intersection point C6 is formed;

[0093] When there are a plurality of ambient atmosphere forming paths D4, according to the resource consumption indicators of the plurality of ambient atmosphere forming paths D4, one of the plurality of ambient atmosphere forming paths D4 is determined as a dominant ambient atmosphere forming path D41;

[0094] According to the gas flow Q41 and the ventilation time t41 of the dominant ambient atmosphere forming path D41, the flow parameter 400 is determined.

[0095] The principle of the control method of the preset ambient atmosphere parameter 200 with temperature as the main influencing factor can be similarly applied to the control method of the preset ambient atmosphere parameter 200 with humidity as the main influencing factor, which will not be repeated here.

[0096] It should be noted that when the preset ambient atmosphere parameter 200 depends on both temperature and humidity, a series of starting curves including starting point C1 can be selected from the flow parameter-temperature mapping relationship curve D1 in combination, while the curve in the flow parameter-humidity mapping relationship curve D2 corresponding to the starting curve includes starting point C3; then, a series of target curves including end point C2 are selected from the flow parameter-temperature mapping relationship curve D1, while the humidity curve in the flow parameter-humidity mapping relationship curve D2 corresponding to the target curve includes end point C4; and ensure that there is intersection C5 between the corresponding temperature curves and intersection C6 between the corresponding humidity curves. The ambient atmosphere forming path formed in this way can be similarly applied to obtain the flow parameter 400.

[0097] In addition, the present disclosure also provides a control method when there is a large difference between the ambient atmosphere parameter 500 and the preset ambient atmosphere parameter 200, which is also applicable to the exemplary protective atmosphere path 10, and further comprises:

[0098] A temperature and humidity threshold range K is set, which includes a temperature upper threshold K1, a temperature lower threshold K2, a humidity upper threshold K3, and a humidity lower threshold K4;

[0099] When the ambient atmosphere parameter 500 exceeds any one of the temperature upper threshold K1, the temperature lower threshold K2, the humidity upper threshold K3, and the humidity lower threshold K4, the preset ambient atmosphere parameter 200 is re-determined according to the corresponding threshold.

[0100] The re-determination of the preset ambient atmosphere parameter 200 by the above control method comprises:

[0101] According to the corresponding threshold, the starting point C1 of the temperature change curve of the preset ambient atmosphere and / or the starting point C3 of the humidity change curve of the preset ambient atmosphere are determined.

[0102] The above control method further comprises: controlling the sensor 106 to monitor the ambient atmosphere parameter 500 in real time, and re-determining the preset ambient atmosphere parameter 200 according to the ambient atmosphere parameter 500 monitored in real time.

[0103] In the present disclosure, by way of example only, the term "exceeds" means that the ambient atmosphere parameter 500 is greater than the upper temperature threshold K1+10% of the upper temperature threshold K1, less than the lower temperature threshold K2-10% of the lower temperature threshold K2, greater than the upper humidity threshold K3+10% of the upper humidity threshold K3, or less than the lower humidity threshold K4-10% of the lower humidity threshold K4. Depending on the actual process, the specific threshold corresponding to the term "exceeds" can be further adjusted.

[0104] When the ambient atmosphere in the wafer chamber 201 also needs to be maintained within a certain temperature threshold, or within a certain humidity threshold, the determination of whether the upper temperature threshold K1 or the lower temperature threshold K2 needs to be used as the starting point C1 of the preset ambient atmosphere parameter 200 to re-determine the flow parameter 400 so that the ambient atmosphere 500 is lowered from the upper temperature threshold K1 to the preset end point C2 or raised from the lower temperature threshold K2 to the preset end point C2 can be made by comparing the temperature in the ambient atmosphere parameter 500 with the upper temperature threshold K1 or the lower temperature threshold K2. In this way, the corresponding curve in the ambient atmosphere forming path library 300 will be searched and determined again, and a more suitable flow parameter to form the required ambient atmosphere will be searched. Similarly, the determination of whether the upper humidity threshold K3 or the lower humidity threshold K4 needs to be used as the starting point C3 of the preset ambient atmosphere parameter 200 to make the ambient atmosphere 500 lower from the upper humidity threshold K3 to the preset end point C4 or raise from the lower humidity threshold K4 to the preset end point C4 can be made by comparing the humidity in the ambient atmosphere parameter 500 with the upper humidity threshold K3 or the lower humidity threshold K4. This will search and determine the corresponding curve in the ambient atmosphere forming path library 300 again, and search for a more suitable flow parameter to form the required ambient atmosphere. The control method comprising the above steps will make the intersection C5 or the intersection C6 far exceed the required ambient atmosphere parameter 500, and even possibly make the ambient atmosphere forming path when the quality of the wafer 30 is degraded not be used. The temperature of the mixed gas in the wafer chamber 201 is higher than the lower temperature threshold K2 and lower than the upper temperature threshold K1 in most cases, and / or the humidity of the mixed gas in the wafer chamber 201 is higher than the lower humidity threshold K4 and lower than the upper humidity threshold K3 in most cases. In this way, the quality of multiple wafers 30 can be ensured.

[0105] It should be noted that the various elements described in the above embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0106] It should be understood that multiple components and / or parts shown in the disclosed embodiments can be provided as single, integrated components / part. Alternatively, a single integrated component / part can be divided into separate multiple components and / or parts. A disclosure of "a" or "one" does not exclude more than one.

[0107] The above describes the basic principles of the present disclosure in combination with specific embodiments, but it should be noted that the advantages, benefits, effects and the like mentioned in the present disclosure are only examples and are not limiting, and these advantages, benefits, effects and the like cannot be considered as necessary for each embodiment of the present disclosure. In addition, the above specific details of the disclosure are only for the purpose of example and for the purpose of understanding, and are not limiting, and the above details do not limit the present disclosure to be necessarily implemented with the above specific details.

[0108] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present disclosure, which should be covered by the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A control method suitable for controlling a shield gas path to introduce a shield gas into a wafer chamber, characterized by, The protection gas path comprises an air inlet flow path, an air outlet flow path and a vacuum flow path, the air inlet flow path is provided with an air inlet valve and a mass flow controller, the air outlet flow path is provided with an air outlet valve and a sensor, and the control method comprises: opening the air inlet valve to make the protection gas reach the upstream side of the mass flow controller; determining a preset ambient atmosphere parameter representing a preset ambient atmosphere according to a wafer process, wherein the preset ambient atmosphere represents a plurality of ambient atmospheres in a process of forming a desired ambient atmosphere from an initial ambient atmosphere for a wafer undergoing the wafer process; determining a flow parameter of the mass flow controller according to the preset ambient atmosphere parameter and an ambient atmosphere forming path library, wherein the ambient atmosphere forming path library is a set of a plurality of mapping curves of flow parameter-ambient atmosphere parameter; opening the air outlet valve; opening the mass flow controller and simultaneously opening the vacuum flow path to make the protection gas flow into the wafer chamber through the air inlet flow path and make the gas in the wafer chamber flow out through the air outlet flow path; cutting off the mass flow controller in response to the current ambient atmosphere parameter in the wafer chamber meeting the preset ambient atmosphere parameter; cutting off the air inlet valve and simultaneously cutting off the vacuum flow path; and cutting off the air outlet valve.

2. The control method according to claim 1, characterized by, The determining of the preset ambient atmosphere parameter according to the wafer process comprises: determining a starting point and an ending point of a temperature change curve of the preset ambient atmosphere according to the wafer process, and / or: determining a starting point and an ending point of a humidity change curve of the preset ambient atmosphere according to the wafer process.

3. The control method according to claim 2, characterized by, The determining of the preset ambient atmosphere parameter according to the wafer process comprises: in a case where the wafer process is a thinning process, determining the ending point of the temperature change curve of the preset ambient atmosphere to be lower than the starting point of the temperature change curve of the preset ambient atmosphere, and determining the ending point of the humidity change curve of the preset ambient atmosphere to be higher than the starting point of the humidity change curve of the preset ambient atmosphere.

4. The control method according to claim 2, characterized by, The determining of the preset ambient atmosphere parameter according to the wafer process comprises: in a case where the wafer process is an etching process, determining the ending point of the humidity change curve of the preset ambient atmosphere to be lower than the starting point of the humidity change curve of the preset ambient atmosphere.

5. The control method according to claim 2, characterized by, The ambient atmosphere forming path library comprises a plurality of flow parameter-temperature mapping relationship curves of different kinds of protection gases and a plurality of flow parameter-humidity mapping relationship curves of different kinds of protection gases.

6. The control method according to claim 5, characterized by The flow parameter-temperature mapping relationship curve and / or the flow parameter-humidity mapping relationship curve are obtained by the following steps: opening the air inlet valve; obtaining the kind of the protection gas, the gas flow of the mass flow controller and the ventilation time of the mass flow controller; opening the air outlet valve; opening the mass flow controller and simultaneously opening the vacuum flow path; obtaining the flow parameter-temperature mapping relationship curve and / or the flow parameter-humidity mapping relationship curve according to the sensor.

7. The control method according to claim 5, characterized by, The determining of the flow parameter of the mass flow controller comprises: selecting, according to the start point and the end point of the temperature change curve of the preset environmental atmosphere, a starting flow parameter-temperature mapping relationship curve containing the start point of the temperature change curve of the preset environmental atmosphere and a target flow parameter-temperature mapping relationship curve containing the end point of the temperature change curve of the preset environmental atmosphere from the flow parameter-temperature mapping relationship curve; in a case where there is an intersection between the starting flow parameter-temperature mapping relationship curve and the target flow parameter-temperature mapping relationship curve, forming an environmental atmosphere forming path including the start point of the temperature change curve of the preset environmental atmosphere, the end point of the temperature change curve of the preset environmental atmosphere and the intersection; determining the flow parameter according to the gas flow and the ventilation time of the environmental atmosphere forming path.

8. The control method according to claim 5, characterized by, The determining the flow parameter of the mass flow controller comprises: selecting, according to the start point and the end point of the temperature change curve of the preset environmental atmosphere, a starting flow parameter-temperature mapping relationship curve containing the start point of the temperature change curve of the preset environmental atmosphere and a target flow parameter-temperature mapping relationship curve containing the end point of the temperature change curve of the preset environmental atmosphere from the flow parameter-temperature mapping relationship curve; in a case where there is an intersection between the starting flow parameter-temperature mapping relationship curve and the target flow parameter-temperature mapping relationship curve, forming an environmental atmosphere forming path including the start point of the temperature change curve of the preset environmental atmosphere, the end point of the temperature change curve of the preset environmental atmosphere and the intersection; when there are multiple environmental atmosphere forming paths, determining one of the multiple environmental atmosphere forming paths as a dominant environmental atmosphere forming path according to resource consumption indexes of the multiple environmental atmosphere forming paths; determining the flow parameter according to the gas flow and the ventilation time of the dominant environmental atmosphere forming path.

9. The control method according to claim 5, characterized by, The determining the flow parameter of the mass flow controller comprises: selecting, according to the start point and the end point of the temperature change curve of the preset environmental atmosphere, a starting flow parameter-temperature mapping relationship curve containing the start point of the temperature change curve of the preset environmental atmosphere and a target flow parameter-temperature mapping relationship curve containing the end point of the temperature change curve of the preset environmental atmosphere from the flow parameter-temperature mapping relationship curve; in a case where there is an intersection between the starting flow parameter-temperature mapping relationship curve and the target flow parameter-temperature mapping relationship curve, forming an environmental atmosphere forming path including the start point of the temperature change curve of the preset environmental atmosphere, the end point of the temperature change curve of the preset environmental atmosphere and the intersection; determining the flow parameter according to the gas flow and the ventilation time of the environmental atmosphere forming path.

10. The control method according to claim 5, characterized by, The determining the flow parameter of the mass flow controller comprises: selecting, according to the start point and the end point of the temperature change curve of the preset environmental atmosphere, a starting flow parameter-temperature mapping relationship curve containing the start point of the temperature change curve of the preset environmental atmosphere and a target flow parameter-temperature mapping relationship curve containing the end point of the temperature change curve of the preset environmental atmosphere from the flow parameter-temperature mapping relationship curve; in a case where there is an intersection between the starting flow parameter-temperature mapping relationship curve and the target flow parameter-temperature mapping relationship curve, forming an environmental atmosphere forming path including the start point of the temperature change curve of the preset environmental atmosphere, the end point of the temperature change curve of the preset environmental atmosphere and the intersection; determining the flow parameter according to the gas flow and the ventilation time of the environmental atmosphere forming path. According to the starting point and the ending point of the humidity change curve of the preset ambient atmosphere, a plurality of starting flow parameter-humidity mapping relationship curves containing the starting point of the humidity change curve of the preset ambient atmosphere and a plurality of target flow parameter-humidity mapping relationship curves containing the ending point of the humidity change curve of the preset ambient atmosphere are selected from the flow parameter-humidity mapping relationship curve; In the case that there is an intersection between any one of the plurality of starting flow parameter-humidity mapping relationship curves and any one of the plurality of target flow parameter-humidity mapping relationship curves, an ambient atmosphere forming path including the starting point of the humidity change curve of the preset ambient atmosphere, the ending point of the humidity change curve of the preset ambient atmosphere and the intersection is formed; When there are a plurality of the ambient atmosphere forming paths, according to the resource consumption indicators of the plurality of ambient atmosphere forming paths, one of the plurality of ambient atmosphere forming paths is determined as a dominant ambient atmosphere forming path; According to the gas flow and the ventilation time of the dominant ambient atmosphere forming path, the flow parameter is determined.

11. The control method according to claim 8 or 10, characterized by, The resource consumption indicators include total protective gas consumption and / or ventilation time.

12. The control method according to claim 11, characterized by, The determination of one of the plurality of ambient atmosphere forming paths as the dominant ambient atmosphere forming path includes: determining that one of the plurality of ambient atmosphere forming paths with the minimum total protective gas consumption as the dominant ambient atmosphere forming path, or determining that one of the plurality of ambient atmosphere forming paths with the shortest ventilation time as the dominant ambient atmosphere forming path.

13. The control method according to claim 1, characterized by, Further comprising: setting a temperature and humidity threshold range, the temperature and humidity threshold range including a temperature upper limit threshold, a temperature lower limit threshold, a humidity upper limit threshold and a humidity lower limit threshold; when the ambient atmosphere parameter exceeds any one of the temperature upper limit threshold, the temperature lower limit threshold, the humidity upper limit threshold and the humidity lower limit threshold, the preset ambient atmosphere parameter is re-determined according to the corresponding threshold.

14. The control method according to claim 13, characterized by, The re-determination of the preset ambient atmosphere parameter includes: re-determining the starting point of the temperature change curve of the preset ambient atmosphere and / or re-determining the starting point of the humidity change curve of the preset ambient atmosphere according to the corresponding threshold.

15. The control method according to claim 13, characterized by, The sensor is controlled to monitor the ambient atmosphere parameter in the wafer chamber in real time, and the preset ambient atmosphere parameter is re-determined according to the ambient atmosphere parameter in the wafer chamber monitored in real time.

Images