Method for cleaning an intake pipe and semiconductor process apparatus

Abstract

The application discloses a cleaning method of a gas inlet pipe and a semiconductor process equipment. The gas inlet pipe is used as a plasma generating cavity and is used for introducing plasma into a process chamber to process a wafer. The cleaning method comprises the following steps: after the process of a preset number of wafers is completed, a first cleaning gas is introduced into the gas inlet pipe, and a radio frequency power is loaded to excite the first cleaning gas; the air pressure in the gas inlet pipe is controlled to be maintained at a first preset pressure for a first preset time and at a second preset pressure for a second preset time, the ratio of the first preset pressure to the second preset pressure is greater than or equal to 6 and less than or equal to 14, and the ratio of the first preset time to the second preset time is greater than or equal to 0.5 and less than or equal to 2. The batch cleaning of the gas inlet pipe can clean the impurity particles, so that the flower-shaped defects are avoided, the gas inlet pipe is cleaned in time due to crystallization, the gas inlet pipe does not need to be frequently stopped and replaced, the service life of the gas inlet pipe is prolonged, the cost is reduced, and the production rate is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a method for cleaning an air intake pipe and semiconductor process equipment. Background Art

[0002] Most plasma etching processes are followed by a separate photoresist removal process, typically performed in a photoresist stripper. The process works as follows: plasma enters the process chamber through an inlet pipe and is filtered by an isolation plate, a metal filter covered in tiny holes. The isolation plate filters the plasma, producing relatively pure free radicals that etch the photoresist on the wafer surface, ultimately removing it.

[0003] As the process progresses and the number of wafers processed increases, a defect gradually develops on the surface of subsequent wafers. The distribution of these defects closely resembles the distribution of holes in the isolation plate, exhibiting a very regular pattern. This defect is known as a flower-shaped defect. At this point, production must be stopped for cleaning and maintenance of the degumming machine, significantly impacting machine capacity. Summary of the Invention

[0004] In response to the above technical problems, the present application provides an intake pipe cleaning method and semiconductor process equipment, which can improve the problem of existing methods in which flower-shaped defects caused by impurities falling from the intake pipe of the semiconductor process equipment require shutdown maintenance, affecting production capacity.

[0005] To solve the above technical problems, in a first aspect, embodiments of the present application provide a method for cleaning an air inlet pipe, wherein the air inlet pipe serves as a plasma generating chamber and is used to introduce plasma into a process chamber for processing wafers. The cleaning method includes an inter-batch cleaning step, wherein the inter-batch cleaning step includes:

[0006] After completing the process of a preset number of wafers, a first cleaning gas is introduced into the gas inlet pipe, and radio frequency power is applied to excite the first cleaning gas;

[0007] The air pressure in the intake pipe is controlled to be maintained at a first preset pressure for a first preset time, and at a second preset pressure for a second preset time, wherein the ratio of the first preset pressure to the second preset pressure is greater than or equal to 6 and less than or equal to 14, and the ratio of the first preset time to the second preset time is greater than or equal to 0.5 and less than or equal to 2.

[0008] Optionally, the first preset pressure is 3000-4200 mTorr, and the second preset pressure is 300-500 mTorr; and / or

[0009] The first preset time is 10-20 seconds, and the second preset time is 10-20 seconds; and / or

[0010] The radio frequency power is 1500-2500W.

[0011] Optionally, the first cleaning gas includes a fluorine-containing gas, and the volume proportion of the fluorine-containing gas is 1%-3%;

[0012] The air pressure in the air intake pipe switches between a first preset pressure and a second preset pressure, and the cycle is repeated more than twice.

[0013] Optionally, the first cleaning gas further includes an oxygen-containing gas, and the ratio of oxygen element to fluorine element in the first cleaning gas is 10:(0.3-1).

[0014] Optionally, the oxygen-containing gas is O2, the fluorine-containing gas is CF4, and the flow ratio of O2 to CF4 is 20:(0.3-1).

[0015] Optionally, the flow rate of O2 is 1800-2200 sccm, and the flow rate of CF4 is 27-110 sccm.

[0016] Optionally, the cleaning method further comprises:

[0017] Pre-wafer cleaning step: before the first wafer is processed, a second cleaning gas is introduced into the gas inlet pipe, and the radio frequency power is applied to excite the second cleaning gas to clean organic particles; and / or,

[0018] Inter-wafer cleaning step: After each wafer process is completed, the second cleaning gas is introduced into the gas inlet pipe, and the radio frequency power is applied to excite the second cleaning gas to clean organic particles.

[0019] Optionally, the second cleaning gas includes an oxygen-containing gas and does not contain fluorine.

[0020] In a second aspect, an embodiment of the present application further provides a semiconductor process equipment, comprising a process chamber, an inlet pipe for introducing gas into the process chamber, a radio frequency device for exciting the gas in the inlet pipe to form plasma, and a controller, wherein the controller comprises at least one processor and at least one memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the inlet pipe cleaning method described in the above embodiments is implemented.

[0021] Optionally, the air inlet pipe includes an inner pipe and a cooling member provided on a pipe wall of the inner pipe;

[0022] The cooling element is used to cool the inner tube.

[0023] As described above, the intake pipe cleaning method of the present application controls the air pressure in the intake pipe to maintain at a first preset pressure for a first preset time, and at a second preset pressure for a second preset time, and the ratio of the first preset pressure to the second preset pressure is greater than or equal to 6 and less than or equal to 14. Since the amount of plasma under high pressure is large and the mean free path is short, high-pressure cleaning for the first preset time can remove impurity particles over a large area, thereby improving cleaning efficiency. Plasma bombardment is stronger under low pressure, and low-pressure cleaning for the second preset time can avoid damage to the intake pipe caused by long-term high-pressure cleaning, thereby reducing the service life of the intake pipe, and further ensure that impurity particles are completely removed (cleaned thoroughly). In addition, controlling the ratio of the first preset time to the second preset time to be greater than or equal to 0.5 and less than or equal to 2 can achieve a good balance between avoiding damage to the intake pipe caused by excessive cleaning and cleaning thoroughly.

[0024] This application can avoid flower-shaped defects caused by continuous long-term processes by cleaning the intake pipe between batches. At the same time, since the entire process of the inter-batch cleaning step can be automatically controlled, impurity particles are cleaned in time and there is no need to frequently shut down to replace the intake pipe. This not only greatly extends the life of the intake pipe and reduces the cost of consumables, but also improves the productivity of semiconductor process equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without inventive work.

[0026] Figure 1 This is a schematic structural diagram of a semiconductor process equipment provided by an embodiment of the present application;

[0027] Figure 2 1 is a flow chart of a method for cleaning an air intake pipe provided in an embodiment of the present application;

[0028] Figure 3 This is a flow chart of another intake pipe cleaning method combined with an etching process provided in an embodiment of the present application;

[0029] Figure 4 This is a schematic structural diagram of an air intake pipe provided in an embodiment of the present application;

[0030] Figure 5 This is a structural schematic diagram of an isolation plate provided in an embodiment of the present application.

[0031] The purpose of this application, its features, and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings. The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and the accompanying text are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of this application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0032] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0033] It should be noted that, in this document, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, components, features, and elements with the same name in different embodiments of the present application may have the same meaning or different meanings, and their specific meanings need to be determined by their explanation in the specific embodiment or further combined with the context of the specific embodiment.

[0034] It should be further understood that the terms "comprising" and "including" indicate the presence of the described features, steps, operations, elements, components, items, kinds, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms "or", "and / or", "including at least one of the following", etc. used in this application may be interpreted as inclusive, or mean any one or any combination. For example, "including at least one of the following: A, B, C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C", and for another example, "A, B or C" or "A, B and / or C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C". Exceptions to this definition will only occur when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way.

[0035] It should be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are merely used to distinguish information of the same type from one another. For example, first information could also be referred to as second information, and similarly, second information could also be referred to as first information without departing from the scope of this document. Depending on the context, as used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context indicates otherwise.

[0036] It should be understood that the terms "top", "bottom", "up", "down", "vertical", "horizontal", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0037] For ease of description, the following embodiments are all described using the orthogonal space formed by the horizontal plane and the vertical direction as an example. This premise should not be understood as a limitation to the present application.

[0038] As mentioned above, as semiconductor processes like etching and stripping progress and the number of wafers processed increases, a type of defect gradually develops on the surface of subsequent wafers. The distribution of these defects closely resembles the distribution of holes in the isolation plate, exhibiting a very regular pattern. These defects are known as flower-shaped defects. In such cases, production must be halted for cleaning and maintenance of semiconductor process equipment, significantly impacting machine capacity.

[0039] The applicant has conducted research on this. Since plasma generates heat during the excitation process, and the semiconductor process equipment itself also works at high temperature, this places extremely high demands on the heat resistance of each component. The component that bears the most heat radiation and heat conduction is the air intake pipe. The air intake pipe itself is at room temperature, and the gas introduced is also at room temperature. During the process, radio frequency devices such as microwave sources excite the gas in the air intake pipe into plasma, so that the air intake pipe and the process chamber are both in a high-temperature state. At the same time, the process of plasma dissociation in the air intake pipe also generates a large amount of heat energy, which increases the temperature of the air intake pipe. Under the high and low temperature impact of the internal and external environments, the interior of the air intake pipe is easily roughened by the airflow to produce impurity particles (crystallization). The impurity particles will be brought into the process chamber by the airflow. Some of the impurity particles will adhere to the holes in the isolation plate and are gradually impacted by the gas and eventually fall on the wafer surface. The impurity particles block the free radical etching and form the above-mentioned flower-shaped defects.

[0040] To address the aforementioned issues, as a reference example, the condition of the intake duct can be monitored. For example, a photoresist-coated control wafer can be used to simulate etching in semiconductor process equipment, such as a stripper. The impurity particles on the wafer surface can be measured, and the number and distribution of particles can be used to understand the current condition of the intake duct. If the impurities on the wafer surface develop a flower-like distribution, immediate machine maintenance and replacement of the intake duct are required. Real-time monitoring can only prevent flower-like defects in products, but cannot eliminate them or extend the life of the intake duct. Furthermore, monitoring methods have certain limitations. The frequency of monitoring and the production capacity of the machine are in conflict. If the monitoring frequency is too high, the time available for production will be significantly reduced. However, if the frequency is too low, even if a defect is discovered, many products may have already developed flower-like defects. This monitoring method cannot achieve a balance between production capacity and safety. Frequent replacement of the intake duct not only significantly increases consumable costs, but also requires time for the replacement process and chamber recovery, further reducing production capacity. Based on this, the present application provides an intake duct cleaning method and semiconductor process equipment.

[0041] First, the application environment of the air intake pipe cleaning method of this application is introduced. Figure 1 , Figure 1 This is a structural schematic diagram of a semiconductor process equipment provided in an embodiment of the present application. The semiconductor process equipment may include a process chamber 10, an air inlet pipe 20 for introducing gas into the process chamber 10, and a radio frequency device 30 for exciting the gas in the air inlet pipe 20 to form plasma. The air inlet pipe 20 itself serves not only as an air inlet pipe, but also as a plasma generating chamber. The radio frequency device 30 may be a microwave system that excites the process gas to form plasma through microwaves. An isolation plate 40 may also be provided in the process chamber 10 to filter ions in the plasma and allow only free radicals to pass through. The free radicals are used to etch the photoresist 101 on the wafer 100. The semiconductor process equipment may be used to remove photoresist, and may also be applied to deposition processes, other etching processes, etc., such as isotropic etching that requires ion filtration.

[0042] See also Figure 2 , Figure 2 1 is a flow chart of a method for cleaning an air intake pipe provided in an embodiment of the present application. The method includes an inter-batch cleaning step, which may include S110-S120.

[0043] S110 , after completing the process of a preset number of wafers, introducing a first cleaning gas into the gas inlet pipe, and applying radio frequency power to excite the first cleaning gas.

[0044] As described above, the outside of the gas inlet pipe 20 is at room temperature, and the inside is at high temperature due to the large amount of heat generated by gas dissociation. Under the high and low temperature collision of the inside and outside environments, impurity particles (crystallization) are easily generated inside the gas inlet pipe 20, which will be brought into the process chamber by the gas flow, and then flower-shaped defects will be generated.

[0045] The flower-shaped defects are generally generated after a certain number of wafers are etched. Therefore, the above number can be determined in advance by experiment. Assuming that the number is 20, the first cleaning gas can be introduced into the gas inlet pipe and the radio frequency power can be loaded to excite the first cleaning gas to clean the gas inlet pipe 20 once to remove the crystallization after every 15 wafers (i.e., the preset number) are etched. The number of a batch is 15, and can also be other numbers less than 20.

[0046] In S120, the gas pressure in the gas inlet pipe is controlled to be maintained at a first preset pressure for a first preset time, and maintained at a second preset pressure for a second preset time. The ratio of the first preset pressure to the second preset pressure is greater than or equal to 6 and less than or equal to 14, and the ratio of the first preset time to the second preset time is greater than or equal to 0.5 and less than or equal to 2.

[0047] The principle of cleaning is that the first cleaning gas reacts with the impurity particles, and the reaction products are discharged from the gas inlet pipe 20 with the gas flow to achieve the purpose of cleaning. It can be understood that the impurity particles in the gas inlet pipe 20, the inner wall of the process chamber 10 and the filter holes of the isolation plate 40 can be removed.

[0048] In this step, the gas pressure in the gas inlet pipe is controlled to be maintained at a first preset pressure for a first preset time, and maintained at a second preset pressure for a second preset time, and the ratio of the first preset pressure to the second preset pressure is greater than or equal to 6 and less than or equal to 14. The ratio can be 6, 8, 11, 14, etc. Due to the large number of plasma under high pressure and the short mean free path, the high-pressure cleaning for the first preset time can remove impurity particles in a large area and improve the cleaning efficiency. The plasma bombardment ability is stronger under low pressure, and the low-pressure cleaning for the second preset time can avoid damage to the gas inlet pipe 20 caused by long-time high-pressure cleaning, reduce the service life of the gas inlet pipe 20, and further ensure complete removal of impurity particles (cleaning). In addition, the ratio of the first preset time to the second preset time is greater than or equal to 0.5 and less than or equal to 2. The ratio can be 0.5, 0.7, 1.0, 1.3, 1.7, 2.0, etc. A good balance between avoiding excessive cleaning to cause damage to the gas inlet pipe 20 and cleaning completely can be achieved.

[0049] The cleaning method of this embodiment can avoid flower-shaped defects caused by continuous long-term processes by cleaning the air intake pipe 20 between batches. At the same time, since the entire process of the cleaning steps between batches can be automatically controlled, impurity particles are cleaned in a timely manner, and there is no need to frequently shut down to replace the air intake pipe 20. This not only greatly extends the life of the air intake pipe 20 and reduces the cost of consumables, but also improves the productivity of semiconductor process equipment.

[0050] As some examples, the first preset pressure of the process chamber 10 during the inter-batch cleaning step may be 3000-4200 mTorr, and the second preset pressure may be 300-500 mTorr. For example, the first preset pressure may be 3000 mTorr, 3200 mTorr, 3600 mTorr, 4000 mTorr, 4200 mTorr, etc., and the second preset pressure may be 300 mTorr, 330 mTorr, 370 mTorr, 420 mTorr, 500 mTorr, etc. Excessive or insufficient pressure may result in incomplete cleaning, over-cleaning that may damage the air intake pipe 20, or even cause the air intake pipe 20 to overheat and crack.

[0051] As some examples, the first preset time in the inter-batch cleaning step may be 10-20 seconds, and the second preset time may be 10-20 seconds. For example, the first preset time may be 10 seconds, 13 seconds, 18 seconds, 20 seconds, etc., and the second preset time may be 10 seconds, 13 seconds, 18 seconds, 20 seconds, etc. A cleaning time that is too long or too short may result in incomplete cleaning or damage to the intake pipe 20 due to over-cleaning.

[0052] As some examples, the RF power applied during the inter-batch cleaning step may be 1500-2500 W, for example, the RF power may be 1500 W, 1700 W, 2000 W, 2500 W, etc. Excessive or insufficient RF power may result in incomplete cleaning or damage the intake pipe 20 due to over-cleaning.

[0053] The air intake pipe 20 is generally a quartz tube, and the main component of the impurity particles produced by crystallization is SiO2. Therefore, when performing inter-batch cleaning, the first cleaning gas can be a gas that can react with SiO2. For example, the first cleaning gas can include a fluorine-containing gas, and the volume proportion of the fluorine-containing gas is 1%-3%, so as to avoid excessive cleaning caused by too fast a cleaning speed. When performing inter-batch cleaning, the air pressure in the air intake pipe 20 is switched between the first preset pressure and the second preset pressure, and the cycle is repeated more than 2 times. The specific number of cycles can be selected in combination with the volume proportion of the fluorine-containing gas. This embodiment can completely remove impurity particles and minimize damage to the air intake pipe 20 through high and low pressure cycle cleaning.

[0054] In one embodiment, the first cleaning gas includes an oxygen-containing gas in addition to the fluorine-containing gas, and the ratio of oxygen to fluorine in the first cleaning gas is 10:(0.3-1). In this embodiment, by adding a certain proportion of oxygen-containing gas, organic particles in the intake pipe 20 and the air path downstream of the intake pipe 20 can be cleaned, thereby further improving the cleanliness of the intake pipe.

[0055] As some examples, fluorine-containing gases can include at least one of SF6, NF3, CF4, C2F6, C4F8, C5F8, and C4F6. Semiconductor processing equipment typically uses a limited number of gases, typically only CF4. Using other gases would require the facility to add new pipelines and undergo safety verification. Therefore, CF4 is preferably the fluorine-containing gas.

[0056] In one embodiment, the oxygen-containing gas is O2, the fluorine-containing gas is CF4, and the flow ratio of O2 to CF4 is 20:(0.3-1). O2 can oxidize and remove carbide particles. The CF4 flow rate should not be too low, as this may not effectively remove impurity particles generated by the intake pipe 20. The CF4 flow rate should also not be too high, as this may cause over-cleaning and damage the intake pipe 20. It may also generate excessive energy, causing the intake pipe 20 to overheat and crack.

[0057] The first cleaning gas may also include a diluent gas, such as N2, to control the chemical reaction rate during cleaning. For example, the first cleaning gas may be N2, O2, and CF4, with a flow ratio of 10:20:(0.3-1). As an example, the flow rate of N2 is 900-1100 sccm, the flow rate of O2 is 1800-2200 sccm, and the flow rate of CF4 is 27-110 sccm.

[0058] As an example of an inter-batch cleaning step, O2 gas may be introduced to evacuate the process chamber 10 first, and then the first cleaning gas may be introduced. After the pressure stabilizes, the RF device 30 may be started for cleaning.

[0059] In one embodiment, the method for cleaning the air intake pipe may further include a pre-chip cleaning step and / or an inter-chip cleaning step.

[0060] Pre-wafer cleaning step: Before the first wafer is processed, a second cleaning gas is introduced into the gas inlet pipe, and radio frequency power is applied to excite the second cleaning gas to clean organic particles.

[0061] Before the first wafer is etched in the process chamber 10, a pre-wafer cleaning step, i.e. waferless auto clean (WAC), is performed to ensure that each wafer is etched in the same chamber environment. The step can be performed by using conventional processes in the art, which are not particularly limited in the present embodiment.

[0062] Inter-wafer cleaning step: after the process of each wafer is completed, the second cleaning gas is introduced into the gas inlet pipe, and the radio frequency power is loaded to excite the second cleaning gas to perform the organic particle cleaning.

[0063] For example, after the etching process of the photoresist, carbide residues, i.e. organic particles, can be formed in the process chamber 10. In order to improve the yield, after each wafer is etched, the process chamber 10 can be cleaned by using the second cleaning gas to clean the organic particles. The step can be completely referred to the pre-wafer cleaning step.

[0064] Please refer to Figure 3 , Figure 3 is another cleaning method of the gas inlet pipe combined with the etching process provided in the present embodiment. The flowchart can include S210-S240.

[0065] S210, pre-wafer cleaning step: before the process of the first wafer is performed, the second cleaning gas is introduced into the gas inlet pipe 20, and the radio frequency power is loaded to excite the second cleaning gas to perform the organic particle cleaning.

[0066] S220, etching step: the etching gas is introduced into the process chamber 10 from the gas inlet pipe 20, and the radio frequency device 30 is turned on to etch the wafer surface, for example, to remove the photoresist on the wafer surface.

[0067] The step can be performed by using conventional etching process formula in the art, including the type of etching gas, gas flow, ignition power of the radio frequency device 30, pressure in the process chamber 10, etc., which are not particularly limited in the present embodiment. In the present embodiment, a counter can be set. When each wafer is etched, the number is increased by 1. When the number recorded by the counter is less than the preset number, the inter-wafer cleaning step S230 is performed, otherwise the batch cleaning step S240 is performed.

[0068] S230, inter-wafer cleaning step: after each wafer is etched, the second cleaning gas is introduced into the gas inlet pipe 20, and the radio frequency power is loaded to excite the second cleaning gas to perform the organic particle cleaning.

[0069] S240, batch cleaning step: specific embodiments can be referred to the embodiments of S110-S120.

[0070] This embodiment can ensure that the first wafer can be etched in a clean chamber environment through the pre-wafer cleaning step, and can ensure that each wafer can be etched in a clean chamber environment through the inter-wafer cleaning step. Since both the pre-wafer cleaning step and the inter-wafer cleaning step cannot remove SiO2, the impurity particles generated by crystallization of the intake pipe 20 are further removed in time through the inter-batch cleaning step, which can avoid flower-shaped defects caused by continuous long-term etching. This embodiment does not require frequent shutdown to replace the intake pipe 20, which not only greatly extends the life of the intake pipe 20 and reduces the cost of consumables, but also improves the productivity of semiconductor process equipment.

[0071] As an example, in the above-mentioned pre-wafer cleaning step and the inter-wafer cleaning step, the second cleaning gas may include an oxygen-containing gas and does not contain fluorine. For example, the second cleaning gas may be a mixed gas of N2 and O2, and the flow ratio of N2 to O2 is (0.9-1.1):2. In addition, in the step of cleaning organic particles, the pressure of the process chamber 10 may be 1750-2300 mTorr, the RF power of the RF device 30 may be 1500-2500 W, and the cleaning time may be 60-120 s.

[0072] The following combination Figure 3 The cleaning method of the air intake pipe of the present application is described in detail with a specific embodiment. The process formula is set as follows:

[0073] The main process recipes of S210 and S230 are as follows: the pressure of the process chamber 10 is 2000 mTorr, the flow rate of N2 is 1000 sccm, the flow rate of O2 is 2000 sccm, the RF power of the RF device 30 is 2000 W, and the cleaning time is 100 s.

[0074] The main process formula of S240 is as follows: the first preset pressure of the process chamber 10 is 3500mTorr, the first preset time is 15s, the second preset pressure is 400mTorr, the second preset time is 15s, the flow rate of N2 is 1000sccm, the flow rate of O2 is 2000sccm, the flow rate of CF4 is 75, and the RF power of the RF device 30 is 2000w.

[0075] Etching was simulated on semiconductor process equipment using control wafers coated with photoresist. Impurity particle testing was performed every 50 wafers. Without the S240 inter-batch cleaning step, when the experiment reached the 200th wafer, obvious particle aggregation appeared in two areas of the wafer. By the 400th wafer, a complete flower map defect appeared.

[0076] After adding the S240 inter-batch cleaning step, the preset number was 10 wafers, that is, S240 was performed once for every 10 wafers etched. When the simulated etching reached 600 wafers, impurity particles accumulated in one area on the wafer. When it reached 1300 wafers, a complete flower-shaped defect appeared.

[0077] From the above comparative experiments, it can be seen that adding the S240 inter-batch cleaning step can greatly extend the service life of the intake pipe 20, which is of great significance for alleviating flower-shaped defects in actual mass production.

[0078] The present application also provides a semiconductor process equipment. Figure 1 , including a process chamber 10, an air inlet pipe 20 for introducing gas into the process chamber 10, a radio frequency device 30 for exciting the gas in the air inlet pipe 20 to form plasma, and a controller, the controller including at least one processor and at least one memory, the memory storing a computer program, and when the computer program is executed by the processor, the air inlet pipe cleaning method described in the above embodiments is implemented.

[0079] As an example, see Figure 4 , Figure 4 This is a structural schematic diagram of an intake pipe provided in an embodiment of the present application. The intake pipe 20 may include an inner pipe 21 and a cooling pipe 22 arranged on the outside of the inner pipe 21. The cooling pipe 22 may be a spiral structure wound around the outside of the inner pipe 21.

[0080] As an example, see Figure 5 , Figure 5 1 is a schematic structural diagram of an isolation plate provided in an embodiment of the present application. An isolation plate 40 may also be provided in the process chamber 10 . The isolation plate 40 is provided with filter holes 41 for filtering ions in the plasma.

[0081] For other working principles and processes of the semiconductor process equipment of this embodiment, please refer to the description of the cleaning method of the air intake pipe in the aforementioned embodiment of the present invention, which will not be repeated here.

[0082] The above describes in detail the air intake pipe cleaning method and semiconductor process equipment provided by this application. This article uses specific examples to illustrate the principles and implementation methods of this application. It should be noted that the descriptions of each embodiment in this application have different emphases. For portions not detailed or documented in one embodiment, please refer to the relevant descriptions of other embodiments.

[0083] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. The various technical features of the technical solution of the present application can be arbitrarily combined. In order to make the description concise, all possible combinations of the various technical features in the above embodiments are not described. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, as long as there is no contradiction in the combination of these technical features, are also included in the patent protection scope of the present application.

Claims

1. A method for cleaning an air intake pipe, characterized in that: The air inlet pipe serves as a plasma generating chamber and is used to introduce plasma into the process chamber to process the wafers. The cleaning method includes an inter-batch cleaning step, which includes: After completing the process of a preset number of wafers, a first cleaning gas is introduced into the gas inlet pipe, and radio frequency power is applied to excite the first cleaning gas; The air pressure in the intake pipe is controlled to be maintained at a first preset pressure for a first preset time, and at a second preset pressure for a second preset time, wherein the ratio of the first preset pressure to the second preset pressure is greater than or equal to 6 and less than or equal to 14, and the ratio of the first preset time to the second preset time is greater than or equal to 0.5 and less than or equal to 2.

2. The cleaning method according to claim 1, wherein The first preset pressure is 3000-4200 mTorr, and the second preset pressure is 300-500 mTorr; and / or The first preset time is 10-20 seconds, and the second preset time is 10-20 seconds; and / or The radio frequency power is 1500-2500W.

3. The cleaning method according to claim 1, wherein The first cleaning gas includes a fluorine-containing gas, and the volume proportion of the fluorine-containing gas is 1%-3%; The air pressure in the air intake pipe switches between a first preset pressure and a second preset pressure, and the cycle is repeated more than twice.

4. The cleaning method according to claim 3, wherein The first cleaning gas further includes an oxygen-containing gas, and the ratio of oxygen to fluorine in the first cleaning gas is 10:(0.3-1).

5. The cleaning method according to claim 4, wherein: The oxygen-containing gas is O2, the fluorine-containing gas is CF4, and the flow ratio of O2 to CF4 is 20:(0.3-1).

6. The cleaning method according to claim 5, characterized in that The flow rate of the O2 is 1800-2200 sccm, and the flow rate of the CF4 is 27-110 sccm.

7. The cleaning method according to claim 1, wherein Also includes: Pre-wafer cleaning step: before the first wafer is processed, a second cleaning gas is introduced into the gas inlet pipe, and the radio frequency power is applied to excite the second cleaning gas to clean organic particles; and / or, Inter-wafer cleaning step: After each wafer process is completed, the second cleaning gas is introduced into the gas inlet pipe, and the radio frequency power is applied to excite the second cleaning gas to clean organic particles.

8. The cleaning method according to claim 7, wherein: The second cleaning gas includes oxygen-containing gas and does not contain fluorine element.

9. A semiconductor process equipment, characterized in that: The invention comprises a process chamber, an air inlet pipe for introducing gas into the process chamber, a radio frequency device for exciting the gas in the air inlet pipe to form plasma, and a controller, wherein the controller comprises at least one processor and at least one memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the air inlet pipe cleaning method according to any one of claims 1 to 8 is implemented.

10. The semiconductor process equipment according to claim 9, wherein: The air intake pipe includes an inner pipe and a cooling element arranged on a pipe wall of the inner pipe; The cooling element is used to cool the inner tube.

Images