Semiconductor cleaning apparatus and cleaning method

Abstract

The application provides a semiconductor cleaning device and a cleaning method, which comprise a rack, a process tube, a fixing support, a radio frequency induction coil and a driving device. The process tube has a cavity inside, and the cavity is used for accommodating a graphite boat to be cleaned. The fixing support is connected with the rack and is movable relative to the rack. The radio frequency induction coil is arranged around the outer periphery of the process tube, and each turn of the radio frequency induction coil is fixed on the fixing support. The radio frequency induction coil is used for forming a plasma of a process gas in the process tube. The driving device is used for driving the fixing support to move in a first direction, so as to drive the radio frequency induction coil to move in the first direction relative to the process tube. The first direction is parallel to the length direction of the process tube. The graphite boat is cleaned by using the semiconductor cleaning device. The radio frequency induction coil surrounds part of the process tube, so that the graphite boat is cleaned in sections, and the cleaning time is short.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and more specifically, to a semiconductor cleaning device and cleaning method. Background Technology

[0002] In the fabrication of crystalline silicon solar cells, the antireflective coating and / or passivation film on the silicon wafer surface are commonly achieved using plasma-enhanced chemical vapor deposition (PECVD). Specifically, a graphite boat is used to load the silicon wafer into a reaction chamber for coating. During the process, both the graphite boat and the silicon wafer are located within the reaction chamber. Reaction byproducts deposit on the graphite boat. Excessive thickness of these byproducts can cause impedance changes in the graphite boat, leading to deviations in subsequent processes and ultimately affecting the cell efficiency. Therefore, the graphite boat needs to be cleaned regularly.

[0003] Currently, dry cleaning technology is commonly used to clean graphite boats. Figure 1 A schematic diagram of a semiconductor cleaning device in the related art is shown. Figure 1 The semiconductor cleaning apparatus 100a shown includes a process tube 20a, a graphite boat 200 to be cleaned placed inside the process tube 20a, a process gas being introduced into the process tube 20a, and a radio frequency induction coil 30a wrapped around the outer periphery of the process tube, substantially enclosing the entire process tube 20a. This semiconductor cleaning apparatus 100a employs inductively coupled plasma (ICP) technology to clean the graphite boat 200.

[0004] However, this method of cleaning graphite boats takes a long time. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art, and proposes a semiconductor cleaning device and cleaning method.

[0006] To achieve the purpose of this invention, a semiconductor cleaning apparatus is provided. The semiconductor cleaning apparatus includes a frame, a process tube, a fixed support, a radio frequency induction coil, and a driving device. The process tube has a cavity inside for accommodating a graphite boat to be cleaned. The fixed support is connected to the frame and can move relative to the frame. The radio frequency induction coil is wound around the outer periphery of the process tube, and each turn of the wire of the radio frequency induction coil is fixed on the fixed support. The radio frequency induction coil is used to cause the process gas inside the process tube to form plasma.

[0007] The driving device is used to drive the fixed bracket to move along a first direction, so as to drive the radio frequency induction coil to move relative to the process tube along the first direction; wherein, the first direction is parallel to the length direction of the process tube.

[0008] In the semiconductor cleaning equipment described above, the length of the radio frequency induction coil is less than one-quarter of the wavelength of the radio frequency signal applied to the radio frequency induction coil.

[0009] In the semiconductor cleaning equipment described above, the length of the radio frequency induction coil is less than one-tenth of the wavelength of the radio frequency signal.

[0010] The semiconductor cleaning equipment described above further includes a radio frequency (RF) power supply disposed outside the process tube, which is used to output RF signals; the two ends of the RF induction coil are an input terminal and a ground terminal, respectively; the semiconductor cleaning equipment also includes a first connector and a second connector mounted on a fixed bracket, the first connector being connected to the input terminal and the second connector being connected to the ground terminal, and the first connector and the second connector being electrically connected to the RF power supply respectively via flexible cables.

[0011] As described above, the semiconductor cleaning equipment includes two fixed supports arranged opposite to each other, with the process tube located between the two fixed supports; the first connector and the second connector are mounted on the same fixed support.

[0012] In the semiconductor cleaning equipment described above, there is a gap between the radio frequency induction coil and the outer surface of the process tube.

[0013] In the semiconductor cleaning equipment described above, the gap along the radial dimension of the process tube is greater than or equal to 10 mm and less than or equal to 50 mm.

[0014] In the semiconductor cleaning equipment described above, the mounting bracket includes a metal mounting plate and an insulating plate, the insulating plate being fixedly connected to the metal mounting plate, and each turn of the RF induction coil is fixed on the side of the insulating plate facing the process tube to insulate and isolate the RF induction coil from the metal mounting plate.

[0015] In the semiconductor cleaning equipment described above, a plurality of limiting spaces are formed on the side of the insulating plate facing the process tube, and each turn of the RF induction coil is correspondingly inserted into one limiting space, thereby restricting the displacement of each turn of the coil along the thickness direction of the insulating plate.

[0016] In the semiconductor cleaning equipment described above, a metal mounting plate is recessed in the direction away from the process tube to form a groove, an insulating plate is located in the groove, and the thickness of the insulating plate is equal to the depth of the groove; and / or, the fixing bracket further includes a plurality of limiting plates, at least one end of the limiting plate along a first direction is fixedly connected to the side of the insulating plate facing the process tube, and the limiting plate and the insulating plate together enclose a limiting space.

[0017] In the semiconductor cleaning equipment described above, the frame is provided with multiple slides that extend along a first direction; the metal mounting plate is provided with sliders at both ends along a second direction, and each slider is slidably engaged with a slide; wherein the second direction is perpendicular to the first direction and the thickness direction of the metal mounting plate.

[0018] In the semiconductor cleaning equipment described above, the driving device includes a drive motor and a transmission device. The drive motor is mounted on the frame, and the transmission device is used to convert the rotational power of the drive motor into linear power and transmit it to the metal mounting plate to drive the metal mounting plate to move along a first direction.

[0019] The semiconductor cleaning equipment described above further includes a connecting support, a motor support, and a supporting support. The connecting support is fixedly connected to the frame, one end of the supporting support is connected to the connecting support, and the other end is connected to the motor support. The drive motor is fixedly mounted on the motor support.

[0020] As described above, the semiconductor cleaning equipment includes a main frame and a partition frame. The main frame is a cuboid frame structure, and the partition frame is a rectangular frame structure. The partition frame is disposed inside the main frame to divide the main frame into a first space and a second space. The process tube is located in the first space, and the connecting support, motor support, and support support are all located in the second space.

[0021] As described above, the semiconductor cleaning equipment includes a transmission device comprising a synchronous shaft, a driving pulley, a driven pulley, and a conveyor belt. The synchronous shaft is connected to the motor shaft of a drive motor. The driving pulley is mounted on the synchronous shaft. The driven pulley is rotatably connected to the frame. The rotation axis of the driven pulley is parallel to the rotation axis of the synchronous shaft. The conveyor belt is wound between the driving pulley and the driven pulley. A transmission component is fixedly mounted on the conveyor belt and is fixedly connected to a metal mounting plate.

[0022] As another technical solution, the present invention also provides a cleaning method, applied to any of the semiconductor cleaning devices provided by the present invention, the cleaning method comprising:

[0023] The graphite boat to be cleaned is placed into the cavity of the process tube; wherein, the graphite boat has multiple boat segments arranged sequentially along a first direction;

[0024] In the boat section cleaning step, the control drive device drives the fixed bracket to move relative to the process tube along the first direction, so as to move the radio frequency induction coil along the first direction to surround the outer periphery of one of the boat sections, load radio frequency power onto the radio frequency induction coil, so that the process gas in the cavity forms plasma, and maintain the position of the radio frequency induction coil for a preset time, so that the boat section is cleaned.

[0025] Repeat the boat segment cleaning steps until all boat segments have been cleaned.

[0026] In the cleaning method described above, the radio frequency induction coil initially surrounds the outer periphery of a boat segment near the furnace opening of the process tube; during the cleaning of all the boat segments, each boat segment is cleaned sequentially from the furnace opening to the furnace tail of the process tube.

[0027] In the cleaning method described above, the radio frequency induction coil initially surrounds the outer periphery of a boat segment near the furnace tail of the process tube; during the cleaning of all the boat segments, each boat segment is cleaned sequentially from the furnace tail of the process tube to the furnace mouth of the process tube.

[0028] The cleaning method described above, wherein after the boat section cleaning step and before repeating the boat section cleaning step, the cleaning method further includes: stopping the application of radio frequency power to the radio frequency induction coil.

[0029] The present invention has the following beneficial effects:

[0030] The semiconductor cleaning equipment provided by this invention features a shorter radio frequency (RF) induction coil. The RF induction coil only surrounds a portion of the graphite boat's outer perimeter. A driving device moves the RF induction coil to clean the graphite boat segment by segment, effectively avoiding the long cleaning time caused by excessively long RF induction coils resulting in high resistance. Thus, while ensuring thorough cleaning of the entire graphite boat, the shorter RF induction coil in this embodiment leads to lower resistance, higher current, and a higher concentration of plasma excited by the electromagnetic field generated by the RF induction coil, resulting in a shorter cleaning time for the graphite boat. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a semiconductor cleaning device in the related art;

[0032] Figure 2 This is a schematic diagram of the structure of a semiconductor cleaning device provided in an embodiment of this application;

[0033] Figure 3 A side view of a semiconductor cleaning apparatus provided in an embodiment of this application;

[0034] Figure 4 A schematic diagram illustrating the working process of a semiconductor cleaning device provided in an embodiment of this application;

[0035] Figure 5 This is a schematic diagram illustrating the interaction between a fixed bracket, a radio frequency induction coil, and a process tube in a semiconductor cleaning device provided in an embodiment of this application.

[0036] Figure 6 A partial schematic diagram of the cooperation between a fixed bracket and a radio frequency induction coil in a semiconductor cleaning device provided in an embodiment of this application;

[0037] Figure 7 for Figure 2 A magnified view of point A in the semiconductor cleaning equipment shown;

[0038] Figure 8 for Figure 2 A magnified view of point B in the semiconductor cleaning equipment shown;

[0039] Figure 9 This is a schematic diagram of a cleaning method provided in an embodiment of this application.

[0040] Explanation of reference numerals in the attached figures:

[0041] 100-Semiconductor cleaning equipment;

[0042] 10-Rack; 11-Main rack; 12-Separator rack;

[0043] 20-Process tube; 21-Ring body; 22-Furnace door;

[0044] 30 - Radio frequency induction coil;

[0045] 40 - RF power supply; 41 - Flexible cable; 42 - First connector; 43 - Second connector;

[0046] 50-Fixed bracket; 51-Metal mounting plate; 511-Flange; 52-Insulating plate; 53-Limiting plate; 54-Connecting plate; 55-Slider;

[0047] 60-Drive motor; 61-Conveyor belt; 611-Transmission component; 612-Pressure plate; 63-Drive pulley;

[0048] 64-Support bracket; 65-Motor bracket; 66-Connecting bracket;

[0049] 70-Guide rail;

[0050] 200-Graphite Boat. Detailed Implementation

[0051] The following embodiments of this application provide a semiconductor cleaning device for cleaning graphite boats. The cleaning method used is dry cleaning. Compared with wet cleaning, dry cleaning has advantages such as less environmental pollution and no need to disassemble the graphite boat to avoid mechanical damage caused by disassembly.

[0052] This semiconductor cleaning equipment specifically utilizes inductively coupled plasma (ICP) technology for cleaning. The cleaning principle is as follows: a process gas containing fluorine-based gases such as NF3, CF4, or C2F6, and oxygen is introduced into the process tube. A radio frequency (RF) induction coil wound around the outer periphery of the process tube generates a high-frequency electromagnetic field by applying RF power. This electromagnetic field induces an electric field inside the process tube, dissociating the fluorine-based gases into plasma. The following text uses NF3 as an example; specifically, electrons... - Electrons move under the influence of an induced electric field. - During the process, it reacts with NF3 according to the following formula (I), and NF3 is bombarded to produce fluorine radicals (F). * ), NF2 and electron e - NF2 will interact with electrons e - According to the following formula (II), NF2 is bombarded to produce fluorine radicals (F). * ), NF and electron e - NF will interact with electrons e - According to the following formula (iii), NF is bombarded to produce fluorine radicals (F). * N2 and electron e - .

[0053] e - +NF3→NF2+F*+e - Formula (1)

[0054] e - +NF2→NF+F*+e - Formula (II)

[0055] e - +NF→N2+F*+e - Formula (3)

[0056] In general, fluorine-based gases in the process gas are excited into plasma F. * The reaction byproducts on the graphite boat consisted of silicon nitride (SiN), and the plasma F... * The graphite boat is cleaned by reacting with SiN according to the following formula (iv). The gaseous SiF4 is discharged outside the process tube.

[0057] F*+SiN→SiF4↑+N2 Equation (IV)

[0058] Therefore, it can be understood that the uniformity of plasma is a crucial indicator affecting the cleaning quality during the graphite boat cleaning process. Furthermore, the uniformity of plasma is closely related to the uniformity of the electromagnetic field distribution within the process tube.

[0059] use Figure 1 When the semiconductor cleaning equipment 100a shown is used to clean the graphite boat 200, the cleaning time is relatively long. After careful research, the inventors of this application discovered that one of the reasons for this problem is that since the radio frequency induction coil 30a can almost wrap around the entire process tube 20a, the radio frequency induction coil 30a is long, resulting in a high resistance value. Consequently, the current on the radio frequency induction coil 30a is small, resulting in a low concentration of plasma and a long cleaning time.

[0060] Another reason for this problem is that the output impedance of the RF power supply that provides RF power to the RF induction coil 30a is generally 50 ohms. Due to the limitations of the manufacturing process, the impedance of the RF induction coil 30a is difficult to reach 50 ohms. Therefore, the impedance of the RF power supply and the RF induction coil 30a are mismatched, which leads to the reflection of the electromagnetic waves formed by the propagation of the electromagnetic field.

[0061] The radio frequency (RF) power supply outputs a sine wave, and RF signals are typically high-frequency signals with shorter wavelengths. If the operating frequency of the RF signal is set to 13.56MHz, the wavelength of that RF signal is approximately 22m. And... Figure 1 In the example shown, the RF induction coil 30a is wound from one end of the process tube 20a to the other, and the length of the RF induction coil 30a is much greater than one-quarter of the wavelength of the RF signal. This causes the incident and reflected waves to superimpose, forming a standing wave. The standing wave effect on the RF induction coil 30a results in different currents at different points on the coil, leading to an uneven distribution of the electromagnetic field generated by the coil and affecting the uniformity of plasma distribution within the process tube 20a. Specifically, the electromagnetic field strength corresponding to areas with lower current on the RF induction coil 30a is lower, resulting in lower plasma density in these areas within the process tube 20a. Consequently, the cleaning effect on the portion of the graphite boat 200 located in these areas is poor. To ensure that all parts of the graphite boat 200 meet the cleaning requirements, the cleaning process only ends when the portion of the graphite boat 200 located in the area with lower magnetic field strength is thoroughly cleaned; therefore, the cleaning time is long.

[0062] Based on this, embodiments of this application provide a semiconductor cleaning apparatus and cleaning method, which utilizes a movable radio frequency induction coil surrounding a portion of the process tubes to clean the graphite boat in segments. To enable those skilled in the art to better understand the technical solution of this invention, the semiconductor cleaning apparatus and cleaning method provided by this invention will be described in detail below with reference to the accompanying drawings.

[0063] Figure 2 This is a schematic diagram of the structure of a semiconductor cleaning device provided in an embodiment of this application. Figure 3 This is a side view of a semiconductor cleaning apparatus provided in an embodiment of this application. Please refer to... Figure 2 and Figure 3 As shown, the semiconductor cleaning equipment 100 includes a frame 10, a process tube 20, an air intake assembly, an air extraction assembly, an RF induction coil 30, and an RF power supply 40 disposed outside the process tube 20.

[0064] The process tube 20 has an interior cavity for accommodating the graphite boat 200 to be cleaned, and the process tube 20 is along a first direction (in Figure 2 The diagram shows X) with one end as the furnace opening and the other end as the furnace tail. Exemplarily, both the furnace opening and tail can be open. In this case, furnace doors 22 are movably connected to both the furnace opening and tail of the process tube 20, allowing the furnace opening and tail to be opened and closed. When the graphite boat 200 needs cleaning, the furnace door 22 at the furnace opening or the furnace door 22 at the furnace tail is opened, and a robotic arm is used to transfer the graphite boat 200 to be cleaned into the cavity. Then, the furnace door 22 is closed, creating a vacuum within the cavity for the cleaning process. After the cleaning process is complete, the furnace door 22 at the furnace opening or the furnace door 22 at the furnace tail is opened, and a robotic arm is used to remove the cleaned graphite boat 200. To improve the cavity's sealing, sealing rings can be provided between the furnace door 22 and the furnace opening, and between the furnace door 22 and the furnace tail, ensuring a sealed contact between the furnace door 22 and the process tube 20.

[0065] Of course, in some embodiments, the furnace tail of the process tube 20 can be closed, with only the furnace opening open. In this case, only the furnace opening is provided with a furnace door 22 to open and close the furnace opening. The aforementioned process tube 20 can be made of, for example, quartz or ceramic material.

[0066] The semiconductor cleaning equipment 100 also includes multiple rods 21. The rods 21 are located inside the process tube 20 and extend along a first direction X. One end of each rod 21 extends to the furnace opening, and the other end extends to the furnace tail. Both ends of each rod 21 are connected to the process tube 20. The rods 21 can be used to support a graphite boat 200, allowing the graphite boat 200 to be placed on the rods 21. The rods 21 can be made of, for example, silicon carbide (SiC).

[0067] The air intake assembly includes an air source and an air intake pipe. The air source is located outside the process pipe 20. One end of the air intake pipe is connected to the air source, and the other end is connected to the inside of the process pipe 20 to introduce process gas into the cavity. The air extraction assembly includes an air extraction pump and an exhaust pipe. The air extraction pump is located outside the process pipe 20. One end of the exhaust pipe is connected to the inside of the process pipe 20, and the other end is connected to the air extraction pump to remove gas from the cavity.

[0068] A radio frequency (RF) induction coil 30 is wound around the outer periphery of the process tube 20. The two ends of the RF induction coil 30 are the input terminal and the ground terminal, respectively, and are electrically connected to the RF power supply 40. In this way, the RF power supply 40 applies RF power to the RF induction coil 30, thereby generating a high-frequency electromagnetic field inside the process tube 20. The high-frequency electromagnetic field induces an electric field inside the process tube 20 to dissociate the fluorine-based gas into plasma, thereby achieving the cleaning of the graphite boat 200.

[0069] It should also be noted that in this embodiment, the radio frequency induction coil 30 is only wrapped around the outer periphery of a portion of the process tube 20, so that a portion of the cavity inside the process tube 20 generates an electromagnetic field. The electromagnetic field excites the process gas in the corresponding area to form plasma, so that a portion of the graphite boat 200 located in that area is cleaned.

[0070] Based on this, the semiconductor cleaning equipment 100 also includes a fixed bracket 50 and a driving device. The fixed bracket 50 is connected to the frame 10 and can move relative to the frame 10. Each turn of the wire of the radio frequency induction coil 30 is fixed on the fixed bracket 50. The driving device is used to drive the fixed bracket 50 to move along the first direction X, so as to drive the radio frequency induction coil 30 to move relative to the process tube 20 along the first direction X.

[0071] Here, the graphite boat 200 can be considered as having N boat segments arranged sequentially along the first direction X, where N is a positive integer greater than or equal to 2. For ease of description, the N boat segments, from the furnace opening to the furnace tail of the process tube 20, can be referred to as the first boat segment, ..., the Nth boat segment, respectively. The radio frequency induction coil 30 is moved by a driving device, allowing it to change position and move sequentially to the outer periphery of each boat segment, thus cleaning each boat segment in turn and achieving cleaning of the entire graphite boat 200. It should be noted that the number of boat segments N is related to the number of turns n and the length of the radio frequency induction coil 30. Specifically, the more turns n, the longer the RF induction coil 30, and the longer the portion of the graphite boat 200 surrounded by the RF induction coil 30. In this case, the smaller the number of boat segments N, the fewer times the RF induction coil 30 moves during the entire cleaning process. Conversely, the fewer turns n, the shorter the length of the RF induction coil 30, and the shorter the portion of the graphite boat 200 surrounded by the RF induction coil 30. In this case, the larger the number of boat segments N, the more times the RF induction coil 30 moves during the entire cleaning process.

[0072] Figure 4 This is a schematic diagram illustrating the operation of a semiconductor cleaning apparatus 100 provided in an embodiment of this application. Assuming the number of turns n of the radio frequency induction coil 30 is 4, and the portion surrounded by the 4 turns of the radio frequency induction coil 30 occupies 1 / 3 of the total length of the graphite boat 200 along the first direction X, then the number of boat segments N is 3. Please refer to... Figure 4An exemplary working process of the semiconductor cleaning equipment 100 in this embodiment is as follows:

[0073] Initially, the RF induction coil 30 is close to the furnace opening of the process tube 20, such as... Figure 4 As shown in Figure a, the center of the radio frequency induction coil 30 is located at 1 / 6 of the length of the graphite boat 200. The radio frequency induction coil 30 surrounds the first boat section. When the radio frequency induction coil 30 is energized, plasma is excited in the cavity corresponding to the first boat section to clean the first boat section. After a certain time t, the first boat section is cleaned and the radio frequency induction coil 30 is de-energized.

[0074] The driving device drives the fixed bracket 50 to move along the first direction X, thereby moving the RF induction coil 30 to the middle of the process tube 20, such as... Figure 4 As shown in b, the center of the radio frequency induction coil 30 is located at 1 / 2 of the length of the graphite boat 200. The radio frequency induction coil 30 surrounds the second boat section. When the radio frequency induction coil 30 is energized, plasma is excited in the cavity corresponding to the second boat section to clean the second boat section. After a certain time t, the second boat section is cleaned and the radio frequency induction coil 30 is de-energized.

[0075] The drive unit then drives the fixed bracket 50 to move along the first direction X, thereby moving the radio frequency induction coil 30 to approach the furnace tail of the process tube 20, such as... Figure 4 As shown in Figure c, the center of the radio frequency induction coil 30 is located at 5 / 6 of the length of the graphite boat 200. The radio frequency induction coil 30 surrounds the third boat section. When the radio frequency induction coil 30 is energized, plasma is excited in the cavity corresponding to the third boat section to clean the third boat section. After a certain time t, the third boat section is cleaned, and the entire graphite boat 200 is cleaned, and the cleaning process is completed.

[0076] The RF power supply 40 no longer applies RF power to the RF induction coil 30, and the air intake component introduces atmospheric air into the cavity until the cavity changes from a vacuum state to a non-vacuum state. The furnace door 22 moves relative to the process tube 20 to open the furnace opening, and the robotic arm removes the cleaned graphite boat 200 from the furnace opening.

[0077] In summary, the semiconductor cleaning equipment 100 of this embodiment is designed so that a radio frequency (RF) induction coil 30 is wrapped around the outside of a portion of the process tube 20. Only the portion of the cavity surrounded by the RF induction coil 30 can generate an electromagnetic field. Furthermore, a driving device moves the RF induction coil 30 to clean the graphite boat 200 in segments. Therefore, while ensuring the entire graphite boat 200 is thoroughly cleaned, the RF induction coil 30 in this embodiment has a relatively small length, resulting in a low resistance R. This effectively avoids prolonged cleaning time caused by excessively long RF induction coils leading to high resistance.

[0078] Thus, the semiconductor cleaning apparatus 100 of this embodiment is connected with Figure 1 Comparing the semiconductor cleaning equipment 100a shown, if the RF power P of the RF power supply 40 is the same, according to the formula for the thermal power of a resistor, P = I 2 R, it can be understood that in this embodiment, the current I on the radio frequency induction coil 30 is higher, and the concentration of plasma generated by the electromagnetic field generated by the radio frequency induction coil 30 is higher. Therefore, under the same cleaning degree of the graphite boat 200, the time required to clean the graphite boat 200 using the semiconductor cleaning equipment 100 of this embodiment is relatively shorter.

[0079] In some embodiments, the length of the RF induction coil 30 is less than one-quarter of the wavelength of the RF signal output by the RF power supply 40. For example, the RF frequency of the RF signal can be 2MHz, and the corresponding wavelength is 150m, so the length L of the RF induction coil 30 needs to be less than 37.5m. Assuming the diameter d of the RF induction coil 30 is 0.6m, according to L=πdn, and considering the certain distance between adjacent turns of the wire, the number of turns n of the RF induction coil 30 is ≤19.9.

[0080] In this embodiment, the length of the RF induction coil 30 is designed to be less than one-quarter of the wavelength of the RF signal, resulting in a smaller length. Furthermore, by designing the length of the RF induction coil 30 to be less than one-quarter of the wavelength of the RF signal, it is beneficial to avoid standing wave effects on the RF induction coil 30, ensuring that the current at various points on the RF induction coil 30 is as uniform as possible. This improves the uniformity of the electromagnetic field, thereby improving the uniformity of plasma distribution and enhancing the cleaning quality. Based on this, provided that each section of the graphite boat 200 meets the cleaning requirements, the cleaning time required using the semiconductor cleaning equipment 100 of this embodiment is short.

[0081] In this embodiment, not only can the high resistance caused by the excessive length of the RF induction coil 30 be effectively avoided, but the standing wave effect caused by the excessive length of the RF induction coil 30 can also be avoided, thus preventing the cleaning time from being prolonged.

[0082] Specifically, with Figure 1 Taking the semiconductor cleaning apparatus 100a shown and the semiconductor cleaning apparatus 100 of this embodiment as examples, both have a radio frequency of 2MHz for the radio frequency signal and the same diameter for the radio frequency induction coil 30. The wavelength of the radio frequency signal is 150m accordingly. Figure 1In the semiconductor cleaning device 100a shown, the length l of the radio frequency induction coil 30a is 1 / 3 of the wavelength of the radio frequency signal, that is, l = 50m. At this time, the radio frequency induction coil 30a can surround the entire graphite boat 200. In this embodiment, the length L of the radio frequency induction coil 30 in the semiconductor cleaning device 100 is 1 / 12 of the wavelength of the radio frequency signal, that is, L = l * 1 / 4 = 12.5m.

[0083] according to Figure 1 The semiconductor cleaning equipment 100a provided by the relevant technology has a theoretical current value of I1 on the radio frequency induction coil 30a, P = I1 2 R1, R1 = ρl / S, where ρ is resistivity and S is the cross-sectional area of ​​the RF induction coil 30a. Under ideal conditions where the electromagnetic field is uniform, the theoretical time required to clean the entire graphite boat 200 using the semiconductor cleaning device 100a is T'. However, due to the standing wave effect generated on the RF induction coil 30a, the uniformity of the electromagnetic field generated by the RF induction coil 30a is approximately 20%, indicating poor electromagnetic field uniformity. Therefore, the current at some locations on the RF induction coil 30a is only 80% of the theoretical current value. In this case, to ensure that all parts of the graphite boat 200 meet the cleaning requirements, the cleaning time needs to be doubled. Therefore, the actual time required to clean the entire graphite boat 200 using the semiconductor cleaning device 100a is T'. z 'For 2T'.

[0084] according to Figure 2 In the semiconductor cleaning apparatus 100 provided in this embodiment, the theoretical current value on the radio frequency induction coil 30 is I2, P = I2 2 R2, R2=ρL / S. Because... Figure 1 The semiconductor cleaning equipment 100a shown and Figure 2 Since the diameters of the radio frequency induction coils 30 in the semiconductor cleaning equipment 100 are the same, the cross-sectional areas of the radio frequency induction coils 30 used in both are the same. Therefore, it can be concluded that R2 = R1 * 1 / 4, and I2 = 2 * I1. Thus, the density of the plasma excited by the radio frequency induction coil 30 in this embodiment is approximately... Figure 1 The density of the plasma excited by the radio frequency induction coil 30a is 10 times that of the plasma. Correspondingly, when using the semiconductor cleaning equipment 100 for cleaning, the time T required to clean any section of the boat is significantly longer. s One-tenth of T', T s =T'*1 / 10. Furthermore, in the semiconductor cleaning equipment 100 of this embodiment, the length L of the radio frequency induction coil 30 is 1 / 12 of the wavelength of the radio frequency signal. The uniformity of the electromagnetic field generated by the radio frequency induction coil 30 is about 3%. The electromagnetic field uniformity is good, the cleaning effect is good, and the cleaning requirements can be met by cleaning any section once, so there is no need to extend the cleaning time.

[0085] It should be noted that since L = l * 1 / 4, therefore, the following is adopted. Figure 2 When the semiconductor cleaning equipment 100 is performing cleaning, the radio frequency induction coil 30 can surround one-quarter of the graphite boat 200, so the number of boat segments can be considered as 4. The radio frequency induction coil 30 moves along the first direction X to clean the first boat segment, the second boat segment, the third boat segment, and the fourth boat segment in sequence. Therefore, the time T required for the semiconductor cleaning equipment 100 to clean the entire graphite boat 200 is... z =4*T s =T'*4 / 10.

[0086] Overall, adopting Figure 2 The semiconductor cleaning equipment 100 shown in the figure requires a time T to clean the entire graphite boat 200. z It is to utilize Figure 1 The time T required for the semiconductor cleaning equipment 100a to clean the graphite boat 200 is as follows: z One-fifth of that. It is evident that the semiconductor cleaning equipment 100 of this embodiment can effectively solve the problem of long cleaning time for the graphite boat 200.

[0087] As a further optional embodiment, the length of the radio frequency induction coil 30 may be less than one-tenth of the wavelength of the radio frequency signal. By further shortening the length of the radio frequency induction coil 30, the possibility of the radio frequency induction coil 30 generating a standing wave effect can be further reduced, thereby ensuring the uniformity of the electromagnetic field, improving the cleaning quality, and thus eliminating the need to extend the cleaning time.

[0088] For example, if the radio frequency frequency of the radio frequency signal is 2MHz, and the corresponding wavelength of the radio frequency signal is 150m, the length L of the radio frequency induction coil 30 needs to be less than 15m. In this embodiment, if the diameter of the radio frequency induction coil 30 is 0.6m, according to L=πdn, the number of turns n of the radio frequency induction coil 30 ≤ 7.9, and the number of turns n of the radio frequency induction coil 30 can be, for example, 4, 5, 6, or 7.

[0089] Figure 5 This is a schematic diagram illustrating the interaction between the fixed bracket 50, the radio frequency induction coil 30, and the process tube 20 in a semiconductor cleaning apparatus 100 provided in an embodiment of this application. Please refer to... Figure 5 There is a gap between the RF induction coil 30 and the outer surface of the process tube 20. This configuration ensures that the RF induction coil 30 does not contact the outer surface of the process tube 20, thus ensuring that the RF induction coil 30 can move smoothly along the first direction X without rubbing against the process tube 20 during the movement.

[0090] In a specific example, the radial dimension Δd of the gap along the process tube 20 is greater than or equal to 10 mm and less than or equal to 50 mm. In other words, one turn of the RF induction coil 30 is concentrically arranged with the process tube 20, and the diameter D1 of the circle formed by the one turn of the RF induction coil 30 is greater than the diameter D2 of the process tube 20, and 10 mm ≤ Δd = 1 / 2(D1-D2) ≤ 50 mm.

[0091] If the gap dimension Δd is less than 10mm, the RF induction coil 30 is too close to the outer surface of the process tube 20, which can easily affect the movement of the RF induction coil 30. If the gap dimension Δd is greater than 50mm, the RF induction coil 30 is too far from the outer surface of the process tube 20, and the magnetic field strength of the electromagnetic field generated by the RF induction coil 30 in the cavity is relatively small, affecting the dissociation of the process gas. This embodiment, by designing 10mm≤Δd≤50mm, ensures both smooth movement of the RF induction coil 30 and a large magnetic field strength of the electromagnetic field generated by the RF induction coil 30 in the cavity.

[0092] In embodiments where a gap exists between the RF induction coil 30 and the outer surface of the process tube 20, it should be noted that the RF induction coil 30 should be made of a rigid material to prevent the portions of the RF induction coil 30's wires not fixed to the fixing bracket 50 from deforming and contacting the outer surface of the process tube 20. For example, the RF induction coil 30 can be made of conductive materials such as copper or silver. Among these, copper has better conductivity than materials such as brass, resulting in a copper-based RF induction coil 30 with excellent conductivity.

[0093] Please continue to refer to this. Figure 5 The fixed bracket 50 includes a metal mounting plate 51 and an insulating plate 52. The metal mounting plate 51 is connected to the frame 10 and can move relative to the frame 10 in the first direction X. The insulating plate 52 is fixedly connected to the metal mounting plate 51. Each turn of the wire of the radio frequency induction coil 30 is fixed on the side of the insulating plate 52 facing the process tube 20 to insulate and isolate the radio frequency induction coil 30 from the metal mounting plate 51.

[0094] The metal mounting plate 51 can be made of aluminum (Al) or copper. The insulating plate 52 can be made of insulating materials such as ceramic, plastic or rubber.

[0095] By combining a metal mounting plate 51 and an insulating plate 52 to form a fixed bracket 50, the fixed bracket 50 has high structural strength, which can stably fix the radio frequency induction coil 30. At the same time, each turn of the wire of the radio frequency induction coil 30 is fixed on the insulating plate 52 to avoid short circuits caused by the continuity of each turn of the wire of the radio frequency induction coil 30.

[0096] In some embodiments, please refer to Figure 2 and Figure 5 Two mounting brackets 50 may be provided, arranged opposite to each other, with the process tube 20 located between the two mounting brackets 50. Increasing the number of mounting brackets 50 increases the number of fixing points for the RF induction coil 30 on the mounting brackets 50, thereby improving the installation reliability of the RF induction coil 30. Figure 2 In the example shown, the metal mounting plates 51 of the two fixed brackets 50 are along the second direction ( Figure 2 The two ends of the plate (shown as Y) are connected to the frame 10, and the two fixed brackets 50 are arranged opposite each other and spaced apart along a third direction, wherein the third direction is perpendicular to the thickness direction of the metal mounting plate 51. Figure 2 As shown in the diagram, the two fixed supports 50 are parallel to each other, and at this time, the two fixed supports 50 are located on both sides of the process tube 20 along the third direction Z.

[0097] Of course, in other embodiments, the two fixed brackets 50 can also be arranged on both sides of the process tube 20 along the Y direction, and the metal mounting plates 51 of each fixed bracket 50 are connected to the frame 10 at both ends along the Z direction.

[0098] The following description uses the example of two fixed supports 50 arranged opposite each other along the Z direction. Those skilled in the art will obviously understand after reading the following description that the two fixed supports 50 are arranged opposite each other along the Y direction, or that four fixed supports 50 are arranged, with two arranged opposite each other along the Y direction and the other two arranged opposite each other along the Z direction.

[0099] In some embodiments of this application, the frame 10 is provided with four slide rails extending along a first direction X. In this embodiment, each metal mounting plate 51 is provided with a slider 55 at both ends along a second direction, and each slider 55 is slidably engaged with one slide rail.

[0100] The slide rail can be a groove formed on the frame 10, which can be manufactured by machining. Alternatively, in an alternative embodiment, a guide rail 70 can be fixedly installed on the frame 10, in which case the slide rail is the track of the guide rail 70, wherein the guide rail 70 can be obtained by purchasing.

[0101] By setting up slide rails and sliders 55, the sliding engagement between sliders 55 and slide rails can serve as a guide, guiding the fixed brackets 50 to move the radio frequency induction coil 30 along the first direction X. It should be noted that in this embodiment, the driving device can be connected to one of the multiple fixed brackets 50. The driving device drives one fixed bracket 50 to move, and the sliders 55 on the other fixed brackets 50 can slide on the corresponding slide rails. At this time, multiple fixed brackets 50 drive the radio frequency induction coil 30 to move, further ensuring that the radio frequency induction coil 30 can move smoothly and steadily.

[0102] Please continue to refer to this. Figures 3 to 5 The semiconductor cleaning equipment 100 also includes a first connector 42 and a second connector 43 mounted on a fixed bracket 50. The first connector 42 is connected to the input terminal, and the second connector 43 is connected to the ground terminal. The first connector 42 and the second connector 43 are electrically connected to the RF power supply 40 via flexible cables 41. Specifically, one end of the metal mounting plate 51 protrudes towards the process tube 20, forming a flange 511. The first connector 42 and the second connector 43 can be mounted on the flange 511.

[0103] Therefore, the RF power supply 40 applies RF power to the RF induction coil 30 through an intermediate medium (i.e., the first connector 42 and the second connector 43). Furthermore, by designing the first connector 42 and the second connector 43 to be mounted on the fixed bracket 50, the first connector 42 and the second connector 43 can easily move with the fixed bracket 50 to change positions, ensuring that the RF induction coil 30 can move smoothly to achieve segmented cleaning. In addition, by connecting the connectors and the RF power supply 40 through a flexible cable 41, the flexible cable 41 can extend and deform during the movement of the fixed bracket 50 by the driving device, ensuring that the RF induction coil 30 can move smoothly.

[0104] The first connector 42 and the second connector 43 can be any one of the following: N-type RF connector, NH-type RF connector, and LC RF connector.

[0105] The connection between the first connector 42 and the input terminal, and between the second connector 43 and the ground terminal, can be achieved by snap-fit, soldering, screwing, or other connection techniques in the art. Taking screwing as an example, the input terminal can be fixed to the first connector 42 by screws.

[0106] In an embodiment where two fixed supports 50 are provided, and the two fixed supports 50 are arranged opposite each other along a third direction Z, such as... Figure 5 As shown, the first connector 42 and the second connector 43 can be mounted on the same fixed bracket 50. This allows the input and ground terminals of the RF induction coil 30 to be routed to the same side of the process tube 20, avoiding redundancy in the RF induction coil 30 and minimizing contact between the wires and the outer surface of the process tube 20. Using this example, the RF power supply 40 can be positioned close to the fixed bracket 50 with the connectors, allowing it to be easily connected to the first connector 42 and the second connector 43 via a flexible cable 41. This ensures the RF induction coil 30 can move smoothly while keeping the flexible cable 41 as short as possible to prevent excessive redundancy.

[0107] The following section will describe in detail the specific structure of each turn of the RF induction coil 30 being fixed on the insulating plate 52, with reference to the accompanying drawings.

[0108] Figure 6 This is a partial schematic diagram showing the cooperation between the fixed bracket 50 and the radio frequency induction coil 30 in a semiconductor cleaning device 100 provided in an embodiment of this application. Please refer to... Figure 6 Multiple limiting spaces are formed on the side of the insulating plate 52 facing the process tube 20. Each turn of the RF induction coil 30 is correspondingly inserted into a limiting space, so that the displacement of each turn of the wire along the thickness direction Z of the insulating plate 52 is restricted, so as to prevent the wire from deforming under the action of gravity and sticking to the outer surface of the process tube 20, so as to ensure that the RF induction coil 30 can move smoothly.

[0109] In one possible embodiment, the insulating plate 52 may protrude from the metal mounting plate 51. In other words, the side of the insulating plate 52 facing the process tube 20 is closer to the process tube 20 than the side of the metal mounting plate 51 facing the process tube 20. Based on this embodiment, a plurality of slots are recessed on the side of the insulating plate 52 facing the process tube 20. The slots extend along the second direction and penetrate the top and bottom surfaces of the insulating plate 52. The plurality of slots are arranged sequentially at intervals along the first direction. The slots serve as limiting spaces, and each turn of wire can be correspondingly clamped into one slot.

[0110] In another possible embodiment, the metal mounting plate 51 is recessed in a direction away from the process tube 20 to form a groove, and the insulating plate 52 is located within the groove, with the thickness of the insulating plate 52 equal to the depth of the groove. That is, the side of the insulating plate 52 facing the process tube 20 is coplanar and flush with the side of the metal mounting plate 51 facing the process tube 20, and the insulating plate 52 does not protrude from the side of the metal mounting plate 51 facing the process tube 20. Compared to the embodiment where the insulating plate 52 protrudes from the side of the metal mounting plate 51 facing the process tube 20, this embodiment is designed so that the insulating plate 52 does not occupy the space between the side of the metal mounting plate 51 facing the process tube 20 and the process tube 20. If the distance between the two metal mounting plates 51 along the third direction Y is the same in both possible embodiments, then in this embodiment, the gap between the RF induction coil 30 and the outer surface of the process tube 20 can be larger to reduce the possibility of the RF induction coil 30 contacting the outer surface of the process tube 20.

[0111] Based on this embodiment, such as Figure 6As shown, the fixed bracket 50 may further include multiple limiting plates 53. Each limiting plate 53 has connecting plates 54 connected to both ends along the first direction. The connecting plates 54 are fixedly connected to the side of the insulating plate 52 facing the process tube 20. The limiting plates 53 and the side of the insulating plate 52 facing the process tube 20 together form a limiting space. An exemplary process for fixing the wire to the insulating plate 52 in this embodiment is as follows: attach the wire to a suitable position on the side of the insulating plate 52 facing the process tube 20; attach the connecting plates 54 at both ends of one limiting plate 53 to the insulating plate 52, and position the two connecting plates 54 on both sides of the wire along the first direction; connect the two connecting plates 54 to the insulating plate 52.

[0112] In some embodiments, the limiting plate 53 may also be configured such that one end is connected to the insulating plate 52 via the connecting plate 54, the limiting plate 53 is elastic, and the other end of the limiting plate 53 is a free end. An exemplary process for fixing the wire to the insulating plate 52 in this embodiment is as follows: pull the other end of the limiting plate 53 so that the other end of the limiting plate 53 moves away from the insulating plate 52 to form a gap between it and the side of the insulating plate 52 facing the process tube 20; insert the wire through the gap into the limiting space enclosed by the limiting plate 53 and the insulating plate 52; release the other end of the limiting plate 53, the limiting plate 53 returns to its original deformation, and the other end of the limiting plate 53 abuts against the side of the insulating plate 52 facing the process tube 20, and the wire is clamped in the limiting space.

[0113] The aforementioned limiting plate 53 is not limited to... Figure 6 In some feasible implementations of the flat plate structure shown, the limiting plate 53 can also be an arc-shaped plate, which surrounds the outside of the conductor.

[0114] As disclosed herein, the connecting plate 54 and the insulating plate 52 can be connected by snap-fit, welding, bonding, or screwing. Similarly, the insulating plate 52 can also be connected to the mounting plate using snap-fit, welding, bonding, or screwing techniques. Taking screwing as an example, screws can be used to connect the connecting plate 54 to the insulating plate 52, and the insulating plate 52 to the mounting plate. Optionally, the screws can be made of insulating materials such as ceramic or plastic to prevent short circuits caused by the two turns of wire conducting through the screw and the metal mounting plate 51. Of course, in some embodiments of this application, the screws can also be made of metal. In this example, to prevent short circuits caused by the two turns of wire conducting through the screw and the metal mounting plate 51, the distance between any screw and the wire along the first direction X should be greater than 50 mm.

[0115] In other embodiments, the side of the insulating plate 52 facing the process tube 20 may also be provided with multiple sets of limiting components. Each set of limiting components includes a first protrusion and a second protrusion arranged opposite to each other along the first direction X. In this way, the first protrusion, the second protrusion and the insulating plate 52 together form a limiting space for clamping the wire, and the wire is clamped between the first protrusion and the second protrusion.

[0116] The specific implementation of the drive device will be described in detail below with reference to the accompanying drawings. Figure 7 for Figure 2 A partial enlarged view of point A in the semiconductor cleaning equipment 100 shown. Figure 8 for Figure 2 This is a magnified view of point B in the semiconductor cleaning apparatus 100 shown. Please refer to... Figure 2 and Figure 7 The drive device includes a drive motor 60 and a transmission device. The drive motor 60 is mounted on the frame 10, and the transmission device is used to convert the rotational power of the drive motor 60 into linear power and transmit it to the metal mounting plate 51 so as to drive the metal mounting plate 51 to move along the first direction.

[0117] Exemplarily, the transmission device includes a synchronous shaft, a driving pulley 63, a driven pulley, and a conveyor belt 61. The rotation axis of the synchronous shaft extends Z-axis along a third direction. One end of the synchronous shaft is connected to the motor shaft of the drive motor 60. The driving pulley 63 is mounted on the other end of the synchronous shaft. The driven pulley is rotatably connected to the frame 10, and its rotation axis is parallel to the rotation axis of the synchronous shaft. The conveyor belt 61 is wound between the driving pulley 63 and the driven pulley. Furthermore, a transmission component 611 is fixedly mounted on the conveyor belt 61 and is fixedly connected to the metal mounting plate 51. Specifically, the transmission device may include a rotating shaft extending Z-axis along a third direction. One end of the rotating shaft is rotatably connected to the frame 10, and the driven pulley is mounted on the other end of the rotating shaft.

[0118] In this way, the drive motor 60 runs, the motor shaft rotates, the synchronous shaft rotates around the rotation axis, the drive pulley 63 also rotates, which in turn drives the conveyor belt 61 and the transmission component 611 to move along the first direction X, and the metal mounting plate 51 connected to the transmission component 611 drives the radio frequency induction coil 30 to move.

[0119] It is understandable that the fixed connection between the transmission component 611 and the metal mounting plate 51 should be interpreted broadly. For example, it can be understood that the transmission component 611 is directly connected to the metal mounting plate 51, or that the transmission component 611 is indirectly connected to the metal mounting plate 51. Figure 8 In the specific example shown, where sliders 55 are provided at both ends of the metal mounting plate 51 along the second direction, the transmission member 611 can specifically be a plate-shaped structure, and the transmission member 611 can be connected to the sliders 55. Thus, when the transmission member 611 moves, the sliders 55 move accordingly, thereby driving the metal mounting plate 51 connected to it to move.

[0120] The transmission component 611 can be screwed to the conveyor belt 61, or it can be connected to the conveyor belt 61 by welding or other connection methods. Please continue to refer to [the relevant documentation]. Figure 8In an embodiment where the transmission component 611 and the conveyor belt 61 are screwed together, the transmission device may further include a pressure plate 612. The pressure plate 612 faces the transmission component 611, and together they clamp a portion of the conveyor belt 61. The screw passes through the pressure plate 612 and the conveyor belt 61 in sequence, then extends into the interior of the transmission component 611 and is threadedly connected to it. Thus, the pressure plate 612 provides a mounting position for the screw.

[0121] Furthermore, since the graphite boat 200 is relatively long, typically up to 1.5m, the length of the process tube 20 along the first direction is usually greater than 1.5m, resulting in a large dimension of the semiconductor cleaning equipment 100 along the first direction. In this embodiment, the transmission device is a belt drive mechanism. Compared with a gear and rack mechanism, the belt drive mechanism has the advantage of a larger center distance between the two shafts, making it suitable for the semiconductor cleaning equipment 100 to achieve smooth transmission.

[0122] Please continue to refer to this. Figure 7 The semiconductor cleaning equipment 100 also includes a connecting support 66, a motor support 65, and a supporting support 64. The connecting support 66 is in the shape of a "┐" and is fixedly connected to the frame 10. One end of the supporting support 64 is connected to the connecting support 66, and the other end is connected to the motor support 65. The drive motor 60 is fixedly mounted on the motor support 65. With this arrangement, the frame 10 provides support for the connecting support 66, the motor support 65, and the supporting support 64, and the motor support 65 provides support for the drive motor 60.

[0123] In this embodiment, the support 64 is provided with a first through hole and a second through hole. The central axes of the first and second through holes are collinear and extend along the third direction Z. The synchronous shaft passes through the first and second through holes, and the other end of the synchronous shaft passes through the second through hole and connects to the drive pulley 63. Bearings are sleeved between the synchronous shaft and the walls of the first and second through holes. In this way, the support 64 can support the synchronous shaft while ensuring that the synchronous shaft can rotate, so as to ensure that the transmission device can realize transmission.

[0124] Please continue to refer to this. Figure 2 The frame 10 includes a main frame 11 and a partition frame 12. The main frame 11 is a cuboid frame structure, and the partition frame 12 is a rectangular frame structure. The partition frame 12 is set inside the main frame 11 to divide the main frame 11 into a first space and a second space. The process tube 20 is located in the first space, and the connecting support 66, the motor support 65 and the support support 64 are all located in the second space.

[0125] With this arrangement, the process tube 20 is installed in the first space, and the drive motor 60 and transmission device are installed in the second space. Sufficient installation space is reserved for the drive motor 60, transmission device, connecting support 66, motor support 65 and support support 64, which helps to avoid interference between these components and the process tube 20 during installation.

[0126] Figure 9 This is a schematic diagram illustrating a cleaning method provided in an embodiment of this application. Please refer to [link / reference]. Figure 9 This application also provides a cleaning method applied to the semiconductor cleaning equipment 100 described in the above embodiments of the present invention to clean the graphite boat 200. The cleaning method specifically includes the following steps:

[0127] S10, the graphite boat to be cleaned is placed into the cavity of the process tube; wherein, the graphite boat has multiple boat segments arranged sequentially along the first direction.

[0128] As mentioned above, the number of boat segments is related to the number of turns n of the RF induction coil 30 and the length of the RF induction coil 30. When the RF induction coil 30 can surround the outer periphery of one-third of the graphite boat, the corresponding number of boat segments is three. This embodiment will not list them all here.

[0129] S20, boat section cleaning step: The control drive device drives the fixed bracket to move relative to the process tube along the first direction, so as to move the radio frequency induction coil along the first direction to the outer periphery of one of the boat sections, load radio frequency power onto the radio frequency induction coil, so that the process gas in the cavity forms plasma, and maintain the position of the radio frequency induction coil for a preset time, so that the boat section is cleaned.

[0130] In this step, the radio frequency induction coil is held in the corresponding position for a preset time, and radio frequency power is also applied to the radio frequency induction coil during the preset time, so that plasma is generated in a part of the cavity surrounded by the radio frequency induction coil.

[0131] Here, a timer is used to determine whether a preset duration has been reached. For example, the specific process of S20 can be as follows: i) control the driving device to drive the fixed bracket to move relative to the process tube along a first direction, so as to move the radio frequency induction coil along the first direction to the outer periphery of one of the boat segments; ii) stop driving the fixed bracket to maintain the position of the radio frequency induction coil and start timing; iii) apply radio frequency power to the radio frequency induction coil, so that the process gas in the cavity forms plasma; iv) when the preset duration is reached, the boat segment is cleaned.

[0132] S30, return to the boat segment cleaning step to clean another boat segment, until all boat segments have been cleaned.

[0133] When the semiconductor cleaning equipment 100 uses this cleaning method, the length of the radio frequency induction coil 30 is relatively small, and the radio frequency induction coil 30 is moved by a driving device to achieve segmented cleaning of the graphite boat 200. In this way, the resistance R on the radio frequency induction coil 30 is low and the current I is high. The concentration of plasma excited by the electromagnetic field generated by the radio frequency induction coil 30 is higher, which can effectively avoid the cleaning time being prolonged due to the high resistance caused by the excessive length of the radio frequency induction coil 30, thus helping to shorten the cleaning time.

[0134] In some embodiments, the cleaning method further includes step S40 between steps S20 and S30.

[0135] S40, stop applying RF power to the RF induction coil.

[0136] With this design, after cleaning one segment of the boat, the RF induction coil stops being loaded with RF power as it moves to surround another segment. RF power is only loaded again when the RF induction coil has moved to surround the other segment.

[0137] In this way, on the one hand, it is beneficial to save energy consumption, and on the other hand, it is beneficial to avoid the process gas in the cavity from being excited to form plasma during the movement of the radio frequency induction coil, that is, to avoid cleaning the graphite boat during the movement of the radio frequency induction coil, so that the starting point of cleaning each boat segment is as close as possible to the point after the boat segment is surrounded by the radio frequency induction coil, so that the time required to clean each boat segment is more accurate.

[0138] It is understandable that the order in which the boat sections are cleaned in step S30 is not limited.

[0139] In one example, the RF induction coil 30 initially surrounds the outer periphery of a segment closest to the furnace opening of the process tube 20. Based on this, the cleaning sequence of each segment in step S30 is specifically as follows: cleaning each segment sequentially from the furnace opening of the process tube 20 to the furnace tail of the process tube 20.

[0140] Specifically, in an embodiment where the number of boat segments N is 3, and the three boat segments are referred to as the first boat segment, the second boat segment, and the third boat segment from the furnace mouth to the furnace tail of the process tube 20, the cleaning order of each boat segment is as follows: first clean the first boat segment, then clean the second boat segment, and finally clean the third boat segment.

[0141] Understandably, a specific implementation of this cleaning method may include the following steps.

[0142] Step 1: Place the graphite boat to be cleaned into the cavity of the process tube.

[0143] Step 2: Control the drive device to drive the fixed bracket to move relative to the process tube along the first direction, so as to drive the radio frequency induction coil to move along the first direction, so that the center of the radio frequency induction coil moves to 1 / 6 of the length of the graphite boat, and the radio frequency induction coil surrounds the first boat section; apply radio frequency power to the radio frequency induction coil, so that the process gas in the cavity forms plasma, and maintain the position of the radio frequency induction coil for a preset time, so that the first boat section is cleaned.

[0144] Step 3: Stop applying radio frequency power to the radio frequency induction coil.

[0145] Step 4: Control the drive device to drive the fixed bracket to move relative to the process tube along the first direction, so as to drive the radio frequency induction coil to move along the first direction, so that the center of the radio frequency induction coil moves to 1 / 2 of the length of the graphite boat, and the radio frequency induction coil surrounds the second boat section; apply radio frequency power to the radio frequency induction coil, so that the process gas in the cavity forms plasma, and maintain the position of the radio frequency induction coil for a preset time, so that the second boat section is cleaned.

[0146] Step 5: Stop applying radio frequency power to the radio frequency induction coil.

[0147] Step 6: Control the drive device to drive the fixed bracket to move relative to the process tube along the first direction, so as to drive the radio frequency induction coil to move along the first direction, so that the center of the radio frequency induction coil moves to 5 / 6 of the length of the graphite boat, and the radio frequency induction coil surrounds the third boat section; apply radio frequency power to the radio frequency induction coil, so that the process gas in the cavity forms plasma, and maintain the position of the radio frequency induction coil for a preset time, so that the third boat section is cleaned.

[0148] In another example, the RF induction coil 30 initially surrounds the outer periphery of a boat section closest to the furnace tail of the process tube 20. Based on this, the specific order of cleaning each boat section in step S30 is as follows: cleaning each boat section sequentially from the furnace tail of the process tube 20 to the furnace opening of the process tube 20.

[0149] Specifically, in an embodiment where the number of boat segments N is 3, and the three boat segments are referred to as the first boat segment, the second boat segment, and the third boat segment from the furnace mouth to the furnace tail of the process tube 20, the cleaning order of each boat segment is as follows: first clean the third boat segment, then clean the second boat segment, and finally clean the first boat segment.

[0150] Using this cleaning method, the direction of movement of the radio frequency induction coil 30 does not need to be changed while ensuring that each section of the boat can be cleaned. This helps to avoid the radio frequency induction coil 30 moving back and forth along the first direction, which would prolong the cleaning time and ensure that the cleaning time is minimized, thus improving the cleaning efficiency.

[0151] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A semiconductor cleaning device, characterized in that, include: frame; The process tube has an internal cavity for accommodating the graphite boat to be cleaned; A fixed bracket, connected to the frame and movable relative to the frame; A radio frequency induction coil is wound around the outer periphery of the process tube, and each turn of the wire of the radio frequency induction coil is fixed on the fixed bracket. The radio frequency induction coil is used to cause the process gas in the process tube to form plasma. A driving device is used to drive the fixed bracket to move along a first direction, thereby causing the radio frequency induction coil to move relative to the process tube along the first direction; wherein, the first direction is parallel to the length direction of the process tube. The length of the radio frequency induction coil is less than one-quarter of the wavelength of the radio frequency signal applied to the radio frequency induction coil, and the length of the graphite boat surrounded by the radio frequency induction coil is less than the length of the graphite boat.

2. The semiconductor cleaning equipment according to claim 1, characterized in that, The length of the radio frequency induction coil is less than one-tenth of the wavelength of the radio frequency signal.

3. The semiconductor cleaning equipment according to claim 1, characterized in that, It also includes an RF power supply disposed outside the process tube, the RF power supply being used to output RF signals; The two ends of the radio frequency induction coil are the input end and the ground end, respectively; the semiconductor cleaning equipment also includes a first connector and a second connector installed on the fixed bracket, the first connector is connected to the input end, the second connector is connected to the ground end, and the first connector and the second connector are electrically connected to the radio frequency power supply respectively through flexible cables.

4. The semiconductor cleaning equipment according to claim 3, characterized in that, Two fixed supports are provided, and the two fixed supports are arranged opposite to each other, with the process tube located between the two fixed supports; The first connector and the second connector are mounted on the same fixed bracket.

5. The semiconductor cleaning equipment according to claim 1, characterized in that, There is a gap between the radio frequency induction coil and the outer surface of the process tube.

6. The semiconductor cleaning equipment according to claim 5, characterized in that, The gap along the radial dimension of the process tube is greater than or equal to 10 mm and less than or equal to 50 mm.

7. The semiconductor cleaning apparatus according to any one of claims 1 to 6, characterized in that, The fixed bracket includes a metal mounting plate and an insulating plate. The insulating plate is fixedly connected to the metal mounting plate. Each turn of the wire of the radio frequency induction coil is fixed to the side of the insulating plate facing the process tube to insulate and isolate the radio frequency induction coil from the metal mounting plate.

8. The semiconductor cleaning equipment according to claim 7, characterized in that, The insulating plate has multiple limiting spaces on the side facing the process tube. Each turn of the RF induction coil is inserted into one of the limiting spaces, thereby restricting the displacement of each turn of the wire along the thickness direction of the insulating plate.

9. The semiconductor cleaning equipment according to claim 8, characterized in that, The metal mounting plate is recessed in a direction away from the process pipe to form a groove, the insulating plate is located within the groove, and the thickness of the insulating plate is equal to the depth of the groove; and / or, The fixed bracket also includes multiple limiting plates. At least one end of the limiting plate along the first direction is fixedly connected to the side of the insulating plate facing the process tube. The limiting plate and the insulating plate together enclose a limiting space.

10. The semiconductor cleaning equipment according to claim 7, characterized in that, The frame is provided with multiple slide rails that extend along the first direction; the metal mounting plate is provided with sliders at both ends along the second direction, and each slider is slidably engaged with one of the slide rails; wherein the second direction is perpendicular to the first direction and the thickness direction of the metal mounting plate.

11. The semiconductor cleaning equipment according to claim 7, characterized in that, The driving device includes a drive motor and a transmission device. The drive motor is mounted on the frame, and the transmission device is used to convert the rotational power of the drive motor into linear power and transmit it to the metal mounting plate to drive the metal mounting plate to move along the first direction.

12. A cleaning method, characterized in that, The semiconductor cleaning apparatus according to any one of claims 1 to 11, the cleaning method comprising: The graphite boat to be cleaned is placed into the cavity of the process tube; wherein, the graphite boat has multiple boat segments arranged sequentially along a first direction; In the boat section cleaning step, the control drive device drives the fixed bracket to move relative to the process tube along the first direction, so as to move the radio frequency induction coil along the first direction to surround the outer periphery of one of the boat sections, load radio frequency power onto the radio frequency induction coil, so that the process gas in the cavity forms plasma, and maintain the position of the radio frequency induction coil for a preset time, so that the boat section is cleaned. Return to the segment cleaning step to clean another segment until all segments have been cleaned.

13. The cleaning method according to claim 12, characterized in that, The radio frequency induction coil is initially positioned around the outer periphery of a boat segment near the furnace opening of the process tube; during the cleaning of all boat segments, each boat segment is cleaned sequentially from the furnace opening to the furnace tail of the process tube; or, The radio frequency induction coil is initially positioned around the outer periphery of a boat section near the furnace tail of the process tube; during the cleaning of all the boat sections, each boat section is cleaned sequentially from the furnace tail of the process tube to the furnace mouth of the process tube.

14. The cleaning method according to claim 12, characterized in that, After the boat section cleaning step and before returning to the boat section cleaning step, the cleaning method further includes: Stop applying radio frequency power to the radio frequency induction coil.

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