Pecvd reaction chamber and pecvd coating and cleaning method

Abstract

The application discloses a PECVD reaction cavity and a PECVD film forming and cleaning method. The PECVD reaction cavity comprises an inner cavity and an outer cavity, a radio frequency power supply and a vacuum module. The inner cavity comprises an inner cavity door, a PECVD film forming module, a cleaning module, vertically and parallelly arranged heating plates and radio frequency electrode plates. When receiving a film forming instruction, the film forming module controls vacuumizing and controls a driving door plate to move to a position for opening a corresponding door hole, controls film forming gas to enter the inner cavity and opens the radio frequency power supply to make the film forming gas dissociate into plasma to deposit a film layer with a preset thickness on a silicon wafer when a film forming pressure is reached. After the film forming module continuously operates for a first predetermined period or receives a cleaning instruction, the cleaning module controls the driving door plate to move to a position for closing the corresponding door hole, controls cleaning gas to enter the inner cavity and clean the film deposited on each inner wall of the inner cavity after dissociating into plasma, controls the driving door plate to move to the position for opening the corresponding door hole after continuously operating for a second predetermined period and performs cleaning on each inner wall of the inner and outer cavities for a third predetermined period.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic manufacturing, and in particular to a PECVD reaction chamber and a PECVD coating and cleaning method. Background Technology

[0002] In the manufacturing of heterojunction solar cells, PECVD (Plasma Enhanced Chemical Vapor Deposition) equipment is used to deposit P-type amorphous silicon / microcrystalline silicon, N-type amorphous silicon / microcrystalline silicon, and intrinsic I-type amorphous silicon thin films on silicon wafers.

[0003] Current PECVD equipment typically employs a horizontal transport method (referred to as "horizontal PECVD equipment"), where the carrier plate is transported horizontally and the silicon wafer is placed horizontally within the carrier plate by gravity. To meet the industry's ever-increasing demand for cell production capacity, some manufacturers have introduced vertical PECVD equipment. This equipment includes a reaction chamber and an RF power supply. The reaction chamber comprises multiple vertically parallel RF electrode plates, multiple vertically parallel heating plates spaced apart from the RF electrode plates, and a transport device. Vertical PECVD equipment can significantly increase solar cell production capacity without increasing costs. However, the film uniformity of this vertical equipment is significantly affected by the vertically parallel RF electrode plates, with film non-uniformity reaching approximately 15%, directly impacting the performance and application scenarios of PECVD-fabricated devices.

[0004] Furthermore, when a vertical PECVD equipment continuously runs the coating process, thin films will also be deposited on the inner wall of the chamber. Once these films reach a sufficient thickness, they may detach due to disturbances such as temperature and plasma or stress. The detached particles inside the chamber will also affect the film quality. Therefore, the PECVD chamber needs to be cleaned after performing multiple deposition processes.

[0005] In existing technologies, NF3 is used as a cleaning gas to clean the PECVD chamber. NF3 can be directly introduced into the PECVD chamber and dissociated into fluorine radicals by the radio frequency voltage within the chamber. These fluorine radicals then react with reaction residues in the PECVD chamber to generate volatile products, achieving a cleaning effect. Alternatively, some or all of the NF3 cleaning gas can be introduced into a remote plasma source (RPS) to dissociate into fluorine radicals, which are then introduced into the PECVD chamber to directly react with reaction residues and generate volatile products, thus achieving cleaning. However, when cleaning with NF3, the cleaning speed is faster in the upper part of the chamber and slower in the lower part, affecting the cleaning uniformity and speed.

[0006] Therefore, how to provide a PECVD reaction chamber and a PECVD coating and cleaning method to effectively improve coating uniformity and cleaning uniformity, increase cleaning speed, and reduce cleaning time has become a technical problem that the industry urgently needs to solve. Summary of the Invention

[0007] To address the aforementioned problems of the prior art, this invention proposes a PECVD reaction chamber, comprising an outer cavity, an inner cavity, a radio frequency power supply, and a vacuum module. The inner cavity is disposed within and communicates with the outer cavity, and the inner cavity includes: The inner cavity door includes a first cavity door and a second cavity door disposed between two inner cavity walls and opposite to each other. Each of the first cavity door and the second cavity door includes multiple door openings, multiple door panels, and a driving device for driving the multiple door panels to open or close the corresponding door openings. Multiple vertically parallel radio frequency electrode plates are arranged therein, and the radio frequency electrode plates are connected to the radio frequency power supply; Multiple heating plates are arranged vertically in parallel therein, and the heating plates are spaced apart from multiple radio frequency electrode plates and grounded; A transfer device, which is disposed at the bottom of the inner cavity, is used to transfer multiple vertically parallel carrier plates loaded with silicon wafers through the first cavity door or the second cavity door to the inner cavity or to the PECVD reaction chamber on both sides of the multiple heating plates. The PECVD film deposition module, upon receiving a film deposition command, controls the vacuum module to evacuate the outer and inner cavities, and sends a first trigger signal to the drive device of the inner cavity door to drive the door plate to move to the position corresponding to the opening of the corresponding doorway. It also controls the entry of film deposition gas into the inner cavity and activates the radio frequency power supply when the inner cavity pressure reaches the film deposition pressure, causing the film deposition gas to dissociate into plasma via the radio frequency voltage between the radio frequency electrode plate and the heating plate, thereby depositing a film layer of a preset thickness on the silicon wafer. Furthermore, it drives the transmission device to transport the carrier plate carrying the deposited silicon wafer out of the PECVD reaction chamber. The cleaning module is used to send a second trigger signal to the drive device of the inner cavity door to drive the door plate to move to the position of closing the corresponding door opening after the PECVD film deposition module has been running for a first predetermined period of time or after receiving a cleaning command. It is also used to control the cleaning gas to enter the inner cavity and clean the film deposited on each inner wall of the inner cavity after dissociating into plasma. When the cleaning continues for a second predetermined period of time, it sends a third trigger signal to the drive device of the inner cavity door to drive the door plate to move to the position of opening the corresponding door opening, and cleans each inner wall of the inner cavity and each inner wall of the outer cavity for a third predetermined period of time.

[0008] In one embodiment, the first predetermined time period is 20-200 hours, the second predetermined time period is 1000-30000 seconds, and the third predetermined time period is 100-3000 seconds.

[0009] In one embodiment, the film-forming gas includes SiH4 and H2, and also includes CO2, CH4, NO2, PH3 or B2H6, the film-forming pressure is 0.1-10 mbar, the predetermined thickness is 5-50 nm, and the film layer includes an intrinsic amorphous silicon layer, an N-type amorphous silicon / microcrystalline silicon layer, and a P-type amorphous silicon / microcrystalline silicon layer.

[0010] In one embodiment, the cleaning gas includes NF3 and Ar, with an NF3 flow rate of 1-100 slm, an Ar flow rate of 0-50 slm, and a cleaning pressure of 0.1-10 mbar. The NF3 is dissociated into plasma by the radio frequency voltage between the radio frequency electrode plate and the heating plate.

[0011] In one embodiment, the PECVD reaction chamber further includes a remote plasma source, and the cleaning gas is partly or entirely F-containing cleaning plasma provided by the remote plasma source.

[0012] The present invention also provides a PECVD film formation and cleaning method, which is carried out through the above-mentioned PECVD reaction chamber and includes the following steps: Step 1: The PECVD film deposition module determines whether a film deposition command has been received. If so, multiple vertically parallel carriers loaded with silicon wafers are transferred into the inner cavity via the first or second cavity door through the transfer device located at the bottom of the inner cavity. Step 2: The PECVD film formation module controls the vacuum module to evacuate the outer and inner cavities of the PECVD reaction chamber, and sends a first trigger signal to the drive device of the inner cavity door to drive the door plate to move to the position where the corresponding door opening is located. Step 3: The PECVD film deposition module controls the film deposition gas to enter the inner cavity and turns on the radio frequency power supply when the pressure in the inner cavity reaches the film deposition pressure. The film deposition gas is then dissociated into plasma by the radio frequency voltage between the radio frequency electrode plate and the heating plate, thereby depositing a film layer of a preset thickness on the silicon wafer. Step 4: The transmission device transports multiple carrier plates loaded with silicon wafers after film formation out of the PECVD reaction chamber through the first or second chamber door on both sides of the multiple heating plates. Step 5: The PECVD film formation module determines whether its continuous operation has exceeded the first predetermined time period. If so, it generates and outputs a cleaning command; otherwise, it returns to step 1. Step six: The cleaning module determines whether a cleaning command has been received. If so, it sends a second trigger signal to the drive device of the inner door to drive the door panel to move to the position where the corresponding door opening is closed; and Step 7: The cleaning module controls the cleaning gas to enter the inner cavity and cleans the thin film deposited on each inner wall of the inner cavity after dissociating into plasma. During the second predetermined cleaning period, a third trigger signal is sent to the drive device of the inner cavity door to drive the door panel to move to the position of opening the corresponding door opening, and the inner walls of the inner cavity and the inner walls of the outer cavity are cleaned for a third predetermined period.

[0013] In one embodiment, the first predetermined time period in step five is 20-200 hours, and the second and third predetermined time periods in step seven are 1000-30000 seconds and 100-3000 seconds, respectively.

[0014] In one embodiment, the film-forming gas in step three includes SiH4 and H2, and also includes CO2, CH4, NO2, PH3 or B2H6. The film-forming pressure is 0.2-10 mbar, the predetermined thickness is 5-50 nm, and the film layer includes an intrinsic amorphous silicon layer, an N-type amorphous silicon / microcrystalline silicon layer, and a P-type amorphous silicon / microcrystalline silicon layer.

[0015] In one embodiment, the cleaning gas in step seven includes NF3 and Ar, with an NF3 flow rate of 1-100 slm, an Ar flow rate of 0-50 slm, and a cleaning pressure of 0.1-10 mbar. The NF3 is dissociated into plasma by the radio frequency voltage between the radio frequency electrode plate and the heating plate.

[0016] In one embodiment, the cleaning gas in step seven is partly or entirely F-containing cleaning plasma provided by a remote plasma source.

[0017] Compared to existing vertical PECVD equipment which suffers from poor film uniformity and cleaning uniformity, the PECVD reaction chamber of this invention includes an outer chamber, an inner chamber, an RF power supply, and a vacuum module. The inner chamber is located within and connected to the outer chamber. The inner chamber includes an inner chamber door, multiple vertically parallel RF electrode plates connected to the RF power supply, multiple vertically parallel heating plates spaced apart from and grounded within the inner chamber, a transmission device, a PECVD film formation module, and a cleaning module. The inner chamber door includes a first chamber door and a second chamber door located between two opposing inner chamber walls. Each of the first and second chamber doors includes multiple openings, multiple door panels, and a driving device for opening or closing the corresponding openings of the door panels. The transmission device is located at the bottom of the inner chamber and is used to pass multiple vertically parallel carriers loaded with silicon wafers through the first or second chamber door to the inner chamber or out of the PECVD reaction chamber via the heating plates on both sides. When the PECVD film formation module receives a film formation command, it controls the vacuum module to apply pressure to the outer chamber. The system evacuates the inner cavity and sends a first trigger signal to the drive device of the inner cavity door to drive the door plate to move to the position corresponding to the opening of the corresponding doorway. It also controls the entry of film-forming gas into the inner cavity and activates the radio frequency power supply when the inner cavity pressure reaches the film-forming pressure. This allows the film-forming gas to dissociate into plasma via the radio frequency voltage between the radio frequency electrode plate and the heating plate, thereby depositing a film layer of a predetermined thickness on the silicon wafer. Furthermore, it drives the transmission device to transport the carrier plate carrying the film-formed silicon wafer out of the PECVD reaction chamber. The cleaning module is used in the P… The ECVD film deposition module continuously operates for a first predetermined period of time, or upon receiving a cleaning command, sends a second trigger signal to the drive device of the inner cavity door to drive the door plate to move to a position where the corresponding door opening is closed. This also controls the entry of cleaning gas into the inner cavity, which, after dissociating into plasma, cleans the thin films deposited on the inner walls of the inner cavity. Furthermore, during a second predetermined period of cleaning, a third trigger signal is sent to the drive device of the inner cavity door to drive the door plate to move to a position where the corresponding door opening is open, performing a third predetermined period of cleaning on the inner walls of the inner cavity and the inner walls of the outer cavity. This invention effectively improves the uniformity of film deposition and cleaning, increases cleaning speed, and reduces cleaning time. Attached Figure Description

[0018] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0019] Figure 1 This is a schematic diagram of the composition and structure of an embodiment of the PECVD reaction chamber of the present invention.

[0020] Figure 2 for Figure 1 A three-dimensional structural diagram of the inner cavity 1.

[0021] Figure 3 for Figure 1 A partial frontal view of the internal cavity 1 is shown in the schematic diagram.

[0022] Figure 4 for Figure 2 A three-dimensional structural diagram of the first cavity 10.

[0023] Figure 5 for Figure 4 A schematic diagram of the structure in which the first cavity door 10 is in the open state.

[0024] Figure 6 for Figure 4 A schematic diagram of the structure in which the first chamber door 10 is in the closed state.

[0025] Figure 7 This is a schematic diagram illustrating the specific process of an embodiment of the PECVD coating and cleaning method of the present invention. Detailed Implementation

[0026] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a thorough understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] Furthermore, the terms "upper," "lower," "left," "right," "top," "bottom," "horizontal," and "vertical" used in the following description should be understood as the orientations shown in the relevant paragraphs and accompanying drawings. These relative terms are for illustrative purposes only and do not imply that the described apparatus must be manufactured or operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0029] It is understood that although terms such as "first," "second," and "third" may be used herein to describe various components, regions, layers, and / or parts, these components, regions, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers, and / or parts. Therefore, the first components, regions, layers, and / or parts discussed below may be referred to as second components, regions, layers, and / or parts without departing from some embodiments of the present invention.

[0030] See Figures 1 to 3 , Figure 1 This is a schematic diagram of the composition and structure of an embodiment of the PECVD reaction chamber of the present invention. Figure 2 and Figure 3 They are respectively Figure 1 A three-dimensional structural diagram of the inner cavity 1, and a partial frontal structural diagram. (See attached diagram.) Figures 1 to 3 As shown, the PECVD reaction chamber of the present invention includes an inner cavity 1, an outer cavity 20, an RF power supply 22, and a vacuum module 24. The inner cavity 1 is disposed in and communicates with the outer cavity 20. The inner cavity includes an inner cavity door, a heating plate 14, an RF electrode plate 15, a transmission device 16, a PECVD film formation module 17, and a cleaning module 18. The inner cavity door includes a first cavity door 10 and a second cavity door 11 disposed between two inner cavity walls 12 and opposite to each other. Each cavity door 10 and the second cavity door 11 includes multiple door openings 100, multiple door plates 102, and a driving device 13 for driving the multiple door plates 102 to open or close the corresponding door openings 100 (see also [reference]). Figures 4 to 6 ).

[0031] like Figures 1 to 3As shown, multiple radio frequency electrode plates 15 are vertically arranged in parallel within the inner cavity, and the radio frequency electrode plates 15 are connected to the radio frequency power supply 22. Multiple heating plates 14 are vertically arranged in parallel within the inner cavity, spaced apart from the multiple radio frequency electrode plates 15, and the heating plates 14 are grounded. A transmission device 16 is located at the bottom of the inner cavity, used to pass multiple vertically arranged parallel carrier plates 3, each loaded with silicon wafers, through the first cavity door 10 or the second cavity door 11 on both sides of the multiple heating plates 14 into or out of the PECVD reaction chamber. The transmission device 16 can be a sprocket transmission device, which includes a drive shaft and a sprocket or gear mounted on the drive shaft. The drive shaft is driven by a motor to rotate the sprocket or gear, thereby driving the carrier plates 3.

[0032] When the PECVD film deposition module 17 receives the film deposition command, it controls the vacuum module 24 to evacuate the outer cavity 20 and the inner cavity 1, and sends a first trigger signal to the drive device 13 of the inner cavity door to drive the door plate 102 to move to the position corresponding to open the corresponding door opening 100. It is also used to control the film deposition gas DG to enter the inner cavity and turn on the radio frequency power supply 22 when the inner cavity pressure reaches the film deposition pressure, so that the film deposition gas DG is dissociated into plasma by the radio frequency voltage between the radio frequency electrode plate 15 and the heating plate 14, thereby depositing a film layer of a preset thickness on the silicon wafer. It is also used to drive the transmission device 16 to transport the carrier plate 3 carrying the silicon wafer after film deposition out of the PECVD reaction chamber.

[0033] The film-forming gas DG includes SiH4 and H2, and also includes CO2, CH4, NO2, PH3 or B2H6. The film-forming pressure is 0.1-10 mbar, the predetermined thickness is 5-50 nm, and the film layer includes an intrinsic amorphous silicon layer, an N-type amorphous silicon / microcrystalline silicon layer, and a P-type amorphous silicon / microcrystalline silicon layer.

[0034] The cleaning module 18 is used to send a second trigger signal to the drive device 13 of the inner cavity door to drive the door plate 102 to move to the position of closing the corresponding door opening 100 after the PECVD film deposition module 17 has been running for a first predetermined period of time or after receiving a cleaning command. It is also used to control the cleaning gas CG to enter the inner cavity 1 and, after dissociating into plasma, clean the films deposited on the inner walls of the inner cavity 1. Furthermore, during a second predetermined period of cleaning, it sends a third trigger signal to the drive device 13 of the inner cavity door to drive the door plate 102 to move to the position of opening the corresponding door opening 100, thus cleaning the inner walls of the inner cavity 1 and the inner walls of the outer cavity 20 for a third predetermined period of time. The first predetermined period of time is 20-200 hours. The second predetermined period of time is 1000-30000 seconds, and the third predetermined period of time is 100-3000 seconds.

[0035] The cleaning gas CG includes NF3 and Ar, with an NF3 flow rate of 1-100 slm, an Ar flow rate of 0-50 slm, and a cleaning pressure of 0.1-10 mbar. NF3 is dissociated into plasma by the radio frequency voltage between the radio frequency electrode plate 15 and the heating plate 14.

[0036] The PECVD reaction chamber may also include a remote plasma source 26, wherein part or all of the cleaning gas DG is F-containing cleaning plasma provided by the remote plasma source 26.

[0037] See Figures 4 to 6 , Figure 4 for Figure 2 A three-dimensional structural diagram of the first cavity 10. Figure 5 and Figure 6 They are respectively Figure 4 A schematic diagram showing the structure of the first chamber 10 in the open and closed states. (See attached diagram.) Figures 4 to 6 As shown, the first cavity door 10 includes multiple door openings 100, multiple door panels 102, and a drive device 13 for driving the multiple door panels 102 to open or close the corresponding door openings 100. The drive module 13 includes a cylinder 130 and a transmission mechanism 132, which converts the linear motion output by the cylinder 130 into a rotational motion that drives the door panels 102 to rotate.

[0038] See Figure 7 This is a schematic flowchart illustrating a specific embodiment of the PECVD coating and cleaning method of the present invention. The PECVD coating and cleaning method of the present invention is implemented through... Figure 1 The PECVD reaction chamber shown is used. Figure 7 As shown, the PECVD coating and cleaning method S70 of the present invention first performs step S700, in which the PECVD film forming module determines whether a film forming instruction has been received. If so, it continues to step S710; otherwise, it continues to step S700.

[0039] In step S710, multiple carrier plates, which are arranged vertically in parallel and loaded with silicon wafers, are introduced into the inner cavity via a first cavity door or a second cavity door on both sides of multiple heating plates through a transmission device located at the bottom of the inner cavity.

[0040] The PECVD coating and cleaning method S70 continues to step S720, in which the PECVD film formation module controls the vacuum module to evacuate the outer cavity and inner cavity of the PECVD reaction chamber, and sends a first trigger signal to the drive device of the inner cavity door to drive the door plate to move to the position corresponding to open the corresponding door opening.

[0041] The PECVD deposition and cleaning method S70 continues to step S730, where the PECVD film deposition module controls the film deposition gas to enter the inner cavity, and when the inner cavity pressure reaches the film deposition pressure, the radio frequency power supply is turned on, causing the film deposition gas to dissociate into plasma through the radio frequency voltage between the radio frequency electrode plate and the heating plate, thereby depositing a film layer of a predetermined thickness on the silicon wafer. The film deposition gas in step S730 includes SiH4 and H2, and also includes CO2, CH4, NO2, PH3 or B2H6, the film deposition pressure is 0.2-10 mbar, the predetermined thickness is 5-50 nm, and the film layer includes an intrinsic amorphous silicon layer, an N-type amorphous silicon / microcrystalline silicon layer, and a P-type amorphous silicon / microcrystalline silicon layer.

[0042] The PECVD coating and cleaning method S70 continues to step S740, in which the transfer device transfers multiple carrier plates loaded with the silicon wafers after film formation out of the PECVD reaction chamber through the first or second chamber door on both sides of the multiple heating plates.

[0043] The PECVD coating and cleaning method S70 continues to step S750, where the PECVD film formation module determines whether its continuous operation has exceeded a first predetermined time period. If so, a cleaning command is generated and output (step S760); otherwise, it returns to step S700. The first predetermined time period in step S750 is 20-200 hours.

[0044] The PECVD coating and cleaning method S70 continues to step S770, where the cleaning module determines whether a cleaning instruction has been received. If so, it continues to step S780; otherwise, it returns to step S750.

[0045] In step S780, the cleaning module sends a second trigger signal to the drive device of the inner cavity door to drive the door panel to move to the position of closing the corresponding door opening.

[0046] The PECVD coating and cleaning method S70 continues to step S790, where the cleaning module controls the cleaning gas to enter the inner cavity and, after dissociating into plasma, cleans the thin film deposited on each inner wall of the inner cavity. During a second predetermined cleaning period, a third trigger signal is sent to the drive device of the inner cavity door to drive the door panel to move to the position where the corresponding door opening is located, thus performing a third predetermined cleaning period on each inner wall of the inner cavity and each inner wall of the outer cavity. The second and third predetermined cleaning periods in step S790 are 1000-30000 seconds and 100-3000 seconds, respectively.

[0047] The PECVD coating and cleaning method of the present invention can improve the film uniformity from 5-15% in the prior art to 20-30%, and the cleaning speed is also increased from 2-3 nm / s in the prior art to 4-5 nm / s.

[0048] In summary, the PECVD reaction chamber of the present invention includes an outer cavity, an inner cavity, an RF power supply, and a vacuum module. The inner cavity is disposed within and communicates with the outer cavity. The inner cavity includes an inner cavity door, multiple vertically parallel RF electrode plates arranged therein and connected to the RF power supply, multiple vertically parallel heating plates arranged therein and spaced apart from the multiple RF electrode plates and grounded, a transmission device, a PECVD film deposition module, and a cleaning module. The inner cavity door includes a first cavity door and a second cavity door disposed between two inner cavity walls and opposite to each other. Each of the first and second cavity doors includes multiple door openings, multiple door plates, and a driving device for driving the multiple door plates to open or close the corresponding door openings. The transmission device is disposed at the bottom of the inner cavity and is used to pass multiple vertically parallel carrier plates loaded with silicon wafers through the first cavity door or the second cavity door to the inner cavity or to transport them out of the PECVD reaction chamber from both sides of the multiple heating plates. When the PECVD film deposition module receives a film deposition command, it controls the vacuum module to evacuate the outer cavity and the inner cavity and to pump vacuum into the inner cavity. The door drive device sends a first trigger signal to drive the door panel to move to the position corresponding to the opening of the corresponding doorway, and is used to control the film-forming gas to enter the inner cavity and turn on the radio frequency power supply when the pressure in the inner cavity reaches the film-forming pressure, so that the film-forming gas is dissociated into plasma by the radio frequency voltage between the radio frequency electrode plate and the heating plate, thereby depositing a film layer of a preset thickness on the silicon wafer. It is also used to drive the transmission device to transport the carrier plate carrying the silicon wafer after film formation out of the PECVD reaction chamber. The cleaning module is used to send a second trigger signal to the drive device of the inner cavity door to drive the door panel to move to the position to close the corresponding doorway when the PECVD film formation module is running continuously for a first predetermined period of time or after receiving a cleaning command, and is used to control the cleaning gas to enter the inner cavity and clean the film deposited on each inner wall of the inner cavity after dissociation into plasma. When the cleaning continues for a second predetermined period of time, it sends a third trigger signal to the drive device of the inner cavity door to drive the door panel to move to the position to open the corresponding doorway, and cleans each inner wall of the inner cavity and each inner wall of the outer cavity for a third predetermined period of time. This invention can effectively improve the uniformity of coating and cleaning, increase cleaning speed, and reduce cleaning time.

[0049] The prior description of this disclosure is provided to enable any person skilled in the art to make or use it. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not intended to be limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein. The above embodiments are provided to those skilled in the art for implementing or using the invention. Those skilled in the art can make various modifications or changes to the above embodiments without departing from the inventive concept of the invention. Therefore, the scope of protection of the invention is not limited to the above embodiments, but should be the maximum scope conforming to the innovative features mentioned in the claims.

Claims

1. A PECVD reaction chamber, comprising an outer cavity, an inner cavity, a radio frequency power supply, and a vacuum module, wherein the inner cavity is disposed within and communicates with the outer cavity, characterized in that, The inner cavity includes: The inner cavity door includes a first cavity door and a second cavity door disposed between two inner cavity walls and opposite to each other. Each of the first cavity door and the second cavity door includes multiple door openings, multiple door panels, and a driving device for driving the multiple door panels to open or close the corresponding door openings. Multiple vertically parallel radio frequency electrode plates are arranged therein, and the radio frequency electrode plates are connected to the radio frequency power supply; Multiple heating plates are arranged vertically in parallel therein, and the heating plates are spaced apart from multiple radio frequency electrode plates and grounded; A transfer device, which is disposed at the bottom of the inner cavity, is used to transfer multiple vertically parallel carrier plates loaded with silicon wafers through the first cavity door or the second cavity door to the inner cavity or to the PECVD reaction chamber on both sides of the multiple heating plates. The PECVD film deposition module, upon receiving a film deposition command, controls the vacuum module to evacuate the outer and inner cavities, and sends a first trigger signal to the drive device of the inner cavity door to drive the door plate to move to the position corresponding to the opening of the corresponding doorway. It also controls the entry of film deposition gas into the inner cavity and activates the radio frequency power supply when the inner cavity pressure reaches the film deposition pressure, causing the film deposition gas to dissociate into plasma via the radio frequency voltage between the radio frequency electrode plate and the heating plate, thereby depositing a film layer of a preset thickness on the silicon wafer. Furthermore, it drives the transmission device to transport the carrier plate carrying the deposited silicon wafer out of the PECVD reaction chamber. The cleaning module is used to send a second trigger signal to the drive device of the inner cavity door to drive the door plate to move to the position of closing the corresponding door opening after the PECVD film deposition module has been running for a first predetermined period of time or after receiving a cleaning command. It is also used to control the cleaning gas to enter the inner cavity and clean the film deposited on each inner wall of the inner cavity after dissociating into plasma. When the cleaning continues for a second predetermined period of time, it sends a third trigger signal to the drive device of the inner cavity door to drive the door plate to move to the position of opening the corresponding door opening, and cleans each inner wall of the inner cavity and each inner wall of the outer cavity for a third predetermined period of time.

2. The PECVD reaction chamber according to claim 1, characterized in that, The first predetermined time period is 20-200 hours, the second predetermined time period is 1000-30000 seconds, and the third predetermined time period is 100-3000 seconds.

3. The PECVD reaction chamber according to claim 1, characterized in that, The film-forming gas includes SiH4 and H2, and also includes CO2, CH4, NO2, PH3 or B2H6. The film-forming pressure is 0.1-10 mbar, the predetermined thickness is 5-50 nm, and the film layer includes an intrinsic amorphous silicon layer, an N-type amorphous silicon / microcrystalline silicon layer, and a P-type amorphous silicon / microcrystalline silicon layer.

4. The PECVD reaction chamber according to claim 1, characterized in that, The cleaning gas includes NF3 and Ar, with an NF3 flow rate of 1-100 slm, an Ar flow rate of 0-50 slm, and a cleaning pressure of 0.1-10 mbar. NF3 is dissociated into plasma by the radio frequency voltage between the radio frequency electrode plate and the heating plate.

5. The PECVD reaction chamber according to claim 1 or 4, characterized in that, The PECVD reaction chamber also includes a remote plasma source, and the cleaning gas is partly or entirely F-containing cleaning plasma provided by the remote plasma source.

6. A PECVD film formation and cleaning method, characterized in that, It is carried out through the PECVD reaction chamber as described in claims 1 to 5, and includes the following steps: Step 1: The PECVD film deposition module determines whether a film deposition command has been received. If so, multiple vertically parallel carriers loaded with silicon wafers are transferred into the inner cavity via the first or second cavity door through the transfer device located at the bottom of the inner cavity. Step 2: The PECVD film formation module controls the vacuum module to evacuate the outer and inner cavities of the PECVD reaction chamber, and sends a first trigger signal to the drive device of the inner cavity door to drive the door plate to move to the position where the corresponding door opening is located. Step 3: The PECVD film deposition module controls the film deposition gas to enter the inner cavity and turns on the radio frequency power supply when the pressure in the inner cavity reaches the film deposition pressure. The film deposition gas is then dissociated into plasma by the radio frequency voltage between the radio frequency electrode plate and the heating plate, thereby depositing a film layer of a preset thickness on the silicon wafer. Step 4: The transmission device transports multiple carrier plates loaded with silicon wafers after film formation out of the PECVD reaction chamber through the first or second chamber door on both sides of the multiple heating plates. Step 5: The PECVD film formation module determines whether its continuous operation has exceeded the first predetermined time period. If so, it generates and outputs a cleaning command; otherwise, it returns to step 1. Step six: The cleaning module determines whether a cleaning command has been received. If so, it sends a second trigger signal to the drive device of the inner door to drive the door panel to move to the position where the corresponding door opening is closed; and Step 7: The cleaning module controls the cleaning gas to enter the inner cavity and cleans the thin film deposited on each inner wall of the inner cavity after dissociating into plasma. During the second predetermined cleaning period, a third trigger signal is sent to the drive device of the inner cavity door to drive the door panel to move to the position of opening the corresponding door opening, and the inner walls of the inner cavity and the inner walls of the outer cavity are cleaned for a third predetermined period.

7. The PECVD coating and cleaning method according to claim 6, characterized in that, The first predetermined time period in step five is 20-200 hours, and the second and third predetermined time periods in step seven are 1000-30000 seconds and 100-3000 seconds, respectively.

8. The PECVD coating and cleaning method according to claim 6, characterized in that, The film-forming gas in step three includes SiH4 and H2, and also includes CO2, CH4, NO2, PH3 or B2H6. The film-forming pressure is 0.2-10 mbar, the predetermined thickness is 5-50 nm, and the film layer includes an intrinsic amorphous silicon layer, an N-type amorphous silicon / microcrystalline silicon layer, and a P-type amorphous silicon / microcrystalline silicon layer.

9. The PECVD coating and cleaning method according to claim 6, characterized in that, The cleaning gas in step seven includes NF3 and Ar. The flow rate of NF3 is 1-100 slm, the flow rate of Ar is 0-50 slm, and the cleaning pressure is 0.1-10 mbar. NF3 is dissociated into plasma by the radio frequency voltage between the radio frequency electrode plate and the heating plate.

10. The PECVD coating and cleaning method according to claim 1 or 9, characterized in that, The cleaning gas in step seven is partly or entirely F-containing cleaning plasma provided by a remote plasma source.

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