HWCVD coating apparatus and coating process

Abstract

The application discloses a kind of HWCVD coating equipment and coating process, HWCVD coating equipment includes coating chamber, carrier plate and drive module, multiple rows of wire lines are arranged in coating cavity along the first direction interval, process gas is introduced into coating cavity parallel to the extension direction of wire line, carrier plate is used to carry the substrate to be plated, drive module is used to drive carrier plate to move along the second direction, the extension direction of the wire line and the second direction are mutually a angle, coating process is executed using HWCVD coating equipment.In the coating process, the substrate to be plated moves synchronously with carrier plate, a certain plating position on the substrate to be plated can be moved to different thermal radiation areas around hot wire, the deposition of active particles in different areas to the substrate to be plated is homogenized in the process of carrier plate movement, the active particles formed by catalytic cracking around hot wire are disturbed, the distribution of active particles in different radiation areas is more balanced, and active particles can be uniformly deposited on the surface of the substrate to be plated, to improve the uniformity of coating.

Description

Technical Field

[0001] This invention relates to the field of solar cell fabrication technology, and in particular to an HWCVD coating equipment and coating process. Background Technology

[0002] Hot-wire chemical vapor deposition (HWCVD) utilizes process gases to undergo catalytic decomposition reactions on a hot filament, resulting in deposition and polymerization on the substrate surface to form a thin film. It can be applied to the deposition of amorphous silicon layers and doped microcrystalline silicon layers in high-efficiency heterojunction (HJT) solar cells. The arrangement of the hot filament and the delivery method of the process gases directly affect the uniformity of the coating. Related technologies improve the uniformity of the film by changing the spacing between the hot filaments or silicon wafers and the airflow direction, but this increases the complexity of the equipment and the cost of coating, resulting in low production efficiency. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes an HWCVD coating apparatus that can improve coating uniformity.

[0004] The present invention also proposes an HWCVD coating process performed using the above-mentioned HWCVD coating equipment.

[0005] An HWCVD coating apparatus according to a first aspect of the present invention includes:

[0006] The coating chamber has a coating cavity inside, and multiple rows of filaments are arranged along a first direction inside the coating cavity. The coating chamber also has an air outlet for introducing process gas into the coating cavity. The air outlet is located between adjacent filaments in the first direction so that the airflow flows parallel to the extension direction of the filaments.

[0007] The carrier plate is used to support the substrate to be plated.

[0008] A drive module is connected to the carrier plate and is used to drive the carrier plate to move along a second direction, which is parallel to the plane containing the first direction and the extension direction of the filament, and forms an angle α with the extension direction of the filament, where 0° < α < 180°.

[0009] The HWCVD coating apparatus according to embodiments of the present invention has at least the following beneficial effects:

[0010] During the coating process, the substrate to be coated moves synchronously with the carrier plate. A certain position on the substrate to be coated can move to different thermal radiation areas around the hot wire. The deposition of active particles in different areas onto the substrate is homogenized during the movement of the carrier plate, achieving uniform coating. The active particles formed by catalytic cracking around the hot wire are disturbed, which can change the original distribution pattern of the active particles, making the distribution of active particles in different radiation areas around the hot wire more balanced. The active particles can be uniformly deposited on the surface of the substrate to be coated, improving the uniformity of the coating.

[0011] According to some embodiments of the present invention, the driving module drives the carrier plate to reciprocate along the second direction, wherein the first direction is parallel to the second direction;

[0012] Alternatively, the drive module drives the carrier plate to oscillate parallel to the first direction and the extension direction of the filament.

[0013] According to some embodiments of the present invention, the second direction is parallel to the first direction, the reciprocating movement distance of the carrier plate along the second direction is defined as L1, the spacing between adjacent threads in the first direction is L2, L1 = 0.5k * L2, where k is a positive integer.

[0014] According to some embodiments of the present invention, the coating chamber further has an exhaust port, which is located on opposite sides of the carrier plate with respect to the exhaust port. The carrier plate is closed between its two ends in the first direction and the inner wall of the coating chamber, and there is a gap between the two ends of the carrier plate in the filament extension direction and the inner wall of the coating chamber.

[0015] According to a second aspect embodiment of the present invention, the HWCVD coating process is performed using the HWCVD coating equipment of the first aspect embodiment, and includes a first deposition step:

[0016] The substrate to be coated is supported on the carrier plate and placed in the coating cavity. The driving module drives the carrier plate to move along the second direction.

[0017] In the first instant, the operation of the filament is controlled, and process gas is introduced into the coating cavity through the air outlet;

[0018] The filament process ends and the flow of process gas into the coating cavity is stopped, and then the movement of the carrier plate is stopped.

[0019] According to some embodiments of the present invention, the first deposition step includes:

[0020] During the first time period, the drive module is controlled to drive the carrier plate to move a distance L1 along the first direction, and the spacing between adjacent silk lines in the first direction is L2, where L1 = k * 0.5L2, and k is a positive integer.

[0021] According to some embodiments of the present invention, the first deposition step further includes:

[0022] Before the filament is started to work, a non-coating gas is introduced into the coating chamber. After the filament enters the preset working state, a process gas is introduced into the coating chamber through the gas outlet. After the first time, the process gas is stopped from being introduced into the coating chamber, and a non-coating gas is introduced into the coating chamber. Then the filament is controlled to stop working.

[0023] Alternatively, after the filament starts working and enters a preset working state, process gas is introduced into the coating cavity through the air outlet; after the first time, the introduction of process gas into the coating cavity is stopped, and then the filament is controlled to stop working.

[0024] According to some embodiments of the present invention, the first deposition step further includes:

[0025] Intermittent deposition: After the first time, the deposition is stopped for a second time, and the filament is controlled to work again during the first time, and process gas is introduced into the coating chamber through the gas outlet;

[0026] The intermittent deposition step is repeated n times, where n≥1.

[0027] According to some embodiments of the present invention, the step of stopping deposition includes:

[0028] Control the silk thread to stop working, and after the second time, control the silk thread to start working again;

[0029] Alternatively, the substrate to be plated can be isolated from the wire, and after the second time, the substrate to be plated can be controlled to return to the working environment of the wire.

[0030] According to some embodiments of the present invention, the HWCVD coating process includes:

[0031] Control the exposure of the P-side of the substrate to be deposited, and perform the first deposition step to form an intrinsic amorphous silicon thin film on the P-side of the substrate to be deposited.

[0032] The N-side of the substrate to be deposited is exposed, and the first deposition step is performed to form an intrinsic amorphous silicon thin film on the N-side of the substrate to be deposited.

[0033] According to some embodiments of the present invention, the HWCVD coating process further includes a second deposition step:

[0034] After the first deposition step is completed, a P-type microcrystalline silicon film is deposited on the intrinsic amorphous silicon film on the P-side of the substrate to be deposited, and an N-type microcrystalline silicon film is deposited on the intrinsic amorphous silicon film on the N-side of the substrate to be deposited.

[0035] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0037] Figure 1 This is a side view of an embodiment of the HWCVD coating equipment of the present invention;

[0038] Figure 2 This is a top view of an embodiment of the HWCVD coating equipment of the present invention;

[0039] Figure 3 A schematic diagram of one embodiment of a solar cell;

[0040] Figure 4 This is a flowchart of the first deposition step in the HWCVD coating process of the present invention;

[0041] Figure 5 This is a flowchart of one embodiment of the HWCVD coating process of the present invention;

[0042] Figure 6 This is a flowchart of another embodiment of the HWCVD coating process of the present invention;

[0043] Figure 7 This is a schematic diagram of the first and second deposition steps in the HWCVD coating process of the present invention.

[0044] Figure label:

[0045] Coating chamber 100, coating cavity 110, air outlet 120, air extraction port 130; carrier plate 200; drive module 300; wire thread 400, hot wire 410. Detailed Implementation

[0046] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0047] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0048] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0049] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0050] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0051] Reference Figure 1 and Figure 2The present invention provides an HWCVD coating equipment (hereinafter referred to as coating equipment), including a coating chamber 100, a carrier plate 200 and a drive module 300. The coating chamber 100 has a coating cavity 110 inside, which can provide a stable coating atmosphere for the substrate to be coated. The coating cavity 110 is provided with multiple rows of filaments 400 arranged at intervals along a first direction. After being heated, the filaments 400 can decompose the process gas molecules through high temperature, and at the same time play a catalytic role in the process gas reaction, accelerating the deposition rate of molecules. The coating equipment has high coating efficiency. The coating chamber 100 also has an outlet 120 for introducing process gas into the coating chamber 110. The outlet 120 is located between adjacent filaments 400 in the first direction. The process gas discharged from the outlet 120 flows along the extension direction of the filaments 400. The process gas is unobstructed in the flow path and can diffuse to different areas in the extension direction of the filaments 400. Furthermore, the film will not show streaks due to the discontinuity within the filaments 400, thus improving the uniformity of the coating.

[0052] The carrier plate 200 is located within the coating chamber 110 and serves to support the substrate to be coated. Alternatively, the carrier plate 200 carrying the substrate can enter and exit the coating chamber 110 through the inlet and outlet of the coating chamber 100. It is understood that valves are installed at the inlet and outlet of the coating chamber 100 to allow the carrier plate 200 to enter and exit the coating chamber 110, and to seal the coating chamber 110, providing a sealed and stable coating environment for the substrate. Process gases (such as hydrogen, silane, etc.) are introduced into the coating chamber 110 and undergo catalytic decomposition on the heated filament 400, depositing onto the surface of the substrate to form a thin film. After the hot filament 410 is heated, it radiates heat to the surrounding environment. The process gases in different areas around the hot filament 410 receive varying degrees of heat radiation, resulting in different degrees of catalytic decomposition in different areas. This leads to uneven distribution of the active particles generated after decomposition, causing streaks to appear on the thin film deposited on the substrate.

[0053] Based on the above, in this invention, the driving module 300 drives the carrier plate 200 to move along the second direction. The second direction is parallel to the plane containing the first direction and the extension direction of the filament 400, and forms an angle α with the extension direction of the filament 400, where 0° < α < 180°. It can be seen that the moving direction of the carrier plate 200 is not parallel to the extension direction of the hot filament 410. During the coating process, when the carrier plate 200 is driven by the driving module 300 to move along the second direction, the substrate to be coated moves synchronously with the carrier plate 200. A certain position on the substrate to be coated can move to different thermal radiation areas around the hot filament 410. The deposition of active particles in different areas onto the substrate to be coated is homogenized during the movement of the carrier plate 200, achieving uniform coating. In addition, through the above-mentioned dynamic coating, the active particles formed by catalytic cracking around the hot filament 410 are disturbed, which can change the original distribution pattern of the active particles, making the distribution of active particles in different radiation areas around the hot filament 410 more balanced. The active particles can be uniformly deposited on the surface of the substrate to be coated, improving the coating uniformity.

[0054] Reference Figure 3 , Figure 3 A schematic diagram of a solar cell in one embodiment is provided. The substrate to be coated can be a crystalline silicon wafer. Intrinsic amorphous silicon thin films are coated on both sides of the crystalline silicon wafer. An N-type microcrystalline silicon thin film or a P-type microcrystalline silicon thin film is coated on the side of the intrinsic amorphous silicon thin film facing away from the silicon wafer. Therefore, the coating process of the solar cell needs to include the process of forming an intrinsic amorphous silicon thin film on the surface of the silicon wafer and forming a microcrystalline silicon thin film on the surface of the intrinsic amorphous silicon thin film. Traditional coating processes require changes to the distance between the hot wire 410 and the silicon wafer, as well as the direction of the process gas flow, at the switching point between amorphous silicon thin film and microcrystalline silicon thin film deposition. This increases the complexity of the coating equipment and production costs. The coating equipment of this invention can be applied to both amorphous silicon thin film deposition and microcrystalline silicon thin film deposition. Furthermore, this invention employs a dynamic coating method. As the substrate to be coated moves continuously with the carrier plate 200, active particles formed by the cracking and catalysis of different radiation regions of the hot wire 410 can be deposited on the surface of the substrate. This eliminates the need to change the initial settings of the hot wire 410, the silicon wafer, and the gas flow, simplifying the coating equipment and improving coating uniformity.

[0055] The carrier plate 200 can be moved by translation or oscillation. For example, the drive module 300 drives the carrier plate 200 to reciprocate along the second direction, or the drive module 300 drives the carrier plate 200 to oscillate parallel to the first direction and the extension direction of the filament 400. The plane containing the extension direction of the filament 400 and the first direction is defined as the moving plane. Driving the carrier plate 200 to translate parallel to the moving plane, or to oscillate parallel to the moving plane, can both achieve the movement of the carrier plate 200 along the second direction, causing the substrate to be plated to change position relative to the hot wire 410 in the second direction, allowing active particles in different thermal radiation areas to deposit onto the substrate. In one embodiment, the moving plane is parallel to the horizontal plane, the filament 400 is located above the carrier plate 200, the substrate to be plated is supported on the upper surface of the carrier plate 200, and the heat released by the hot wire 410 can also preheat the substrate to be plated.

[0056] The drive module 300 includes a drive element that drives the carrier plate 200 to move. For example, the drive module 300 may be configured as a motor capable of outputting rotational power, a motor capable of conveying linear motion, a motor and a lead screw assembly, or a motor and a guide rail slider assembly. Alternatively, the drive module 300 may include a motor and a conveyor roller. The conveyor roller is connected to the motor and is driven to rotate. The carrier plate 200 is placed on the surface of the conveyor roller and moves with the rotation of the conveyor roller. The axial direction of the conveyor roller is parallel to the extension direction of the lead screw 400, so that the direction of movement of the carrier plate 200 is parallel to a first direction.

[0057] Each row of wires 400 includes one or more hot wires 410, the two ends of which are fixed inside the coating chamber 100. In one embodiment, such as Figure 2 Each row of wires 400 includes multiple hot wires 410, which are arranged along the extension direction of the wires 400. Both ends of each hot wire 410 are fixed inside the coating chamber 100. Dividing the wires 400 into multiple hot wires 410 can reduce the amount of sag caused by continuous high-temperature heating of the suspended part of the hot wires 410, so that the distance between different positions of the wires 400 and the substrate to be coated remains consistent, thereby improving the coating uniformity.

[0058] In one embodiment, the second direction is parallel to the first direction, that is, the second direction is perpendicular to the extension direction of the filament 400. The driving module 300 drives the carrier plate 200 to reciprocate along the second direction. The reciprocating distance of the carrier plate 200 along the second direction is defined as L1, and the spacing between adjacent filaments 400 in the first direction is defined as L2. L1 and L2 satisfy: L1 = 0.5k * L2, where k is a positive integer. In each coating cycle, the distance that the carrier plate 200 carries the substrate to be coated moves is half or an integer multiple of the spacing between the filaments 400. In this way, the carrier plate 200 has a large sweeping area when it moves, and the active particles in different thermal radiation areas between the filaments 400 can be deposited on a certain area of ​​the substrate to be coated. This can make up for the coating gaps caused by the distance between adjacent filaments 400 and improve the coating uniformity. In addition, each row of wires 400 will radiate heat into the gap between adjacent wires 400. When the spacing of the wires 400 changes, the coating leakage area between adjacent wires 400 changes and affects the coating uniformity. However, by moving the carrier plate 200 along the second direction, the substrate to be coated can pass through adjacent wires 400 in each coating cycle, and the coating uniformity is not affected by the change in the spacing of the wires 400.

[0059] Understandably, a coating cycle refers to the time required to deposit a thin film on the surface of a substrate. Taking the deposition of an amorphous silicon thin film on the surface of a substrate as an example, if the total thickness of the amorphous silicon thin film is m times the thickness of a single layer of coating, then the coating process needs to be repeated m times to deposit the required thickness of the amorphous silicon thin film. Therefore, the coating process of the amorphous silicon thin film requires m coating cycles, and the distance that the carrier plate 200 moves in each coating cycle is L1.

[0060] like Figure 1 and Figure 2 ( Figure 2 As shown in the curve (used to represent the airflow path), the coating chamber 100 also has an exhaust port 130, which is located on opposite sides of the carrier plate 200, along with the exhaust port 120. The carrier plate 200 has gaps between its two ends in the extending direction of the filament 400 and the inner wall of the coating chamber 100, while the two ends in the first direction are closed to the inner wall of the coating chamber 100. The gap between the carrier plate 200 and the coating chamber 100 serves to guide the flow of the process gas. When the exhaust device extracts gas from the coating chamber 100 through the exhaust port 130, since there is no airflow channel at the end of the carrier plate 200 in the first direction, the airflow can only flow through the gap between the two ends of the carrier plate 200 in the extending direction and the inner wall of the coating chamber 100. This limits the flow direction of the process gas between the carrier plate 200 and the filament 400 to the extending direction of the filament 400, thereby preventing the formation of stripes on the surface of the substrate to be coated.

[0061] It should be noted that the opposite sides of the carrier plate 200 refer to the sides of the carrier plate 200 facing or away from the wire mesh 400. The substrate to be plated is placed on the side of the carrier plate 200 facing the wire mesh 400, and the air outlet 120 is located on the side of the carrier plate 200 facing the wire mesh 400. The process gas discharged from the air outlet 120 flows along the extension direction of the wire mesh 400 under the aforementioned guiding effect, achieving uniform film deposition. Alternatively, the air outlet 120 can be located on the side of the wire mesh 400 away from the carrier plate 200, i.e., above the carrier plate 200, or the air outlet 120 can be located between adjacent wire meshes 400.

[0062] In one embodiment, the coating apparatus includes a plurality of coating chambers 100 arranged sequentially. The coating cavities 110 of adjacent coating chambers 100 are connected or isolated by valves. When the valves are open, the substrate to be coated can enter and exit the adjacent coating chamber 100 along with the carrier plate 200. When the valves are closed, the substrate to be coated is enclosed within the coating cavity 110. For example, the coating apparatus includes four coating chambers 100. The substrate to be coated undergoes P-side amorphous silicon thin film deposition, N-side amorphous silicon thin film deposition, N-side microcrystalline silicon thin film deposition, and P-side microcrystalline silicon thin film deposition sequentially in the four coating chambers 100. Specifically, the four coating chambers 100 are arranged sequentially according to the coating order, and are defined as coating chamber a, coating chamber b, coating chamber c, and coating chamber d. The substrate to be coated enters coating chamber a along with the carrier plate 200. The P-side of the substrate is exposed, and an amorphous silicon thin film is deposited on the P-side in coating chamber a. The carrier plate 200 rotates the substrate and moves it into coating chamber b, where the N-side is exposed and an amorphous silicon thin film is deposited. The carrier plate 200 then moves the substrate into coating chamber c, where an N-side microcrystalline silicon thin film is deposited. Finally, the carrier plate 200 rotates the substrate and moves it into coating chamber d, where a P-side microcrystalline silicon thin film is deposited. By coordinating the different coating chambers 100 and rotating and transporting the substrate by the carrier plate 200, fully automated coating of the substrate can be achieved, which helps improve coating efficiency.

[0063] Alternatively, the carrier plate 200 is rotatably connected to the coating chamber 100, and the drive module 300 can drive the carrier plate 200 to flip so that the P-side or N-side of the substrate to be coated faces the wire 400, enabling the same coating chamber 100 to deposit thin films on different surfaces of the substrate. For example, firstly, the P-side of the substrate to be coated is exposed and faces the wire 400; process gas is introduced, and an amorphous silicon thin film is deposited on the P-side; protective gas is purged from the coating chamber 110, the carrier plate 200 is flipped to expose the N-side and face the wire 400; process gas is introduced, and an amorphous silicon thin film is deposited on the N-side; protective gas is purged from the coating chamber 110, process gas is introduced, and a microcrystalline silicon thin film is deposited on the N-side; protective gas is purged from the coating chamber 110, the carrier plate 200 is flipped to expose the P-side and face the wire 400; process gas is introduced, and an amorphous silicon thin film is deposited on the P-side.

[0064] This invention also provides an HWCVD coating process (hereinafter referred to as the coating process), which is performed using the above-mentioned coating equipment. The coating process includes a first deposition step, as described above. Figure 4 The first deposition step includes the following process: the substrate to be deposited is supported on the carrier plate 200, and the substrate to be deposited follows the carrier plate 200 into the coating chamber 110 or is directly placed into the coating chamber 110. The drive module 300 drives the carrier plate 200 to move continuously along the second direction. Subsequently, in the first time period, the filament 400 is controlled to work, so that the filament 400 is in a high temperature state, and process gas is introduced into the coating chamber 110 through the gas outlet 120. The flow of process gas is along the extension direction of the filament 400, and the second direction is not parallel to the extension direction of the filament 400. The process gas is continuously input into the coating chamber 110 in the first time period and undergoes catalytic decomposition on the high temperature filament 400 to form active particles. The active particles are deposited onto the substrate to be deposited to form a thin film. After the thin film is formed, the filament 400 stops working and stops introducing process gas into the coating chamber 110. The deposition of active particles onto the substrate to be deposited ends. Then, the drive module 300 is controlled to stop driving the carrier plate 200 to move. In this invention, during the coating process, the carrier plate 200 continuously moves the substrate to be coated. A certain position on the substrate to be coated can move to different thermal radiation areas around the hot wire 410. The deposition of active particles in different areas onto the substrate is homogenized during the movement of the carrier plate 200. Furthermore, the active particles formed by catalytic decomposition around the hot wire 410 are disturbed, which can change the original distribution pattern of the active particles, making the distribution of active particles in different radiation areas around the hot wire 410 more balanced. The active particles can be uniformly deposited on the surface of the substrate to be coated, improving the coating uniformity.

[0065] Furthermore, within the first time interval, the control drive module 300 drives the carrier plate 200 to move a distance L1 along the first direction, and the spacing between adjacent silk lines 400 in the first direction is L2, where L1 = k * L2, and k is a positive integer. The first time is one coating cycle, which is the time required for the substrate to deposit a single-layer thin film. In each coating cycle, the distance that the carrier plate 200 carries the substrate to be coated moves is an integer multiple of the spacing between the filaments 400. Active particles in different heat radiation areas between the filaments 400 can be deposited into a certain area of ​​the substrate to be coated, which can make up for the coating gaps caused by the distance between adjacent filaments 400, resulting in high coating uniformity. Each row of filaments 400 will radiate heat into the gaps between adjacent filaments 400. When the spacing of the filaments 400 changes, the coating gaps between adjacent filaments 400 change and affect the coating uniformity. However, by moving the carrier plate 200 along the second direction, the substrate to be coated can pass through adjacent filaments 400 in each coating cycle, and the coating uniformity is not affected by the change in the spacing of the filaments 400.

[0066] Since the hot filament 410 begins the catalytic reaction before reaching the preset working state, to prevent the hot filament 410 from catalyzing before coating and producing low-quality silicon, thus improving the coating quality, this invention incorporates anti-catalysis measures in the first deposition step. Specifically, refer to... Figure 5 Before the wire rod 400 starts working, a non-deposition gas is introduced into the coating chamber 110. This non-deposition gas will not react within the coating chamber 110. The non-deposition gas can be an inert gas, such as N2. After the wire rod 400 enters the preset working state, a process gas is introduced into the coating chamber 110 through the outlet 120 and continued for a first time to complete the deposition of a single-layer thin film onto the substrate. After the first time, the introduction of the process gas into the coating chamber 110 is stopped, and the introduction of the non-deposition gas is switched to the coating chamber 110. Finally, the wire rod 400 is controlled to stop working. When the wire rod 400 is not in the preset working state, and after coating is completed, no process gas is introduced into the coating chamber 110. The process gas will not produce low-quality silicon due to the catalysis of the wire rod 400.

[0067] It should be noted that the preset working state of the wire 400 refers to the wire 400 rising from standby current to rated operating current and continuously radiating heat at the rated operating current. During the process of the wire 400 entering the preset working state and before switching to process gas introduction, the heat released by the wire 400 can preheat the carrier plate 200 and perform surface treatment on the substrate to be coated, thereby simplifying the coating process and the overall structure of the coating equipment. In other embodiments, the coating equipment is provided with a preheating chamber, and the carrier plate 200 is preheated in the preheating chamber before entering the coating chamber 110.

[0068] In another embodiment, reference is made to Figure 6 The anti-catalytic setting for the first deposition step is as follows: Before the wire rod 400 starts working, the deposition chamber 110 is kept in a vacuum state. After the wire rod 400 starts working and enters the preset working state, process gas is introduced into the deposition chamber 110 through the gas outlet 120. This process lasts for a first time, during which the process gas completes the deposition onto the substrate. After the first time, the introduction of process gas into the deposition chamber 110 is stopped, and the deposition chamber 110 is set to a vacuum state. Then, the wire rod 400 is controlled to stop working. Similarly, when the wire rod 400 is not in the preset working state and after the deposition is completed, no process gas is introduced into the deposition chamber 110. The process gas will not produce low-quality silicon due to the catalysis of the wire rod 400.

[0069] It should be noted that the discharge of process gas into the coating chamber 110 and the discharge of non-coating gas into the coating chamber 110 can both be achieved through the outlet 120. For example, multiple inlet pipes are connected to the outlet 120, and the connection between different inlet pipes and the outlet 120 is controlled by valves. Process gas or non-coating gas is introduced into different inlet pipes. By controlling the connection or isolation between the corresponding inlet pipe and the inlet through valves, the switching between process gas and non-coating gas introduced into the coating chamber 110 can be achieved.

[0070] Furthermore, the first deposition step of this invention employs an intermittent deposition method to avoid the high temperature of the hot filament 410 affecting the temperature of the substrate to be deposited, which could lead to reduced coating uniformity or a decrease in deposition rate. Specifically, refer to... Figure 5 and Figure 6 The first deposition step includes an intermittent deposition step, which specifically involves: after a first time period of thin film deposition, deposition on the substrate is stopped for a second time period. After the second time period, the filament 400 is controlled to operate again during the first time period, and process gas is introduced into the coating chamber 110 through the gas outlet 120 to perform thin film deposition. During the second time period when deposition is stopped, the substrate is no longer affected by the high temperature of the hot filament 410. Through intermittent deposition, the temperature of the substrate is maintained within a preset range, avoiding a decrease in deposition rate and coating uniformity caused by increased elastic collisions of active particles due to excessively high substrate temperature.

[0071] Furthermore, for cases with large film thicknesses, an intermittent deposition method can be used to avoid continuously turning on the hot wire 410. This prevents over-catalysis of the hot wire 410 and reduces the impact of the high temperature of the hot wire 410 on the substrate. The first deposition step includes n cycles of intermittent deposition, where n ≥ 1. Intermittent deposition steps are included between adjacent film deposition steps. Taking the deposition of amorphous silicon thin films as an example, the total thickness of the amorphous silicon thin film is n+1 times the thickness of a single-layer film. Each single-layer film undergoes one intermittent deposition step, and the amorphous silicon thin film deposition is completed after n+1 film depositions. It can be understood that the total time of the first deposition step is the sum of n+1 times the first time and n times the second time.

[0072] Deposition can be stopped by controlling the wire guide 400 to cease operation, thus eliminating heat generation and preventing the substrate from being affected by its high temperature. After a second period of time following the wire guide 400's shutdown, the wire guide 400 is restarted for another thin film deposition. Alternatively, deposition can be stopped by isolating the substrate from the wire guide 400, ensuring it is no longer in the high-temperature environment surrounding the wire guide 400 and is no longer affected by its high temperature. After a second period of isolation, the substrate is brought back into the working environment of the wire guide 400 for another thin film deposition. It is understood that isolating the substrate from the wire guide 400 can be achieved by installing a baffle within the coating chamber 110, separating the wire guide 400 from the substrate within different chambers, thus keeping the substrate away from the high-heat environment of the wire guide 400. After the second period, the baffle is removed, and the substrate is returned to the high-temperature environment of the wire guide 400.

[0073] Taking one of the anti-catalytic methods and one of the intermittent deposition methods as examples, the specific process of the first deposition step is as follows: When the coating chamber 110 is in a vacuum state, a non-coating gas is introduced into the coating chamber 110. After the wire 400 enters the preset working state, the process gas is switched to be introduced into the coating chamber 110. This process lasts for a first time, completing a single film deposition on the substrate to be coated. After the first time, the process switches again to introduce a non-coating gas into the coating chamber 110, and at the same time, the wire 400 is controlled to stop working and intermittent deposition is performed. This process lasts for a second time. After the second time, the wire 400 is controlled to enter the preset working state, and the process gas is switched to be introduced into the coating chamber 110. This process lasts for a first time, completing a second single film deposition on the substrate to be coated... After completing n+1 depositions on the substrate to be coated, the first deposition step is completed. It should be noted that during the first deposition step, the drive module 300 always keeps the drive carrier 200 moving. Through the anti-catalytic design, intermittent deposition, and dynamic coating method in this invention, the coating uniformity, deposition efficiency, and deposition quality can be maximized.

[0074] The first deposition step described above can be used for amorphous silicon thin film deposition or microcrystalline silicon thin film deposition in solar cells. Specifically, the coating process includes the following steps: controlling the P-side of the substrate to be coated to be exposed, and performing the first deposition step to complete the deposition of an intrinsic amorphous silicon thin film on the P-side of the substrate; and controlling the N-side of the substrate to be coated to be exposed, and performing the first deposition step to complete the deposition of an intrinsic amorphous silicon thin film on the N-side of the substrate. Thus, amorphous silicon thin film deposition is achieved on the opposite surfaces of the substrate. It should be noted that the order of intrinsic amorphous silicon thin film deposition on the P-side and N-side is not restricted.

[0075] Furthermore, refer to Figure 7The coating process also includes a second deposition step, which is set after the first deposition step. This second deposition step is used to deposit a P-type microcrystalline silicon film onto the intrinsic amorphous silicon film on the P-side of the substrate, and an N-type microcrystalline silicon film onto the intrinsic amorphous silicon film on the N-side of the substrate. It should be noted that the second deposition step can also employ the intermittent deposition, dynamic coating, and anti-catalytic deposition methods used in the first deposition step.

[0076] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A HWCVD coating apparatus, characterized in that include: The coating chamber has a coating cavity inside, and multiple rows of filaments are arranged along a first direction inside the coating cavity. The coating chamber also has an air outlet for introducing process gas into the coating cavity. The air outlet is located between adjacent filaments in the first direction so that the airflow flows parallel to the extension direction of the filaments. The carrier plate is used to support the substrate to be plated. A drive module is connected to the carrier plate and is used to drive the carrier plate to move along a second direction, which is parallel to the plane containing the first direction and the extension direction of the filament, and forms an angle α with the extension direction of the filament, where 0° < α < 180°. The coating chamber also has an air extraction port, which is located on opposite sides of the carrier plate. The two ends of the carrier plate in the first direction are closed to the inner wall of the coating chamber, and the two ends of the carrier plate in the filament extension direction have a gap with the inner wall of the coating chamber. Each row of wires includes multiple hot wires, which are arranged along the extension direction of the row of wires, and both ends of each hot wire are fixed inside the coating chamber. The second direction is parallel to the first direction, that is, the second direction is perpendicular to the extension direction of the silk thread.

2. The HWCVD coating equipment according to claim 1, characterized in that, The driving module drives the carrier plate to reciprocate and translate along the second direction, wherein the first direction is parallel to the second direction; Alternatively, the drive module drives the carrier plate to swing parallel to the first direction and the extension direction of the filament.

3. The HWCVD coating equipment according to claim 1, characterized in that, The second direction is parallel to the first direction. The driving module drives the carrier plate to translate along the second direction. The reciprocating movement distance of the carrier plate along the second direction is defined as L1, and the spacing between adjacent silk lines in the first direction is L2. L1 = 0.5k * L2, where k is a positive integer.

4. HWCVD coating process, characterized in that, Performed using the HWCVD coating equipment according to any one of claims 1 to 3, including a first deposition step: The substrate to be coated is supported on the carrier plate and placed in the coating cavity. The driving module drives the carrier plate to move along the second direction. In the first instant, the operation of the filament is controlled, and process gas is introduced into the coating cavity through the air outlet; The filament process ends and the flow of process gas into the coating cavity is stopped, and then the movement of the carrier plate is stopped.

5. The HWCVD coating process according to claim 4, characterized in that, The first deposition step includes: During the first time period, the driving module is controlled to drive the carrier plate to move a distance L1 along the first direction, and the spacing between adjacent silk lines in the first direction is L2, where L1 = 0.5k * L2, and k is a positive integer.

6. The HWCVD coating process according to claim 4, characterized in that, The first deposition step further includes: Before the filament is started to work, a non-coating gas is introduced into the coating chamber. After the filament enters the preset working state, a process gas is introduced into the coating chamber through the gas outlet. After the first time, the process gas is stopped from being introduced into the coating chamber, and a non-coating gas is introduced into the coating chamber. Then the filament is controlled to stop working. Alternatively, after the filament starts working and enters a preset working state, process gas is introduced into the coating cavity through the air outlet; after the first time, the introduction of process gas into the coating cavity is stopped, and then the filament is controlled to stop working.

7. The HWCVD coating process according to claim 4, characterized in that, The first deposition step further includes: Intermittent deposition: After the first time, the deposition is stopped for a second time, and the filament is controlled to work again during the first time, and process gas is introduced into the coating chamber through the gas outlet; The intermittent deposition step is repeated n times, where n≥1.

8. The HWCVD coating process according to claim 7, characterized in that, The step of stopping deposition includes: Control the silk thread to stop working, and after the second time, control the silk thread to start working again; Alternatively, the substrate to be plated can be isolated from the wire, and after the second time, the substrate to be plated can be controlled to return to the working environment of the wire.

9. The HWCVD coating process according to any one of claims 4 to 8, characterized in that, The HWCVD coating process includes: Control the exposure of the P-side of the substrate to be deposited, and perform the first deposition step to form an intrinsic amorphous silicon thin film on the P-side of the substrate to be deposited. The N-side of the substrate to be deposited is exposed, and the first deposition step is performed to form an intrinsic amorphous silicon thin film on the N-side of the substrate to be deposited.

10. The HWCVD coating process according to claim 9, characterized in that, The HWCVD coating process also includes a second deposition step: After the first deposition step is completed, a P-type microcrystalline silicon film is deposited on the intrinsic amorphous silicon film on the P-side of the substrate to be deposited, and an N-type microcrystalline silicon film is deposited on the intrinsic amorphous silicon film on the N-side of the substrate to be deposited.

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