Sputtering apparatus for back contact cells, back contact cells and methods of manufacture

Abstract

This invention relates to the field of solar cell technology, specifically to a sputtering coating apparatus for back-contact solar cells, a back-contact solar cell, and a fabrication method thereof. The sputtering coating apparatus includes, sequentially arranged along the carrier transport direction, an infeed chamber, at least one remote plasma processing chamber, an infeed isolation chamber, an infeed buffer chamber, at least one coating chamber, an outfeed buffer chamber, an outfeed isolation chamber, and an outfeed chamber. By integrating the remote plasma processing chamber into the sputtering coating apparatus, the oxide layer on the back side of the silicon wafer after the opening of the first semiconductor layer and the edge coating are cleaned using a remote plasma processing method, which greatly simplifies the process flow. At the same time, since plasma processing and sputtering coating are integrated into the same apparatus, no additional wet etching cleaning is required before coating, which greatly reduces the risk of damage to the back passivation layer and is beneficial to improving the reliability of the cell.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and in particular to a sputtering coating apparatus, a back contact cell, and a preparation method thereof for a back contact cell. Background Technology

[0002] Currently, in the existing back-contact heterojunction solar cell process, after forming the first semiconductor region opening, the cleaning method used is wet etching to remove the oxide layer in the first semiconductor opening region and the silicon wafer back edge plating generated during the formation of the front antireflection layer (the plating composition is the front antireflection layer). The entire cleaning process requires two wet etching processes, which is not conducive to the protection of the back passivation layer. Moreover, the preparation of the transparent conductive layer needs to be carried out on a separate coating equipment. The entire process is relatively complex and has a long cycle.

[0003] It should be noted that this part of the present invention only provides background technology related to the present invention, and does not necessarily constitute prior art or known technology. Summary of the Invention

[0004] The purpose of this invention is to overcome the technical problems of complex cleaning processes after the preparation of the first semiconductor layer and complex transparent conductive layer preparation processes in existing back contact batteries.

[0005] To achieve the above objectives, in a first aspect, embodiments of the present invention provide a sputtering coating apparatus for a back-contact battery, integrating a remote plasma processing chamber. The sputtering coating apparatus includes: a wafer entry chamber, at least one remote plasma processing chamber, a wafer entry isolation chamber, a wafer entry buffer chamber, at least one coating chamber, a wafer exit buffer chamber, a wafer exit isolation chamber, and a wafer exit chamber arranged sequentially along the carrier plate transport direction, with valves provided between the different types of chambers; a chamber conveying mechanism drives the carrier plate to stay or react in different chambers.

[0006] The remote plasma processing chamber is equipped with a plasma generator for generating etching gas to etch and clean the back side of the back contact battery. The coating chamber is used to deposit a transparent conductive film layer on the back side of the back contact battery after plasma cleaning.

[0007] Optionally, the remote plasma processing chamber is etched using a fluorine-containing gas, wherein hydrogen is incorporated into the fluorine-containing gas.

[0008] Optionally, the fluorine-containing gas includes NF3, CF4, CHF3, C2F6, SF6, or C3F8.

[0009] Optionally, the operating parameters of the remote plasma processing chamber include at least:

[0010] Plasma generator frequency: 13.56MHz;

[0011] Plasma generator power: 2~4KW;

[0012] The processing time is 20~60 seconds;

[0013] The process vacuum degree is 100~200Pa.

[0014] Optionally, the process vacuum degree of the coating chamber is 0.2~1 Pa.

[0015] Optionally, a heating device is provided at the top of the substrate loading chamber to remove moisture and contaminants from the substrate surface;

[0016] And / or, an infrared heating device is provided at the top of the substrate feeding buffer chamber to assist in substrate preheating and temperature maintenance.

[0017] Optionally, a molecular pump is provided at the top of the wafer entry isolation chamber, wafer entry buffer chamber, coating chamber, wafer exit buffer chamber, and wafer exit isolation chamber.

[0018] Secondly, embodiments of the present invention also provide a method for preparing a back contact battery, based on the sputtering coating apparatus as described in the first aspect, the method comprising:

[0019] The S800 uses a sputtering coating device with integrated remote plasma processing capabilities to clean the back of a silicon wafer and deposit a transparent conductive film layer.

[0020] Optionally, in step S800, a sputtering deposition apparatus with integrated remote plasma processing function is used to clean the back side of the silicon wafer and deposit a transparent conductive film layer, including:

[0021] S801, Start the sputtering coating equipment: The carrier plate containing the solar cells to be coated enters the loading chamber, the loading chamber is emptied, the valve of the loading chamber is opened, the carrier plate containing the solar cells to be coated enters the loading chamber, the valve of the loading chamber is closed, and a vacuum is drawn.

[0022] S802, Remote plasma treatment of the back of the solar cell: After the vacuum degree of the cell entry chamber is less than 100Pa, the valve between the cell entry chamber and the remote plasma treatment chamber is opened, and the carrier plate is driven into the remote plasma treatment chamber. The valve between the cell entry chamber and the remote plasma treatment chamber is closed, and the carrier plate is driven to the last remote plasma treatment chamber at a set speed, thereby performing cleaning treatment of the oxide layer and edge plating on the back of the cell.

[0023] S803, Entering the wafer entry isolation chamber: Inert gas is introduced into the wafer entry isolation chamber in advance. After the vacuum level of the wafer entry isolation chamber is the same as that of the remote plasma processing chamber, the valve between the remote plasma processing chamber and the wafer entry isolation chamber is opened, and the carrier plate is driven into the wafer entry isolation chamber. Then the valve between the remote plasma processing chamber and the wafer entry isolation chamber is closed.

[0024] S804, Entering the wafer loading buffer chamber: The wafer loading isolation chamber is evacuated. After the vacuum level of the wafer loading isolation chamber is less than 1 Pa, the valve between the wafer loading isolation chamber and the wafer loading buffer chamber is opened, and the carrier plate is driven into the wafer loading buffer chamber. Then the valve between the wafer loading isolation chamber and the wafer loading buffer chamber is closed.

[0025] S805, sputtering coating: The carrier plate is conveyed to the last coating chamber at a set speed, and a transparent conductive film of a set thickness is deposited on the back of the battery cell on the carrier plate. Then the carrier plate is conveyed to the unloading buffer chamber.

[0026] S806, Entering the film exit isolation chamber: Open the valve between the film exit buffer chamber and the film exit isolation chamber, the carrier plate enters the film exit isolation chamber, and then close the valve between the film exit buffer chamber and the film exit isolation chamber;

[0027] S807, Entering the film output chamber: Open the valve between the film output isolation chamber and the film output chamber, the carrier plate enters the film output chamber, and then close the valve between the film output isolation chamber and the film output chamber;

[0028] S808, Carrier exiting the film exiting chamber: Close the vacuum gate valve of the film exiting chamber, open the venting valve of the film exiting chamber, venting the film exiting chamber, open the door valve of the film exiting chamber, the carrier is conveyed out of the film exiting chamber, then close the venting valve and door valve of the film exiting chamber, and re-vacuum.

[0029] Optionally, before step S800, the method further includes:

[0030] S100 provides a double-sided polished silicon wafer;

[0031] S200: A first semiconductor layer is prepared on the back side of the silicon wafer, the first semiconductor layer comprising a tunneling oxide layer and an N-type doped polysilicon layer;

[0032] S300. A first mask layer is prepared on the first semiconductor layer;

[0033] S400: A first opening is made on the back side of the silicon wafer, the first mask layer and part of the first semiconductor layer are removed, and a second semiconductor region opening is formed;

[0034] S500: The silicon wafer is texturized and cleaned to form a pyramid textured surface on the front side of the silicon wafer, while the first semiconductor layer in the second semiconductor region on the back side of the silicon wafer and the remaining first mask layer are removed to form a silicon wafer with a single-sided texturized and single-sided polished structure.

[0035] S600. A passivation layer and an anti-reflection layer are sequentially deposited on the front side of the silicon wafer, and a second semiconductor layer is deposited on the back side of the silicon wafer. The second semiconductor layer includes an intrinsic amorphous silicon layer and a P-type doped amorphous silicon layer or a microcrystalline silicon layer.

[0036] S700, a second opening is made on the back side of the silicon wafer to form a first semiconductor region that alternates with the second semiconductor region.

[0037] Optionally, after step S800, the method further includes:

[0038] S900: An isolation trench is formed between the first semiconductor region and the second semiconductor region by etching.

[0039] S1000, An insulating ink layer with spaced intervals is formed on the conductive mask layer on the back of the silicon wafer;

[0040] S1100, silver paste gate electrodes are formed on the first semiconductor region and the second semiconductor region of the silicon wafer.

[0041] Thirdly, embodiments of the present invention also provide a back contact battery, which is obtained using the back contact battery preparation method described in the second aspect.

[0042] The embodiments of the present invention have at least the following technical effects:

[0043] The present invention, through the above-mentioned technical solution, integrates a remote plasma processing chamber into a sputtering coating equipment, thereby using remote plasma processing to clean the oxide layer and edge-wrap coating on the back side of the silicon wafer after the opening of the first semiconductor layer. This greatly simplifies the process flow and improves the fabrication efficiency of the solar cells. At the same time, since plasma processing and sputtering coating are integrated into the same equipment, no additional wet etching cleaning is required before coating, which greatly reduces the risk of damage to the back passivation layer and helps to improve the reliability of the solar cells. Attached Figure Description

[0044] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0045] Figure 1 A schematic diagram of the overall structure of a sputtering coating apparatus for a back contact battery provided in an embodiment of the present invention;

[0046] Figure 2 A method for preparing a back contact battery is provided in an embodiment of the present invention;

[0047] Figure 3 This is a schematic diagram of the specific process of step S800 in a method for preparing a back contact battery according to an embodiment of the present invention.

[0048] In the picture:

[0049] 101 - Wafer loading chamber; 102 - First remote plasma processing chamber; 103 - Second remote plasma processing chamber; 104 - Wafer loading isolation chamber; 105 - Wafer loading buffer chamber; 106 - Coating chamber; 107 - Wafer exit buffer chamber; 108 - Wafer exit isolation chamber; 109 - Wafer exit chamber;

[0050] 200 - Carrier plate; 201 - Valve;

[0051] 301 - Plasma gas supply equipment; 302 - Heating equipment; 303 - Infrared heating equipment; 304 - Rotating target holder; 305 - Chamber observation window; 306 - Chamber transfer mechanism; 401 / 402 / 403 / 404 - Combined mechanical pump; 405 - Plasma generator; 406 - Molecular pump. Detailed Implementation

[0052] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0054] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The term “and / or” as used herein includes all or any units and all combinations of one or more associated listed items.

[0055] The first aspect, such as Figure 1 As shown, this embodiment of the invention provides a sputtering coating apparatus for back-contact batteries, integrating a remote plasma processing chamber. The sputtering coating apparatus includes: a wafer entry chamber 101, at least one remote plasma processing chamber (shown as two in the figure, namely a first remote plasma processing chamber 102 and a second remote plasma processing chamber 103), a wafer entry isolation chamber 104, a wafer entry buffer chamber 105, at least one coating chamber 106, a wafer exit buffer chamber 107, a wafer exit isolation chamber 108, and a wafer exit chamber 109, with valves 201 provided between different types of chambers; the chamber conveying mechanism 306 drives the carrier plate 200 to stay or react in different chambers, thereby realizing the preparation of the corresponding process.

[0056] The remote plasma processing chamber (not specifically the first remote plasma processing chamber 102 or the second remote plasma processing chamber 103) is equipped with a plasma generating device, which includes a plasma generator and a plasma gas supply device 301. The plasma generator 405 is used to ionize the gas flowing out of the plasma gas supply device 301 to generate an etching gas (e.g., HF4) to etch and clean the back side of the back contact battery, mainly removing the oxide layer after the opening of the first semiconductor layer and the surrounding coating layer. The coating chamber 106 is used to deposit a transparent conductive film layer on the back side of the back contact battery after plasma cleaning, so that the transparent conductive layer and the previous cleaning process are completed in the same sputtering coating equipment. Optionally, a rotating target 304 is provided in the coating chamber 106 to improve the uniformity of the coating.

[0057] The sputtering coating equipment provided in this embodiment of the invention integrates a remote plasma processing chamber into the sputtering coating equipment, thereby using remote plasma processing to clean the oxide layer and edge-wrapped coating on the back side of the silicon wafer after the opening of the first semiconductor layer. This greatly simplifies the process flow and improves the fabrication efficiency of the solar cells. At the same time, since plasma processing and sputtering coating are integrated into the same equipment, no additional wet etching cleaning is required before coating, which greatly reduces the risk of damaging the back passivation layer and helps to improve the reliability of the solar cells.

[0058] Optionally, the remote plasma processing chamber uses fluorine-containing gas for etching, and hydrogen is incorporated into the fluorine-containing gas. The hydrogen incorporation mainly weakens the etching resistance of the silicon wafer surface, which helps to improve the etching and cleaning effect.

[0059] Optionally, the fluorine-containing gas includes NF3, CF4, CHF3, C2F6, SF6, or C3F8. The fluorine-containing gas flows into the remote plasma processing chamber through the plasma supply equipment. The fluorine-containing gas reacts with O2 plasma generated under the action of the plasma generator 405 to generate highly corrosive fluorides such as HF, thereby achieving the purpose of wet etching and cleaning.

[0060] Optionally, the operating parameters of the remote plasma processing chamber include at least:

[0061] The plasma generator frequency is 13.56MHz or 27.12MHz.

[0062] Plasma generator power: 2~4KW;

[0063] The processing time is 20~60 seconds;

[0064] The process vacuum degree is 100~200Pa.

[0065] It should be noted that too low power and processing time will result in poor cleaning effect and residue, while too high power and processing time may damage the surface of the passivation layer, thereby affecting battery efficiency.

[0066] Optionally, the process vacuum degree of the coating chamber 106 is 0.2~1 Pa.

[0067] Optionally, a heating device 302 is provided on the top of the substrate isolation chamber 104, which is used to remove moisture and contaminants from the substrate surface.

[0068] Optionally, an infrared heating device 303 is provided on the top of the substrate feeding buffer chamber 105, which is used to assist in substrate preheating and temperature maintenance.

[0069] Optionally, a molecular pump 406 (typically with a pressure of up to 10 kJ / L) is provided at the top of the wafer entry isolation chamber 104, the wafer entry buffer chamber 105, the coating chamber 106, the wafer exit buffer chamber 107, and the wafer exit isolation chamber 108. -1 ~10 - 5 These molecular pumps 406 control the vacuum requirements of the corresponding chambers in the order of "atmosphere - low vacuum - high vacuum". In particular, the coating chamber has extremely high vacuum requirements. When the combined mechanical pumps in each chamber cannot meet the vacuum requirements, the molecular pumps are turned on to meet the vacuum requirements.

[0070] Optionally, each chamber is equipped with a chamber observation window 305. The chamber observation window 305 is used to observe the coating condition inside the chamber, facilitating timely repair in case of malfunction, reducing losses, and improving the safety of equipment and products. A vacuum gauge is installed at the position of the chamber observation window 305 to observe and judge the vacuum or pressure conditions inside the chamber, which is beneficial to improving the quality of the coated products.

[0071] Optionally, the sputtering coating equipment provided in this embodiment also includes combined mechanical pumps 401 / 402 / 403 / 404. These combined mechanical pumps are also set from low to high according to the vacuum requirements of the corresponding chambers. They are specifically designed according to the different vacuum requirements of different chambers, which helps to reduce costs and achieve better matching results. The vacuum level that the combined mechanical pumps can achieve is generally around 10. 5 ~10 -1 Pa.

[0072] The second aspect, such as Figure 2 As shown, this embodiment of the invention provides a method for preparing a back contact battery, the complete process steps of which include S100~S1100:

[0073] S100 provides a double-sided polished silicon wafer.

[0074] S200. A first semiconductor layer is prepared on the back side of a silicon wafer. The first semiconductor layer includes a tunneling oxide layer and an N-type doped polysilicon layer.

[0075] Optionally, the thickness of the N-type doped polycrystalline silicon layer is 80-200 nm;

[0076] S300, Prepare a first mask layer on the first semiconductor layer.

[0077] Optionally, the first mask layer is at least one of silicon nitride, silicon oxide, or silicon oxynitride.

[0078] S400. An opening is made on the back side of the silicon wafer for the first time, and the first mask layer and part of the first semiconductor layer are removed to form a second semiconductor region opening.

[0079] Optionally, the width W1 of the opening in the second semiconductor region is 300-700um.

[0080] S500: The silicon wafer is texturized and cleaned to form a pyramid textured surface on the front side of the silicon wafer. At the same time, the first semiconductor layer and the remaining first mask layer in the second semiconductor region on the back side of the silicon wafer are removed to form a silicon wafer with a single-sided texturized and single-sided polished structure.

[0081] S600. A passivation layer and an anti-reflection layer are sequentially deposited on the front side of the silicon wafer, and a second semiconductor layer is deposited on the back side of the silicon wafer. The second semiconductor layer includes an intrinsic amorphous silicon layer and a P-type doped amorphous silicon layer or a microcrystalline silicon layer.

[0082] Optionally, each layer of the second semiconductor layer is deposited using PECVD.

[0083] S700, A second opening is made on the back side of the silicon wafer to form a first semiconductor region that alternates with the second semiconductor region.

[0084] Optionally, the width of the opening in the first semiconductor region is W2, where W2 is 150-350um.

[0085] The S800 uses a sputtering coating device with integrated remote plasma processing capabilities to clean the back of a silicon wafer and deposit a transparent conductive film layer.

[0086] Specifically, step S800 is based on the sputtering coating equipment of the aforementioned embodiment. The equipment first performs plasma etching and cleaning on the oxide layer and the edge coating in the opening of the first semiconductor region, and then completes the sputtering of the transparent conductive film layer. These two processes are completed in the same equipment, reducing one wet etching step, which is beneficial to the protection of the back passivation layer, improving the reliability of the battery, and simplifying the process flow.

[0087] S900: An isolation trench is formed between the first semiconductor region and the second semiconductor region by etching.

[0088] Optionally, the width of the isolation groove is WgL, where WgL is 30-150um.

[0089] S1000: An insulating ink layer with spaced intervals is formed on the conductive mask layer on the back side of the silicon wafer.

[0090] S1100, silver paste gate electrodes are formed on the first semiconductor region and the second semiconductor region of the silicon wafer.

[0091] The back-contact battery fabrication method provided in this invention is based on a sputtering coating equipment with integrated remote plasma cleaning function. This method utilizes remote plasma treatment to clean the oxide layer and edge-wrap coating on the back side of the silicon wafer after the opening of the first semiconductor layer, greatly simplifying the process flow and improving the battery cell fabrication efficiency. At the same time, since plasma treatment and sputtering coating are integrated into the same process equipment, no additional wet etching cleaning is required before coating, greatly reducing the risk of damage to the back passivation layer and improving the reliability of the battery.

[0092] Optionally, such as Figure 3 As shown, in step S800, a sputtering deposition device with integrated remote plasma processing function is used to clean the back side of the silicon wafer and deposit a transparent conductive film layer, specifically including:

[0093] S801, Start the sputtering coating equipment: The carrier plate 200 containing the solar cells to be coated enters the loading chamber 101, the loading chamber 101 is evacuated, the valve 201 of the loading chamber 101 is opened, the carrier plate 200 containing the solar cells to be coated enters the loading chamber 101, the valve 201 of the loading chamber 101 is closed, and a vacuum is drawn.

[0094] S802, Remote plasma treatment of the back of the battery cell: After the vacuum degree of the cell entry chamber 101 is less than 100Pa, the valve 201 between the cell entry chamber 101 and the remote plasma treatment chamber is opened, and the carrier plate 200 is driven into the remote plasma treatment chamber. The valve 201 between the cell entry chamber 101 and the remote plasma treatment chamber is closed, and the carrier plate 200 is driven to the last remote plasma treatment chamber at a set speed, thereby performing cleaning treatment of the oxide layer and edge plating on the back of the battery.

[0095] Specifically, the remote plasma processing chamber has an RF frequency of 13.56MHz, a power of 2-4KW, a processing time of 20-60S, and a vacuum level of 100-200Pa. This step involves etching and cleaning the back of the battery, primarily treating the back oxide layer and the edge coating.

[0096] S803, Entering the wafer entry isolation chamber 104: Inert gas is introduced into the wafer entry isolation chamber 104 in advance. After the vacuum level of the wafer entry isolation chamber is the same as that of the remote plasma processing chamber, the valve 201 between the remote plasma processing chamber and the wafer entry isolation chamber 104 is opened, and the carrier plate 200 is driven into the wafer entry isolation chamber 104. Then the valve 201 between the remote plasma processing chamber and the wafer entry isolation chamber 104 is closed.

[0097] S804, Entering the wafer loading buffer chamber 105: Vacuum treatment is performed on the wafer loading isolation chamber 104. After the vacuum degree of the wafer loading isolation chamber 104 is less than 1 Pa, the valve 201 between the wafer loading isolation chamber 104 and the wafer loading buffer chamber 105 is opened, and the carrier plate 200 is driven into the wafer loading buffer chamber 105. Then the valve 201 between the wafer loading isolation chamber 104 and the wafer loading buffer chamber 105 is closed.

[0098] S805, Sputtering Coating: The carrier plate 200 is conveyed to the last coating chamber 106 at a set speed, and after a transparent conductive film of a set thickness is deposited on the back of the battery cell on the carrier plate 200, the carrier plate 200 is conveyed to the unloading buffer chamber 107.

[0099] S806, Entering the film exit isolation chamber 108: Open the valve 201 between the film exit buffer chamber 107 and the film exit isolation chamber 108, and the carrier plate 200 enters the film exit isolation chamber 108. Then close the valve 201 between the film exit buffer chamber and the film exit isolation chamber.

[0100] S807, Entering the film output chamber 109: Open the valve 201 between the film output isolation chamber 108 and the film output chamber 109, and the carrier plate 200 enters the film output chamber 109. Then close the valve 201 between the film output isolation chamber 108 and the film output chamber 109.

[0101] S808, Carrier plate 200 exits film exit chamber 109: Close the vacuum gate valve of film exit chamber 109, open the venting valve of film exit chamber 109, venting film exit chamber 109, open the gate valve 201 of film exit chamber 109, carrier plate 200 conveys film exit chamber 109, then close the venting valve and gate valve 201 of film exit chamber 109, and re-vacuum.

[0102] Thirdly, embodiments of the present invention also provide a back contact battery, which is obtained by the back contact battery preparation method of the second aspect. The back contact battery uses a sputtering coating equipment with integrated remote plasma cleaning function to complete the back cleaning after the formation of the opening region of the first semiconductor layer and the subsequent preparation of the transparent conductive film layer, thereby reducing one wet etching step.

[0103] The back-contact solar cell provided in this invention uses a sputtering coating equipment with integrated remote plasma cleaning function to clean the oxide layer and edge coating on the back of the silicon wafer after the opening of the first semiconductor layer. Since plasma treatment and sputtering coating are integrated into the same process equipment, the cell manufacturing efficiency is improved. Furthermore, since no additional wet etching cleaning is required before coating, the risk of damage to the back passivation layer is greatly reduced, which is beneficial to improving the reliability of the cell.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a back contact battery, characterized in that, include: S100 provides a double-sided polished silicon wafer; S200: A first semiconductor layer is prepared on the back side of the silicon wafer, the first semiconductor layer comprising a tunneling oxide layer and an N-type doped polysilicon layer; S300. A first mask layer is prepared on the first semiconductor layer; S400: A first opening is made on the back side of the silicon wafer, the first mask layer and part of the first semiconductor layer are removed, and a second semiconductor region opening is formed; S500: The silicon wafer is texturized and cleaned to form a pyramid textured surface on the front side of the silicon wafer, while the first semiconductor layer in the second semiconductor region on the back side of the silicon wafer and the remaining first mask layer are removed to form a silicon wafer with a single-sided texturized and single-sided polished structure. S600. A passivation layer and an anti-reflection layer are sequentially deposited on the front side of the silicon wafer, and a second semiconductor layer is deposited on the back side of the silicon wafer. The second semiconductor layer includes an intrinsic amorphous silicon layer and a P-type doped amorphous silicon layer or a microcrystalline silicon layer. S700, A second opening is made on the back side of the silicon wafer to form a first semiconductor region that alternates with the second semiconductor region; S800 uses a sputtering coating equipment with integrated remote plasma processing capabilities to etch and clean the back side of a silicon wafer and deposit a transparent conductive film layer. The sputtering coating equipment with integrated remote plasma processing function includes: a wafer entry chamber, at least one remote plasma processing chamber, a wafer entry isolation chamber, a wafer entry buffer chamber, at least one coating chamber, a wafer exit buffer chamber, a wafer exit isolation chamber, and a wafer exit chamber arranged sequentially along the carrier plate transport direction, with valves provided between different types of chambers; the carrier plate is driven to stay or react in different chambers by a chamber transport mechanism; a plasma generator is provided in the remote plasma processing chamber to generate etching gas to etch and clean the back side of the back contact battery; the coating chamber is used to deposit a transparent conductive film layer on the back side of the back contact battery after plasma cleaning; the plasma generator includes a plasma generator and a plasma gas supply device; the plasma generator is used to ionize the gas flowing out of the plasma gas supply device to generate etching gas; the remote plasma processing chamber uses fluorine-containing gas for etching treatment, and hydrogen is incorporated into the fluorine-containing gas.

2. The preparation method according to claim 1, characterized in that, In step S800, a sputtering deposition device with integrated remote plasma processing function is used to clean the back side of the silicon wafer and deposit a transparent conductive film layer, including: S801, Start the sputtering coating equipment: The carrier plate containing the solar cells to be coated enters the loading chamber, the loading chamber is emptied, the valve of the loading chamber is opened, the carrier plate containing the solar cells to be coated enters the loading chamber, the valve of the loading chamber is closed, and a vacuum is drawn. S802, Remote plasma treatment of the back of the solar cell: After the vacuum degree of the cell entry chamber is less than 100Pa, the valve between the cell entry chamber and the remote plasma treatment chamber is opened, and the carrier plate is driven into the remote plasma treatment chamber. The valve between the cell entry chamber and the remote plasma treatment chamber is closed, and the carrier plate is driven to the last remote plasma treatment chamber at a set speed, thereby performing cleaning treatment of the oxide layer and edge plating on the back of the cell. S803, Entering the wafer entry isolation chamber: Inert gas is introduced into the wafer entry isolation chamber in advance. After the vacuum level of the wafer entry isolation chamber is the same as that of the remote plasma processing chamber, the valve between the remote plasma processing chamber and the wafer entry isolation chamber is opened, and the carrier plate is driven into the wafer entry isolation chamber. Then the valve between the remote plasma processing chamber and the wafer entry isolation chamber is closed. S804, Entering the wafer loading buffer chamber: The wafer loading isolation chamber is evacuated. After the vacuum level of the wafer loading isolation chamber is less than 1 Pa, the valve between the wafer loading isolation chamber and the wafer loading buffer chamber is opened, and the carrier plate is driven into the wafer loading buffer chamber. Then the valve between the wafer loading isolation chamber and the wafer loading buffer chamber is closed. S805, sputtering coating: The carrier plate is conveyed to the last coating chamber at a set speed, and a transparent conductive film of a set thickness is deposited on the back of the battery cell on the carrier plate. Then the carrier plate is conveyed to the unloading buffer chamber. S806, Entering the film exit isolation chamber: Open the valve between the film exit buffer chamber and the film exit isolation chamber, the carrier plate enters the film exit isolation chamber, and then close the valve between the film exit buffer chamber and the film exit isolation chamber; S807, Entering the film output chamber: Open the valve between the film output isolation chamber and the film output chamber, the carrier plate enters the film output chamber, and then close the valve between the film output isolation chamber and the film output chamber; S808, Carrier exiting the film exiting chamber: Close the vacuum gate valve of the film exiting chamber, open the venting valve of the film exiting chamber, venting the film exiting chamber, open the door valve of the film exiting chamber, the carrier is conveyed out of the film exiting chamber, then close the venting valve and door valve of the film exiting chamber, and re-vacuum.

3. The preparation method according to claim 2, characterized in that, Following step S800, the method further includes: S900: An isolation trench is formed between the first semiconductor region and the second semiconductor region by etching. S1000, An insulating ink layer with spaced intervals is formed on the conductive mask layer on the back of the silicon wafer; S1100, silver paste gate electrodes are formed on the first semiconductor region and the second semiconductor region of the silicon wafer.

4. The preparation method according to claim 1, characterized in that, The fluorine-containing gas includes NF3, CF4, CHF3, C2F6, SF6, or C3F8.

5. The preparation method according to claim 1, characterized in that, The operating parameters of the remote plasma processing chamber include at least the following: Plasma generator frequency: 13.56MHz; Plasma generator power: 2~4kW; The processing time is 20~60 seconds; The process vacuum degree is 100~200Pa.

6. The preparation method according to claim 1, characterized in that, The process vacuum degree of the coating chamber is 0.2~1 Pa.

7. The preparation method according to claim 1, characterized in that, The top of the substrate loading chamber is equipped with a heating device to remove moisture and contaminants from the substrate surface; And / or, an infrared heating device is provided at the top of the substrate feeding buffer chamber to assist in substrate preheating and temperature maintenance.

8. The preparation method according to claim 1, characterized in that, Molecular pumps are installed at the top of the wafer entry isolation chamber, wafer entry buffer chamber, coating chamber, wafer exit buffer chamber, and wafer exit isolation chamber.

9. A back-contact battery, characterized in that, It is obtained using the method for preparing a back contact battery as described in claim 3.

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