A PECVD device with adjustable inter-electrode spacing

Abstract

The present invention discloses a PECVD apparatus with adjustable inter-electrode spacing, comprising a chamber and a chamber cover. The chamber cover is hinged to the chamber top, with a mounting plate provided inside the chamber cover. A spray plate is provided at the bottom of the mounting plate, forming a uniform flow chamber between the spray plate and the mounting plate. An air inlet is provided on the mounting plate, and an RF power supply is provided outside the chamber cover, connected to the air inlet via a first conductive element. An inlet and outlet are provided on the chamber sidewalls. A heating plate is provided within the chamber, with a carrier plate positioned between the spray plate and the heating plate. A support plate is provided below the heating plate, with support rods provided on the support plate, which pass through the heating plate to support the carrier plate. The chamber bottom is connected to a lifting drive installation chamber via a three-way interface, the third interface of the three-way interface being connected to a vacuum pump. The lifting drive installation chamber houses a first lifting drive device for lifting the support plate and a second lifting drive device for lifting the heating plate. The present invention has the advantages of good film uniformity and a larger process window.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor preparation, and in particular to a PECVD device with adjustable inter-electrode spacing. Background Art

[0002] PECVD equipment is primarily used for the deposition of I / N / P film layers in heterojunction cells. Its principle is to use parallel plate discharge to provide energy, energizing the reactant gases into a plasma. The cell is then laid flat on a carrier plate and placed between the parallel plates. The reactant gases chemically react to form a film layer on the cell. Further improving the efficiency of heterojunction cells is to use doped microcrystalline silicon instead of the current doped amorphous silicon. This can further increase the doping concentration, improve light transmittance, reduce the resistance of the doped layer, and ultimately increase the current density of the heterojunction cell. Because VHF (very high frequency) excited plasma has a lower electron temperature and higher density than conventional RF plasma, it can significantly increase the deposition rate of thin films. Currently, VHF-PECVD is primarily used for the deposition of microcrystalline silicon. However, the standing wave effect generated by VHF can cause uneven film thickness, resulting in generally poor film thickness uniformity in VHF-PECVD.

[0003] Currently, PECVD equipment typically comes in two types: 1) Magnetic fluid is placed on either side of the chamber, and the carrier is rolled over the fluid to be transported into the process chamber. A heating plate is positioned below the carrier, and a spray plate is positioned above. The spacing between the plates remains constant, and a voltage is applied between the plates to perform discharge coating. 2) A linear robotic arm is used to transport the carrier, with no magnetic fluid surrounding the chamber. After the robotic arm transports the carrier to the top of the heating plate, a lift rod at the bottom of the chamber passes through the heating plate to lift the carrier, facilitating the robotic arm's retraction. Similarly, the heating plate is positioned below the carrier, and the spray plate is positioned above the carrier. The spacing between the plates remains constant, and a voltage is applied between the plates to perform discharge coating. The ferrofluid placement on both sides of the first type disrupts the symmetry of the chamber, exacerbating the uneven electromagnetic field inside the chamber and causing uneven coating. Furthermore, the carrier is transported across the magnetic fluid, requiring reinforcement ribs at the bottom of the carrier. These ribs can result in inadequate contact between the carrier and the heating plate, affecting temperature uniformity and, consequently, film thickness uniformity. Furthermore, the plate spacing of both devices is not adjustable, resulting in a narrow process window during the coating process, making them unsuitable for coating with complex, multi-gas types. Furthermore, both chambers utilize a single-point feed method, located in the center of the top of the spray plate, which prevents adjustment of film thickness uniformity. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a PECVD device with good coating uniformity, an enlarged process window and adjustable inter-electrode spacing.

[0005] A PECVD device with adjustable inter-electrode spacing comprises a chamber and a chamber cover, the chamber cover being hingedly connected to the top of the chamber, a mounting plate being provided on the inner side of the chamber cover, a spray electrode plate being provided at the bottom of the mounting plate, a uniform flow chamber being formed between the spray electrode plate and the mounting plate, an air intake device being provided on the mounting plate for ejecting air into the uniform flow chamber, a radio frequency power supply being provided on the outer side of the chamber cover, the radio frequency power supply being connected to the air intake device through a first conductive element, an inlet and outlet being provided on the side wall of the chamber for a carrier plate to enter the chamber, a heating electrode plate being provided in the chamber, the carrier plate being located between the spray electrode plate and the heating electrode plate, a support plate being provided under the heating electrode plate, a support rod being provided on the support plate, the support rod passing through the heating electrode plate for supporting the carrier plate, the bottom of the chamber being connected to a lifting drive device installation chamber through a three-way interface, the third interface of the three-way interface being connected to a vacuum pump, and a first lifting drive device for driving the support plate to lift and lower, and a second lifting drive device for driving the heating electrode plate to lift and lower, being provided in the lifting drive device installation chamber.

[0006] As a further improvement of the above technical solution:

[0007] The first lifting drive device includes a first movable component and a telescopic cylinder for driving the first movable component to lift and lower. The telescopic cylinder is arranged on the lifting drive device installation chamber. The first movable component passes through the top of the lifting drive device installation chamber, the three-way interface and the bottom of the cavity in sequence to be connected to the support plate.

[0008] A guide rail is provided on the inner side wall of the installation chamber of the lifting drive device, and a first sliding block is provided on the first movable component. The first sliding block is slidably arranged on the guide rail.

[0009] The second lifting drive device includes a second movable component, a screw rod and a driving mechanism for driving the screw rod to rotate. The screw rod is threaded with a screw nut, and the screw nut is arranged on the second movable component. The second movable component is provided with a second slider, which is slid on the guide rail and is located below the first slider. The second movable component passes through the first movable component and is connected to the heating plate.

[0010] The air intake device includes an air intake column and an air intake pipe. The air intake column is arranged on the mounting plate and is connected to the flow-uniform cavity. The air intake pipe passes through the top of the cavity cover and is connected to the air intake column.

[0011] A flow equalizer plate is provided at the bottom of the air intake column, and the flow equalizer plate is arranged in the flow equalizer cavity.

[0012] A plurality of second conductive elements are provided between the air intake column and the mounting plate. The plurality of second conductive elements are arranged at intervals along the circumferential direction of the air intake column with the air intake column as the center.

[0013] A pull rod is also provided between the mounting plate and the spray electrode plate.

[0014] A rectifier plate is provided in the cavity, and the rectifier plate is located between the spray plate and the carrier plate.

[0015] A heating element is provided in each side wall of the cavity.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The PECVD equipment with adjustable inter-electrode spacing disclosed in the present invention forms a uniform flow chamber between the mounting plate and the spray plate. An air inlet device ejects air into the uniform flow chamber, which is sprayed onto the carrier plate through the spray plate. At the same time, the carrier plate is heated by the heating plate. The reaction chamber formed by the cavity body and the cavity cover is evacuated by a vacuum pump to form a vacuum environment required for the process. At this time, the RF power supply outputs RF electricity to the two plates through the first conductive element, and the battery cells on the carrier plate can be electroplated. The carrier plate and the heating plate can be freely lifted and lowered by the first lifting drive device and the second lifting drive device, and the spacing between the heating plate and the spray plate can be adjusted to increase the process window. It is applicable to various types of gas coating, and there is no need to set up a magnetic fluid to transport the carrier plate, which will not destroy the symmetry of the cavity and avoid affecting the uniformity of the electromagnetic field in the cavity. The heating plate can fully fit the carrier plate, and the temperature uniformity is good, thereby improving the coating uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic cross-sectional view of the PECVD device with adjustable inter-electrode spacing according to the present invention.

[0019] Figure 2 Schematic diagram of the structure inside the cavity cover of the present invention.

[0020] Figure 3 Schematic diagram of the structure inside the cavity of the present invention.

[0021] Figure 4 This is a schematic diagram of the structure of the lifting drive device installed in the room of the present invention.

[0022] The numbers in the figure represent: 1. cavity; 2. cavity cover; 3. mounting plate; 4. spray plate; 5. uniform flow chamber; 6. air inlet device; 7. RF power supply; 8. first conductive element; 9. carrier plate; 10. inlet and outlet; 11. heating plate; 12. support plate; 13. support rod; 14. three-way interface; 15. lifting drive device installation chamber; 16. vacuum pump; 17. first lifting drive device; 18. second lifting drive device; 19. first movable component; 20. telescopic cylinder; 21. guide rail ; 22. First slider; 23. Second movable component; 24. Screw; 25. Drive mechanism; 26. Screw nut; 27. Second slider; 28. Intake column; 29. ​​Intake pipe; 30. Flow equalizer; 31. Second conductive element; 32. Pull rod; 33. Rectifier plate; 34. Heating element; 35. Drive motor; 36. Driving wheel; 37. Driven wheel; 38. Synchronous belt; 39. Screw mounting seat; 40. Support column; 41. Insulating member; 42. Bellows; 43. Rotating hinge. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] As shown in this disclosure and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" are not limited to the singular and may also include the plural. Similarly, words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, but do not exclude other elements or objects. Words such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0025] Figures 1 to 4An embodiment of the present invention is shown. The PECVD device with adjustable inter-electrode spacing in this embodiment includes a chamber 1 and a chamber cover 2. The chamber cover 2 is hinged to the top of the chamber 1. A mounting plate 3 is provided on the inner side of the chamber cover 2. A spray electrode plate 4 is provided at the bottom of the mounting plate 3. A uniform flow chamber 5 is formed between the spray electrode plate 4 and the mounting plate 3. An air inlet device 6 for spraying air into the uniform flow chamber 5 is provided on the mounting plate 3. A radio frequency power supply 7 is provided on the outer side of the chamber cover 2. The radio frequency power supply 7 is connected to the air inlet device 6 through a first conductive element 8. An inlet and outlet 10 for a carrier plate 9 to enter the chamber 1 is provided on the side wall of the chamber 1. The chamber 1 A heating plate 11 is provided inside, and a carrier plate 9 is located between the spray plate 4 and the heating plate 11. A support plate 12 is provided under the heating plate 11, and a support rod 13 is provided on the support plate 12. The support rod 13 passes through the heating plate 11 to support the carrier plate 9. The bottom of the cavity 1 is connected to the lifting drive device installation chamber 15 through a three-way interface 14. The third interface of the three-way interface 14 is connected to the vacuum pump 16. The lifting drive device installation chamber 15 is provided with a first lifting drive device 17 for driving the support plate 12 to rise and fall, and a second lifting drive device 18 for driving the heating plate 11 to rise and fall.

[0026] In this PECVD equipment with adjustable inter-electrode spacing, a uniform flow chamber 5 is formed between the mounting plate 3 and the spray electrode plate 4. The air inlet device 6 sprays air into the uniform flow chamber 5, and is sprayed onto the carrier plate 9 through the spray electrode plate 4. At the same time, the carrier plate 9 is heated by the heating electrode plate 11. The reaction chamber formed by the cavity 1 and the cavity cover 2 is evacuated by the vacuum pump 16 to form the vacuum environment required for the process. At this time, the RF power supply 7 outputs RF electricity to the two electrode plates through the first conductive element 8, and the battery cell on the carrier plate 9 can be electroplated. The placement process of the carrier 9 before coating is as follows: the manipulator sends the carrier 9 into the cavity 1 through the inlet and outlet 10 on the side wall of the cavity 1, and the first lifting drive device 17 drives the support plate 12 and the support rod 13 to rise until the support rod 13 supports the carrier 9, and the manipulator withdraws from the cavity 1, and then the second lifting drive device 18 drives the heating electrode 11 to rise until it contacts the carrier 9. The process of taking out the carrier 9 is the opposite, which will not be repeated here. The first lifting drive device 17 and the second lifting drive device 18 can realize the free lifting and lowering of the carrier 9 and the heating electrode 11, adjust the distance between the heating electrode 11 and the spray electrode 4, increase the process window, and can be applied to multiple types of gas coating, and there is no need to set up magnetic fluid to transport the carrier 9, which will not destroy the symmetry of the cavity 1 and avoid affecting the uniformity of the electromagnetic field in the cavity 1, and the heating electrode 11 can fully fit the carrier 9, with good temperature uniformity, thereby improving the coating uniformity. Preferably, the chamber cover 2 and chamber body 1 are connected by a rotating hinge 43, allowing for lid opening and closing operations via an external electric or pneumatic cylinder. The spray plate 10 is provided with multiple spray holes spaced along its length, ensuring a more uniform spray. Sealing rings are installed at the interconnections between the chamber cover 2, chamber body 1, three-way interface 14, and lift drive mounting chamber 15, ensuring a vacuum environment within the interior space under the action of the vacuum pump 16.

[0027] In this embodiment, the first lifting drive device 17 includes a first movable assembly 19 and a telescopic cylinder 20 for driving the first movable assembly 19 upward and downward. The telescopic cylinder 20 is mounted on the lifting drive device mounting chamber 15. The first movable assembly 19 passes through the top of the lifting drive device mounting chamber 15, the three-way interface 14, and the bottom of the cavity 1 to connect to the support plate 12. The telescopic cylinder 20 drives the first movable assembly 19 upward and downward, thereby driving the support plate 12 and support rod 13 upward and downward, thereby achieving the lifting and lowering of the carrier plate 9. The structure is simple and compact.

[0028] In this embodiment, a guide rail 21 is provided on the inner wall of the lift drive installation chamber 15, and a first slider 22 is provided on the first movable assembly 19. The first slider 22 slides on the guide rail 21. When the telescopic cylinder 20 drives the first movable assembly 19 to move upward or downward, the first movable assembly 19 slides on the guide rail 21 via the first slider 22, providing guidance for the lift and improving lift stability.

[0029] In this embodiment, the second lifting drive device 18 includes a second movable component 23, a screw rod 24, and a driving mechanism 25 for driving the screw rod 24 to rotate. The screw rod 24 is threadedly connected to a screw nut 26, which is provided on the second movable component 23. The second movable component 23 is provided with a second slider 27, which is slidably provided on the guide rail 21 and is located below the first slider 22. The second movable component 23 passes through the first movable component 19 and is connected to the heating plate 11. The driving mechanism 25 drives the screw rod 24 to rotate, driving the screw nut 26 and the second movable component 23 to slide on the guide rail 21 through the second slider 27, thereby achieving the lifting and lowering of the second movable component 23, thereby driving the heating plate 11 to lift and lower. Of course, in other embodiments, other guide rails 21 can also be provided on the inner wall of the lifting drive device installation chamber 15 to provide guidance for the second slider 27.

[0030] In this embodiment, the driving mechanism 25 includes a driving motor 35, a driving wheel 36, a driven wheel 37 and a synchronous belt 38 wound around the driving wheel 36 and the driven wheel 37. The driving motor 35 and the screw rod 24 are respectively connected to the driving wheel 36 and the driven wheel 37. The other end of the screw rod 24 is arranged on the inner wall of the lifting drive device installation chamber 15 through a screw rod mounting seat 39.

[0031] In this embodiment, bellows 42 are provided between the second movable component 23 and the first movable component 19, and between the first movable component 19 and the lifting drive device installation chamber 15, which can not only ensure the free lifting and lowering of the first movable component 19 and the second movable component 23, but also ensure the sealing, which is conducive to maintaining the vacuum environment in the cavity 1.

[0032] In this embodiment, the air inlet device 6 includes an air inlet column 28 and an air inlet pipe 29. The air inlet column 28 is mounted on the mounting plate 3 and communicates with the uniform flow chamber 5. The air inlet pipe 29 passes through the top of the chamber cover 2 and connects to the air inlet column 28. The process gas enters the air inlet column 28 through the air inlet pipe 29, then enters the uniform flow chamber 5. After being uniformly circulated in the uniform flow chamber 5, it is sprayed onto the carrier plate 9 through the spray plate 4, improving gas uniformity and film uniformity.

[0033] In this embodiment, a flow plate 30 is provided at the bottom of the air inlet column 28, and the flow plate 30 is provided in the flow chamber 5. The gas in the air inlet column 28 first passes through the flow plate 30 for a first uniform flow and then enters the flow chamber 5 for a second uniform flow, further improving the gas uniformity and the coating uniformity.

[0034] In this embodiment, multiple second conductive elements 31 are disposed between the inlet column 28 and the mounting plate 3. These elements 31 are spaced apart along the circumference of the inlet column 28, centered around the inlet column 28. Energy from the RF power source 7 is fed into the center of the inlet column 28 via the first conductive element 8. Energy can also be fed evenly through the multiple second conductive elements 31. Compared to single-point feeding, this improves the uniformity of the electric field and, consequently, the uniformity of the coating. Preferably, both the first conductive element 8 and the second conductive element 31 are copper bars.

[0035] In this embodiment, a tie rod 32 is further provided between the mounting plate 3 and the spray plate 4. Preferably, the tie rod 32 is an aluminum alloy tie rod, which can adjust the deformation of the spray plate 4 under gravity and guide the current into the spray plate 4, thereby further improving the uniformity of the coating.

[0036] In this embodiment, a rectifier plate 33 is provided within the chamber 1 and is located between the spray plate 4 and the carrier plate 9. The rectifier plate 33 is supported within the chamber 1 by support columns 40. When the carrier plate 9 rises and contacts the rectifier plate 33, it lifts the rectifier plate 33 together. A hole is opened in the middle of the rectifier plate 33. This does not hinder the spray plate 4 from spraying air toward the carrier plate 9, while also improving the uniformity of the airflow around the carrier plate 9 during the vacuum pump 16's extraction, thereby further improving the uniformity of the coating.

[0037] In this embodiment, heating elements 34 are provided in each side wall of the cavity 1 to improve the temperature uniformity in the cavity 1 , thereby further improving the coating uniformity.

[0038] In this embodiment, an insulating member 41 is provided between the air inlet pipe 29 and the air inlet column 28 and between the mounting plate 3 and the cavity cover 2 to ensure that the mounting plate 3 and the air inlet column 28 are insulated from other components and only feed in radio frequency current.

[0039] Although the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, utilize the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A PECVD device with adjustable inter-electrode spacing, comprising a chamber (1) and a chamber cover (2), wherein the chamber cover (2) is hinged to the top of the chamber (1), and is characterized in that: A mounting plate (3) is provided on the inner side of the cavity cover (2), a spray plate (4) is provided on the bottom of the mounting plate (3), a uniform flow cavity (5) is formed between the spray plate (4) and the mounting plate (3), an air intake device (6) for ejecting air into the uniform flow cavity (5) is provided on the mounting plate (3), a radio frequency power supply (7) is provided on the outer side of the cavity cover (2), the radio frequency power supply (7) is connected to the air intake device (6) via a first conductive element (8), an inlet and outlet (10) for the carrier plate (9) to enter the cavity (1) is provided on the side wall of the cavity (1), a heating plate (11) is provided in the cavity (1), the carrier plate (9) is located between the spray plate (4) and the heating plate (11), a support plate (12) is provided below the heating plate (11), a support rod (13) is provided on the support plate (12), and the support rod (13) passes through the heating electrode (11) to support the carrier plate (9), the bottom of the cavity (1) is connected to the lifting drive device installation chamber (15) through the three-way interface (14), the third interface of the three-way interface (14) is connected to the vacuum pump (16), and the lifting drive device installation chamber (15) is provided with a first lifting drive device (17) for driving the support plate (12) to rise and fall and a second lifting drive device (18) for driving the heating electrode (11) to rise and fall. The first lifting drive device (17) and the second lifting drive device (18) are used to realize the free lifting of the carrier plate (9) and the heating electrode (11) to adjust the distance between the heating electrode (11) and the spray electrode (4). The first lifting drive device (17) and the second lifting drive device (18) are both provided through the three-way interface (14).

2. The PECVD device with adjustable inter-electrode spacing according to claim 1, characterized in that: The first lifting drive device (17) includes a first movable component (19) and a telescopic cylinder (20) for driving the first movable component (19) to lift and lower. The telescopic cylinder (20) is arranged on the lifting drive device installation chamber (15). The first movable component (19) passes through the top of the lifting drive device installation chamber (15), the three-way interface (14) and the bottom of the cavity (1) in sequence to be connected to the support plate (12).

3. The PECVD device with adjustable inter-electrode spacing according to claim 2, characterized in that: A guide rail (21) is provided on the inner side wall of the lifting drive device installation chamber (15), and a first slider (22) is provided on the first movable component (19), and the first slider (22) is slidably mounted on the guide rail (21).

4. The PECVD device with adjustable inter-electrode spacing according to claim 3, characterized in that: The second lifting drive device (18) includes a second movable component (23), a screw rod (24) and a driving mechanism (25) for driving the screw rod (24) to rotate, wherein a screw rod nut (26) is threadedly connected to the screw rod (24), and the screw rod nut (26) is arranged on the second movable component (23). The second movable component (23) is provided with a second slider (27), and the second slider (27) is slidably arranged on the guide rail (21) and is located below the first slider (22). The second movable component (23) passes through the first movable component (19) and is connected to the heating plate (11).

5. The PECVD device with adjustable inter-electrode spacing according to any one of claims 1 to 4, characterized in that: The air intake device (6) comprises an air intake column (28) and an air intake pipe (29). The air intake column (28) is arranged on the mounting plate (3) and is in communication with the flow-uniform cavity (5). The air intake pipe (29) passes through the top of the cavity cover (2) and is connected to the air intake column (28).

6. The PECVD device with adjustable inter-electrode spacing according to claim 5, characterized in that: A flow equalizer plate (30) is provided at the bottom of the air inlet column (28), and the flow equalizer plate (30) is provided in the flow equalizer cavity (5).

7. The PECVD device with adjustable inter-electrode spacing according to claim 6, characterized in that: A plurality of second conductive elements (31) are provided between the air intake column (28) and the mounting plate (3), and the plurality of second conductive elements (31) are arranged at intervals along the circumferential direction of the air intake column (28) with the air intake column (28) as the center.

8. The PECVD device with adjustable inter-electrode spacing according to any one of claims 1 to 4, characterized in that: A pull rod (32) is further provided between the mounting plate (3) and the spray electrode plate (4).

9. The PECVD device with adjustable inter-electrode spacing according to any one of claims 1 to 4, characterized in that: A rectifier plate (33) is provided in the cavity (1), and the rectifier plate (33) is located between the spray plate (4) and the carrier plate (9).

10. The PECVD device with adjustable inter-electrode spacing according to any one of claims 1 to 4, characterized in that: A heating element (34) is provided in each side wall of the cavity (1).

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