Device for improving tubular PECVD (Plasma Enhanced Chemical Vapor Deposition) gas uniformity

By setting up the central air intake pipe and jet nozzle in the tube PECVD equipment, the problem of airflow disorder caused by the disruption of the double boat cut-off during the flow process is solved, which significantly improves the gas uniformity and film uniformity of the rear boat, and improves the coating quality of the crystalline silicon solar cell.

CN222990205UActive Publication Date: 2025-06-17JIANGSU RUNERGY CENTURY PHOTOVOLTAIC TECH CO LTD
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Patent Information

Application Number
CN202421710825.8
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-07-19
Publication Date
2025-06-17
Estimated Expiration
2034-07-19

AI Technical Summary

Technical Problem

In the existing tubular PECVD technology, the gas is disrupted during the flow process due to the truncated position of the double boat, resulting in the airflow of the rear boat, which is poor uniformity, affecting the uniformity of the film layer.

Method used

The central air intake pipe is set up in the center of the top of the double-boat furnace tube. The two intake ends of the central air intake pipe are connected to the special-gas intake pipe and the nitrogen intake pipe respectively. The outlet end is directly opposite the front of the rear boat of the graphite boat, and a jet nozzle and a breach blade are set up in the central air intake pipe. Through the design of the jet nozzle and a breach blade, the uniformity of the gas is improved.

Benefits of technology

By adding the central intake pipe and jet nozzle, the gas uniformity of the rear boat is significantly improved, the uniformity of the film layer is optimized, and the coating quality of crystalline silicon solar cells is improved.

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Abstract

The utility model relates to the technical field of crystalline silicon solar cell production, and discloses a device for improving tubular PECVD (Plasma Enhanced Chemical Vapor Deposition) gas uniformity, which comprises a middle gas inlet pipeline connected to the center of the top of a double-boat furnace tube; two gas inlet ends of the middle gas inlet pipeline are respectively connected with the special gas inlet pipeline and the nitrogen inlet pipeline, and a gas outlet end of the middle gas inlet pipeline is opposite to the front part of the rear boat of the graphite boat in the double-boat furnace tube. A special gas inlet pipeline and a nitrogen inlet pipeline are intersected at a middle gas inlet pipeline, and the middle gas inlet pipeline is arranged in the center of the top of the double-boat furnace tube and is aligned with the front part of a rear boat; a middle gas inlet pipeline is additionally arranged in the furnace, so that the gas uniformity of the rear boat is better, and the film layer uniformity of the rear boat is optimized; according to the device, the furnace door of the tubular PECVD equipment is simple and operable to modify, and the cost is low; and the production capacity is not influenced, and the coating uniformity of the crystalline silicon battery can be remarkably improved, so that a larger space is provided for further improving the efficiency of the battery.
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Description

Technical Field

[0001] The utility model relates to the technical field of crystalline silicon solar cell production, and specifically, to a device for improving the gas uniformity of tube PECVD. Background Art

[0002] The technology for industrial production of crystalline silicon solar cells is becoming increasingly mature. However, with the increasingly fierce market competition, the quality requirements of customers for solar cells are constantly rising. As a kind of solar cell based on the tunneling oxide passivated contact principle of selective carriers, the film thickness uniformity of the tunneling layer and the poly layer is particularly important for TOP-CON cells.

[0003] PECVD technology is to generate glow discharge on the cathode (i.e., the tray where the sample is placed) in the process chamber under low pressure by using low-temperature plasma, and use the glow discharge (or an additional heating element) to heat the sample to a predetermined temperature, and then introduce an appropriate amount of process gas. These gases undergo a series of chemical reactions and plasma reactions, and finally form a solid film on the surface of the sample.

[0004] Therefore, optimizing the gas uniformity of PECVD is of great significance to the film layer uniformity. In actual production, most enterprises choose to optimize a series of process parameters of tube PECVD, but the effect is very little.

[0005] Currently, taking the graphite boat with 12 slots (the rear boat corresponds to slots 7 - 12) in a single slot of PECVD as an example, analyzing its uniformity data, it is found that the uniformity of slots 7 - 12 in the rear boat is significantly worse than that in the front boat. The gas enters at the bottom of the furnace mouth and is pumped at the rear of the furnace tail. The gas flow direction is from the front boat to the rear boat. Because the graphite boat has good toughness but is easy to deform, if the form of combining two boats is used, it is easy to cause the deformation of the graphite boat, and further cause problems such as abnormal insertion of wafers at automated positions, chip fragmentation, and misalignment and deformation of the clamping points; however, if the form of two boats is adopted, it will cause the gas to be disrupted at the truncation of the two boats during the flow process, resulting in disordered gas flow in the rear boat and poor uniformity.

[0006] Therefore, it is necessary to propose a device for improving the gas uniformity of tube PECVD to solve the problems existing in the prior art. Summary of the Utility Model

[0007] A series of simplified concepts are introduced in the summary of the utility model, which will be further described in detail in the specific implementation part. The summary of the utility model does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

[0008] To solve the above problems, the utility model discloses a device for improving the gas uniformity of tube PECVD, which includes:

[0009] The middle air inlet pipe is connected to the center of the top of the double-boat furnace tube; the two air inlet ends of the middle air inlet pipe are respectively connected to the special gas inlet pipe and the nitrogen inlet pipe, and the air outlet end of the middle air inlet pipe faces the front of the rear boat of the graphite boat in the double-boat furnace tube.

[0010] Preferably, a graphite boat front boat and a graphite boat rear boat are respectively arranged in front of and behind the double-boat furnace tube.

[0011] Preferably, the graphite boat front boat is arranged close to the furnace mouth of the double-boat furnace tube, the graphite boat rear boat is arranged close to the furnace tail of the double-boat furnace tube, the air inlet pipe of the double-boat furnace tube is arranged at the bottom of the furnace mouth, and the air outlet pipe is arranged at the furnace tail.

[0012] Preferably, any one or a combination of silane, phosphine, hydrogen, and nitrous oxide is introduced into the special gas inlet pipe.

[0013] Preferably, a jet nozzle is connected to the air outlet end of the middle air inlet pipe.

[0014] Preferably, the jet nozzle is set as a T-shaped jet nozzle, and a plurality of spray openings are uniformly arranged at the bottom of the jet nozzle.

[0015] Preferably, the aperture of the spray opening is set to 3-5 mm.

[0016] Preferably, a sealing ring is arranged at the connection between the middle air inlet pipe and the double-boat furnace tube.

[0017] Preferably, a mixing chamber is arranged at the center inside the middle air inlet pipe, a first air inlet and a second air inlet are respectively arranged at the top end and the side end of the middle air inlet pipe, the first air inlet is connected to the special gas inlet pipe, and the second air inlet is connected to the nitrogen inlet pipe; a mixing air outlet pipe is arranged at the bottom end of the middle air inlet pipe, and the mixing air outlet pipe is connected to the jet nozzle;

[0018] A rotating shaft is connected to the top end of the mixing chamber, and a swirling vane is rotatably connected to the rotating shaft, and the swirling vane is located above the second air inlet;

[0019] A plurality of layers of baffle vanes are uniformly connected inside the mixing air outlet pipe, the baffle vanes are arranged obliquely, and the inclination directions of the baffle vanes in adjacent layers are opposite.

[0020] Compared with the prior art, the present utility model has at least the following beneficial effects:

[0021] An apparatus for improving the gas uniformity in a tube-type PECVD provided in this embodiment converges a special gas inlet pipe and a nitrogen inlet pipe into a middle inlet pipe. The middle inlet pipe is arranged at the center of the top of a double-boat furnace tube and aligned with the front part of the rear boat. Adding a middle inlet pipe in the furnace makes the gas uniformity of the rear boat better and optimizes the film layer uniformity of the rear boat. This apparatus has a simple and operable modification to the furnace door of the tube-type PECVD equipment and low cost. It neither affects production capacity nor can significantly improve the coating uniformity of crystalline silicon cells, thus providing more room for further improving the efficiency of the cells.

[0022] An apparatus for improving the gas uniformity in a tube-type PECVD according to the present utility model. Other advantages, objectives, and features of the present utility model will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is a schematic structural diagram of the present utility model;

[0025] Figure 2 It is a schematic structural diagram of the bottom surface of the air jet nozzle in the present utility model;

[0026] Figure 3 It is a schematic cross-sectional structural diagram of the middle inlet pipe in the present utility model;

[0027] Figure 4 It is a schematic structural diagram of the swirl vane in the present utility model.

[0028] In the figure: 1. Double-boat furnace tube; 2. Middle inlet pipe; 3. Special gas inlet pipe; 4. Nitrogen inlet pipe; 5. Inlet pipe; 6. Outlet pipe; 7. Air jet nozzle; 11. Mixing chamber; 12. First inlet; 13. Second inlet; 14. Mixed outlet pipe; 15. Rotating shaft; 16. Swirl vane; 17. Baffle vane. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts belong to the scope of protection of the present utility model.

[0030] Embodiment

[0031] The present utility model will be further described below in conjunction with the accompanying drawings.

[0032] As Figure 1 、 2 shown, a device for improving the gas uniformity of a tube-type PECVD provided in this embodiment includes:

[0033] A middle air inlet pipe 2, and the middle air inlet pipe 2 is connected to the center of the top of the double-boat furnace tube 1; the two air inlet ends of the middle air inlet pipe 2 are respectively connected to a special gas inlet pipe 3 and a nitrogen inlet pipe 4, and the air outlet end of the middle air inlet pipe 2 faces the front part of the rear boat of the graphite boat in the double-boat furnace tube 1.

[0034] A graphite boat front boat and a graphite boat rear boat are respectively arranged in the front and rear of the double-boat furnace tube 1.

[0035] The graphite boat front boat is arranged close to the furnace mouth of the double-boat furnace tube 1, the graphite boat rear boat is arranged close to the furnace tail of the double-boat furnace tube 1, the air inlet pipe 5 of the double-boat furnace tube 1 is arranged at the bottom of the furnace mouth, and the air outlet pipe 6 is arranged at the furnace tail.

[0036] Any one or a combination of silane, phosphine, hydrogen, and nitrous oxide is introduced into the special gas inlet pipe 3.

[0037] An air jet nozzle 7 is connected to the air outlet end of the middle air inlet pipe 2.

[0038] The air jet nozzle 7 is set as a T-shaped air jet nozzle, and a plurality of air spray nozzles are uniformly arranged at the bottom of the air jet nozzle 7.

[0039] The aperture of the air spray nozzle is set to 3-5 mm.

[0040] A sealing ring is arranged at the connection between the middle air inlet pipe 2 and the double-boat furnace tube 1.

[0041] The working principle of the present utility model is:

[0042] An apparatus for improving the gas uniformity of a tube-type PECVD provided in this embodiment converges a special gas inlet pipe 3 and a nitrogen inlet pipe 4 at a middle inlet pipe 2. The middle inlet pipe 2 is arranged at the center of the top of a double-boat furnace tube 1 and aligned with the front part of the rear boat. Taking a graphite boat with 12 slots (the rear boat corresponds to slots 7 - 12) as an example, it is aligned with the front part of slot 7 of the rear boat of the graphite boat. When the double-boat furnace tube 1 is ventilated, gas enters through an inlet pipe 5 at the bottom of the furnace mouth of the double-boat furnace tube 1, and is exhausted through an outlet pipe 6 at the furnace tail. The gas flow direction is from the front boat to the rear boat of the graphite boat; at the same time, special gas and nitrogen are introduced into the double-boat furnace tube 1 through the middle inlet pipe 2, and the gas flows out through the nozzles of a jet nozzle 7 to supplement gas to the rear boat in the double-boat furnace tube 1.

[0043] When modifying the furnace door of the tube-type PECVD equipment, drill holes at the corresponding position in the double-boat furnace tube 1 and connect the middle inlet pipe 2. A T-shaped jet nozzle 7 is installed on the middle inlet pipe 2. The material of the used jet nozzle 7 is stainless steel, with the opening facing downwards; the connection between the middle inlet pipe 2 and the double-boat furnace tube 1 is sealed with a sealing ring.

[0044] The beneficial effects of the present utility model are as follows:

[0045] An apparatus for improving the gas uniformity of a tube-type PECVD provided in this embodiment adds a middle inlet pipe 2 in the furnace, making the gas uniformity of the rear boat better and optimizing the film layer uniformity of the rear boat; this apparatus is simple and operable for modifying the furnace door of the tube-type PECVD equipment, with low cost; it neither affects production capacity nor can significantly improve the coating uniformity of crystalline silicon cells, thus providing a greater space for further improving the efficiency of the cells.

[0046] As Figure 3 、 4 shown, in one embodiment, a mixing chamber 11 is arranged at the center inside the middle inlet pipe 2. A first inlet 12 and a second inlet 13 are respectively arranged at the top end and the side end of the middle inlet pipe 2. The first inlet 12 is connected to the special gas inlet pipe 3, and the second inlet 13 is connected to the nitrogen inlet pipe 4; a mixing outlet pipe 14 is arranged at the bottom end of the middle inlet pipe 2, and the mixing outlet pipe 14 is connected to the jet nozzle 7;

[0047] A rotating shaft 15 is connected to the top end of the mixing chamber 11, and a swirl vane 16 is rotatably connected to the rotating shaft 15. The swirl vane 16 is located above the second inlet 13;

[0048] A plurality of layers of baffle vanes 17 are uniformly connected inside the mixing outlet pipe 14. The baffle vanes 17 are arranged obliquely, and the inclination directions of the baffle vanes 17 in adjacent layers are opposite.

[0049] The working principle and beneficial effects of the above technical solution are as follows:

[0050] The special gas inlet pipe 3 and the nitrogen inlet pipe 4 converge inside the middle inlet pipe 2. A mixing chamber 11 is arranged inside the middle inlet pipe 2. An air flow including multiple gases is introduced through the top first air inlet 12. Under the action of the air flow, the swirl vanes 16 are driven to rotate around the rotating shaft 15, so as to mix the multiple special gases in the air flow evenly and improve the air flow uniformity of the special gas inlet. Nitrogen is introduced through the second air inlet 13. After the mixed special gas and nitrogen are mixed and flow into the mixed outlet pipe 14, when the mixed air flow flows in the mixed outlet pipe 14, the air flow direction is disrupted under the blocking of the baffle vanes 17, so that the special gas and nitrogen are mixed evenly again. After being mixed, the air flow flows into the jet nozzle 7 and is blown into the double-boat furnace tube 1. The opposite baffle vanes 17 can change the air flow direction multiple times, and the mixing effect of disrupting the air flow is better.

[0051] Through the above structural design, a mixing chamber 11 is arranged inside the middle inlet pipe 2 to mix the gases in the special gas inlet pipe 3 and the nitrogen inlet pipe 4 for the second time, improve the uniformity of multiple gases, enable the gases to be evenly distributed after being ejected, and further improve the battery coating quality.

[0052] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0053] Obviously, the above embodiments are only examples given for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A device for improving the uniformity of tubular PECVD gas, characterized in that: include: A middle air inlet pipe (2), the middle air inlet pipe (2) is connected to the top center of the double-boat furnace tube (1); two air inlet ends of the middle air inlet pipe (2) are respectively connected to the special gas air inlet pipe (3) and the nitrogen air inlet pipe (4), and the air outlet end of the middle air inlet pipe (2) faces the rear front of the graphite boat in the double-boat furnace tube (1).

2. The device for improving gas uniformity of tubular PECVD according to claim 1, characterized in that: A front graphite boat and a rear graphite boat are respectively arranged at the front and rear of the double-boat furnace tube (1).

3. The device for improving gas uniformity of tubular PECVD according to claim 2, characterized in that: The front graphite boat is arranged close to the furnace mouth of the double-boat furnace tube (1), and the rear graphite boat is arranged close to the furnace tail of the double-boat furnace tube (1). The air inlet pipe (5) of the double-boat furnace tube (1) is arranged at the bottom of the furnace mouth, and the air outlet pipe (6) is arranged at the furnace tail.

4. The device for improving gas uniformity of tubular PECVD according to claim 1, characterized in that: Any one or more combinations of silane, phosphine, hydrogen and laughing gas are introduced into the special gas inlet pipeline (3).

5. The device for improving gas uniformity of tubular PECVD according to claim 1, characterized in that: The air outlet end of the middle air inlet pipe (2) is connected with an air nozzle (7).

6. The device for improving gas uniformity of tubular PECVD according to claim 5, characterized in that: The air jet nozzle (7) is arranged as a T-shaped air jet nozzle, and a plurality of nozzles are evenly arranged at the bottom of the air jet nozzle (7).

7. The device for improving gas uniformity of tubular PECVD according to claim 6, characterized in that: The aperture of the nozzle is set to 3-5 mm.

8. The device for improving gas uniformity of tubular PECVD according to claim 1, characterized in that: A sealing ring is provided at the connection between the middle air inlet pipe (2) and the double-boat furnace tube (1).