Wet oxygen furnace

Abstract

The utility model provides a wet oxygen furnace, and aims to solve the technical problem that the yield and quality of silicon wafer oxidation films are affected due to poor temperature uniformity and poor production continuity of the conventional oxidation furnace. The furnace comprises a furnace body, a thermal control unit and a transmission unit. The furnace body is used for oxidation of silicon wafers, and a transmission channel penetrates through the furnace body. The transmission channel is divided into a plurality of temperature control areas which are communicated with one another. And the furnace body is provided with a nitrogen pipeline, an oxygen pipeline and a water vapor pipeline leading to the transmission channel. The water vapor pipeline leads to the temperature control area close to the center of the transmission channel. The thermal control unit is matched with the temperature control area and installed on the furnace body. The transmission unit is externally connected with a driving device and used for transmitting the silicon wafers, and a conveying roller set arranged on the transmission unit penetrates through the transmission channel in the direction perpendicular to the transmission direction and is installed on the side wall of the furnace body. Through the cooperation of the thermal control unit and the transmission unit, silicon wafers at any position of the conveying roller group can be oxidized at a constant temperature, so that the process continuity is ensured, and the yield and quality of silicon wafer oxidation films are improved.

Description

Technical Field

[0001] This application relates to the field of wet oxidation of silicon wafers, and more particularly to a wet oxidation furnace. Background Technology

[0002] In the production of crystalline silicon solar cells, considering factors such as production costs and market demand, thinning of the silicon substrate has become an inevitable trend. However, this leads to severe surface recombination, significantly impacting the cell's conversion efficiency. Therefore, in the pursuit of high-efficiency solar cells, engineers have begun researching various passivation technologies for cell surfaces, such as SiNx thin-film passivation, SiO2 thin-film passivation, and Al2O3 thin-film passivation.

[0003] SiO2 thin film passivation technology generally includes dry oxidation and wet oxidation. Due to production demands for faster film formation speeds and higher efficiency, companies typically prioritize wet oxidation to prepare oxide films on silicon wafers. This involves placing the silicon wafer in a high-temperature oxidation furnace, where a SiO2 thin film grows on the wafer surface in a reaction atmosphere containing oxygen and a certain amount of water vapor, achieving passivation. However, technicians have discovered the following problems with traditional oxidation furnaces in production:

[0004] (1) The temperature uniformity inside the furnace is very poor, which makes the quality of the oxide film generated by silicon wafers placed in different positions inside the furnace vary greatly. Even if it is found that the temperature difference in a certain position inside the furnace is too large and is particularly unfavorable for the generation of high-quality silicon wafer oxide film, the temperature control accuracy inside the furnace cannot be guaranteed due to the low degree of automation of the furnace temperature control. Therefore, the silicon wafers can only be avoided as much as possible in this position, which leads to the waste of furnace space and reduces the output of high-quality silicon wafer thin film.

[0005] (2) Usually, after a batch of silicon wafers is oxidized, the temperature inside the furnace needs to be significantly reduced so that the operators can take out the silicon wafers and put in new silicon wafers. This lengthens the process time and reduces production efficiency. At the same time, it can easily lead to an unstable reaction atmosphere inside the furnace, which is not conducive to the production of high-quality silicon wafer oxidized films. Utility Model Content

[0006] This invention provides a wet oxygen furnace to solve the problems mentioned in the background art.

[0007] A humidified oxygen furnace, characterized in that: the humidified oxygen furnace comprises:

[0008] The furnace body, used for the oxidation of silicon wafers, has a transmission channel running through it; the transmission channel is divided into multiple interconnected temperature control zones; the furnace body is equipped with nitrogen pipes, oxygen pipes, and water vapor pipes leading to the transmission channel; the water vapor pipes lead to the temperature control zone near the center of the transmission channel;

[0009] A thermal control unit is installed in the furnace body to match the temperature control zone, for independent temperature control of the temperature control zone;

[0010] The transmission unit is equipped with an external drive device for transmitting silicon wafers. Its conveying roller group runs through the transmission channel perpendicular to the transmission direction and is installed on the side wall of the furnace body.

[0011] Furthermore, the nitrogen pipe, the oxygen pipe, and the water vapor pipe are all installed through the furnace sidewall perpendicular to the transmission direction; each of the pipes is provided with a group of through holes.

[0012] Furthermore, the transmission channel includes a left temperature control zone, a middle temperature control zone, and a right temperature control zone; the three temperature control zones are interconnected; oxygen pipelines and nitrogen pipelines are respectively provided in the left temperature control zone and the right temperature control zone; oxygen pipelines and water vapor pipelines are provided in the middle temperature control zone.

[0013] Furthermore, the thermal control unit includes a thermocouple, a controller, and a heating lamp assembly;

[0014] The thermocouple is installed through the furnace sidewall in the vertical transmission direction and located below the conveying roller assembly for temperature detection within the transmission channel.

[0015] The controller is installed in the furnace body and connected to the output terminal of the thermocouple;

[0016] The heating lamp assembly is installed through the furnace sidewall in the vertical transmission direction and is located above the conveying roller assembly; the input end of the heating lamp assembly is connected to the controller.

[0017] Furthermore, each conveying roller is connected to a first magnetic wheel at one end;

[0018] The transmission unit also includes a power roller assembly and a mounting frame;

[0019] The power roller assembly includes two power rollers; the two power rollers are respectively arranged opposite each other on both sides of the furnace body; each power roller is arranged parallel to the transmission direction and located below the first magnetic wheel; a second magnetic wheel matching the first magnetic wheel is sleeved on the outside of the power roller;

[0020] The mounting frame includes two sets; the two sets of mounting frames are matched with the power roller assembly and are disposed on both sides of the furnace body for mounting the power roller assembly and the conveyor roller assembly.

[0021] Furthermore, each of the mounting brackets includes a first extension and a second extension for mounting the conveyor roller; the first extension is connected to the end of the mounting bracket near the silicon wafer feed point; and the second extension is connected to the end of the mounting bracket near the silicon wafer discharge point.

[0022] Furthermore, each of the power rollers is provided with extension rollers at both ends along the transmission direction for mounting the second magnetic wheel.

[0023] Furthermore, the output end of the water vapor pipeline is connected to a water bath bottle, through which deionized water is supplied into the water vapor pipeline.

[0024] Furthermore, the wet oxygen furnace also includes a support frame and a protective plate;

[0025] The bracket is divided into a first installation space and a second installation space from top to bottom by a partition; a fan device is installed in the second installation space; the furnace body and the mounting bracket are installed on the top of the partition;

[0026] The protective plate is installed on the bracket; the protective plate is provided with a plurality of heat dissipation holes.

[0027] Furthermore, heat exhaust devices are connected to both sides of the furnace body along the transmission direction; the heat exhaust devices have an exhaust channel running from bottom to top; the air inlet of the exhaust channel is located near the top of the transmission channel.

[0028] Compared with the prior art, the beneficial effects of this utility model are:

[0029] By combining the thermal control unit and the transmission unit, silicon wafers at any position on the conveyor roller can be oxidized at a constant temperature, ensuring process continuity while improving the yield and quality of silicon wafer oxide films. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a front view (excluding the protective plate) of a wet oxygen furnace according to Embodiment 3 of this application.

[0032] Figure 2 This is a rear front view of a wet oxygen furnace equipped with a thermal control unit and a transmission unit, according to an embodiment of this application.

[0033] Figure 3 This is a side view of a wet oxygen furnace according to Embodiment 3 of this application.

[0034] Figure label:

[0035] 1. Furnace body; 11. Left temperature control zone; 12. Middle temperature control zone; 13. Right temperature control zone; 14. Nitrogen pipeline; 15. Oxygen pipeline; 16. Water vapor pipeline; 1a. Transmission channel;

[0036] 21. Heating lamp assembly; 22. Thermocouple;

[0037] 31. Conveyor roller; 310. First magnetic wheel; 32. Power roller; 320. Second magnetic wheel; 321. Extension roller; 33. Mounting frame; 331. Right extension; 332. Left extension; 34. Support base; 35. Drive unit;

[0038] 4. Protective plate; 41. Heat dissipation hole assembly;

[0039] 5. Bracket; 51. Partition; 52a. First installation space; 52b. Second installation space;

[0040] 6. Heat dissipation device; 61. Exhaust passage;

[0041] 7. Electrical control box. Detailed Implementation

[0042] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0043] In the description of this utility model, it should be understood that the terms "center", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this utility model and to simplify the description, and are not intended to 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 limitations on this utility model.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0045] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] The following disclosure provides many different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals may be repeated in different examples; this repetition is for simplification and clarity and does not in itself indicate any relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0048] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0049] This utility model embodiment provides a humidification furnace; please refer to... Figures 1-3 The wet oxygen furnace includes a furnace body 1, a thermal control unit, and a transmission unit.

[0050] Specifically,

[0051] Furnace 1, used for silicon wafer oxidation, has a transfer channel 1a running through it from left to right. To maintain a constant temperature in the transfer channel 1a, it is divided into multiple temperature control zones. These zones are interconnected. Nitrogen pipes 14, oxygen pipes 15, and water vapor pipes 16 are installed through the side walls of furnace 1 from front to back, and each pipe has a set of through holes to facilitate the transfer of its corresponding material into the transfer channel 1a. The water vapor pipe 16 is located in the temperature control zone near the center of the transfer channel 1a. The output end of the water vapor pipe 16 can be connected to a water bath bottle, which supplies deionized water into the water vapor pipe 16. Preferably, the transfer channel 1a includes three temperature control zones: a left temperature control zone 11, a middle temperature control zone 12, and a right temperature control zone 13. Oxygen pipes 15 and nitrogen pipes 14 are respectively provided in the left and right temperature control zones 11 and 13, while oxygen pipes 15 and water vapor pipes 16 are provided in the middle temperature control zone 12.

[0052] A thermal control unit is matched and located in the temperature control zone. That is, when the temperature of any temperature control zone deviates from the preset temperature of the furnace body, the corresponding thermal control unit adjusts the temperature of that temperature control zone, thereby achieving independent and precise temperature control of the temperature control zone. Each thermal control unit includes a thermocouple 22, a controller, and a heating lamp assembly 21.

[0053] A thermocouple 22 is installed through the furnace body 1 along its front-to-back direction for temperature detection within transmission channel 1a. A controller is installed on the side wall of the furnace body 1 and connected to the output terminal of the thermocouple 22. A heating lamp assembly 21 is installed through the furnace body 1 along its front-to-back direction and positioned above the thermocouple 22. The input terminal of the heating lamp assembly 21 is connected to the output terminal of the controller. Infrared lamps can be used for this heating.

[0054] Taking the temperature deviation of the left temperature control zone 11 from the preset temperature range of the furnace body as an example: when the temperature of the left cavity 11 is lower than the preset temperature of the furnace body, the thermocouple 22 detects this and outputs a signal to the controller, which then processes and controls the power of the heating lamp group 21 to increase; conversely, the controller processes and controls the power of the heating lamp group 21 to decrease. The temperature adjustment of the other temperature control zones follows the same principle as the left temperature control zone 11, thereby enabling the transmission channel 1a to automatically maintain the preset temperature range and improving the temperature control accuracy. Therefore, there is no need to consider the placement position of the silicon wafers in the furnace body 1, which increases the utilization rate of the furnace space and improves the production capacity.

[0055] The transmission unit includes a conveyor roller assembly, a power roller assembly, and a mounting frame 33. The conveyor roller assembly runs through the furnace body 1 along its front-to-back direction and is positioned between the thermocouple 22 and the heating lamp assembly 21. Each conveyor roller 31 has a first magnetic wheel 310 connected to one end. The power roller assembly includes two power rollers 32, positioned at the front and rear of the furnace body 1, respectively. Each power roller 32 is parallel to the left-to-right direction of the furnace body 1 and located below the first magnetic wheel 310. A second magnetic wheel 320 matching the first magnetic wheel 310 is fitted onto the outer side of each power roller 32. That is, each second magnetic wheel 320 is positioned directly below each first magnetic wheel 310 with a gap. Two mounting frames 33 are provided, one at the front and one at the rear of the furnace body 1, respectively, allowing the conveyor roller assembly and the power roller assembly to be mounted on the mounting frames 33. Each power roller 32 is connected to the mounting frame 33 via a support seat 34 sleeved on its outer side, thereby realizing the installation of the power roller 32 at the mounting frame 33.

[0056] A drive device 35 is connected to a power roller 32. The drive device 35 drives the rotation of the power roller 32. Under the magnetic interaction of the second magnetic wheel 320 and the first magnetic wheel 310, the conveying roller 31 is driven to rotate, so that the silicon wafer is conveyed from one end of the transmission channel 1a to the other end, which greatly increases the continuity of the process and improves the production capacity.

[0057] Based on the above embodiments, the operation of this application is as follows:

[0058] Multiple silicon wafers are placed at the feed inlet of transport channel 1a. The wafers are then fed into transport channel 1a via a transport unit. The wafers first pass through a temperature-controlled zone group equipped with oxygen pipe 15 and nitrogen pipe 14, then through another temperature-controlled zone group equipped with oxygen pipe 15 and water vapor pipe 16, and subsequently through the temperature-controlled zone group connected to oxygen pipe 15 and nitrogen pipe 14 before finally exiting transport channel 1a. The temperature of each temperature-controlled zone is independently controlled by its corresponding thermal control unit, ensuring that the temperature of each zone remains within the preset temperature range of the furnace body.

[0059] Based on this embodiment, the advantages of this application are:

[0060] Through the combined action of the thermal control unit and the transmission unit, silicon wafers at any position on the conveyor roller group can be oxidized at a constant temperature, ensuring process continuity while improving the yield and quality of silicon wafer oxide films.

[0061] Example 2

[0062] Based on Example 1, please refer to Figure 2To facilitate the loading / unloading of silicon wafers, each mounting frame 33 also includes a left extension 332 and a right extension 331 for mounting the conveyor rollers 31. The left extension 332 is connected to the left end of the mounting frame 33, and the right extension 331 is connected to the right end of the mounting frame 33. By continuing to install the conveyor rollers 31 at the left extension 332 and the right extension 331 to extend the conveyor roller assembly, the convenience of loading silicon wafers is increased. At the same time, each power roller 32 has extension rollers 321 at both ends along the left-right direction of the furnace body for mounting the second magnetic wheels 320, so that each second magnetic wheel 320 is spaced directly below each first magnetic wheel 310.

[0063] Example 3

[0064] Based on Example 1, please refer to Figure 1 and Figure 3 To enhance heat dissipation from the furnace body 1, the wet oxygen furnace also includes a support frame 5 and a protective plate 4. The support frame 5 is divided into a first installation space 52a and a second installation space 52b from top to bottom by a partition 51. The second installation space 52b houses the electrical control box 7 and a fan device. The furnace body 1 and the mounting bracket 33 are mounted on top of the partition 51, and the fan device dissipates heat from the furnace body 1. Heat dissipation devices 6 are connected to the left and right ends of the furnace body 1, respectively. These devices have an exhaust channel 61 extending from bottom to top, with the inlet of the exhaust channel 61 positioned above the transmission channel 1a to facilitate the discharge of hot air from the transmission channel 1a out of the furnace body 1. The protective plate 4 is mounted on the support frame 5, and a group of heat dissipation holes 41 are formed in the protective plate 4.

Claims

1. A wet oxygen furnace characterized by: The wet oxidation furnace comprises: a furnace body for oxidizing silicon wafer, through which a transmission channel is formed; the transmission channel is divided into multiple temperature control zones which are communicated with each other; the furnace body is provided with a nitrogen gas pipeline, an oxygen gas pipeline and a water vapor pipeline which are connected to the transmission channel; the water vapor pipeline is connected to the temperature control zone near the center of the transmission channel; a heat control unit which is installed on the furnace body in correspondence with the temperature control zones and is used for independent temperature control of the temperature control zones; a transmission unit which is externally connected with a driving device and is used for transmission of the silicon wafer, and is provided with a conveying roller set which is arranged along a direction perpendicular to the transmission direction and is installed on the side wall of the furnace body.

2. A wet air oven according to claim 1, wherein: The nitrogen gas pipeline, the oxygen gas pipeline and the water vapor pipeline are all arranged along a direction perpendicular to the transmission direction and are installed on the side wall of the furnace body; each of the pipelines is provided with a group of through holes.

3. The wet air oven of claim 1, wherein: The transmission channel comprises a left temperature control zone, a middle temperature control zone and a right temperature control zone; the three temperature control zones are communicated with each other; the left temperature control zone and the right temperature control zone are respectively provided with an oxygen gas pipeline and a nitrogen gas pipeline; the middle temperature control zone is provided with an oxygen gas pipeline and a water vapor pipeline.

4. The wet oxidation furnace according to any one of claims 1-3, characterized in that: the heat control unit comprises a thermocouple, a controller and a group of heating lamp tubes; the thermocouple is installed on the side wall of the furnace body in a direction perpendicular to the transmission direction and is arranged below the conveying roller set and is used for temperature detection in the transmission channel; the controller is installed on the furnace body and is connected with the output end of the thermocouple; the group of heating lamp tubes is installed on the side wall of the furnace body in a direction perpendicular to the transmission direction and is arranged above the conveying roller set; the input end of the group of heating lamp tubes is connected with the controller.

5. The wet oxidation furnace according to claim 4, characterized in that: one end of each conveying roller is connected with a first magnetic wheel; the transmission unit further comprises a power roller set and a mounting bracket; the power roller set comprises two power rollers; the two power rollers are arranged on the two sides of the furnace body respectively; each power roller is arranged in parallel to the transmission direction and is located below the first magnetic wheel; the outer side of the power roller is sleeved with a second magnetic wheel which is matched with the first magnetic wheel; the mounting bracket comprises two groups; the two groups of mounting brackets are arranged on the two sides of the furnace body in correspondence with the power roller set and are used for mounting the power roller set and the conveying roller set.

6. The wet oxidation furnace according to claim 5, characterized in that: each mounting bracket comprises a first extension part and a second extension part and is used for mounting the conveying roller; the first extension part is connected to the end of the mounting bracket near the inlet of the silicon wafer; the second extension part is connected to the end of the mounting bracket near the outlet of the silicon wafer.

7. A wet air oven according to claim 6, wherein: each power roller is provided with an extension roller at each end along the transmission direction, which is used for sleeving the second magnetic wheel.

8. A wet air oven as claimed in claim 1, wherein: the output end of the water vapor pipeline is connected with a water bath bottle, and deionized water is supplied into the water vapor pipeline from the water bath bottle.

9. The wet oxidation furnace according to claim 5, characterized in that: the wet oxidation furnace further comprises a support and a protective plate; the support is divided into a first mounting space and a second mounting space by a partition plate from top to bottom; the second mounting space is provided with a fan device; the top of the partition plate is provided with the furnace body and the mounting bracket. The protection plate is installed on the support, and is provided with a plurality of heat dissipation hole groups.

10. The wet oxygen furnace according to claim 9, characterized in that: Heat exhaust devices are connected to both sides of the furnace body along the transmission direction; The heat exhaust devices are penetrated by exhaust passages from bottom to top, and the gas inlets of the exhaust passages are arranged close to the top of the transmission passage.

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