Substrate diffusion device

Abstract

The application discloses a substrate diffusion device, comprising: a furnace body comprising a first end and a second end opposite to each other, the furnace body forming a furnace body cavity; the substrate placing area is arranged in the furnace body cavity; one end of the air inlet pipe is provided with a flaring part, the flaring part partially or completely extends into the furnace body cavity from the first end and points to the substrate placing area, and the cross section of the flaring part is gradually increased in the direction close to the substrate placing area. According to the substrate diffusion device, the diffusion performance of diffusion gas can be improved, and then the sheet resistance uniformity of the to-be-machined workpiece in the substrate placement area is improved.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to a substrate diffusion device. Background Art

[0002] The diffusion furnace equipment provides diffusion gas to the furnace chamber through the air inlet pipe. Since the temperature of the diffusion gas is significantly lower than the temperature inside the diffusion furnace and the cross-sectional area of ​​the air inlet pipe is small, the diffusion gas will quickly contact the silicon wafer at a large flow rate, causing the temperature of the silicon wafer near the air inlet to drop, resulting in high square resistance of the silicon wafer near the air inlet and low square resistance of the silicon wafer far from the air inlet, which in turn leads to uneven square resistance of the silicon wafers on the entire quartz boat. Utility Model Content

[0003] The present application provides a substrate diffusion device to solve the problem that the cross-sectional area of ​​the air inlet pipe in the diffusion furnace equipment is small, and the diffusion gas will quickly contact the silicon wafer at a large flow rate, causing the temperature of the silicon wafer near the air inlet to drop, resulting in high square resistance of the silicon wafer near the air inlet and low square resistance of the silicon wafer far from the air inlet, which in turn leads to uneven square resistance of the silicon wafers on the entire quartz boat.

[0004] In order to solve the above technical problems, the present application proposes a substrate diffusion device, comprising: a furnace body, comprising a first end and a second end opposite to each other, the furnace body forming a furnace body cavity; a substrate placement area, arranged in the furnace body cavity; an air inlet pipe, one end of which is provided with a flared portion, the flared portion partially or completely extends into the furnace body cavity from the first end and points to the substrate placement area, and the cross-section of the flared portion gradually increases in a direction approaching the substrate placement area.

[0005] The furnace cavity includes a main body cavity and an inlet cavity connected to the main body cavity. The inlet cavity is arranged at a position on the main body cavity corresponding to the first end, and the space in the inlet cavity is adapted to the expansion portion.

[0006] The cross section is any one of a circle, an ellipse and a polygon.

[0007] Wherein, the distance between an end of the substrate placement area close to the first end and the air outlet end of the expanded portion is greater than or equal to 100 mm and less than or equal to 500 mm.

[0008] The inner diameter of the end of the expanded portion away from the air intake pipe is greater than 4 mm and less than or equal to 480 mm.

[0009] The length of the expanded portion along the axial direction of the intake pipe is less than or equal to 500 mm.

[0010] The inner diameter of the air intake pipe is greater than or equal to 4 mm and less than or equal to 32 mm.

[0011] The outer diameter of the air intake pipe is greater than or equal to 8 mm and less than or equal to 40 mm.

[0012] Wherein, a heat-conducting structure is arranged in the expanded portion, and the heat-conducting structure is in heat-conducting contact with the side wall of the expanded portion.

[0013] Wherein, the heat conduction structure includes a plurality of airflow guide plates.

[0014] The beneficial effect of the present application is as follows: Different from the prior art, the present application provides a substrate diffusion device. The substrate diffusion device includes a furnace body, a substrate placement area and an air inlet pipe. The furnace body includes a first end and a second end opposite to each other. The furnace body forms a furnace body cavity. The substrate placement area is arranged in the furnace body cavity. A flared portion is arranged at one end of the air inlet pipe. The flared portion partially or completely extends into the furnace body cavity from the first end and points to the substrate placement area. The cross-section of the flared portion gradually increases in the direction close to the substrate placement area. The airflow velocity of the diffusion gas flowing out of the flared portion decreases, and the time for the diffusion gas to flow from the flared portion to the substrate placement area is increased. The diffusion gas has enough time to be heated to prevent cold air from overshooting. In addition, when the diffusion gas diffuses from the flared portion into the furnace body cavity, the diffusion gas has begun to diverge, the diffusion gas pressure increases, and a uniform gas field can be achieved after a short distance, thereby improving the diffusion gas divergence performance. Through the above method, the uniformity of the square resistance of the workpiece to be processed in the substrate placement area is improved, and the problem of high square resistance near the air inlet at the air inlet pipe, low square resistance at the end away from the air inlet, and uneven square resistance of the workpiece to be processed in the substrate placement area is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0016] Figure 1 It is a first partial schematic diagram of an embodiment of a substrate diffusion device of the present application;

[0017] Figure 2 It is a second partial schematic diagram of an embodiment of a substrate diffusion device of the present application.

[0018] Figure numbers: 10, substrate diffusion device; 1, furnace body; 1a, first end; 1b, second end; 11, furnace body cavity; 111, main body cavity; 12, inlet part; 121, inlet cavity; 2, substrate placement area; 3, air inlet pipe; 31, expansion part; 4, ferrule; 5, connecting piece. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0021] A substrate diffusion device provided by the utility model is described in detail below in conjunction with an embodiment.

[0022] See also Figure 1 , Figure 1 It is a first partial schematic diagram of an embodiment of a substrate diffusion device of the present application. The present application provides a substrate diffusion device 10. The substrate diffusion device 10 includes a furnace body 1, a substrate placement area 2, an air inlet pipe 3 and an exhaust pipe (not shown in the figure). The substrate placement area 2, the air inlet pipe 3 and the exhaust pipe are installed on the furnace body 1, the air inlet pipe 3 is passed through the diffusion gas for processing, and the exhaust pipe extracts the gas in the furnace body 1. The furnace body 1 includes a first end 1a and a second end 1b arranged opposite to each other. The furnace body 1 forms a furnace body cavity 11. The substrate placement area 2 is arranged in the furnace body cavity 11. The substrate placement area 2 can be detachably or fixedly connected to the furnace body cavity 11, or is only used as a virtually divided area range, and its specific setting method is not limited. A workpiece to be processed is placed in the substrate placement area 2 (not shown in the figure). The placement orientation and arrangement of the workpiece to be processed in the substrate placement area 2 are not limited and can be determined according to actual conditions. The workpiece to be processed can be a substrate. The substrate can be a silicon wafer, etc.

[0023] The air inlet pipe 3 is arranged at the first end 1a of the furnace body 1. The air inlet pipe 3 is used to provide diffusion gas to the furnace body cavity 11. A flared portion 31 is arranged at one end of the air inlet pipe 3. The air inlet pipe 3 and the flared portion 31 are connected. The flared portion 31 partially or completely extends from the first end 1a of the furnace body 1 into the furnace body cavity 11 near the first end 1a; at the same time, the flared portion 31 points to the substrate placement area 2. That is, the diffusion gas enters the first end 1a of the furnace body cavity 11 from the air inlet pipe 3 and the flared portion 31 in turn, and is blown toward the substrate placement area 2. The flared portion 31 can be integrally formed with the air inlet pipe 3, or can be used as a split mounting part.

[0024] For those skilled in the art, there is a certain relationship between the cross section, diffusion gas flow rate, and pressure. For example, the continuity equation for a one-dimensional steady flow is AρV=C. Among them, A is the cross section through which the fluid passes, ρ is the density, and V is the flow rate. From the above equation, it can be seen that the cross section is inversely proportional to the flow rate. The larger the cross section, the smaller the flow rate; the smaller the cross section, the greater the flow rate.

[0025] Bernoulli's equation is P+1 / 2ρV 2 +ρgh=C. Where P is pressure, V is flow velocity, ρ is density, h is height, g is acceleration due to gravity, and C is a constant. For the same gas at the same height, the pressure is inversely proportional to the flow velocity. The pressure is low where the flow velocity is high, and the pressure is high where the flow velocity is low. Therefore, when the cross section is small, the flow velocity of the diffused gas flowing out is high and the pressure of the diffused gas is low, while when the cross section is large, the flow velocity of the diffused gas flowing out is low and the pressure of the diffused gas is high.

[0026] It can be known from the continuity equation of one-dimensional steady flow and the Bernoulli equation that during the process of increasing the cross-sectional area of ​​the expanded portion 31, the outflowing diffusion gas velocity decreases and the diffusion gas pressure increases. That is, by setting the expanded portion 31 at one end of the air inlet pipe 3 and gradually increasing the cross-sectional area of ​​the expanded portion 31, the airflow velocity of the diffusion gas flowing out of the expanded portion 31 is reduced, and the time for the diffusion gas to travel from the expanded portion 31 to the substrate placement area 2 is increased, so that the diffusion gas has enough time to be heated to prevent cold air from overshooting. In addition, when the diffusion gas diffuses from the expanded portion 31 into the furnace cavity 11, the diffusion gas has begun to diverge, the diffusion gas pressure increases, and a uniform gas field can be achieved after a short distance, thereby improving the diffusion gas divergence performance. In the above manner, the problem of high square resistance near the air inlet of the air inlet pipe 3, low square resistance at the end away from the air inlet, and uneven square resistance of the workpiece to be processed in the substrate placement area 2 is solved.

[0027] The cross section of the expanded portion 31 is a cross section along a direction perpendicular to the axial direction of the intake pipe 3. The cross section gradually increases from the first end 1a to the second end 1b.

[0028] The above-mentioned flared portion 31 can be arranged in a variety of positions in the furnace body 1. The furnace body cavity 11 includes a main body cavity 111 and an inlet cavity 121. The main body cavity 111 and the inlet cavity 121 are arranged in communication, and the inlet cavity 121 is arranged at a position corresponding to the first end 1a on the main body cavity 111. In a specific embodiment, the flared portion 31 is located in the inlet cavity 121. Placing the flared portion 31 in the inlet cavity 121 can first increase the distance between the substrate placement area 2 and the air inlet pipe 3, thereby solving the problem of abnormal resistance and color difference at one end of the substrate placement area 2 away from the air inlet pipe 3 when the distance between the substrate placement area 2 and the air inlet pipe 3 is too short. Secondly, because the flared portion 31 is arranged to make the distance required for the diffused gas to reach a uniform gas field in the furnace body cavity 11 shorter, the placement position of the substrate placement area 2 can be changed, that is, the distance between the substrate placement area 2 and the flared portion 31 is shortened, which can not only increase the available space in the furnace body cavity 11 and increase the output of the workpiece to be processed, but also reduce energy consumption.

[0029] In some other specific embodiments, a portion of the flared portion 31 is located in the inlet cavity 121. Another portion of the flared portion 31 is located in the main cavity 111. The specific location of the flared portion 31 can be determined according to actual conditions and is not limited here. In one embodiment, a heat-conducting structure (not shown in the figure) is provided in the flared portion 31, and the heat-conducting structure is in heat transfer contact with the side wall of the flared portion 31 to be heated together with the flared portion 31. The heat-conducting structure can play a heat-conducting role. When the diffusion gas flows through the above-mentioned heat-conducting structure, the heat-conducting structure enables heat to be transferred to the diffusion gas, thereby preheating the diffusion gas. The heat-conducting structure can be any structure that can transfer heat to the diffusion gas, and its specific structure is not limited.

[0030] Among them, the heat conduction structure of one embodiment includes a plurality of airflow guide sheets (not shown in the figure). The airflow guide sheets are arranged in a sheet shape, which can reduce the resistance to the airflow and reduce local disturbances. At the same time, the side of the airflow guide sheet plays a certain guiding role on the nearby airflow, and can be used to finely adjust the gas flow section in the expansion part 31, such as appropriately guiding a part of the airflow at the center of the flow section to the edge of the flow section, so that the overall distribution of the airflow is accelerated to a uniform state.

[0031] In one embodiment, the cross section of the inlet portion 12 along the direction perpendicular to the axial direction of the air inlet pipe 3 is larger than the cross section of the flared portion 31 along the direction perpendicular to the axial direction of the air inlet pipe 3. The cross section of the inlet portion 12 along the direction perpendicular to the axial direction of the air inlet pipe 3 needs to satisfy any cross section of the flared portion 31 at least partially at the air inlet pipe 3 along the direction perpendicular to the axial direction of the air inlet pipe 3. In the above manner, it is convenient for the flared portion 31 to extend into the furnace cavity 11 through the inlet portion 12, thereby facilitating the removal and installation of the air inlet pipe 3 and the flared portion 31.

[0032] The cross section of the inlet portion 12 along the direction perpendicular to the axial direction of the intake pipe 3 changes with the cross section of the flared portion 31 along the direction perpendicular to the axial direction of the intake pipe 3. When the flared portion 31 is entirely located at the inlet portion 12, the cross section of the inlet portion 12 along the direction perpendicular to the axial direction of the intake pipe 3 is greater than the cross section of any flared portion 31 along the direction perpendicular to the intake pipe 3. When the flared portion 31 is partially located at the inlet portion 12, the cross section of the inlet portion 12 along the direction perpendicular to the axial direction of the intake pipe 3 is greater than the cross section of the flared portion 31 at the inlet portion 12 in the direction perpendicular to the axial direction of the intake pipe 3.

[0033] In one embodiment, the cross section is any one of a circular, elliptical, and polygonal shape. By limiting the above cross-sectional shape, the diffusion resistance of the diffused gas along its side wall can be reduced, and the diffusion gas divergence performance can be improved. Among them, the cross-sectional shape of the flared portion 31 along the axial direction perpendicular to the intake pipe 3 can be determined according to actual conditions. If the cross section is circular, the flared portion 31 is conical. Or, the cross section is elliptical. Or, the cross section is polygonal. Among them, the polygon can be a triangle, a quadrilateral, a pentagon, a hexagon, etc., which are not limited here. As in this embodiment, the cross section is circular. The circular cross section can keep the airflow uniformly divergent when it diffuses to the surroundings, while the flared portion 31 with a special shape such as an elliptical or polygonal cross section can differentially adjust the gas divergence in a specific direction, adapt to some special furnace cavity environments or the arrangement of the workpieces to be processed, and has stronger adaptability. When the flared portion 31 is used as a detachable mounting component, it can also be replaced according to actual production needs, so as to flexibly change the shape of the flared portion 31.

[0034] In one embodiment, the distance between the end of the substrate placement area 2 close to the first end 1a of the furnace body 1 and the gas outlet end of the expanded portion 31 is greater than or equal to 100 mm and less than or equal to 500 mm. By limiting the distance between the end of the substrate placement area 2 close to the first end 1a and the gas outlet end of the expanded portion 31, the distance between the substrate placement area 2 and the air inlet pipe 3 can be increased, thereby solving the problem that when the distance between the substrate placement area 2 and the air inlet pipe 3 is too short, the side resistance of the end of the substrate placement area 2 away from the air inlet pipe 3 is abnormal, and the end of the substrate placement area 2 away from the air inlet pipe 3 after diffusion has color difference. At the same time, by limiting the distance between the end of the expanded portion 31 away from the air inlet pipe 3 and the end of the substrate placement area 2 close to the first end 1a, the distance between the substrate placement area 2 and the expanded portion 31 can be shortened, which can not only increase the available space in the furnace cavity 11, increase the output of the workpiece to be processed, but also reduce energy consumption. The minimum distance of 100 mm is set to allow the gas to have a certain divergence stroke and ensure a certain distribution uniformity. The maximum distance of 500 mm is set to save the internal space of the furnace cavity 11. 500 mm is enough to allow the airflow to fully diverge and ensure consistent square resistance.

[0035] The distance between the end of the flared portion 31 away from the air inlet pipe 3 and the end of the substrate placement area 2 close to the first end 1a is defined as L1. L1 can be 100mm, 134mm, 153mm, 190mm, 206mm, 230mm, 290mm, 300mm, 371mm, 405mm, 430mm, 470mm, 500mm. Of course, L1 can also be other values, which are not limited here. Further, L1 can be greater than or equal to 100mm and less than or equal to 500mm.

[0036] See also Figure 2 , Figure 2 1 is a second partial schematic diagram of an embodiment of a substrate diffusion device of the present application. Figure 1 In one embodiment, the inner diameter of the end of the flared portion 31 away from the air inlet pipe 3 is greater than 4 mm and less than or equal to 480 mm. By limiting the inner diameter of the end of the flared portion 31 away from the air inlet pipe 3, the flared portion 31 is flared, the diffused gas is quickly dispersed, the diffused gas pressure is increased, and the gas field is quickly uniformed, thereby solving the problem of high square resistance near the air inlet of the air inlet pipe 3, low square resistance at the end away from the air inlet, and uneven square resistance of the workpiece to be processed in the substrate placement area 2. The minimum value of the inner diameter of the end of the flared portion 31 is 4 mm, which corresponds to the minimum inner diameter of the air inlet pipe 3. When the inner diameter is less than 4 mm, the gas supply is too small and it is difficult to meet the process requirements. The maximum value of the inner diameter of the end of the flared portion 31 is 480 mm. Considering the conventional size of the furnace cavity 11 of the existing diffusion furnace equipment, it will significantly affect the installation of the flared portion 31.

[0037] The inner diameter of the end of the expanded portion 31 away from the air intake pipe 3 is defined as L2. L2 can be 4mm, 11mm, 23mm, 54mm, 79mm, 103mm, 189mm, 243mm, 270mm, 298mm, 321mm, 357mm, 387mm, 401mm, 430mm and 480mm. Of course, L2 can also be other values, which are not limited here.

[0038] In one embodiment, the angle between the side wall of the expanded portion 31 and the axial direction of the air inlet pipe 3 is greater than 0 degrees and less than 90 degrees. By limiting the angle between the end of the expanded portion 31 close to the air inlet pipe 3 and the axial direction of the air inlet pipe 3, the expanded portion 31 is extended in an inclined shape, which can guide the diffusion gas to flow along the inclined side wall, facilitate the diffusion gas to diverge, and thus solve the problem that the square resistance near the air inlet of the air inlet pipe 3 is high and the square resistance at the end far away from the air inlet is low, and the square resistance of the workpiece to be processed in the substrate placement area 2 is uneven. In addition, the angle between the side wall of the expanded portion 31 and the axial direction of the air inlet pipe 3 can limit the air flow rate of the diffusion gas flowing out of the expanded portion 31. When the angle between the side wall of the expanded portion 31 and the axial direction of the air inlet pipe 3 increases, the cross section at the same position increases, and the diffusion gas flow rate decreases. The angle between the side wall of the expanded portion 31 and the axial direction of the air inlet pipe 3 needs to be determined according to the size of the furnace cavity 11 and the size of the spacing between the substrate placement area 2 and the end of the expanded portion 31 for the gas to diverge.

[0039] The angle between the end of the flared portion 31 close to the intake pipe 3 and the axial direction of the intake pipe 3 is defined as α. α can be 1 degree, 9 degrees, 13 degrees, 24 degrees, 27 degrees, 33 degrees, 37 degrees, 46 degrees, 49 degrees, 54 degrees, 59 degrees, 67 degrees, 75 degrees, 79 degrees, 84 degrees, 89 degrees. Of course, α can also be other values, which are not limited here.

[0040] Of course, in actual practice, the angle between the end of the expanded portion 31 close to the intake pipe 3 and the axial direction of the intake pipe 3 can be equal to 90 degrees. That is, one side wall of the expanded portion 31 is perpendicular to the outer side wall of the intake pipe 3, and the flow velocity of the diffused gas flowing out of the expanded portion 31 is rapidly reduced, so that the gas field is quickly homogenized.

[0041] In one embodiment, the dimension of the expanded portion 31 along the axial direction of the air inlet pipe 3 is less than or equal to 500 mm. By limiting the dimension of the expanded portion 31 along the axial direction of the air inlet pipe 3, the diffusion gas can be guided to diverge, the pressure of the diffusion gas can be increased, and the gas field can be uniformized, thereby solving the problem that the square resistance near the air inlet of the air inlet pipe 3 is high, the square resistance of the end of the air inlet pipe 3 away from the air inlet is low, and the square resistance of the workpiece to be processed in the substrate placement area 2 is uneven. The function of the expanded portion 31 is mainly to constrain and guide the divergence path of the gas during its divergence. After being constrained to a certain extent, the gas has been evenly diffused, and the furnace cavity 11 can be evenly filled without further constraint and guidance. Therefore, the dimension of the expanded portion 31 along the axial direction of the air inlet pipe 3 is limited, that is, the length is less than or equal to 500 mm.

[0042] The dimension of the side wall of the expanded portion 31 along the axial direction of the intake pipe 3 is defined as L3. L3 can be 1mm, 21mm, 78mm, 101mm, 171mm, 210mm, 267mm, 301mm, 324mm, 387mm, 401mm, 454mm, 500mm. Of course, L3 can also be other values, which are not limited here.

[0043] In one embodiment, the inner diameter of the air inlet pipe 3 is greater than or equal to 4 mm and less than or equal to 32 mm. By limiting the inner diameter of the air inlet pipe 3, the diffusion gas flow rate can be increased, so that more diffusion gas can enter the furnace cavity 11. The inner diameter of the air inlet pipe 3 is defined as L4. L4 can be 4mm, 9mm, 13mm, 18mm, 21mm, 26mm, 32mm. Of course, L4 can also be other values, which are not limited here. In the actual process, a certain supply speed needs to be reached from the air inlet pipe 3 into the furnace cavity 11, and the air flow cannot be too fast, so as not to affect the uniform divergence process of the gas after leaving the air inlet pipe 3. Therefore, the inner diameter of the air inlet pipe 3 is greater than or equal to 4mm to ensure that the gas obtains a suitable flow rate and flow.

[0044] In one embodiment, the outer diameter of the air inlet pipe 3 is greater than or equal to 8 mm and less than or equal to 40 mm. By limiting the outer diameter of the air inlet pipe 3, the diffusion gas flow rate can be increased, so that more diffusion gas enters the furnace cavity 11. The outer diameter of the air inlet pipe 3 is defined as L5. L5 can be 8 mm, 10 mm, 13 mm, 18 mm, 21 mm, 26 mm, 30 mm, 35 mm, or 40 mm. Of course, L5 can also be other values, which are not limited here.

[0045] The inner diameter of the air inlet pipe 3 and the outer diameter of the air inlet pipe 3 change synchronously, which can ensure that the wall thickness of the air inlet pipe 3 is at a stable value. Of course, in the actual process, the inner diameter of the air inlet pipe 3 and the outer diameter of the air inlet pipe 3 do not change synchronously, such as the outer diameter of the air inlet pipe 3 does not change, and the inner diameter of the air inlet pipe 3 is set in a flared shape at one end close to the furnace cavity 11. That is, the inner diameter of the air inlet pipe 3 and the outer diameter of the air inlet pipe 3 can change according to actual conditions, and are not limited here. The wall of the air inlet pipe 3 has a certain wall thickness, such as greater than 4mm, which can ensure that the air inlet pipe 3 maintains its own structural stability at the process temperature and avoids the air inlet pipe 3 from being deformed due to long-term heat and having a negative impact on the process effect.

[0046] The substrate diffusion device 10 further includes a connector 5. The air inlet pipe 3 is provided with a ferrule 4 and an inlet portion 12. The connector 5 is fixed to the outer periphery of the inlet portion 12 and the outer periphery of the ferrule 4, and is used to lock the air inlet pipe 3 to the inlet portion 12. The connector 5 can be a clamp, a hoop, etc., which is not limited here.

[0047] In one embodiment, the substrate diffusion device 10 takes in air through the middle of the furnace tail, and the center position of the air intake pipe 3 is higher or slightly higher than the center position of the workpiece to be processed in the substrate placement area 2. In this way, it is easier for the diffusion gas to enter the workpiece to be processed, thereby improving the heating efficiency of the workpiece to be processed. Of course, in other embodiments, the height of the center position of the air intake pipe 3 can also be lower than the center position of the workpiece to be processed in the substrate placement area 2, which is not limited here.

[0048] Compared with the prior art, the substrate diffusion device includes a furnace body, a substrate placement area and an air inlet pipe. The furnace body includes a first end and a second end opposite to each other. The furnace body is formed with a furnace body cavity. The substrate placement area is arranged in the furnace body cavity. A flared portion is arranged at one end of the air inlet pipe. The flared portion partially or completely extends into the furnace body cavity from the first end and points to the substrate placement area. The cross section of the flared portion gradually increases in the direction close to the substrate placement area. The air flow velocity of the diffusion gas flowing out of the flared portion decreases, and the time for the diffusion gas to flow from the flared portion to the substrate placement area is increased. The diffusion gas has enough time to be heated to prevent cold air from overshooting. In addition, when the diffusion gas diffuses from the flared portion into the furnace body cavity, the diffusion gas has begun to diverge, the diffusion gas pressure increases, and a uniform gas field can be achieved after a short distance, thereby improving the diffusion gas divergence performance. Through the above-mentioned method, the uniformity of the square resistance of the workpiece to be processed in the substrate placement area is improved, and the problem of high square resistance near the air inlet at the air inlet pipe, low square resistance at the end away from the air inlet, and uneven square resistance of the workpiece to be processed in the substrate placement area is solved.

[0049] The terms "first", "second", "third" in this application are only used for descriptive purposes and cannot be understood as indicating the quantity of the indicated technical features. Thus, the features defined as "first", "second", "third" can expressly or implicitly include at least one of these features. In the embodiments of the present application, all directional indications (such as up, down, left, right, front, back ...) are only used to explain the relative positional relationship, motion conditions, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly. In addition, the terms "include" and "have" and any of their variations are intended to cover non-exclusive inclusions. The process, method, system, product or equipment such as including a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or equipment.

[0050] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A substrate diffusion device, characterized in that: include: A furnace body, comprising a first end and a second end opposite to each other, the furnace body forming a furnace body cavity; A substrate placement area is arranged in the furnace cavity; The air inlet pipe has a flared portion at one end, the flared portion partially or completely extends into the furnace cavity from the first end and points to the substrate placement area, and the cross-section of the flared portion gradually increases in a direction approaching the substrate placement area.

2. The substrate diffusion device according to claim 1, characterized in that: The furnace cavity comprises a main body cavity and an inlet cavity communicated with the main body cavity. The inlet cavity is arranged at a position on the main body cavity corresponding to the first end. The space in the inlet cavity is adapted to the flared portion.

3. The substrate diffusion device according to claim 1, characterized in that: The cross section is any one of a circle, an ellipse and a polygon.

4. The substrate diffusion device according to claim 1, characterized in that: The distance between the end of the substrate placement area close to the first end and the air outlet end of the flared portion is greater than or equal to 100 mm and less than or equal to 500 mm.

5. The substrate diffusion device according to claim 1, characterized in that: The inner diameter of the end of the flared portion away from the air intake pipe is greater than 4 mm and less than or equal to 480 mm.

6. The substrate diffusion device according to claim 1, characterized in that: The length of the expanded portion along the axial direction of the intake pipe is less than or equal to 500 mm.

7. The substrate diffusion device according to any one of claims 1 to 6, characterized in that: The inner diameter of the air intake pipe is greater than or equal to 4 mm and less than or equal to 32 mm.

8. The substrate diffusion device according to claim 7, characterized in that: The outer diameter of the air intake pipe is greater than or equal to 8 mm and less than or equal to 40 mm.

9. The substrate diffusion device according to any one of claims 1 to 6, characterized in that: A heat-conducting structure is disposed in the flared portion, and the heat-conducting structure is in heat-transfer contact with the side wall of the flared portion.

10. The substrate diffusion device according to claim 9, characterized in that: The heat conduction structure includes a plurality of airflow guiding fins.

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