Heating block with uniform temperature

Abstract

The invention relates to the technical field of semiconductor manufacturing equipment, and discloses a uniform-temperature heating block which comprises a heating body, the bottom of the heating body is connected with a supporting body through a cover body, and a thermal insulation space is formed between the heating body and the cover body. The heat insulation space can be used for heat insulation, the direct contact area of the heating body and the cover body is reduced to the maximum degree, the supporting body is connected with the cover body, indirect heat transfer is conducted between the heating body and the supporting body, heat of the heating body can be transferred to the supporting body to the minimum degree, the heat loss amount of the heating body can be reduced, and the service life of the heating body is prolonged. And the temperature uniformity of the heating body is improved, so that the uniformity of the thickness of a film deposited in the chemical vapor deposition process is relatively good, and the yield and the quality reliability of a semiconductor device are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing equipment, and more specifically, to a heating block with uniform temperature. Background Art

[0002] The semiconductor thin film process is a process of depositing materials on the surface of a wafer by physical or chemical means; the chemical vapor deposition process of a semiconductor wafer is carried out in a vacuum chamber, and various metal heaters including aluminum and ceramic heaters are usually used as heating elements for the semiconductor wafer.

[0003] As Figure 1 shown, the heating element in the prior art includes a heating body 1 and a support rod 10, and the temperature of the heating body 1 during operation is generally about 200°C to 450°C; as Figure 2 shown, when used in a vacuum chamber 11, the end of the support rod 10 and the bottom of the vacuum chamber 11 are sealed by an O-ring 12, and in order to prevent the O-ring 12 from being damaged due to the heat generated by the heating body 1 during operation, a cooling channel 13 is provided outside the vacuum chamber 11, and cooling is carried out through the cooling medium in the cooling channel 13;

[0004] When the temperature of the heating body 1 is 400°C, the temperature of the connection part between the end of the support rod 10 and the O-ring 12 is affected by the cooling medium and is about 50°C, and the temperature gradient difference is very large, which will cause an increase in heat loss at the central part of the heating body 1 connected to the support rod 10, resulting in poor temperature uniformity of the heating body 1; this is because the heating body 1 used in the chemical vapor deposition process usually uses aluminum with excellent thermal conductivity as its material, and the heating body 1 and the support rod 10 are directly welded together, so the heat at the central part of the heating body 1 will be dissipated through the support rod 10, resulting in a decrease in the temperature of the central part of the heating body 1;

[0005] When the temperature of the central part of the heating body 1 is too low, the thickness of the film deposited in the chemical vapor deposition process will also decrease accordingly, resulting in a decrease in the thickness of the central part of the semiconductor wafer, thereby affecting the yield and quality reliability of semiconductor devices.

[0006] Therefore, it is necessary to propose a heating block with uniform temperature to at least partially solve the problems existing in the prior art. Summary of the Invention

[0007] A series of simplified concepts are introduced in the summary of the invention part, which will be further detailed in the specific implementation part. The summary of the invention part of the present invention 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 at least partially solve the above problems, the present invention provides a heating block with uniform temperature, including: a heating body, the bottom of which is connected to a support body through a cover body, and a heat insulation space is formed between the heating body and the cover body.

[0009] Preferably, an annular recessed area is formed on the outer periphery of the inner bottom surface of the cover body, and a neck is formed on the side wall of the cover body near the annular recessed area.

[0010] Preferably, the thickness of the neck is 3 mm to 10 mm.

[0011] Preferably, the thickness of the neck is 5 mm.

[0012] Preferably, a heating element is arranged in the heating body, and the density of the heating element arranged at the edge part of the heating body is greater than the density of the heating element arranged at the central part of the heating body.

[0013] Preferably, the support body includes: an inner rod body connected to the cover body, an outer rod body is arranged outside the inner rod body, and a contact ring is arranged outside the outer rod body.

[0014] Preferably, a separation gap is left between the top surface of the outer rod body and the bottom surface of the cover body, and a heat insulation area is arranged at the upper part between the inner rod body and the outer rod body, and the heat insulation area is communicated with the separation gap.

[0015] Preferably, a communication hole is arranged on the cover body.

[0016] Preferably, an inner ring groove is arranged on the inner ring wall of the outer rod body, and a heat insulation area is formed between the inner ring groove and the outer ring wall of the inner rod body;

[0017] Or, an outer ring groove is arranged on the outer ring wall of the inner rod body, and a heat insulation area is formed between the outer ring groove and the inner ring wall of the outer rod body.

[0018] Preferably, the heat transfer path between the heating body and the support body is: the heating body, the cover body, the inner rod body, the outer rod body and the contact ring.

[0019] Compared with the prior art, the present invention at least includes the following beneficial effects:

[0020] The heating block with uniform temperature of the present invention can use the heat insulation space for heat insulation, maximize the reduction of the direct contact area between the heating body and the cover body, use the connection between the support body and the cover body to enable indirect heat transfer between the heating body and the support body, so that the heat of the heating body can be transferred to the support body with the least amount, reduce the heat loss of the heating body, improve the uniformity of the temperature of the heating body, so that the thickness uniformity of the deposited film in the chemical vapor deposition process is better, and improve the yield and quality reliability of semiconductor devices.

[0021] The heating block with uniform temperature according to the present invention. Other advantages, objects and features of the present invention will be partially reflected by the following description, and will also be understood by those skilled in the art through the research and practice of the present invention. Brief Description of the Drawings

[0022] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings:

[0023] Figure 1 is a schematic structural diagram of a heating element in the prior art;

[0024] Figure 2 is a schematic structural diagram of a heating element in a vacuum chamber in the prior art;

[0025] Figure 3 is a schematic structural diagram of the heating block with uniform temperature according to the present invention;

[0026] Figure 4 is at Figure 3 a magnified structural diagram of part A;

[0027] Figure 5 is a bottom view structural diagram of the heating element in the heating block with uniform temperature according to the present invention;

[0028] Figure 6 is a front view structural diagram of the heating element in the heating block with uniform temperature according to the present invention;

[0029] Figure 7 is a schematic diagram of the structure and its heat transfer path of the heating block with uniform temperature according to the present invention in a vacuum chamber;

[0030] Figure 8 is a schematic diagram of the temperature distribution of the heating element in a vacuum chamber in the prior art during heating;

[0031] Figure 9 is a schematic diagram of the temperature distribution of the heating block with uniform temperature according to the present invention in a vacuum chamber during heating. Detailed Description of the Embodiments

[0032] The present invention will be further described in detail below in conjunction with the drawings and embodiments, so that those skilled in the art can implement it according to the description in the specification.

[0033] It should be understood that the terms such as "having", "comprising" and "including" used herein do not exclude the presence or addition of one or more other elements or their combinations.

[0034] Such as Figure 3As shown in the figure, the present invention provides a heating block with uniform temperature, including: a heating body 1, the bottom of which is connected to a support body 3 through a cover body 2, and a heat insulation space 4 is formed between the heating body 1 and the cover body 2.

[0035] Inside the vacuum chamber 11, an O-ring seal 12 is provided between the support body 3 and the bottom inside the vacuum chamber 11. A cooling channel 13 is provided outside the bottom of the vacuum chamber 11. The support body 3 is not directly connected to the heating body 1. Instead, a cover body 2 is provided at the bottom of the heating body 1, and then the cover body 2 is connected to the support body 3. Moreover, a heat insulation space 4 is formed between the heating body 1 and the cover body 2 to play a heat insulation role, which can minimize the heat transferred from the heating body 1 to the cover body 2, so that the heating body 1 and the support body 3 do not directly transfer heat, and thus heat loss occurs indirectly.

[0036] Through the above structural design, the heat insulation space 4 can be used for heat insulation, maximizing the reduction of the directly contacting area between the heating body 1 and the cover body 2. By connecting the support body 3 and the cover body 2, indirect heat transfer between the heating body 1 and the support body 3 is achieved, enabling the heat of the heating body 1 to be transferred to the support body 3 with the least amount, reducing the heat loss of the heating body 1, and improving the temperature uniformity of the heating body 1.

[0037] The temperature distribution of the heating element in the prior art and the heating block of the present invention when working in the vacuum chamber 11 is as Figure 8 and Figure 9 shown;

[0038] Figure 8 In, the area with the highest surface temperature of the heating body 1 is distributed at its edge part ( Figure 8 the position on the upper left side in), the highest temperature is 429.04 °C, while the area with the lowest surface temperature of the heating body 1 is distributed at its central part, and the lowest temperature is 425.76 °C;

[0039] Figure 9 In, the area with the highest surface temperature of the heating body 1 is distributed at its central part, the highest temperature is 298.9 °C, and the area with the lowest surface temperature of the heating body 1 is distributed at its edge part ( Figure 9 the position on the lower right side in), the lowest temperature is 296.7 °C;

[0040] It can be seen that the temperature difference between the highest temperature and the lowest temperature of the heating element in the prior art when working in the vacuum chamber 11 is 3.28 °C, and the temperature difference between the highest temperature and the lowest temperature of the heating block of the present invention when working in the vacuum chamber 11 is 2.2 °C; and through Figure 8 and Figure 9 the temperature distribution colors in, Figure 8 it can be known that the temperature uniformity in is poor, while Figure 9 the temperature uniformity in is good.

[0041] Further, the heat insulation space 4 is arranged to communicate with the outside, so as to maintain a vacuum state inside the vacuum chamber 11;

[0042] Further, the cover body 2 is provided with a communication hole 22; at least four communication holes 22 are provided for communicating the heat insulation space 4 with the outside.

[0043] Or, the heat insulation space 4 is arranged as a vacuum space not communicating with the outside.

[0044] As Figure 4 shown, in one embodiment, an annular depression area 6 is formed on the outer periphery of the inner bottom surface of the cover body 2, and a neck 21 is formed on the side wall of the cover body 2 near the annular depression area 6.

[0045] Further, the thickness of the neck 21 is 3 mm to 10 mm;

[0046] Preferably, the thickness of the neck 21 is 5 mm.

[0047] The cover body 2 can be connected to the bottom of the heating body 1 in a welding form, and a groove is formed on the cover body 2, then a heat insulation space 4 is formed between the groove and the heating body 1. The annular depression area 6 makes a neck 21 formed on the cover body 2. The setting of the neck 21 is to minimize the heat transfer from the heating body 1 to the cover body 2;

[0048] The thickness of the neck 21 is less than the thickness of the rest of the cover body 2, and the heat conduction is reduced by reducing the cross-sectional area of heat transfer at the neck 21; since the cover body 2 also needs to support the heating body 1, in order to ensure the support strength at the neck 21 of the cover body 2 and maximize the reduction of heat conduction, the thickness of the neck 21 is preferably set to 5 mm.

[0049] Further, when the heat insulation space 4 is arranged as a vacuum space not communicating with the outside, the formed heat insulation space 4 combines the attributes of the cover body 2 to determine the vacuum standard, including: obtaining the structural characteristics of the cover body 2, and performing stress analysis on the cover body 2 to determine the ultimate stress of the cover body 2 when it deforms; performing ultimate pressure analysis according to the ultimate stress of the cover body 2 when it deforms and the size of the neck 21 through the following formula:

[0050]

[0051] In the above formula, P is the ultimate pressure of the heat-insulating space 4, P0 is the atmospheric pressure in the natural environment, σ is the ultimate stress of the deformation of the cover 2, d is the thickness of the neck 21, a is the radius of the neck 21 (the distance from the outer surface of the neck 21 to the axis of the heating body 1), and k is the range influence coefficient of the neck 21. The range influence coefficient of the neck 21 is determined according to the shape and boundary conditions of the neck 21, and its value ranges from 0 to 1. Furthermore, when forming the heat-insulating space 4, the pressure of the heat-insulating space 4 is controlled to be always greater than the ultimate pressure of the heat-insulating space 4.

[0052] The above determination by the vacuum standard enables the vacuum environment to be defined in combination with the vacuum standard when forming the heat-insulating space 4, avoiding the deformation of the cover 2 due to excessive vacuum (too small internal pressure) in the heat-insulating space 4, which affects the strength of the heating block, improving the formation accuracy of the heat-insulating space 4, and enabling the heat-insulating space 4 to better perform heat insulation without causing deformation of the cover 2.

[0053] As Figure 3 、 Figure 5 and Figure 6 shown, in one embodiment, a heating element 7 is arranged in the heating body 1, and the density of the heating element 7 arranged at the edge part of the heating body 1 is greater than the density of the heating element 7 arranged at the central part of the heating body 1.

[0054] The heating element 7 is arranged inside the heating body 1 by coiling a heating tube into a fixed shape. The heating element 7 has two lead wires, and the lead wires pass through the cover 2 and the support 3 in sequence from the bottom of the heating body 1. The end of the lead wire passing through the support 3 is connected to the power supply part through a terminal to enable the heating element 7 to be energized and heated;

[0055] Since the heat-insulating space 4 formed between the heating body 1 and the cover 2 can insulate heat, but the side wall of the cover 2 is also directly connected to the heating body 1, and direct heat transfer will occur at the directly connected part between the two. Therefore, the heat loss at the edge of the heating body 1 will be greater than the heat loss at the middle part of the heating body 1;

[0056] Due to the reason of the structure of the heating element 7 itself, it is difficult to increase the density of the arrangement of the heating element 7 at the central part of the heating body 1, and this method cannot directly solve the problems in the prior art. Therefore, when configuring the heating element 7, the density of the coiled heating tube at the edge part of the heating body 1 is made greater than the density at the central part, that is, the gap of the coiled heating tube in the fixed shape at the edge part of the heating body 1 is smaller than the gap at the central part. In this way, when the heating body 1 works, the heating element 7 generates more heat at the edge part to make up for the more heat loss at the edge part of the heating body 1, so as to improve the temperature uniformity on the surface of the heating body 1, and thus the uniformity and consistency of the thickness of the deposited film in the chemical vapor deposition process are better, improving the yield rate and quality reliability of semiconductor devices.

[0057] Further, when the heating tubes are coiled into a fixed shape and arranged inside the heating body 1, a simulation is carried out for the heating tubes combined with the heating block (simulating the environment when the heating block shown in Figure 7 works actually), tests are carried out with different coiling densities, test data are obtained, data analysis is carried out on the test data, the heating characteristics of the heating block are determined (the heating characteristics at least include the surface temperature uniformity of the heating body 1 and the heat loss at the edge of the heating body 1), the coiling density of the heating tubes is finely adjusted according to the heating characteristics of the heating block (mainly adjusting the coiling density on the outer periphery of the heating tubes), the adjusted coiling density of the heating tubes is obtained, and then a re-test is carried out based on the adjusted coiling density of the heating tubes combined with the heating block until the temperature on the surface of the heating body 1 is uniform. The adjusted coiling density of the heating tubes at this time is used as the target coiling density of the heating tubes, and then when arranging the heating tubes inside the heating body 1, they are fixedly arranged according to the target coiling density of the heating tubes.

[0058] Through the above simulation of the heating tubes combined with the heating block, the coiling heating characteristics of the heating tubes are clarified, so that the surface temperature of the heating body 1 fixed inside based on the target coiling density of the heating tubes is more uniform during heating, the temperature uniformity of the surface of the heating body 1 is ensured, and further the uniformity and consistency of the thickness of the film deposited in the chemical vapor deposition process are better, improving the yield rate and quality reliability of semiconductor devices.

[0059] As shown in Figure 3 and Figure 7 shown, further, the support body 3 includes: an inner rod body 31 connected to the cover body 2, an outer rod body 32 is arranged outside the inner rod body 31, and a contact ring 5 is arranged outside the outer rod body 32.

[0060] The bottom surface of the contact ring 5 is hermetically connected to the vacuum chamber 11 through an O-ring 12.

[0061] As shown in Figure 3 shown, further, there is an isolation gap 8 between the top surface of the outer rod body 32 and the bottom surface of the cover body 2, a heat insulation zone 9 is arranged in the upper part between the inner rod body 31 and the outer rod body 32, and the heat insulation zone 9 communicates with the isolation gap 8.

[0062] As shown in Figure 7 shown, further, the heat transfer path between the heating body 1 and the support body 3 is: the heating body 1, the cover body 2, the inner rod body 31, the outer rod body 32 and the contact ring 5.

[0063] The isolation gap 8 makes the outer rod body 32 not in contact with the cover body 2, the heat insulation zone 9 makes the upper part of the outer rod body 32 not in contact with the upper part of the inner rod body 31, and the lower parts of the outer rod body 32 and the inner rod body 31 are connected and in contact (threaded connection or other methods can be used);

[0064] Inside the vacuum chamber 11, due to the vacuum environment, both the heat insulation zone 9 and the isolation gap 8 are in a vacuum environment. This makes the top surface of the outer rod body 32 and the cover body 2, as well as the upper part between the outer rod body 32 and the inner rod body 31, in a vacuum, which can effectively insulate the outer rod body 32 and the cover body 2 thermally in a vacuum, and insulate the outer rod body 32 and the upper part of the inner rod body 31 thermally in a vacuum. This increases the heat transfer path on the support body 3, thereby reducing the heat transfer on the support body 3 and further reducing the heat loss of the heating body 1.

[0065] The heat insulation zone 9 can make the heat transfer path (heat loss path) on the support body 3 as long as possible, and at the same time, it is necessary to ensure the connection strength between the outer rod body 32 and the inner rod body 31 to ensure the support strength for the heating body 1.

[0066] There are various ways to form the heat insulation zone 9:

[0067] First, an inner ring groove is provided on the inner ring wall of the outer rod body 32, and the heat insulation zone 9 is formed between the inner ring groove and the outer ring wall of the inner rod body 31.

[0068] Second, an outer ring groove is provided on the outer ring wall of the inner rod body 31, and the heat insulation zone 9 is formed between the outer ring groove and the inner ring wall of the outer rod body 32.

[0069] Third, an inner ring groove is provided on the inner ring wall of the outer rod body 32, and an outer ring groove is provided on the outer ring wall of the inner rod body 31, and the heat insulation zone 9 is formed between the inner ring groove and the outer ring groove.

[0070] The above three methods can all form the heat insulation zone 9. The heat insulation zone 9 is annular, and the purpose is to completely isolate and non-contact the upper parts of the outer rod body 32 and the inner rod body 31 to extend the heat transfer path on the support body 3.

[0071] In the description of the present invention, it should be understood that 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. indicate the orientation or positional relationship 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 cannot be understood as a limitation to the present invention.

[0072] In the present invention, unless otherwise clearly specified or defined, the terms "installed", "connected", "joined", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or capable of communicating with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] Although the embodiments of the present invention have been disclosed as above, it is not limited to only the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the present invention, the present invention is not limited to specific details and the examples shown and described herein.

Claims

1. A heating block with uniform temperature, characterized in that, Comprising: A heating body (1), the bottom of which is connected to a support body (3) through a cover body (2), and a heat insulation space (4) is formed between the heating body (1) and the cover body (2).

2. The temperature-uniform heating block according to claim 1, wherein An annular recessed area (6) is formed on the outer periphery of the inner bottom surface of the cover body (2), and a neck (21) is formed on the side wall of the cover body (2) near the annular recessed area (6).

3. The temperature-uniform heating block according to claim 2, wherein The thickness of the neck (21) is 3 mm to 10 mm.

4. The temperature-uniform heating block according to claim 3, characterized in that The thickness of the neck (21) is 5 mm.

5. The temperature-uniform heating block according to claim 2, wherein A heating element (7) is arranged in the heating body (1), and the density of the heating element (7) arranged at the edge part of the heating body (1) is greater than the density of the heating element (7) arranged at the central part of the heating body (1).

6. The temperature-uniform heating block according to claim 1, wherein, The support body (3) includes: an inner rod body (31) connected to the cover body (2), an outer rod body (32) is arranged outside the inner rod body (31), and a contact ring (5) is arranged outside the outer rod body (32).

7. The temperature-uniform heating block according to claim 6, wherein An isolation gap (8) is left between the top surface of the outer rod body (32) and the bottom surface of the cover body (2), and a heat insulation area (9) is arranged in the upper part between the inner rod body (31) and the outer rod body (32), and the heat insulation area (9) is communicated with the isolation gap (8).

8. The temperature-uniform heating block according to claim 1, wherein, A communication hole (22) is arranged on the cover body (2).

9. The temperature-uniform heating block according to claim 7, wherein, An inner ring groove is arranged on the inner ring wall of the outer rod body (32), and a heat insulation area (9) is formed between the inner ring groove and the outer ring wall of the inner rod body (31); Or, an outer ring groove is arranged on the outer ring wall of the inner rod body (31), and a heat insulation area (9) is formed between the outer ring groove and the inner ring wall of the outer rod body (32).

10. The temperature-uniform heating block according to claim 7, wherein The heat transfer path between the heating body (1) and the support body (3) is: the heating body (1), the cover body (2), the inner rod body (31), the outer rod body (32) and the contact ring (5).

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