Vertical batch furnace assembly including a supply of cooling gas

Abstract

A vertical batch furnace assembly includes a core tube, a housing, a cooling chamber defined by and enclosed by the housing and the core tube, and at least one cooling gas supply emanating in the cooling chamber. The core tube has an elongated circumferential wall extending in a longitudinal direction and is configured to house a wafer for processing in the vertical batch furnace assembly. The housing extends around the core tube and includes a heating element for applying a heat treatment to the wafer housed in the core tube. The at least one cooling gas supply includes at least one cooling gas supply opening arranged such that cooling gas enters the cooling chamber in a flow direction substantially tangential to the circumferential wall.

Description

Technical Field

[0001] This disclosure generally relates to a vertical batch furnace assembly including a cooling gas supply. Background Technology

[0002] Most vertical batch furnaces are equipped with a die tube configured to hold wafers to be processed within the furnace. During processing in a vertical batch furnace, both the wafers and the die tube can become hot. To increase the throughput of the vertical batch furnace assembly, the die tube can be cooled. Cooling gas can be supplied from multiple circumferentially spaced openings on the side of a cooling chamber between the circumferential wall of the die tube and the housing. Summary of the Invention

[0003] This summary is provided to present the chosen concepts in a simplified form. These concepts are further described in detail in the following description of exemplary embodiments of this disclosure. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0004] It can be recognized that circumferentially spaced openings can locally generate cold spots on the circumferential walls of the die. Such cold spots can lead to temperature differences within the circumferential walls, which may cause stress within the circumferential walls. Furthermore, the wafer inside the die may also be exposed to temperature differences, which could lead to wafer breakage.

[0005] Therefore, the object of the present invention is to provide a vertical batch furnace assembly that can alleviate the above-mentioned problems.

[0006] To this end, a vertical batch furnace assembly can be provided. More specifically, a vertical batch furnace assembly can be provided, comprising a die tube, a housing, a cooling chamber defined and surrounded by the housing and the die tube, and at least one cooling gas supply emanating from the cooling chamber. The die tube may have an elongated circumferential wall extending in a longitudinal direction, and the die tube may be configured to receive a wafer for processing in the vertical batch furnace assembly. The housing may extend around the die tube and may include heating elements for applying heat treatment to the wafer received in the die tube. The cooling gas supply may include at least one cooling gas supply opening arranged such that cooling gas enters the cooling chamber in a flow direction substantially tangential to the circumferential wall.

[0007] A method for cooling a vertical batch processing furnace can also be provided. More specifically, a method can be provided comprising: providing a vertical batch processing furnace 10 according to the specification; and supplying cooling gas in a cooling chamber 20 along a flow direction substantially tangential to the circumferential wall. The substantially tangential flow direction may include an angle ranging from 90° ± 15° to the longitudinal direction of the elongated circumferential wall 14, and may include an angle ranging from 0° ± 10° to the plane passing through the point closest to the corresponding cooling gas supply opening of the circumferential wall and tangential to the circumferential wall.

[0008] To summarize the invention and the advantages obtained compared to the prior art, certain objects and advantages of the invention have been described above. It should be understood, of course, that not all of these objects or advantages may necessarily be achieved according to any particular embodiment of the invention. Therefore, for example, those skilled in the art will recognize that the invention may be practiced or performed in a manner that achieves or optimizes one or more advantages taught or implied herein, without necessarily achieving other objects or advantages that may be taught or implied herein.

[0009] Various embodiments are claimed in the dependent claims, and these embodiments will be further illustrated with reference to the examples shown in the accompanying drawings. The embodiments may be used in combination or separately from each other.

[0010] All these embodiments are intended to fall within the scope of the invention disclosed herein. These and other embodiments will become apparent to those skilled in the art from the following detailed description of certain embodiments with reference to the accompanying drawings, and the invention is not limited to any particular embodiment disclosed. Attached Figure Description

[0011] Although the specification concludes with claims that specifically point out and expressly claim protection for embodiments of the invention, the advantages of the embodiments of the present disclosure can be more readily determined from the description of certain examples of embodiments of the present disclosure when read in conjunction with the accompanying drawings, wherein:

[0012] Figure 1 An example of a vertical batch furnace assembly is shown according to the instruction manual;

[0013] Figure 2 yes Figure 1 A top view of the top portion of the example shell;

[0014] Figure 3 schematically shown Figure 2 Detailed exploded perspective view; and

[0015] Figure 4 A schematic cross-sectional view of an example of the end portion of the cooling gas inlet pipe according to the instruction manual is shown. Detailed Implementation

[0016] In this application, similar or corresponding features are indicated by similar or corresponding reference numerals. The description of various embodiments is not limited to the examples shown in the drawings, and the reference numerals used in the detailed description and claims are not intended to limit the description of the embodiments, but are included to clarify the embodiments.

[0017] While certain embodiments and examples are disclosed below, those skilled in the art will understand that the invention extends beyond the specific embodiments and / or uses disclosed herein and their obvious modifications and equivalents. Therefore, it is intended that the scope of the disclosed invention should not be limited to the specific disclosed embodiments described below. The illustrations presented herein are not intended to be actual views of any particular material, structure, or device, but are merely idealized representations used to describe embodiments of this disclosure.

[0018] As used herein, the term “wafer” can refer to any one or more of the following materials that can be used, or materials on which devices, circuits or films can be formed.

[0019] In the most general sense, this disclosure may provide a vertical batch furnace assembly 10. The vertical batch furnace assembly 10 may include a die tube 12, a housing 16, a cooling chamber 20 defined radially outward by the housing 16 and radially inward by the die tube 12, and at least one cooling gas supply emanating from the cooling chamber 20. The die tube 12 may have an elongated circumferential wall 14 extending in a longitudinal direction L, and the die tube 12 may be configured to receive a wafer for processing in the vertical batch furnace assembly 10. The housing 16 may extend around the die tube 12 and may include a heating element 18 for applying heat treatment to the wafer received in the die tube 12. The cooling gas supply may include at least one cooling gas supply opening 26 configured such that cooling gas enters the cooling chamber 20 in a flow direction substantially tangential to the circumferential wall 14. The substantially tangential flow direction may include an angle ranging from 90° ± 15° to the longitudinal direction L of the elongated circumferential wall 14. The substantially tangential flow direction may include an angle ranging from 0° to 10° with the plane of the point through which the corresponding cooling gas supply opening 26 is closest to and tangent to the circumferential wall 14.

[0020] When the flow direction of the gas exiting the gas supply opening 26 is at least initially tangent to the circumferential wall 14, the cooling gas will not immediately flow along the longitudinal direction of the elongated circumferential wall 14, but will instead disperse along the tangential direction of the circumferential wall 14. Only after the cooling gas has dispersed along the tangential direction of the circumferential wall 14 will it flow along the longitudinal direction L of the elongated circumferential wall 14, as... Figure 1 As indicated by arrow F in the diagram. By first distributing the cooling gas tangentially, the circumferential wall 14 is cooled more uniformly. In this way, cold spots are not formed, and the disadvantages associated with these so-called cold spots are prevented.

[0021] In one embodiment, an example is shown in Figure 3 As shown in the exploded view, each cooling gas supply may include a cooling gas inlet pipe 22, the end portion 24 of which extends into the cooling chamber 20. Similarly, in... Figure 4 The end portion 24 shown may be provided with at least one cooling gas supply opening 26. Each cooling gas inlet pipe 22 may be made from a single piece. Each cooling gas inlet pipe 22 may be made of ceramic material. The axial end portion 28 of the cooling gas inlet pipe 22 extending into the cooling chamber 20 may be closed.

[0022] exist Figure 4 In the example shown, the cooling gas inlet pipe 22 extends into the cooling chamber 20. The cooling gas inlet pipe 22 may extend through an opening 44 in the housing 16. By closing the axial end portion 28 of the cooling gas inlet pipe 22, cooling gas is prevented from entering the cooling chamber 20 parallel to the longitudinal direction of the elongated circumferential wall 14. The end portion of the cooling gas inlet pipe 22 shown is provided with two cooling gas supply openings 26. Each supply opening is oriented such that cooling gas entering the cooling chamber 20 via said opening enters the cooling chamber 20 tangentially relative to the circumferential wall 14. The cooling gas inlet pipe 22 may be provided with a cam 46 arranged to cooperate with a corresponding recess 48 in the housing 16, which is part of the opening 44 through which the cooling gas inlet pipe 22 extends. The combination of the cam 46 on the cooling gas inlet pipe 22 and the recess 48 in the housing 16 fixes the orientation of the cooling gas inlet pipe 22 relative to the housing 16 and therefore also relative to the vertical batch furnace assembly 10 and the core tube 12. This ensures that the cooling gas supply opening 26 will be correctly oriented relative to the core tube 12, so that the cooling gas will enter the cooling chamber 20 in a flow direction substantially tangential to the circumferential wall 14.

[0023] During wafer processing in the die tube 12, the cooling gas inlet tube 22 can be heated. When cooling begins, the supplied cooling gas can cause a significant drop in temperature of the cooling gas inlet tube 22. This temperature drop may lead to internal stress within the cooling gas inlet tube 22. By implementing the cooling gas inlet tube 22 as a single, integral part, there are no weak joints within it, which could cause the cooling gas inlet tube 22 to crack due to this internal stress. Preferably, each cooling gas inlet tube 22 is made of a ceramic material. Ceramic materials can withstand high temperatures and large temperature fluctuations. This makes ceramic materials ideally suited for the cooling gas inlet tube 22.

[0024] exist Figure 2In the embodiment shown as an example, at least one cooling gas supply 22 comprises a plurality of cooling gas supplies uniformly spaced around the core tube 12. By uniformly spaced the cooling gas supplies around the core tube 12, a uniform inflow of cooling gas along the elongated circumferential wall 14 can be achieved.

[0025] exist Figure 1 In an embodiment illustrating this example, the vertical batch furnace assembly 10 may further include at least one cooling gas exhaust 30, which includes at least one exhaust opening 31 for discharging cooling gas from the cooling chamber 20. During operation, the emitted cooling gas can flow from at least one cooling gas supply along the elongated circumferential wall 14 of the core tube 12 to at least one cooling gas exhaust 30.

[0026] At least one cooling gas outlet 30 may include a plurality of cooling gas outlets 30 uniformly spaced around the core tube 12. By uniformly spaced the cooling gas outlets 30 around the core tube 12, a uniform flow of cooling gas along the elongated circumferential wall 14 is achieved.

[0027] like Figure 1 As shown, at least one cooling gas supply can be arranged at or near the first longitudinal end 32 of the cooling chamber 34, and at least one cooling gas discharge 30 can be arranged at or near the second longitudinal end of the cooling chamber 34. Thus, the cooling gas will flow parallel to the longitudinal direction along the elongated circumferential wall 14, as indicated by arrow F.

[0028] The vertical batch furnace assembly 10 may further include a cooling gas recirculation passage 36 extending from at least one cooling gas exhaust 30 to at least one cooling gas supply 22. The cooling gas recirculation passage 36 may include a pressure increasing device 38, such as a fan or blower, and a heat exchanger 40 configured to cool the cooling gas in the recirculation passage 36. By recirculating the cooling gas, it is reused, meaning that new cooling gas does not need to be supplied. This is particularly advantageous when the cooling gas is not ambient air but, for example, concentrated nitrogen that must be purchased and whose supply may run out. Furthermore, since new cooling gas is not always introduced into the cooling chamber 20, debris or contaminants will not enter the cooling chamber 20. Similarly, harmful contaminants originating from the cooling chamber or other parts of the vertical batch furnace assembly 10 will not be released into the surrounding environment along with the cooling gas.

[0029] Preferably, the pressure increasing device 38 can be arranged downstream of the heat exchanger 40. It may be desirable to maintain a certain pressure at the cooling gas supply opening 26. By arranging the pressure increasing device 38 downstream of the heat exchanger 40, the pressure increasing device 38 requires less power to achieve a certain pressure at the cooling gas supply opening 26, which is the opposite of arranging the pressure increasing device 38 upstream of the heat exchanger 40.

[0030] The configuration of at least one cooling gas outlet 30 can be similar to the configuration of at least one cooling gas supply, wherein the flow direction of the cooling gas within the cooling chamber 20 is reversible. At least one cooling gas outlet opening can be configured such that when the flow direction of the cooling gas within the cooling chamber 20 is reversed and the cooling gas outlet opening is used as a cooling gas supply opening 26, the cooling gas enters the cooling chamber 20 in a flow direction substantially tangential to the circumferential wall 14.

[0031] Cooling gas can cool the core tube 12 by absorbing heat from it. When flowing in one direction, the cooling gas is coldest when entering the cooling chamber 20 and hottest when leaving through the cooling gas exhaust 30. This means that the portion of the circumferential wall 14 closest to the cooling gas exhaust 30 will be cooled by the cooling gas to a lesser extent than the portion of the circumferential wall 14 closer to the cooling gas supply pipe 22. To improve the overall cooling rate of the elongated circumferential wall 14, it may be beneficial to have the cooling gas also flow from the cooling gas exhaust 30 to the cooling gas supply. The cooling gas can then flow from the cooling gas supply along the circumferential wall 14 to the cooling gas exhaust 30 for a certain period of time, thereby primarily cooling the portion of the circumferential wall 14 closest to the cooling gas supply. After said certain period of time, the flow direction can be reversed, and the cooling gas can flow from the cooling gas exhaust 30 along the circumferential wall 14 to the cooling gas supply 22 for a certain period of time, thereby primarily cooling the portion of the circumferential wall 14 closest to the cooling gas exhaust 30. In this way, the overall cooling efficiency of the cooling gas flow is improved.

[0032] exist Figure 1 In the example shown, this flow reversal can be achieved because the inlet of the pressure increasing device 38 can be connected to two suction sections 36b of the recirculation channel 36. Each suction section 36b may include discharge valves 52a, 52b. The outlet of the pressure increasing device 38 can be connected to the pressure section 36a of the recirculation channel 36. The supply section 36a of the cooling gas recirculation channel 36 is divided into two parts, and each part may include diverter valves 42a, 42b. In use, only one suction section 36b may be the operating transport cooling gas, while the other may be closed by the associated discharge valve 52a or 52b. By cleverly switching the diverter valves 42a, 42b and the discharge valves 52a, 52b, the cooling gas can be directed to at least one cooling gas supply 22 and subsequently directed via the cooling chamber 20 to at least one cooling gas discharge 30, or alternatively, directed to at least one cooling gas discharge 30 and subsequently directed via the cooling chamber 20 to at least one cooling gas supply 22.

[0033] Besides being functionally identical, the cooling gas exhaust 30 can also be structurally identical to the cooling gas supply 22. This is advantageous for constructing both the cooling gas exhaust 30 and the cooling gas supply 22, as only one type of component needs to be manufactured.

[0034] This disclosure may also provide a method for cooling a vertical batch furnace. The method may include providing a vertical batch furnace 10 according to the specification, and supplying cooling gas in a cooling chamber 20 in a flow direction substantially tangential to the circumferential wall 14.

[0035] In an embodiment, the substantially tangential flow direction includes an angle ranging from 90° ± 15° with respect to the longitudinal direction L of the elongated circumferential wall 14.

[0036] In an embodiment, the substantially tangential flow direction includes an angle ranging from 0° to 10° with the plane of the point closest to the corresponding cooling gas supply opening 26 through the circumferential wall and tangent to the circumferential wall 14.

[0037] When the initial flow is tangential to the circumferential wall 14, the cooling gas will not immediately flow along the longitudinal direction L of the elongated circumferential wall 14, but will instead be distributed along the tangential direction of the circumferential wall 14. Only after the cooling gas has been distributed along the tangential direction of the circumferential wall 14 will it flow along the longitudinal direction L of the elongated circumferential wall 14. This prevents the formation of cold spots and avoids the disadvantages associated with these so-called cold spots.

[0038] Although illustrative embodiments of the invention have been described above in part with reference to the accompanying drawings, it should be understood that the invention is not limited to these embodiments. By studying the drawings, the disclosure, and the appended claims, those skilled in the art will understand and implement variations of the disclosed embodiments in practicing the claimed invention.

[0039] Throughout this specification, references to "an embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in an embodiment" or "in one embodiment" appearing throughout the specification do not necessarily refer to the same embodiment.

[0040] Furthermore, it should be noted that one or more specific features, structures, or characteristics in the various embodiments described above can be used independently of each other and can be combined in any suitable manner to form new embodiments not explicitly described. The reference numerals used in the detailed description and claims do not limit the description of the embodiments or the claims. The reference numerals are for clarification only.

[0041] List of reference numerals

[0042] 10 – Vertical Batch Processing Furnace Assembly

[0043] 12-core tube

[0044] 14 – Circumferential Wall

[0045] 16 – Casing

[0046] 18 – Heating element

[0047] 20 – Cooling Chamber

[0048] 22 – Cooling gas inlet pipe

[0049] 24 – (End portion of the cooling gas inlet pipe)

[0050] 26 – Cooling air supply opening

[0051] 28 – Axial end of (cooling gas inlet pipe)

[0052] 30 – Cooling gas emissions

[0053] 32 – (First longitudinal end of the cooling chamber)

[0054] 34 – (second longitudinal end of the cooling chamber)

[0055] 36 – Cooling gas recirculation channel

[0056] 38 – Pressure Increasing Device

[0057] 40 – Heat Exchanger

[0058] 42a – Flow divider valve

[0059] 42b – Flow divider valve

[0060] 44 – (Opening in the casing)

[0061] 46-cam

[0062] 48 – Recess

[0063] 52a – Discharge Valve

[0064] 52b – Discharge Valve

[0065] L – Longitudinal direction

Claims

1. A vertical batch processing furnace assembly (10), comprising: - A core tube (12) having an elongated circumferential wall (14) extending in the longitudinal direction, wherein the core tube (12) is configured to accommodate a wafer for processing in a vertical batch furnace assembly (10); - A housing (16) extending around the core tube (12) and including a heating element (18) for applying heat treatment to the wafer housed in the core tube (12); - Cooling chamber (20), which is defined radially outward by outer shell (16) and radially inward by core tube (12); - At least one cooling gas supply, emanating from a cooling chamber (20), wherein the cooling gas supply includes at least one cooling gas supply opening (26) configured such that cooling gas enters the cooling chamber (20) in a flow direction substantially tangential to the circumferential wall (14); and - At least one cooling gas outlet (30), said at least one cooling gas outlet comprising at least one outlet opening for discharging cooling gas from the cooling chamber, wherein, in operation, the emitted cooling gas flows from at least one cooling gas supply along the elongated circumferential wall of the core tube to at least one cooling gas outlet. A cooling gas recirculation channel extending from the at least one cooling gas discharge to the at least one cooling gas supply, the cooling gas recirculation channel comprising: - Pressure increasing device; and - A heat exchanger configured to cool the cooling gas in the recirculation channel. The configuration of the at least one cooling gas discharge is the same as the configuration of the at least one cooling gas supply, wherein the flow direction of the cooling gas in the cooling chamber is reversible, and wherein the at least one cooling gas discharge opening is configured such that when the flow direction of the cooling gas in the cooling chamber is reversed and the cooling gas discharge opening is used as a cooling gas supply opening, the cooling gas enters the cooling chamber in a flow direction substantially tangential to the circumferential wall.

2. The vertical batch processing furnace assembly according to claim 1, wherein, The fundamentally tangential flow direction includes an angle ranging from 90° ± 15° with the longitudinal direction of the elongated circumferential wall (14).

3. The vertical batch processing furnace assembly according to claim 1 or 2, wherein, The fundamentally tangential flow direction includes an angle of 0° ± 10° with respect to a plane that passes through a point on the circumferential wall that is closest to the corresponding cooling gas supply opening (26) and is tangential to the circumferential wall.

4. The vertical batch processing furnace assembly according to claim 1 or 2, wherein, Each cooling gas supply includes a cooling gas inlet pipe (22) with an end portion (24) extending into the cooling chamber (20), wherein the end portion (24) is provided with the at least one cooling gas supply opening (26).

5. The vertical batch processing furnace assembly according to claim 4, wherein, Each cooling gas inlet pipe (22) is implemented as a single unit.

6. The vertical batch processing furnace assembly according to claim 4, wherein, Each cooling gas inlet pipe (22) is made of ceramic material.

7. The vertical batch processing furnace assembly according to claim 4, wherein, The axial end (28) of the cooling gas inlet pipe (22) extending into the cooling chamber (20) is closed.

8. The vertical batch processing furnace assembly according to claim 1 or 2, wherein, The at least one cooling gas supply includes a plurality of cooling gas supplies evenly spaced around the core tube (12).

9. The vertical batch processing furnace assembly according to claim 1, wherein, The at least one cooling gas discharge (30) includes a plurality of cooling gas discharges (30) evenly spaced around the core tube (12).

10. The vertical batch processing furnace assembly according to claim 1, wherein, The at least one cooling gas supply is arranged at or near the first longitudinal end (32) of the cooling chamber, and the at least one cooling gas discharge (30) is arranged at or near the second longitudinal end of the cooling chamber (20).

11. The vertical batch processing furnace assembly according to claim 1, wherein, The pressure increasing device is a fan or blower.

12. The vertical batch processing furnace assembly according to claim 1, wherein, The pressure increasing device (38) is arranged downstream of the heat exchanger (40).

13. The vertical batch processing furnace assembly according to claim 1, wherein, The cooling gas recirculation channel (36) includes a diversion valve (42a, 42b) and / or a discharge valve (52a, 52b) to direct cooling gas to the at least one cooling gas supply and then via the cooling chamber (20) to the at least one cooling gas discharge (30), or alternatively, to direct cooling gas to the at least one cooling gas discharge (30) and then via the cooling chamber (20) to the at least one cooling gas supply.

14. A method for cooling a vertical batch processing furnace, comprising: - Provides a vertical batch furnace assembly (10) according to any one of claims 1-13; as well as - Cooling gas is supplied in the cooling chamber (20) along a flow direction that is substantially tangential to the circumferential wall.

15. The method according to claim 14, wherein, The fundamentally tangential flow direction includes an angle ranging from 90° ± 15° with the longitudinal direction of the elongated circumferential wall (14).

16. The method according to claim 14 or 15, wherein, The fundamentally tangent flow direction includes an angle ranging from 0° to 10° with the plane of the point closest to the corresponding cooling gas supply opening (26) through the circumferential wall and tangent to the circumferential wall.

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