Flange and apparatus for processing substrates

Abstract

The present disclosure relates to a flange for a process tube in an apparatus for processing substrates, such as a vertical furnace. The flange can be provided with an opening for accessing a process chamber of the process tube in use and a cooling channel for allowing a cooling fluid to flow therethrough and cool the flange. A material having a thermal conductivity between 0.1 and 40 W / m K can be at least partially disposed between the cooling fluid and the remainder of the flange.

Description

Technical Field

[0001] This disclosure relates to a flange for a processing tube in an apparatus for processing a substrate. The flange may be provided with an opening for access to the interior of the processing tube during use, and a cooling passage for allowing cooling fluid to flow and cool the flange.

[0002] More specifically, this disclosure relates to an apparatus for processing a substrate, comprising:

[0003] The processing tube forms a processing chamber and has an opening at its lower end;

[0004] A heater that surrounds the processing tube for heating the processing tube;

[0005] A flange for a processing pipe, comprising an opening aligned with the opening of the processing pipe and a seal sealing the processing chamber; and

[0006] Cooling channels are used to allow cooling fluid to flow through them and cool the seals. Background Technology

[0007] Semiconductor substrates can be processed in batches in vertical furnaces. An example of this process is the deposition of various material layers on the substrate. For various reasons, including the uniformity of electrical and physical properties, the deposited layers typically require high purity and uniformity. However, the deposition results can be adversely affected by the presence of particulate matter in the furnace. In some cases, particles may remain on or bind to the layer, thereby reducing the purity and uniformity of the deposited layer. Therefore, to consistently obtain high-quality processing results, processing methods and systems capable of consistently achieving low particle levels are needed.

[0008] The particles may be a result of reaction byproducts that condense at lower temperatures on a flange near the opening of the processing tube. Therefore, during processing, the flange temperature can be maintained at an elevated level to prevent condensation. However, when the hot wafer load is unloaded from the reaction tube, the heat load may radiate heat to the flange, potentially further heating it. The O-rings used to seal the flange to the tube or other furnace components may overheat and begin to leak due to this overheating. To prevent overheating, the flange can be equipped with temperature control. Summary of the Invention

[0009] This summary is provided to present the selected concepts in a simplified form. These concepts are further described in detail in the following detailed description of exemplary embodiments disclosed. 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.

[0010] The aim is to provide a flange with improved temperature control, thereby preventing overheating of the seals and / or excessive condensation of byproducts.

[0011] According to one aspect, a flange for a processing tube in an apparatus for processing a substrate can be provided. The flange is provided with an opening for access to a processing chamber of the processing tube during use, and a cooling channel for allowing cooling fluid to flow through and cool the flange. A material with a thermal conductivity between 0.1 and 40 W / m K is at least partially disposed between the cooling fluid and the remainder of the flange.

[0012] According to another aspect, an apparatus for processing a substrate can be provided, comprising:

[0013] The processing tube forms a processing chamber and has an opening at its lower end;

[0014] A heater that surrounds the processing tube for heating the processing tube;

[0015] A flange for a processing pipe, comprising an opening aligned with the opening of the processing pipe and a seal sealing the processing chamber; and

[0016] Cooling channels are used to allow cooling fluid to flow through and cool the seals. Materials with thermal conductivity between 0.1 and 40 W / m K can be at least partially disposed between the cooling fluid and the seals.

[0017] To summarize the invention and its advantages over 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 as taught or suggested herein, without necessarily achieving other objects or advantages as taught or suggested herein.

[0018] All of these embodiments are 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

[0019] Although this specification concludes with claims, which specifically point out and clearly claim protection for what are considered embodiments of the invention, the advantages of the embodiments of this disclosure can be more readily determined from the description of certain examples of embodiments when read in conjunction with the accompanying drawings, wherein:

[0020] Figure 1 This is a schematic diagram of the lower end of the processing tube of a vertical furnace in the off state.

[0021] Figure 2This is a detailed cross-sectional view of the cooling passage in the flange according to an embodiment.

[0022] Figure 3 This is a schematic cross-sectional view of the cooling passage in the flange according to an embodiment.

[0023] Figure 4 This is a schematic top view of the cooling channel according to an embodiment. Detailed Implementation

[0024] Although certain embodiments and examples are disclosed below, those skilled in the art will understand that the invention extends beyond the specific disclosed embodiments and / or uses of the invention 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 given 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.

[0025] As used herein, the terms “substrate” or “wafer” can refer to any underlying material that may be used, or a material on which devices, circuits, or films may be formed. The term “semiconductor device structure” can refer to any portion of a semiconductor structure that is, includes, or defines at least a portion of the active or passive components of a semiconductor device to be formed on or in a semiconductor substrate.

[0026] Semiconductor substrates can be processed in batches in a vertical furnace. An example of this process is the deposition of various material layers on the substrate. For instance, some processes can be based on chlorides and ammonia. Chloride-based chemicals using ammonia may readily form particles. Without being theoretically limited, it can be assumed that particle formation is a result of NH4Cl condensing at the furnace cold point (typically on the flange). Therefore, the flange may be heated to a sufficiently high temperature to prevent NH4Cl condensation. Other processes may be prone to condensation problems and also require heating the flange. The flange can be heated to, for example, 100°C or higher, more preferably 120°C or higher, even more preferably 150°C or higher, and most preferably 180°C or higher.

[0027] As described above, in addition to being heated, flanges can typically be cooled, for example, to prevent thermal damage to the O-rings used to seal the flange. While the cooling system preferably effectively prevents the substrate from overheating, it preferably does not cool the flange so much that it might be cooled below the temperature required to prevent condensation. In view of these conflicting requirements, a preferred embodiment of the invention provides a cooling system that can effectively and uniformly cool flanges or other furnace structures without overcooling.

[0028] The flange can be equipped with a fluid cooling system, in which the fluid, preferably water, flows through a channel. The channel can be located within the space of the flange and can be partially away from the wall of the space. Where the channel adjoins the wall of the space, there may be a main conduit for heat transfer between the flange and the channel. Using an effective cooling medium, such as unheated water at room temperature or below room temperature, can promote adequate cooling. Advantageously, such a cooling system can be particularly simple and effective. It has been found that using limited contact between the channel and the wall is more reliable and simpler than using heated cooling media such as warm or hot water or heated glycol to prevent the flange from overcooling. This also helps prevent the cooling medium from overheating, which can ultimately lead to degradation or boiling of the cooling fluid, or the formation of deposits in the channel through which the cooling medium flows.

[0029] Figure 1 , 2 Figures 3 and 4 schematically illustrate a portion of an exemplary batch reactor. The reactor shown may be a vertical furnace-type reactor, which is advantageous for efficient heating and loading sequence, but those skilled in the art will understand that the principles and advantages disclosed herein can be applied to other types of reactors.

[0030] Figure 1 A cross-sectional side view of the lower portion of the processing tube 10 of the vertical furnace 100 is shown. The processing tube 10 may be open at the bottom and closed at the top (not shown) in a dome shape. The processing tube 10 may define a processing chamber 12. A heater 20 may surround the processing tube 10 for heating the processing tube. A base 30 may support a wafer boat 40, which holds a plurality of wafers 50, preferably 50 or more wafers. The base 30 may be thermally insulated to prevent overheating of the surrounding portion of the vertical furnace 100, including the door plate 90 supporting the base 30.

[0031] The treatment tube 10 (showing only its bottom end) may have a widened base 11, which can be supported on a flange, such as an upper flange 80 or a lower flange 82. Additional flanges may be used around the treatment tube 10 to seal it. Flanges may also be used to support other components in the treatment tube, such as syringes or bushings.

[0032] Flanges 80 and 82 may have generally circular openings for access to the interior of the processing tube 10 during use, to move, for example, a generally circular base 30 with a wafer boat 40 that holds multiple wafers 50 within the processing chamber 12. When the door panel 90 is in the closed position, it seals the lower end of the lower flange 82. It should be understood that the door panel 90 may be formed of a single type of material, such as metal, or a combination of materials, such as metal and quartz. The door panel 90 may be moved vertically and raised to close the openings of the flange and processing tube 10 by sealing the lower flange 82. The door panel 90 is opened by moving downward relative to the lower flange 82. The upper surface of the door panel 90 supports the base 30, which in turn supports the wafer boat 40. A lift 98 may be provided to move, for example, the door panel 90, the base 30, and the wafer boat 40 to load or unload the wafer boat 40.

[0033] Gas, including inert and reactive precursor gases, can be supplied to the processing chamber 12 from a gas source 95, which may include multiple containers for containing various gases. In some embodiments, the precursor gas may include ammonia (NH3) and / or chloride-containing gases, such as SiH2Cl2, TiCl4, HfCl4, and / or AlCl3. The flow of the precursor gas from the gas source 95 into the processing chamber 12 can be controlled by a controller 94. Gas openings (not shown) may be provided in flanges 80, 82 to supply gas from the gas source 95 to the processing chamber 12 using, for example, a syringe.

[0034] The gas opening in the flange can also be used to remove gas from the processing chamber 12. The reaction precursor gas can produce reaction byproducts, which can cause condensation on cooler parts of the vertical furnace 100, such as flanges 80, 82 and / or door panel 90.

[0035] The temperature of the door panel 90 may be difficult to control. With each unloading of the wafer boat 40, the door panel 90 moves downward away from the hot furnace 100 and cools significantly. After a newly loaded boat 40 is reloaded into the furnace 100, the door panel 90 will be heated by the hot portion of the furnace above it and by heat from the heating flanges 80, 82. The insulation value of the base 30 can be adjusted within certain limits to increase the heat reaching the door panel 90, thereby adequately heating the door panel 90 to prevent condensation.

[0036] Reference Figure 1 In addition to adjusting the insulation value of the base 30 to provide sufficient heat to the door panel 90, or as an alternative, a door panel heater 92 may be provided. The door panel heater 92 is preferably located below the base 30.

[0037] The temperature of the door panel 90 can be monitored in various ways. For example, a temperature sensor 96 is preferably provided to actively monitor and control the door panel temperature. The temperature sensor 96 communicates with the controller 94. After the desired door panel temperature is reached, the controller 94 causes reactant gases to flow from the gas source 95 into the processing chamber 12 to perform various processes, including chemical vapor deposition of films on the substrate.

[0038] The upper and lower flanges 80 and 82 can be equipped with electric heaters 88 to raise the flange temperature and minimize condensation on the flanges. In an exemplary design for a furnace processing 300mm wafers, flanges 80 and 82 can be equipped with more than 20 heaters, each providing a maximum of approximately 100 watts of heat. It should be understood that the number of heaters depends on the flange design, the heater design and power, the thermal insulation of the base 30, and the amount of insulation material disposed on the outside of the tube 10 and flanges 80 and 82. For example, more heaters can be used if the heater power is low, if the base 30 is highly insulated to minimize the heat reaching flanges 80 and 82 from the upper part of the furnace 100, and / or if flanges 80 and 82 lose a significant amount of heat due to the minimal insulation of these flanges. Conversely, fewer heaters can be used if the heater power is higher, if the base 30 does not significantly insulate flanges 80 and 82 from the upper part of the furnace 100, and / or if flanges 80 and 82 are well insulated from heat loss.

[0039] During the unloading of the processed wafer load, the hot wafer 50 and hot wafer boat 40 can pass through flanges 80 and 82. Without precautions, the O-rings in flanges 80 and 82 that contact other surfaces to provide a vacuum seal may overheat. Deterioration of the O-rings undesirably reduces their ability to isolate the atmosphere inside the processing tube 10 from the surrounding environment and may potentially lead to contamination or otherwise adversely affect the processing results. Therefore, a cooling channel 86 can be provided to prevent the O-rings from overheating.

[0040] Channel 86 may be provided with a flowing fluid to remove heat from flanges 80, 82, thereby cooling the O-rings in contact with these flanges. A possible fluid for channel 86 is water. However, water boils at 100°C and has a large cooling capacity, which could cause the flanges to be cooled too much, potentially leading to condensation of reaction byproducts on the generally circular inner surfaces of the openings formed by flanges 80, 82. Designs according to some preferred embodiments avoid these and other disadvantages and allow the use of water cooling. Figure 1 As schematically shown, the water-cooling channel 86 can be configured to not be in close contact with flanges 80 and 82. The cooling channel 86 can... Figure 2 , 3 This is shown in more detail in section 4.

[0041] Reference Figure 2The diagram shows a cross-section of flange 800, having an outer surface 802 and an inner surface 804. The inner surface 804 may be generally circular. It is understood that flange 800 may be, for example... Figure 1 Either the upper or lower flange 80 or 82. For example, flange 800 can be... Figure 1 In the case of the lower flange 82, a heater 88 can be provided ( Figure 1 The heater 812. The flange may be provided with a top surface and a bottom surface, in which a recess 810 may be formed to provide space for an O-ring, allowing the flange 82 to seal adjacent structures. Such structures may be, for example, a door panel 90, an upper flange 80, and / or a pipe 10 ( Figure 1 ).

[0042] Continue to refer to Figure 2 The wall 822 of the housing 821, which contains the coolant fluid, defines a cooling channel 86. The housing 821 may extend partially around the periphery of the flange 800, and the cooling channel 86 may also extend partially around the periphery of the flange 800 to facilitate uniform cooling of the flange. For example, in the illustrated embodiment, the flange 800 is circular in horizontal cross-section, and the housing 821 may be partially annular. The housing 821 may be removable to facilitate furnace maintenance, for example.

[0043] Flange 800 may be provided with space for at least partially or completely accommodating cooling channel 86. For example, housing 821 defining cooling channel 86 may be accommodated in recess 823 defining space in flange 800. Recess 823 may extend partially or completely around flange 800. Housing 821 may extend along recess 823 to allow uniform cooling of flange 800. Recess 823 may be provided in the top, bottom, or outer surface 802 of flange 800. Recess 823 may be larger than housing 821. Therefore, recess 823 (e.g., cooling channel 86) may have an inner wall spaced apart from the outer wall of housing 821, such that open spaces 830, 831, and 832 may exist between housing 821 and flange 800.

[0044] Therefore, the space formed by the recess 823 for accommodating the cooling channel 86 can be larger than the space required for the cooling channel 86 to leave an open space. This open space can be provided with a material having a thermal conductivity between 0.1 and 40 W / m K, preferably between 0.5 and 10 W / m K, and even more preferably between 1 and 6 W / m K. Alternatively or additionally, the wall 822 of the outer shell 821 forming the cooling channel 86 can be made of a similar material having a thermal conductivity between 0.1 and 40 W / m K, preferably between 0.5 and 10 W / m K, and even more preferably between 1 and 6 W / m K. By ensuring that the material having a thermal conductivity between 0.1 and 40 W / m K, preferably between 0.5 and 10 W / m K, and even more preferably between 1 and 6 W / m K, is at least partially between the cooling fluid and the remainder of the flange 800, a suitable coolant fluid for the cooling channel 86 can be water. Water has a high cooling capacity, but by using a material with a thermal conductivity between 0.1 and 40 W / m K, preferably between 0.5 and 10 W / m K, and even more preferably between 1 and 6 W / m K, the flange 800 will not be overcooled. Therefore, the risk of reaction byproducts condensing on the generally circular inner surface of the flange 800 can be minimized. On the other hand, the risk of boiling water in the cooling channel 86 can also be minimized. The material can be applied uniformly in the entire recess 821 around the flange 800 with the same thickness. In this way, the thermal conductivity around the flange 800 is uniform, avoiding cold and hot spots in the flange 800. Advantageously, preventing overcooling in this way is more reliable and simpler than using media with lower cooling capacity (including heated cooling media such as warm or hot water or heated ethylene glycol).

[0045] Figure 2 The arrangement shown allows for customization of the thermal conductivity between flange 800 and cooling channel 86 to accommodate different processing requirements. The dimensions of the housing 821, such as the open spaces 830, 831, and 832 between cooling channel 86 and flange 800, can be varied to alter heat transfer between the cooling channel 86 and flange 800. For example, the dimensions of recess 823 can be increased or decreased, and / or the dimensions of cooling channel 86 can be decreased or increased to decrease or increase the dimensions of the open spaces 830, 831, and 832 between flange 800 and ring 821, thereby decreasing or increasing the thermal conductivity.

[0046] Figure 3This is a schematic cross-sectional view of a cooling channel 86 in a flange 800 according to an embodiment. The cooling channel 86 may have a generally circular cross-section. The cooling channel 86 may be partially or completely contained in a recess 823 defining a space in the flange 800. A portion of the space or recess 823 may contain the cooling channel 86, while another portion may remain open, forming an open space in the recess 823. This open space may be provided with a material having a thermal conductivity between 0.1 and 40 W / m K, preferably between 0.5 and 10 W / m K, and even more preferably between 1 and 6 W / m K. Thus, this material is at least partially disposed between the cooling fluid and the remainder of the flange 800.

[0047] The space or recess 823 may have a generally rectangular cross-section. The space for accommodating the cooling channel 86 may be provided in the recess 823 within the outer surface 802 of the flange 800. The opening of the recess 823 may be slightly smaller than the outer radius of the circular cross-section of the cooling channel 86, such that the cooling channel 86 adjoins the opening of the recess, as shown below. Figure 3 As shown. This helps to position the cooling channel within the recess 823. Alternatively, the opening of the recess may be equal to or greater than the outer radius of the circular cross-section of the cooling channel, such that the cooling channel is fitted into the recess.

[0048] The wall 822 of the cooling channel 86 may include metal. The cooling channel 86 may be at least partially surrounded by a material with a thermal conductivity between 0.1 and 40 W / m K. This thermal conductivity may be lower than the thermal conductivity of the metal of the cooling channel 86.

[0049] The cooling channel 86 may have walls 822 comprising a material with a thermal conductivity between 0.1 and 40 W / m K. The walls 822 may comprise multiple layers, such as a bilayer combining a metal layer with a layer of material having a thermal conductivity between 0.1 and 40 W / m K. This can be easier to manufacture, or even readily available off-the-shelf.

[0050] Materials with thermal conductivity between 0.1 and 40 W / m K can be selected, for example, from the group consisting of lead (35 W / m K), glass (0.8 W / m K), concrete (0.8 W / m K), and polymers such as silicone resin (3 W / m K) and polytetrafluoroethylene (PTFE) (0.2 to 0.6 W / m K). Silicone resins, such as polysiloxanes, are silicon-containing polymers composed of siloxanes (-R2Si-O-SiR2-, where R = organic group). Polytetrafluoroethylene (PTFE) is a fluoropolymer composed of tetrafluoroethylene. Flanges can be made of metal, such as (stainless steel) steel or aluminum.

[0051] Figure 4 This is a schematic top view of the cooling channel according to an embodiment. The cooling channel 86 may be disposed in a recess 823 provided along the periphery of the flange 800, for example in... Figure 1-3 In the flange. The flange 800 may be provided with an opening 841 for access to the interior of the processing pipe 10 during use.

[0052] During heating and cooling, flange 800 may expand and contract due to thermal expansion. The cooling channel, however, maintains a very stable temperature and does not expand or contract significantly. This may result in the cooling channel 86 being pressed more forcefully against flange 800 when the flange is hot. This could alter the thermal conductivity and / or potentially reduce the quality of the material and / or the cooling channel 86, where the thermal conductivity is between 0.1 and 40 W / m K.

[0053] A constant force actuator F, such as spring 840, can be used to apply a constant force to the cooling channel 86. This constant force can cause the cooling channel 86 to press against the flange 800 and / or a material with a thermal conductivity between 0.1 and 40 W / m K with the same force over a wide temperature range and throughout the periphery of the flange 800.

[0054] Preferred embodiments are particularly suitable for chemical reactions involving the combination of chlorinated reactants and ammonia (NH3). Examples of chlorinated reactants are: TiCl4, SiCl2H2, HfCl4, and AlCl3. Although the embodiments were developed in the context of chlorination, it is conceivable that the principles described herein can be advantageously applied in other cases where condensable reaction byproducts are produced, such as in the case of organic reactant materials (e.g., alkoxy metals or alkoxysilanes).

[0055] 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.

[0056] Throughout this specification, references to "an embodiment" or "one 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 one embodiment" or "in one embodiment" appearing in different places throughout this specification do not necessarily refer to the same embodiment. Furthermore, note that specific features, structures, or characteristics of one or more embodiments can be combined in any suitable manner to form new embodiments not explicitly described.

Claims

1. A flange for a processing tube in an apparatus for processing a substrate, the flange having an opening for access to a processing chamber of the processing tube in use, the cooling channel for allowing a cooling fluid to flow through and cool the flange, wherein a material with a thermal conductivity between 0.1 and 40 W / m K is at least partially disposed between the cooling fluid and the flange, wherein the flange has a space for receiving the cooling channel, the cooling channel being partially received within the space. in, The space for accommodating the cooling channel is formed in a recess in the outer surface of the flange. The cooling channel has a generally circular cross-section, the recess has a generally rectangular cross-section, and the opening of the recess is slightly smaller than the outer radius of the circular cross-section of the cooling channel, such that the cooling channel contacts the opening of the recess.

2. The flange according to claim 1, wherein, The material with a thermal conductivity between 0.5 and 10 W / m K is at least partially disposed between the cooling fluid and the flange.

3. The flange according to claim 1, wherein, The material with a thermal conductivity between 1 and 6 W / m K is at least partially disposed between the cooling fluid and the flange.

4. The flange according to claim 1, wherein, The flange has a top surface and a bottom surface, and the top surface and the bottom surface are provided with recesses for O-rings.

5. The flange according to claim 1, wherein, The flange has a generally circular inner surface that forms the opening.

6. The flange according to claim 1, wherein, A portion of the space used to house the cooling aisles remains open, thus creating an open space.

7. The flange according to claim 6, wherein, The open space is provided with a material with a thermal conductivity between 0.1 and 40 W / m K.

8. The flange according to claim 1, wherein, The cooling channel is made of metal and is at least partially surrounded by a material with a lower thermal conductivity than metal.

9. The flange according to claim 1, wherein, The cooling channels are made of a material with a thermal conductivity between 0.1 and 40 W / m K.

10. The flange according to claim 1, wherein, The heater is located in a recess on the outer surface of the flange.

11. The flange according to claim 1, wherein, The flange is provided with a gas opening for supplying or removing gas from the reaction tube.

12. The flange according to claim 1, wherein, The material, at least partially disposed between the cooling fluid and the rest of the flange, is a polymer.

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