Process chamber and thin film deposition method

Abstract

The present application provides a process chamber and a thin film deposition method. The process chamber includes a heating plate, a shower cover, an exhaust port, a ring-shaped platform, and a lifting device. The heating plate is used to carry and heat a wafer to be processed. The shower cover is arranged at the upper part of the process chamber and is used to spray reactants onto the heating plate. The exhaust port is arranged at the lower part of the process chamber and is used to exhaust exhaust gas from the process chamber. The outer ring-shaped platform of the ring-shaped platform surrounds the edge of the heating plate. The first height of the outer ring-shaped platform is greater than the second height of the edge of the heating plate. The lifting device is used to drive the ring-shaped platform to lift and change the distance between the outer ring-shaped platform and the shower cover, so as to adjust the fluid distribution on the exhaust path of the exhaust port. The present application can decouple the process height and the exhaust path, expand the process window, and improve the stability of the in-cavity atmosphere environment, thereby improving the stability, repeatability and film uniformity of the process.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor processing, and in particular to a process chamber and a thin film deposition method. BACKGROUND

[0002] In order to meet the high aspect ratio requirements of special components such as DRAM, 3D NAND and advanced node logic devices, a special buffer tank is often provided on the reaction source and its displacement gas channel. The reaction gas is pre-accumulated in the buffer tank before entering the process chamber, so as to pre-increase the reaction gas pressure in the buffer tank, and then optimize the step coverage problem in the high aspect ratio structure in the process. Therefore, under the premise of high inlet gas pressure, the stability of the gas flow and the stability of the atmosphere environment in the process chamber are very important, and the uniformity and efficiency of the pumping are required to be higher.

[0003] In the atomic layer deposition process, the uniformity of the thin film is very sensitive to the atmosphere environment in the process chamber. In the prior art, the process chamber is provided with pumping channels on both sides in the side pumping mode equipment, and finally the pumping channels on both sides are connected to the pumping port and the pumping main pipeline. However, due to the longer path on the side far away from the pumping port, the pumping efficiency on the left and right sides of the chamber is uneven, which will cause the problem of poor thin film uniformity, especially the thickness bias. In addition, the prior art cannot independently adjust the pumping efficiency, and can only change the pumping efficiency by adjusting the height of the heating disc, which will link the process height and the pumping efficiency, change the pumping efficiency and affect the process height, so that the process window is small, which is not conducive to the stable progress of the thin film deposition process.

[0004] In order to overcome the above-mentioned defects existing in the prior art, the present application provides a thin film deposition technology for decoupling the process height and the pumping path, expanding the process window, and improving the stability of the atmosphere environment in the chamber, thereby improving the stability, repeatability and thin film uniformity of the process. SUMMARY

[0005] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0006] In order to overcome the above-mentioned defects existing in the prior art, the present application provides a process chamber and a thin film deposition method, which can realize decoupling of the process height and the pumping path by setting a liftable ring-shaped platform, expand the process window, and improve the stability of the atmosphere environment in the chamber, thereby improving the stability, repeatability and thin film uniformity of the process.

[0007] Specifically, the process chamber according to the first aspect of the present application comprises a heating plate, a shower head, an exhaust port, a ring-shaped platform, and a lifting device. The heating plate is configured to support and heat a wafer to be processed. The shower head is disposed at an upper portion of the process chamber and configured to spray reactants onto the heating plate. The exhaust port is disposed at a lower portion of the process chamber and configured to exhaust exhaust gas from the process chamber. The ring-shaped platform comprises an outer ring-shaped platform surrounding an edge of the heating plate. A first height of the outer ring-shaped platform is greater than a second height of the edge of the heating plate. The lifting device is configured to drive the ring-shaped platform to move up and down, to change a distance between the outer ring-shaped platform and the shower head, and to adjust a fluid distribution along an exhaust path of the exhaust port.

[0008] Further, in some embodiments of the present application, the lifting device is configured to lower the ring-shaped platform to decrease a first exhaust rate of the edge of the wafer to be close to or equal to a second exhaust rate of a center of the wafer. Alternatively, the lifting device is configured to raise the ring-shaped platform to increase the exhaust rate of the edge of the wafer to be greater than the second exhaust rate of the center of the wafer.

[0009] Further, in some embodiments of the present application, the exhaust port is disposed at a bottom of the process chamber. The first height of the outer ring-shaped platform in each direction is equal. Alternatively, the exhaust port is disposed at a side of the process chamber. The first height of the outer ring-shaped platform at a first side close to the exhaust port is greater than a third height of the outer ring-shaped platform at a second side opposite to the first side. The third height is also greater than the second height of the edge of the heating plate.

[0010] Further, in some embodiments of the present application, the outer ring-shaped platform comprises a stepped structure or a beveled structure. A ratio of the first height of the outer ring-shaped platform at the first side close to the exhaust port to the third height of the outer ring-shaped platform at the second side away from the exhaust port is between 1.1 and 1.8.

[0011] Further, in some embodiments of the present application, at least one reactant source is further included. The at least one reactant source is connected to the shower head via at least one first buffer tank. The at least one reactant source is configured to uniformly spray at least one gaseous reactant onto the heating plate to perform a thin film deposition process on the wafer.

[0012] Further, in some embodiments of the present application, the at least one reactant source comprises a gaseous reactant source and / or a liquid reactant source. The gaseous reactant source is configured to provide a gaseous reactant to the process chamber. The liquid reactant source is configured to provide a volatile liquid reactant carried by a carrier gas to the process chamber.

[0013] Further, in some embodiments of the present application, at least one carrier gas source is further included. The at least one carrier gas source is connected to the shower cover via a delivery line of the liquid reactant source for providing the carrier gas to the delivery line to carry the vaporized liquid reactant to the process chamber.

[0014] Further, in some embodiments of the present application, at least one purge gas source is further included. The at least one purge gas source is connected to the shower cover via at least one second buffer tank for uniformly spraying purge gas on the heating disk to clean the process chamber.

[0015] Further, in some embodiments of the present application, a vacuum pump is further included. The vacuum pump is connected to the exhaust port for exhausting the exhaust gas from the process chamber via the exhaust port.

[0016] In addition, the above thin film deposition method according to the second aspect of the present application uses the process chamber according to the first aspect of the present application to deposit thin films on wafers. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above features and advantages of the present application will be better understood through reading the detailed description of embodiments of the present application in conjunction with the following drawings, in which: in the drawings, components are not necessarily drawn to scale, and components of similar or identical function or features can have the same or similar reference label.

[0018] Figure 1 A structural schematic diagram of a process chamber according to some embodiments is shown.

[0019] Figure 2A A top view schematic diagram of a ring-type platform according to some embodiments is shown.

[0020] Figure 2B A cross-sectional schematic diagram of a ring-type platform according to some embodiments is shown.

[0021] Figure 3 A structural schematic diagram of a process chamber according to some embodiments is shown.

[0022] Figure 4A A top view schematic diagram of a ring-type platform according to some embodiments is shown.

[0023] Figure 4B A cross-sectional schematic diagram of a ring-type platform according to some embodiments is shown.

[0024] Figure 5A A top view schematic diagram of a ring-type platform according to some embodiments is shown.

[0025] Figure 5BA cross-sectional schematic view of a ring-type platform is shown.

[0026] Reference signs:

[0027] 11 heating disc

[0028] 12 shower cover

[0029] 13 air extraction port

[0030] 14 ring-type platform

[0031] 141 outer ring-type platform

[0032] 15 lifting device

[0033] 161 reaction source

[0034] 162 first buffer tank

[0035] 17 carrier gas source

[0036] 181 purge gas source

[0037] 182 second buffer tank

[0038] 19 vacuum pump DETAILED DESCRIPTION

[0039] The present application is described in detail by specific embodiments, and other advantages and effects of the present application can be easily understood by those skilled in the art from the content disclosed in the description. Although the description of the present application will be introduced in combination with the preferred embodiments, it does not mean that the features of the present application are limited to the embodiments. On the contrary, the purpose of introducing the present application in combination with the embodiments is to cover other options or modifications that can be extended based on the claims of the present application. In order to provide a deep understanding of the present application, many specific details will be included in the following description. The present application can also be implemented without using these details. In addition, in order to avoid confusion or obscure the focus of the present application, some specific details will be omitted in the description.

[0040] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0041] In addition, "upper", "lower", "left", "right", "top", "bottom", "horizontal", "vertical" used in the following description and shown in the drawings should be understood as the orientation shown in the drawing and relative to the present disclosure. These relative terms are for convenience of description only and do not require that the apparatus be made or operated in a particular orientation unless explicitly stated otherwise. Thus, the application should not be construed to be limited to the particular embodiments described.

[0042] It will be understood that, although the terms "first", "second", "third", etc. can be used herein to describe various components, regions, layers and / or sections, these components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one component, region, layer or section from another. Thus, a first component, region, layer or section discussed below could be termed a second component, region, layer or section without departing from the scope of the present disclosure.

[0043] As described above, in the prior art, the process chamber in the side extraction mode is provided with an extraction channel on both sides, which is finally collected on one side and connected to the extraction port and the main extraction pipeline. However, due to the longer path on the side away from the extraction port, the extraction efficiency of the left and right sides in the chamber is uneven, which can cause poor film uniformity, especially the thickness deviation. In addition, the prior art cannot independently adjust the extraction efficiency, and can only change the extraction efficiency by adjusting the height of the heating disc, which can link the process height and the extraction efficiency, change the extraction efficiency and affect the process height, so as to reduce the process window and affect the stable film deposition process.

[0044] In order to overcome the above-mentioned defects of the prior art, the present application provides a process chamber and a film deposition method, which can realize the decoupling of the process height and the extraction path by setting a liftable ring-shaped platform, so as to expand the process window and improve the stability of the atmosphere environment in the chamber, thereby improving the stability, repeatability and film uniformity of the process.

[0045] In some non-limiting embodiments, the film deposition method provided by the second aspect of the present application can be implemented based on the process chamber provided by the first aspect of the present application.

[0046] For details, please refer to Figure 1 , Figure 2A and Figure 2B , Figure 1 Fig. 1 shows a structural schematic diagram of a process chamber according to some embodiments, Figure 2A Fig. 2 shows a top view schematic diagram of a ring-shaped platform according to some embodiments, Figure 2B Fig. 3 shows a cross-sectional schematic diagram of a ring-shaped platform according to some embodiments.

[0047] In Figure 1 , Figure 2Aand Figure 2B In the illustrated embodiment, the process chamber provided by the first aspect of the present invention includes a heating plate 11, a spray cover 12, an exhaust port 13, an annular platform 14, and a lifting device 15.

[0048] Specifically, the heating plate 11 is used to hold and heat the wafer to be processed. The spray cover 12 is located at the upper part of the process chamber and is used to spray the reactants onto the heating plate 11. The exhaust port 13 is located at the lower part of the process chamber and is used to extract exhaust gas from the process chamber.

[0049] The annular platform 14 includes a recessed inner annular platform and an outer annular platform 141 surrounding the edge of the inner annular platform. Here, the outer annular platform 141 surrounds the edge of the heating plate 11, and its first height is greater than the second height of the edge of the heating plate 11.

[0050] The lifting device 15 can be a lifting motor and a lead screw. The first end of the lead screw is connected to the rotating end of the lifting motor, and the second end is connected to the bottom of the inner ring platform of the ring platform 14. It is used to convert the rotation output of the lifting motor into the translational amount of lifting to drive the ring platform 14 to lift and lower, change the distance between the outer ring platform 141 and the spray cover 12, and adjust the fluid distribution on the air extraction path of the air extraction port 13.

[0051] Specifically, in some embodiments, the lifting device 15 can lower the annular platform 14 and increase the distance between the outer annular platform 141 and the spray cover 12 to reduce the first pumping rate at the wafer edge and make it close to or equal to the second pumping rate at the wafer center, thereby reducing the film thickness at the wafer edge.

[0052] Conversely, in other embodiments, the lifting device 15 may also raise the annular platform 14 and reduce the distance between the outer annular platform 141 and the spray cover 12 to increase the first pumping rate at the wafer edge and make it greater than and farther away from the second pumping rate at the wafer center, thereby increasing the film thickness at the wafer edge.

[0053] Therefore, the lifting device 15 can actively adjust the first pumping rate at the wafer edge by lowering or raising the annular platform 14, thereby maintaining the process height of the heating plate 11 and stably and accurately adjusting the film thickness at the wafer edge to improve the uniformity of the film.

[0054] Furthermore, such as Figure 2B As shown, the air extraction port 13 can be located at the bottom of the process chamber to uniformly extract air from multiple directions of the outer ring platform 141. In this case, the first height of the outer ring platform 141 in each direction can be equal.

[0055] However, those skilled in the art can understand that the above embodiment of setting the exhaust port 13 at the bottom of the process chamber to uniformly exhaust gas from all directions is only a non-limiting embodiment provided by the present application, which is intended to clearly show the main concept of the present application and provide some specific solutions for the public to implement, rather than to limit the protection scope of the present application.

[0056] Alternatively, in other embodiments, the exhaust port 13 can also be eccentrically arranged at one side of the process chamber. Correspondingly, the first height of the outer ring platform 141 near the first side of the exhaust port 13 can be greater than the third height thereof near the second side opposite to the first side, so as to increase the gas flow resistance near the first side of the exhaust port 13 to achieve uniform gas exhaust from all directions.

[0057] For more details, please refer to Figure 3 , Figure 4A , Figure 4B , Figure 5A and Figure 5B . Figure 3 Fig. 1 shows a structural schematic diagram of a process chamber according to some embodiments, Figure 4A Fig. 2 shows a top view schematic diagram of a ring platform according to some embodiments, Figure 4B Fig. 3 shows a sectional view schematic diagram of a ring platform according to some embodiments. Figure 5A Fig. 4 shows a top view schematic diagram of a ring platform according to some embodiments, Figure 5B Fig. 5 shows a sectional view schematic diagram of a ring platform according to some embodiments.

[0058] In the embodiment shown in Figure 3 , the exhaust port 13 can be arranged at the right side of the process chamber. Correspondingly, the first height of the outer ring platform 141 near the right side of the exhaust port 13 can be greater than the third height thereof near the left side opposite to the right side, and the third height is still greater than the second height of the edge of the heating disc 11 to determine the gas flow resistance in the corresponding direction.

[0059] Further, as shown in Figures 4A-4B and Figures 5A-5B , the outer ring platform 141 can adopt a stepped structure or a bevelled structure, and the ratio of the first height near the first side of the exhaust port 13 to the third height near the second side away from the exhaust port 13 is between 1.1 and 1.8, so as to adjust the gas flow resistance in all directions and achieve uniform gas exhaust from all directions.

[0060] In this way, the ring platform 14 can compensate the problem of non-uniform gas exhaust caused by the asymmetry of the exhaust path, and further optimize the gas flow uniformity in the process chamber with the exhaust port 13 arranged at the side.

[0061] In addition, please continue to refer to Figure 1In some embodiments, the process chamber provided by the first aspect of the present application can further optionally comprise at least one reaction source 161. The at least one reaction source 161 is connected to the showerhead 12 via at least one first buffer tank 162 for uniformly spraying at least one gaseous reactant onto the heated disk 11 to perform a thin film deposition process on the wafer.

[0062] Further, the at least one reaction source 161 can comprise a gaseous reaction source and / or a liquid reaction source. The gaseous reaction source 161 is used to provide a reaction gas such as NH3to the process chamber. The liquid reaction source is used to provide a liquid reactant such as volatilized TiCl4carried by a carrier gas to the process chamber.

[0063] Still further, in some embodiments, the process chamber provided by the first aspect of the present application can further comprise at least one carrier gas source 17. The at least one carrier gas source 17 is connected to the showerhead 12 via a delivery line of the liquid reaction source for providing a carrier gas to the delivery line to carry the volatilized liquid reactant to the process chamber.

[0064] In addition, in some embodiments, the process chamber provided by the first aspect of the present application can further optionally comprise at least one purge gas source 181. The at least one purge gas source 181 is connected to the showerhead 12 via at least one second buffer tank 182 for uniformly spraying a purge gas onto the heated disk 11 to clean the process chamber.

[0065] In addition, in some embodiments, the process chamber provided by the first aspect of the present application can further optionally comprise a vacuum pump 19. The vacuum pump 19 is connected to the exhaust port 13 for evacuating exhaust gas from the process chamber via the exhaust port 13.

[0066] In summary, the process chamber and the thin film deposition method provided by the present application can achieve decoupling of the process height and the exhaust path by providing a liftable ring-type platform to expand the process window and to improve the stability of the atmosphere environment in the chamber, thereby improving the stability, repeatability and uniformity of the thin film.

[0067] Although the methods are illustrated and described as a series of acts, it will be appreciated that the methods are not limited by the order of acts, as some acts can, in accordance with one or more embodiments, occur simultaneously or in different order than shown and described herein, or can be omitted entirely, depending on the circumstances. Accordingly, not all steps within each method need take place, or the method need take place in the order illustrated herein.

[0068] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A process chamber, comprising: The process chamber comprises: a heating plate for carrying and heating a wafer to be processed; a shower cover disposed at an upper portion of the process chamber for spraying reactants onto the heating plate; an exhaust port disposed at a side of a lower portion of the process chamber for exhausting exhaust gas from the process chamber; a ring-shaped platform, an outer ring-shaped platform of which surrounds an edge of the heating plate, wherein a first height of the outer ring-shaped platform at a first side close to the exhaust port is greater than a third height of the outer ring-shaped platform at a second side opposite to the first side, and the third height is also greater than a second height of the edge of the heating plate; and a lifting device for driving the ring-shaped platform to move up and down to change a distance between the outer ring-shaped platform and the shower cover to adjust a fluid distribution on an exhaust path of the exhaust port. The lifting device lowers the ring-shaped platform to lower a first exhaust rate of the edge of the wafer to be close to or equal to a second exhaust rate of a center of the wafer, or 2. The process chamber of claim 1, wherein, The lifting device raises the ring-shaped platform to raise the exhaust rate of the edge of the wafer to be greater than the second exhaust rate of the center of the wafer. The outer ring-shaped platform has a stepped structure or a bevelled structure, and a ratio between the first height at the first side close to the exhaust port and the third height at the second side away from the exhaust port is between 1.1 and 1.

8.

3. The process chamber of claim 1, wherein, The process chamber further comprises:

4. The process chamber of claim 1, wherein, at least one reactant source connected to the shower cover via at least one first buffer tank for spraying at least one gaseous reactant onto the heating plate uniformly to perform a thin film deposition process on the wafer. The at least one reactant source comprises:

5. The process chamber of claim 4, wherein, a reactant gas source for providing a reactant gas to the process chamber; and / or a liquid reactant source for providing a volatile liquid reactant carried by a carrier gas to the process chamber. The process chamber further comprises:

6. The process chamber of claim 5, wherein, at least one carrier gas source connected to the shower cover via a delivery pipeline of the liquid reactant source for providing the carrier gas to the delivery pipeline to carry the volatile liquid reactant to flow to the process chamber. The process chamber further comprises:

7. The process chamber of claim 4, wherein, at least one purge gas source connected to the shower cover via at least one second buffer tank for spraying a purge gas onto the heating plate uniformly to clean the process chamber. The process chamber further comprises:

8. The process chamber of claim 1, wherein, a vacuum pump connected to the exhaust port for exhausting the exhaust gas from the process chamber via the exhaust port. A thin film deposition process is performed on a wafer in the process chamber according to any one of claims 1 to 8.

9. A thin film deposition method, characterized by, ​

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