Wafer trays, thin film deposition equipment and methods

Abstract

This invention provides a wafer tray, a thin film deposition apparatus, and a thin film deposition method. The wafer tray includes a tray body and an edge ring. The upper surface edge of the tray body has a plurality of first positioning portions. The lower surface edge of the edge ring has a plurality of second positioning portions. The plurality of second positioning portions cooperate with the plurality of first positioning portions to eccentrically mount the edge ring to the upper surface of the tray body, thereby correcting the film thickness at the wafer edge supported by the tray body and surrounded by the edge ring in subsequent thin film deposition processes. This invention can adjust the distance between the edge ring and the wafer edge by setting an edge ring with a fixed eccentric distance from the center of the tray body, thereby adjusting the film thickness at the wafer edge and improving the uniformity of the film deposited on the wafer surface.

Description

Technical Field

[0001] This invention relates to the field of semiconductor device processing, and more particularly to a wafer tray, a thin film deposition apparatus, and a thin film deposition method. Background Technology

[0002] In semiconductor device fabrication, the uniformity and thickness distribution of thin films directly affect the performance and production efficiency of semiconductor devices. During thin film deposition, the film thickness typically exhibits a distribution where the central region is thinner and the edge region is thicker. This uneven thickness is particularly pronounced at the wafer edge, often resulting in significant fluctuations in edge thickness, and even the appearance of marked high and low points. Existing edge ring technology is widely used in thin film deposition processes to modify the film thickness at the wafer edge. However, because the inner diameter center of existing edge rings is concentric with the wafer center, they can only increase or decrease the overall thickness at the wafer edge, failing to precisely control localized fluctuations. Especially when there are large fluctuations in the edge thickness of the wafer, with obvious high and low points, traditional edge rings cannot precisely adjust it, severely impacting the film deposition quality.

[0003] In order to overcome the above-mentioned defects in the existing technology, there is an urgent need in the field for an improved wafer tray to adjust the distance between the edge ring and the wafer edge, thereby adjusting the wafer edge film thickness to improve the uniformity of the film deposited on the wafer surface. Summary of the Invention

[0004] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define 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 descriptions that follow.

[0005] To overcome the aforementioned deficiencies in the prior art, the present invention provides a wafer tray, a thin film deposition apparatus, and a thin film deposition method. By setting an edge ring with a fixed eccentric distance from the center of the tray body, the distance between the edge ring and the wafer edge can be adjusted, thereby adjusting the film thickness at the wafer edge and improving the uniformity of the thin film deposited on the wafer surface.

[0006] Specifically, the wafer tray provided according to the first aspect of the present invention includes a tray body and an edge ring. The edge of the upper surface of the tray body is provided with a plurality of first positioning portions. The edge of the lower surface of the edge ring is provided with a plurality of second positioning portions. The plurality of second positioning portions cooperate with the plurality of first positioning portions to eccentrically mount the edge ring to the upper surface of the tray body, so as to correct the film thickness of the wafer edge supported by the tray body and surrounded by the edge ring in subsequent thin film deposition processes.

[0007] Furthermore, in some embodiments of the present invention, one of the first positioning part and the second positioning part is a positioning hole, and the other is a positioning pin.

[0008] Furthermore, in some embodiments of the present invention, the plurality of first positioning portions and the plurality of second positioning portions are distributed with the same diameter on the edge of the upper surface of the tray body and the edge of the lower surface of the edge ring. The edge ring has a width on its first side that is greater than the width on its opposite second side, such that the center of its inner wall forms an eccentricity with the center of the tray body toward the second side.

[0009] Furthermore, in some embodiments of the present invention, the wafer tray includes a plurality of the edge rings. Each of the edge rings has a different eccentricity and is selectively mounted to the upper surface of the tray body according to the film thickness of the wafer edge.

[0010] Further, in some embodiments of the present invention, the edge of the upper surface of the tray body is provided with two first positioning portions. The edge of the lower surface of the edge ring is provided with three or more second positioning portions. The edge ring is rotated to a corresponding angle according to the film thickness of the wafer edge, and the edge ring is eccentrically mounted to the upper surface of the tray body via two second positioning portions aligned with the two first positioning portions, so as to correct the film thickness of the wafer edge in subsequent thin film deposition processes. Alternatively, the edge of the upper surface of the tray body is provided with three or more first positioning portions. The edge of the lower surface of the edge ring is provided with two second positioning portions. The edge ring is rotated to a corresponding angle according to the film thickness of the wafer edge, and the edge ring is eccentrically mounted to the upper surface of the tray body via two first positioning portions aligned with the two second positioning portions, so as to correct the film thickness of the wafer edge in subsequent thin film deposition processes.

[0011] Furthermore, in some embodiments of the present invention, the tray body is connected to a rotating mechanism for rotating the tray body according to the film thickness distribution of the wafer edge after the edge ring is eccentrically mounted to the upper surface of the tray body, so as to correct the film thickness of the wafer edge in subsequent thin film deposition processes.

[0012] Furthermore, in some embodiments of the present invention, the wafer tray further includes a controller configured to: acquire the actual thin film thickness distribution and the target thin film thickness distribution at the edge of the wafer, and determine the deposition thickness distribution of the thin film deposition process on the edge of the wafer based on the difference between the two; determine the direction in which the maximum value is located based on the deposition thickness distribution; and rotate the tray body to rotate the farthest end of the edge ring to the center of the tray body to the direction in which the maximum value is located, so that the edge of the wafer reaches the target thin film thickness distribution after passing through the thin film deposition process.

[0013] Furthermore, in some embodiments of the present invention, the tray body integrates a heating element for heating the wafer during the thin film deposition process.

[0014] Furthermore, the thin film deposition apparatus described above is provided according to a second aspect of the present invention. The thin film deposition apparatus includes a process chamber. A wafer tray as provided in the first aspect of the present invention is disposed within the process chamber.

[0015] Furthermore, the thin film deposition method provided by the third aspect of the present invention includes the following steps: obtaining an actual thin film thickness distribution at the edge of a wafer and its corresponding target thin film thickness distribution, and determining the deposition thickness distribution of the thin film deposition process at the edge of the wafer based on the difference between the two; determining the direction in which the maximum value is located based on the deposition thickness distribution; rotating the tray body or edge ring of the wafer tray provided by the first aspect of the present invention, rotating the farthest end of the edge ring to the center of the tray body to the direction in which the maximum value is located; and performing a thin film deposition process on the wafer supported by the tray body and surrounded by the edge ring, so that its edge reaches the target thin film thickness distribution. Attached Figure Description

[0016] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0017] Figure 1 A schematic diagram of the structure of a wafer tray provided according to some embodiments of the present invention is shown.

[0018] Figure 2 A schematic diagram of the structure of a wafer tray provided according to some embodiments of the present invention is shown.

[0019] Figure 3 A simplified schematic diagram of the cross-section of the outer and inner diameters of an edge ring provided according to some embodiments of the present invention is shown.

[0020] Figure 4 A schematic diagram of the structure of a tray body provided according to some embodiments of the present invention is shown.

[0021] Figure 5 A schematic diagram of the structure of an edge ring provided according to some embodiments of the present invention is shown.

[0022] Figure 6 A schematic cross-sectional view of the tray body and edge ring provided according to some embodiments of the present invention is shown.

[0023] Figure 7 A schematic cross-sectional view of a wafer tray provided according to some embodiments of the present invention is shown.

[0024] Figure 8 A schematic diagram of the structure of a wafer tray provided according to some embodiments of the present invention is shown.

[0025] Figure 9 A schematic cross-sectional view of a wafer tray provided according to some embodiments of the present invention is shown.

[0026] Figure 10 A schematic flowchart of a thin film deposition method according to some embodiments of the present invention is shown.

[0027] Figure 11 A schematic diagram showing the location of the maximum distance between the wafer edge and the edge ring according to some embodiments of the present invention is shown.

[0028] Figure 12 A schematic diagram showing the location of the minimum distance between the wafer edge and the edge ring according to some embodiments of the present invention is shown.

[0029] Figure 13 A diagram showing the electron density distribution inside a wafer tray, provided according to a reference example, is shown.

[0030] Figure 14 The diagram shows the electron density distribution inside a wafer tray provided by some embodiments of the present invention.

[0031] Figure label:

[0032] 11. Tray body

[0033] 111 First Positioning Department

[0034] 12 Edge rings

[0035] 121 Second Positioning Section

[0036] 13 wafers Detailed Implementation

[0037] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a thorough understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description.

[0038] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0039] Furthermore, the terms "upper," "lower," "left," "right," "top," "bottom," "horizontal," and "vertical" used in the following description should be understood as the orientations shown in the relevant paragraphs and accompanying drawings. These relative terms are for illustrative purposes only and do not imply that the described apparatus must be manufactured or operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0040] It is understood that although terms such as "first," "second," and "third" may be used herein to describe various components, regions, layers, and / or parts, these components, regions, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers, and / or parts. Therefore, the first components, regions, layers, and / or parts discussed below may be referred to as second components, regions, layers, and / or parts without departing from some embodiments of the present invention.

[0041] As mentioned above, existing edge ring technology is widely used in thin film deposition processes to modify the film thickness at the wafer edge. However, because the inner diameter center of existing edge rings is concentric with the wafer center, it can only increase or decrease the film thickness at the wafer edge as a whole, and cannot precisely control local fluctuations in the edge film thickness. Especially when the edge film thickness of the wafer exhibits a large range of fluctuations and obvious high and low points, traditional edge rings cannot precisely adjust it, thus severely affecting the film deposition quality of the wafer.

[0042] To overcome the aforementioned deficiencies in the prior art, the present invention provides a wafer tray, a thin film deposition apparatus, and a thin film deposition method. By setting an edge ring with a fixed eccentric distance from the center of the tray body, the distance between the edge ring and the wafer edge can be adjusted, thereby adjusting the film thickness at the wafer edge and improving the uniformity of the thin film deposited on the wafer surface.

[0043] In a non-limiting embodiment, the thin film deposition apparatus provided in the second aspect of the present invention includes a process chamber. Here, a wafer tray as provided in the first aspect of the present invention is disposed within the process chamber.

[0044] Please refer to the references for further details. Figure 1 and Figure 2 . Figure 1 A schematic diagram of the structure of a wafer tray provided according to some embodiments of the present invention is shown. Figure 2 A schematic diagram of the structure of a wafer tray provided according to some embodiments of the present invention is shown.

[0045] exist Figure 1 and Figure 2 In the illustrated embodiment, the wafer tray provided by the first aspect of the present invention includes a tray body 11 and an edge ring 12. Here, the edge of the upper surface of the tray body 11 is provided with a plurality of first positioning portions 111. The edge of the lower surface of the edge ring 12 is provided with a plurality of second positioning portions 121. Here, the plurality of second positioning portions 121 cooperate with the plurality of first positioning portions 111 to eccentrically mount the edge ring 12 to the upper surface of the tray body 11, so as to correct the film thickness of the edge of the wafer 13 supported by the tray body 11 and surrounded by the edge ring 12 in subsequent thin film deposition processes.

[0046] Specifically, the aforementioned edge ring 12 can change the airflow and temperature field at the edge of the wafer 13 so that the deposition conditions in the edge region of the wafer 13 are similar to those in the center region, thereby avoiding the phenomenon of excessively thick or thin edge film.

[0047] Furthermore, in Figure 1 and Figure 2 In the embodiment shown, one of the first positioning part 111 and the second positioning part 121 is a positioning hole, and the other is a positioning pin.

[0048] Please refer to further information. Figure 3 . Figure 3 A simplified schematic diagram of the cross-section of the outer and inner diameters of an edge ring provided according to some embodiments of the present invention is shown.

[0049] like Figure 3As shown, a plurality of first positioning portions 111 and a plurality of second positioning portions 121 are distributed with the same diameter on the edge of the upper surface of the tray body 11 and the edge of the lower surface of the edge ring 12. Here, the width of the edge ring 12 on its first side is greater than the width of its opposite second side, so that the center of its inner wall forms an eccentricity e with the center of the tray body 11 toward the second side.

[0050] Furthermore, in some preferred embodiments, the wafer tray provided in the first aspect of the present invention includes a plurality of edge rings 12. Here, each edge ring 12 has a different eccentricity e (e.g., 0.1 to 10 mm) and is selectively mounted to the upper surface of the tray body 11 according to the film thickness at the edge of the wafer 13.

[0051] Please refer to the reference. Figures 4-7 . Figure 4 A schematic diagram of the structure of a tray body provided according to some embodiments of the present invention is shown. Figure 5 A schematic diagram of the structure of an edge ring provided according to some embodiments of the present invention is shown. Figure 6 A schematic cross-sectional view of the tray body and edge ring provided according to some embodiments of the present invention is shown. Figure 7 A schematic cross-sectional view of a wafer tray provided according to some embodiments of the present invention is shown.

[0052] exist Figure 4 In the illustrated embodiment, two first positioning portions 111 are provided on the edge of the upper surface of the tray body 11. Figure 5 In the illustrated embodiment, the lower surface of the edge ring 12 is provided with three or more (e.g., 12) second positioning portions 121. Figure 6 and Figure 7 In the illustrated embodiment, the edge ring 12 is rotated to a corresponding angle according to the film thickness distribution of the wafer 13 edge, and the edge ring 12 is eccentrically mounted to the upper surface of the tray body 11 via two second positioning parts 121 aligned with two first positioning parts 111, so as to correct the film thickness of the wafer 13 edge in subsequent thin film deposition processes.

[0053] Please refer to the reference. Figure 8 and Figure 9 . Figure 8 A schematic diagram of the structure of a wafer tray provided according to some embodiments of the present invention is shown. Figure 9 A schematic cross-sectional view of a wafer tray provided according to some embodiments of the present invention is shown.

[0054] exist Figure 8 In the illustrated embodiment, the edge of the upper surface of the tray body 11 is provided with three or more (e.g., 12) first positioning portions 111, and the edge of the lower surface of the edge ring 12 is provided with two second positioning portions 121. Figure 9 In the illustrated embodiment, the edge ring 12 is rotated to a corresponding angle according to the film thickness distribution of the wafer 13 edge, and the edge ring 12 is eccentrically mounted to the upper surface of the tray body 11 via two first positioning parts 111 aligned with two second positioning parts 121, so as to correct the film thickness of the wafer 13 edge in subsequent thin film deposition processes.

[0055] Furthermore, in some preferred embodiments, the tray body 11 is connected to a rotating mechanism for rotating the tray body 11 according to the thin film thickness distribution at the edge of the wafer 13 after the edge ring 12 is eccentrically mounted to the upper surface of the tray body 11, so as to correct the thin film thickness at the edge of the wafer 13 in subsequent thin film deposition processes.

[0056] Furthermore, in some optional embodiments, the wafer tray provided in the first aspect of the present invention also includes a controller. Here, the controller can be connected to the aforementioned rotating mechanism to implement the thin film deposition method provided in the third aspect of the present invention.

[0057] In addition, in some alternative embodiments, the tray body 11 is integrated with a heating element for heating the wafer 13 during the thin film deposition process.

[0058] The working principle of the above-described thin film deposition apparatus will be described below with reference to some embodiments of thin film deposition methods. Those skilled in the art will understand that these embodiments of thin film deposition methods are merely non-limiting implementations provided by the present invention, intended to clearly demonstrate the main concepts of the invention and provide specific solutions convenient for public implementation, rather than limiting all functions or operating methods of the thin film deposition apparatus. Similarly, the thin film deposition apparatus is also merely a non-limiting implementation of the present invention and does not constitute a limitation on the subject or order of execution of the steps in these thin film deposition methods.

[0059] Please refer to the reference. Figures 10-12 . Figure 10 A schematic flowchart of a thin film deposition method according to some embodiments of the present invention is shown. Figure 11 A schematic diagram showing the location of the maximum distance between the wafer edge and the edge ring according to some embodiments of the present invention is shown. Figure 12 A schematic diagram showing the location of the minimum distance between the wafer edge and the edge ring according to some embodiments of the present invention is shown.

[0060] like Figure 10 As shown, the thin film deposition apparatus provided by the second aspect of the present invention can first obtain the actual thin film thickness distribution at the edge of a wafer 13 and its corresponding target thin film thickness distribution, and determine the deposition thickness distribution at the edge of the wafer 13 by the thin film deposition process based on the difference between the two.

[0061] Specifically, the above-mentioned thin film deposition process includes product correction process scenarios where the actual thin film thickness distribution is uneven, but the target thin film thickness distribution is uniform; customized process scenarios where the actual thin film thickness distribution is uniform, but the target thin film thickness distribution is uneven; and error compensation process scenarios where both the actual and target thin film thickness distributions are uniform, but the thin film deposition rate is uneven.

[0062] Then, the thin film deposition equipment can determine the direction of the maximum value based on the deposition thickness distribution.

[0063] Subsequently, the thin film deposition apparatus can rotate the tray body 11 or edge ring 12 of the wafer tray as provided in the first aspect of the invention, rotating the edge ring 12 to the farthest point from the center of the tray body 11 to the direction where the maximum value is located.

[0064] Specifically, such as Figure 11 As shown, the maximum distance between the edge of wafer 13 and the edge ring 12 is d1. Figure 12 As shown, the minimum distance between the edge of wafer 13 and edge ring 12 is d2.

[0065] Subsequently, the thin film deposition equipment can perform a thin film deposition process on the wafer 13 supported by the tray body 11 and surrounded by the edge ring 12, so that its edge achieves the target thin film thickness distribution.

[0066] Please refer to the reference. Figure 13 and Figure 14 . Figure 13 A diagram showing the electron density distribution inside a wafer tray, provided according to a reference example, is shown. Figure 14 The diagram shows the electron density distribution inside a wafer tray provided by some embodiments of the present invention.

[0067] Compared to Figure 14 The distance between the edge ring and the wafer shown in this invention is... Figure 13 The edge ring shown is closer to the wafer, and the red area of ​​electron density is larger, resulting in a higher electron density and thus a higher deposition rate and a thicker film. Therefore, the wafer tray provided in the first aspect of the present invention can improve the uniformity of the film deposited on the surface of wafer 13 by eccentrically positioning the edge ring 12 relative to the tray body 11 and adjusting the film thickness at the edge of wafer 13 according to the film thickness distribution on the surface of wafer 13 during the film deposition process.

[0068] In summary, the wafer tray, thin film deposition equipment, and thin film deposition method provided by the present invention can all improve the uniformity of the thin film deposited on the wafer surface by setting an edge ring with a fixed eccentric distance from the center of the tray body to adjust the distance between the edge ring and the wafer edge, thereby adjusting the film thickness at the wafer edge.

[0069] Although the methods described above are illustrated and depicted as a series of actions for the sake of simplicity, it should be understood and appreciated that these methods are not limited by the order of the actions, as some actions may occur in a different order and / or concurrently with other actions from the illustrations and descriptions herein or not illustrated and described herein but which may be understood by those skilled in the art, according to one or more embodiments.

[0070] Although the controller described in the above embodiments can be implemented through a combination of software and hardware, it is understood that the controller can also be implemented in software or hardware. For hardware implementation, the controller can be implemented using one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, other electronic devices for performing the above functions, or a selection of combinations of the above devices. For software implementation, the controller can be implemented using independent software modules such as procedures and functions running on a general-purpose chip, each module performing one or more functions and operations described herein.

[0071] The prior description of this disclosure is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not intended to be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wafer tray, characterized in that, include: The pallet body has two first positioning parts on the edge of its upper surface; An edge ring has three or more second positioning portions on its lower surface edge. The edge ring is rotated to a corresponding angle according to the film thickness of the wafer edge, and the edge ring is eccentrically mounted to the upper surface of the tray body via two second positioning portions aligned with two first positioning portions, so as to correct the film thickness of the wafer edge in subsequent thin film deposition processes.

2. The wafer tray as described in claim 1, characterized in that, One of the first positioning part and the second positioning part is a positioning hole, and the other is a positioning pin.

3. The wafer tray as described in claim 1, characterized in that, The two first positioning parts and the three or more second positioning parts are respectively distributed with the same diameter on the edge of the upper surface of the tray body and the edge of the lower surface of the edge ring, wherein... The width of the edge ring on its first side is greater than the width on its opposite second side, such that the center of its inner wall forms an eccentricity with the center of the tray body toward the second side.

4. The wafer tray as described in claim 3, characterized in that, The wafer tray includes a plurality of edge rings, each edge ring having a different eccentricity, and is selectively mounted to the upper surface of the tray body according to the film thickness of the wafer edge.

5. The wafer tray as described in claim 1, characterized in that, The tray body is connected to a rotating mechanism for rotating the tray body according to the film thickness distribution at the wafer edge after the edge ring is eccentrically mounted to the upper surface of the tray body, so as to correct the film thickness at the wafer edge in subsequent thin film deposition processes.

6. The wafer tray as described in claim 5, characterized in that, The wafer tray also includes a controller configured to: The actual thin film thickness distribution and the target thin film thickness distribution at the edge of the wafer are obtained, and the deposition thickness distribution of the thin film deposition process at the edge of the wafer is determined based on the difference between the two. Based on the deposition thickness distribution, determine the direction of the maximum value; and Rotate the tray body, and rotate the farthest end of the edge ring to the center of the tray body to the direction of the maximum value, so that the wafer edge achieves the target film thickness distribution after passing through the thin film deposition process.

7. The wafer tray as described in claim 1, characterized in that, The tray body integrates a heating element for heating the wafer during the thin film deposition process.

8. A wafer tray, characterized in that, include: The pallet body has three or more first positioning parts on the edge of its upper surface; An edge ring has two second positioning portions on its lower surface edge. The edge ring is rotated to a corresponding angle according to the film thickness of the wafer edge, and is eccentrically mounted to the upper surface of the tray body via two first positioning portions aligned with the two second positioning portions, so as to correct the film thickness of the wafer edge in subsequent thin film deposition processes.

9. A thin film deposition apparatus, characterized in that, The thin film deposition apparatus includes a process chamber, wherein a wafer tray as described in any one of claims 1 to 8 is disposed in the process chamber.

10. A thin film deposition method, characterized in that, Includes the following steps: Obtain the actual thin film thickness distribution at the edge of a wafer and its corresponding target thin film thickness distribution, and determine the deposition thickness distribution of the thin film deposition process at the edge of the wafer based on the difference between the two. Based on the deposition thickness distribution, determine the direction of the maximum value; Rotate the wafer tray body or edge ring as described in any one of claims 1 to 8, rotating the farthest end of the edge ring from the center of the tray body to the direction where the maximum value is located; and A thin film deposition process is performed on the wafer supported by the tray body and surrounded by the edge ring so that its edge achieves the target thin film thickness distribution.

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