Wafer tray and thin film deposition device

Abstract

The present invention provides a wafer tray and a thin film deposition device. The wafer tray comprises: a planar substrate disposed on the upper surface of the wafer tray, having a first air extraction hole and a groove communicating with the first air extraction hole, configured to vacuum-adsorb a wafer positioned on the planar substrate under high pressure conditions to suppress the formation of a thin film on the back surface; and an electrode mesh disposed beneath the planar substrate, configured to electrostatically adsorb the wafer under low pressure conditions to suppress and / or eliminate warping of the wafer.

Description

Technical Field

[0001] The present invention relates to the technical field of thin film deposition, and in particular to a wafer tray and a thin film deposition device. Background Art

[0002] With the advancement of semiconductor technology, the density of memory in semiconductor devices continues to increase, and the curvature of wafers in multi-stacked structures will also increase. At the same time, due to process requirements, there is also a need to frequently switch between high-pressure operating conditions (for example, pressure greater than or equal to 200 Torr) and low-pressure operating conditions.

[0003] Existing wafer trays include electrostatic adsorption wafer trays and vacuum adsorption wafer trays. However, when frequently switching between high-pressure and low-pressure working conditions, if an electrostatic adsorption wafer tray is used, reactive gas will be present in the gaps between the bumps of the wafer tray under high-pressure working conditions, causing film formation on the back of the wafer, thus failing to meet the quality requirements of thin film deposition. If a vacuum adsorption wafer tray is used, the vacuum adsorption capacity will be insufficient under low-pressure working conditions, making it impossible to eliminate wafer warping. Therefore, wafer trays that only have electrostatic adsorption or vacuum adsorption methods can no longer meet the working conditions required for frequent switching between high-pressure and low-pressure working conditions.

[0004] In order to overcome the above-mentioned defects of the prior art, the art urgently needs a wafer tray that can simultaneously meet the adsorption requirements of high-pressure and low-pressure conditions, thereby suppressing the formation of a thin film on the back of the wafer under high-pressure conditions and effectively suppressing and / or eliminating the warping of the wafer under low-pressure conditions. Summary of the Invention

[0005] The following is a brief summary of one or more aspects to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceivable aspects and is neither intended to identify key or critical 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 description that will be provided later.

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides a wafer tray and a thin film deposition device, which are used to simultaneously meet the adsorption requirements of high-pressure conditions and low-pressure conditions, thereby suppressing the formation of a thin film on the back of the wafer under high-pressure conditions and effectively suppressing and / or eliminating the warping of the wafer under low-pressure conditions.

[0007] Specifically, the wafer tray provided according to the first aspect of the present invention includes: a planar substrate, arranged on the upper surface of the wafer tray, provided with a first exhaust hole and a groove connected to the first exhaust hole, for vacuum adsorbing the wafer located on the planar substrate under high pressure conditions to inhibit the formation of a thin film on the back side; and an electrode network, arranged under the planar substrate, for electrostatically adsorbing the wafer under low pressure conditions to inhibit and / or eliminate warping of the wafer.

[0008] Furthermore, in some embodiments of the present invention, the electrode network includes multiple regions, wherein at least one first region is loaded with a positive voltage, and the remaining at least one second region is loaded with a negative voltage, so as to perform bipolar electrostatic adsorption on the wafer.

[0009] Furthermore, in some embodiments of the present invention, a vertical projection of the electrode mesh covers the wafer, and the at least one first region and the at least one second region maintain axial symmetry to provide uniform electrostatic adsorption force to each position of the wafer.

[0010] Furthermore, in some embodiments of the present invention, the electrode mesh is provided with 2N+1 ejector vias and one second exhaust hole. The second exhaust hole is connected to the first exhaust hole, and is used to form a vacuum negative pressure on the back side of the wafer via the first exhaust hole and the groove to vacuum adsorb the wafer. The ejector via and the second exhaust hole have the same area, N+1 ejector vias are provided in the at least one first region, and the second exhaust hole and N ejector vias are provided in the at least one second region, so as to provide uniform electrostatic adsorption force to each position of the wafer.

[0011] Furthermore, in some embodiments of the present invention, the upper surface of the planar substrate is provided with a plurality of grooves, wherein the grooves intersect with each other to form a plurality of planar bumps that contact the wafer. The wafer tray provides a vacuum suction force corresponding to the negative vacuum pressure therein to the wafer via the plurality of grooves, and provides an electrostatic suction force corresponding to the total area of the wafer via the plurality of planar bumps.

[0012] Furthermore, in some embodiments of the present invention, the planar protrusion is a parallelogram with a side length of 2 mm to 10 mm, and the width of the groove is 0.5 mm to 1 mm.

[0013] Furthermore, in some embodiments of the present invention, a plurality of the first exhaust holes are provided at the intersection of each of the grooves, wherein each of the first exhaust holes is respectively connected to the second exhaust hole on the electrode net to provide uniform vacuum adsorption force to each position of the wafer.

[0014] Furthermore, in some embodiments of the present invention, the wafer tray further comprises a heating wire, which is disposed below the electrode mesh and is used to heat the wafer during a thin film deposition process to form a thin film on the front surface thereof.

[0015] Furthermore, in some embodiments of the present invention, the electrode mesh also provides a radio frequency voltage to the wafer during the thin film deposition process to form a thin film on the front surface thereof.

[0016] In addition, the thin film deposition device provided according to the second aspect of the present invention includes: a process chamber, including a wafer tray as described in the first aspect of the present invention; and an air pressure regulating module, which is used to form high pressure and low pressure thin film deposition conditions in the process chamber, respectively, so as to perform thin film deposition on the wafer carried on the wafer tray. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above features and advantages of the present invention will be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or characteristics may have the same or similar reference numerals.

[0018] Figure 1 A schematic structural diagram of a wafer tray provided according to some embodiments of the present invention is shown.

[0019] Figure 2A A schematic diagram of the overall structure of a planar substrate provided according to some embodiments of the present invention is shown.

[0020] Figure 2B A schematic diagram of a partial structure of a planar substrate provided according to some embodiments of the present invention is shown.

[0021] Figure 3 A schematic structural diagram of an electrode network provided according to some embodiments of the present invention is shown.

[0022] Reference numerals:

[0023] 10 Wafer Tray

[0024] 101 Flat Substrate

[0025] 1011 First exhaust hole

[0026] 1012 Groove

[0027] 1013 flat bump

[0028] 102 electrode mesh

[0029] 1021 First Area

[0030] 1022 Second Area

[0031] 1023 ejector pin vias

[0032] 1024 Second exhaust hole

[0033] 1025 axis of symmetry

[0034] 103 heating wire DETAILED DESCRIPTION

[0035] The following specific embodiments illustrate the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiment is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will include many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description.

[0036] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0037] Furthermore, the terms "upper," "lower," "left," "right," "top," "bottom," "horizontal," and "vertical" used in the following description should be understood to refer to the orientations depicted in that section and the accompanying drawings. These relative terms are used solely for convenience of description and do not necessarily imply that the devices described herein must be manufactured or operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0038] It will be understood that although the terms "first," "second," "third," etc. may be used herein to describe various components, regions, layers, and / or portions, these components, regions, layers, and / or portions should not be limited by these terms, and these terms are merely used to distinguish different components, regions, layers, and / or portions. Thus, a first component, region, layer, and / or portion discussed below may be referred to as a second component, region, layer, and / or portion without departing from some embodiments of the present invention.

[0039] As mentioned above, existing wafer trays include electrostatic adsorption wafer trays and vacuum adsorption wafer trays. However, when there is a need to frequently switch between high-pressure and low-pressure working conditions, if an electrostatic adsorption wafer tray is used, reactive gas will be present in the gaps between the bumps of the wafer tray under high-pressure working conditions, resulting in film formation on the back of the wafer, thus failing to meet the quality requirements of thin film deposition. If a vacuum adsorption wafer tray is used, the vacuum adsorption capacity will be insufficient under low-pressure working conditions, resulting in the inability to eliminate wafer warping. Therefore, wafer trays that only have electrostatic adsorption or vacuum adsorption methods can no longer meet the working conditions that require frequent switching between high-pressure and low-pressure working conditions.

[0040] In order to overcome the above-mentioned defects of the prior art, the art urgently needs a wafer tray and a thin film deposition device that can simultaneously meet the adsorption requirements of high-pressure and low-pressure conditions, thereby suppressing the formation of a thin film on the back of the wafer under high-pressure conditions and effectively suppressing and / or eliminating the warping of the wafer under low-pressure conditions.

[0041] In some non-limiting embodiments, the wafer tray provided in the first aspect of the present invention can be configured in the thin film deposition apparatus provided in the second aspect of the present invention. Specifically, the thin film deposition apparatus provided in the second aspect of the present invention includes a process chamber and a pressure adjustment module. Here, the process chamber includes the wafer tray of the first aspect of the present invention. The pressure adjustment module is used to respectively establish high and low pressure thin film deposition conditions in the process chamber to perform thin film deposition on the wafers carried by the wafer tray.

[0042] Please refer to Figure 1 , Figure 1 A schematic structural diagram of a wafer tray provided according to some embodiments of the present invention is shown.

[0043] like Figure 1 As shown, the wafer tray 10 includes a planar substrate 101, an electrode mesh 102, and a heating wire 103. Specifically, the planar substrate 101 is disposed on the upper surface of the wafer tray 10 and is provided with a first air extraction hole 1011 and a groove 1012 connected to the first air extraction hole 1011. The planar substrate 101 is used to vacuum-adsorb the wafer on the planar substrate 101 under high pressure conditions to suppress the formation of a thin film on the back surface. The electrode mesh 102 is disposed below the planar substrate 101 and is used to electrostatically adsorb the wafer under low pressure conditions to suppress and / or eliminate wafer warping. The heating wire 103 is disposed below the electrode mesh 102 and is used to heat the wafer during the thin film deposition process to form a thin film on the front surface.

[0044] In some embodiments, the electrode mesh 102 can also provide radio frequency voltage to the wafer during the thin film deposition process to form a thin film on its front surface. Therefore, by placing the heating filament 103 below the electrode mesh 102, the present invention can effectively shorten the distance between the electrode mesh 102 and the wafer, thereby reducing the impedance between the electrode mesh 102 and the wafer to meet the radio frequency requirements of the thin film deposition process.

[0045] Please refer to further Figure 2A-2B . Figure 2A A schematic diagram of the overall structure of a planar substrate provided according to some embodiments of the present invention is shown. Figure 2B A schematic diagram of a partial structure of a planar substrate provided according to some embodiments of the present invention is shown.

[0046] exist Figure 2A-2B In the illustrated embodiment, the electrode network 102 may include multiple regions, wherein at least one first region 1021 is loaded with a positive voltage, and the remaining at least one second region 1022 is loaded with a negative voltage, so as to perform bipolar electrostatic adsorption on the wafer.

[0047] Furthermore, the first diameter of the electrode mesh 102 can be larger than the second diameter of the wafer, and its projection in the vertical direction can cover the wafer. In addition, the at least one first region 1021 and the at least one second region 1022 can maintain axisymmetry along the symmetry axis 1025 to provide uniform electrostatic adsorption force to all locations on the wafer.

[0048] Furthermore, 2N+1 ejector vias 1023 and a second exhaust hole 1024 may preferably be provided on the electrode mesh 102. Here, N is a positive integer. The second exhaust hole 1024 is connected to the first exhaust hole 1011, and is used to form a vacuum negative pressure on the back of the wafer through the first exhaust hole 1011 and the groove 1012 to vacuum adsorb the wafer. The ejector via 1023 and the second exhaust hole 1024 have the same area. N+1 ejector vias 1023 may be provided in the at least one first region 1021, and a second exhaust hole 1024 and N ejector vias 1023 may be provided in the at least one second region 1022 to ensure that the actual area of each positive voltage region is equal to that of each negative voltage region, thereby providing uniform electrostatic adsorption force to each position of the wafer.

[0049] Please refer to further Figure 3 , Figure 3 A schematic structural diagram of an electrode network provided according to some embodiments of the present invention is shown.

[0050] like Figure 3As shown, the upper surface of the planar substrate 101 is provided with a plurality of grooves 1012, wherein each groove 1012 intersects with each other to form a plurality of planar bumps 1013 that contact the wafer. Here, the planar bumps 1013 include, but are not limited to, triangles, rectangles, and parallelograms. The wafer tray 10 can provide a vacuum suction force corresponding to the negative vacuum pressure therein to the wafer via the plurality of grooves 1012, and an electrostatic suction force corresponding to the total area of the wafer via the plurality of planar bumps 1013.

[0051] Furthermore, in some embodiments, a plurality of first air extraction holes 1011 are preferably provided at the intersections of each groove 1012. Each first air extraction hole 1011 is connected to a second air extraction hole 1024 on the electrode mesh 102, thereby providing uniform vacuum suction force to all locations on the wafer. Furthermore, the planar substrate 101 is further provided with ejector pin holes 1023 that coincide with the positions of the ejector pin holes 1023 on the electrode mesh 102, thereby allowing ejector pins to pass smoothly through the wafer tray 10.

[0052] Furthermore, in some embodiments, the above-mentioned planar protrusion 1013 can be a parallelogram with a side length of 2mm to 10mm, the width of the groove 1012 can be 0.5mm to 1mm, and the depth of the groove 1012 can be 0.3mm to 1mm, so that the electrostatic adsorption force and the vacuum adsorption force can be taken into account by adjusting the area ratio of the planar protrusion 1013 and the groove 1012, so as to avoid the formation of a thin film in a designated area on the back side of the wafer (for example: within 0.5 mm from the outer diameter of the wafer) while ensuring sufficient electrostatic adsorption force and sufficient back-side exhaust capacity, and effectively prevent and / or warping of the wafer.

[0053] In summary, the present invention provides a wafer tray for use in chemical vapor deposition (PECVD) equipment, with both electrostatic and vacuum adsorption capabilities. The tray utilizes planar bumps in a grid-like shape, using the gaps between each planar bump unit as a vacuum adsorption channel. Electrostatic adsorption is performed on the wafers placed on the wafers through the contact surfaces of each planar bump with the wafers, thereby simultaneously meeting the adsorption requirements of both high-pressure and low-pressure conditions, suppressing the formation of thin films on the backside of the wafers, and effectively preventing and / or eliminating wafer warping.

[0054] Although the above methods are illustrated and described as a series of acts for simplicity of explanation, it is to be understood and appreciated that these methods are not limited by the order of the acts, as some acts may occur in a different order and / or concurrently with other acts from those illustrated and described herein or not illustrated and described herein but understandable to those skilled in the art according to one or more embodiments.

[0055] 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 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 the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wafer tray, characterized in that: include: a planar substrate disposed on the upper surface of the wafer tray, provided with a first air extraction hole and a groove communicating with the first air extraction hole, for vacuum adsorbing the wafer on the planar substrate under high pressure conditions to suppress the formation of a thin film on the back surface thereof; as well as An electrode mesh is provided under the planar substrate and is used to electrostatically adsorb the wafer under low-pressure conditions to suppress and / or eliminate warping of the wafer, wherein the electrode mesh includes at least one first area and at least one second area that maintain axial symmetry, 2N+1 ejector vias and one second exhaust hole are provided on the electrode mesh, the ejector via and the second exhaust hole have the same area, N+1 ejector vias are provided in at least one first area, and the second exhaust hole and N ejector vias are provided in at least one second area to provide uniform electrostatic adsorption force to each position of the wafer.

2. The wafer tray according to claim 1, wherein: The at least one first region is loaded with a positive voltage, and the remaining at least one second region is loaded with a negative voltage, so as to perform bipolar electrostatic adsorption on the wafer.

3. The wafer tray according to claim 2, wherein: The vertical projection of the electrode mesh covers the wafer to provide uniform electrostatic adsorption force to each position of the wafer.

4. The wafer tray according to claim 3, wherein: The second exhaust hole is connected to the first exhaust hole and is used to form a vacuum negative pressure on the back side of the wafer through the first exhaust hole and the groove to vacuum absorb the wafer.

5. The wafer tray according to claim 1, wherein: The upper surface of the planar substrate is provided with a plurality of grooves, wherein the grooves intersect with each other to form a plurality of planar bumps that contact the wafer. The wafer tray provides a vacuum adsorption force corresponding to the vacuum negative pressure therein to the wafer via the plurality of grooves, and provides an electrostatic adsorption force corresponding to the total area of the wafer via the plurality of planar bumps.

6. The wafer tray according to claim 5, wherein: The planar protrusion is a parallelogram with a side length of 2 mm to 10 mm, and the width of the groove is 0.5 mm to 1 mm.

7. The wafer tray according to claim 5, wherein: A plurality of first exhaust holes are provided at the intersection of each of the grooves, wherein each of the first exhaust holes is respectively connected to the second exhaust hole on the electrode net to provide uniform vacuum adsorption force to each position of the wafer.

8. The wafer tray according to claim 1, wherein: Also includes: The heating wire is arranged under the electrode mesh and is used to heat the wafer during the thin film deposition process to form a thin film on the front side thereof.

9. The wafer tray according to claim 8, wherein: The electrode mesh also provides radio frequency voltage to the wafer during the thin film deposition process to form a thin film on the front side thereof.

10. A thin film deposition device, characterized in that: include: A process chamber comprising the wafer tray according to any one of claims 1 to 9; as well as The air pressure regulating module is used to form high-pressure and low-pressure thin film deposition working conditions in the process chamber respectively, so as to perform thin film deposition on the wafers carried on the wafer tray.

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