Heating plate, thin film deposition equipment and thin film deposition method

Abstract

The present invention provides a heating plate, a thin film deposition device and a thin film deposition method. The heating plate includes: a substrate for carrying and heating a wafer to be processed to deposit a thin film on the back thereof; and a base provided below the substrate to support the substrate, wherein the base is provided with a curved surface extending in a transverse direction, which undergoes thermal expansion deformation greater than that of the substrate during heating, and provides a transverse pulling force to the substrate to suppress the thermal expansion deformation of the substrate. By providing a curved surface extending in a transverse direction on the base of the heating plate, and utilizing the thermal expansion deformation greater than that of the substrate during heating to provide a transverse pulling force to the substrate, the present invention can effectively suppress the thermal expansion deformation of the substrate, thereby improving the film forming quality on the back of the wafer.

Description

Technical Field

[0001] The present invention relates to a processing technology of semiconductor devices, and in particular to a heating disk, a thin film deposition device, and a thin film deposition method. Background Art

[0002] The heating plate is a device for heating semiconductor wafers and is widely used in the processing of semiconductor devices. In the back deposition process of the wafer, due to the continuous bombardment of radio frequency (RF) energy, the temperature of the central area of ​​the substrate of the heating plate facing the reaction chamber will continue to rise, causing the substrate to expand and deform toward the surrounding area. However, since the base of the heating plate facing away from the reaction chamber is at a lower temperature, it can only undergo a smaller amount of thermal expansion, causing the central area of ​​the substrate to bulge upward, affecting the uniformity of the deposition space on the back of the wafer and reducing the film formation quality on the back of the wafer. In addition, the repeated bulging and deformation of the heating plate substrate can easily lead to desoldering of the internal structure of the heating plate, thereby shortening the service life of the heating plate.

[0003] In order to overcome the above-mentioned defects of the prior art, there is an urgent need in the art for an improved heating plate structure for suppressing the thermal expansion deformation of the substrate to improve the film forming quality on the back side of the wafer. Summary of the Invention

[0004] 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.

[0005] In order to overcome the above-mentioned defects of the prior art, the present invention provides a heating plate, a thin film deposition device and a thin film deposition method. A curved surface extending laterally is provided on the base of the heating plate so that the thermal expansion deformation thereof during heating is greater than that of the substrate, thereby providing a lateral pulling force to the substrate to suppress the thermal expansion deformation of the substrate and improve the film forming quality on the back side of the wafer.

[0006] Specifically, the heating plate provided according to the first aspect of the present invention includes a substrate and a base. The substrate is used to support and heat a wafer to be processed to deposit a thin film on its backside. The base is disposed below the substrate to support the substrate. The base has a laterally extending curved surface that, during heating, undergoes thermal expansion deformation greater than that of the substrate, providing a lateral tensile force to the substrate to suppress thermal expansion deformation.

[0007] Furthermore, in some embodiments of the present invention, the substrate is provided with a plurality of gas outlet holes. The base is provided with a gas distributor. A gap is maintained between the curved surface and the substrate to form a gas mixing chamber. The gas distributor is connected to a reaction gas source and is configured to disperse and transmit the reaction gas provided by the reaction gas source into the gas mixing chamber, and then transmit the reaction gas through the plurality of gas outlet holes to the reaction chamber above the substrate for thin film deposition.

[0008] Furthermore, in some embodiments of the present invention, a central area of ​​the curved surface bends downward away from the substrate to expand the volume of the gas mixing cavity and enhance its gas mixing effect.

[0009] Furthermore, in some embodiments of the present invention, the gas distributor includes a gas pipe and a baffle. The first end of the gas pipe is connected to the reaction gas source, while the second end of the gas pipe faces the baffle. The baffle is perpendicular to the second end of the gas pipe and has a height no greater than the edge of the curved surface near the substrate. The baffle is used to deflect the reaction gas output through the second end of the gas pipe toward the curved surface to promote mixing of the reaction gases.

[0010] Furthermore, in some embodiments of the present invention, the baffle is welded to the central area of ​​the curved surface via at least one first position, and the at least one first position is biased toward the same side of the baffle.

[0011] Furthermore, in some embodiments of the present invention, the gas distributor is also connected to a carrier gas source, for dispersing the carrier gas provided by the carrier gas source into the gas mixing chamber, and then transmitting the carrier gas to the reaction chamber above the substrate through the multiple gas outlet holes, so as to purge the gas duct, the baffle, the gas mixing chamber and / or the reaction chamber.

[0012] Furthermore, in some embodiments of the present invention, the substrate is welded to the base via multiple second locations. The base is welded to the main frame of the thin film deposition apparatus via multiple third locations. The multiple second locations are located in the edge region of the substrate, facing the lower surface of the base. Furthermore, the bottom of the base is provided with an extension extending downwardly away from the substrate. The multiple third locations are located on the lower surface of the extension.

[0013] Furthermore, in some embodiments of the present invention, the welded connection is achieved by electron beam welding. In addition, the welded portion of the welded connection adopts a multi-skin design to increase bending strength.

[0014] In addition, the thin film deposition apparatus provided according to the second aspect of the present invention includes a reaction chamber in which the heating plate provided according to the first aspect of the present invention is disposed.

[0015] In addition, the above-mentioned thin film deposition method provided according to the third aspect of the present invention includes the following steps: placing the wafer to be processed on the above-mentioned heating plate provided by the first aspect of the present invention; and heating the wafer via the heating plate to deposit a thin film on its back side. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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.

[0017] Figure 1 A schematic cross-sectional view of a heating plate provided according to some embodiments of the present invention is shown.

[0018] Figure 2 A schematic cross-sectional view of a welding point of a heating plate according to some embodiments of the present invention is shown.

[0019] Figure 3 A schematic top view of baffle welding points provided according to some embodiments of the present invention is shown.

[0020] Figure 4 A schematic flow chart of a thin film deposition method according to some embodiments of the present invention is shown.

[0021] Reference numerals

[0022] 11 base plate

[0023] 12 base

[0024] 13 Heating wire

[0025] 141 airway

[0026] 142 baffle

[0027] 21 Second position

[0028] 22 Third position

[0029] 23 handle

[0030] 31 First Position

[0031] 32 Free Points

[0032] a, b surfaces DETAILED DESCRIPTION

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] As mentioned above, during the backside deposition process of the wafer, due to the continuous bombardment of radio frequency (RF) energy, the temperature of the central area of ​​the substrate of the heating disk facing the reaction chamber will continue to rise, causing the substrate to expand and deform toward the surrounding area. However, since the base of the heating disk facing away from the reaction chamber is at a lower temperature, it can only undergo a smaller amount of thermal expansion, causing the central area of ​​the substrate to bulge upward, affecting the uniformity of the deposition space on the back side of the wafer and reducing the film formation quality on the back side of the wafer. In addition, the repeated bulging and deformation of the heating disk substrate can easily lead to desoldering of the internal structure of the heating disk, thereby shortening the service life of the heating disk.

[0038] In order to overcome the above-mentioned defects of the prior art, the present invention provides a heating plate, a thin film deposition device and a thin film deposition method. A curved surface extending laterally is provided on the base of the heating plate so that the thermal expansion deformation thereof during heating is greater than that of the substrate, thereby providing a lateral pulling force to the substrate to suppress the thermal expansion deformation of the substrate and improve the film forming quality on the back side of the wafer.

[0039] In some non-limiting embodiments, the thin film deposition method provided in the third aspect of the present invention can be implemented using the heating plate provided in the first aspect of the present invention. Further, the heating plate can be configured in the reaction chamber of the thin film deposition apparatus provided in the second aspect of the present invention.

[0040] Please refer to Figure 1 , Figure 1 A schematic cross-sectional view of a heating plate provided according to some embodiments of the present invention is shown.

[0041] exist Figure 1 In the illustrated embodiment, the heating plate provided by the first aspect of the present invention may be configured with a substrate 11 and a base 12. The substrate 11 is provided with at least one heating filament 13 for supporting and heating the wafer to be processed to deposit a thin film on its backside. The base 12 is provided below the substrate 11 to support the substrate 11. The upper surface a of the base 12 may be modified from a traditional flat surface to a laterally extending curved surface to increase its linear length in at least one planar direction (e.g., the X and / or Y directions).

[0042] As such, when the heating plate begins heating the wafer for backside thin film deposition, surface a undergoes significant thermal expansion and deformation. Because the linear length of surface a in the X and / or Y directions is greater than the linear length of the flat upper surface b of substrate 11 in the corresponding directions, its first deformation at the same temperature is greater than the second deformation of surface b. This applies lateral tension in the X and / or Y directions to surface b, reducing its deformation amplitude with temperature fluctuations. This improves the film quality on the backside of the wafer and extends the service life of the heating plate.

[0043] Furthermore, in some embodiments of the present invention, a gap can be maintained between surface a and substrate 11 to form a gas mixing chamber between the substrate and the base. Accordingly, the substrate 11 can be provided with multiple gas outlets, while the base is provided with a gas distributor. The gas distributor comprises a gas guide tube 141 and a baffle 142. The first end of the gas guide tube 141 is connected to a reaction gas source and is used to disperse and transmit the reaction gas provided by the reaction gas source into the gas mixing chamber, and then transmit it through the multiple gas outlets to the reaction chamber above the substrate for thin film deposition.

[0044] Furthermore, the central region of surface a can preferably be curved downward, away from substrate 11, to expand the volume of the gas mixing chamber and enhance its gas mixing effect. The baffle 142 is disposed perpendicular to the second end of the gas guide tube 141 and is no taller than the edge of surface a near substrate 11. It is used to deflect the reactant gas output from the second end of the gas guide tube 141 toward surface a, thereby promoting gas mixing.

[0045] Furthermore, in some embodiments of the present invention, the gas distributor 14 can also be connected to a carrier gas source. Thus, during the purge phase before and after the thin film deposition process, technicians can adjust the switching valve to disperse the carrier gas provided by the carrier gas source into the gas mixing chamber, and then transmit it through multiple gas outlets to the reaction chamber above the substrate 11 to purge the gas guide pipe, baffle, gas mixing chamber, and / or reaction chamber.

[0046] Please refer to further Figure 2 and Figure 3 . Figure 2 A schematic cross-sectional view of a welding point of a heating plate according to some embodiments of the present invention is shown. Figure 3 A schematic top view of baffle welding points provided according to some embodiments of the present invention is shown.

[0047] exist Figure 2 In the illustrated embodiment, the substrate 11 can be welded to the base 12 via a plurality of second locations 21. These second locations 21 can be located at the edge of the substrate 11, facing the lower surface of the base 12. Furthermore, the base 12 can have an extension at its bottom that extends downward, away from the substrate 11. The lower surface of this extension can have a plurality of third locations 22. These third locations 22 can be welded to a heating plate handle 23, which is then connected to the main frame of the thin film deposition apparatus via this handle 23.

[0048] Therefore, by adjusting the splicing position between the heating disk substrate 11 and the base 12 from the vertical plane to the horizontal plane, and adjusting the welding position of the heating disk and the handle 23 to a farther place with lower temperature through the extension part, the present invention can effectively reduce the thermal deformation of vertical friction welding, thereby making the welding more stable.

[0049] In addition, Figure 3 In the illustrated embodiment, the baffle 142 can be welded to the central region of surface a via at least one first location 31. Here, the at least one first location 31 is located on the same side of the baffle 142 (e.g., the front, rear, left, or right side), leaving at least one free point 32. This allows the baffle 142 and surface a of the base 12 to expand and deform due to heat, allowing the deformation to be released through the free point 32, thereby preventing the remaining first locations 31 from becoming unsoldered.

[0050] Furthermore, the welded connections at the first location 31, the second location 21, and / or the third location 22 can be achieved using an electron beam welding process, replacing the original friction welding technology, thereby reducing the deformation at the weld point. In addition, the welded portion of the welded connection can adopt a multi-skin design to increase bending strength.

[0051] Furthermore, the thin film deposition apparatus provided according to the second aspect of the present invention includes a reaction chamber. The reaction chamber is equipped with the heating plate described in any one of the above embodiments and is connected to a reaction gas source. After receiving reaction gas from the reaction gas source, the reaction gas surrounding the wafer is heated via the heating plate to deposit a thin film on the front and / or back surface of the wafer.

[0052] In addition, please refer to Figure 4 , Figure 4 A schematic flow chart of a thin film deposition method according to some embodiments of the present invention is shown.

[0053] like Figure 4 As shown, during the thin film deposition process, the thin film deposition equipment can first place the wafer to be processed above the substrate 11 of the above-mentioned heating disk provided in the first aspect of the present invention, and then operate the heating wire 13 in the heating disk to heat the wafer above it to deposit a thin film on its back.

[0054] In summary, the above-mentioned heating plate, thin film deposition equipment and thin film deposition method provided by the present invention can all provide a curved surface extending laterally on the base 12 of the heating plate, so that the base 12 undergoes thermal expansion deformation greater than that of the substrate 11 during heating, thereby providing a lateral pulling force to the substrate 11 to suppress the thermal expansion deformation of the substrate 11 and improve the film formation quality on the back of the wafer.

[0055] 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.

[0056] 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 heating plate, characterized in that: include: A substrate, used to hold and heat the wafer to be processed in order to deposit a thin film on its backside; as well as The base is provided below the substrate to support the substrate, wherein the base is provided with a curved surface extending in the transverse direction, which undergoes thermal expansion deformation greater than that of the substrate during heating, and provides a transverse pulling force to the substrate to suppress the thermal expansion deformation of the substrate.

2. The heating plate according to claim 1, wherein The substrate is provided with a plurality of air outlet holes, the base is provided with an air separator, and the curved surface and the substrate maintain a gap to form a gas mixing cavity, wherein, The gas distributor is connected to a reaction gas source and is used to disperse and transmit the reaction gas provided by the reaction gas source into the gas mixing chamber, and then transmit the reaction gas to the reaction chamber above the substrate through the multiple gas outlets for thin film deposition.

3. The heating plate according to claim 2, wherein: The central area of ​​the curved surface bends downward away from the substrate to expand the volume of the gas mixing cavity and improve its gas mixing effect.

4. The heating plate according to claim 3, wherein The gas distributor includes an air guide tube and a baffle, wherein the first end of the air guide tube is connected to the reaction gas source, and the second end thereof faces the baffle, the baffle is perpendicular to the second end of the air guide tube, and the height thereof is no greater than the edge area of ​​the curved surface close to the substrate, and is used to block the reaction gas output through the second end of the air guide tube toward the curved surface to promote gas mixing of the reaction gas.

5. The heating plate according to claim 4, wherein: The baffle is welded to the central area of ​​the curved surface via at least one first position, wherein the at least one first position is biased toward the same side of the baffle.

6. The heating plate according to claim 4, wherein: The gas distributor is also connected to a carrier gas source for dispersing the carrier gas provided by the carrier gas source into the gas mixing chamber, and then transmitting the carrier gas to the reaction chamber above the substrate through the multiple gas outlet holes to purge the gas guide pipe, the baffle, the gas mixing chamber and / or the reaction chamber.

7. The heating plate according to claim 1, wherein The substrate is connected to the base through a plurality of second position welding, and the base is connected to the main frame of the thin film deposition device through a plurality of third position welding, wherein, The plurality of second positions are located at the edge region of the substrate facing the lower surface of the base, and / or An extension portion is provided at the bottom of the base and extends downward away from the substrate, and the plurality of third positions are located on a lower surface of the extension portion.

8. The heating plate according to claim 5 or 7, wherein: The welded connection is achieved by electron beam welding, and / or The welded portion of the welded connection adopts a fleshy design to increase the bending strength.

9. A thin film deposition device, characterized in that: include: A reaction chamber, wherein the heating plate according to any one of claims 1 to 8 is arranged.

10. A thin film deposition method, characterized in that: The following steps are involved: placing a wafer to be processed on a heating plate as claimed in any one of claims 1 to 8; as well as The wafer is heated via the heating plate to deposit a thin film on the back side thereof.

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