Vacuum suction system and method

Abstract

The present application relates to a vacuum chucking system and method. The vacuum chucking system is used for chucking and releasing a wafer on a bearing surface of a vacuum chucking heater in a reaction chamber, the reaction chamber has an exhaust port, and the vacuum chucking heater has a vent port. The vacuum chucking system comprises: a first pipeline for fluidly coupling the exhaust port of the reaction chamber with a vacuum pump; a second pipeline for fluidly coupling the vent port of the vacuum chucking heater with the vacuum pump; and a third pipeline connected to the second pipeline and for supplying a gas from a gas source to the vacuum chucking system. When chucking the wafer by using the vacuum chucking system, the pressure in the chucking pipeline inside the heater can be conveniently adjusted during the process of chucking and releasing the wafer, so as to adjust the pressure difference between the back surface and the front surface of the wafer, which is beneficial to improve the operation efficiency.

Description

Technical Field

[0001] This application relates to an apparatus for heating wafers in a semiconductor processing chamber, and more particularly to a vacuum adsorption heater. This application also relates to a vacuum adsorption system that can be used in conjunction with the vacuum adsorption heater, and a method for adsorbing wafers using the vacuum adsorption system. Background Technology

[0002] A wafer or substrate is a base used to fabricate semiconductor devices. To fabricate semiconductor devices (such as integrated circuits, semiconductor light-emitting devices, etc.), the wafer or substrate needs to be placed in a semiconductor processing chamber (also called a reaction chamber) for heating and deposition processes (e.g., chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), etc.) to deposit a thin film on the surface of the wafer or substrate. During the process, the wafer can be fixed to a heater within the processing chamber using methods such as vacuum adsorption.

[0003] However, existing vacuum adsorption heaters, vacuum adsorption systems, and adsorption methods have many drawbacks.

[0004] For example, the wafer carrier surface of the heater and the wafer are in surface contact, which can easily lead to uneven contact. For example, due to the surface roughness of the carrier surface and the wafer itself, as well as their processing errors, when the wafer is placed on the carrier surface, the two may not fit completely and evenly, and some positions may be suspended or there may be uneven gaps in different positions.

[0005] In this situation, on the one hand, uneven heating of different parts of the wafer may occur when the heater heats it, resulting in poor heating effect and even affecting the wafer yield; on the other hand, insufficient vacuum adsorption force on the wafer may occur during operation, resulting in poor adsorption effect; the wafer may even move on the support surface, especially in processing chambers with high gas flow and high pressure, where the possibility of wafer movement is greater.

[0006] In addition, some vacuum adsorption structures on vacuum adsorption heaters (such as through holes on the heating plate, adsorption pipes inside the heating plate, etc.) are difficult to process due to their small size and deep depth, resulting in greater processing difficulty and higher processing costs.

[0007] Furthermore, existing vacuum adsorption systems typically rely solely on a vacuum pump to evacuate gas (air) from the adsorption tubing inside the heater. This controls the pressure difference between the back side (the side in contact with the wafer's substrate surface) and the front side. Therefore, during wafer adsorption and release, the gas pressure within the adsorption tubing can only be controlled by operating the vacuum pump (or a valve on the vacuum pump line), thus controlling the pressure difference between the back and front sides and consequently the adsorption force on the wafer. However, this method is inconvenient (or even impossible) for adjusting the adsorption force on the wafer as needed. Moreover, during wafer release, the pressure on the back side must be roughly equal to the front pressure by closing the vacuum pump (or the valve on the vacuum pump line) and simultaneously allowing the gas in the reaction chamber to automatically flow into the adsorption tubing inside the heater until it reaches the back side of the wafer. This process is time-consuming and reduces operational efficiency.

[0008] Therefore, it is necessary to improve the existing vacuum adsorption heaters, vacuum adsorption systems, and methods for adsorbing wafers using vacuum adsorption systems in order to solve the above-mentioned technical problems. Summary of the Invention

[0009] The purpose of this application is to address at least one of the problems in the prior art described above, by providing an improved vacuum adsorption heater. This heater enables a uniform point contact between the wafer placed on the support surface and the support surface, thus effectively adsorbing the wafer during operation and preventing it from moving on the heater support surface (even in a reaction chamber with high gas flow and high pressure), while also ensuring uniform heating of the entire wafer, thereby improving the product quality of the wafer.

[0010] Meanwhile, this application also provides a vacuum adsorption system. When adsorbing wafers using this vacuum adsorption system, the gas pressure in the adsorption pipeline inside the heater can be easily adjusted during both the adsorption and release of the wafers, thereby adjusting the pressure difference between the back and front sides of the wafer (i.e., adjusting the magnitude of the adsorption force). Therefore, it can not only meet various adsorption needs of wafers (for example, some wafer processing processes require a larger adsorption force, while others require a smaller adsorption force), but also, during the release of the wafers, gas can be introduced to rapidly raise the pressure on the back side of the wafer to be equal to or even greater than the pressure on the front side. Thus, the adsorption force can be eliminated and the wafers released in a short time, which is beneficial to improving work efficiency.

[0011] This application also provides a method for adsorbing wafers using the above-mentioned vacuum adsorption system. This method can effectively achieve the purpose of adjusting the adsorption force of the adsorbed wafers, and therefore has a wide range of applications and helps to improve the efficiency of wafer processing.

[0012] Some embodiments of this application provide a vacuum adsorption system for adsorbing and releasing wafers located on a support surface of a vacuum adsorption heater within a reaction chamber, the reaction chamber having an exhaust port and the vacuum adsorption heater having an vent port. The system includes: a first conduit for fluidly coupling the exhaust port of the reaction chamber to a vacuum pump; a second conduit for fluidly coupling the vent port of the vacuum adsorption heater to the vacuum pump; and a third conduit connected to the second conduit and for supplying gas from a gas source to the vacuum adsorption system.

[0013] In some embodiments of this application, a first valve is installed on the second pipeline near the vent, and the third pipeline is connected downstream of the first valve on the second pipeline.

[0014] In some embodiments of this application, a second valve is installed on the third pipeline.

[0015] In one embodiment, a pressure controller is further disposed on the third pipeline for regulating the flow rate of gas supplied to the vacuum adsorption system. The pressure controller may include a mass flow controller, an adjustable flow valve, and a pressure measuring device.

[0016] In one embodiment, a throttle valve is installed on the first pipeline; the second pipeline branches into a first manifold and a second manifold downstream of the first valve; the other end of the first manifold is connected to the first pipeline between the exhaust port of the reaction chamber and the throttle valve, and a third valve is installed on the first manifold; the other end of the second manifold is connected to the vacuum pump, and a fourth valve is installed on the second manifold.

[0017] In one embodiment, a pressure measuring device is further installed on the second manifold.

[0018] In one embodiment, the first valve, the second valve, the third valve, and the fourth valve are all electromagnetic pneumatic valves.

[0019] Some embodiments of this application also provide a method for adsorbing a wafer using a vacuum adsorption system according to any embodiment of this application, comprising: during the adsorption and / or release of the wafer, supplying gas from the gas source to an adsorption pipeline inside the vacuum adsorption heater using the second pipeline and the third pipeline to adjust the pressure difference between the back and front sides of the wafer, wherein the adsorption pipeline is in fluid communication with the vent.

[0020] In some embodiments of this application, during the adsorption of the wafer, gas from the gas source is supplied to the adsorption pipeline using the second pipeline and the third pipeline, so that the pressure on the back side of the wafer is kept 30-150 Torr lower than the pressure on its front side.

[0021] In some embodiments of this application, during the release of the wafer, gas from the gas source is supplied to the adsorption pipeline using the second and third pipelines, causing the pressure on the back side of the wafer to increase to a level greater than or equal to the pressure on its front side. For example, the pressure on the back side of the wafer is increased to 5-10 Torr greater than the pressure on its front side.

[0022] Some embodiments of this application provide a method for adsorbing wafers using a vacuum adsorption system according to any embodiment of this application, which includes the following steps:

[0023] (a) Placing the wafer: With the vacuum adsorption system in the off state, the wafer is placed on the support surface of the vacuum adsorption heater in the reaction chamber;

[0024] (b) Adsorbing the wafer: The vacuum adsorption system is activated, and gas is continuously drawn from the adsorption pipe inside the vacuum adsorption heater through the second pipe, so that the pressure on the back side of the wafer is kept lower than the pressure on its front side, thereby adsorbing the wafer onto the supporting surface of the vacuum adsorption heater, wherein the adsorption pipe is in fluid communication with the vent; and

[0025] (c) Releasing the wafer: After the wafer has been processed, the gas in the adsorption line inside the vacuum adsorption heater is stopped, and gas from the gas source is supplied to the adsorption line using the second line and the third line, so that the pressure on the back side of the wafer is increased to be equal to or greater than the pressure on its front side, thereby releasing the wafer.

[0026] In some embodiments, the above method further includes at least one of the following steps:

[0027] (a1) Prior to step (a), the supporting surface of the vacuum adsorption heater is heated (e.g., heated to 450-500°C), and the reaction chamber is evacuated to a vacuum state by the vacuum pump; and

[0028] (a2) After step (a) and before step (b), gas is injected into the reaction chamber to increase the gas pressure in the reaction chamber.

[0029] In some embodiments, in step (a2), step (b) begins when the gas pressure in the reaction chamber rises above a threshold (e.g., 100 Torr).

[0030] In some embodiments, in step (b), while the vacuum pump continuously draws gas from the adsorption line within the vacuum adsorption heater through the second line, gas from the gas source is supplied to the adsorption line through the second line and the third line, thereby keeping the gas pressure on the back side of the wafer 30-150 Torr lower than that on the front side.

[0031] As described above, in some embodiments of this application, a throttle valve is installed on the first pipeline; a first valve is installed on the second pipeline near the vent; the third pipeline is connected downstream of the first valve on the second pipeline, and a second valve is installed on the third pipeline; the second pipeline branches into a first manifold and a second manifold downstream of the first valve; the other end of the first manifold is connected to the first pipeline between the vent of the reaction chamber and the throttle valve, and a third valve is installed on the first manifold; and the other end of the second manifold is connected to the vacuum pump, and a fourth valve is installed on the second manifold.

[0032] In some embodiments, during step (a1), the first valve, the second valve, the third valve, and the fourth valve are all closed, and the throttle valve is open.

[0033] In some embodiments, during step (b), the first valve, the second valve, and the fourth valve are all open, and the third pneumatic valve is closed.

[0034] In some embodiments, in step (b), the flow rate of the gas in the third conduit (C) is adjusted such that the gas pressure on the back side of the wafer is kept 30-150 Torr lower than the gas pressure on its front side.

[0035] In some embodiments, during step (c), the first valve, the second valve, and the third valve are all open, and the fourth valve is closed.

[0036] In some embodiments, in step (c), the flow rate of the gas in the third conduit is adjusted such that the pressure on the back side of the wafer is increased to be equal to or greater than the pressure on the front side. For example, the flow rate of the gas in the third conduit (C) is adjusted such that the pressure on the back side of the wafer is increased to be 5-10 Torr greater than the pressure on the front side. Attached Figure Description

[0037] To more clearly illustrate the specific embodiments and technical effects of this application, the specific embodiments of this application are described below in conjunction with the accompanying drawings. For clarity and ease of arrangement, these drawings are not drawn to scale; for example, some drawings are enlarged to show local details, while others are reduced to show the overall structure. For clarity, the drawings may not show all components of a given device or apparatus. Finally, the same reference numerals are used throughout the specification and drawings to denote the same features. Wherein:

[0038] Figure 1 This is a perspective view of the overall structure of a vacuum adsorption heater according to certain embodiments of this application;

[0039] Figure 2 yes Figure 1 The top view of the heating plate of the vacuum adsorption heater shown more clearly illustrates the first distribution of grooves and bumps in the upper surface of the main body of the heating plate (i.e., the surface used to support the wafer).

[0040] Figure 2A yes Figure 2 An enlarged view at point A shows that the through hole on the heating plate is located in the innermost annular groove, and its diameter is greater than the width of the annular groove.

[0041] Figure 3 Similar to Figure 2 It is also a top view of the heating plate, showing a second distribution of grooves and protrusions on the upper surface of the heating plate;

[0042] Figure 4 Similar to Figure 2 It is also a top view of the heating plate, showing a third distribution of grooves and protrusions on the upper surface of the heating plate;

[0043] Figure 5 Similar to Figure 2 It is also a top view of the heating plate, showing a fourth distribution of grooves and protrusions on the upper surface of the heating plate;

[0044] Figure 6 Similar to Figure 2 This is also a top view of the heating plate, showing the fifth distribution of grooves and protrusions on the upper surface of the heating plate;

[0045] Figure 7 Similar to Figure 2 It is also a top view of the heating plate, showing the sixth distribution of grooves and protrusions on the upper surface of the heating plate;

[0046] Figure 8 Similar to Figure 2It is also a top view of the heating plate, showing the seventh distribution of grooves and protrusions on the upper surface of the heating plate;

[0047] Figure 9 yes Figure 1 The front view of the vacuum adsorption heater shown illustrates the structure of the front of the vacuum adsorption heater.

[0048] Figure 10 for Figure 9 A BB cross-sectional view, which shows the internal structure of the vacuum adsorption heater at the cross-sectional location;

[0049] Figure 11 yes Figure 1 The left view of the vacuum adsorption heater shown illustrates the structure of the side of the heater.

[0050] Figure 12 for Figure 11 A CC cross-sectional view showing the internal structure of the vacuum adsorption heater at the cross-sectional location;

[0051] Figure 12A for Figure 12 An enlarged view at point D schematically illustrates the vertical structure of the protrusions, grooves, and through-holes; and

[0052] Figure 13 This is a schematic diagram of the structure of a vacuum adsorption system according to certain embodiments of this application. Detailed Implementation

[0053] The embodiments of this application are described in detail below with reference to the accompanying drawings. A better understanding of the various aspects of this application will be achieved by referring to the accompanying drawings and reading the following description of the specific embodiments. It should be noted that these embodiments are merely exemplary and are only used to explain and illustrate the technical solutions of this application, and are not intended to limit this application. Those skilled in the art can make various modifications and variations based on these embodiments (e.g., changing the size and / or layout of the grooves and protrusions on the upper surface of the heating plate body). All technical solutions obtained through equivalent modifications are within the protection scope of this application.

[0054] The names of the various components used in this manual are for illustrative purposes only and are not intended to be limiting. Different manufacturers may use different names to refer to components that have the same function.

[0055] Vacuum adsorption heater

[0056] Figure 1 This is a perspective view of the overall structure of a vacuum adsorption heater according to an embodiment of this application. Figure 1As shown, the vacuum adsorption heater mainly includes a heating plate 10. The heating plate 10 includes a generally disc-shaped main body 1 and a support shaft 2 located below the main body 1.

[0057] like Figure 1 As shown, the main body 1 has an upper surface 11 for supporting the wafer. During operation, the main body 1 of the heating plate 10 is located in a reaction chamber, and the wafer (not shown) can be placed on the upper surface 11 of the main body 1 by a transfer device such as a robotic arm, and then fixed by vacuum adsorption. After the wafer is fixed, it can be subjected to operations such as deposition processing.

[0058] See Figure 1 and combined Figure 9-12 In some embodiments of this application, the main body 1 of the heating plate 10 and the support shaft 2 located below the main body 1 are formed as a single unit. For example, both can be made of ceramic and then formed as a single unit by means of adhesion or welding. Compared with heating plates that adopt a split structure (i.e., the main body and the support shaft are assembled together in a detachable manner), the integrated structure in this application not only eliminates the steps of installing, fixing and sealing the two, but also eliminates the sealing element between them, and greatly improves the sealing performance, thus effectively enhancing the vacuum adsorption effect.

[0059] See also Figure 1 and Figure 9-12 In terms of external structure, the vacuum adsorption heater further includes a cooling block 50 located outside the support shaft 2 and at least partially surrounding the support shaft 2, and a fixing block 60 located outside the cooling block 50 and clamping the cooling block 50. The fixing block 60 is used to fix the vacuum adsorption heater to the machine base. The specific structures of the cooling block 50 and the fixing block 60 can adopt designs known in the art, and will not be described in detail here.

[0060] In terms of internal structure, the vacuum adsorption heater further includes a heating element (not shown) located inside the main body 1 and a heating rod 40 electrically connected to the heating element. The heating element may include, but is not limited to, a resistance wire. The heating rod 40 may include a highly conductive material, such as copper, nickel, etc. The heating element, the heating rod 40, and the electrical connections between them may employ designs known in the art, which will not be described in detail here.

[0061] like Figure 10 and 12As shown, the support shaft 2 is a hollow structure that can accommodate multiple sequentially stacked quartz blocks 20 and / or polyetheretherketone (PEEK) blocks 30. A heating rod 40 is located inside the support shaft 2 and extends through the quartz blocks 20 and / or PEEK blocks 30, and can be electrically connected to an external power source. When the power is turned on, the heating element generates heat and transfers it to the wafer on the body 1 of the heating plate 10. The heating rod 40 also generates heat. The quartz blocks 20 and PEEK blocks 30 surrounding the heating rod 40 help to keep the heat inside the support shaft 2 substantially or minimally dissipated, thereby facilitating heat transfer to the wafer for heating. The quartz blocks 20 and PEEK blocks 30 also serve to provide electrical insulation between the components inside the support shaft 2.

[0062] In this application, the structure of the main body 1 of the heating plate 10 (especially the upper surface 11 that supports the wafer) has been specially designed. Details are as follows.

[0063] See Figure 1 , Figure 2 and Figure 2A ,in Figure 2 yes Figure 1 The top view of the heating plate 10 shown. Figure 2A for Figure 2 An enlarged view at point A. In this application, the main body 1 of the heating plate 10 further has the following structure:

[0064] ◆A plurality of grooves 12 extending downward from the upper surface 11, at least a portion of which are in fluid communication with each other;

[0065] ◆One or more through holes 13, which are in fluid communication with at least one groove 12; and

[0066] ◆ Multiple bumps 14 located on the upper surface 11 are used to support the wafer.

[0067] In some embodiments provided in this application, the plurality of grooves 12 and the plurality of protrusions 14 are substantially uniformly distributed on the upper surface 11. Those skilled in the art will understand that the plurality of grooves 12 and the plurality of protrusions 14 may not be uniformly distributed, or one of them may be uniformly distributed. For example, in some embodiments, the plurality of grooves 12 are substantially uniformly distributed, while the plurality of protrusions 14 are not uniformly distributed (e.g., the protrusions are more densely distributed in the middle portion and sparser at the periphery); in other embodiments, the plurality of protrusions 14 are substantially uniformly distributed, while the plurality of grooves 12 are not uniformly distributed (e.g., the grooves are denser closer to the middle portion and sparser towards the outer periphery).

[0068] Unlike existing technologies, in this application, since the upper surface 11 has bumps 14, the wafer and the upper surface 11 of the heating plate body can form a uniform point contact, and there can be a uniform gap between them. That is, these bumps 14 make the contact between the wafer and its supporting surface (i.e., the upper surface 11 of the body 1) more uniform, which helps to make each part of the wafer receive uniform adsorption force and uniform heating, thereby facilitating the processing of the wafer, helping to ensure the film quality on the wafer surface and improve its yield.

[0069] In some embodiments of this application, such as Figure 1 and Figure 2 As shown, the plurality of grooves 12 include a plurality of annular grooves 121 arranged concentrically and radial grooves 122 that fluidly communicate with the annular grooves 121. In one embodiment, all radial grooves 122 fluidly communicate with adjacent annular grooves 121, thereby all annular grooves 121 and radial grooves 122 are fluidly connected. Therefore, all grooves 12 are completely fluidly connected. Thus, by evacuating one groove 12, a vacuum can be drawn into all grooves 12, thereby providing an adsorption force for the wafer.

[0070] In some embodiments of this application, the width of both the annular groove 121 and the radial groove 122 is 0.5-1.5 mm, and the depth is less than or equal to 1.0 mm; the spacing between adjacent annular grooves 121 is 10-50 mm. More preferably, the width of both the annular groove 121 and the radial groove 122 is 0.5-1.0 mm, and the depth is less than or equal to 0.5 mm; the spacing between adjacent annular grooves 121 is 15-50 mm. Grooves with the above-mentioned size range are easy to process and help to effectively achieve wafer adsorption. For illustrative purposes only, the accompanying drawings of this application show a specific number of annular grooves 121 and radial grooves 122. It should be understood that the heating plate 10 may have any suitable number of annular grooves 121 and radial grooves 122.

[0071] Furthermore, such as Figure 2 and 2A As shown in some embodiments of this application, the main body 1 may include only one through hole 13, which is located at a groove 12, for example, on the innermost annular groove 121, and is thus in fluid communication with the annular groove 121, such as... Figure 2A As shown in the diagram. In other embodiments, the through-hole 13 may also be located at other recesses 12. Additionally, as... Figure 2AAs shown, the diameter of the through hole 13 is larger than the width of the groove 12, for example, it can be 0.8-1.8 mm. Because the through hole is relatively deep, a diameter within this range is easy to process and can achieve a good adsorption effect. Using only one through hole 13 also simplifies the processing and saves processing costs. In other embodiments, multiple through holes 13 can also be provided on the main body 1.

[0072] In some embodiments of this application, as shown in the figures, each bump 14 may be generally circular, but this application is not limited to this. When fabricating the body 10 of the heating plate 1, the bumps 14 can be directly sintered onto the upper surface 11. In some embodiments, the diameter of each bump 14 is 1.0-3.0 mm, and the height is less than or equal to 0.2 mm; the spacing between adjacent bumps 14 is 3-20 mm. Bumps with this size range are convenient for processing (e.g., convenient for designing the mold for the body 1 of the heating plate 10) and can effectively achieve uniform contact with the wafer. Preferably, the diameter of each bump 14 is 1.5-2.5 mm, and the height is less than or equal to 0.1 mm; the spacing between adjacent bumps 14 is 5-15 mm. Bumps with this size range are more conducive to their manufacturing and processing, and also help to provide uniform contact with the wafer.

[0073] To achieve better technical results, when designing the structure of the upper surface 11 of the main body 1 of the heating plate 10, it is necessary to consider the combination of the distribution of grooves 12 and protrusions 14. Several exemplary schemes will be described below with reference to the accompanying drawings. It should be understood that the distribution of grooves 12 and protrusions 14 is not limited to these schemes.

[0074] In the first type of scheme, such as Figure 2-4 As shown, the upper surface 11 of the main body 1 includes a total of 7 annular grooves 121. The width of the annular grooves 121 and the radial grooves 122 are both 1.0 mm, and the depth is both 0.5 mm; and the spacing between adjacent annular grooves 121 is 21.5 mm. In this type of design, the annular grooves 121 are relatively dense, thus making the adsorption force more uniform during operation and resulting in a better adsorption effect on the wafer.

[0075] In the first embodiment of this type of solution, such as Figure 2 As shown, each bump 14 has a diameter of 2.0 mm and a height of 0.1 mm; and multiple bumps 14 are distributed along the circumference, thus forming multiple concentric circles, with a spacing of 7 mm between adjacent bumps 14 on the same circumference and between adjacent circumferences. This structure helps to achieve uniform support for the wafer from the circumferential direction.

[0076] In a second embodiment of this type of scheme, such as Figure 3As shown, each protrusion 14 has a diameter of 2.0 mm and a height of 0.1 mm; and the multiple protrusions 14 are distributed in a triangle (for example, the three closest protrusions 14 can form an equilateral triangle), and the distance between adjacent protrusions 14 is 10 mm.

[0077] In a third embodiment of this type of scheme, such as Figure 4 As shown, each protrusion 14 has a diameter of 2.0 mm and a height of 0.1 mm; and the multiple protrusions 14 are distributed in a triangle (for example, the three closest protrusions 14 can form an equilateral triangle), and the distance between adjacent protrusions 14 is 5 mm.

[0078] In the second type of scheme, such as Figure 5-8 As shown, the upper surface 11 of the main body 1 includes four annular grooves 121. The width of both the annular grooves 121 and the radial grooves 122 is 1.0 mm, and the depth is 0.5 mm; the distance between adjacent annular grooves 121 is 43 mm. In this type of design, the annular grooves 121 are relatively sparse, making the heating plate 10 with this structure easier to manufacture and process, and facilitating mold design and manufacturing, thus reducing production costs.

[0079] In the first embodiment of this type of solution, such as Figure 5 As shown, each bump 14 has a diameter of 2.0 mm and a height of 0.1 mm; and multiple bumps 14 are distributed along the circumference, thus forming multiple concentric circles, with a spacing of 7 mm between adjacent bumps 14 on the same circumference and between adjacent circumferences. This structure helps to achieve uniform support for the wafer from the circumferential direction.

[0080] In a second embodiment of this type of scheme, such as Figure 6 As shown, each protrusion 14 has a diameter of 2.0 mm and a height of 0.1 mm; and multiple protrusions 14 are distributed along the circumference, thus forming multiple concentric circles. The distance between adjacent protrusions 14 on the same circumference and between adjacent circumferences is 15 mm. In this structure, the protrusions 14 are more sparse, thus facilitating processing.

[0081] In a third embodiment of this type of scheme, such as Figure 7 As shown, each protrusion 14 has a diameter of 2.0 mm and a height of 0.1 mm; and the multiple protrusions 14 are distributed in a triangle (for example, the three closest protrusions 14 can form an equilateral triangle), and the distance between adjacent protrusions 14 is 10 mm.

[0082] In a fourth embodiment of this type of solution, such as Figure 8As shown, each protrusion 14 has a diameter of 2.0 mm and a height of 0.1 mm; and the multiple protrusions 14 are distributed in a triangle (for example, the three closest protrusions 14 can form an equilateral triangle), and the distance between adjacent protrusions 14 is 5 mm.

[0083] Those skilled in the art will understand that the spacing between adjacent annular grooves 121 is the distance between corresponding points of the two annular grooves, that is, the distance between a corresponding point on the outermost edge (or center line or innermost edge) of one annular groove 121 and a corresponding point on the outermost edge (or center line or innermost edge) of another annular groove 121. The width of the groove refers to the distance between corresponding points on the two edges of the groove, and the depth refers to the distance from the bottom surface of the groove to the top edge of the groove. Similarly, the spacing between adjacent protrusions 14 also refers to the distance between corresponding points on the two protrusions 14 (e.g., the centers of the protrusions).

[0084] See further Figure 12 and Figure 12A , Figure 12 This is a cross-sectional view showing a portion of the internal structure of the vacuum adsorption heater. Figure 12A for Figure 12 The enlarged view at point D specifically shows the vertical structure of the protrusion 14, groove 12, and through hole 13 on the main body 1 of the heating plate 10. (See diagram below.) Figure 12A As shown, the diameter of the through hole 13 is larger than the width of the groove 12. In some embodiments, the diameter of the through hole 13 can be 0.8-1.8 mm. This size design facilitates both the processing of the through hole 13 and the achievement of good adsorption effect.

[0085] like Figure 12 As shown, the vacuum adsorption heater also includes a through-hole 131 penetrating the quartz block 20 and / or the PEEK block 30. The upper end of the through-hole 131 is in fluid communication with the through-hole 13, and the lower end can be fluidly coupled to a vacuum pump during operation. The vacuum pump can then draw gas from the groove 12 through the pipeline and the through-hole 131 and through-hole 13, creating a pressure difference between the back and front sides of the wafer, thereby adsorbing the wafer. In some embodiments, the diameter of the through-hole 131 is 2-3 mm; the depth of the through-hole 131 in each quartz block 20 or PEEK block 30 is 20-25 mm. Through-holes with this depth and diameter facilitate manufacturing.

[0086] To improve the adsorption effect, such as Figure 12 As shown, the vacuum adsorption heater further includes a sealing ring 16 located on the quartz block 20 and / or the PEEK block, around the through hole 131, thereby improving the sealing effect and preventing or reducing gas leakage.

[0087] In addition, such as Figure 12As shown, the vacuum adsorption heater also includes a sealing ring 15 located between the heating rod 40 and the quartz block 20 and / or PEEK block 30. The sealing ring 15 is fitted onto the heating rod 40 and clamped between adjacent quartz blocks 20 and / or PEEK blocks 30, thus enabling it to be securely fixed.

[0088] Vacuum adsorption system and method for adsorbing wafers

[0089] The following describes the vacuum adsorption system provided in this application and the method for adsorbing wafers using the vacuum adsorption system. This vacuum adsorption system can be used in conjunction with the vacuum adsorption heater described in this specification, or with a vacuum adsorption heater having other structures, for adsorbing wafers.

[0090] See Figure 13 The illustration schematically depicts a vacuum adsorption system according to an embodiment of this application. The system is used to adsorb and release the load-bearing surface (e.g., ) of a vacuum adsorption heater 200 located within a reaction chamber 100. Figure 1 The wafer (not shown) is on the upper surface 11 of the body 1 of the heating plate 10 shown. The reaction chamber 100 has an exhaust port 101; the vacuum adsorption heater 200 has a vent 201 (for example, the vent 201 can be connected to...). Figure 12 The through-hole 131 shown is for fluid communication. Although the entire vacuum adsorption heater 200 is shown in the figure as being located within the reaction chamber 100, in actual products, only a portion of the vacuum adsorption heater 200 may be present, for example... Figure 1 The main body 1 of the heating plate 10 shown and a part of the support shaft 2 (e.g., the part above the cooling block 50 (including the cooling block 50)) are located inside the reaction chamber 100.

[0091] like Figure 13 As shown, the vacuum adsorption system includes:

[0092] ◆First pipeline A, which is used to fluidly couple the evacuation port 101 of the reaction chamber 100 to the vacuum pump 300;

[0093] ◆Second conduit B, which is used to fluidly couple the vent 201 of the vacuum adsorption heater 200 to the vacuum pump 300; and

[0094] ◆A third conduit C, connected to the second conduit B, is used to supply gas from the gas source 400 to the vacuum adsorption system. In some embodiments, the gas in the gas source 400 may be nitrogen, which is relatively inexpensive and less prone to chemical reactions. In other embodiments, other gases, such as helium, may also be used.

[0095] According to embodiments of this application, gas from the gas source 400 can be supplied to the vacuum adsorption system as needed during operation via a third conduit C fluidly coupled to the gas source 400. Therefore, when adsorbing wafers using this vacuum adsorption system, the adsorption conduit inside the heater (e.g., ...) can be easily adjusted during both adsorption and release of the wafers. Figure 12 The gas pressure in the through-hole 13 and through-hole 131 (shown in the diagram) is used to adjust the pressure difference between the back and front sides of the wafer, thereby adjusting the magnitude of the adsorption force. Needless to say, this will help meet various adsorption needs of the wafer. For example, when the wafer processing requires a large adsorption force, only a small amount of gas can be introduced from the gas source 400, or no gas can be introduced, to ensure that the vacuum adsorption system generates an adsorption force on the wafer; while in processes requiring a smaller adsorption force, a larger amount of gas can be introduced from the gas source 400 into the vacuum adsorption system to offset some of the adsorption force generated by the vacuum pump 300.

[0096] Another technical advantage of the third conduit C is that, during the wafer release process, gas can be introduced from the gas source 400 into the vacuum adsorption system, thereby supplying the gas to the adsorption conduit inside the heater. This causes the pressure on the back side of the wafer to rise rapidly to equal or even greater than the pressure on its front side, thus eliminating the adsorption force on the wafer in a short time and releasing it. Compared to existing technologies that rely solely on shutting down the vacuum adsorption system and allowing the gas in the reaction chamber to automatically flow to the back side of the wafer, this solution significantly improves operational efficiency.

[0097] The structure of a vacuum adsorption system according to some embodiments of this application is further described below.

[0098] See Figure 13 In the vacuum adsorption system, a throttling valve TV is installed on the first pipeline A to control the suction of gas in the reaction chamber 100 by the vacuum pump 300. In some embodiments, the gas pressure Pc in the reaction chamber 100 can be measured by a pressure measuring device 102 (e.g., a barometer or vacuum gauge). The throttling valve TV can be adjusted according to the gas pressure Pc in the reaction chamber 100 to control the gas flow rate in the first pipeline A, thereby controlling the gas pressure Pc in the reaction chamber 100 to reach the desired level.

[0099] like Figure 13As shown, a first valve CHCV-1 is installed on the second pipeline B near the vent 201, and a third pipeline C is connected downstream of the first valve CHCV-1 on the second pipeline B (i.e., closer to the vacuum pump 300). A second valve CHCV-2 is installed on the third pipeline C. In one embodiment, a pressure controller 401 is installed on the third pipeline C to regulate the flow rate of gas supplied to the vacuum adsorption system. As shown, the pressure controller 401 may include a mass flow controller MFM, an adjustable flow valve 402, and a pressure measuring device 403 (e.g., a barometer or vacuum gauge). Those skilled in the art will understand that the pressure controller 401 is not limited to the structure shown in the figure; existing pressure controllers or devices with similar functions can be used as the pressure controller 401.

[0100] See further Figure 13 The second pipeline B branches downstream of the first valve CHCV-1 into a first manifold B1 and a second manifold B2. The other end of the first manifold B1 is connected to the first pipeline A between the extraction port 101 of the reaction chamber 100 and the throttle valve TV. The third valve CHCV-3 is mounted on the first manifold B1. The other end of the second manifold B2 is connected to the vacuum pump 300. In one embodiment, the other end of the second manifold B2 may be connected to the first pipeline A between the vacuum pump 300 and the throttle valve TV. A fourth valve CHCV-4 is mounted on the second manifold B2. In one embodiment, a pressure measuring device 500 (e.g., a barometer or vacuum gauge) may also be mounted on the second manifold B2 to measure the pressure Pb in the second manifold B2, which reflects the pressure in the adsorption pipeline inside the heater.

[0101] In some embodiments, the first valve CHCV-1, the second valve CHCV-2, the third valve CHCV-3, and the fourth valve CHCV-4 are all electromagnetic pneumatic valves, which can be fully opened or closed as needed to control the on / off state of the corresponding pipelines. Using electromagnetic pneumatic valves allows for more precise control. In other embodiments, other types of valves may also be used.

[0102] This application also provides a method for adsorbing wafers using the aforementioned vacuum adsorption system. In short, in this method, during the adsorption and / or release of the wafer, gas from a gas source 400 can be supplied to the adsorption line inside the heater via a second line B and a third line C to adjust the pressure difference between the back and front sides of the wafer.

[0103] According to some embodiments of this application, during the wafer adsorption process, gas from gas source 400 can be supplied to the adsorption pipeline inside the heater using the second pipeline B and the third pipeline C, maintaining a required pressure difference between the back side and the front side of the wafer, for example, keeping the pressure on the back side of the wafer 30-150 Torr lower than the pressure on the front side. During the wafer release process, gas from gas source 400 can be supplied to the adsorption pipeline inside the heater using the second pipeline B and the third pipeline C, increasing the pressure on the back side of the wafer to be greater than or equal to the pressure on the front side, for example, increasing the pressure on the back side of the wafer to be 5-10 Torr higher than the pressure on the front side. At this point, the adsorption force is completely eliminated and there is a certain pushing force on the back side of the wafer, thus allowing the wafer to be easily moved to the next station.

[0104] In general, according to some embodiments of this application, the method for adsorbing wafers using the above-described vacuum adsorption system mainly includes the following steps:

[0105] (a) Wafer placement: With the vacuum adsorption system in the off state (i.e., both the second pipeline B and the third pipeline C are in the off state), place the wafer on the bearing surface of the vacuum adsorption heater 200 in the reaction chamber 100.

[0106] (b) Wafer Adsorption: The vacuum adsorption system is activated, and gas is continuously drawn from the adsorption pipe inside the vacuum adsorption heater 200 through the second pipe B, so that the pressure on the back side of the wafer is kept lower than the pressure on its front side, thereby adsorbing the wafer onto the supporting surface of the vacuum adsorption heater 200; and

[0107] (c) Releasing the wafer: After the wafer is processed, the gas in the adsorption pipeline inside the vacuum adsorption heater 200 is stopped, and the gas from the gas source 400 is supplied to the adsorption pipeline inside the vacuum adsorption heater 200 through the second pipeline B and the third pipeline C, so that the pressure on the back side of the wafer is increased to be equal to or greater than the pressure on its front side, so as to release the wafer.

[0108] In some embodiments, the above method may further include at least one of the following steps:

[0109] (a1) Prior to step (a), the supporting surface of the vacuum adsorption heater 200 is heated (e.g., heated to 450-500°C), and the reaction chamber 100 is evacuated to a vacuum state by the vacuum pump 300; and

[0110] (a2) After step (a) and before step (b), gas is injected into the reaction chamber 100 (through other pipelines, not shown in the figure) to increase the gas pressure Pc in the reaction chamber 100 (if necessary, Pc can be increased to 200-600 Torr, and the gas pressure above the throttle valve TV can reach 200 Torr).

[0111] In one embodiment of this application, in step (a2), step (b) begins when the gas pressure Pc in the reaction chamber 100 rises above a threshold (e.g., 100 Torr). In step (b), while the vacuum pump 300 continuously draws gas from the adsorption pipeline inside the vacuum adsorption heater 200 through the second pipeline B, gas from the gas source 400 is supplied to the adsorption pipeline inside the vacuum adsorption heater 200 through the second pipeline B and the third pipeline C, thereby keeping the pressure on the back side of the wafer 30-150 Torr lower than the pressure on its front side. The specific pressure difference can be adjusted according to the wafer adsorption requirements.

[0112] As previously described, a throttle valve TV is installed on the first pipeline A; a first valve CHCV-1 is installed on the second pipeline B near the vent 201; a third pipeline C is connected downstream of the first valve CHCV-1 on the second pipeline B, and a second valve CHCV-2 is installed on the third pipeline C; the second pipeline B branches downstream of the first valve CHCV-1 into a first manifold B1 and a second manifold B2; the other end of the first manifold B1 is connected to the first pipeline A between the vent 101 of the reaction chamber 100 and the throttle valve TV, and the third valve CHCV-3 is installed on the first manifold B1; the other end of the second manifold B2 is connected to the vacuum pump 300 (for example, connected to the first pipeline A between the vacuum pump 300 and the throttle valve TV, such as...). Figure 13 As shown in the diagram, the fourth valve, CHCV-4, is installed on the second manifold B2. The specific operating procedures of these valves and their corresponding pipelines are as follows:

[0113] In step (a1), the first valve CHCV-1, the second valve CHCV-2, the third valve CHCV-3, and the fourth valve CHCV-4 are all closed, and the throttle valve TV is open, so that only the first pipeline A is in the open state, thereby allowing the vacuum pump 300 to evacuate the reaction chamber 100 to a vacuum state. In steps (a) (i.e., placing the wafer) and (a2), these valves remain in this state.

[0114] In step (b) (i.e., adsorbing the wafer), the first valve CHCV-1, the second valve CHCV-2, and the fourth valve CHCV-4 are all open, while the third valve CHCV-3 is closed. The vacuum pump 300 continues to draw gas from the reaction chamber 100 through the first pipe A, maintaining the gas pressure Pc in the reaction chamber 100 at the required level (e.g., 200 Torr). At this time, the second pipe B, the second manifold B2, and the third pipe C are in a continuous state, thereby allowing the vacuum pump 300 to draw gas from the adsorption pipes inside the vacuum adsorption heater 200 (i.e., the gas on the back side of the wafer). Simultaneously, the gas source 400 can introduce gas into the vacuum adsorption system, and the amount of gas introduced (i.e., the gas flow rate in the third pipe C) can be controlled by adjusting the pressure controller 401. The combined effect of the gas drawn from the adsorption line of the vacuum adsorption heater 200 by the vacuum pump 300 through the second pipe B and the second manifold B2, and the gas introduced into the adsorption line by the gas source 400 through the third pipe C, maintains the pressure on the back side of the wafer 30-150 Torr lower than the pressure on the front side. The specific pressure difference can be set as needed.

[0115] In step (c) (i.e., releasing the wafer), the first valve CHCV-1, the second valve CHCV-2, and the third valve CHCV-3 are all open, while the fourth valve CHCV-4 is closed. The vacuum pump 300 continues to pump gas from the reaction chamber 100 through the first pipe A, maintaining the gas pressure Pc in the reaction chamber 100 at the required level (e.g., 200 Torr). At this time, on the one hand, the gas in the reaction chamber 100 can enter the adsorption pipe inside the vacuum adsorption heater through the first pipe A, the first manifold B1, and the second pipe B, thereby reaching the back side of the wafer. On the other hand, external gas (e.g., nitrogen) from the gas source 400 enters the adsorption pipe inside the vacuum adsorption heater through the third pipe C and the second pipe B, thereby reaching the back side of the wafer. Due to the interaction of these two gases, the pressure on the back side of the wafer rises rapidly, quickly reducing the pressure difference between it and the front side. Furthermore, the flow rate of the gas in the third pipeline C can be adjusted by regulating the gas pressure controller 401, causing the pressure on the back side of the wafer to rise to be equal to or greater than the pressure on the front side. For example, the pressure on the back side of the wafer can be increased to 5-10 Torr higher than the pressure on the front side, thereby rapidly eliminating the adsorption force and quickly releasing the wafer. Clearly, this operating method greatly improves operational efficiency.

[0116] The technical content and features of this application have been described in the above-mentioned embodiments; however, the above embodiments are merely examples for implementing this application. Those skilled in the art may still make various substitutions and modifications based on the teachings and disclosures of this application without departing from its spirit. Therefore, the disclosed embodiments of this application do not limit the scope of this application. Conversely, modifications and equivalent settings that do not depart from the spirit and scope of this application are all included within the scope of this application.

Claims

1. A vacuum adsorption system for adsorbing and releasing wafers on a support surface of a vacuum adsorption heater (200) located within a reaction chamber (100), the reaction chamber (100) having an extraction port (101) and the vacuum adsorption heater (200) having a vent (201), the system comprising: A first conduit (A) is used to fluidly couple the evacuation port (101) of the reaction chamber (100) to the vacuum pump (300); The second conduit (B) is used to fluidly couple the vent (201) of the vacuum adsorption heater (200) to the vacuum pump (300); and A third conduit (C), which is connected to the second conduit (B) and is used at least to supply gas from a gas source (400) to the vacuum adsorption system during wafer adsorption, is provided with a pressure controller (401) for regulating the flow rate of gas supplied to the vacuum adsorption system so that the pressure on the back side of the wafer is kept at least 30-150 Torr lower than the pressure on the front side during wafer adsorption.

2. The vacuum adsorption system according to claim 1, wherein a first valve (CHCV-1) is disposed on the second pipeline (B) near the air inlet (201), and the third pipeline (C) is connected downstream of the first valve (CHCV-1) on the second pipeline (B).

3. The vacuum adsorption system according to claim 2, wherein a second valve (CHCV-2) is installed on the third pipeline (C).

4. The vacuum adsorption system according to claim 3, wherein the pressure controller (401) includes a mass flow controller (MFM), an adjustable flow valve (402), and a first pressure measuring device (403).

5. The vacuum adsorption system according to claim 3, wherein: A throttle valve (TV) is installed on the first pipeline (A); The second pipeline (B) branches into a first manifold (B1) and a second manifold (B2) downstream of the first valve (CHCV-1). The other end of the first manifold (B1) is connected to the first pipeline (A) between the air extraction port (101) of the reaction chamber (100) and the throttle valve (TV), and the third valve (CHCV-3) is installed on the first manifold (B1); The other end of the second manifold (B2) is connected to the vacuum pump (300), and the fourth valve (CHCV-4) is mounted on the second manifold (B2).

6. The vacuum adsorption system according to claim 5, wherein a second pressure measuring device (500) is further disposed on the second manifold (B2).

7. The vacuum adsorption system according to claim 5, wherein the first valve (CHCV-1), the second valve (CHCV-2), the third valve (CHCV-3) and the fourth valve (CHCV-4) are all electromagnetic pneumatic valves.

8. A method for adsorbing wafers using the vacuum adsorption system according to claim 1, comprising: During the adsorption and / or release of the wafer, gas from the gas source (400) is supplied to the adsorption line inside the vacuum adsorption heater (200) using the second line (B) and the third line (C) to adjust the pressure difference between the back and front sides of the wafer, wherein the adsorption line is in fluid communication with the vent (201).

9. The method according to claim 8, wherein: During the adsorption process of the wafer, gas from the gas source (400) is supplied to the adsorption pipeline through the second pipeline (B) and the third pipeline (C) so that the pressure on the back side of the wafer is kept 30-150 Torr lower than the pressure on its front side.

10. The method according to claim 8, wherein: During the release of the wafer, gas from the gas source (400) is supplied to the adsorption line using the second line (B) and the third line (C), causing the pressure on the back side of the wafer to rise to a level greater than or equal to the pressure on its front side.

11. The method according to claim 8, wherein: During the release of the wafer, gas from the gas source (400) is supplied to the adsorption line using the second line (B) and the third line (C), causing the pressure on the back side of the wafer to increase to 5-10 Torr greater than the pressure on its front side.

12. A method for adsorbing wafers using the vacuum adsorption system according to claim 1, comprising the following steps: (a) Placing the wafer: With the vacuum adsorption system in the off state, the wafer is placed on the bearing surface of the vacuum adsorption heater (200) in the reaction chamber (100); (b) Adsorbing the wafer: The vacuum adsorption system is activated, and gas is continuously drawn from the adsorption pipe inside the vacuum adsorption heater (200) through the second pipe (B), so that the pressure on the back side of the wafer is kept lower than the pressure on its front side, thereby adsorbing the wafer onto the bearing surface of the vacuum adsorption heater (200), wherein the adsorption pipe is in fluid communication with the vent (201); and (c) Releasing the wafer: After the wafer has been processed, the gas in the adsorption line inside the vacuum adsorption heater (200) is stopped, and gas from the gas source (400) is supplied to the adsorption line using the second line (B) and the third line (C) so that the pressure on the back side of the wafer is increased to be equal to or greater than the pressure on its front side, thereby releasing the wafer.

13. The method of claim 12, further comprising at least one of the following steps: (a1) Prior to step (a), the supporting surface of the vacuum adsorption heater (200) is heated, and the reaction chamber (100) is evacuated to a vacuum state by the vacuum pump (300); and (a2) After step (a) and before step (b), gas is injected into the reaction chamber (100) to increase the gas pressure (Pc) in the reaction chamber (100).

14. The method of claim 13, wherein: In step (a2), step (b) begins when the gas pressure (Pc) in the reaction chamber (100) rises above a threshold.

15. The method of claim 14, wherein the threshold is 100 Torr.

16. The method of claim 12, wherein: In step (b), while the vacuum pump (300) continuously draws gas from the adsorption line in the vacuum adsorption heater (200) through the second line (B), gas from the gas source (400) is supplied to the adsorption line through the second line (B) and the third line (C), thereby keeping the pressure on the back side of the wafer 30-150 Torr lower than the pressure on its front side.

17. The method according to claim 12, wherein: A throttle valve (TV) is installed on the first pipeline (A); A first valve (CHCV-1) is installed on the second pipeline (B) near the vent (201). The third pipeline (C) is connected downstream of the first valve (CHCV-1) on the second pipeline (B), and a second valve (CHCV-2) is installed on the third pipeline (C). The second pipeline (B) branches into a first manifold (B1) and a second manifold (B2) downstream of the first valve (CHCV-1). The other end of the first manifold (B1) is connected to the first pipeline (A) between the vent (101) of the reaction chamber (100) and the throttle valve (TV), and the third valve (CHCV-3) is installed on the first manifold (B1); and The other end of the second manifold (B2) is connected to the vacuum pump (300), and the fourth valve (CHCV-4) is mounted on the second manifold (B2).

18. The method of claim 17, wherein: During step (a), the first valve (CHCV-1), the second valve (CHCV-2), the third valve (CHCV-3), and the fourth valve (CHCV-4) are all closed, and the throttle valve (TV) is open.

19. The method of claim 17, wherein: During step (b), the first valve (CHCV-1), the second valve (CHCV-2), and the fourth valve (CHCV-4) are all open, and the third valve (CHCV-3) is closed.

20. The method of claim 19, wherein: In step (b), the flow rate of the gas in the third pipeline (C) is adjusted so that the pressure on the back side of the wafer is kept 30-150 Torr lower than the pressure on the front side.

21. The method of claim 17, wherein: During step (c), the first valve (CHCV-1), the second valve (CHCV-2), and the third valve (CHCV-3) are all open, and the fourth valve (CHCV-4) is closed.

22. The method of claim 21, wherein: In step (c), the flow rate of the gas in the third pipeline (C) is adjusted so that the pressure on the back side of the wafer is increased to be equal to or greater than the pressure on its front side.

23. The method according to claim 22, wherein: In step (c), the flow rate of the gas in the third pipeline (C) is adjusted so that the pressure on the back side of the wafer is increased to 5-10 Torr greater than the pressure on the front side.

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