WO2023116159A1

WO2023116159A1 - Vacuum adsorption system and method

Info

Publication number: WO2023116159A1
Application number: PCT/CN2022/126486
Authority: WO
Inventors: 张亚新; 荒见淳一
Original assignee: 拓荆科技股份有限公司
Priority date: 2021-12-22
Filing date: 2022-10-20
Publication date: 2023-06-29
Also published as: TW202335137A; CN116387224A

Abstract

The present application relates to a vacuum adsorption system and method. The vacuum adsorption system is used for adsorbing and releasing a wafer located on a bearing surface of a vacuum adsorption type heater in a reaction chamber; the reaction chamber is provided with an air extraction opening; and the vacuum adsorption type heater is provided with an air ventilation opening. The vacuum adsorption system comprises: a first pipeline used for fluidly coupling the air extraction opening of the reaction chamber to a vacuum pump; a second pipeline used for fluidly coupling the air ventilation opening of the vacuum adsorption type heater to the vacuum pump; and a third pipeline connected to the second pipeline and used for supplying a gas from a gas source to the vacuum adsorption system. When the vacuum adsorption system is used for adsorbing the wafer, the air pressure in an adsorption pipeline inside the heater can be conveniently adjusted in the process of adsorbing and releasing the wafer, thereby adjusting the pressure difference between the back surface and the front surface of the wafer, and facilitating the improvement of the operation efficiency.

Description

Vacuum adsorption system and method

technical field

The present application relates to a device for heating a wafer in a semiconductor processing chamber, in particular to a vacuum adsorption heater. The present application also relates to a vacuum adsorption system that can be used in conjunction with a vacuum adsorption heater, and a method for adsorbing a wafer by using the vacuum adsorption system.

Background technique

Wafers or substrates are the bases used to fabricate semiconductor devices. In order to prepare semiconductor devices (such as integrated circuits, semiconductor light-emitting devices, etc.), it is necessary to place the wafer or substrate in a semiconductor processing chamber (also called a reaction chamber) for heating and deposition processing (such as chemical vapor deposition (CVD), plasma Volume Enhanced Chemical Vapor Deposition (PECVD), etc.) to deposit thin films on the surface of wafers or substrates. During the processing, the wafer can be fixed on the heater in the processing chamber by means of vacuum adsorption or the like.

However, the existing vacuum adsorption heaters, vacuum adsorption systems and adsorption methods have many disadvantages.

For example, the wafer-carrying surface of the heater is in surface contact with the wafer, and uneven contact is likely to occur. For example, due to the surface roughness of the carrying surface and the wafer itself and its processing errors, when the wafer is placed on the carrying surface, the two may not be completely and evenly bonded, and some positions may be suspended or in different positions. There are uneven gaps in the location.

In this case, on the one hand, it may lead to uneven heating of the various positions of the wafer when the heater is heated, so that the heating effect is not good, and even affects the yield of the wafer; The vacuum adsorption force of the wafer is not enough, and the adsorption effect is not good; even the wafer may move on the carrying surface, especially in the processing chamber with large air flow and high pressure, the possibility of wafer movement is greater.

In addition, the vacuum adsorption structure on some vacuum adsorption heaters (such as the through hole on the heating plate, the adsorption pipeline inside the heating plate, etc.) is not easy to process due to its small size, deep depth, etc., and the processing is difficult , Higher processing costs.

In addition, the existing vacuum adsorption system generally only uses a vacuum pump to suck the gas (air) in the adsorption pipeline inside the heater, thereby controlling the back surface of the wafer (that is, the surface in contact with the wafer carrying surface of the heater). ) and the pressure difference between the front side, so in the process of absorbing and releasing the wafer, only by operating the vacuum pump (or the valve on the vacuum pump line) to control the air pressure in the adsorption line inside the heater, so as to control the back side of the wafer The pressure difference to the front side thereby controls the suction force on the wafer. However, this method is very inconvenient (or even impossible) to adjust the adsorption force to the wafer as needed; and, in the process of releasing the wafer, the only way to close the vacuum pump (or the valve on the vacuum pump pipeline) and let the reaction chamber The gas in the chamber automatically flows into the adsorption pipeline inside the heater to the back of the wafer, so that the pressure on the back of the wafer is roughly the same as the pressure on the front, thereby releasing the wafer. This whole process takes a long time, thus reducing the work efficiency.

Therefore, it is necessary to improve the vacuum adsorption heater, the vacuum adsorption system and the method for absorbing wafers by using the vacuum adsorption system in the prior art, so as to solve the above technical problems.

Contents of the invention

The purpose of this application is to solve at least one of the above-mentioned problems in the prior art, and to provide an improved vacuum adsorption heater. The heater can make uniform point contact between the wafer placed on the carrying surface and the carrying surface, so that it can not only effectively absorb the wafer during operation, but also prevent the wafer from moving on the heater carrying surface (even if It is in a reaction chamber with large air flow and high pressure), and makes the whole wafer evenly heated, thus improving the product quality of the wafer.

At the same time, the application also provides a vacuum adsorption system. When the vacuum adsorption system is used to adsorb wafers, the air pressure in the adsorption pipeline inside the heater can be conveniently adjusted during the process of absorbing and releasing wafers, thereby adjusting The pressure difference between the back and the front of the wafer (that is, to adjust the size of the adsorption force) can not only meet the various adsorption needs of the wafer (for example, some processing processes of the wafer require a larger adsorption force, while some processes require a smaller adsorption force). Adsorption force), and in the process of releasing the wafer, gas can be introduced to make the pressure on the back of the wafer rise rapidly to be equal to or even greater than the pressure on the front side, so that the adsorption force can be eliminated in a short time to release the wafer, which is beneficial Improve work efficiency.

The present application also provides a method for absorbing wafers by using the above-mentioned vacuum adsorption system. The method can effectively achieve the purpose of adjusting the adsorption force for absorbing wafers, thus having a wide range of applications and helping to improve the operation efficiency of wafer processing.

Some embodiments of the present application provide a vacuum adsorption system for adsorbing and releasing a wafer located on a carrying surface of a vacuum adsorption heater in a reaction chamber, the reaction chamber has a suction port, and the The vacuum adsorption heater has a vent, and the system includes: a first pipeline for fluidly coupling the suction port of the reaction chamber with a vacuum pump; a second pipeline for fluidly coupling the vacuum adsorption heater a heater vent fluidly coupled to the vacuum pump; and a third line connected to the second line and for supplying gas from a gas source to the vacuum adsorption system.

In some embodiments of the present application, a first valve is arranged on the second pipeline close to the air vent, and the third pipeline is connected to the downstream of the first valve on the second pipeline.

In some embodiments of the present application, a second valve is arranged on the third pipeline.

In one embodiment, an air pressure controller is further arranged on the third pipeline, which is used to adjust the flow rate of the gas supplied to the vacuum adsorption system. The air pressure controller may include a mass flow controller, an adjustable flow valve, and an air pressure measurement device.

In one embodiment, a throttling valve is arranged on the first pipeline; the second pipeline is branched into a first manifold pipeline and a second manifold pipeline downstream of the first valve; The other end of a manifold is connected to the first pipeline between the suction port of the reaction chamber and the throttle valve, and the third valve is arranged on the first manifold; the The other end of the second manifold is connected to the vacuum pump, and the fourth valve is arranged on the second manifold.

In one embodiment, an air pressure measuring device is further arranged on the second manifold.

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

Some embodiments of the present application also provide a method for absorbing a wafer by using the vacuum adsorption system according to any embodiment of the present application, which includes: during the process of absorbing and/or releasing the wafer, using The second pipeline and the third pipeline supply the gas from the gas source to the adsorption pipeline inside the vacuum adsorption heater to adjust the pressure difference between the backside and frontside of the wafer , wherein the sorption line is in fluid communication with the vent.

In some embodiments of the present application, during the process of adsorbing the wafer, the second pipeline and the third pipeline are used to supply the gas from the gas source to the adsorption pipeline, so that The pressure on the back side of the wafer is kept 30-150 Torr less than the pressure on the front side.

In some embodiments of the present application, during the process of releasing the wafer, the second pipeline and the third pipeline are used to supply the gas from the gas source to the adsorption pipeline, so that The pressure on the back side of the wafer is raised to be greater than or equal to the pressure on the front side. For example, the pressure on the back side of the wafer is increased to 5-10 Torr greater than the pressure on the front side.

Some embodiments of the present application provide a method of using the vacuum adsorption system according to any embodiment of the present application to adsorb a wafer, which includes the following steps:

(a) placing the wafer: when the vacuum adsorption system is in a closed state, placing the wafer on the carrying surface of the vacuum adsorption heater in the reaction chamber;

(b) Adsorb the wafer: start the vacuum adsorption system, continuously suck the gas in the adsorption pipeline inside the vacuum adsorption heater through the second pipeline, and make the back side of the wafer maintaining a pressure less than the pressure at its face, thereby adsorbing the wafer onto the loading surface of the vacuum adsorption heater, wherein the adsorption line is in fluid communication with the vent; and

(c) releasing the wafer: after the processing of the wafer is completed, stop sucking the gas in the adsorption pipeline inside the vacuum adsorption heater, and use the second pipeline and the first Three lines supply the gas from the gas source to the adsorption line so that the pressure on the backside of the wafer is raised to be equal to or greater than the pressure on the front side thereof to release the wafer.

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

(a1) prior to step (a), heating the load bearing surface of the vacuum adsorption heater (eg,

heating to 450-500°C), and pumping the reaction chamber to a vacuum state by the vacuum pump; and

(a2) After the step (a) and before the step (b), inject gas into the reaction chamber to increase the air pressure in the reaction chamber.

In some embodiments, in step (a2), step (b) starts when the gas pressure in the reaction chamber rises above a threshold (eg, 100 Torr).

In some embodiments, in step (b), while using the vacuum pump to continuously pump the gas in the adsorption pipeline in the vacuum adsorption heater through the second pipeline, through The second pipeline and the third pipeline supply gas from the gas source into the adsorption pipeline so that the pressure on the back side of the wafer is kept 30-150 Torr lower than the gas pressure on the front side of the wafer .

As mentioned above, in some embodiments of the present application, a throttling valve is arranged on the first pipeline; a first valve is arranged on the second pipeline near the vent; the third pipeline connected to the downstream of the first valve on the second pipeline, and a second valve is arranged on the third pipeline; the second pipeline is branched into a first branch downstream of the first valve pipeline and a second manifold; the other end of the first manifold is connected to the first pipeline between the suction port of the reaction chamber and the throttle valve, and the third valve It is arranged on the first manifold; and the other end of the second manifold is connected to the vacuum pump, and the fourth valve is arranged on the second manifold.

In some embodiments, during the execution of step (a1), the first valve, the second valve, the third valve, and the fourth valve are all closed, and the throttle valve is opened.

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.

In some embodiments, in step (b), the flow rate of the gas in the third pipeline (C) is adjusted so that the air pressure at the back of the wafer is kept 30-150 Torr lower than the air pressure at the front of the wafer.

In some embodiments, during the execution of the step (c), the first valve, the second valve and the third valve are all opened, and the fourth valve is closed.

In some embodiments, in step (c), the flow rate of the gas in the third pipeline 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 the front side. For example, the flow rate of the gas in the third pipeline (C) is adjusted so that the pressure on the backside of the wafer is increased to be 5-10 Torr higher than the pressure on the front side.

Description of drawings

In order to more clearly illustrate the specific implementation manners of the present application and the resulting technical effects, the specific embodiments of the present application will be described below in conjunction with the accompanying drawings. For the sake of clarity and convenience of drawing layout, the drawings are not all drawn to scale, for example, some drawings are exaggerated to show local details, while others are shrunk to show the overall structure. In the interest of clarity, the drawings may not show all components of a given device or device. Finally, the same reference numerals are used to refer to the same features throughout the specification and drawings. in:

FIG. 1 is a schematic perspective view of the overall structure of a vacuum adsorption heater according to some embodiments of the present application;

2 is a top view of the heating plate of the vacuum adsorption heater shown in FIG. 1, which more clearly shows the grooves and protrusions in the upper surface (ie, the surface for carrying the wafer) of the main body of the heating plate. The first distribution of points;

Fig. 2A is an enlarged view at A of Fig. 2, which particularly shows that the through hole on the heating plate is located in the innermost annular groove, and the diameter is greater than the width of the annular groove;

Fig. 3 is similar to Fig. 2, and it is also a top view of the heating plate, showing a second distribution of grooves and bumps in the upper surface of the heating plate;

Fig. 4 is also similar to Fig. 2, which is also a top view of the heating plate, showing a third distribution mode of grooves and bumps in the upper surface of the heating plate;

Figure 5 is also similar to Figure 2, which is also a top view of the heating plate, showing a fourth distribution of grooves and bumps in the upper surface of the heating plate;

Fig. 6 is also similar to Fig. 2, which is also a top view of the heating plate, showing a fifth distribution of grooves and bumps in the upper surface of the heating plate;

Fig. 7 is also similar to Fig. 2, which is also a top view of the heating plate, showing a sixth distribution mode of grooves and bumps in the upper surface of the heating plate;

Fig. 8 is also similar to Fig. 2, which is also a top view of the heating plate, showing the seventh distribution of grooves and bumps in the upper surface of the heating plate;

Fig. 9 is a front view of the vacuum adsorption heater shown in Fig. 1, which shows the front structure of the vacuum adsorption heater;

Fig. 10 is a B-B cross-sectional view of Fig. 9, which shows the internal structure of the vacuum adsorption heater at the cross-sectional position;

Fig. 11 is a left side view of the vacuum adsorption heater shown in Fig. 1, which shows the structure of the side of the heater;

Figure 12 is a C-C cross-sectional view of Figure 11, which shows the internal structure of the vacuum adsorption heater at the cross-sectional position;

FIG. 12A is an enlarged view of D in FIG. 12, which generally schematically shows the structure of bumps, grooves, and through holes in the vertical direction; and

Fig. 13 is a schematic structural diagram of a vacuum adsorption system according to some embodiments of the present application.

Detailed ways

Embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. Aspects of the present application may be understood more readily by reading the following description of specific embodiments with reference to the accompanying drawings. It should be noted that these embodiments are only exemplary, which are only used to explain and illustrate the technical solutions of the present application, rather than limiting the present application. Based on these embodiments, those skilled in the art can make various modifications and transformations (such as changing the size and/or layout of the grooves and bumps on the upper surface of the main body of the heating plate, etc.). All technical solutions obtained by transformation in an equivalent manner belong to the protection scope of the present application.

The names of various components used in this manual are for the purpose of illustration only, and do not have a limiting effect. Different manufacturers may use different names to refer to components with the same function.

Vacuum adsorption heater

Fig. 1 is a schematic perspective view of the overall structure of a vacuum adsorption heater according to an embodiment of the present application. As shown in FIG. 1 , the vacuum adsorption heater mainly includes a heating plate 10 . The heating plate 10 includes a generally plate-shaped main body 1 and a support shaft 2 located below the main body 1 .

As shown in FIG. 1 , the main body 1 has an upper surface 11 for carrying a wafer. During the working process, the main body 1 of the heating plate 10 is located in a reaction chamber, and the wafer (not shown in the figure) can be placed on the upper surface 11 of the main body 1 by a transfer device such as a manipulator, and then sucked by vacuum. fixed. After the wafer is fixed, it can be subjected to operations such as deposition processing.

Referring to FIG. 1 in combination with FIGS. 9-12 , in some embodiments of the present application, the main body 1 of the heating plate 10 and the support shaft 2 located below the main body 1 are formed as one body. For example, both can be made of ceramics, and then they can be integrated into one body by means of adhesion or welding. Compared with the heating plate adopting a split structure (that is, the main body and the support shaft are assembled together in a detachable manner), this integrated structure in the present application not only saves the steps of fixing and sealing the two , and the sealing element between the two is also omitted, and the sealing performance is greatly improved, thus effectively improving the effect of vacuum adsorption.

Continuing to refer to Fig. 1 and Fig. 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 cooling block 50 located outside the cooling block 50 and clamped The fixed block 60 of the cooling block 50 . The fixing block 60 is used to fix the vacuum adsorption heater on the machine platform. The specific structures of the cooling block 50 and the fixing block 60 can adopt designs known in the art, and will not be repeated here.

As far as the internal structure is concerned, the vacuum adsorption heater further includes a heating element (not shown in the figure) 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, resistive wire. The heating rod 40 may comprise a material with good electrical conductivity, such as copper, nickel, and the like. The heating element, the heating rod 40 and the electrical connections between them can all adopt designs known in the art, which will not be repeated here.

As shown in FIGS. 10 and 12 , the support shaft 2 is a hollow structure, inside which can accommodate a plurality of sequentially stacked quartz blocks 20 and/or polyether ether ketone (PEEK) blocks 30 . The heating rod 40 is located inside the support shaft 2 and runs through the quartz block 20 and/or the PEEK block 30, and can be electrically connected to an external power source. When the power is turned on, the heating element will generate heat and transfer the heat to the wafer on the main body 1 of the heating plate 10 . The heating rod 40 also generates heat. The quartz block 20 and PEEK block 30 surrounding the heating rod 40 help to maintain little or no heat loss inside the support shaft 2, thereby helping to transfer heat to the wafer for heating it. The quartz block 20 and the PEEK block 30 are also used to achieve electrical insulation between components inside the support shaft 2 .

In this application, the structure of the main body 1 of the heating plate 10 (especially the upper surface 11 carrying the wafer) is specially designed. The details are as follows.

Referring to FIG. 1 , FIG. 2 and FIG. 2A , FIG. 2 is a top view of the heating plate 10 shown in FIG. 1 , and FIG. 2A is an enlarged view of A in FIG. 2 . In the present application, the main body 1 of the heating plate 10 further has the following structure:

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

◆ one or more through holes 13 in fluid communication with at least one groove 12; and

◆ A plurality of bumps 14 on the upper surface 11 for supporting the wafer.

In some embodiments given in the present application, the plurality of grooves 12 and the plurality of protrusions 14 are substantially evenly distributed on the upper surface 11 . Those skilled in the art understand that the plurality of grooves 12 and the plurality of bumps 14 may not be evenly distributed, or one of them may be evenly distributed. For example, in some embodiments, the plurality of grooves 12 are substantially evenly distributed, while the plurality of bumps 14 are unevenly distributed (for example, the bumps in the middle part are denser, while the surrounding bumps are sparser); In the embodiment, the protrusions 14 are generally evenly distributed, while the grooves 12 are unevenly distributed (for example, the closer to the middle, the denser the grooves, and the farther to the outer periphery, the sparser the grooves).

Different from the prior art, in this application, since the upper surface 11 has bumps 14, the wafer and the upper surface 11 of the main body of the heating plate can form a uniform point contact, and there can be a uniform gap between the two, that is, These bumps 14 make the contact between the wafer and its carrying surface (that is, the upper surface 11 of the main body 1) more uniform, thus helping to make each part of the wafer receive uniform adsorption force and uniform heating, thereby facilitating the wafer. Round processing helps to ensure the quality of film formation on the surface of the wafer and improve its pass rate.

In some embodiments of the present application, as shown in FIGS. 1 and 2 , the plurality of grooves 12 includes a plurality of annular grooves 121 arranged in concentric circles and radial grooves 122 connecting the annular grooves 121 in fluid communication. . In one embodiment, all radial grooves 122 are in fluid communication with adjacent annular grooves 121 such that all annular grooves 121 and radial grooves 122 are in fluid communication. Thus, all grooves 12 are in full fluid communication. Therefore, all the grooves 12 can be vacuumed by vacuuming one groove 12 , so as to provide a suction force for the wafer.

In some embodiments of the present application, the width of the annular groove 121 and the radial groove 122 are both 0.5-1.5mm, and the depth is less than or equal to 1.0mm; the distance between adjacent annular grooves 121 is 10- 50mm. More preferably, the width of the annular groove 121 and the radial groove 122 are both 0.5-1.0 mm, and the depth is less than or equal to 0.5 mm; the distance between adjacent annular grooves 121 is 15-50 mm. The grooves with the above-mentioned size range are not only convenient for processing, but also help to effectively realize the adsorption of the wafer. The figures of the present application show a certain number of annular grooves 121 and radial grooves 122 for illustrative purposes only. It should be appreciated that the heating plate 10 may have any suitable number of annular grooves 121 and radial grooves 122 .

Further, as shown in FIGS. 2 and 2A, in some embodiments of the present application, the main body 1 may only include one through hole 13, and the through hole 13 is located at one groove 12, such as the innermost annular groove. 121, thus in fluid communication with the annular groove 121, as shown in Figure 2A. In other embodiments, the through hole 13 can also be located at other grooves 12 . In addition, as shown in FIG. 2A , the diameter of the through hole 13 is larger than the width of the groove 12 , for example, 0.8-1.8 mm. Since the through hole is deep, the through hole 13 with a diameter within this size range is easy to process and can achieve a good adsorption effect. Setting only one through hole 13 also simplifies the processing technology and saves the processing cost. In other embodiments, a plurality of through holes 13 may also be provided on the main body 1 .

In some embodiments of the present application, as shown in the figure, each bump 14 may be substantially circular, but the present application is not limited thereto. When manufacturing the main body 10 of the heating plate 1 , the bumps 14 can be directly sintered and formed on 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 distance between adjacent bumps 14 is 3-20 mm. The bumps with this size range are not only convenient for processing and shaping (such as facilitating the design of the mold of the main body 1 of the heating plate 10 ), but also 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 distance between adjacent bumps 14 is 5-15 mm. Bumps with this size range are more conducive to their production processing and also help to provide uniform contact with the wafer.

In order to achieve a better technical effect, 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 distribution of the grooves 12 and the distribution of the bumps 14, and several exemplary ones will be described below in conjunction with the accompanying drawings. scheme. It should be understood that the distribution manners of the grooves 12 and bumps 14 are not limited to these schemes.

In the first type of solution, as shown in FIGS. 2-4 , the upper surface 11 of the main body 1 includes seven annular grooves 121 in total. Both the annular groove 121 and the radial groove 122 have a width of 1.0mm and a depth of 0.5mm; and the distance between adjacent annular grooves 121 is 21.5mm. In this type of solution, the annular grooves 121 are relatively dense, so that the adsorption force is more uniform during the working process, and the adsorption effect on the wafer is good.

In the first embodiment of this type of scheme, as shown in Figure 2, the diameter of each bump 14 is 2.0mm, and the height is 0.1mm; and a plurality of bumps 14 are distributed along the circumference, thereby forming a plurality of concentric For a circle, the distance between adjacent bumps 14 on the same circumference and between adjacent circumferences is 7 mm. This structure helps to achieve uniform support of the wafer from the circumference.

In the second embodiment of this type of scheme, as shown in Figure 3, the diameter of each bump 14 is 2.0mm, and the height is 0.1mm; Three bumps 14 can form an equilateral triangle), and the distance between adjacent bumps 14 is 10 mm.

In a third embodiment of this type of scheme, as shown in Figure 4, the diameter of each bump 14 is 2.0mm, and the height is 0.1mm; and a plurality of bumps 14 are distributed in a triangle (for example, the nearest Three bumps 14 can form an equilateral triangle), and the distance between adjacent bumps 14 is 5mm.

In the second type of solution, as shown in FIGS. 5-8 , the upper surface 11 of the main body 1 includes four annular grooves 121 in total. Both the annular groove 121 and the radial groove 122 have a width of 1.0 mm and a depth of 0.5 mm; and the distance between adjacent annular grooves 121 is 43 mm. In this type of solution, the annular grooves 121 are relatively sparse, and the heating plate 10 with such a structure is more convenient for production and processing, and the mold design and manufacture are more convenient, thus reducing the production cost.

In the first embodiment of this type of solution, as shown in Figure 5, the diameter of each bump 14 is 2.0mm, and the height is 0.1mm; and a plurality of bumps 14 are distributed along the circumference, thereby forming a plurality of concentric For a circle, the distance between adjacent bumps 14 on the same circumference and between adjacent circumferences is 7 mm. This structure helps to achieve uniform support of the wafer from the circumference.

In the second embodiment of this type of solution, as shown in Figure 6, the diameter of each bump 14 is 2.0mm, and the height is 0.1mm; and a plurality of bumps 14 are distributed along the circumference, thereby forming a plurality of concentric For a circle, the distance between adjacent bumps 14 on the same circumference and between adjacent circumferences is 15 mm. In this structure, the bumps 14 are more sparse, thus facilitating processing.

In a third embodiment of this type of scheme, as shown in Figure 7, the diameter of each bump 14 is 2.0mm, and the height is 0.1mm; and a plurality of bumps 14 are distributed in a triangle (for example, the nearest Three bumps 14 can form an equilateral triangle), and the distance between adjacent bumps 14 is 10mm.

In the fourth embodiment of this type of scheme, as shown in Figure 8, the diameter of each bump 14 is 2.0mm, and the height is 0.1mm; and a plurality of bumps 14 are triangular distribution (for example, the nearest Three bumps 14 can form an equilateral triangle), and the distance between adjacent bumps 14 is 5mm.

Those skilled in the art can understand: the spacing between adjacent annular grooves 121 is the distance between the corresponding points of two annular grooves, that is, the outermost edge (or centerline or innermost edge) of an annular groove 121 edge) and the corresponding point on the outermost edge (or centerline or innermost edge) of another annular groove 121. The width of a 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 distance between adjacent bumps 14 also refers to the distance between corresponding points on two bumps 14 (eg, the centers of the bumps).

Further referring to FIG. 12 and FIG. 12A, FIG. 12 is a cross-sectional view showing part of the internal structure of the vacuum adsorption heater, and FIG. 12A is an enlarged view at D of FIG. The structure of point 14, groove 12, and through hole 13 in the vertical direction. As shown in FIG. 12A , 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 may be 0.8-1.8 mm. Such size design is not only helpful to the processing of the through hole 13, but also helpful to achieve a good adsorption effect.

As shown in Figure 12, the vacuum adsorption heater also includes a through hole 131 that runs through 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 connected during operation. Coupled to a vacuum pump, the vacuum pump can suck the gas in the groove 12 through the pipeline and the through

holes

131 and 13, so as to generate a pressure difference between the back and front of the wafer, thereby absorbing 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. The through hole with this depth and diameter is convenient for processing and production.

In order to improve the adsorption effect, as shown in Figure 12, 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, preventing or reducing gas Give way.

In addition, as shown in FIG. 12 , the vacuum adsorption heater further includes a sealing ring 15 located between the heating rod 40 and the quartz block 20 and/or the PEEK block 30 . The sealing ring 15 is sleeved on the heating rod 40 and clamped between adjacent quartz blocks 20 and/or PEEK blocks 30 , so it can be firmly fixed.

Vacuum adsorption system and method for adsorbing wafers

The vacuum adsorption system provided according to the present application and the method for adsorbing wafers by using the vacuum adsorption system are introduced below. The vacuum adsorption system can be used in conjunction with the vacuum adsorption heater described in this specification, and can also be used in conjunction with vacuum adsorption heaters with other structures to adsorb wafers.

Referring to FIG. 13 , it schematically shows a vacuum adsorption system according to an embodiment of the present application. This system is used to adsorb and release wafers (in the figure) on the loading surface of the vacuum adsorption heater 200 (for example, the upper surface 11 of the main body 1 of the heating plate 10 shown in FIG. 1 ) in the reaction chamber 100. not shown). The reaction chamber 100 has a pumping port 101; the vacuum adsorption heater 200 has a vent 201 (for example, the vent 201 may be in fluid communication with the through hole 131 shown in FIG. 12). Although the figure shows that the entire vacuum adsorption heater 200 is located in the reaction chamber 100, in actual products, only a part of the vacuum adsorption heater 200, such as the main body 1 and the heating plate 10 shown in FIG. A part of the support shaft 2 (for example, the part above the cooling block 50 (including the cooling block 50 )) is located in the reaction chamber 100 .

As shown in Figure 13, the vacuum adsorption system includes:

◆The first pipeline A, which is used to fluidly couple the pumping port 101 of the reaction chamber 100 with the vacuum pump 300;

◆The second pipeline B, which is used to fluidly couple the vent 201 of the vacuum adsorption heater 200 with the vacuum pump 300; and

◆ A third line C, which is connected to the second line B and used to supply the 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 cheap and less prone to chemical reactions. In other embodiments, other gases, such as helium, may also be used.

According to the embodiment of the present application, the gas in the gas source 400 can be supplied to the vacuum adsorption system as needed during operation by means of the third pipeline C fluidly coupled with the gas source 400 . Therefore, when using the vacuum adsorption system to adsorb wafers, the adsorption pipeline inside the heater (for example, the through hole 13 and the through hole 131 shown in FIG. 12 ) can be easily adjusted during the process of absorbing and releasing the wafer. The air pressure in the wafer can be used to adjust the pressure difference between the back and the front of the wafer, so as to achieve the purpose of adjusting the size of the adsorption force. It goes without saying that this will help meet the various adsorption needs of the wafer. For example, when the processing technology of the wafer 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 produces an adsorption force to the wafer; In a process with a small adsorption force, a larger amount of gas can be introduced into the vacuum adsorption system from the gas source 400 to offset part of the adsorption force generated by the vacuum pump 300 .

Another technical effect produced by setting the third pipeline C is: during the process of releasing the wafer, gas can be introduced into the vacuum adsorption system from the gas source 400, thereby supplying the gas to the adsorption pipeline inside the heater , so that the pressure on the back of the wafer rises rapidly to be equal to or even greater than the pressure on the front, so that the adsorption force on the wafer can be eliminated in a short time, thereby releasing the wafer. Compared with the solution in the prior art that only relies on turning off the vacuum adsorption system to allow the gas in the reaction chamber to automatically flow to the back of the wafer, the solution of the present application greatly improves the working efficiency.

The structure of the vacuum adsorption system according to some embodiments of the present application is further described below.

Referring to FIG. 13 , in the vacuum adsorption system, a throttle valve TV is arranged on the first pipeline A to control the suction of the gas in the reaction chamber 100 by the vacuum pump 300 . In some embodiments, the air pressure Pc in the reaction chamber 100 can be measured by an air pressure measuring device 102 (such as a barometer or a vacuum gauge). The throttle valve TV can be adjusted according to the air pressure Pc in the reaction chamber 100 to control the gas flow in the first pipeline A, thereby controlling the air pressure Pc in the reaction chamber 100 to reach a desired level.

As shown in Figure 13, a first valve CHCV-1 is arranged on the second pipeline B close to the vent 201, and the third pipeline C is connected to the downstream of the first valve CHCV-1 on the second pipeline B ( That is, the side closer to the vacuum pump 300). A second valve CHCV-2 is arranged on the third pipeline C. In one embodiment, an air pressure controller 401 is disposed on the third pipeline C for adjusting the flow rate of the gas supplied to the vacuum adsorption system. As shown in the figure, the air pressure controller 401 may include a mass flow controller MFM, an adjustable flow valve 402 and an air pressure measuring device 403 (such as a barometer or a vacuum gauge). Those skilled in the art should understand that the air pressure controller 401 is not limited to the structure shown in the figure, and existing air pressure controllers or devices with similar functions can be used as the air pressure controller 401 .

Further referring to FIG. 13, the second pipeline B is bifurcated into the first manifold B1 and the second manifold B2 downstream of the first valve CHCV-1; the other end of the first manifold B1 is connected to the reaction chamber On the first pipeline A between the suction port 101 of 100 and the throttle valve TV, the third valve CHCV-3 is placed 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 line B2 can be connected to the first line A between the vacuum pump 300 and the throttle valve TV. The fourth valve CHCV-4 is disposed on the second manifold B2. In one embodiment, an air pressure measurement device 500 (such as a barometer or a vacuum gauge) can also be installed on the second manifold B2 to measure the air pressure Pb in the second manifold B2, which can reflect the adsorption inside the heater. Air pressure in the pipeline.

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 required, so that Realize the on-off control of the corresponding pipeline. The use of electromagnetic pneumatic valves can achieve more precise control. In other embodiments, other types of valves may also be used.

The present application also provides a method for absorbing wafers by using the above-mentioned vacuum adsorption system. In short, in this method, during the process of absorbing and/or releasing the wafer, the gas from the gas source 400 can be supplied to the adsorption line inside the heater using the second line B and the third line C , to adjust the pressure difference between the back and front of the wafer.

According to some embodiments of the present application, during the process of absorbing the wafer, the second pipeline B and the third pipeline C can be used to supply the gas from the gas source 400 into the adsorption pipeline inside the heater, so that the wafer To maintain the required pressure difference between the backside of the wafer and its front side, for example, keep the pressure on the backside of the wafer 30-150Torr less than the pressure on the front side. In the process of releasing the wafer, the second pipeline B and the third pipeline C can be used to supply the gas from the gas source 400 into the adsorption pipeline inside the heater, so that the pressure on the back side of the wafer can be increased to greater than or Equal to the pressure on its front, e.g. raise the pressure on the back of the wafer to be 5-10 Torr greater than the pressure on its front. At this time, the suction force is completely eliminated and there is a certain pushing force on the back side of the wafer, so the wafer can be easily moved to the next station.

In general, according to some embodiments of the present application, the method for absorbing a wafer by using the above-mentioned vacuum adsorption system mainly includes the following steps:

(a) Wafer placement: when the vacuum adsorption system is in the closed state (that is, both the second pipeline B and the third pipeline C are in the closed state), the vacuum adsorption method for placing the wafer in the reaction chamber 100 on the bearing surface of the heater 200;

(b) Adsorption wafer: start the vacuum adsorption system, continuously suck the gas in the adsorption pipeline inside the vacuum adsorption heater 200 through the second pipeline B, so that the pressure on the back of the wafer is kept lower than the pressure on its front, Thereby, the wafer is adsorbed on the carrying surface of the vacuum adsorption heater 200; and

(c) Release the wafer: after the wafer has been processed, stop the suction of the gas in the adsorption pipeline inside the vacuum adsorption heater 200, and utilize the second pipeline B and the third pipeline C to release the gas from the gas source The gas at 400 is supplied into the adsorption pipeline inside the vacuum adsorption heater 200, so that the pressure on the backside of the wafer is raised to be equal to or greater than the pressure on the front side thereof to release the wafer.

In some embodiments, the above method may also include at least one of the following steps:

(a1) Before step (a), heating the bearing surface of the vacuum adsorption heater 200 (for example, heating to 450-500° C.), and pumping the reaction chamber 100 to a vacuum state by the vacuum pump 300; and

(a2) After step (a) and before step (b), inject gas into the reaction chamber 100 (can pass through other pipelines, not shown in the figure), so that the air pressure Pc in the reaction chamber 100 rises (according to If necessary, Pc can be increased to 200-600 Torr, and the air pressure above the throttle valve TV can reach 200 Torr).

In one embodiment of the present application, in step (a2), when the pressure Pc in the reaction chamber 100 rises above a threshold value (for example, 100 Torr), step (b) starts. In step (b), while using the vacuum pump 300 to continuously suck the gas in the adsorption pipeline inside the vacuum adsorption heater 200 through the second pipeline B, the second pipeline B and the third pipeline C supplies the gas from the gas source 400 into the adsorption line inside the vacuum adsorption heater 200, so that the pressure on the back side of the wafer is kept 30-150 Torr lower than the pressure on the front side. The specific pressure difference can be adjusted according to the needs of wafer adsorption.

As mentioned above, the throttle valve TV is installed on the first pipeline A; the first valve CHCV-1 is installed near the vent 201 on the second pipeline B; the third pipeline C is connected to the second pipeline Downstream of the first valve CHCV-1 on B, and the second valve CHCV-2 is placed on the third pipeline C; the second pipeline B is branched into the first manifold pipeline downstream of the first valve CHCV-1 B1 and the second manifold B2; the other end of the first manifold B1 is connected to the first pipeline A between the suction port 101 of the reaction chamber 100 and the throttle valve TV, and the third valve CHCV-3 is arranged 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, as shown in Figure 13 ), the fourth valve CHCV-4 is placed on the second manifold B2. The specific working process of these valves and their corresponding pipelines is as follows:

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 opened, so that only the first pipeline A is in an open state, whereby the vacuum pump 300 pumps the reaction chamber 100 to a vacuum state. These valves remain in this state during step (a) (ie, placing the wafer) and step (a2).

In step (b) (ie, adsorption of the wafer), the first valve CHCV-1, the second valve CHCV-2, and the fourth valve CHCV-4 are all opened, and the third valve CHCV-3 is closed. The vacuum pump 300 continues to pump the gas in the reaction chamber 100 through the first pipeline A, so as to maintain the pressure Pc in the reaction chamber 100 at a desired level (for example, 200 Torr). At this time, the second pipeline B, the second manifold B2 and the third pipeline C are in the open state, so that the vacuum pump 300 sucks the gas in the adsorption pipeline inside the vacuum adsorption heater 200 (that is, the gas of the wafer gas on the back). At the same time, the gas source 400 can feed gas into the vacuum adsorption system, and the amount of gas fed (ie, the flow rate of the gas in the third pipeline C) can be controlled by adjusting the air pressure controller 401 . The gas sucked by the vacuum pump 300 from the adsorption pipeline of the vacuum adsorption heater 200 through the second pipeline B and the second manifold pipeline B2, and the gas source 400 passes through the third pipeline C to the adsorption pipeline. Under the combined effect of the injected gas, the pressure on the back of the wafer is kept 30-150Torr lower than the pressure on the front. The specific pressure difference can be set as required.

In step (c) (ie, releasing the wafer), the first valve CHCV-1, the second valve CHCV-2, and the third valve CHCV-3 are all opened, and the fourth valve CHCV-4 is closed. The vacuum pump 300 continues to pump the gas in the reaction chamber 100 through the first pipeline A, so as to maintain the pressure Pc in the reaction chamber 100 at a desired level (for example, 200 Torr). At this time, on the one hand, the gas in the reaction chamber 100 can enter the adsorption pipeline inside the vacuum adsorption heater through the first pipeline A, the first manifold pipeline B1 and the second pipeline B, so as to reach the wafer On the other hand, the external gas (such as nitrogen) from the gas source 400 enters the adsorption pipeline inside the vacuum adsorption heater through the third pipeline C and the second pipeline B, thereby reaching the back surface of the wafer. . Due to the effects of these two gases, the pressure on the back of the wafer rises rapidly, and the pressure difference between it and the front decreases rapidly, and the flow rate of the gas on the third pipeline C can even be adjusted by adjusting the air pressure controller 401. And the pressure on the back of the wafer is increased to be equal to or greater than the pressure on the front, for example, the pressure on the back of the wafer is increased to 5-10Torr greater than the pressure on the front, so as to quickly eliminate the adsorption force, and then quickly release the wafer. round purpose. Obviously, this mode of operation greatly improves the working efficiency.

The technical content and technical features of the present application have been described by the above-mentioned relevant embodiments, but the above-mentioned embodiments are only examples for implementing the present application. Those skilled in the art may still make various substitutions and modifications based on the teaching and disclosure of the present application without departing from the spirit of the present application. Therefore, the disclosed embodiments of this application do not limit the scope of this application. On the contrary, modifications and equivalent arrangements that do not depart from the spirit and scope of the application are included in the scope of the application.

Claims

A vacuum adsorption system, which is used to absorb and release wafers located on the carrying surface of a vacuum adsorption heater (200) in a reaction chamber (100), the reaction chamber (100) has a suction port ( 101), the vacuum adsorption heater (200) has a vent (201), and the system includes:

A first pipeline (A), which is used to fluidly couple the pumping port (101) of the reaction chamber (100) with a vacuum pump (300);

a second pipeline (B) for fluidly coupling the vent (201) of the vacuum adsorption heater (200) with the vacuum pump (300); and

A third line (C) connected to said second line (B) for supplying gas from a gas source (400) to said vacuum adsorption system.
The vacuum adsorption system according to claim 1, wherein a first valve (CHCV-1) is arranged on the second pipeline (B) near the vent (201), and the third pipeline (C ) is connected downstream of said first valve (CHCV-1) on said second pipeline (B).
The vacuum adsorption system according to claim 2, wherein a second valve (CHCV-2) is arranged on the third pipeline (C).
The vacuum adsorption system according to claim 3, wherein an air pressure controller (401) is further arranged on the third pipeline (C), which is used to adjust the flow rate of the gas supplied to the vacuum adsorption system.
The vacuum adsorption system according to claim 4, wherein the air pressure controller (401) comprises a mass flow controller (MFM), an adjustable flow valve (402) and an air pressure measuring device (403).
The vacuum adsorption system according to claim 3, wherein:

A throttling valve (TV) is arranged on the first pipeline (A);

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), the third valve (CHCV-3) is placed on the first manifold (B1);

The other end of the second manifold (B2) is connected to the vacuum pump (300), and a fourth valve (CHCV-4) is arranged on the second manifold (B2).
The vacuum adsorption system according to claim 6, wherein an air pressure measuring device (500) is further arranged on the second manifold line (B2).
The vacuum adsorption system according to claim 6, wherein said first valve (CHCV-1), said second valve (CHCV-2), said third valve (CHCV-3) and said fourth valve (CHCV-4) are electromagnetic pneumatic valves.
A method for absorbing a wafer by using the vacuum adsorption system according to claim 1, comprising: using the second pipeline (B) and the second pipeline during the process of absorbing and/or releasing the wafer Three pipelines (C) supply the gas from the gas source (400) to the adsorption pipeline inside the vacuum adsorption heater (200) to adjust the pressure difference between the back and front of the wafer, Wherein the adsorption pipeline is in fluid communication with the vent (201).
The method according to claim 9, wherein: in the process of absorbing the wafer, the gas source (400) The gas is supplied to the adsorption pipeline, so that the pressure on the back side of the wafer is kept 30-150 Torr lower than the pressure on the front side.
The method according to claim 9, wherein: in the process of releasing the wafer, the gas source (400) The gas is supplied to the adsorption pipeline, so that the pressure on the back side of the wafer is increased to be greater than or equal to the pressure on the front side thereof.
The method according to claim 9, wherein: in the process of releasing the wafer, the gas source (400) The gas is supplied to the adsorption pipeline, so that the pressure on the back side of the wafer is increased to 5-10 Torr higher than the pressure on the front side.
A method utilizing vacuum adsorption system adsorption wafer according to claim 1, it comprises the following steps:

(a) placing the wafer: when the vacuum adsorption system is in a closed state, place the wafer on the carrying surface of the vacuum adsorption heater (200) in the reaction chamber (100) superior;

(b) Adsorb the wafer: start the vacuum adsorption system, continuously suck the gas in the adsorption pipeline inside the vacuum adsorption heater (200) through the second pipeline (B), so that The pressure on the back side of the wafer is kept lower than the pressure on the front side, thereby the wafer is adsorbed on the carrying surface of the vacuum adsorption heater (200), wherein the adsorption pipeline is connected to the vent ( 201) fluid communication; and

(c) Release the wafer: after the wafer is processed, stop sucking the gas in the adsorption pipeline inside the vacuum adsorption heater (200), and use the second tube to Road (B) and the third pipeline (C) supply the gas from the gas source (400) to the adsorption pipeline so that the pressure on the back side of the wafer is raised to be equal to or greater than its positive pressure to release the wafer.
The method of claim 13, further comprising at least one of the following steps:

(a1) before step (a), heating the bearing surface of the vacuum adsorption heater (200), and pumping the reaction chamber (100) to a vacuum state by the vacuum pump (300); and

(a2) After the step (a) and before the step (b), inject gas into the reaction chamber (100) to increase the air pressure (Pc) in the reaction chamber (100).
The method of claim 14, wherein:

In step (a2), when the gas pressure (Pc) in the reaction chamber (100) rises above a threshold value, step (b) starts.
The method of claim 15, wherein the threshold is 100 Torr.
The method of claim 13, wherein:

In step (b), when using the vacuum pump (300) to continuously suck the gas in the adsorption pipeline in the vacuum adsorption heater (200) through the second pipeline (B), At the same time, the gas from the gas source (400) is supplied into the adsorption pipeline through the second pipeline (B) and the third pipeline (C), so that the backside of the wafer The pressure maintained is 30-150Torr less than the pressure on its face.
The method of claim 13, wherein:

A throttling valve (TV) is arranged on the first pipeline (A);

A first valve (CHCV-1) arranged on the second pipeline (B) close to the vent (201);

The third pipeline (C) is connected to the downstream of the first valve (CHCV-1) on the second pipeline (B), and a second Valve (CHCV-2);

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) a third valve (CHCV-3) is placed on said first manifold line (B1); and

The other end of the second manifold (B2) is connected to the vacuum pump (300), and a fourth valve (CHCV-4) is arranged on the second manifold (B2).
The method of claim 18, 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 closed, the throttle valve (TV) is opened.
The method of claim 18, wherein:

During the execution of 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) Close.
The method according to claim 20, 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 remains smaller than the pressure on the front side thereof 30-150 Torr.
The method of claim 18, wherein:

During the execution of 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) Close.
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 raised to be equal to or greater than its positive pressure.
The method according to claim 23, 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 raised to be higher than that on the front side The pressure is 5-10Torr.