Electrostatic chuck and semiconductor processing device

Abstract

The present invention provides an electrostatic chuck and a semiconductor processing apparatus, in which a gas passage structure includes an annular gas passage, a group of main gas passages and a group of sub gas passages, the annular gas passage is located near the edge of the upper surface of the chuck body and is used to define a heat exchange area therein, the group of main gas passages is circling around a central intake hole, the group of sub gas passages is circling around the group of main gas passages, the group of main gas passages is respectively connected to the central intake hole and the group of sub gas passages, and is arranged to improve the speed of sending back blow gas flowing out from the central intake hole to the group of sub gas passages, and the group of sub gas passages is respectively connected to the group of main gas passages and the annular gas passage, and is arranged to uniformly distribute the back blow gas to various positions in the heat exchange area.

Description

[Technical field]

[0001] The present invention relates to the field of semiconductor manufacturing, and more particularly to electrostatic chucks and semiconductor processing equipment. [Background technology]

[0002] Electrostatic chuck (ESC) mounts the wafer by electrostatic attraction to avoid the wafer moving or shifting during the process. In the process, it is also necessary to inject a certain pressure of back blow gas into the gap between the electrostatic chuck and the wafer to improve the heat transfer ability of the electrostatic chuck to the wafer and avoid vacuum insulation, which can improve the ability of the electrostatic chuck to control the wafer temperature, and the electrostatic chuck can also supply RF bias to the wafer.

[0003] The electrostatic chuck is usually placed in a vacuum chamber. For example, in a physical vapor deposition (PVD) device, when a wafer is transferred into the vacuum chamber of the PVD device and placed on the electrostatic chuck, the vacuum chamber is in a background vacuum state (the background vacuum level is usually 10 -8 Torr or 10 -9 At this time, the wafer and electrostatic chuck are in a vacuum insulation state, and the electrostatic chuck cannot control the temperature of the wafer, so it is necessary to inject back-blow gas into the gap between them to maintain a constant gas pressure (for example, 1 to 20 Torr). The back-blow gas transfers heat between the electrostatic chuck and the wafer, thereby realizing the temperature control capability of the electrostatic chuck.

[0004] Electrostatic chucks are divided into two types: Coulomb type and Johnsen-Rahbek type (abbreviated as JR type). The operating principle of the Coulomb type electrostatic chuck is to attract the wafer by utilizing the electrostatic attraction generated between the electrode and the wafer, while the operating principle of the JR type electrostatic chuck is to attract the wafer by utilizing the electrostatic attraction generated between the upper surface of the electrostatic chuck and the wafer. In order to improve the heat transfer efficiency, a gas passage is usually provided on the upper surface of the electrostatic chuck, which contributes to the back-blow gas diffusing to various positions on the wafer through the gas passage. However, in the Coulomb type electrostatic chuck, the electrode is close to the wafer, so the thickness of the dielectric layer above the electrode is thin, and the gas passage cannot be provided. In contrast, in the JR type electrostatic chuck, the electrode is far from the wafer, and the dielectric layer above the electrode is thick, so that the gas passage can be manufactured.

[0005] However, in the case of the JR type electrostatic chuck, the conventional gas passage structure requires the back blow gas to be injected for a long time (100 s or more) so that the stability and uniformity of the back blow gas pressure can meet the process requirements and the PVD process can be started, but the time of the PVD process is generally only in the range of 20 to 100 s, resulting in low productivity of the device and not applicable to industrial production. Summary of the Invention [Problem to be solved by the invention]

[0006] In order to solve at least one of the technical problems of the prior art, the present invention aims to provide an electrostatic chuck and a semiconductor processing apparatus that can effectively shorten the gas injection time of the back blow gas while ensuring that the back blow gas pressure meets the requirements of stability and uniformity, thereby improving the productivity of the apparatus. [Means for solving the problem]

[0007] In order to achieve the object of the present invention, a semiconductor processing apparatus is provided, comprising a chuck body, an upper surface of the chuck body is provided with a bump structure, a central air intake hole and a gas passage structure, the bump structure is located in a non-gas passage area of ​​the upper surface of the chuck body and is used for placing a wafer, the bump structure has a placement surface for placing a wafer, and there is a predetermined gap between the placement surface and the upper surface of the chuck body, the gas passage structure includes an annular gas passage, a group of main gas passages and a group of sub gas passages, the annular gas passage is located at the edge of the upper surface of the chuck body and is used to define a heat exchange area therein, the group of main gas passages and the group of sub gas passages are both distributed within the heat exchange area, the group of main gas passages are circumferential around the central intake hole, and the group of sub gas passages are circumferential around the group of main gas passages, the main gas passage group is connected to the central intake hole and the sub gas passage group, respectively, and is provided so as to increase the speed at which back blow gas flowing out from the central intake hole is sent to the sub gas passage group, The sub gas passages are connected to the main gas passages and the annular gas passage, respectively, to provide an electrostatic chuck that can uniformly distribute the back blow gas to various positions in the heat exchange region.

[0008] Optionally, a ratio of an area of ​​the main gas passage group as orthogonal projections on the upper surface of the chuck body to an area of ​​a specified region on the upper surface of the chuck body is 50% or less, and the area of ​​the specified region is an area of ​​a circle having a center at the center of the upper surface and a specified diameter.

[0009] Optionally, the specified diameter is 50 mm or less.

[0010] Optionally, the main gas passage group includes a plurality of main gas passages evenly distributed in a circumferential direction of the central air intake hole, each of the main gas passages is provided in a radial direction of the central air intake hole, and each of the main gas passages has an intake end connected to the central air intake hole, and each of the main gas passages has an exhaust end connected to the sub-gas passage group.

[0011] Optionally, the width of the main gas passage is between 0.5mm and 3mm, the depth of the main gas passage is between 0.1mm and 0.4mm, and the number of the main gas passages is between 9 and 20.

[0012] Selectively, the sub-gas passage group includes one stage of sub-gas passage groups, the sub-gas passage group includes a plurality of sub-gas passages, each of the main gas passages has an exhaust end communicating with an intake end of at least one of the sub-gas passages, and the plurality of sub-gas passages communicating with the same main gas passage extend in different directions away from the central intake hole from the exhaust end of the main gas passage, or The sub-gas passage group includes a plurality of stages of sub-gas passage groups which are arranged in sequence in a direction away from the central intake hole, and each of the sub-gas passage groups of each stage includes a plurality of sub-gas passages, an exhaust end of each of the main gas passages is connected to an intake end of at least one of the sub-gas passages in an adjacent stage of the sub-gas passage group, the plurality of sub-gas passages connected to the same main gas passage extend from the exhaust end of the main gas passage in different directions away from the central intake hole, an exhaust end of each sub-gas passage of an upstream stage is connected to an intake end of at least one sub-gas passage of an adjacent downstream stage, and the plurality of sub-gas passages of a downstream stage which are connected to the same sub-gas passage of an upstream stage extend from the exhaust ends of the sub-gas passages of the upstream stage in different directions away from the central intake hole.

[0013] Optionally, the width of the sub gas passage is between 0.5 mm and 3 mm, the depth of the sub gas passage is between 0.1 mm and 0.4 mm, and the number of the sub gas passages is between 9 and 100.

[0014] Selectively, the sub-gas passage group includes two stages of the sub-gas passage group, which are a first stage gas passage group and a second stage gas passage group, the first stage gas passage group includes a plurality of first sub-gas passages, an exhaust end of each of the main gas passages is connected to the intake ends of three of the first sub-gas passages, among the three first sub-gas passages connected to the same main gas passage, the middle first sub-gas passage is coaxial with the main gas passage, the two first sub-gas passages on both sides are distributed symmetrically with respect to the middle first sub-gas passage and connected to different main gas passages, and exhaust ends of any two adjacent first sub-gas passages are joined to form a first common exhaust end, The second stage gas passage group includes a plurality of second sub-gas passages, and among the three first sub-gas passages communicating with the same main gas passage, an exhaust end of the middle first sub-gas passage communicates with the intake ends of two of the second sub-gas passages, and each of the first common exhaust ends communicates with the intake ends of the two second sub-gas passages, and any two adjacent second sub-gas passages communicating with the exhaust ends of the first sub-gas passages and the exhaust ends of the second sub-gas passages communicating with the first common exhaust ends join together to form a second common exhaust end, and all of the second common exhaust ends communicate with the annular gas passage.

[0015] Optionally, the sub-gas passage group further includes a plurality of transition gas passages, an intake end of each of the transition gas passages communicating with each of the second common exhaust ends in a one-to-one correspondence, and an exhaust end of each of the transition gas passages communicating with the annular gas passage.

[0016] Optionally, the annular gas passage has an annular centerline diameter between 270mm and 290mm, a radial width of the annular gas passage between 0.5mm and 3mm, and a depth of the annular gas passage between 0.1mm and 0.4mm.

[0017] Optionally, the bump structure includes a plurality of bumps evenly distributed within the non-gas passage region, and a ratio of a total area of ​​the orthogonal projections of the plurality of bumps on the upper surface of the chuck body to an area of ​​the upper surface of the chuck body is greater than or equal to 2% and less than or equal to 10%.

[0018] Optionally, the predetermined spacing is between 2 μm and 10 μm.

[0019] As another technical solution, the present invention further provides a semiconductor processing apparatus including a process chamber and an electrostatic chuck provided in the process chamber, the electrostatic chuck using the electrostatic chuck according to the present invention as the electrostatic chuck.

[0020] The present invention has the following beneficial effects:

[0021] According to the electrostatic chuck of the present invention, the gas passage structure includes an annular gas passage, a group of main gas passages and a group of sub gas passages, the annular gas passage is located near the edge of the upper surface of the chuck body and is used to define a heat exchange area inside thereof, thereby ensuring that the gas pressure in the area is not affected by the chamber pressure, ensuring the stability of the gas pressure, and enabling the normal heat exchange of the back blow gas. The group of main gas passages and the group of sub gas passages are both distributed in the heat exchange area, the group of main gas passages are arranged around the central intake hole and communicate with the central intake hole and the group of sub gas passages respectively, so as to improve the speed of sending the back blow gas flowing out from the central intake hole to the group of sub gas passages, so as to ensure that the back blow gas can be quickly diffused from the central intake hole to the surroundings. The group of sub gas passages are arranged around the group of main gas passages and communicate with the group of main gas passages and the annular gas passage respectively, so as to evenly distribute the back blow gas to various positions in the heat exchange area. The main gas passage group plays a major role in ensuring that the back-blow gas pressure quickly meets the stability requirements, and the sub gas passage group plays a major role in ensuring that the back-blow gas quickly meets the uniformity requirements. Therefore, by using the main gas passage group and the sub gas passage group in combination, the back-blow gas pressure can be made to meet the stability and uniformity requirements, and the gas injection time of the back-blow gas can be effectively shortened, thereby improving the productivity of the device.

[0022] According to the semiconductor processing equipment of the present invention, by using the electrostatic chuck of the present invention, the back blow gas pressure can be ensured to meet the requirements of stability and uniformity, and the gas injection time of the back blow gas can be effectively shortened, thereby improving the productivity of the equipment. [Brief description of the drawings]

[0023] [Figure 1] 1 is a schematic cross-sectional side view of an electrostatic chuck according to a first embodiment of the present invention. [Diagram 2] 1 is a top view of a gas passage structure of an electrostatic chuck according to a first embodiment of the present invention. FIG. [Diagram 3] FIG. 4 is another top view of the gas passage structure of the electrostatic chuck according to the first embodiment of the present invention. [Figure 4] FIG. 11 is a top view of a gas passage structure of an electrostatic chuck according to a second embodiment of the present invention. [Diagram 5] FIG. 11 is an overall top view of an electrostatic chuck according to a third embodiment of the present invention. [Figure 6] FIG. 6 is a partial top view of the electrostatic chuck in FIG. 5. [Figure 7] FIG. 10 is a comparison of average gas pressure-time curves for an electrostatic chuck used in a third embodiment of the present invention and a prior art electrostatic chuck. [Figure 8] FIG. 10 is a comparison diagram of gas pressure-wafer position curves of an electrostatic chuck used in the third embodiment of the present invention and an electrostatic chuck of the prior art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In order to make those skilled in the art better understand the technical solution of the present invention, the electrostatic chuck and semiconductor processing apparatus of the present invention will be described in detail below with reference to the accompanying drawings.

[0025] First Example As shown in Fig. 1, this embodiment provides an electrostatic chuck 1, which includes a chuck body 11, in which an electrode 12 is provided, and the electrode 12 is usually electrically connected to a DC power source for supplying power for attracting a wafer. Usually, a portion of the chuck body 11 located above the electrode 12 is a dielectric layer, and a portion of the chuck body 11 located below the electrode 12 is a base. Both the dielectric layer and the base are made of a ceramic material, and the electrode 12 can be embedded in the ceramic material by sintering.

[0026] The electrostatic chuck 1 according to the present embodiment is a Johnsen-Rahbek effect (JR type) electrostatic chuck, and its operating principle is to adsorb the wafer 2 by utilizing the electrostatic attractive force generated between the upper surface 111 of the chuck body 11 and the wafer 2. Based on this, in this embodiment, a bump structure, a central air intake hole, and a gas passage structure are provided on the upper surface 111 of the chuck body 11, the bump structure includes a plurality of bumps 13 evenly distributed in the non-gas passage area (area excluding the central air intake hole and the gas passage structure), a mounting surface composed of the plurality of bumps 13 is used to mount the wafer 2, and there is a predetermined interval (i.e., the height of the bumps 13) between the mounting surface and the upper surface 111 of the chuck body 11, and the predetermined interval is set so as to be able to generate a sufficient electrostatic attractive force between the upper surface 111 of the chuck body 11 and the wafer 2, thereby ensuring that the wafer 2 is prevented from moving or shifting during the process.

[0027] The following formula is Coulomb's law.

[0028]

number

[0029] In the formula, F is the electrostatic attractive force, K is the Coulomb's constant, Q is the amount of charge on the upper surface 111, q is the amount of charge on the lower surface of the wafer 2, and r is the distance between the lower surface of the wafer 2 and the upper surface 111 of the chuck body 11 (in the case of a JR type electrostatic chuck). As can be seen from Coulomb's law, the electrostatic attractive force F is inversely proportional to the square of the distance r, so the magnitude of the electrostatic attractive force F mainly depends on the distance r, and the smaller the distance r, the greater the electrostatic attractive force F. Also, since the electrostatic attractive force F is directly proportional to the charge amount Q of the upper surface 111, the larger the area of ​​the region of the upper surface 111 excluding the bump structure and gas passage structure, the greater the electrostatic attractive force F.

[0030] Based on the above principle, the predetermined distance between the mounting surface formed of the plurality of bumps 13 and the upper surface 111 of the chuck body 11 is selectably 2 μm or more and 10 μm or less. By setting the predetermined distance within this range, it is possible to avoid not only a situation in which the predetermined distance is too large, resulting in insufficient electrostatic attractive force F and causing movement or displacement of the wafer 2 during processing, but also a situation in which the predetermined distance is smaller than the molecular mean free path of the back blow gas injected between the wafer 2 and the upper surface 111 during processing, resulting in deterioration of the thermal conductivity of the back blow gas and impairing the temperature control ability of the electrostatic chuck.

[0031] Also, the ratio of the total area of ​​the orthogonal projections of the plurality of bumps 13 on the upper surface 111 of the chuck body 11 to the area of ​​the upper surface 111 can be selectably set to 2% or more and 10% or less. By setting the ratio within the range, it is possible to avoid a situation in which the area of ​​the upper surface 111 is insufficient due to a ratio that is too large, which in turn causes a shortage of the amount of charge Q on the upper surface 111 and ultimately causes a shortage of the electrostatic attractive force F, as well as to avoid a situation in which the ratio is too small and therefore the wafer 2 cannot be supported uniformly and stably.

[0032] In some selectable embodiments, the bumps 13 may be evenly arranged on multiple circles with different radii in the non-gas passage area, with the center of the upper surface 111 as the center, as in the arrangement of the bumps 13 shown in Fig. 5. Alternatively, the bumps 13 may be arranged in an array in the non-gas passage area, and the array may be, for example, a rectangular array or an array of any other shape. The present invention does not particularly limit the number or arrangement of the bumps 13.

[0033] In some alternative embodiments, the bumps 13 are fabricated from TAC (hydrogen-free diamond-like carbon) material by a filtered cathodic vacuum arc (FCVA) method, which has excellent wear resistance and can withstand high temperatures, thereby extending the life of the electrostatic chuck.

[0034] In some optional embodiments, the distance between the electrode 11 and the upper surface 111 of the chuck body 11 is 0.5 mm or more and 2 mm or less, and by setting the distance within this range, a good electrostatic attractive force F can be obtained.

[0035] As shown in FIG. 2, the central intake hole 112 is located at the center of the upper surface 111 of the chuck body 11, and by injecting back-blow gas between the upper surface 111 and the wafer 2, heat exchange between the two is achieved, thereby achieving temperature control of the electrostatic chuck.

[0036] As shown in FIG. 2, the gas passage structure includes an annular gas passage 31, a group of main gas passages and a group of sub gas passages. The annular gas passage 31 is located near the edge of the upper surface 111 of the chuck body 11 and is used to define the above-mentioned heat exchange area (including the inner ring area 111a and the outer ring area 111b) inside the annular gas passage 31. Since the edge area 111c of the upper surface 111 of the chuck body 11 communicates with the inside of the chamber, the gas pressure in the area drops suddenly, and as a result, the heat exchange of the back blow gas in the edge area 111c becomes impossible. In this case, the annular gas passage 31 ensures that the gas pressure in the heat exchange area (including the inner ring area 111a and the outer ring area 111b) inside the annular gas passage 31 is not affected by the chamber pressure, and the stability of the gas pressure can be ensured, enabling the normal heat exchange of the back blow gas.

[0037] In some alternative embodiments, the diameter of the annular center line of the annular gas passage 31 is 270mm to 290mm, preferably 280mm, the radial width of the annular gas passage 31 is 0.5mm to 3mm, preferably 2mm, and the depth of the annular gas passage 31 is 0.1mm to 0.4mm, preferably 0.2mm. The setting ranges of the diameter, radial width and depth of the annular center line of the annular gas passage 31 can not only ensure that the area of ​​the heat exchange area is as large as possible, but also ensure that the gas pressure in the heat exchange area inside the annular gas passage 31 is not affected by the chamber pressure, and ensure the stability of the gas pressure, enabling the normal heat exchange of the back blow gas.

[0038] The main gas passage group and the sub gas passage group are both distributed in the above-mentioned heat exchange area, the main gas passage group is arranged around the central intake hole 112, for example, located in the inner ring area 111a in FIG. 2, and the sub gas passage group is arranged around the main gas passage group, for example, located in the outer ring area 111b in FIG. 2. The main gas passage group is respectively connected to the central intake hole 112 and the sub gas passage group, and is arranged to improve the speed at which the back blow gas flowing out from the central intake hole 112 is sent to the sub gas passage group, thereby ensuring that the back blow gas can be rapidly diffused from the central intake hole 112 to the surroundings, that is, to improve the diffusion speed of the back blow gas, and the main gas passage group plays a major role in quickly meeting the stability requirements of the back blow gas pressure.

[0039] The main gas passage group is located in the inner ring region 111a close to the central intake hole 112, but the gas pressure in the central intake hole 112 is higher than in other regions. If the area of ​​the main gas passage group orthogonally projected on the upper surface 111 of the chuck body 11 is too large, the gas pressure in the inner ring region 111a is likely to become high, and the "bulge" phenomenon of the wafer occurs in the region. To solve this problem, the ratio of the area of ​​the main gas passage group orthogonally projected on the upper surface 111 of the chuck body 11 to the area R of the designated region is 50% or less, and the area R of the designated region is the area of ​​a circle whose center is the center of the upper surface 111 and whose diameter is a designated diameter, that is, the region within the outer periphery of the inner ring region 111a. Optionally, the designated diameter is, for example, 50 mm or less, for example, 50 mm. Of course, in order to ensure that the back-blow gas can be quickly diffused from the central intake hole 112 to the surroundings and the back-blow gas pressure can quickly meet the stability requirements, it is not preferable that the area of ​​the orthogonal projection of the main gas passage group on the upper surface 111 of the chuck body 11 is too small.

[0040] In some alternative embodiments, the main gas passage group includes a plurality of main gas passages 32 evenly distributed in the circumferential direction of the central intake hole 112, and each main gas passage 32 is arranged in the radial direction of the central intake hole 112, thereby shortening the path of the back-blow gas flowing to the outer ring region 111b, thereby ensuring that the back-blow gas can be quickly diffused from the central intake hole 112 to the surroundings. In addition, the intake ends of each main gas passage 32 are all connected to the central intake hole 112, and the exhaust ends of each main gas passage 32 are all connected to the sub-gas passage group. The back-blow gas flowing out from the central intake hole 112 simultaneously diffuses to the surroundings through each main gas passage 32 and flows into the sub-gas passage group.

[0041] In some selectable embodiments, the area of ​​the orthogonal projection of the main gas passages on the upper surface 111 of the chuck body 11 can be adjusted by setting parameters such as the number, width, and depth of the main gas passages 32, for example, the width of the main gas passages 32 is 0.5 mm to 3 mm, preferably 2 mm, the depth of the main gas passages 32 is 0.1 mm to 0.4 mm, preferably 0.2 mm, and the number of the main gas passages 32 is 9 to 20, preferably 10. For example, 15 main gas passages 32 are shown in FIG. By setting the number, width and depth of the main gas passages 32 within the above numerical ranges, it is possible to not only avoid the main gas passage group having an excessively large orthogonal projection area on the upper surface 111 of the chuck body 11, which would result in an increase in gas pressure in the inner ring region 111a and the occurrence of the wafer "bulging" phenomenon in that region, but also ensure that the orthogonal projection area on the upper surface 111 of the chuck body 11 is sufficiently large so that the back-blow gas can be quickly diffused from the central intake hole 112 to the surroundings, thereby realizing that the back-blow gas pressure quickly meets the stability requirements.

[0042] In addition, the main gas passage group is not limited to the structure used in the above embodiment, and any other structure may be used in actual use as long as the back blow gas pressure quickly meets the stability requirement.

[0043] The sub-gas passage group is connected to the main gas passage group and the annular gas passage 31, respectively, and is provided so as to distribute the back-blow gas uniformly to various positions in the heat exchange area (including the inner ring area 111a and the outer ring area 111b), that is, the sub-gas passage group can diffuse the back-blow gas quickly and uniformly. The sub-gas passage group plays a major role in making the back-blow gas quickly meet the requirements for uniformity, therefore, by using the main gas passage group and the sub-gas passage group in combination, the back-blow gas pressure can be ensured to meet the requirements for stability and uniformity, and the gas injection time of the back-blow gas can be effectively shortened, thereby improving the productivity of the device.

[0044] In addition, since the distance between the gas passage area in which the main gas passage groups and the sub gas passage groups are located and the wafer surface is large, and the distance between the non-gas passage area of ​​the upper surface 111 and the wafer surface is small, the main gas passage groups and the sub gas passage groups can act to guide the diffusion of the back blow gas. Furthermore, since both of them are connected to the non-gas passage area, the back blow gas flows sequentially along the main gas passage groups and the sub gas passage groups, and then further diffuses into the non-gas passage area, finally realizing that the back blow gas fills the entire heat exchange area, thereby realizing uniformity and stability of the gas pressure between the heat exchange area and the wafer surface.

[0045] In some alternative embodiments, the sub-gas passage group includes one stage of sub-gas passage group, as shown in FIG. 2, which is located in the outer ring region 111b and includes a plurality of sub-gas passages 33, the exhaust ends of each main gas passage 32 are connected to the intake ends of two sub-gas passages 33, and the two sub-gas passages 33 connected to the same main gas passage 32 extend in different directions away from the exhaust end of the main gas passage 32 and away from the central intake hole 112. For example, in FIG. 2, the two sub-gas passages 33 connected to the same main gas passage 32 extend in directions away from the central intake hole 112 and away from each other, and finally connect to the annular gas passage 31. By using each of the two sub-gas passages 33 as two branch passages of the main gas passage 32, the back-blow gas flowing out from the main gas passage 32 can be further diffused in different directions away from the exhaust end of the main gas passage 32 and away from the central intake hole 112, thereby enabling the back-blow gas to quickly meet the requirement of uniformity.

[0046] In actual use, the number of sub gas passages 33 communicating with the same main gas passage 32 may be one, in which case the different sub gas passages 33 can be connected to each other, and similarly, the back blow gas can quickly meet the requirement of uniformity. Alternatively, the number of sub gas passages 33 communicating with the same main gas passage 32 may be three or more, for example, as shown in Fig. 3, the number of sub gas passages 33 communicating with the same main gas passage 32 may be three, and the number can be freely set according to specific needs.

[0047] In some selectable embodiments, the width of the sub gas passage 33 is 0.5 mm or more and 3 mm or less, preferably 2 mm, the depth of the sub gas passage 33 is 0.1 mm or more and 0.4 mm or less, preferably 0.2 mm, and the number of the sub gas passages 33 is 9 to 100, preferably 20. By setting the width, depth and number of the sub gas passages 33 within the above numerical ranges, the back blow gas can effectively achieve the effect of quickly satisfying the requirement of uniformity.

[0048] Furthermore, the sub-gas passage 33 is not limited to a straight passage, but may be a curved passage, a bent passage, or any other passage of any shape, and the present invention is not particularly limited thereto.

[0049] Second Example 4, the electrostatic chuck according to this embodiment is similar to the first embodiment, except that the structure of the sub-gas passage group is different and a plurality of transition gas passages 34 are additionally provided. Only the differences between this embodiment and the first embodiment will be described in detail below.

[0050] Specifically, as shown in FIG. 4, in the upper surface 111 of the chuck body 11, an annular transition region 111d is further divided between the outer ring region 111b and the annular gas passage 31, and based on this, the sub-gas passage group includes one stage of sub-gas passage groups, which are located in the outer ring region 111b and include a plurality of sub-gas passages 33, the exhaust ends of each main gas passage 32 are all connected to the intake ends of two sub-gas passages 33, and the two sub-gas passages 33 connected to the same main gas passage 32 are arranged from the exhaust ends of the main gas passage 32 to the center. The sub-gas passages 33 extend in different directions away from the central air intake hole 112. For example, in FIG. 2, two sub-gas passages 33 connected to the same main gas passage 32 extend in directions away from the central air intake hole 112 and away from each other. The exhaust ends of any two adjacent sub-gas passages 33 connected to different main gas passages 32 merge to form a common exhaust end A, thereby realizing the mutual communication of these two sub-gas passages 33, and thereby further improving the efficiency with which the back-blow gas quickly meets the uniformity requirement.

[0051] The sub-gas passage group further includes a plurality of transition gas passages 34, which are located in the annular transition region 111d, with the intake ends of each transition gas passage 34 communicating with each common exhaust end A in a one-to-one correspondence, and the exhaust ends of each transition gas passage 34 communicating with the annular gas passage 31. The transition gas passages 34 can further connect the plurality of sub-gas passages 33, which are connected to each other, to the annular gas passage 31.

[0052] In actual use, the transition gas passage 34 may be omitted, i.e., the annular transition region 111d may not be provided, and the common exhaust end A may be extended directly to the position of the annular gas passage 31 so as to be connected to the annular gas passage 31.

[0053] Other structures and functions of the electrostatic chuck according to this embodiment are similar to those of the first embodiment, and therefore a repeated description will be omitted here.

[0054] Third Example 5 and 6, an electrostatic chuck according to this embodiment is similar to the first and second embodiments except that the sub-gas passage group has a different structure. Hereinafter, only the differences between this embodiment and the first and second embodiments will be described in detail.

[0055] 5 and 6, the sub-gas passage group includes two stages of sub-gas passage groups that are arranged in sequence in a direction away from the central intake hole 112, and both are located in the outer ring region. The two stages of sub-gas passage groups are a first stage gas passage group and a second stage gas passage group, and the first stage gas passage group includes a plurality of first sub-gas passages 33a and the second stage gas passage group includes a plurality of second sub-gas passages 33b.

[0056] The exhaust end of each main gas passage 32 is connected to the intake ends of the three first sub-gas passages 33a. Of the three first sub-gas passages connected to the same main gas passage 32, the middle first sub-gas passage 331 is coaxial with the main gas passage 32. The two first sub-gas passages 332 on both sides are symmetrically distributed with respect to the middle first sub-gas passage 331 and connected to different main gas passages 32. The exhaust ends of any two adjacent first sub-gas passages 331 join together to form a first common exhaust end A1. Of the three first sub-gas passages connected to the same main gas passage 32, the exhaust ends of the middle first sub-gas passage 331 are connected to the intake ends of the two second sub-gas passages 33a. The first common exhaust ends A1 are connected to the intake ends of the two second sub-gas passages 33b, and the exhaust ends of any two adjacent second sub-gas passages 33b that are connected to the exhaust ends of the first sub-gas passages 331 and the second sub-gas passages 33b that are connected to the first common exhaust end A1 join together to form the second common exhaust end A2, or the exhaust ends of any two adjacent second sub-gas passages 33b that are connected to different exhaust ends (including the exhaust end of the intermediate first sub-gas passage 331 and the first common exhaust end A1) join together to form the second common exhaust end A2, and each of the second common exhaust ends 33b is connected to the annular gas passage 31.

[0057] Optionally, the sub-gas passage group further includes a plurality of transition gas passages 34, the intake ends of each transition gas passage 34 being connected to the second common exhaust ends A2 in a one-to-one correspondence, and the exhaust ends of each transition gas passage 34 being connected to the annular gas passage 31.

[0058] The following experiment was carried out using the gas passage structure used in the electrostatic chuck shown in FIG. 5 as an example. The specific parameters are as follows: the widths of the main gas passage 32, the sub gas passage 33, the annular gas passage 31 and the transition gas passage 34 are all 2 mm; the number of main gas passages 32 is 15; the total number of the sub gas passages is 60; and the diameter of the annular center line of the annular gas passage 31 is 280 mm.

[0059] 7 is a comparison diagram of the average gas pressure-time curve of the electrostatic chuck used in the third embodiment of the present invention and the electrostatic chuck of the prior art. As shown in FIG. 7, when the average gas pressure reaches the B1 line, it is determined that the magnitude of the average gas pressure at this time meets the process requirements, and when the average gas pressure reaches the B2 line, it is determined that the stability of the average gas pressure at this time meets the process requirements, and at this time the PVD process can be started, and usually the value of B1 is 90% of the value of B2. Curve S1 is the average gas pressure-time curve of the electrostatic chuck of the prior art, and curve S2 is the average gas pressure-time curve of the electrostatic chuck used in the third embodiment of the present invention. By comparison, it can be seen that the time t2 (100 s or more) corresponding to the line B1 on curve S1 is longer than the time t1 (about 12 s) corresponding to the line B1 on curve S2. In other words, the electrostatic chuck used in the third embodiment of the present invention can meet the lines B1 and B2 more quickly than the prior art. From this, it is evident that the electrostatic chuck of this embodiment can effectively shorten the gas injection time of the back blow gas while ensuring that the back blow gas pressure meets the stability requirements.

[0060] 8 is a comparison diagram of the gas pressure-wafer position curve of the electrostatic chuck used in the third embodiment of the present invention and the conventional electrostatic chuck. As shown in FIG. 8, curve S1 is the gas pressure-wafer position curve of the conventional electrostatic chuck, and curve S2 is the gas pressure-wafer position curve of the electrostatic chuck used in the third embodiment of the present invention. By comparing, it can be seen that the magnitude of the gas pressure of curve S1 gradually decreases from the center position (150 mm) of the wafer to the edge position, the maximum gas pressure at the center position is 680 Pa, and the minimum gas pressure at the edge position is 340 Pa, and the uniformity of the gas pressure is poor. For curve S2, the difference between the gas pressure at the center position (150 mm) of the wafer and the gas pressure at the edge position is very small, both about 680 Pa. It is clear from this that the electrostatic chuck according to this embodiment can effectively improve the stability of the back blow gas pressure.

[0061] It should be noted that the above third embodiment is merely a preferred embodiment, and the present invention is not limited thereto. In actual use, the sub-gas passage group may include three or more stages of sub-gas passage groups arranged in sequence in a direction away from the central intake hole 112. In this case, the exhaust end of each main gas passage 32 is connected to the intake end of at least one sub-gas passage in an adjacent stage of the sub-gas passage group, the multiple sub-gas passages connected to the same main gas passage 32 extend from the exhaust end of the main gas passage 32 in different directions away from the central intake hole 112, the exhaust end of each sub-gas passage in the upstream stage is connected to the intake end of at least one sub-gas passage in the downstream stage adjacent thereto, and the multiple sub-gas passages in the downstream stage connected to the same sub-gas passage in the upstream stage extend from the exhaust ends of the sub-gas passages in the upstream stage in different directions away from the central intake hole 112.

[0062] Other structures and functions of the electrostatic chuck according to this embodiment are similar to those of the first and second embodiments described above, and therefore a repeated description will be omitted here.

[0063] As described above, the electrostatic chuck according to each of the above-mentioned embodiments of the present invention uses the main gas passage group and the sub gas passage group in combination, thereby ensuring that the back blow gas pressure meets the requirements for stability and uniformity, and effectively shortening the gas injection time of the back blow gas, thereby improving the productivity of the apparatus.

[0064] As another technical solution, an embodiment of the present invention further provides a semiconductor processing apparatus, including a process chamber and an electrostatic chuck provided in the process chamber, and the electrostatic chuck uses any of the electrostatic chucks according to the above embodiments of the present invention.

[0065] By using the electrostatic chuck according to the embodiment of the present invention, the semiconductor processing equipment according to the embodiment of the present invention can effectively shorten the gas injection time of the back blow gas while ensuring that the back blow gas pressure meets the requirements of stability and uniformity, thereby improving the productivity of the equipment.

[0066] It should be noted that the above embodiment is merely an illustrative embodiment adopted to explain the principles of the present invention, and the present invention is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. An electrostatic chuck applied to a semiconductor processing device, the electrostatic chuck including a chuck body, a bump structure, a central intake hole and a gas passage structure are provided on an upper surface of the chuck body, the bump structure is located in a non-gas passage area of ​​the upper surface of the chuck body, and has a support surface for supporting a wafer, the support surface being spaced apart from the upper surface of the chuck body by a predetermined distance; the gas passage structure includes an annular gas passage, a group of main gas passages and a group of sub gas passages, the annular gas passage is located at the edge of the upper surface of the chuck body and is used to define a heat exchange area therein, the group of main gas passages and the group of sub gas passages are both distributed within the heat exchange area, the group of main gas passages are circumferential around the central intake hole, and the group of sub gas passages are circumferential around the group of main gas passages, the main gas passage group is connected to the central intake hole and the sub gas passage group, respectively, and is provided so as to increase the speed at which back blow gas flowing out from the central intake hole is sent to the sub gas passage group, the sub-gas passage group is connected to the main gas passage group and the annular gas passage, respectively, and is provided so as to uniformly distribute the back blow gas to various positions in the heat exchange area.

2. 2. The electrostatic chuck of claim 1, wherein a ratio of an area of ​​the main gas passage group as orthogonal projections on the upper surface of the chuck body to an area of ​​a designated region on the upper surface of the chuck body is 50% or less, and the area of ​​the designated region is an area of ​​a circle having a center at the center of the upper surface and a specified diameter.

3. 3. The electrostatic chuck of claim 2, wherein the specified diameter is less than or equal to 50 mm.

4. 4. The electrostatic chuck according to claim 1, wherein the main gas passage group includes a plurality of main gas passages evenly distributed in a circumferential direction of the central intake hole, each of the main gas passages is provided in a radial direction of the central intake hole, and each of the main gas passages has an intake end connected to the central intake hole, and each of the main gas passages has an exhaust end connected to the sub-gas passage group.

5. 5. The electrostatic chuck according to claim 4, wherein the width of the main gas passage is 0.5 mm or more and 3 mm or less, the depth of the main gas passage is 0.1 mm or more and 0.4 mm or less, and the number of the main gas passages is 9 to 20.

6. the sub-gas passage group includes one stage of sub-gas passage group, the sub-gas passage group includes a plurality of sub-gas passages, an exhaust end of each of the main gas passages is connected to an intake end of at least one of the sub-gas passages, and the plurality of sub-gas passages connected to the same main gas passage extend in different directions away from the exhaust end of the main gas passage and away from the central intake hole, or 5. The electrostatic chuck according to claim 4, wherein the sub-gas passage group includes a plurality of sub-gas passage groups arranged in sequence in a direction away from the central intake hole, each of the sub-gas passage groups in each stage includes a plurality of sub-gas passages, an exhaust end of each of the main gas passages is connected to an intake end of at least one of the sub-gas passages in an adjacent stage of the sub-gas passage group, the plurality of sub-gas passages connected to the same main gas passage extend from the exhaust end of the main gas passage in different directions away from the central intake hole, an exhaust end of each sub-gas passage in an upstream stage is connected to an intake end of at least one sub-gas passage in an adjacent downstream stage, and the plurality of sub-gas passages in a downstream stage connected to the same sub-gas passage in the upstream stage extend from the exhaust ends of the sub-gas passages in the upstream stage in different directions away from the central intake hole.

7. 7. The electrostatic chuck according to claim 6, wherein the width of the sub gas passage is 0.5 mm or more and 3 mm or less, the depth of the sub gas passage is 0.1 mm or more and 0.4 mm or less, and the number of the sub gas passages is 9 to 100.

8. the sub-gas passage group includes two stages of the sub-gas passage group, each of which is a first stage gas passage group and a second stage gas passage group, the first stage gas passage group includes a plurality of first sub-gas passages, an exhaust end of each of the main gas passages is connected to the intake ends of the three first sub-gas passages, among the three first sub-gas passages connected to the same main gas passage, the intermediate first sub-gas passage is coaxial with the main gas passage, the two first sub-gas passages on both sides are distributed symmetrically with respect to the intermediate first sub-gas passage and connected to different main gas passages, and exhaust ends of any two adjacent first sub-gas passages are joined to form a first common exhaust end, 7. The electrostatic chuck according to claim 6, wherein the second stage gas passage group includes a plurality of second sub-gas passages, and among three of the first sub-gas passages communicating with the same main gas passage, an exhaust end of a middle first sub-gas passage communicates with intake ends of two of the second sub-gas passages, each of the first common exhaust ends communicates with the intake ends of the two second sub-gas passages, and any two adjacent second sub-gas passages communicating with the exhaust ends of the first sub-gas passages and exhaust ends of the second sub-gas passages communicating with the first common exhaust ends join together to form a second common exhaust end, and each of the second common exhaust ends communicates with the annular gas passage.

9. 9. The electrostatic chuck of claim 8, wherein the sub-gas passage group further includes a plurality of transition gas passages, an intake end of each of the transition gas passages communicating with a corresponding one of the second common exhaust ends, and an exhaust end of each of the transition gas passages communicating with the annular gas passage.

10. 4. The electrostatic chuck according to claim 1, wherein a diameter of an annular center line of the annular gas passage is 270 mm or more and 290 mm or less, a radial width of the annular gas passage is 0.5 mm or more and 3 mm or less, and a depth of the annular gas passage is 0.1 mm or more and 0.4 mm or less.

11. 2. The electrostatic chuck of claim 1, wherein the bump structure includes a plurality of bumps evenly distributed within the non-gas passage region, and a ratio of a total area of ​​the orthogonal projection of the plurality of bumps on the upper surface of the chuck body to an area of ​​the upper surface of the chuck body is greater than or equal to 2% and less than or equal to 10%.

12. 12. The electrostatic chuck according to claim 1, wherein the predetermined interval is not less than 2 [mu]m and not more than 10 [mu]m.

13. A semiconductor processing apparatus including a process chamber and an electrostatic chuck provided in the process chamber, the semiconductor processing apparatus using the electrostatic chuck according to any one of claims 1 to 12 as the electrostatic chuck.

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