A lower electrode system

Abstract

The utility model discloses a lower electrode system, include: electrostatic chuck, to bear wafer, pedestal, electrostatic chuck is located on the upper surface of pedestal, lower electrode chamber, set up below the pedestal, insulating isolation component, surround the periphery of pedestal, support pedestal and realize the insulation of pedestal and lower electrode chamber, electrostatic chuck is equipped with the first surface of facing wafer, and this first surface is equipped with the first helium gas inlet area of being located in the central region of electrostatic chuck and the second helium gas inlet area of setting up in the edge region of electrostatic chuck, and is equipped with the first sealing isolation ring between first helium gas inlet area and second helium gas inlet area, helium gas supply component, provide first helium and second helium, helium gas supply component is connected to first helium gas inlet area through first helium pipeline, and is connected to second helium gas inlet area through second helium pipeline, the utility model discloses through the design of partitioned helium, effectively improved the etching uniformity problem of wafer edge region and central region.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor equipment technology, and in particular to a lower electrode system. Background Technology

[0002] In the field of semiconductor device manufacturing, ICP (Inductively Coupled Plasma) deep silicon etching is a key process widely used in the structural fabrication of MEMS (Micro-Electro-Mechanical Systems), power devices, and advanced packaging devices. As devices evolve towards higher integration and precision, increasingly stringent requirements are being placed on the sidewall-to-bottom etching selectivity of the etching profile. This means ensuring the bottom etching rate meets aspect ratio requirements while minimizing the sidewall etching rate to achieve a vertical, smooth, and shape-controllable etching profile. This directly impacts the electrical performance and reliability of the device. Among existing technologies, BIAS bias and low-temperature electrostatic chucks are effective means to achieve high aspect ratio silicon etching. At the hardware structure level, there are differences in hardware conditions between the wafer edge region and the center region, resulting in a significant change in the etching rate or depth of the wafer edge region relative to the center region (i.e., edge effect).

[0003] Therefore, this invention proposes a lower electrode system to address the aforementioned technical problems.

[0004] The statements herein provide only background information relating to this invention and do not necessarily constitute prior art. Utility Model Content

[0005] The purpose of this invention is to provide a lower electrode system that, by setting different helium gas inlet zones on the electrostatic chuck, controls the helium gas introduced through the electrostatic chuck into the central region and the edge region of the back side of the wafer, thereby solving the problem of uneven etching (i.e. edge effect) in the edge and central regions of the wafer.

[0006] To achieve the above objectives, this utility model provides a lower electrode system, comprising: An electrostatic chuck, used to carry a wafer; The base, with the electrostatic chuck located on the upper surface of the base; The lower electrode chamber is located below the base; An insulating isolation component surrounds the base, supports the base, and achieves insulation between the base and the lower electrode chamber; The electrostatic chuck has a first surface facing the wafer, and the first surface has a first helium gas inlet area located in the central region of the electrostatic chuck and a second helium gas inlet area located in the edge region of the electrostatic chuck; wherein, the diameter of the central region accounts for 78% to 82% of the total diameter of the electrostatic chuck; a first sealing isolation ring is provided between the first helium gas inlet area and the second helium gas inlet area; the edge region is the area extending from the edge of the first sealing isolation ring to the outer periphery of the electrostatic chuck. A helium supply assembly is used to supply first helium gas at a first pressure to a first helium gas pipeline and second helium gas at a second pressure to a second helium gas pipeline; the helium supply assembly is connected to the first helium gas inlet area via the first helium gas pipeline; the helium supply assembly is connected to the second helium gas inlet area via the second helium gas pipeline.

[0007] Optionally, the first helium gas inlet area is provided with a plurality of first vent holes on the circumference near the first sealing isolation ring, and the first vent holes are evenly distributed along the circumference. The second helium gas inlet area is defined by an inner circumference and an outer circumference. The second helium gas inlet area is provided with a plurality of second vent holes. The second vent holes are located on a first circumference concentric with the first surface of the electrostatic chuck, and the first circumference is equidistant from the inner and outer circumferences. The second vent holes are evenly distributed along the first circumference.

[0008] Optionally, a second sealing isolation ring is also provided around the outer circumference of the second helium gas inlet area. Both the first sealing isolation ring and the second sealing isolation ring protrude from the first surface of the electrostatic chuck. The ring width of the first sealing isolation ring is smaller than the ring width of the second sealing isolation ring, and the diameter of the second sealing isolation ring is smaller than the diameter of the wafer.

[0009] Optionally, a cantilever extending laterally is provided outside the lower electrode chamber; a chamber opening is provided on one side wall of the lower electrode chamber, and the lower electrode chamber communicates with the cavity inside the cantilever; the first helium pipeline includes a first helium tank and a first helium pipe, the first helium tank being respectively disposed inside the base and the electrostatic chuck; the second helium pipeline includes a second helium tank and a second helium pipe, the second helium tank being respectively disposed inside the base and the electrostatic chuck. The first helium tube passes through the cavity inside the cantilever, extends into the lower electrode cavity through the cavity opening, and communicates with the first helium tank; The second helium tube passes through the cavity inside the cantilever, extends into the lower electrode cavity through the cavity opening, and communicates with the second helium tank.

[0010] Optionally, the first helium tank includes a first annular vent groove embedded in the electrostatic chuck and a first air passage embedded in the base. The first annular vent groove and the first air passage are connected to each other, and the first annular vent groove is located directly below the first vent hole. The second helium tank includes a second annular vent groove embedded in the electrostatic chuck and a second air passage embedded in the base. The second annular vent groove and the second air passage are connected to each other, and the second annular vent groove is located directly below the second vent hole.

[0011] Optionally, the electrostatic chuck is further provided with an electrostatic chuck cooling circuit, which has a planar spiral structure. The cooling circuit is located inside the electrostatic chuck and near the bottom of the electrostatic chuck, and below the first annular vent groove and the second annular vent groove. The lower electrode system also includes a condenser; the condenser is connected to the electrostatic chuck cooling circuit via a refrigerant delivery pipe to provide a cooling medium; the refrigerant delivery pipe passes through the cavity of the cantilever, extends into the lower electrode cavity through the cavity opening, and passes through the base to connect to the electrostatic chuck cooling circuit.

[0012] Optionally, the lower electrode system further includes: The lower electrode chamber heating assembly is disposed around the inner wall of the lower electrode chamber.

[0013] Optionally, the lower electrode system further includes: A compressed air purging pipeline is installed in the lower electrode chamber near the bottom wall of the lower electrode chamber. It is used to output compressed air and to purge the compressed air from bottom to top in the lower electrode chamber.

[0014] Optionally, the lower electrode system further includes: A biased radio frequency and DC module includes a DC transmission conductor and a coaxial radio frequency transmission sleeve sleeved outside the DC transmission conductor; the DC transmission conductor and the radio frequency transmission sleeve pass through the cavity of the cantilever, extend into the lower electrode cavity through the cavity opening, and pass through the base to be electrically connected to the electrostatic chuck; The insulating isolation assembly includes an insulating ring assembly, a grounding ring assembly, and an edge ring assembly; The insulating ring assembly is disposed around the periphery of the base and the electrostatic chuck; The grounding ring assembly is arranged around the periphery of the insulating ring assembly to form a biased radio frequency grounding loop; The edge ring assembly is disposed on the stepped surface of the electrostatic chuck.

[0015] Optionally, the lower electrode system further includes: The wafer lifting assembly includes a support frame, a first drive mechanism, and multiple lifting mechanisms; The support frame is disposed below the base; the first drive mechanism is disposed between the base and the support frame, and the first drive mechanism is mounted on the base; The electrostatic chuck is provided with a plurality of first mounting through holes along its thickness direction, and the base is provided with a plurality of second mounting through holes at positions corresponding to the first mounting through holes; One end of the lifting mechanism is located at the support frame, and the other end extends into the base through the second mounting through hole and passes through the electrostatic chuck through the first mounting through hole. The first drive mechanism is configured to drive the support frame to rise and fall, thereby driving multiple lifting mechanisms to rise and fall along the opening direction of the first mounting through hole through the support frame.

[0016] Optionally, the lower electrode system further includes: The pressure ring lifting assembly includes a second drive mechanism, an actuator, a support ring, and a pressure ring; The second drive mechanism is disposed inside the lower electrode chamber; The actuator includes a guide rod and a moving link, with the lower part of the guide rod located inside the sealed cavity; the sealed cavity is located outside the lower electrode cavity and communicates with the interior of the lower electrode cavity; one end of the moving link located inside the lower electrode cavity is connected to the second drive mechanism, and the other end of the moving link located inside the sealed cavity is connected to the lower part of the guide rod. The bottom of the support ring is connected to the top of the guide rod; the top of the support ring supports the pressure ring; the pressure ring is located above the upper surface of the electrostatic chuck. The second drive mechanism is configured to drive the guide rod to rise and fall via the motion link, thereby driving the rise and fall of the support ring and the pressure ring via the rise and fall of the guide rod.

[0017] In summary, compared with the prior art, the present invention has the following beneficial effects: The present invention provides a lower electrode system that, by setting a first helium gas inlet area and a second helium gas inlet area on an electrostatic chuck, controls the helium gas introduced through the electrostatic chuck into the central and edge areas of the back side of the wafer, thereby solving the problem of uneven etching caused by inconsistent wafer surface temperature during etching. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the lower electrode system of this utility model; Figure 2 This is a schematic diagram of the electrostatic chuck of this utility model; Figure 3This is a three-dimensional structural diagram of the lower electrode system of this utility model. Detailed Implementation

[0019] The following will be combined with the appendix Figures 1-3 The present invention will be further described in detail through preferred embodiments. The advantages and features of the present invention will become clearer from the following description. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, only for the purpose of conveniently and clearly illustrating the embodiments of the present invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of the present invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by the present invention, should still fall within the scope of the technical content disclosed in the present invention.

[0020] This utility model provides a lower electrode system, such as Figure 1 As shown, the lower electrode system includes: an electrostatic chuck 100 for carrying a wafer; a base 200 disposed below the electrostatic chuck 100 for mounting the electrostatic chuck 100; a lower electrode chamber 300 disposed below the base 200 to provide support for the base 200; and an insulating isolation ring assembly 400 surrounding the electrostatic chuck 100 and the base 200, and contacting the edge of the lower surface of the base 200 and the upper surface of the cavity wall of the lower electrode chamber 300 to support the base 200 and achieve insulation between the base 200 and the lower electrode chamber 300.

[0021] See also Figure 1 The lower electrode system also includes a helium supply assembly 800, which is connected to, via a first helium pipe and a second helium pipe, as shown in the figure. Figure 2 The diagram shows a first helium inlet area 810 and a second helium inlet area 820. The first helium inlet area 810 is located in the central region of the first surface of the electrostatic chuck 100 facing the wafer; the second helium inlet area 820 is located in the edge region of the first surface of the electrostatic chuck 100 facing the wafer. The helium supply assembly 800 can supply first helium with a first pressure and second helium with a second pressure to the central region and the edge region of the electrostatic chuck 100, respectively, through the first helium inlet area 810 connected to the first helium pipe and the second helium inlet area 820 connected to the second helium pipe. Further, in a specific embodiment, the first pressure of the first helium is less than the second pressure of the second helium.

[0022] Furthermore, the diameter of the central region accounts for 78% to 82% of the total diameter of the electrostatic chuck 100; a first sealing isolation ring 830 is provided between the first helium gas inlet area 810 and the second helium gas inlet area 820 to isolate the two helium gas inlet areas; the edge region is the area extending from the edge of the first sealing isolation ring 830 to the outer periphery of the electrostatic chuck 100.

[0023] Continue reading Figure 2 The first helium inlet area 810 is provided with a plurality of first vent holes 811 on the circumference near the first sealing isolation ring 830, and the first vent holes 811 are evenly distributed along the circumference 812; after the first helium reaches the first helium inlet area 810, it provides first helium to the inner circle portion on the back side of the wafer through the first vent holes 811, so as to control the temperature of the inner circle portion of the wafer by means of the thermal conductivity of helium; wherein, the inner circle portion of the wafer corresponds to the central area of ​​the electrostatic chuck 100.

[0024] Specifically, the diameter of the circumference 812 is 220mm; in this invention, 10 first vent holes 811 are equally spaced on the circumference 812. The number of first vent holes 811 can be adjusted as needed and is not limited thereto.

[0025] The second helium inlet area 820 is defined by an inner circumference and an outer circumference. The second helium inlet area 820 is provided with a plurality of second vent holes 821. The second vent holes 821 are located on a first circumference 822 concentric with the first surface of the electrostatic chuck 100, and the first circumference 822 is equidistant from the inner and outer circumferences. The second vent holes 821 are evenly distributed along the first circumference 822. After the second helium reaches the second helium inlet area 820, it is supplied to the outer circular portion of the back side of the wafer through the second vent holes 821 to control the temperature of the outer circular portion of the wafer by means of the thermal conductivity of helium. The outer circular portion of the wafer corresponds to the edge region of the electrostatic chuck 100.

[0026] Specifically, the diameter of the first circumference 822 is 270mm; 16 second vent holes 821 are equally spaced on the first circumference 822, and the number of first vent holes 811 can be adjusted as needed, and is not limited thereto; and the first sealing isolation ring 830 is located on the inner circumference.

[0027] During wafer etching, the wafer surface exhibits uneven temperature, particularly between the inner and outer circumferences, with the outer circumference often being hotter than the inner circumference. Therefore, by introducing a second helium gas into the edge region and a first helium gas into the center region of the electrostatic chuck 100, and setting the second helium gas pressure to be greater than the first helium gas pressure, different cooling effects are applied to the edge and center regions of the wafer by adjusting the pressure of the thermally conductive helium gas. This results in a higher density second helium gas flow rate to the outer circumference and a lower density first helium gas flow rate to the inner circumference, thus regulating the wafer surface temperature and achieving a more uniform etching effect.

[0028] Furthermore, a second sealing isolation ring 840 is provided on the outer periphery of the second helium gas inlet area 820. The first sealing isolation ring 830 and the second sealing isolation ring 840 both protrude from the first surface of the electrostatic chuck 100, and the upper ring surfaces of the first sealing isolation ring 830 and the second sealing isolation ring 840 abut against the back side of the wafer to fully isolate the first helium gas and the second helium gas.

[0029] In a specific embodiment of this utility model, the inner ring diameter of the first sealing isolation ring 830 is 245mm, and the outer ring diameter is 247mm, meaning the ring width of the first sealing isolation ring 830 is 1mm; the inner ring diameter of the second sealing isolation ring 840 is 291mm, and the outer ring diameter is 297mm, meaning the ring width of the second sealing isolation ring 840 is 3mm; that is, the ring width of the first sealing isolation ring 830 is smaller than the ring width of the second sealing isolation ring 840; furthermore, the outer ring position of the second sealing isolation ring 840 corresponds to the inner edge of the wafer, meaning the diameter of the second sealing isolation ring 840 is smaller than the diameter of the wafer, thus ensuring that the introduced second helium gas does not leak out and is completely introduced into the outer circumference of the wafer to regulate the temperature of the outer circumference of the wafer.

[0030] The lower electrode chamber 300 is a vacuum-sealed structure, with an atmospheric environment inside and a vacuum environment outside. This lower electrode chamber 300 also provides integrated space for the introduction of HV DC, helium, cooling medium, and heat source.

[0031] The lower electrode chamber 300 is provided with a laterally extending cantilever 310 on its exterior; a chamber opening 311 is provided on one side wall of the lower electrode chamber 300, and the lower electrode chamber 300 and the cavity inside the cantilever 310 are connected through the chamber opening 311.

[0032] The first helium pipeline includes: a first helium tank disposed inside the base 200 and the electrostatic chuck 100; and a first helium tube connected between the bottom of the base 200 and the helium supply assembly 800. The second helium pipeline includes: a second helium tank disposed inside the base 200 and the electrostatic chuck 100; and a second helium tube connected between the bottom of the base 200 and the helium supply assembly 800. The first helium tube passes through the cavity inside the cantilever 310, extends into the lower electrode chamber 300 through the chamber opening 311, and communicates with the first helium tank. The second helium tube passes through the cavity inside the cantilever 310, extends into the lower electrode chamber 300 through the chamber opening 311, and communicates with the second helium tank.

[0033] Furthermore, the first helium tank includes a first annular venting groove 850 embedded in the electrostatic chuck 100 and a first air passage embedded in the base 200, with the first annular venting groove 850 located directly below the first vent hole 811; the second helium tank includes a second annular venting groove 860 embedded in the electrostatic chuck 100 and a second air passage embedded in the base 200, with the second annular venting groove 860 located directly below the second vent hole 821; after reaching the bottom of the base 200, the first helium enters the first air passage and passes through the first air passage directly to the first annular venting groove 850 of the electrostatic chuck 100, and then is discharged through the first vent hole 811; after reaching the bottom of the base 200, the second helium enters the second air passage and passes through the second air passage directly to the second annular venting groove 860 of the electrostatic chuck 100, and then is discharged through the second vent hole 821.

[0034] In addition, the electrostatic chuck 100 is provided with an electrostatic chuck cooling circuit 870, which has a planar spiral structure, is close to the bottom of the electrostatic chuck 100, and is located below the first annular vent groove 850 and the second annular vent groove 860.

[0035] The lower electrode system also includes a condenser 900; the condenser 900 is connected to the electrostatic chuck cooling circuit 870 via a refrigerant delivery pipe 910 to provide a cooling medium; the refrigerant delivery pipe 910 passes through the cavity of the cantilever 310, extends into the lower electrode chamber 300 through the chamber opening 311, and passes through the base 200 to connect to the electrostatic chuck cooling circuit 870; after the cooling medium enters the electrostatic chuck cooling circuit 870, since the cooling circuit pipe has a planar spiral structure, the cooling medium is evenly distributed at the bottom of the electrostatic chuck 100, first achieving uniform cooling at the bottom of the electrostatic chuck 100, and then, under the action of "cold" conduction, the electrostatic chuck 100 cools down from the bottom to the top to stabilize the basic process temperature of the wafer.

[0036] Further, see Figure 3 The lower electrode system further includes: a lower electrode chamber heating assembly 1000, which is arranged around the inner wall of the lower electrode chamber 300; in order to ensure a more uniform heating temperature and faster attainment of the preset temperature in the lower electrode chamber, the present invention provides multiple lower electrode chamber heating assemblies 1000, which are arranged at intervals along the depth direction of the inner wall of the lower electrode chamber 300; the lower electrode chamber 300 maintains the preset temperature to facilitate the desorption of etching byproducts; in a specific embodiment, at least two sets of heating assemblies are arranged around the inner wall of the lower electrode chamber 300.

[0037] Furthermore, the lower electrode system also includes a compressed air purging pipe 1100, which is located in the lower electrode chamber 300 near the bottom wall of the lower electrode chamber, for outputting compressed air and purging the compressed air in the lower electrode chamber 300 from bottom to top to prevent the generation of condensate in the lower electrode chamber 300.

[0038] See also Figure 1 The insulating isolation ring assembly 400 includes an insulating ring assembly 410, a grounding ring assembly 420, and an edge ring assembly 430. The insulating ring assembly 410 is disposed around the base 200 and the electrostatic chuck 100 to provide support and isolate potential for the base 200 and the electrostatic chuck 100. The grounding ring assembly 420 is disposed around the insulating ring assembly 410 to form a biased radio frequency grounding loop and to provide bombardment protection for the insulating ring assembly 410. The edge ring assembly 430 is disposed on the stepped surface of the electrostatic chuck 100 to adjust the electric field distribution and flow field distribution at the edge of the electrostatic chuck 100.

[0039] See also Figure 3 The lower electrode system further includes: a bias RF and DC module 500, which is electrically connected from the outside of the lower electrode chamber 300 to the electrostatic chuck 100 to provide DC and RF current to the lower electrode system; a wafer lifting assembly 600, one end of which is disposed below the base 200 and the other end extends from the bottom of the base 200 to the top of the electrostatic chuck 100 to realize the vertical lifting movement of the wafer above the electrostatic chuck 100; and a pressure ring lifting assembly 700, part of which is disposed outside the lower electrode chamber 300 and the other part is disposed inside the lower electrode chamber 300 to control the lifting of the pressure ring so as to protect the wafer edge by partially shielding the wafer with the pressure ring.

[0040] The bias RF and DC module 500 includes a DC transmission conductor 510 and a coaxial RF transmission sleeve 520 sleeved outside the DC transmission conductor. The DC transmission conductor 510 transmits high-voltage DC electricity, which, when connected to the electrostatic chuck 100, generates electrostatic attraction on the surface of the electrostatic chuck 100 to attract and fix the wafer. The RF transmission sleeve 520 transmits bias RF current, which, when connected to the electrostatic chuck 100, generates a negative bias voltage on the plasma and wafer surface to control the wafer etching process by changing the ion energy. Furthermore, the DC transmission conductor 510 and the RF transmission sleeve 520 pass through the cavity of the cantilever 310, extend into the lower electrode chamber 300 through the chamber opening 311, and pass through the base 200 to be electrically connected to the electrostatic chuck 100.

[0041] Among them, such as Figure 3 As shown, the wafer lifting assembly 600 includes: a support frame 610, which has a C-shaped open ring structure and is disposed below the base 200; a first drive mechanism 620, disposed between the base 200 and the support frame 610, with one end of the first drive mechanism 620 fixedly mounted to the bottom of the base 200 and the other end movably connected to the support frame 610, the first drive mechanism 620 being used to drive the support frame 610 to move up and down in a direction closer to / away from the base 200; and a plurality of lifting mechanisms 630, evenly distributed along the circumferential direction of the C-shaped open ring, the first end of these lifting mechanisms 630 being fixedly connected to the support frame 610, and the second end extending from the bottom of the base 200 to the top of the electrostatic chuck 100, the second ends of these lifting mechanisms 630 being able to contact the back side of the wafer during lifting movement to lift the wafer.

[0042] The electrostatic chuck 100 has multiple first mounting through holes along its thickness direction, i.e., from top to bottom; the base 200 has multiple second mounting through holes along its thickness direction, i.e., from top to bottom; the position of each first mounting through hole corresponds one-to-one with the position of each second mounting through hole; in a specific installation relationship, when one end of each of the multiple lifting mechanisms 630 is fixedly connected to the support frame 610, the other ends of these lifting mechanisms 630 can pass vertically upward through the corresponding second mounting through hole (i.e., extend into the base 200 through the second mounting through hole), and then pass through the electrostatic chuck 100 from the corresponding first mounting through hole.

[0043] Furthermore, the first drive mechanism 620 is configured to drive the support frame 610 to rise and fall, thereby driving multiple lifting mechanisms 630 to rise and fall along the opening direction of the first mounting through hole through the support frame 610, thereby lifting and lowering the wafer.

[0044] The following example illustrates the operation of a wafer lifting assembly 600 according to this application: During wafer lifting operations, the first drive mechanism 620 drives the support frame 610 to move up and down along the thickness direction of the electrostatic chuck. The lifting motion of the support frame 610 is transmitted to multiple lifting mechanisms 630 through its connection point. Each lifting mechanism 630 passes through a second mounting through-hole of the base 200 and a first mounting hole of the electrostatic chuck 100. As the support frame 610 rises and falls, the second end of the lifting mechanism 630 moves up and down along the corresponding first mounting through-hole. When the lifting mechanism 630 rises, its second end extends out of the first mounting through-hole and contacts the back side of the wafer to lift it. When the lifting mechanism 630 falls, its second end retracts into the first mounting through-hole, and the wafer falls to the first surface of the electrostatic chuck 100.

[0045] The pressure ring lifting assembly 700 includes: a second drive mechanism 710, an actuator 720, a support ring 730, and a pressure ring 740; The second drive mechanism 710 is disposed inside the lower electrode chamber 300 and is used to drive the actuator 720; The actuator 720 includes a guide rod 722 and a moving link 721. The lower part of the guide rod 722 is located inside the sealing cavity 723. The sealing cavity 723 is located outside the lower electrode chamber 300 and communicates with the interior of the lower electrode chamber 300. One end of the moving link 721 located inside the lower electrode chamber 300 is connected to the second drive mechanism 710, and the other end of the moving link 721 located inside the sealing cavity 723 is connected to the lower part of the guide rod 722. The moving link 721 can move up and down under the drive of the second drive mechanism 710, thereby driving the guide rod 722 to move up and down along the depth direction of the sealing cavity 723.

[0046] The bottom of the support ring 730 is connected to the top of the guide rod 722; the top of the support ring 730 supports the pressure ring 740; the pressure ring 740 is located above the upper surface of the electrostatic chuck 100.

[0047] Furthermore, the second drive mechanism 710 is configured to drive the guide rod 722 to rise and fall through the motion link 721, thereby driving the rise and fall of the support ring 730 and the pressure ring 740 through the rise and fall of the guide rod 722.

[0048] Furthermore, when the support ring 730 rises from the first height position (initial lowest position) to the third height position (highest position), a certain height space is formed between the pressure ring 740 and the electrostatic chuck 100, which facilitates the placement or removal of the wafer from the electrostatic chuck 100. When the support ring 730 descends from the third height position to the second height position (the second height position is higher than the first height position), the annular surface of the pressure ring 740 falls exactly on the top of the insulating ring assembly 410 and is supported by the insulating ring assembly 410. At this time, the height position of the pressure ring 740 is slightly higher than the wafer placement position, and the vertical projection of the inner ring edge of the pressure ring 740 onto the upper surface of the wafer overlaps exactly with the edge of the wafer. Therefore, it can effectively prevent the wafer edge from being damaged by excessively fast etching rate during the etching process.

[0049] In addition, various cables and pipes are distributed in the lower electrode chamber 300, including the first helium pipe, the second helium pipe, the refrigerant delivery pipe and other transmission cables. These pipes and cables are distributed and fixed along the inner sidewall of the lower electrode chamber 300.

[0050] In summary, the lower electrode system provided by this utility model optimizes the problem of uneven etching due to edge effects by setting a first helium gas inlet area and a second helium gas inlet area on the surface of the electrostatic chuck to control the helium gas introduced into the center region and the bottom edge region of the wafer via the electrostatic chuck.

[0051] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0052] In the description of this utility model, it should be understood that the terms "center," "height," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0053] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0054] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0055] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above content. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A lower electrode system, characterized in that, include: An electrostatic chuck, used to carry a wafer; The base, with the electrostatic chuck located on the upper surface of the base; The lower electrode chamber is located below the base; An insulating isolation component surrounds the base, supports the base, and achieves insulation between the base and the lower electrode chamber; The electrostatic chuck has a first surface facing the wafer, and the first surface has a first helium gas inlet area located in the central region of the electrostatic chuck and a second helium gas inlet area located in the edge region of the electrostatic chuck; wherein, the diameter of the central region accounts for 78% to 82% of the total diameter of the electrostatic chuck; a first sealing isolation ring is provided between the first helium gas inlet area and the second helium gas inlet area; the edge region is the area extending from the edge of the first sealing isolation ring to the outer periphery of the electrostatic chuck. A helium supply assembly is used to supply first helium gas at a first pressure to a first helium gas pipeline and second helium gas at a second pressure to a second helium gas pipeline; the helium supply assembly is connected to the first helium gas inlet area via the first helium gas pipeline; the helium supply assembly is connected to the second helium gas inlet area via the second helium gas pipeline.

2. The lower electrode system as described in claim 1, characterized in that, The first helium gas inlet area is provided with a plurality of first vent holes on the circumference near the first sealing isolation ring, and the first vent holes are evenly distributed along the circumference. The second helium gas inlet area is defined by an inner circumference and an outer circumference. The second helium gas inlet area is provided with a plurality of second vent holes. The second vent holes are located on a first circumference concentric with the first surface of the electrostatic chuck, and the first circumference is equidistant from the inner and outer circumferences. The second vent holes are evenly distributed along the first circumference.

3. The lower electrode system as described in claim 2, characterized in that, A second sealing isolation ring is also provided on the outer periphery of the second helium gas inlet area. Both the first sealing isolation ring and the second sealing isolation ring protrude from the first surface of the electrostatic chuck. The ring width of the first sealing isolation ring is smaller than the ring width of the second sealing isolation ring, and the diameter of the second sealing isolation ring is smaller than the diameter of the wafer.

4. The lower electrode system as described in claim 1, characterized in that, A cantilever extending laterally is provided outside the lower electrode chamber; a chamber opening is provided on one side wall of the lower electrode chamber, and the lower electrode chamber communicates with the cavity inside the cantilever; the first helium pipeline includes a first helium tank and a first helium pipe, the first helium tank being respectively disposed inside the base and the electrostatic chuck; the second helium pipeline includes a second helium tank and a second helium pipe, the second helium tank being respectively disposed inside the base and the electrostatic chuck; The first helium tube passes through the cavity inside the cantilever, extends into the lower electrode cavity through the cavity opening, and communicates with the first helium tank; The second helium tube passes through the cavity inside the cantilever, extends into the lower electrode cavity through the cavity opening, and communicates with the second helium tank.

5. The lower electrode system as described in claim 4, characterized in that, The first helium tank includes a first annular vent groove embedded in the electrostatic chuck and a first air passage embedded in the base. The first annular vent groove and the first air passage are connected to each other. The first annular vent groove is located directly below the first vent hole. The second helium tank includes a second annular vent groove embedded in the electrostatic chuck and a second air passage embedded in the base. The second annular vent groove and the second air passage are connected to each other, and the second annular vent groove is located directly below the second vent hole.

6. The lower electrode system as described in claim 5, characterized in that, The electrostatic chuck is also provided with an electrostatic chuck cooling circuit. The electrostatic chuck cooling circuit has a planar spiral structure. Its cooling circuit is located inside the electrostatic chuck and near the bottom of the electrostatic chuck, and is located below the first annular vent groove and the second annular vent groove. The lower electrode system also includes a condenser; the condenser is connected to the electrostatic chuck cooling circuit via a refrigerant delivery pipe to provide a cooling medium; the refrigerant delivery pipe passes through the cavity of the cantilever, extends into the lower electrode cavity through the cavity opening, and passes through the base to connect to the electrostatic chuck cooling circuit.

7. The lower electrode system as described in claim 6, characterized in that, The lower electrode system also includes: The lower electrode chamber heating assembly is disposed around the inner wall of the lower electrode chamber.

8. The lower electrode system as described in claim 7, characterized in that, The lower electrode system also includes: A compressed air purging pipeline is installed in the lower electrode chamber near the bottom wall of the lower electrode chamber. It is used to output compressed air and to purge the compressed air from bottom to top in the lower electrode chamber.

9. The lower electrode system as described in claim 3, characterized in that, The lower electrode system further includes: A biased radio frequency and DC module includes a DC transmission conductor and a coaxial radio frequency transmission sleeve sleeved outside the DC transmission conductor; the DC transmission conductor and the radio frequency transmission sleeve pass through the cavity of the cantilever, extend into the lower electrode cavity through the cavity opening, and pass through the base to be electrically connected to the electrostatic chuck; The insulating isolation assembly includes an insulating ring assembly, a grounding ring assembly, and an edge ring assembly; The insulating ring assembly is disposed around the periphery of the base and the electrostatic chuck; The grounding ring assembly is arranged around the periphery of the insulating ring assembly to form a biased radio frequency grounding loop; The edge ring assembly is disposed on the stepped surface of the electrostatic chuck.

10. The lower electrode system as claimed in claim 1, characterized in that, The lower electrode system further includes: A wafer lifting assembly includes a support frame, a first drive mechanism, and multiple lifting mechanisms. The support frame is disposed below the base; the first drive mechanism is disposed between the base and the support frame, and the first drive mechanism is mounted on the base; The electrostatic chuck is provided with a plurality of first mounting through holes along its thickness direction, and the base is provided with a plurality of second mounting through holes at positions corresponding to the first mounting through holes; One end of the lifting mechanism is located at the support frame, and the other end extends into the base through the second mounting through hole and passes through the electrostatic chuck through the first mounting through hole. The first drive mechanism is configured to drive the support frame to rise and fall, thereby driving multiple lifting mechanisms to rise and fall along the opening direction of the first mounting through hole through the support frame.

11. The lower electrode system as claimed in claim 1, characterized in that, The lower electrode system further includes: The pressure ring lifting assembly includes a second drive mechanism, an actuator, a support ring, and a pressure ring; The second drive mechanism is disposed inside the lower electrode chamber; The actuator includes a guide rod and a moving link, with the lower part of the guide rod located inside the sealed cavity; the sealed cavity is located outside the lower electrode cavity and communicates with the interior of the lower electrode cavity; one end of the moving link located inside the lower electrode cavity is connected to the second drive mechanism, and the other end of the moving link located inside the sealed cavity is connected to the lower part of the guide rod. The bottom of the support ring is connected to the top of the guide rod; the top of the support ring supports the pressure ring; The pressure ring is located above the upper surface of the electrostatic chuck; The second drive mechanism is configured to drive the guide rod to rise and fall via the motion link, thereby driving the rise and fall of the support ring and the pressure ring via the rise and fall of the guide rod.

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