A lower electrode assembly

Abstract

This utility model discloses a lower electrode assembly, comprising: a lower electrode including a metal base and an electrostatic chuck disposed on the metal base; the electrostatic chuck is used to adsorb a wafer placed thereon; an insulating isolation component surrounding the periphery of the lower electrode and contacting the edge of the lower surface of the lower electrode to support the lower electrode; a grounding component surrounding the periphery of the insulating isolation component; and a lower electrode cavity wall supporting the insulating isolation component and the grounding component. The lower electrode assembly provided by this utility model can solve the problems of unstable RF bias introduction, uneven wafer etching, and poor edge isolation protection existing in the current ICP etching process.

Description

Technical Field

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

[0002] In the manufacturing process of semiconductor devices, inductively coupled plasma (ICP) etching technology, as a key patterning transfer process, is widely used for the high-precision and high-selectivity removal of materials from wafer surfaces. The core of this technology lies in using radio frequency (RF) energy to excite gas to form plasma, and utilizing a radio frequency bias (BIAS RF) system to control the bombardment energy and direction of charged particles in the plasma on the wafer surface, thereby achieving precise control over etching rate, uniformity, and anisotropy.

[0003] As semiconductor devices develop towards higher integration and smaller feature sizes, the requirements for ICP etching processes are becoming increasingly stringent, especially in the following aspects:

[0004] First, the stability and reliability of the RF bias system are fundamental to ensuring etching quality. This system must simultaneously achieve an effective cathode structure (to transfer RF bias energy to the wafer) and a properly constructed grounding loop (to ensure stable RF energy return). Furthermore, strict electrical isolation between the cathode and the grounding loop is crucial to prevent RF energy leakage, short circuits, or interference. Otherwise, issues such as etching rate fluctuations and wafer surface charge accumulation can occur, severely impacting device performance.

[0005] Secondly, the adjustability of the etching rate in the wafer edge region is an important performance indicator for the equipment. Compared to the inner region of the wafer, there are significant differences in the etching rate and profile perpendicularity at the wafer edge. Therefore, establishing the ability to regulate the electric field, flow field, and temperature at the edge is of great significance for improving the edge etching rate and profile perpendicularity.

[0006] Furthermore, protection of wafer edges and ESC (electrostatic chuck) edges is crucial. Plasma is highly corrosive; direct bombardment of wafer or ESC edges can lead to over-etching of wafer edge materials, damage to the ESC surface, or shortened lifespan, increasing production costs and affecting process stability. In existing structures, insufficient design of protective components or inadequate isolation often fails to effectively prevent plasma erosion of edge areas.

[0007] Currently, existing structural designs around electrodes under ICP etching often fail to simultaneously meet the comprehensive requirements of the aforementioned RF bias system, including cathode configuration, ground loop construction, effective isolation, electric field optimization, wafer edge protection, and ESC edge protection. While some structures can achieve a single function (such as isolation or protection), they have shortcomings in multi-functional coordination. For example, the isolation between the ground loop and the cathode relies on a single insulating component, which is prone to isolation failure due to material aging or plasma erosion; electric field optimization relies solely on simple metal ring adjustments, making it difficult to precisely control the electric field distribution at the wafer edge; and wafer and ESC edge protection lack multi-level barrier designs, resulting in limited protective effectiveness.

[0008] Therefore, developing a structure around the electrode in ICP etching that integrates the above-mentioned multiple functions and ensures good cooperation among the components is of great significance for improving the stability, uniformity, and equipment lifespan of the ICP etching process and meeting the needs of advanced semiconductor manufacturing.

[0009] The statements herein provide only background information relating to this invention and do not necessarily constitute prior art. Utility Model Content

[0010] The purpose of this invention is to provide a lower electrode assembly that can solve the problems of unstable RF bias introduction, uneven wafer etching, and poor edge isolation protection in existing ICP etching processes.

[0011] To achieve the above objectives, this utility model provides a lower electrode assembly, comprising:

[0012] The lower electrode includes a metal base and an electrostatic chuck disposed on the metal base; the electrostatic chuck is used to adsorb the wafer placed thereon.

[0013] An insulating isolation component surrounds the periphery of the lower electrode and contacts the edge of the lower surface of the lower electrode to support the lower electrode;

[0014] A grounding component is disposed around the periphery of the insulating isolation component;

[0015] The lower electrode cavity wall supports the insulating isolation component and the grounding component.

[0016] Optionally, the insulating isolation component includes:

[0017] The lower ceramic ring is located on the inner side of the top of the lower electrode cavity wall, surrounds the periphery of the metal base, and supports the bottom edge of the metal base;

[0018] The first quartz ring is located on the lower ceramic ring and is arranged around the periphery of the metal base and the electrostatic chuck;

[0019] The second quartz ring is located on the first quartz ring and is arranged around the periphery of the electrostatic chuck;

[0020] The upper ceramic pressure ring is located on the second quartz ring.

[0021] Optionally, a recessed electrostatic chuck step is provided at the edge of the upper surface of the electrostatic chuck;

[0022] The lower electrode assembly also includes an adjustment component, which is disposed on the electrostatic chuck step and surrounded by the first quartz ring and the second quartz ring; the outer periphery of the adjustment component has gaps between it and the inner wall of the first quartz ring and the inner wall of the second quartz ring.

[0023] Optionally, the top of the second quartz ring is provided with multiple continuous steps, which are distributed radially and gradually increase from the inside to the outside of the second quartz ring;

[0024] The adjustment component includes:

[0025] A base ring is disposed on the step of the electrostatic chuck and is surrounded by the first quartz ring and the second quartz ring; the upper surface of the base ring is flush with the step surface of the innermost step at the top of the second quartz ring;

[0026] An edge ring is disposed on the surface formed by the innermost step at the top of the base ring and the second quartz ring.

[0027] Optionally, the base ring is a metal base ring, and the surface of the metal base ring that contacts the electrostatic chuck step is provided with an anodic oxide film; gaps are left between the outer periphery of the base ring and the inner wall of the first quartz ring and the inner wall of the second quartz ring.

[0028] Optionally, the multi-level continuous steps further include a second level step connected to the innermost step;

[0029] The upper surface of the edge ring is flush with the step surface of the second step at the top of the second quartz ring;

[0030] The edge ring has a gap between the side of the second quartz ring and the side wall from the innermost step to the second step; the edge ring has a notch structure on the other side of the electrostatic chuck.

[0031] Optionally, the grounding component includes:

[0032] The lower grounding ring is located on the outer region of the top of the lower electrode cavity wall and is arranged around the periphery of the lower ceramic ring and the first quartz ring; and the inner wall of the lower grounding ring has gaps with the periphery of the lower ceramic ring and the periphery of the first quartz ring.

[0033] The inner liner has one end located between the lower grounding ring and the upper grounding ring, surrounding the periphery of the first quartz ring, and leaving a gap with the periphery of the first quartz ring; the other end of the inner liner extends radially outward and upward into the cavity.

[0034] The upper grounding ring is arranged around the periphery of the first quartz ring; and the inner wall of the upper grounding ring has a gap with the periphery of the first quartz ring.

[0035] Optionally, the top of the upper ceramic pressure ring is provided with:

[0036] An inclined surface is radially inclined from the outside to the inside of the upper ceramic pressure ring, with the outer edge of the inclined surface being higher than the inner edge of the inclined surface.

[0037] The first upper ceramic pressure ring plane extends horizontally outward from the outer edge of the inclined surface to the outer side wall of the upper ceramic pressure ring;

[0038] The second upper ceramic pressure ring plane extends inward from the inner edge of the inclined surface.

[0039] Optionally, the bottom of the upper ceramic pressure ring is provided with a first fitting and limiting structure;

[0040] The first fitting limiting structure is fitted into the outermost step at the top of the second quartz ring.

[0041] Optionally, the first fitting and limiting structure at the bottom of the upper ceramic pressure ring is a concave ring, which fits into the convex ring formed by the outermost step at the top of the second quartz ring.

[0042] Optionally, the bottom of the second quartz ring is provided with a second fitting limiting structure, and the top of the first quartz ring is provided with a third fitting limiting structure; the bottom of the second quartz ring and the top of the first quartz ring are installed by the cooperation of the second fitting limiting structure and the third fitting limiting structure.

[0043] Optionally, the inner bottom of the second quartz ring is provided with a first raised step that protrudes relative to the outer bottom, and the inner top of the first quartz ring is provided with a first recessed step that is recessed relative to the outer top.

[0044] The plane at the bottom outer side of the second quartz ring abuts against the plane at the top outer side of the first quartz ring, and the first protruding step at the bottom inner side of the second quartz ring is fitted into the first recessed step at the top inner side of the first quartz ring.

[0045] Optionally, the bottom of the first quartz ring is provided with a fourth fitting and limiting structure, the top of the lower ceramic ring is provided with a fifth fitting and limiting structure, and the edge of the lower surface of the metal base is provided with a sixth fitting and limiting structure.

[0046] The bottom of the first quartz ring, the lower surface of the metal base, and the top of the lower ceramic ring are installed by the cooperation of the fourth, sixth, and fifth fitting limiting structures.

[0047] Optionally, the inner bottom of the first quartz ring is provided with a second recessed step that is recessed relative to the outer bottom; the middle top of the lower ceramic ring is provided with a second raised step that is raised relative to the outer top; the inner top of the lower ceramic ring is provided with a third recessed step that is recessed relative to the middle top; and a recessed metal base step is provided at the edge of the lower surface of the metal base.

[0048] The outer bottom plane of the first quartz ring abuts against the outer top plane of the lower ceramic ring. The second protruding step at the middle top of the lower ceramic ring is fitted into the second recessed step at the inner bottom of the first quartz ring and the metal base step. The outer edge of the lower surface of the metal base is fitted into the third recessed step at the inner top of the lower ceramic ring.

[0049] Optionally, the bottom of the lower ceramic ring is provided with a seventh fitting limiting structure, and the top of the lower electrode cavity wall is provided with an eighth fitting limiting structure; the bottom of the lower ceramic ring and the top of the lower electrode cavity wall are installed by the cooperation of the seventh fitting limiting structure and the eighth fitting limiting structure.

[0050] Optionally, the inner bottom of the lower ceramic ring is provided with a third raised step that protrudes relative to the outer bottom; the inner top of the lower electrode cavity wall is provided with a fourth recessed step that is recessed relative to the outer top.

[0051] The outer bottom plane of the lower ceramic ring abuts against the outer top plane of the lower electrode cavity wall, and the third protruding step of the inner bottom of the lower ceramic ring is fitted into the fourth recessed step of the inner top of the lower electrode cavity wall.

[0052] Optionally, the bottom of the upper ceramic pressure ring contacts the top of the second quartz ring to form a fitting gap, and the minimum cumulative distance from the inner wall of the second quartz ring along the fitting gap to the outer wall of the second quartz ring is greater than or equal to 20 mm.

[0053] Optionally, the bottom of the second quartz ring contacts the top of the first quartz ring to form a fitting gap, and the minimum cumulative distance from the inner wall of the first quartz ring along the fitting gap to the outer wall of the first quartz ring is greater than or equal to 20 mm.

[0054] Optionally, the bottom of the first quartz ring contacts the top of the lower ceramic ring to form a fitting gap, and the minimum cumulative distance from the inner wall of the lower ceramic ring along the fitting gap to the contact surface of the outer wall of the lower ceramic ring is greater than or equal to 20 mm.

[0055] Optionally, the radial distance between the inner edge of the upper ceramic pressure ring and the edge of the wafer is 1 to 1.5 mm.

[0056] Optionally, an O-ring is disposed on the electrostatic chuck at a position where it contacts the edge ring and the base ring;

[0057] The top plane of the O-ring is lower than the bottom wall of the notch structure of the edge ring, and the bottom plane of the O-ring is lower than the upper surface of the base ring, so as to form a misaligned structure to protect the electrostatic chuck.

[0058] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0059] 1. The lower electrode assembly provided by this utility model effectively constructs a cathode structure (to transfer radio frequency bias energy to the wafer) and a grounding loop (to ensure stable return of radio frequency energy), thereby ensuring the quality of wafer etching through the stability of the radio frequency bias system.

[0060] 2. The lower electrode assembly provided by this utility model effectively improves the edge etching effect of the wafer by setting the bias electrode and the adjustment assembly.

[0061] 3. The lower electrode assembly provided by this utility model, through the setting of the insulating isolation component, avoids the direct bombardment of the wafer edge or ESC edge by plasma, thereby avoiding excessive etching of the wafer edge material, damage to the ESC surface or shortened life, thus reducing production costs and improving process stability. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of the structure of the lower electrode assembly of this utility model;

[0063] Figure 2 This is a schematic diagram of the structure and installation of the insulating isolation component and the adjusting component of this utility model;

[0064] Figure 3 This is a magnified view of a portion of the structure of the adjustment component, the connection between the O-ring and the electrostatic chuck of this utility model;

[0065] Figure 4 This is a schematic diagram showing the connection between the lower electrode, liner, and chamber of this utility model. Detailed Implementation

[0066] The following will be combined with the appendix Figures 1-4The 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.

[0067] This utility model provides a lower electrode assembly, which can be disposed as follows: Figure 4 On the semiconductor chamber 100 shown. As... Figure 1 As shown, the lower electrode assembly includes: a lower electrode comprising a metal base 110 and an electrostatic chuck 120 disposed on the metal base 110; an insulating isolation component 200 surrounding the periphery of the lower electrode and contacting the edge of the lower surface of the lower electrode to provide support for the lower electrode and isolate plasma; a grounding component 300 surrounding the periphery of the insulating isolation component 200 to provide a stable grounding loop for the radio frequency bias system and to provide protection for the insulating isolation component 200; and a lower electrode cavity wall 400 disposed below the insulating isolation component 200 and the grounding component 300 and providing support.

[0068] In addition, the lower electrode assembly also includes a radio frequency (RF) module 500, electrically connected below the lower electrode to provide an RF bias voltage. The RF module 500 is connected to the electrostatic chuck 120 via a metal base 110, forming the cathode of the RF bias system.

[0069] Optionally, the RF module 500 can also be connected to the bottom wall of the metal base 110 by an external circuit and then led to the electrostatic chuck 120 to provide RF bias voltage.

[0070] The grounding component 300 is electrically connected to the lower electrode cavity wall 400, forming part of the grounding electrode of the radio frequency bias system.

[0071] The electrostatic chuck 120 generates electrostatic force to attract and fix the wafer 700 placed on it. The electrostatic chuck 120 is embedded with HV DC (high voltage direct current) electrodes, heating electrodes, helium gas channels, coolant channels, etc., and HV DC, helium gas, coolant, and heat source are introduced into the electrostatic chuck 120 through the metal base 110.

[0072] Furthermore, the lower electrode cavity wall 400, the lower ceramic ring 210, and the metal base 110 surround and form the lower electrode chamber, which is a vacuum-sealed structure with an atmospheric interior and a vacuum exterior. This lower electrode chamber also provides integrated space for the introduction of HV DC, helium, coolant, and heat sources.

[0073] Among them, such as Figure 2 As shown, the insulating isolation assembly 200 is stacked sequentially from bottom to top in the direction away from the lower electrode cavity wall: a lower ceramic ring 210, located on the inner side of the top of the lower electrode cavity wall 400, surrounding the periphery of the metal base 110 and supporting the bottom edge of the metal base 110; a first quartz ring 220, located on the lower ceramic ring 210 and surrounding the periphery of the metal base 110 and the electrostatic chuck 120, to further isolate plasma leaking from the edge of the grounding assembly and provide electrical insulation protection; a second quartz ring 230, located on the first quartz ring 220 and surrounding the periphery of the electrostatic chuck 120, to prevent plasma from entering; and an upper ceramic pressure ring 240, located on the second quartz ring 230, the inner edge of which presses against the edge of the wafer 700 to prevent damage to the edge of the wafer 700 during etching.

[0074] Specifically, such as Figure 2 As shown, the insulating isolation assembly 200 is installed sequentially from bottom to top, starting from the upper end face (i.e., the top of the lower electrode cavity wall) of the lower electrode cavity wall 400: A lower ceramic ring 210 is fixedly installed on the upper end face of the lower electrode cavity wall 400, forming a sealed connection through fastening, and achieving concentric constraint through the inner annular stepped surface. A metal base 110 is installed on the upper end face of the lower ceramic ring 210, forming a sealed connection through fastening, and achieving concentric constraint through the annular stepped surface. A first quartz ring 220 is mounted on the upper end face of the lower ceramic ring 210, achieving concentric constraint through the annular stepped surface. A second quartz ring 230 is mounted on the upper end face of the first quartz ring 220, achieving concentric constraint through the annular stepped surface. An upper ceramic pressure ring 240 is mounted on the upper end face of the second quartz ring 230, achieving concentric constraint through the annular stepped surface.

[0075] Furthermore, the height and mating surface positions of the insulating isolation assembly 200 are configured as follows from bottom to top: the mating surface of the first quartz ring 220 and the lower ceramic ring 210 is located at the midpoint of the thickness of the metal base 110. The first quartz ring 220 extends downwards at its bottom position beyond the mating surface of the metal base 110 and the electrostatic chuck 120, and extends upwards at its top position beyond the mating surface of the electrostatic chuck 120 and the base ring 610. The mating surface of the second quartz ring 230 and the upper ceramic pressure ring 240 is located at the midpoint of the thickness of the base ring 610. The structural dimensions and mating method of the lower ceramic ring 210, the first quartz ring 220, the second quartz ring 230, and the upper ceramic pressure ring 240 effectively block the creepage path between the inner metal base 110 and the electrostatic chuck 120 and the outer grounding assembly 300, while simultaneously achieving concentric assembly and improving the uniformity of the electric field and flow field in the circumferential direction.

[0076] The grounding assembly 300 comprises, from bottom to top, the following components arranged in a manner away from the lower electrode cavity wall: a lower grounding ring 310, located on the outer region of the top of the lower electrode cavity wall 400 and surrounding the lower ceramic ring 210 and the first quartz ring 220; an inner liner 320, surrounding the first quartz ring 220, with one end of the inner liner 320 located between the lower grounding ring 310 and the upper grounding ring 330, and the other end of the inner liner 320 extending radially outward and upward into the cavity to block and surround the plasma; and an upper grounding ring 330, surrounding the first quartz ring 220 to shield the plasma and prevent it from bombarding and damaging the insulating isolation assembly 200.

[0077] Specifically, the grounding assembly 300 is installed on the top of the lower electrode cavity wall 400, outside the insulating isolation assembly 200, and corresponds to the electrostatic chuck 120, forming two electrodes for a bias electric field. The grounding assembly 300 is arranged sequentially from bottom to top: a lower grounding ring 310, installed on the upper end face of the lower electrode cavity wall 400, with the two achieving a reliable and uniform conductive connection through an induction coil; an inner liner 320, located at the bottom center, mates with the upper end face of the lower grounding ring 310, forming a reliable and uniform conductive connection through an induction coil; and an inner liner 320, located at the top edge, mates with the recessed platform on the upper end face of the chamber 100, forming a reliable and uniform conductive connection through an induction coil, and simultaneously forming a concentric constraint through the recessed platform. The grounding assembly 300 also shields against plasma, protecting the internal insulating isolation assembly from plasma corrosion.

[0078] Preferably, the inner wall of the lower grounding ring 310 has gaps with the outer periphery of the lower ceramic ring 210 and the outer periphery of the first quartz ring 220; the end of the inner liner 320 near the first quartz ring 220 has a gap with the outer periphery of the first quartz ring 220; the inner wall of the upper grounding ring 330 also has a gap with the outer periphery of the first quartz ring 220. The arrangement of these gaps takes into account that the dimensions of the lower grounding ring 310, the inner liner 320, the upper grounding ring 330 and the adjacent first quartz ring 220 and second quartz ring 230 may change due to changes in environment and operating temperature, so as to provide a design protection.

[0079] The lower electrode assembly further includes an adjustment component 600, which is disposed in the gap structure formed by the electrostatic chuck 120, the first quartz ring 220, and the second quartz ring 230. The adjustment component 600 is used to adjust the electric field distribution and temperature transfer efficiency at the edge of the electrostatic chuck 120. Specifically, a recessed electrostatic chuck step 121 is provided at the edge of the upper surface of the electrostatic chuck 120, and the adjustment component 600 is disposed on the electrostatic chuck step 121 and surrounded by the first quartz ring 220 and the second quartz ring 230.

[0080] Preferably, a gap is left between the outer periphery of the adjustment component 600 and the inner wall of the first quartz ring 220 and the inner wall of the second quartz ring 230. The gap is set to take into account that the size of the adjustment component 600, the first quartz ring 220 and the second quartz ring 230 may change due to changes in the environment and operating temperature, so as to provide a design protection.

[0081] Among them, such as Figure 2 As shown, the adjustment assembly 600 includes: a base ring 610 disposed on the electrostatic chuck step 121 and surrounded by the first quartz ring 220 and the second quartz ring 230; and an edge ring 620 comprising an integrally formed inner ring portion and an outer ring portion, wherein the inner ring portion of the edge ring 620 is disposed on the base ring 610 and the outer ring portion is disposed on the second quartz ring 230.

[0082] Furthermore, the top of the second quartz ring 230 is provided with multiple continuous steps, which are distributed radially and gradually increase from the inside to the outside of the second quartz ring 230; the multiple continuous steps also include a second step connected to the innermost step.

[0083] Furthermore, the upper surface of the base ring 610 is flush with the step surface of the innermost step at the top of the second quartz ring 230; the inner ring portion and the outer ring portion of the edge ring 620 are respectively located on the innermost step at the top of the base ring 610 and the second quartz ring 230, that is, the edge ring 620 is disposed on the surface jointly formed by the innermost step at the top of the base ring 610 and the second quartz ring 230.

[0084] The upper surface of the edge ring 620 is flush with the step surface of the second step at the top of the second quartz ring 230.

[0085] Preferably, the edge ring 620 has a gap between its side closest to the second quartz ring 230 and the sidewall between the innermost step and the second step. The edge ring 620 has a notch structure 621 on its upper edge near the other side of the electrostatic chuck 120. This notch structure 621 has a stepped structure, i.e., it has circumferentially arranged sidewalls and a bottom wall. Both the bottom wall and sidewalls of the notch structure 621 have gaps with the edge of the wafer 700. The presence of these gaps improves gas flow at the edge of the wafer 700, reduces heat radiation conduction from the edge ring 620, and thus improves heat conduction on the upper surface of the wafer 700 and the uniformity of edge etching. Simultaneously, the gaps also ensure a safe distance between the wafer 700 and the edge ring 620, preventing direct contact between the radio frequency and the wafer 700.

[0086] Furthermore, such as Figure 3 As shown, an O-ring 800 is also provided on the electrostatic chuck 120 at the position where it contacts the edge ring 620 and the base ring 610. The O-ring 800 is used to protect the adhesive layer of the electrostatic chuck 120 and prevent the adhesive material therein from being etched, which would damage the performance of the electrostatic chuck 120. The top plane of the O-ring 800 is lower than the bottom wall of the notch structure 621 of the edge ring 620, and the bottom plane of the O-ring 800 is lower than the upper surface of the base ring 610, so as to form a misaligned structure to reduce plasma from entering the O-ring 800.

[0087] In a specific embodiment of this utility model, the base ring 610 is a metal base ring, and the surface of the metal base ring that contacts the electrostatic chuck step 121 is provided with an anodic oxide film; therefore, a radio frequency coupling connection is formed between the metal base ring and the electrostatic chuck 120 to expand the edge range of the radio frequency bias.

[0088] The edge ring 620 is made of silicon carbide (SIC) or other materials with low resistivity to serve as an extension of the cathode in the radio frequency bias system, thereby improving the edge electric field of the wafer 700.

[0089] Preferably, a gap is left between the outer periphery of the base ring 610 and the inner wall of the first quartz ring 220 and the inner wall of the second quartz ring 230. The gap is designed to take into account that the dimensions of the base ring 610, the first quartz ring 220 and the second quartz ring 230 may change due to changes in the environment and operating temperature, so as to provide a design protection.

[0090] The top of the upper ceramic pressure ring 240 is provided with: an inclined surface 241, which is radially inclined from the outside to the inside of the upper ceramic pressure ring 240, and the outer edge of the inclined surface 241 is higher than the inner edge of the inclined surface to facilitate the passage of airflow above the inclined surface, thereby improving the uniformity of edge etching; a first upper ceramic pressure ring plane, which extends horizontally outward from the outer edge of the inclined surface 241 to the outer wall of the upper ceramic pressure ring 240; and a second upper ceramic pressure ring plane 242, which extends inward from the inner edge of the inclined surface 241 and covers the edge of the wafer 700.

[0091] Preferably, the radial distance between the inner edge of the upper ceramic retaining ring 240 and the edge of the wafer is 1 to 1.5 mm. The second upper ceramic retaining ring plane 242 presses against the edge of the wafer 700 by a certain dimension to achieve edge protection of the wafer during deep silicon etching.

[0092] The bottom of the upper ceramic pressure ring 240 and the top of the second quartz ring 230 are connected by a fitting structure. Specifically, the bottom of the upper ceramic pressure ring 240 is provided with a first fitting limiting structure, which is fitted into the outermost step of the top of the second quartz ring 230.

[0093] More specifically, the first fitting and limiting structure at the bottom of the upper ceramic pressure ring 240 is a concave ring, which fits into the convex ring formed by the outermost step at the top of the second quartz ring 230.

[0094] The bottom of the second quartz ring 230 and the top of the first quartz ring 220 are connected by a fitting structure. Specifically, the bottom of the second quartz ring 230 is provided with a second fitting limiting structure, and the top of the first quartz ring 220 is provided with a third fitting limiting structure. The bottom of the second quartz ring 230 and the top of the first quartz ring 220 are installed by the cooperation of the second fitting limiting structure and the third fitting limiting structure.

[0095] More specifically, the inner bottom of the second quartz ring 230 is provided with a first protruding step 231 that protrudes relative to the outer bottom, and the inner top of the first quartz ring 220 is provided with a first recessed step that is recessed relative to the outer top.

[0096] Furthermore, the plane of the outer bottom of the second quartz ring 230 abuts against the plane of the outer top of the first quartz ring 220, and the first protruding step 231 of the inner bottom of the second quartz ring 230 is fitted into the first recessed step of the inner top of the first quartz ring 220. Moreover, the protruding contour of the first protruding step 231 matches the concave contour of the first recessed step, allowing the first protruding step 231 to be precisely embedded within the first recessed step.

[0097] The bottom of the first quartz ring 220, the top of the lower ceramic ring 210, and the edge of the lower surface of the metal base 110 are connected by a fitting structure; specifically:

[0098] The first quartz ring 220 has a fourth fitting and limiting structure at its bottom, the lower ceramic ring 210 has a fifth fitting and limiting structure at its top, and the metal base 110 has a sixth fitting and limiting structure at its lower surface edge.

[0099] The bottom of the first quartz ring 220, the lower surface of the metal base 110, and the top of the lower ceramic ring 210 are installed together by the cooperation of the fourth, sixth, and fifth fitting limiting structures.

[0100] More specifically, the inner bottom of the first quartz ring 220 is provided with a second recessed step that is recessed relative to the outer bottom; the middle top of the lower ceramic ring 210 is provided with a second raised step 211 that is raised relative to the outer top; the inner top of the lower ceramic ring 210 is provided with a third recessed step that is recessed relative to the middle top; and a recessed metal base step 111 is provided at the edge of the lower surface of the metal base 110.

[0101] Furthermore, the outer bottom plane of the first quartz ring 220 abuts against the outer top plane of the lower ceramic ring 210. The second protruding step 211 at the middle top of the lower ceramic ring 210 is fitted into the second recessed step at the inner bottom of the first quartz ring 220 and the metal base step 111. The outer edge of the lower surface of the metal base 110 is fitted into the third recessed step at the inner top of the lower ceramic ring 210. Moreover, the protruding profile of the second protruding step 211 perfectly matches the recessed profile formed by the second recessed step and the metal base step 111, thus allowing the second protruding step 211 to be precisely embedded within the recessed structure formed by the second recessed step and the metal base step 111. The outer edge profile of the lower surface of the metal base 110 matches the recessed profile of the third recessed step, thus allowing the outer edge of the lower surface of the metal base 110 to be precisely embedded within the third recessed step.

[0102] The bottom of the lower ceramic ring 210 and the top of the lower electrode cavity wall 400 are connected by a fitting structure. Specifically, the bottom of the lower ceramic ring 210 is provided with a seventh fitting limiting structure, and the top of the lower electrode cavity wall 400 is provided with an eighth fitting limiting structure. The bottom of the lower ceramic ring 210 and the top of the lower electrode cavity wall 400 are installed by the cooperation of the seventh and eighth fitting limiting structures.

[0103] More specifically, the inner bottom of the lower ceramic ring 210 is provided with a third protruding step 212 that protrudes relative to the outer bottom; the inner top of the lower electrode cavity wall 400 is provided with a fourth recessed step that is recessed relative to the outer top.

[0104] The outer bottom plane of the lower ceramic ring 210 abuts against the outer top plane of the lower electrode cavity wall 400, and the third protruding step 212 on the inner bottom of the lower ceramic ring 210 is fitted into the fourth recessed step on the inner top of the lower electrode cavity wall 400. Furthermore, the protruding contour of the third protruding step 212 is perfectly matched with the concave contour of the fourth recessed step, so that the third protruding step 212 can be perfectly embedded in the fourth recessed step.

[0105] In a specific embodiment of this utility model, the bottom of the upper ceramic pressure ring 240 contacts the top of the second quartz ring 230 to form a fitting gap, and the minimum cumulative distance from the inner wall of the second quartz ring 230 along the fitting gap to the outer wall of the second quartz ring 230 is greater than or equal to 20mm; the fitting gap is in the form of a bent structure, and the existence of this fitting gap structure improves the high voltage arc resistance performance of the second quartz ring 230 and reduces the risk of creepage.

[0106] The bottom of the second quartz ring 230 contacts the top of the first quartz ring 220 to form a fitting gap. The minimum cumulative distance from the inner wall of the first quartz ring 220 along the fitting gap to the outer wall of the first quartz ring 220 is greater than or equal to 20mm. The fitting gap is in the form of a bent structure. The existence of this fitting gap structure improves the high voltage arc resistance of the first quartz ring 220 and reduces the risk of creepage.

[0107] The bottom of the first quartz ring 220 contacts the top of the lower ceramic ring 210 to form a fitting gap. The minimum cumulative distance from the inner wall of the lower ceramic ring 210 along the fitting gap to the contact surface of the outer wall of the lower ceramic ring 210 is greater than or equal to 20mm. The fitting gap is in the form of a bent structure. The existence of this fitting gap structure improves the high voltage arc resistance of the lower ceramic ring 210 and reduces the risk of creepage.

[0108] In summary, the lower electrode assembly provided by this utility model has the advantages of a stable and reliable radio frequency bias system, excellent wafer edge etching effect, and strong protection capability for wafer edges and electrostatic chuck (ESC) edges.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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 assembly, characterized in that, include: The lower electrode includes a metal base and an electrostatic chuck disposed on the metal base; The electrostatic chuck is used to pick up the wafer placed on it; An insulating isolation component surrounds the periphery of the lower electrode and contacts the edge of the lower surface of the lower electrode to support the lower electrode; A grounding component is disposed around the periphery of the insulating isolation component; The lower electrode cavity wall supports the insulating isolation component and the grounding component.

2. The lower electrode assembly as described in claim 1, characterized in that, The insulating component includes: The lower ceramic ring is located on the inner side of the top of the lower electrode cavity wall, surrounds the periphery of the metal base, and supports the bottom edge of the metal base; The first quartz ring is located on the lower ceramic ring and is arranged around the periphery of the metal base and the electrostatic chuck; The second quartz ring is located on the first quartz ring and is arranged around the periphery of the electrostatic chuck; The upper ceramic pressure ring is located on the second quartz ring.

3. The lower electrode assembly as described in claim 2, characterized in that, The upper surface of the electrostatic chuck is provided with a recessed electrostatic chuck step at the edge; The lower electrode assembly also includes an adjustment component, which is disposed on the electrostatic chuck step and surrounded by the first quartz ring and the second quartz ring; the outer periphery of the adjustment component has gaps between it and the inner wall of the first quartz ring and the inner wall of the second quartz ring.

4. The lower electrode assembly as described in claim 3, characterized in that, The top of the second quartz ring is provided with multiple continuous steps, which are distributed radially and gradually increase from the inside to the outside of the second quartz ring; The adjustment component includes: A base ring is disposed on the step of the electrostatic chuck and is surrounded by the first quartz ring and the second quartz ring; the upper surface of the base ring is flush with the step surface of the innermost step at the top of the second quartz ring; An edge ring, comprising the innermost step at the top of the base ring and the second quartz ring. The surface formed.

5. The lower electrode assembly as described in claim 4, characterized in that, The base ring is a metal base ring, and the surface of the metal base ring that contacts the electrostatic chuck step is provided with an anodic oxide film; gaps are left between the outer periphery of the base ring and the inner wall of the first quartz ring and the inner wall of the second quartz ring.

6. The lower electrode assembly as described in claim 4, characterized in that, The multi-level continuous steps also include a second level of steps connected to the innermost step. The upper surface of the edge ring is flush with the step surface of the second step at the top of the second quartz ring; The edge ring has a gap between the side of the second quartz ring and the side wall from the innermost step to the second step; the edge ring has a notch structure on the other side of the electrostatic chuck.

7. The lower electrode assembly as described in claim 2, characterized in that, The grounding component includes: The lower grounding ring is located on the outer region of the top of the lower electrode cavity wall and is arranged around the periphery of the lower ceramic ring and the first quartz ring; and the inner wall of the lower grounding ring has gaps with the periphery of the lower ceramic ring and the periphery of the first quartz ring. The inner liner has one end located between the lower grounding ring and the upper grounding ring, surrounding the periphery of the first quartz ring, and leaving a gap with the periphery of the first quartz ring; the other end of the inner liner extends radially outward and upward into the cavity. The upper grounding ring is arranged around the periphery of the first quartz ring; and the inner wall of the upper grounding ring has a gap with the periphery of the first quartz ring.

8. The lower electrode assembly as described in claim 2, characterized in that, The top of the upper ceramic pressure ring is provided with: An inclined surface is radially inclined from the outside to the inside of the upper ceramic pressure ring, with the outer edge of the inclined surface being higher than the inner edge of the inclined surface. The first upper ceramic pressure ring plane extends horizontally outward from the outer edge of the inclined surface to the outer side wall of the upper ceramic pressure ring; The second upper ceramic pressure ring plane extends inward from the inner edge of the inclined surface.

9. The lower electrode assembly as described in claim 6, characterized in that, The bottom of the upper ceramic pressure ring is provided with a first fitting and limiting structure; The first fitting limiting structure is fitted into the outermost step of the top of the second quartz ring.

10. The lower electrode assembly as claimed in claim 9, characterized in that, The first fitting and limiting structure at the bottom of the upper ceramic pressure ring is a concave ring, which fits into the convex ring formed by the outermost step at the top of the second quartz ring.

11. The lower electrode assembly as claimed in claim 2, characterized in that, The second quartz ring has a second fitting and limiting structure at its bottom, and the first quartz ring has a third fitting and limiting structure at its top; the bottom of the second quartz ring and the top of the first quartz ring are installed by the cooperation of the second fitting and limiting structure and the third fitting and limiting structure.

12. The lower electrode assembly as claimed in claim 11, characterized in that, The second quartz ring has a first raised step at the bottom of its inner side that protrudes relative to the bottom of its outer side, and the first quartz ring has a first sunken step at the top of its inner side that is recessed relative to the top of its outer side. The plane at the bottom outer side of the second quartz ring abuts against the plane at the top outer side of the first quartz ring, and the first protruding step at the bottom inner side of the second quartz ring is fitted into the first recessed step at the top inner side of the first quartz ring.

13. The lower electrode assembly as claimed in claim 2, characterized in that, The first quartz ring has a fourth fitting and limiting structure at its bottom, the lower ceramic ring has a fifth fitting and limiting structure at its top, and the edge of the lower surface of the metal base has a sixth fitting and limiting structure. The bottom of the first quartz ring, the lower surface of the metal base, and the top of the lower ceramic ring are installed by the cooperation of the fourth, sixth, and fifth fitting limiting structures.

14. The lower electrode assembly as claimed in claim 13, characterized in that, The inner bottom of the first quartz ring is provided with a second recessed step that is recessed relative to the outer bottom; the middle top of the lower ceramic ring is provided with a second raised step that is raised relative to the outer top; the inner top of the lower ceramic ring is provided with a third recessed step that is recessed relative to the middle top; and a recessed metal base step is provided at the edge of the lower surface of the metal base. The outer bottom plane of the first quartz ring abuts against the outer top plane of the lower ceramic ring. The second protruding step at the middle top of the lower ceramic ring is fitted into the second recessed step at the inner bottom of the first quartz ring and the metal base step. The outer edge of the lower surface of the metal base is fitted into the third recessed step at the inner top of the lower ceramic ring.

15. The lower electrode assembly as claimed in claim 2, characterized in that, The bottom of the lower ceramic ring is provided with a seventh fitting limiting structure, and the top of the lower electrode cavity wall is provided with an eighth fitting limiting structure; the bottom of the lower ceramic ring and the top of the lower electrode cavity wall are installed by the cooperation of the seventh fitting limiting structure and the eighth fitting limiting structure.

16. The lower electrode assembly as claimed in claim 15, characterized in that, The lower ceramic ring has a third raised step on its inner bottom that protrudes relative to its outer bottom. The inner top of the lower electrode cavity wall is provided with a fourth recessed step that is recessed relative to the outer top. The outer bottom plane of the lower ceramic ring abuts against the outer top plane of the lower electrode cavity wall, and the third protruding step of the inner bottom of the lower ceramic ring is fitted into the fourth recessed step of the inner top of the lower electrode cavity wall.

17. The lower electrode assembly as claimed in claim 10, characterized in that, The bottom of the upper ceramic pressure ring contacts the top of the second quartz ring to form a fitting gap, and the minimum cumulative distance from the inner wall of the second quartz ring along the fitting gap to the outer wall of the second quartz ring is greater than or equal to 20 mm.

18. The lower electrode assembly as claimed in claim 12, characterized in that, The bottom of the second quartz ring contacts the top of the first quartz ring to form a fitting gap, and the minimum cumulative distance from the inner wall of the first quartz ring along the fitting gap to the outer wall of the first quartz ring is greater than or equal to 20 mm.

19. The lower electrode assembly as claimed in claim 14, characterized in that, The bottom of the first quartz ring contacts the top of the lower ceramic ring to form a fitting gap, and the minimum cumulative distance from the inner wall of the lower ceramic ring along the fitting gap to the contact surface of the outer wall of the lower ceramic ring is greater than or equal to 20 mm.

20. The lower electrode assembly as claimed in claim 2, characterized in that, The radial distance between the inner edge of the upper ceramic pressure ring and the edge of the wafer is 1 to 1.5 mm.

21. The lower electrode assembly as claimed in claim 6, characterized in that, An O-ring is positioned on the electrostatic chuck at a point where it contacts the edge ring and the base ring; The top plane of the O-ring is lower than the bottom wall of the notch structure of the edge ring, and the bottom plane of the O-ring is lower than the upper surface of the base ring, so as to form a misaligned structure to protect the electrostatic chuck.

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