A method for manufacturing a multi-temperature-zone electrostatic chuck and a multi-temperature-zone electrostatic chuck

Abstract

The application relates to the technical field of electrostatic chucks, in particular to a manufacturing method of a multi-temperature-zone electrostatic chuck and the multi-temperature-zone electrostatic chuck. The method comprises the following steps: forming a plurality of inter-plate interconnection units on each to-be-processed single-layer plate to obtain to-be-integrated single-layer plates; aligning two to-be-integrated single-layer plates in the same integration pair through the inter-plate interconnection units to form an initial stacking plate; carrying out copper plating at the inter-plate interconnection units, carrying out hot melting and bonding on the initial stacking plate after the copper plating, and applying ultrasonic energy to an interface region where the inter-plate interconnection units are located after the hot melting and bonding to form a first integrated plate; stacking all the first integrated plates, and arranging the inter-plate interconnection units between adjacent first integrated plates in a staggered manner, and then carrying out hot melting and bonding to form a second integrated plate; and hot melting and bonding the second integrated plate on an aluminum substrate to complete electrical connection according to a preset wiring definition to obtain a target electrostatic chuck. The application can realize more temperature zones of the electrostatic chuck, and the temperature control precision of the electrostatic chuck is improved.

Description

Technical Field

[0001] This application relates to the technical field of electrostatic chucks, and more particularly to a method for manufacturing a multi-temperature zone electrostatic chuck and the multi-temperature zone electrostatic chuck itself. Background Technology

[0002] In semiconductor manufacturing processes, the ESC (Electrostatic Chuck) is a key component for wafer support and temperature control. Its temperature control accuracy directly affects the yield and stability of critical processes such as photolithography and etching. To achieve highly uniform temperature control of the wafer surface, the industry generally adopts a multi-temperature zone heating structure. By independently adjusting the heating power of each temperature zone, edge effects and process thermal disturbances are compensated, thereby meeting the requirements of advanced processes for extremely low tolerance to temperature fluctuations.

[0003] Currently, the mainstream international manufacturing process for multilayer integrated electrostatic chucks relies on ultrasonic welding technology, integrating heating elements, heat spreaders, shielding layers, and sensing layers layer by layer. This process is limited by the penetration depth of ultrasonic energy in the material and the interfacial bonding strength, typically achieving a maximum of eight layers for reliable integration. Regardless of whether the ultrasonic welding is applied to metal or polymer materials, the effective total weld thickness is capped at approximately 0.65 mm, with a limit not exceeding 1 mm. Specifically, this limitation stems from the stringent requirements of wafer processing on the surface flatness (typically ≤3 μm) and roughness (Ra≤0.25 μm) of the electrostatic chuck. When the number of integrated layers increases and the total thickness exceeds the stable range of the ultrasonic process, interlayer adhesion decreases, easily leading to interfacial delamination or deformation.

[0004] The realization of each temperature zone in an electrostatic chuck requires a fixed number of lead wires for support. The arrangement of the lead wires depends on the carrier layers in the multi-layer integrated structure. Each layer can carry a certain number of functional lead wires such as sensor lines and power lines. That is, the increase in the number of temperature zones will directly lead to a linear increase in the total number of lead wires required. The more layers there are, the more lead wires can be carried, thus supporting the division of more temperature zones.

[0005] Therefore, due to the physical limitations of ultrasonic welding processes, the number of integrated layers in multi-layer functional structures is strictly limited to eight layers, thus restricting the further expansion of the number of temperature zones. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, this application provides a method for manufacturing a multi-temperature zone electrostatic chuck and a multi-temperature zone electrostatic chuck, so as to realize more temperature zones in the electrostatic chuck and thus improve the temperature control accuracy of the electrostatic chuck.

[0007] The technical solution adopted by this application to solve its technical problem is:

[0008] In a first aspect, this application provides a method for manufacturing a multi-temperature zone electrostatic chuck, the method comprising:

[0009] Each single-layer board to be processed is processed separately, and several inter-board interconnection units distributed in a ring array are formed on each single-layer board to be processed, so as to obtain multiple single-layer boards to be integrated.

[0010] All the single-layer boards to be integrated are divided into multiple integration pairs, and two single-layer boards to be integrated within the same integration pair are aligned through the inter-board interconnection unit to form an initial stacked board.

[0011] Copper plating is performed on the interconnect units aligned in the initial stacked board. The initial stacked board after copper plating is then thermally bonded. Ultrasonic energy is applied to the interface area where the interconnect units are located after thermal bonding to form a first integrated board.

[0012] All the first integrated boards are stacked together, and the inter-board interconnection units between adjacent first integrated boards are staggered. The stacked first integrated boards are then heat-fused together to form a second integrated board.

[0013] The second integrated board is hot-melt bonded to the aluminum substrate, and electrical connections are completed according to the preset wiring definition to obtain the target electrostatic chuck.

[0014] Optionally, the inter-board interconnect unit includes a connecting through hole, an annular copper disk surrounding the connecting through hole, and an annular groove surrounding the annular copper disk.

[0015] Optionally, the diameter of the connecting through hole ranges from 2 to 2.5 mm.

[0016] Optionally, the diameter of the annular copper disk ranges from 12 to 15 mm, the width of the annular copper disk ranges from 1 to 1.5 mm, and the copper plating thickness of the hole wall of the annular copper disk is 25 micrometers.

[0017] Optionally, the groove depth of the annular groove ranges from 0.5 to 0.8 mm, and the annular width ranges from 0.35 to 0.5 mm.

[0018] Optionally, the steps of plating copper at the interconnect units aligned in the initial stacked board, thermally bonding the copper-plated initial stacked board, and applying ultrasonic energy to the interface area where the interconnect units are located after thermal bonding to form the first integrated board include:

[0019] Copper plating is performed in the connecting through holes and the annular grooves aligned in the initial stacked board;

[0020] The initial stacked boards after copper plating are thermally bonded, and ultrasonic energy is applied to the interface area at the connecting through holes to obtain the first integrated board.

[0021] Optionally, the hot melt bonding step includes:

[0022] Two components to be bonded are identified, and the two components are heat-fused together using a vacuum hydraulic chamber to achieve heat fusion bonding of the two components; the step of heat-fused bonding the two components using a vacuum hydraulic chamber includes:

[0023] Adjust the environment to a first vacuum level, and align the two parts to be bonded using positioning pins under the first vacuum level;

[0024] The two components to be bonded are heated to a first preset temperature using a non-contact thermal radiation method to form a primary composite.

[0025] Fluoropolymer foam sheets of varying thicknesses are placed on the top and bottom surfaces of the primary composite. The foam sheets are then fused under pressure in stages at a second preset temperature to activate the self-generated adhesive layer on the surface of the component to be bonded, thereby forming a secondary composite.

[0026] Remove all the fluororubber foam sheets, perform ultrasonic targeting on the secondary composite under a second vacuum, hot-press densify the secondary composite after targeting at a third preset temperature, and perform pneumatic adsorption and gradient cooling on the hot-pressed composite.

[0027] The process of pressurizing and hot-pressing densification is repeated until the preset cycle termination condition is met, thus achieving the hot-melt bonding.

[0028] Optionally, the step of completing the electrical connection according to the preset wiring definition includes:

[0029] The second integrated board is wired according to the preset wiring definition;

[0030] The leads of the second integrated board, which has completed the wiring connection, are led out through a multi-pin connector to complete the electrical connection; the multi-pin connector is a SAMTECQTH male connector.

[0031] Optionally, the single-layer board to be processed is any one of the following: a shielding layer, a connector layer, a temperature sensing layer, a heat-conducting layer, or a heating layer.

[0032] Secondly, this application provides a multi-temperature zone electrostatic chuck, which is manufactured using the above-described method for manufacturing a multi-temperature zone electrostatic chuck.

[0033] The working principle of this application is as follows: First, each single-layer board to be processed is processed to form a single-layer board to be integrated with a ring array of inter-board interconnection units; then, these single-layer boards are stacked in pairs through the inter-board interconnection units, copper plating is used to enhance connectivity, and thermal fusion bonding is used to ensure tight contact between layers. Then, ultrasonic energy is applied to the interface of the inter-board interconnection units for directional reinforcement to form a first integrated board; subsequently, multiple first integrated boards are stacked, so that the adjacent inter-board interconnection units are staggered and thermally fused to form a second integrated board; finally, the second integrated board is thermally fused to the aluminum substrate and the electrical connection is completed to obtain the target electrostatic chuck.

[0034] Based on the above working principle, the beneficial effects of this application are as follows: In the initial integration stage, copper interconnection and hot-melt bonding are performed only on the integrated pairs consisting of two single-layer boards. Due to the small total material thickness, the hot-melt process can fully activate the self-generated adhesive layer at the interface, achieving high adhesion bonding; simultaneously, directional ultrasonic energy is applied to the aligned inter-board interconnect unit area, mainly to remove interface gases and improve local density. This local treatment ensures that the integration quality of each pair of single-layer boards is stable and controllable.

[0035] In the second integration stage, multiple first integrated boards that have completed internal integration are stacked together. At this point, if all the interconnecting units between the boards are perfectly aligned vertically, a continuous abrupt change in thickness will occur in the through-hole area, making it difficult for the overall structure to meet the stringent requirements for the flatness of the electrostatic chuck surface. Therefore, by staggering the interconnecting units between adjacent first integrated boards, local stress concentration and deformation accumulation are avoided, thus ensuring the flatness of the final product.

[0036] Based on this collaborative design of step-by-step integration and staggered layout, this application avoids the bottleneck of ultrasonic welding process being unable to achieve more layers of reliable integration due to the limitations of penetration depth and interface strength. Furthermore, since the number of temperature zones directly depends on the total number of leads that can be laid out, and the lead carrying capacity depends on the number of integrated layers, breaking through the layer limit means that more independent control circuits can be accommodated, thereby supporting more refined multi-temperature zone division and achieving higher temperature control accuracy of the electrostatic chuck. Attached Figure Description

[0037] Figure 1 This is a flowchart illustrating the manufacturing method of the multi-temperature zone electrostatic chuck provided in the embodiments of this application;

[0038] Figure 2 This is a schematic diagram of the functional layers of the multi-temperature zone electrostatic chuck provided in the embodiments of this application;

[0039] Figure 3 This is a schematic diagram of the manufacturing process of the first integrated board involved in the manufacturing method of the multi-temperature zone electrostatic chuck provided in the embodiments of this application;

[0040] Figure 4This is a schematic diagram of the functional layer pin definition of the multi-temperature zone electrostatic chuck provided in the embodiments of this application;

[0041] Figure 5 This is a plan view of the multi-temperature zone electrostatic chuck provided in the embodiments of this application.

[0042] Figure label:

[0043] 1. Inductor wiring definition; 2. Heating element electrode wiring definition; 3. Temperature sensing and thermal control wiring definition; 101. Outer ring temperature zone; 201. Middle ring temperature zone; 301. Inner ring temperature zone. Detailed Implementation

[0044] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0045] The following will clearly and completely describe the concept, specific structure, and resulting technical effects of this application in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of this application. Obviously, the described embodiments are only a part of the embodiments of this application, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are all within the scope of protection of this application. Furthermore, all connections / linkages involved in the patent do not simply refer to direct contact between components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. The various technical features in this application can be combined interactively without contradicting each other.

[0046] In semiconductor manufacturing equipment, the electrostatic chuck, as a core component that carries the wafer and achieves high-precision temperature control, directly impacts process stability and yield. To improve temperature control accuracy, the industry commonly employs multi-zone independent heating structures. By subdividing the temperature zones and separately controlling the temperature of each zone, it compensates for uneven thermal fields, edge effects, and dynamic thermal disturbances during the process. The more temperature zones there are, the finer the temperature distribution and the stronger the temperature control capability, theoretically.

[0047] Currently, the mainstream manufacturing of multilayer integrated electrostatic chucks mainly relies on ultrasonic technology to integrate multiple single-layer boards layer by layer. However, due to limitations in the effective penetration depth of ultrasonic energy in the material and the strength of interfacial bonding, it is usually possible to reliably integrate a structure of no more than eight layers, and the overall weld thickness is generally no more than 0.65 mm, and in extreme cases, it is difficult to exceed 1 mm. This limitation stems from the extremely high requirements of semiconductor processes for the surface flatness (usually required to be ≤3μm) and roughness (Ra≤0.25μm) of electrostatic chucks. When the stack thickness and the number of layers increase, ultrasonic waves are unable to form a sufficiently strong bond at the deep interface, which can easily lead to interlayer debonding, warping, or deformation, thereby compromising surface accuracy.

[0048] The realization of multi-temperature zone functionality relies on a sufficient number of leads. Each temperature zone requires independent power and sensor lines, and these leads must be laid out in the functional layers of a multi-layer structure. Therefore, the expansion of the number of temperature zones directly depends on the upper limit of the number of layers that can be integrated. However, due to the limitations of physical mechanisms, existing ultrasonic welding processes cannot reliably stack more layers while ensuring surface accuracy. Specifically, each temperature zone typically requires two temperature sensor lines and two power drive lines, i.e., four leads. In practical applications, on the one hand, to meet the strict limits of European standards on stray magnetic fields (<30 nT), the sensing circuit must adopt a symmetrical layout with positive and negative electrodes to achieve magnetic field cancellation. This design is highly dependent on the geometric symmetry and flatness of the circuit. If the wiring density is too high, it will be difficult to maintain the integrity of the cancellation structure, leading to local magnetic field exceeding the limit.

[0049] On the other hand, in multilayer stacked structures, parasitic capacitances are formed between adjacent metal layers. Especially when a large number of sensing leads are arranged in a single layer, these parasitic capacitances will couple interference currents during signal changes, indirectly exciting electromagnetic fields and further degrading sensing accuracy. Therefore, due to electromagnetic compatibility and signal integrity constraints, each layer of sensing leads can reliably lead out a maximum of four sensing lines.

[0050] Therefore, the expansion of the number of temperature zones directly depends on the upper limit of the number of integrable layers. However, due to the limitations of the integration mechanism, existing ultrasonic welding processes cannot reliably stack more layers while ensuring accuracy, thus fundamentally restricting the further increase in the number of temperature zones and making it difficult to meet the needs of advanced processes for more refined thermal management.

[0051] To address the aforementioned technical deficiencies, refer to Figure 1 , Figure 1 This is a schematic flowchart illustrating the manufacturing method of the multi-temperature zone electrostatic chuck provided in this application embodiment. Figure 1 The document illustrates several key steps involved in the method for fabricating electrostatic chucks capable of supporting more temperature ranges by breaking through existing integration layer counts, as provided in the embodiments of this application. These steps are described in detail below:

[0052] In step S1, each single-layer board to be processed is processed separately, and several inter-board interconnection units distributed in a ring array are formed on each single-layer board to be processed, so as to obtain multiple single-layer boards to be integrated.

[0053] Among them, the single-layer board to be processed refers to a single-layer structural board with a specific function that has not yet undergone integrated processing; the ring array distribution refers to a distribution method in which the boards are arranged in a ring with a certain center point as the center; the single-layer board to be integrated refers to a single-layer board that can be further integrated after the inter-board interconnection unit processing is completed.

[0054] Specifically, each single-layer board to be processed is individually fabricated, and interconnection units distributed in a circular array are created on it. The processed single-layer board is the single-layer board to be integrated. The core of this step is to pre-define the structure for subsequent connections for each single-layer board, and ensure the accuracy of each unit through individual processing, laying the foundation for subsequent multi-layer board integration.

[0055] More specifically, the inter-board interconnect unit is a structural unit used to connect different single-layer boards, comprising three parts: a connecting through-hole, an annular copper disk, and an annular groove. In the embodiments of this application, the inter-board interconnect unit achieves precise alignment of adjacent single-layer boards through the connecting through-hole, the annular copper disk ensures the stability of interlayer electrical connections with its copper-plated structure, and the annular groove provides additional space for copper plating and expands the current path.

[0056] The dimensions of each component are designed based on electrical requirements and structural stability to ensure the reliability and conductivity of interlayer connections. Specifically, the diameter of the connecting through-hole is 2-2.5 mm, which can accommodate the positioning pins for alignment without compromising the structural strength of the single-layer board due to excessive hole diameter; the annular copper disk has a diameter of 12-15 mm, a ring width of 1-1.5 mm, and a copper plating thickness of 25 microns, providing sufficient conductive area and a low-resistance conduction path to avoid overheating problems caused by excessive current; the annular groove has a depth of 0.5-0.8 mm and a ring width of 0.35-0.5 mm to increase the copper plating contact area, expand the current path, thereby improving the current carrying capacity and ensuring the stability of interlayer electrical connections.

[0057] In one specific embodiment, suppose a single-layer board to be processed is taken for heating function, and the single-layer board to be processed is processed. First, a through hole (i.e., a connecting through hole) with a diameter of 2.2 mm is drilled; then, an exposed copper surface (i.e., annular copper disk) is made around the through hole, with a copper plating thickness of 25 micrometers on the hole wall, a copper surface diameter of 13 mm, and a width of 1.2 mm; then, an annular groove is made on the outside of the copper surface, with a groove height of 0.6 mm and a width of 0.4 mm. These structures are distributed in a ring array, with 12 units evenly distributed in each ring with the center of the single-layer board to be processed as the center, for a total of 3 rings. After processing is completed, the single-layer board to be processed is called the single-layer board to be integrated.

[0058] More specifically, the single-layer board to be processed is any one of the following: a shielding layer, a connector layer, a temperature sensing layer, a heat-conducting layer, or a heating layer.

[0059] The shielding layer is a single-layer structure used to shield electromagnetic interference and reduce the impact of external signals on internal functions; the connector layer (connector and shielding layer) is a single-layer board that integrates connector components and shielding functions, serving both signal transmission and interference shielding purposes; the temperature sensing layer (circuit layer) is a single-layer board with temperature sensing circuitry, which collects temperature signals through the circuitry to achieve detection functions; the thermally conductive layer is a single-layer structure with high thermal conductivity, responsible for heat transfer and uniform distribution; and the heating layer is a single-layer board with built-in heating elements, which converts electrical energy into heat energy to provide a temperature control heat source.

[0060] In step S2, all the single-layer boards to be integrated are divided into multiple integration pairs, and the two single-layer boards to be integrated within the same integration pair are aligned through the inter-board interconnection unit to form an initial stacked board.

[0061] Among them, an integration pair is a unit formed by combining two single-layer boards to be integrated; the initial stacked board is a plate-like structure formed by stacking two single-layer boards to be integrated within the same integration pair after aligning them through inter-board interconnection units.

[0062] Specifically, multiple single-layer boards with different functions are first divided into several integration pairs. For each pair, the two boards are precisely aligned using the structural features of the inter-board interconnect units (i.e., connecting vias), ensuring that corresponding positions on the two boards completely overlap, thus forming the initial stacked board structure. (Refer to...) Figure 2 , Figure 2 This is a schematic diagram of the functional layer division of the electrostatic chuck provided in the embodiment of this application. The required integrated functional layers include at least six layers, of which L1 is a shielding layer, L2 is a circuit layer (connector and shielding layer), L3 is a shielding layer, L4 is a circuit layer (temperature sensing wire), L5 is a heat-conducting layer, and L6 is a heating layer.

[0063] In this embodiment, it is assumed that there are 6 single-layer boards to be integrated, which are divided into 3 integration pairs (1-2, 3-4, 5-6); if there are 12 single-layer boards to be integrated, they are divided into 6 integration pairs (1-2, 3-4, 5-6, 7-8, 9-10, 11-12). Taking pair 1-2 as an example, the connecting through holes in the inter-board interconnection units of single-layer board 1 and single-layer board 2 are aligned, and precise alignment is achieved by passing positioning pins through the connecting through holes. After stacking, the initial stacked board 1-2 is formed.

[0064] In step S3, copper plating is performed on the interconnect units aligned in the initial stacked board, the copper-plated initial stacked board is thermally bonded, and ultrasonic energy is applied to the interface area where the interconnect units are located after thermal bonding to form the first integrated board.

[0065] The initial stacked board is a stacked structure formed by aligning two single-layer boards to be integrated through inter-board interconnection units; copper plating is a process of depositing a copper layer in the aligned area of ​​the inter-board interconnection units; ultrasonic energy is an energy form that uses high-frequency vibration to enhance the bonding force of materials; the first integrated board is an integrated board structure formed after copper plating, hot-melt bonding and ultrasonic treatment.

[0066] Specifically, in the initial stacked board, the interconnect units between the two single-layer boards are precisely aligned. First, copper plating is performed in the aligned area to provide a conductive connection foundation between the layers. Then, the copper-plated initial stacked board is thermally bonded, and the interlayer materials are melted and initially bonded by heating (e.g., 430-450 degrees Celsius). Afterward, ultrasonic energy is applied to the interface area where the interlayer interconnect units are located, and high-frequency vibration is used to eliminate interface pores and enhance interlayer adhesion, ultimately forming a structurally stable first integrated board.

[0067] More specifically, refer to Figure 3 , Figure 3 This is a schematic diagram of the manufacturing process of the first integrated board involved in the manufacturing method of the multi-temperature zone electrostatic chuck provided in this application embodiment. As can be seen, in this application embodiment, the steps of copper plating at the interconnect units aligned in the initial stacked board, hot-melt bonding of the copper-plated initial stacked board, and applying ultrasonic energy to the interface area where the interconnect units are located after hot-melt bonding to form the first integrated board include:

[0068] Step S31: Copper plating is performed in the aligned connecting through holes and the annular groove in the initial stacked board;

[0069] Step S32: The initial stacked board after copper plating is hot-melted and bonded, and ultrasonic energy is applied to the interface area at the connecting through hole to obtain the first integrated board.

[0070] Specifically, the connecting vias and annular grooves in the initial stacked board are pre-aligned. First, copper plating is performed within these aligned structures to form conductive pathways, ensuring the stability of the interlayer electrical connections. Next, the copper-plated initial stacked board is thermally bonded. Then, ultrasonic energy is applied to the interface area at the connecting vias, with directional energy input to eliminate residual gas at the interface and further reinforce the bonding interface, ultimately forming the first integrated board.

[0071] It is worth noting that, in this embodiment, hot melt bonding is used, which avoids the porosity problem of traditional 3M adhesive bonding by melting and fusing the materials, thus reducing the impact on heat insulation. In this embodiment, the hot melt bonding step includes:

[0072] Two components to be bonded are identified, and the two components are heat-fused together using a vacuum hydraulic chamber to achieve heat fusion bonding of the two components; the step of heat-fused bonding the two components using a vacuum hydraulic chamber includes:

[0073] The vacuum hydraulic chamber is a sealed hydraulic device that creates a vacuum environment for heat-melting bonding under vacuum conditions. The components to be bonded are those requiring heat-melting bonding, including two single-layer boards, two first integrated boards, a second integrated board, and an aluminum substrate, etc., selected according to the specific execution steps.

[0074] Furthermore, the environment is adjusted to a first vacuum level, and the two parts to be bonded are aligned using positioning pins under the first vacuum level;

[0075] The first vacuum degree is the vacuum environment parameter adjusted in the initial stage of hot melt bonding, which is usually in the range of 100-136 PA; the positioning pin alignment is to make the corresponding positions of the two parts to be bonded precisely coincide through positioning fixtures and positioning pins.

[0076] Furthermore, a non-contact thermal radiation method is used to heat the two components to be bonded at a first preset temperature to form a primary composite.

[0077] Among them, non-contact thermal radiation is a process that heats the parts to be bonded without direct contact with them, through thermal radiation; the first preset temperature is the temperature of the initial heating stage, usually 120 degrees; the primary composite is a preliminary bond formed after the two parts to be bonded are initially heated.

[0078] Furthermore, fluororubber foam sheets of varying thicknesses are placed on the top and bottom surfaces of the primary composite, and then fused under pressure in stages at a second preset temperature to activate the self-generated adhesive layer on the surface of the component to be bonded, thereby forming a secondary composite.

[0079] Among them, the fluororubber foam sheet is a fluororubber foam material with high temperature resistance, used for buffering and uniform pressure during the heating and bonding process; the second preset temperature is the temperature during staged pressure fusion, usually 430-450 degrees; the self-generated adhesive layer is an adhesive layer generated on the surface of the parts to be bonded (such as PI heating element) at high temperature, with a thickness of about 3-3.5 μm; the secondary composite is a further bond formed after staged pressure fusion.

[0080] Further, all the fluororubber foam sheets are removed, and the secondary composite is subjected to ultrasonic targeting treatment under a second vacuum. The secondary composite after targeting treatment is hot-pressed and densified at a third preset temperature. The hot-pressed composite is then subjected to pneumatic adsorption and gradient cooling.

[0081] The second vacuum level is the vacuum environment parameter during ultrasonic targeting, typically 100-120 Pa. Ultrasonic targeting uses ultrasonic energy to pulse the bonding interface, enhancing the bonding force. The third preset temperature is the temperature of the hot-press densification stage, typically 350 degrees Celsius. Hot-press densification is a process that uses heating and pressurization to make the bonding interface tighter. Pneumatic adsorption and gradient cooling are processes that use pneumatic suction cups to adsorb the parts to be bonded and then slowly cool them down using a gradient method.

[0082] Furthermore, the pressurization and hot-press densification processes are repeated until the preset cycle termination condition is reached, thus achieving the hot-melt bonding.

[0083] The cycle termination condition is a preset standard for stopping the cycle process, such as the number of bonding layers reaching the requirement or the bonding force meeting the index.

[0084] Specifically, the core of hot melt bonding is to achieve a firm integration of the components to be bonded through a controlled environment provided by a vacuum hydraulic chamber, combined with the synergistic effect of multiple steps. First, the components to be bonded (such as single-layer boards, integrated boards, or aluminum substrates) are identified and placed inside the vacuum hydraulic chamber.

[0085] The first step is to adjust the environment to the first vacuum level (100-136 PA) to reduce air interference, and at the same time, align the components with the positioning pins to ensure accurate positioning.

[0086] The second step uses non-contact thermal radiation, lowering the heating plate of the vacuum hydraulic chamber to a distance of 1-2 mm from the surface of the component to be bonded, and heating it at a first preset temperature (e.g., 120°C) to initially soften the interface of the component and form a primary composite.

[0087] The third step involves placing fluororubber foam sheets of varying thicknesses (e.g., 10mm for the bottom layer and 5-8mm for the top layer) on the top and bottom surfaces of the primary composite. The elasticity of these sheets is used to uniformly transmit pressure. The foam is then pressed and fused in stages at a second preset temperature (430-450℃). In the first stage, the foam is pressed and heated for 30 seconds, followed by a 1-minute buffer before entering the second stage. This process is repeated for 3 minutes to activate the self-generated adhesive layer on the surface of the parts to be bonded, thereby enhancing interfacial adhesion and forming a secondary composite.

[0088] The fourth step is to remove the fluororubber foam sheet, adjust to the second vacuum level (100-120 PA), and reinforce the interface again by directional energy input through ultrasonic target hitting and remove residual gas.

[0089] Then, densification is achieved by hot pressing at a third preset temperature (e.g., 350°C) for about 30 minutes to improve structural flatness and interlayer adhesion. The components are then fixed by pneumatic adsorption, and the temperature is gradually reduced for about 45 minutes to reduce thermal stress. Finally, the pressurization and hot pressing densification processes are repeated until the preset interlayer adhesion and flatness requirements (e.g., flatness ≤ 3μm) are met, thus completing the hot melt bonding.

[0090] Compared to the currently predominantly used 3M adhesive bonding method, electrostatic chucks, when used in wafer processing, require flatness control within 3μm and roughness to reach Ra0.25μm. However, 3M adhesive bonding surfaces are prone to having a large number of pores. Air, as a heat insulation medium, not only affects the accuracy of temperature transmission but also leads to a decrease in the adhesion of the bonding interface. At the same time, during multilayer integration, the thickness error of each 3M adhesive layer and the unevenness of the interface will accumulate and be amplified, further reducing the overall flatness. This is a fatal flaw for multilayer integration that requires precise interlayer alignment and may even affect the magnetic field cancellation effect and sensing accuracy.

[0091] In contrast, hot melt bonding eliminates interfacial bubbles in a vacuum environment, then reinforces the interface and removes residual gas through a combination of ultrasonic targeting and hot pressing densification to ensure flatness. Finally, the hot melt bonding process is repeated to ensure that the interlayer adhesion and flatness meet the standards, supporting the integration of more layers and providing the possibility of expanding the number of temperature zones.

[0092] In step S4, all the first integrated boards are stacked, and the inter-board interconnection units between adjacent first integrated boards are staggered. The stacked first integrated boards are then heat-fused together to form a second integrated board.

[0093] The first integrated board is an integrated structure formed by copper plating and hot-melt bonding of multiple single-layer boards; the staggered arrangement refers to the arrangement in which the interconnection units between adjacent first integrated boards do not overlap; the second integrated board is a higher-level integrated structure formed by stacking and hot-melt bonding multiple first integrated boards, and the two adjacent first integrated boards are electrically connected by a pre-set isolation membrane on the board.

[0094] Specifically, multiple first integrated boards are stacked to ensure that the interconnection units between adjacent first integrated boards are staggered to avoid overlapping. Next, the stacked first integrated boards undergo high-temperature heat-melt bonding, with each pair of first integrated boards treated as a group to be bonded, according to... Figure 2 The layered arrangement shown above is subjected to the above-mentioned hot melt bonding process to form a second integrated board.

[0095] More specifically, the staggered arrangement of inter-board interconnect units avoids continuous thickness abrupt changes caused by the alignment of through holes, effectively ensuring the flatness of the overall structure; high-temperature hot-melt bonding combined with vacuum environment and ultrasonic treatment enhances interlayer adhesion, supports the integration of more layers, thus enabling it to carry more leads, providing a basis for realizing more temperature zone divisions, and improving the temperature control accuracy of the electrostatic chuck.

[0096] In step S5, the second integrated board is thermally bonded to the aluminum substrate, and electrical connections are completed according to the preset wiring definition to obtain the target electrostatic chuck.

[0097] The second integrated board is a multi-layer integrated structure formed by stacking and hot-melting multiple first integrated boards; the aluminum substrate is an aluminum alloy sheet that serves as the bearing base, i.e., an electric heating element; and the target electrostatic chuck is the final electrostatic chuck product with multi-temperature zone temperature control function.

[0098] Specifically, the second integrated board is aligned with the aluminum substrate, and these two are used as the components to be bonded. A high-temperature hot-melt bonding process is used to tightly bond them together. Then, according to the preset wiring definition, the functional leads in the second integrated board are connected to the corresponding interfaces on the aluminum substrate, and the circuitry is led out through a SAMTECQTH male connector, ultimately forming the target electrostatic chuck. The SAMTECQTH male connector supports the centralized output of a large number of leads, providing a wiring foundation for multi-temperature zone designs. (Refer to...) Figure 4 , Figure 4 This is a schematic diagram of the functional layer pin definitions of the multi-temperature zone electrostatic chuck provided in this application embodiment. The diagram shows the inductor wiring definition 1, the heating element electrode wiring definition 2, and the temperature sensing and thermal control wiring definition 3, corresponding to the pin requirements of each functional module of the multi-temperature zone electrostatic chuck. The temperature sensing and thermal control includes NTC, shielding, and temperature equalization functions. The SAMTECQTH male connector, as a multi-pin connector, serves to centrally lead out these leads scattered across the functional layers of the second integrated board according to the preset wiring definitions, completing the electrical connection of the entire electrostatic chuck. This centralized wiring method supports the stable transmission of a large number of leads, providing a circuit foundation for multi-temperature zone design, ensuring reliable transmission of signals and power from each functional module, thereby supporting the temperature control accuracy and functional realization of the multi-temperature zone electrostatic chuck.

[0099] Secondly, this application provides a multi-temperature zone electrostatic chuck, manufactured using the aforementioned method for manufacturing a multi-temperature zone electrostatic chuck. (Refer to...) Figure 5 , Figure 5This is a planar schematic diagram of the multi-temperature zone electrostatic chuck provided in this application embodiment. It can be seen that the finished electrostatic chuck is divided into an outer ring temperature zone 101, a middle ring temperature zone 201, and an inner ring temperature zone 301 from the outside in. The outer ring temperature zone 101 is an example of all the outer ring temperature zones, the middle ring temperature zone 201 is an example of all the middle ring temperature zones, and the inner ring temperature zone 301 is an example of all the inner ring temperature zones. That is, using a concentric circle layered structure, it is divided into annular areas composed of multiple trapezoidal units from the outside in. Each independent trapezoidal unit corresponds to a temperature zone that can be individually adjusted. This refined layout achieves precise control of up to 130 temperature zones.

[0100] The above is a detailed description of the preferred embodiments of this application. However, the invention of this application is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A method for manufacturing a multi-temperature zone electrostatic chuck, characterized in that, The method includes: Each single-layer board to be processed is processed separately, and several inter-board interconnection units distributed in a ring array are formed on each single-layer board to be processed, so as to obtain multiple single-layer boards to be integrated. All the single-layer boards to be integrated are divided into multiple integration pairs, and two single-layer boards to be integrated within the same integration pair are aligned through the inter-board interconnection unit to form an initial stacked board. Copper plating is performed on the interconnect units aligned in the initial stacked board. The initial stacked board after copper plating is then thermally bonded. Ultrasonic energy is applied to the interface area where the interconnect units are located after thermal bonding to form a first integrated board. All the first integrated boards are stacked together, and the inter-board interconnection units between adjacent first integrated boards are staggered. The stacked first integrated boards are then heat-fused together to form a second integrated board. The second integrated board is hot-melt bonded to the aluminum substrate, and electrical connections are completed according to the preset wiring definition to obtain the target electrostatic chuck.

2. The method for manufacturing a multi-temperature zone electrostatic chuck according to claim 1, characterized in that, The inter-board interconnect unit includes a connecting through hole, an annular copper disk surrounding the connecting through hole, and an annular groove surrounding the annular copper disk.

3. The method for manufacturing a multi-temperature zone electrostatic chuck according to claim 2, characterized in that, The diameter of the connecting through hole ranges from 2 to 2.5 mm.

4. The method for manufacturing a multi-temperature zone electrostatic chuck according to claim 2, characterized in that, The diameter of the annular copper disk ranges from 12 to 15 mm, the width of the annular copper disk ranges from 1 to 1.5 mm, and the copper plating thickness of the hole wall of the annular copper disk is 25 micrometers.

5. The method for manufacturing a multi-temperature zone electrostatic chuck according to claim 2, characterized in that, The groove depth of the annular groove ranges from 0.5 to 0.8 mm, and the annular groove width ranges from 0.35 to 0.5 mm.

6. The method for manufacturing a multi-temperature zone electrostatic chuck according to claim 2, characterized in that, The steps of plating copper at the interconnect units aligned in the initial stacked board, thermally bonding the copper-plated initial stacked board, and applying ultrasonic energy to the interface area where the interconnect units are located after thermal bonding to form the first integrated board include: Copper plating is performed in the connecting through holes and the annular grooves aligned in the initial stacked board; The initial stacked boards after copper plating are thermally bonded, and ultrasonic energy is applied to the interface area at the connecting through holes to obtain the first integrated board.

7. The method for manufacturing a multi-temperature zone electrostatic chuck according to claim 1, characterized in that, The hot melt bonding step includes: Two components to be bonded are identified, and the two components are heat-fused together using a vacuum hydraulic chamber to achieve heat fusion bonding of the two components; the step of heat-fused bonding the two components using a vacuum hydraulic chamber includes: Adjust the environment to a first vacuum level, and align the two parts to be bonded using positioning pins under the first vacuum level; The two components to be bonded are heated to a first preset temperature using a non-contact thermal radiation method to form a primary composite. Fluoropolymer foam sheets of varying thicknesses are placed on the top and bottom surfaces of the primary composite. The foam sheets are then fused under pressure in stages at a second preset temperature to activate the self-generated adhesive layer on the surface of the component to be bonded, thereby forming a secondary composite. Remove all the fluororubber foam sheets, perform ultrasonic targeting on the secondary composite under a second vacuum, hot-press densify the secondary composite after targeting at a third preset temperature, and perform pneumatic adsorption and gradient cooling on the hot-pressed composite. The process of pressurizing and hot-pressing densification is repeated until the preset cycle termination condition is met, thus achieving the hot-melt bonding.

8. The method for manufacturing a multi-temperature zone electrostatic chuck according to claim 1, characterized in that, The steps for completing the electrical connection according to the preset wiring definition include: The second integrated board is wired according to the preset wiring definition; The leads of the second integrated board, which has completed the wiring connection, are led out through a multi-pin connector to complete the electrical connection; the multi-pin connector is a SAMTECQTH male connector.

9. The method for manufacturing a multi-temperature zone electrostatic chuck according to claim 1, characterized in that, The single-layer board to be processed is any one of the following: shielding layer, connector layer, temperature sensing layer, heat-conducting layer, or heating layer.

10. A multi-temperature zone electrostatic chuck, characterized in that, It is manufactured using the manufacturing method of the multi-temperature zone electrostatic chuck as described in any one of claims 1-9.

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