Shielding protection system for electron beam inspection apparatus

Abstract

This invention provides a shielding protection system for an electron beam detection device. The shielding protection system includes: an external shielding structure, disposed inside the door panel of the electron beam detection device, employing a multi-layer composite structure to achieve a balance between lightweight design and electromagnetic shielding; an internal shielding structure, disposed on the inner wall of the process cavity of the electron beam detection device, further reducing external electromagnetic interference through specific metal materials and matching processes; a vibration isolation structure, disposed at the connection between the process cavity and the main body of the electron beam detection device, configured to dampen vibration to ensure electron beam focusing accuracy; and a monitoring and control module configured to monitor the electromagnetic environment data inside the electron beam detection device and execute interference suppression strategies based on the monitoring results. This invention's system, through multi-layer composite shielding and active vibration isolation structures, enhances electromagnetic and vibration interference protection capabilities, achieving a balance between lightweight design and electromagnetic shielding.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a shielding protection system for an electron beam detection device. Background Technology

[0002] Electron beam inspection equipment is a key device in semiconductor manufacturing for detecting nanoscale critical dimensions and defects in chips. Its inspection process relies on a stable inspection environment. However, electron beams are highly sensitive, and external interference factors such as electromagnetic and electric field fluctuations and vibrations can easily cause electron beam trajectory deviation, resulting in distorted detection signals and thus reducing the accuracy of critical dimension measurement and defect identification.

[0003] The conventional shielding protection method in the existing technology is to use special metal shielding materials to construct the main shielding cover of the equipment, and to add shielding structures to some special areas of the equipment for local shielding reinforcement. In addition, the equipment shell is grounded and metal shielding mesh is wrapped around the cables to reduce the interference of external electromagnetic waves on the electron beam trajectory.

[0004] However, the existing shielding protection methods have the following technical problems: the contradiction between shielding effectiveness and equipment integration is prominent. To achieve sufficient electromagnetic shielding effect, traditional metal shielding structures need to increase material thickness, resulting in a large equipment size and a surge in weight; electromagnetic interference protection is not targeted enough, as electromagnetic interference generated by a large number of complex devices in the application site (Fabrication Plant, or FAB) can easily penetrate traditional metal shielding systems; there is a lack of dynamic monitoring and adaptive adjustment capabilities, as different FABs have different main causes of electromagnetic vibration and other interference, making it impossible to dynamically adjust the shielding level according to the interference situation; there is a lack of protection against vibration interference, as traditional metal shielding structures are rigid and easily transmit external vibrations to the detection chamber, affecting detection accuracy; and it is difficult to balance ease of maintenance with airtightness. Summary of the Invention

[0005] One objective of this invention is to address the shortcomings of traditional electron beam detection equipment shielding systems, such as bulkiness, insufficient shielding targeting, lack of dynamic adjustment, and poor vibration resistance, thereby improving electromagnetic and vibration interference protection capabilities.

[0006] A further objective of this invention is to achieve lightweight design, high shielding effectiveness, real-time monitoring, and intelligent adaptive control, ensuring nanometer-level detection accuracy and equipment stability.

[0007] Specifically, this invention provides a shielding protection system for an electron beam detection device, comprising: an external shielding structure disposed on the inner side of the door panel of the electron beam detection device, employing a multi-layer composite structure to achieve a balance between lightweighting and electromagnetic shielding; an internal shielding structure disposed on the inner wall of the process cavity of the electron beam detection device, further reducing external electromagnetic interference through specific metal materials and matching processes; a vibration isolation structure disposed at the connection between the process cavity and the main body of the electron beam detection device, configured to dampen vibration to ensure electron beam focusing accuracy; and a monitoring and control module configured to monitor the electromagnetic environment data inside the electron beam detection device and execute interference suppression strategies based on the monitoring results.

[0008] Optionally, the monitoring and control module includes: a monitoring probe, set at a preset key position on the inner wall of the electron beam detection device, configured to collect electromagnetic environment data; and a controller, configured to execute an interference suppression strategy when the electromagnetic environment data determines that the high-frequency electromagnetic interference exceeds the standard.

[0009] Optionally, the monitoring and control module also includes: an active electromagnetic interference cancellation device, which is arranged in a ring array in the ring space between the outside of the process cavity and the multi-layer composite structure. The interference suppression strategy includes activating the active electromagnetic interference cancellation device to emit a reverse phase electromagnetic signal.

[0010] Optionally, the controller adopts an architecture that combines a programmable logic controller with an embedded system, and incorporates a safety threshold algorithm and interference suppression strategy.

[0011] Optionally, the monitoring and control module also includes: a human-machine interface configured to display monitoring data and equipment operating status in real time, and to support remote data transmission and fault diagnosis.

[0012] Optionally, the multi-layer composite structure includes, from the inside out: a functional ceramic layer, a lightweight alloy layer, and an electromagnetic shielding film, and the above three layers are fixed by a high-temperature vacuum pressure integrated composite bonding process.

[0013] Optionally, the functional ceramic layer is a lead tungstate ceramic layer; the lightweight alloy layer is a magnesium-aluminum alloy honeycomb structure layer, and the honeycomb pores of the magnesium-aluminum alloy honeycomb structure are filled with nano-absorbing materials; the electromagnetic shielding film is a flexible copper foil shielding film.

[0014] Optionally, the nano-absorbing material is a carbon nanotube / ferrite composite material; the flexible copper foil shielding film enhances the shielding effect against low-frequency electromagnetic interference through grounding design.

[0015] Optionally, the specific metallic material in the cavity shielding structure is permalloy; the supporting processes include: demagnetization process, grounding process, and matching process with the cavity material.

[0016] Optionally, the vibration isolation structure is an active vibration isolator, which is equipped with an acceleration sensor to monitor vibration signals in real time, and the active vibration isolator is configured to dynamically adjust the damping coefficient according to the vibration signal to achieve vibration attenuation.

[0017] The shielding protection system of the electron beam detection equipment of the present invention, through the combination of a multi-layer composite shielding structure and a permalloy inner layer shielding, significantly improves the electromagnetic shielding effectiveness and X-ray attenuation capability. While achieving lightweight and miniaturized equipment, it can effectively block broadband electromagnetic interference in complex application environments, providing a stable electromagnetic environment for electron beam detection. The active vibration isolation structure can significantly attenuate the transmission of external vibrations, avoid electron beam deviation, and ensure nanometer-level detection accuracy.

[0018] Furthermore, the shielding protection system of the electron beam detection equipment of the present invention, relying on the real-time monitoring and intelligent control module, can adaptively activate the interference cancellation strategy according to the on-site interference status, thereby achieving dynamic optimization of shielding protection. The overall solution takes into account high shielding performance, lightweight structure, good sealing performance and convenient maintenance, and can adapt to the complex working conditions of different application sites, significantly improving the operational stability and detection reliability of the electron beam detection equipment.

[0019] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0020] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the shielding and protection system of an electron beam detection device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the external shielding structure of the shielding protection system of an electron beam detection device according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the cavity shielding structure of the shielding protection system of an electron beam detection device according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the vibration isolation structure of the shielding protection system of an electron beam detection device according to an embodiment of the present invention; and Figure 5 This is a schematic diagram of the monitoring and control module of the shielding protection system of an electron beam detection device according to an embodiment of the present invention. Detailed Implementation

[0021] This embodiment provides a shielding protection system for an electron beam detection device. Through multi-layer composite shielding and active vibration isolation structure, it significantly improves the protection capability against electromagnetic and vibration interference, achieving a balance between lightweight and high shielding effectiveness. Relying on real-time intelligent control to achieve dynamic interference suppression, it can be adapted to different application sites, significantly improving the stability and detection accuracy of the electron beam detection device. Figure 1 This is a schematic diagram of the overall structure of the shielding protection system 100 of an electron beam detection device according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the external shielding structure 110 of the shielding protection system 100 of an electron beam detection device according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the intracavity shielding structure 120 of the shielding protection system 100 of an electron beam detection device according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the vibration isolation structure 130 of the shielding protection system 100 of an electron beam detection device according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the monitoring and control module of the shielding protection system 100 of an electron beam detection device according to an embodiment of the present invention. Figures 1 to 5 As shown, the shielding protection system 100 of the electron beam detection equipment in this embodiment generally includes: an external shielding structure 110, an internal shielding structure 120, a vibration isolation structure 130, and a monitoring and control module.

[0022] The external shielding structure 110 is located inside the door panel 102 of the electron beam detection equipment, and employs a multi-layer composite structure to achieve a balance between lightweight design and electromagnetic shielding. Figure 2 As shown, in one specific embodiment, the multi-layer composite structure includes, from the inside out: a functional ceramic layer 111, a lightweight alloy layer 112, and an electromagnetic shielding film 113. The "from the inside out" refers to the area relative to the door panel 102; that is, the functional ceramic layer 111 is in close contact with the door panel 102, the middle layer is the lightweight alloy layer 112, and the outermost visible layer is the electromagnetic shielding film 113.

[0023] In a preferred embodiment, the functional ceramic layer 111 is a lead tungstate ceramic layer, which has an X-ray attenuation coefficient that is about 30% higher than that of traditional lead materials, and a density reduction of about 25%, achieving a balance between lightweight and efficient electromagnetic shielding. The lightweight alloy layer 112 is a magnesium-aluminum alloy honeycomb structure layer, which further reduces weight while ensuring structural strength. Furthermore, the honeycomb cells of the magnesium-aluminum alloy honeycomb structure are filled with nano-absorbing material. The electromagnetic shielding film 113 is a flexible copper foil shielding film. More preferably, the nano-absorbing material is a carbon nanotube / ferrite composite material, which can suppress high-frequency electromagnetic interference of 1-10GHz by more than 45dB. The flexible copper foil shielding film enhances the shielding effect against low-frequency electromagnetic interference through a grounding design. Specifically, Figure 2 Grounding is achieved through the first grounding terminal 114.

[0024] Furthermore, the three-layer structure of the functional ceramic layer 111, the lightweight alloy layer 112, and the electromagnetic shielding film 113 can be fixed by a high-temperature vacuum pressure integrated composite bonding process. This allows the three-layer structure to be permanently composited in a bubble-free, gap-free, high-bonding-strength, and low-stress state, solving the interfacial bonding problem of three heterogeneous materials: ceramic, honeycomb metal, and flexible film, and ensuring shielding effectiveness, structural strength, and long-term reliability.

[0025] In summary, the external shielding structure 110 inside the door panel 102 adopts a sandwich composite structure of "functional ceramic layer 111-lightweight alloy layer 112-electromagnetic shielding film 113" to replace the traditional single metal shield. The overall thickness of the three-layer structure is reduced by about 40% and the weight is reduced by about 50% compared with the traditional metal shield, effectively achieving a balance between lightweighting and electromagnetic shielding.

[0026] An internal shielding structure 120 is disposed on the inner wall of the process cavity 101 of the electron beam detection equipment. Through the use of a specific metallic material and in conjunction with supporting processes, it further reduces external electromagnetic interference. In one specific embodiment, the specific metallic material in the internal shielding structure 120 is permalloy. The permalloy can be bonded to six surfaces of the inner wall of the process cavity 101: the top surface, the bottom surface, and the four peripheral surfaces. Supporting processes include demagnetization, grounding, and compatibility with the cavity material. This further and more effectively reduces external electromagnetic interference during electron beam detection, achieving a magnetic field suppression rate of up to 99.9%.

[0027] In a preferred embodiment, the inner wall of the process cavity 101 can be made of high-permeability superpermalloy as the inner magnetic shielding layer. Through key processes such as material demagnetization treatment, precision bonding and installation, multi-point low-resistance grounding, cavity material matching, and magnetic continuity of joints, a fully enclosed, low-leakage, and highly stable magnetic shielding cavity is formed, isolating external stray magnetic fields, power frequency magnetic fields, and equipment electromagnetic interference outside the electron beam working area. Specifically, Figure 3 Grounding is achieved through the second grounding terminal 121.

[0028] A vibration isolation structure 130 is disposed at the connection between the process cavity 101 and the main body of the electron beam detection equipment, configured to dampen vibration to ensure the focusing accuracy of the electron beam. In a specific embodiment, the vibration isolation structure 130 is an active vibration isolator, which is equipped with an acceleration sensor to monitor vibration signals in real time, and the active vibration isolator is configured to dynamically adjust the damping coefficient according to the vibration signal to achieve vibration attenuation. In a specific embodiment, by dynamically adjusting the damping coefficient, the vibration attenuation rate in the 5-500Hz frequency band can reach more than 95%, ensuring the focusing accuracy of the electron beam.

[0029] The monitoring and control module is configured to monitor the electromagnetic environment data inside the electron beam detection equipment and execute interference suppression strategies based on the monitoring results. In one specific embodiment, the monitoring and control module may include a monitoring probe and a controller. The monitoring probe is positioned at a preset key location on the inner wall of the electron beam detection equipment and is configured to collect electromagnetic environment data. The electromagnetic environment data can be transmitted to the controller. The controller is configured to execute interference suppression strategies when it determines that high-frequency electromagnetic interference exceeds the limit based on the electromagnetic environment data.

[0030] Furthermore, the monitoring and control module may also include an active electromagnetic interference cancellation device 140. The active electromagnetic interference cancellation device 140 can be arranged in a ring array within the annular space between the outside of the process cavity 101 and the multi-layer composite structure. This creates a 360° fully enclosed interference cancellation area around the process cavity 101. The interference suppression strategy includes activating the active electromagnetic interference cancellation device 140 to emit a reverse-phase electromagnetic signal. By emitting a reverse-phase electromagnetic signal to cancel external interference, the electron beam trajectory offset can be kept within 0.01 μm.

[0031] In one specific embodiment, the controller adopts an architecture combining a Programmable Logic Controller (PLC) and an embedded system, with built-in safety threshold algorithms and interference suppression strategies. Specifically, the safety threshold algorithm refers to the method mentioned above for determining whether high-frequency electromagnetic interference exceeds the limit based on electromagnetic environment data. The monitoring and control module may also include a human-machine interface. The human-machine interface can be configured to display monitoring data and equipment operating status in real time, and supports remote data transmission and fault diagnosis.

[0032] In a preferred embodiment, the monitoring probe can be a multi-channel electromagnetic interference monitoring probe. Furthermore, the preset key locations on the inner wall of the electron beam detection equipment may include: the periphery of the electron gun and electron optical system, the sealing joint of the door panel 102, the cable penetration interface, the observation window, and the flange connection. Each monitoring probe can be evenly distributed in three-dimensional space to collect full-band electromagnetic interference data in real time, providing the controller with accurate field strength information to drive the active electromagnetic interference cancellation device 140 to achieve dynamic adaptive suppression.

[0033] The shielding protection system 100 of the electron beam detection equipment in this embodiment, through the deep integration of material innovation, structural optimization, and intelligent control, can effectively resist complex electromagnetic environments and vibration interference, while also achieving lightweight, modularity, and maintainability, thus solving the core pain points of traditional solutions. As semiconductor electron beam detection equipment makes breakthroughs towards 3nm and below process technologies, this shielding protection system 100 can achieve performance iterations by upgrading sensor accuracy and algorithm models, possessing excellent technical scalability and application prospects.

[0034] It should be emphasized that the shielding protection system 100 of the electron beam detection equipment in this embodiment, through the combination of a multi-layer composite shielding structure and a permalloy inner layer shielding, significantly improves the electromagnetic shielding effectiveness and X-ray attenuation capability. While achieving lightweight and miniaturized equipment, it can effectively block broadband electromagnetic interference in complex application environments, providing a stable electromagnetic environment for electron beam detection. The active vibration isolation structure 130 can significantly attenuate the transmission of external vibrations, prevent electron beam deflection, and ensure nanometer-level detection accuracy.

[0035] Furthermore, the shielding protection system 100 of the electron beam detection equipment in this embodiment, relying on the real-time monitoring and intelligent control module, can adaptively activate the interference cancellation strategy according to the on-site interference status, thereby achieving dynamic optimization of shielding protection. The overall solution takes into account high shielding performance, lightweight structure, good sealing performance and convenient maintenance, and can adapt to the complex working conditions of different application sites, significantly improving the operational stability and detection reliability of the electron beam detection equipment.

[0036] Those skilled in the art should understand that, unless otherwise specified, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," "clockwise," and "counterclockwise" used to indicate orientation or positional relationships in the embodiments of the present invention are merely for the convenience of describing and understanding the technical solutions of the present invention, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0037] The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," etc., may explicitly or implicitly include at least one of that feature, that is, include one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. When a feature "includes or contains" one or more of the features it encompasses, unless otherwise specifically stated, this indicates that other features are not excluded and may be further included.

[0038] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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, unless otherwise expressly limited. Those skilled in the art should be able to understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0039] Furthermore, in the description of this embodiment, "above" or "below" the second feature can include direct contact between the first and second features, or it can include contact between the first and second features through another feature between them. That is, in the description of this embodiment, "above," "over," and "on top" of the second feature includes the first feature being 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," or "below" of the second feature can mean the first feature is 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.

[0040] In the description of this embodiment, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0041] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A shielding protection system for an electron beam detection device, comprising: An external shielding structure is installed inside the door panel of the electron beam detection device, and adopts a multi-layer composite structure to achieve a balance between lightweight and electromagnetic shielding; An internal shielding structure is installed on the inner wall of the process cavity of the electron beam detection equipment. Through the use of specific metal materials and matching processes, it further reduces external electromagnetic interference. A vibration isolation structure is provided at the connection between the process cavity and the main body of the electron beam detection equipment, and is configured to dampen vibration to ensure the electron beam focusing accuracy. as well as The monitoring and control module is configured to monitor the electromagnetic environment data inside the electron beam detection device and execute interference suppression strategies based on the monitoring results.

2. The system according to claim 1, wherein the monitoring and control module comprises: A monitoring probe is installed at a predetermined key position on the inner wall of the electron beam detection device and configured to collect electromagnetic environment data. as well as The controller is configured to execute the interference suppression strategy when it is determined, based on the electromagnetic environment data, that the high-frequency electromagnetic interference exceeds the limit.

3. The system according to claim 2, wherein the monitoring and control module further comprises: An active electromagnetic interference cancellation device is arranged in a ring array within the ring space between the outside of the process cavity and the multilayer composite structure. The interference suppression strategy includes activating the active electromagnetic interference cancellation device to emit a reverse-phase electromagnetic signal.

4. The system according to claim 2, wherein, The controller adopts an architecture that combines a programmable logic controller and an embedded system, and has a built-in safety threshold algorithm and the interference suppression strategy.

5. The system according to claim 1, wherein the monitoring and control module further comprises: The human-machine interface is configured to display monitoring data and equipment operating status in real time, and supports remote data transmission and fault diagnosis.

6. The system according to claim 1, wherein, The multi-layer composite structure comprises, from the inside out, a functional ceramic layer, a lightweight alloy layer, and an electromagnetic shielding film, and the above three layers are fixed by a high-temperature vacuum pressure integrated composite bonding process.

7. The system according to claim 6, wherein, The functional ceramic layer is a lead tungstate ceramic layer; The lightweight alloy layer is a magnesium-aluminum alloy honeycomb structure layer, and the honeycomb pores of the magnesium-aluminum alloy honeycomb structure are filled with nano-absorbing materials. The electromagnetic shielding film is a flexible copper foil shielding film.

8. The system according to claim 7, wherein, The nano-absorbing material is a carbon nanotube / ferrite composite material; The flexible copper foil shielding film enhances its shielding effect against low-frequency electromagnetic interference through a grounding design.

9. The system according to claim 1, wherein, The specific metallic material in the cavity shielding structure is permalloy; The supporting processes include: demagnetization process, grounding process, and matching process with the materials of the process cavity.

10. The system according to claim 1, wherein, The vibration isolation structure is an active vibration isolator, which is equipped with an acceleration sensor to monitor vibration signals in real time. The active vibration isolator is also configured to dynamically adjust the damping coefficient according to the vibration signals to achieve vibration attenuation.

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