Electrostatic chuck and semiconductor processing machine table
The electrostatic chuck with a cross-shaped electrode design solves the problems of scratches on the back of the wafer and poor heat dissipation, achieving a higher semiconductor packaging yield.
Patent Information
- Application Number
- CN202423094453.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-13
- Publication Date
- 2026-02-06
- Estimated Expiration
- 2034-12-13
AI Technical Summary
Existing electrostatic chuck designs result in scratches on the back of the wafer and poor heat dissipation, affecting semiconductor packaging yield.
The electrodes of the electrostatic chuck are designed in a cross shape, and the substrate is divided into multiple unit bearing areas. Each area is an individual force-bearing unit. The preset shape intervals and through holes form airflow channels, providing flow paths to enhance heat dissipation.
This avoids scratches on the back of the wafer, improves heat dissipation, and increases the yield of semiconductor packaging.
Smart Images
Figure CN223885619U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of semiconductor preparation process, especially relates to a static chuck and semiconductor processing machine platform. BACKGROUND
[0002] Electrostatic Chuck (ESC) is a kind of clamping tool using electrostatic adsorption principle to fix wafer, avoid to exert physical force to wafer, is widely used in wafer manufacturing process, especially etching, Physical Vapor Deposition (PVD), Chemical Vapor Deposition (CVD) and other core processes.
[0003] Electrostatic Chuck surface is distributed with electrode and airflow channel, and the electrode forms electrostatic force electric field and wafer back contact, electrode contact position current density is big, electrostatic suction force concentrates, wafer and electrostatic chuck are closely combined, and the local pressure of electrostatic chuck surface is big, will cause electrode to scratch wafer back, in addition, the distribution of electrode and airflow channel of current electrostatic chuck is unreasonable, leading to poor heat dissipation effect.With the increasingly wide application of large-size packaging form FCBGA (Flip Chip Ball Grid Array), the influence caused by wafer back scratch is increasingly highlighted.Based on cost consideration, FCBGA wafer does not do back thinning, and scratch mark will be kept on the back of final package, which affects the identification of package laser marking and causes yield loss to final packaging product. UTILITY MODEL CONTENT
[0004] To solve the technical problem that the prior art electrostatic chuck design does not fully consider wafer scratch and poor heat dissipation effect, the utility model discloses an electrostatic chuck and semiconductor processing machine platform.
[0005] In one aspect, the utility model discloses an electrostatic chuck for adsorbing and fixing a to-be-adsorbed object, comprising a substrate and an electrode, wherein:
[0006] The substrate is used for carrying the to-be-adsorbed object, and the substrate is provided with at least one through hole;
[0007] The electrode is arranged above the substrate and contacts at least a partial region of the substrate, and the electrode is used for generating electrostatic suction force to adsorb and fix the to-be-adsorbed object on the substrate;
[0008] The electrode divides the substrate into a plurality of unit carrying regions, and the electrode corresponding to each unit carrying region has a preset shape gap between the substrate, and the preset shape gap and the through hole form an airflow channel to provide a flow path for process gas, so that the process gas flows along the flow path between the substrate and the to-be-adsorbed object.
[0009] Further, the electrostatic chuck further comprises a dielectric layer, the dielectric layer is arranged above the substrate, and the electrode is arranged in the dielectric layer.
[0010] Further, the substrate comprises a first surface and a second surface opposite to each other, the first surface is used for carrying the object to be adsorbed, and the second surface is connected with a gas pipeline to obtain the process gas.
[0011] Further, the at least one through hole of the substrate is located in the unit carrying area.
[0012] Further, the electrode comprises a first electrode extending along a first direction and a second electrode extending along a second direction, and the first electrode and the second electrode divide the substrate into a plurality of unit carrying areas.
[0013] Further, the first direction is perpendicular to the second direction, and the first electrode and the second electrode divide the substrate into a plurality of rectangular unit carrying areas.
[0014] Further, the intersection of the first electrode and the second electrode is at least partially in contact with the substrate.
[0015] Further, the first electrode and the second electrode corresponding to each rectangular unit carrying area are provided with a preset shape interval in a direction towards the substrate.
[0016] Further, the electrostatic chuck further comprises a power supply module connected with the electrode, and the power supply module is used for supplying power to the electrode to generate electrostatic suction force.
[0017] In another aspect, the utility model provides a kind of semiconductor processing machine table, including the electrostatic chuck as described above.
[0018] By using the above technical scheme, the utility model has the following beneficial effects:
[0019] The electrostatic chuck has the following beneficial effects: the electrode is designed to divide the substrate into a plurality of unit carrying areas, each unit carrying area is a separate force unit, and the stress is balanced and adsorbed, the local pressure is small, and damage to the wafer is avoided; the electrode corresponding to each unit carrying area has a preset shape interval with the substrate, an airflow channel is formed between the preset shape interval and the through hole of the substrate, and the airflow channel is used to provide a flow path for the process gas, so that the process gas flows along the flow path between the substrate and the object to be adsorbed, and the heat dissipation effect on the wafer is enhanced. BRIEF DESCRIPTION OF DRAWINGS
[0020] In order to more clearly illustrate the technical solutions in the embodiments of the utility model, the following will briefly introduce the drawings needed to be used in the embodiment description, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creative labor.
[0021] Figure 1 is a schematic diagram of a furnace tube device in the prior art;
[0022] Figure 2 is a schematic diagram of a flange interface with multiple gas inlet angles in the prior art;
[0023] Figure 3 is a schematic diagram of a composite flange structure according to an embodiment of the present application;
[0024] Figure 4 is a schematic diagram of a composite flange structure connection cross section according to an embodiment of the present application.
[0025] The following is a supplementary description of the drawings:
[0026] 1, base plate; 2, electrode; 3, through hole; 4, pre-set shape interval. DETAILED DESCRIPTION
[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0028] The term "one embodiment" or "an embodiment" as used herein means that a particular feature, structure, or characteristic described can be included in at least one implementation of the present application. In the description of the application, it should be understood that the terms "upper", "lower", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited by "first", "second" can be explicitly or implicitly included one or more of the features. Moreover, the terms "first", "second", etc. are used to distinguish similar objects, and do not necessarily describe a particular order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.
[0029] An electrostatic chuck (ESC) is a clamping tool that uses electrostatic adsorption principle to fix a wafer, avoids applying physical force to the wafer, and is widely used in wafer manufacturing processes, especially in core processes such as etching, physical vapor deposition (PVD), chemical vapor deposition (CVD), etc.
[0030] There are three main adsorption principles of electrostatic chuck: Coulomb force, Johnson-Rahbek force and gradient force. The electrostatic chuck usually includes a substrate and an electrode, the substrate provides structural support for the entire electrostatic chuck, carries the wafer to be adsorbed and fixed, and has gas holes formed on the substrate to form an airflow channel, through which cooling gas can be introduced to assist wafer cooling, which is particularly important for temperature-sensitive process steps.
[0031] The electrostatic chuck surface is distributed with electrodes, and the electrostatic force electric field is formed through the electrodes to contact the wafer back surface. As shown in Figure 1 , the electrode of the existing electrostatic chuck is usually designed as a closed ring, the current density at the electrode contact position is large, the wafer is tightly attached to the electrostatic chuck, the electrostatic attraction force is concentrated, and the local pressure on the surface of the electrostatic chuck is large, which may cause scratches on the wafer back surface. In addition, as shown in Figure 2 , the distribution of the electrode and the airflow channel of the existing electrostatic chuck is unreasonable, the gas holes are distributed in each independent electrode closed ring, and the single gas hole cooling airflow only flows in a single electrode closed ring, resulting in poor cooling effect. With the increasing application of large-size packaging form FCBGA (Flip Chip Ball Grid Array), the impact of wafer back surface scratches is increasingly prominent. Based on cost considerations, FCBGA wafers are not thinned on the back surface, and scratches will be left on the back surface of the final package, affecting the identification of laser marking of the package, and causing yield loss to the final package product.
[0032] In order to avoid scratches on the wafer by the electrostatic chuck, improve the wafer cooling capacity, and improve the semiconductor packaging yield, the utility model provides an electrostatic chuck and a semiconductor processing machine, which better adapt to the wafer production demand.
[0033] Reference Figure 3As shown is the structure top view of the electrostatic chuck, comprising a substrate 1 and an electrode 2, wherein: the substrate 1 is used to carry the to-be-adsorbed object; the substrate 1 is provided with at least one through hole 3; the electrode 2 is distributed above the substrate 1 and contacts at least a partial area of the substrate 1, the electrode 2 is used to generate an electrostatic adsorption force to adsorb and fix the to-be-adsorbed object on the substrate 1; the electrode 2 divides the substrate 1 into a plurality of unit carrying areas, each unit carrying area has a preset shape spacing 4 between the corresponding electrode 2 and the substrate 1, a gas flow channel is formed between the preset shape spacing 4 and the through hole 3, and the gas flow channel is used to provide a flow path for process gas to flow along the flow path between the substrate 1 and the to-be-adsorbed object.
[0034] Specifically, the substrate 1 is an important component of the electrostatic chuck and is used to carry the to-be-adsorbed object, and the to-be-adsorbed object includes a wafer or other devices in a semiconductor process. In the embodiments of the present application, the wafer is taken as an example. The selection of the substrate 1 can be determined based on factors such as thermal conductivity, insulation, stability, etc. A substrate 1 with high thermal conductivity can effectively dissipate the heat generated by the electrostatic chuck to a certain extent, thereby avoiding damage to the wafer due to excessive temperature; good insulation performance can prevent current leakage between the electrostatic chuck and the wafer, thereby ensuring the processing quality of the wafer; in addition, the substrate 1 needs to have good chemical stability to prevent damage caused by chemical substances during processing, therefore, when selecting the substrate 1, the specific application requirements and processing requirements need to be considered comprehensively, and in some embodiments, the material of the substrate 1 includes metal, ceramic, etc. The size and thickness of the substrate 1 vary depending on the application scenario and specific requirements, which are not limited here, and the edge shape of the substrate 1 can be circular, square or other customized shapes, etc.
[0035] The substrate 1 is provided with at least one through hole 3 to form a gas flow channel for heat dissipation of the wafer. In some embodiments, the electrostatic chuck is connected to a cooling gas source such as helium through an external gas pipeline, the gas pipeline delivers cooling gas to the electrostatic chuck, and the cooling gas flows through the through hole 3 to the back of the wafer to play a cooling and heat dissipation role. The distribution of the through hole 3 will be described in detail in combination with the electrode 2.
[0036] In one possible implementation, the substrate 1 includes opposite first and second faces; the first face is used to carry the to-be-adsorbed object; and the second face is connected with a gas pipeline to obtain process gas. Specifically, the substrate 1 has opposite first and second faces in the vertical direction, for example, the first face is upward and contacts the to-be-adsorbed object to carry the to-be-adsorbed object; and the second face is downward and connected with the gas pipeline to obtain process gas, and in the embodiments of the present application, the process gas includes cooling gas.
[0037] The electrodes 2 are distributed above the substrate 1 and used to generate electrostatic attraction force to fix the to-be-adsorbed object on the substrate 1. The electrodes 2 can be made of conductive material such as copper, aluminum, etc. In one possible implementation, a power supply module is further included and connected to the electrodes 2 to supply power to the electrodes 2 to make the electrodes 2 generate electrostatic attraction force. When the power supply provides voltage and current to the electrode 2 plate, an electrostatic field is generated on the electrode 2 plate. When the to-be-adsorbed object is close to the electrode 2 plate, induced charges are generated on the surface of the object and interact with the charges on the electrode 2 to generate electrostatic force, which causes the object to be adsorbed to the electrode 2 plate to fix the to-be-adsorbed object.
[0038] The electrodes 2 are in contact with the substrate 1 at least in part of the region, and the electrodes 2 divide the substrate 1 into a plurality of unit carrying regions. Each unit carrying region corresponds to a preset shape gap 4 between the electrode 2 and the substrate 1. The preset shape gap 4 and the through hole 3 form an airflow channel to provide a flow path for the process gas to flow between the substrate 1 and the to-be-adsorbed object along the flow path.
[0039] Specifically, since the electrodes 2 of the existing electrostatic chuck are usually designed as a closed ring, the current density is large at the contact position of the electrode 2, the wafer is tightly attached to the electrostatic chuck, the electrostatic attraction force is concentrated, the local pressure on the surface of the electrostatic chuck is large, and the formed suction stress can cause the back surface of the wafer to be scratched. Therefore, the electrode 2 is designed as a cross shape in the utility model, the substrate 1 is divided into a plurality of unit carrying regions, each unit carrying region is a separate force unit, the suction stress is balanced and shared, the local pressure is small, and damage to the wafer is avoided.
[0040] Reference Figure 4 As shown in the figure, each unit carrying region corresponds to a preset shape gap 4 between the electrode 2 and the substrate 1, and the electrode 2 is in contact with the substrate 1 at least in part of the region. In some embodiments, the cross section of the preset shape gap 4 can be rectangular, arc-shaped, triangular, etc., which is not limited herein. That is, the electrode 2 is not completely attached to the substrate 1, and the preset shape gap 4 and the through hole 3 can form an airflow channel to provide a flow path for the process gas to flow between the substrate 1 and the to-be-adsorbed object along the flow path in the direction of the four sides, so as to play a heat dissipation role on the wafer.
[0041] In one possible implementation, the electrode 2 includes a first electrode extending in a first direction and a second electrode extending in a second direction, and the first electrode and the second electrode divide the substrate 1 into a plurality of unit carrying regions.
[0042] Specifically, the electrode 2 has a plurality of first electrodes extending along a first direction and a plurality of second electrodes extending along a second direction, the first electrodes and the second electrodes intersect to form the overall electrode 2, and the first electrodes and the second electrodes intersecting with each other divide the substrate 1 into a plurality of unit carrying areas.
[0043] Further, the first direction is perpendicular to the second direction; the first electrodes and the second electrodes divide the substrate 1 into a plurality of rectangular unit carrying areas. For example, in some embodiments, the first direction is the x direction, the second direction is the y direction, the first electrodes and the second electrodes are perpendicular to each other, and each unit carrying area formed is a rectangle, including a square. The size of the unit carrying area can be determined according to the actual process, such as 1*1 mm. This is not limited here.
[0044] The first electrodes and the second electrodes are in contact with at least a part of the substrate 1. In one possible implementation, the intersection of the first electrodes and the second electrodes is in contact with at least a part of the substrate 1. Further, the first electrodes and the second electrodes corresponding to each rectangular unit carrying area are provided with a preset shape gap 4 in the direction towards the substrate 1. That is, the intersection of the first electrodes and the second electrodes is in contact with the substrate 1, and the first electrodes and the second electrodes have a preset shape gap 4 with the substrate 1, so as to form an electrode 2 structure with a hollow structure.
[0045] In one possible implementation, at least one through hole 3 of the substrate 1 is located in the unit carrying area. Specifically, as known from the foregoing, the first electrodes and the second electrodes intersecting with each other divide the substrate 1 into a plurality of unit carrying areas, and at least one through hole 3 is provided in the substrate 1 in the plurality of unit carrying areas. One or more through holes 3 can be provided in one unit carrying area, and a gas flow channel is formed between the preset shape gap 4 and the through hole 3. The gas flow of any through hole 3 can be diffused to all electrode 2 covered areas through the gas flow channel. Compared with the prior art in which the through hole 3 is distributed in each independent electrode 2 closed loop, and the heat dissipation gas flow of a single through hole 3 only flows in a single electrode 2 closed loop, resulting in poor heat dissipation effect, the embodiments of the present application can achieve better heat dissipation effect.
[0046] In one possible implementation, a dielectric layer (not shown in the figure) is further included, the dielectric layer is stacked above the substrate 1, and the electrode 2 is arranged in the dielectric layer. Specifically, the dielectric layer mainly plays a role of insulation and isolation, preventing the electrode 2 of the electrostatic chuck from being short-circuited with the object to be adsorbed. The dielectric layer is usually made of insulating materials such as ceramics or plastics. When the electrode 2 is powered on, the electric charge in the dielectric layer is polarized to form an electrostatic field. When the object to be adsorbed approaches the electrostatic chuck, the electrostatic field acts on the surface of the object to make the surface of the object generate an opposite charge. Due to the mutual attraction between the charges, the object to be adsorbed is adsorbed on the electrostatic chuck.
[0047] In another aspect, the utility model provides a kind of semiconductor processing platform, including electrostatic chuck as described above.
[0048] Through the above embodiment, the electrode is designed to divide the substrate into multiple unit bearing areas, each unit bearing area is a separate force unit, which shares the balance suction stress, the local pressure is smaller, and damage to the wafer is avoided;Each unit bearing area corresponding electrode has a preset shape gap between the substrate, the preset shape gap and the through hole of the substrate form an airflow channel, which is used to provide a flow path for process gas, so that the process gas flows along the flow path between the substrate and the adsorbed object, enhancing the heat dissipation effect of the wafer.Compared with the closed ring design of the electrode of the electrostatic chuck in the prior art, local suction stress may cause scratches on the back of the wafer, the through holes are distributed in each independent electrode closed ring, and the single through hole cooling airflow only flows in a single electrode closed ring, resulting in poor heat dissipation effect.The electrostatic chuck of the utility model can not only avoid scratches on the wafer by the electrostatic chuck, but also improve the heat dissipation capacity of the wafer and improve the yield of semiconductor packaging.
[0049] The above is only the preferred embodiment of the utility model, and is not used to limit the utility model, any modification, equivalent replacement, improvement, etc. within the spirit and principles of the utility model should be included in the protection scope of the utility model.
Claims
1. An electrostatic chuck for adsorbing and fixing an object to be adsorbed, characterized in that, The electrostatic chucking device comprises a substrate (1) and an electrode (2): The substrate (1) is used for carrying the object to be adsorbed; the substrate (1) is provided with at least one through hole (3); The electrode (2) is distributed above the substrate (1) and contacts at least a part of the substrate (1); the electrode (2) is used for generating electrostatic adsorption force to adsorb and fix the object to be adsorbed on the substrate (1); The electrode (2) divides the substrate (1) into a plurality of unit carrying areas; each unit carrying area is provided with a preset shape gap (4) between the corresponding electrode (2) and the substrate (1); the preset shape gap (4) and the through hole (3) form an air flow channel to provide a flow path for the process gas to flow between the substrate (1) and the object to be adsorbed.
2. The electrostatic chuck of claim 1, wherein, Further comprising a dielectric layer, the dielectric layer is stacked above the substrate (1); the electrode (2) is arranged in the dielectric layer.
3. The electrostatic chuck of claim 1, wherein, The substrate (1) comprises a first surface and a second surface opposite to each other; the first surface is used for carrying the object to be adsorbed; the second surface is connected with a gas pipeline to obtain the process gas.
4. The electrostatic chuck of claim 3, wherein, The at least one through hole (3) of the substrate (1) is located in the unit carrying area.
5. The electrostatic chuck of claim 1, wherein, The electrode (2) comprises a first electrode extending in a first direction and a second electrode extending in a second direction; the first electrode and the second electrode divide the substrate (1) into a plurality of unit carrying areas.
6. The electrostatic chuck of claim 5, wherein, The first direction is perpendicular to the second direction; the first electrode and the second electrode divide the substrate (1) into a plurality of rectangular unit carrying areas.
7. The electrostatic chuck of claim 6, wherein, The intersection of the first electrode and the second electrode contacts at least a part of the substrate (1).
8. The electrostatic chuck of claim 6, wherein, The first electrode and the second electrode corresponding to each rectangular unit carrying area are provided with the preset shape gap (4) in the direction towards the substrate (1).
9. The electrostatic chuck of claim 1, wherein, Further comprising a power supply module, the power supply module is connected with the electrode (2) to supply power to the electrode (2) to generate electrostatic adsorption force.
10. A semiconductor processing chamber, comprising: The electrostatic chucking device comprises a substrate (1) and an electrode (2): The substrate (1) is used for carrying the object to be adsorbed; the substrate (1) is provided with at least one through hole (3); The electrode (2) is distributed above the substrate (1) and contacts at least a part of the substrate (1); the electrode (2) is used for generating electrostatic adsorption force to adsorb and fix the object to be adsorbed on the substrate (1); The electrode (2) divides the substrate (1) into a plurality of unit carrying areas; each unit carrying area is provided with a preset shape gap (4) between the corresponding electrode (2) and the substrate (1); the preset shape gap (4) and the through hole (3) form an air flow channel to provide a flow path for the process gas to flow between the substrate (1) and the object to be adsorbed. Further comprising a dielectric layer, the dielectric layer is stacked above the substrate (1); the electrode (2) is arranged in the dielectric layer. The substrate (1) comprises a first surface and a second surface opposite to each other; the first surface is used for carrying the object to be adsorbed; the second surface is connected with a gas pipeline to obtain the process gas. The at least one through hole (3) of the substrate (1) is located in the unit carrying area. The electrode (2) comprises a first electrode extending in a first direction and a second electrode extending in a second direction; the first electrode and the second electrode divide the substrate (1) into a plurality of unit carrying areas. The first direction is perpendicular to the second direction; the first electrode and the second electrode divide the substrate (1) into a plurality of rectangular unit carrying areas. The intersection of the first electrode and the second electrode contacts at least a part of the substrate (1). The first electrode and the second electrode corresponding to each rectangular unit carrying area are provided with the preset shape gap (4) in the direction towards the substrate (1). Further comprising a power supply module, the power supply module is connected with the electrode (2) to supply power to the electrode (2) to generate electrostatic adsorption force. The electrostatic chucking device comprises a substrate (1) and an electrode (2): The substrate (1) is used for carrying the object to be adsorbed; the substrate (1) is provided with at least one through hole (3); The electrode (2) is distributed above the substrate (1) and contacts at least a part of the substrate (1); the electrode (2) is used for generating electrostatic adsorption force to adsorb and fix the object to be adsorbed on the substrate (1); The electrode (2) divides the substrate (1) into a plurality of unit carrying areas; each unit carrying area is provided with a preset shape gap (4) between the corresponding electrode (2) and the substrate (1); the preset shape gap (4) and the through hole (3) form an air flow channel to provide a flow path for the process gas to flow between the substrate (1) and the object to be adsorbed. Further comprising a dielectric layer, the dielectric layer is stacked above the substrate (1); the electrode (2) is arranged in the dielectric layer. The substrate (1) comprises a first surface and a second surface opposite to each other; the first surface is used for carrying the object to be adsorbed; the second surface is connected with a gas pipeline to obtain the process gas. The at least one through hole (3) of the substrate (1) is located in the unit carrying area. The electrode (2) comprises a first electrode extending in a first direction and a second electrode extending in a second direction; the first electrode and the second electrode divide the substrate (1) into a plurality of unit carrying areas. The first direction is perpendicular to the second direction; the first electrode and the second electrode divide the substrate (1) into a plurality of rectangular unit carrying areas. The intersection of the first electrode and the second electrode contacts at least a part of the substrate (1). The first electrode and the second electrode corresponding to each rectangular unit carrying area are provided with the preset shape gap (4) in the direction towards the substrate (1). Further comprising a power supply module, the power supply module is connected with the electrode (2) to supply power to the electrode (2) to generate electrostatic adsorption force. The electrostatic chucking device comprises a substrate (1) and an electrode (2):