Device and method for reducing stress of extreme ultraviolet multilayer film
Through the device that performs segmented thermal annealing treatment in real time during the coating process, the problem of complex annealing operations in the prior art and difficult to reduce stress in the substrate is solved, and the stress reduction and reflectivity increase of the extreme ultraviolet multilayer film is achieved, and higher quality optical components are provided.
Patent Information
- Application Number
- CN202411868039.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2025-03-21
AI Technical Summary
The prior art After plating an extremely ultraviolet multilayer film, the substrate needs to be taken out of the coating chamber for thermal annealing. The operation is complicated and it is difficult to effectively reduce the stress of the film, resulting in a decrease in reflectivity.
A device including a base, a mounting plate, a rotary driving mechanism and annealing device is designed to allow the substrate to undergo a segmented thermal annealing process in real time during the coating process, and the annealing device is driven to rotate with the substrate through the rotary driving mechanism to achieve uniform heating of the substrate.
Significantly reduces the stress of extreme UV multilayer films, improves reflectivity, simplifies operational processes, improves coating efficiency, and provides higher quality optical components.
Smart Images
Figure CN119663222A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of extreme ultraviolet lithography, and in particular to a device and method for reducing stress of an extreme ultraviolet multilayer film. Background Art
[0002] EUV multilayer films are widely used in today's semiconductor industry and are one of the important optical components. In particular, Mo / Si multilayer films with excellent reflective properties play an extremely important role in laser plasma diagnosis, EUV lithography, etc. This film has a high reflectivity efficiency, but because more layers need to be plated to achieve this index, there will be greater stress after the film is prepared.
[0003] At present, the method of controlling film stress often adopts thermal annealing treatment, that is, after the substrate coating is completed, the substrate is taken out of the coating chamber and placed in a special annealing chamber for thermal annealing treatment. The existing treatment method is inconvenient and the operation is complicated. Moreover, for substrates that need to be coated with thicker films, heat treatment is performed after the coating is completed. The residual stress of the film still maintains a very high level, and it will cause the reflectivity to decrease. The reflectivity directly affects the efficiency of the lithography system. Summary of the invention
[0004] The purpose of the present invention is to provide a device and method for reducing the stress of extreme ultraviolet multilayer films to solve the problems existing in the above-mentioned prior art, which can reduce the stress of extreme ultraviolet multilayer films prepared by magnetron sputtering, improve the reflectivity of extreme ultraviolet multilayer films, and provide higher quality optical elements for lithography applications.
[0005] To achieve the above object, the present invention provides the following solutions:
[0006] The present invention provides a device for reducing stress of an extreme ultraviolet multilayer film, comprising a base, a mounting plate, a rotational driving mechanism and an annealing device, wherein the mounting plate is connected to the base, a substrate is fixed on the mounting plate, and an annealing device for heating the substrate is installed between the substrate and the mounting plate, the annealing device comprises a spacer plate and a heating mechanism, one side of the spacer plate is tightly fitted with the substrate, and the other side of the spacer plate is tightly fitted with the heating mechanism, the heating mechanism is used to heat the spacer plate and then heat the substrate, the rotational driving mechanism is connected to the mounting plate and can drive the mounting plate to drive the annealing device and the substrate to perform rotational motion relative to the base.
[0007] Preferably, it further comprises a clamping device, through which the substrate is fixedly connected to the mounting plate.
[0008] Preferably, the spacer plate is made of oxygen-free copper plate.
[0009] Preferably, the heating mechanism comprises a spiral disc heating wire and a power supply assembly electrically connected to the spiral disc heating wire, and the spiral disc heating wire is fixedly connected to the mounting plate.
[0010] Preferably, the heating mechanism further comprises a temperature sensor, and the temperature sensor is fixedly disposed on the partition plate.
[0011] The present invention also provides a method for using the device for reducing stress of an extreme ultraviolet multilayer film, comprising the following steps:
[0012] Step 1: Place the base on a trolley that moves back and forth in a straight line in a vacuum coating chamber of magnetron sputtering, fix the substrate on a mounting plate, and make the substrate fit tightly with the spacer plate;
[0013] Step 2: The cathode target is ignited and the rotary drive mechanism is started at the same time. The substrate is rotated under the action of the mounting plate to uniformly deposit target ions. According to the characteristics of the required thin film, the substrate can be heated and cooled by the annealing device during the coating process; or after the substrate is coated, the substrate can be heated and cooled by the annealing device;
[0014] Step three, after the temperature rise and fall treatment, the coating is completed.
[0015] Compared with the prior art, the present invention has achieved the following technical effects:
[0016] The present invention provides a device and method for reducing the stress of extreme ultraviolet multilayer films. In the vacuum coating chamber of magnetron sputtering, the cathode target is ignited, and the rotating drive mechanism drives the mounting plate to drive the annealing device and the substrate to rotate relative to the base, and the substrate uniformly deposits the target material ions in a rotating manner. Unlike the traditional magnetron sputtering, the substrate needs to be taken out of the coating chamber after the coating is completed and then placed in the annealing chamber for annealing. The present invention can perform segmented thermal annealing in real time during the coating process, significantly reducing the stress of the extreme ultraviolet multilayer film, and the reflectivity decreases much lower than the conventional stress elimination method, thereby providing higher quality optical elements in the field of semiconductor technology, especially in lithography applications; or after the coating is completed, the substrate is directly subjected to thermal annealing in the coating chamber without removing the substrate, which is simple to operate and more efficient; and the heating mechanism heats the spacer plate, and the spacer plate is in direct contact with the substrate. The heating method has a faster heating speed and does not need to be too high. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0018] Figure 1 A schematic diagram of a device for reducing stress in an extreme ultraviolet multilayer film;
[0019] Figure 2 Exploded view of a device for reducing stress in EUV multilayer films.
[0020] In the figure: 1-base; 2-mounting plate; 3-rotation drive mechanism; 4-annealing device; 41-spacer plate; 42-heating mechanism; 5-substrate; 6-clamping device; 61-annular cover plate; 62-gasket; 63-annular sleeve. DETAILED DESCRIPTION
[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0022] The purpose of the present invention is to provide a device and method for reducing the stress of extreme ultraviolet multilayer films to solve the problems existing in the above-mentioned prior art, which can reduce the stress of extreme ultraviolet multilayer films prepared by magnetron sputtering, improve the reflectivity of extreme ultraviolet multilayer films, and provide higher quality optical elements for lithography applications.
[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0024] Example 1
[0025] This embodiment provides a device for reducing stress of an EUV multilayer film, such as Figure 1-2As shown, it includes a base 1, a mounting plate 2, a rotation driving mechanism 3 and an annealing device 4, the mounting plate 2 is connected to the base 1, the substrate 5 is fixed on the mounting plate 2, and an annealing device 4 for heating the substrate 5 is installed between the substrate 5 and the mounting plate 2, the annealing device 4 includes a spacer plate 41 and a heating mechanism 42, one side of the spacer plate 41 is tightly fitted with the substrate 5, and the other side of the spacer plate 41 is tightly fitted with the heating mechanism 42, the heating mechanism 42 is used to heat the spacer plate 41, and then heat the substrate 5, the rotation driving mechanism 3 is connected to the mounting plate 2, and can drive the mounting plate 2 to drive the annealing device 4 and the substrate 5 to rotate relative to the base 1. In the vacuum coating chamber of magnetron sputtering, the cathode target is ignited, and the rotary drive mechanism 3 drives the mounting plate 2 to drive the annealing device 4 and the substrate 5 to rotate relative to the base 1. The substrate 5 uniformly deposits the target ions in a rotating manner. After coating for a certain period of time, the substrate 5 is subjected to thermal annealing by the annealing device 4, and then continues to be coated for a period of time, and then undergoes thermal annealing, which is repeated multiple times until the coating is completed. Different from the conventional magnetron sputtering method in which the substrate needs to be taken out of the coating chamber after coating and then placed in the annealing chamber for annealing, the present invention During the coating process, segmented thermal annealing is performed in real time to significantly reduce the stress of the EUV multilayer film. At the same time, the reflectivity decreases much lower than the conventional stress elimination method, thereby providing higher quality optical elements in the field of semiconductor technology, especially in lithography applications; or after the coating is completed, the substrate 5 is directly subjected to thermal annealing in the coating chamber without removing the substrate 5, which is simple to operate and more efficient; and the heating mechanism 42 heats the spacer plate 41, and the spacer plate 41 is in direct contact with the substrate 5. The heating speed is fast and the temperature does not need to be too high. The annealing device 4 rotates together with the mounting plate 2, and the temperature can be raised and lowered during the rotation of the substrate 5, which can reduce the size of the device, reduce the space occupancy rate of the vacuum coating chamber, increase the number of coatings, and improve efficiency.
[0026] In the implementation of this embodiment, it is further preferred that the device for reducing the stress of the EUV multilayer film further includes a clamping device 6, and the substrate 5 is fixedly connected to the mounting plate 2 through the clamping device 6. The clamping device 6 can fix the substrate 5 to the mounting plate 2 according to the requirements of different substrates 5. For example, Figure 2 As shown, the clamping device 6 includes an annular cover plate 61, a gasket 62 and an annular sleeve 63. The annular sleeve 63 is fixedly mounted outside the substrate 5. One end of the annular sleeve 63 is fixedly connected to the annular cover plate 61, and a gasket 62 is arranged between the annular cover plate 61 and the substrate 5. The other end of the annular sleeve 63 is fixed to the mounting plate 2.
[0027] In the implementation of this embodiment, it is further preferred that the material of the partition plate 41 is an oxygen-free copper plate. The oxygen-free copper plate is heated evenly and does not release excess gas when heated in a vacuum.
[0028] In the implementation of this embodiment, it is further preferred that the heating mechanism 42 includes a spiral disc heating wire and a power supply component electrically connected to the spiral disc heating wire, and the spiral disc heating wire is fixedly connected to the mounting plate 2. A lead wire is led out from the rear end of the spiral disc heating wire, and merges with the lead wire of the rotary drive mechanism 3, and is led out of the vacuum coating chamber through the vacuum port and connected to an external controller.
[0029] In the implementation of this embodiment, it is further preferred that the heating mechanism 42 further comprises a temperature sensor, and the temperature sensor is fixedly disposed on the partition plate 41. The temperature sensor can monitor the temperature of the partition plate 41, so as to grasp the temperature condition in real time.
[0030] Example 2
[0031] This embodiment provides a method for reducing stress of an extreme ultraviolet multilayer film using the device of embodiment 1, comprising the following steps:
[0032] Step 1: Place the base 1 on a trolley that moves back and forth in a straight line in a vacuum coating chamber of magnetron sputtering, fix the substrate 5 on the mounting plate 2, and make the substrate 5 fit tightly with the spacer plate 41;
[0033] Step 2, the cathode target is ignited, and the rotary drive mechanism 3 is started at the same time. The substrate 5 is rotated under the action of the mounting plate 2 to uniformly deposit the target ions. According to the characteristics of the required film, the substrate 5 can be subjected to a temperature rise and fall treatment by the annealing device 4 during the coating process; when the number of substrate coating layers is large, the substrate 5 can be subjected to a temperature rise and fall treatment by the annealing device 4 during the coating process. Take the substrate plated with 50 cycles of Mo / Si as an example (one cycle is one cycle for a layer of Mo and one layer of Si on the substrate), after 15-25 cycles of coating on the substrate, the substrate 5 is subjected to a temperature rise and fall treatment by the annealing device 4, that is, the substrate is subjected to subsequent coating while performing thermal annealing treatment, and the thermal treatment is also terminated when the coating is completed, which can significantly reduce the stress of the extreme ultraviolet multilayer film; or after the substrate 5 is coated, the substrate 5 is subjected to a temperature rise and fall treatment by the annealing device 4, and after the coating is completed, the temperature rise and fall annealing treatment is directly performed inside the coating chamber, and the substrate does not need to be removed and changed during the period, which is simple to operate and more efficient.
[0034] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.
Claims
1. A device for reducing stress of an extreme ultraviolet multilayer film, characterized in that: It includes a base, a mounting plate, a rotation drive mechanism and an annealing device, the mounting plate is connected to the base, the substrate is fixed on the mounting plate, and the annealing device for heating the substrate is installed between the substrate and the mounting plate, the annealing device includes a spacer plate and a heating mechanism, one side of the spacer plate is tightly fitted with the substrate, and the other side of the spacer plate is tightly fitted with the heating mechanism, the heating mechanism is used to heat the spacer plate and then heat the substrate, the rotation drive mechanism is connected to the mounting plate, and can drive the mounting plate to drive the annealing device and the substrate to rotate relative to the base.
2. The device for reducing stress of an extreme ultraviolet multilayer film according to claim 1, characterized in that: It also includes a clamping device, through which the substrate is fixedly connected to the mounting plate.
3. The device for reducing stress of an extreme ultraviolet multilayer film according to claim 1, characterized in that: The material of the spacer plate is oxygen-free copper plate.
4. The device for reducing stress of an extreme ultraviolet multilayer film according to claim 1, characterized in that: The heating mechanism comprises a spiral disc heating wire and a power supply component electrically connected to the spiral disc heating wire, and the spiral disc heating wire is fixedly connected to the mounting plate.
5. The device for reducing stress of an extreme ultraviolet multilayer film according to claim 4, characterized in that: The heating mechanism further comprises a temperature sensor, and the temperature sensor is fixedly arranged on the partition plate.
6. A method for reducing stress of an extreme ultraviolet multilayer film using the device according to any one of claims 1 to 5, characterized in that: The steps include: Step 1: Place the base on a trolley that moves back and forth in a straight line in a vacuum coating chamber of magnetron sputtering, fix the substrate on a mounting plate, and make the substrate fit tightly with the spacer plate; Step 2: The cathode target is ignited and the rotary drive mechanism is started at the same time. The substrate is rotated under the action of the mounting plate to uniformly deposit target ions. According to the characteristics of the required thin film, the substrate can be heated and cooled by the annealing device during the coating process; Alternatively, after the substrate is coated, the substrate is subjected to a temperature raising and lowering process by an annealing device; Step three, after the temperature rise and fall treatment, the coating is completed.