Semiconductor application-oriented multi-size wafer acoustic levitation device and attitude measurement system

Abstract

The invention discloses a multi-size wafer acoustic levitation device for semiconductor application and an attitude measurement system, and belongs to the technical field of semiconductor processing, the multi-size wafer acoustic levitation device comprises a base and a planet support, the planet support is connected with the base, a transducer is installed on the planet support, and the transducer is connected with a vibrator; the vibrator comprises a first boss and a second boss, the first boss and the second boss are concentrically arranged, the second boss is provided with a gradually-changed inclined plane, the diameter of the second boss is smaller than that of the first boss, and the thickness of the second boss is larger than that of the first boss; the transducer transmits vibration to the vibrator, the vibrator is excited to generate high-order bending by adjusting the size and thickness of the first boss and the second boss, surrounding air is extruded to form regular high-pressure area and low-pressure area distribution, and the multi-size wafers placed on the vibrator are made to suspend. Acoustic levitation is adopted to achieve multi-size wafer levitation control, scratching of the wafer and an actuator is avoided, a wafer levitation measurement system is designed, and wafer levitation height and pose measurement is achieved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor processing technology, and in particular to a multi-size wafer acoustic levitation device and attitude measurement system for semiconductor applications. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Semiconductor processing is a crucial process in chip manufacturing and a vital link in high-end equipment manufacturing. Contact friction damage, precision dimensional deviations, and contaminant residue are common processes and defects in wafer fabrication. Among these, contact-type processing, where the processing equipment's actuators come into contact with the wafer, can cause stress deformation and friction damage, resulting in surface contamination and scratches. This compromises processing precision, impacts production capacity and yield, and severely hinders the development of the chip industry, especially advanced chip manufacturing.

[0004] To address issues such as friction, contamination, and scratches caused by contact-based processing methods, existing technologies include air suspension, electromagnetic suspension, and temporary back-side coating. However, these technologies still have unresolved problems. Air suspension relies on high-pressure airflow to form a uniform gas film between the wafer and the substrate, achieving non-contact support and drive through pressure balance of the gas film. Its stability depends entirely on the uniformity and consistency of the gas film, making it highly susceptible to environmental factors and difficult to control precisely. Electromagnetic systems, due to the lack of ferromagnetism in non-magnetic wafers (such as silicon, silicon carbide, gallium nitride, and other mainstream semiconductor materials), cannot directly couple with the magnetic field of an electromagnetic system. The main problems with temporary back-side coating in wafer processing are warpage and scratches, adhesive / film residue and particles, and poor compatibility with ultra-thin wafers. Summary of the Invention

[0005] To address the aforementioned issues, this invention proposes a multi-size wafer acoustic levitation device and attitude measurement system for semiconductor applications. The device employs acoustic levitation to achieve multi-size wafer levitation control, avoiding scratching between the wafer and the actuator. Furthermore, a wafer levitation measurement system is designed to measure the wafer levitation height and orientation.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a multi-size wafer acoustic levitation device for semiconductor applications, comprising a base and a planetary support, wherein the planetary support is connected to the base via a supporting circular tube, a transducer is mounted on the planetary support, and the top of the transducer is connected to a vibrator. The vibrator includes a first boss and a second boss, which are concentrically arranged. The second boss has a gradually tapered slope, and its diameter is smaller than that of the first boss, while its thickness is greater than that of the first boss. The transducer transmits vibrations to the vibrator. By adjusting the size and thickness of the first and second protrusions, the vibrator is excited to produce higher-order bending, which compresses the surrounding air to form a regular distribution of high-pressure and low-pressure zones, causing multi-sized wafers placed on the vibrator to levitate.

[0007] As a further implementation, the vibrator is provided with a cylindrical countersunk hole, and a bolt is installed in the cylindrical countersunk hole. The bolt is used to connect the transducer and the vibrator.

[0008] As a further implementation, when a high-frequency AC voltage is applied to the transducer, the transducer converts the electrical signal into periodic longitudinal vibration through the piezoelectric effect.

[0009] As a further implementation, when the vibration is transmitted from the transducer to the vibrator, the longitudinal vibration is converted into bending vibration by the vibrator.

[0010] As a further implementation, the wafer reaches a suspended state when the pressure difference between the upper and lower surfaces of the wafer is balanced by gravity.

[0011] As a further implementation, when the vibrator undergoes high-order bending, there are multiple high-pressure and low-pressure zones, which suspend wafers of different sizes at the corresponding positions.

[0012] As a further implementation, adjusting the size and thickness of the first and second protrusions to adjust the stiffness of the vibrator is beneficial for stimulating higher-order bending of the vibrator.

[0013] As a further implementation, three steps of different heights are formed on the bottom surface of the vibrator by setting the first and second protrusions.

[0014] As a further implementation, the first step is located in the central region of the oscillator, with the greatest thickness, and approximately in-phase plunger motion. The second step is located in the middle region of the oscillator, with a reduced thickness and lower stiffness compared to the first step, making it easy to bend and capable of inducing higher-order bending through the oscillator. The third step is located in the outermost region of the oscillator, with the smallest thickness and lowest stiffness compared to the first two protrusions, and can generate large deformation on the outside of the oscillator, realizing the force on the outside of the wafer.

[0015] A second aspect of the present invention provides a multi-size wafer attitude measurement system for semiconductor applications. Based on the first aspect of the present invention, a multi-size wafer acoustic levitation device for semiconductor applications includes a first laser displacement sensor, a second laser displacement sensor, and a third laser displacement sensor. The three laser displacement sensors are used individually to measure the levitation height of the wafer at different positions. When the first laser displacement sensor, the second laser displacement sensor, and the third laser displacement sensor are combined, lasers are emitted to determine the height of three points on the wafer surface, and the wafer attitude can be determined based on the three-point positioning.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention discloses a multi-size wafer acoustic levitation device and attitude measurement system for semiconductor applications. Addressing the problems of friction, contamination, and scratches caused by contact processing methods, this invention designs a multi-size wafer acoustic levitation device and measurement system for semiconductor processing. Through variable stiffness design, it can induce / excite a vibrator to generate high-order bending vibration modes, achieving levitation effects for wafers of various sizes. The wafer levitation height is determined by a laser sensor. Based on the three-point positioning principle, non-contact measurement of the wafer's levitation posture can be achieved. Furthermore, the designed multi-size wafer acoustic levitation device and measurement system also has the advantages of small size, high integration, low manufacturing cost, and customizability, making it easily integrated into various processes and stages of wafer manufacturing, processing, and transportation. It can provide a completely new approach to wafer transport in semiconductor processing. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] Figure 1 This is a schematic diagram of the structure of the multi-size wafer acoustic levitation device for semiconductor applications according to the present invention; Figure 2 This is a schematic diagram of the structure of the vibrator of the multi-size wafer acoustic levitation device of the present invention; Figure 3 This is a schematic diagram of the vibrator modes and suspension principle of the present invention; Figure 4 A schematic diagram showing the suspension of wafers of different sizes; Figure 5 This is a schematic diagram of the structure of the multi-size wafer attitude measurement system for semiconductor applications according to the present invention.

[0019] Among them, 1. base; 2. supporting round tube; 3. planetary support; 4. transducer; 5. vibrator; 51. first boss; 52. cylindrical countersunk hole; 53. second boss; 6. wafer; 7. measurement system; 71. first laser displacement sensor; 72. second laser displacement sensor; 73. third laser displacement sensor. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0023] Example 1 like Figure 1 As shown, this embodiment provides a multi-size wafer acoustic levitation device for semiconductor applications, including a base 1 and a planetary support 3. The planetary support 3 is connected to the base 1 through a supporting circular tube 2. A transducer 4 is installed on the planetary support 3, and the top of the transducer 4 is connected to a vibrator 5. like Figure 2 As shown, the vibrator 5 includes a first boss 51 and a second boss 53. The first boss 51 and the second boss 53 are concentrically arranged. The second boss 53 has a gradually changing slope, and its diameter is smaller than that of the first boss 51, while its thickness is greater than that of the first boss 51. The transducer 4 transmits the vibration to the vibrator 5. The stiffness of the vibrator 5 is adjusted by adjusting the size and thickness of the first protrusion 51 and the second protrusion 53, which excites the vibrator 5 to produce a higher order bending, compressing the surrounding air to form a regular distribution of high pressure and low pressure areas, so that the multi-size wafers 6 placed on the vibrator 5 are suspended.

[0024] The vibrator 5 is provided with a cylindrical countersunk hole 52, and a bolt is installed in the cylindrical countersunk hole 52. The bolt is used to connect the transducer 4 and the vibrator 5. This enables quick and convenient conversion or replacement of the transducer 4 and the vibrator 5.

[0025] The second protrusion 53 is located at the center of the vibrator 5 and is thicker than the first protrusion 51. It has a gradually tapered slope. The advantages of this design are as follows: First, the second protrusion 53 is located in the central region, allowing the transducer 4 to transmit a larger amount of energy. The thicker protrusion size allows the vibration phase within the protrusion area to be similar, approximating piston motion, thereby forming a large-scale high-energy / high-pressure zone / low-pressure zone (depending on the vibration period), which is beneficial to improving the levitation ability. Second, due to the strong vibration, the larger protrusion thickness can effectively prevent fatigue failure. At the same time, the gradually tapered slope can prevent abrupt changes in the force transmission from the transducer 4 to the surface of the vibrator 5.

[0026] The first protrusion 51 is located in the middle region of the vibrator 5 and is thinner than the second protrusion 53 in the middle. Since thinner thickness means lower stiffness, this region is more prone to bending than the position of the second protrusion 53.

[0027] By setting the first protrusion 51 and the second protrusion 53, three steps of different heights are formed on the bottom surface of the oscillator 5. The first step is located in the central region of the oscillator 5, with the greatest thickness, and approximately in-phase plunger motion. The second step is located in the middle region of the oscillator 5, with a reduced thickness compared to the first step, lower stiffness, and easy bending, which can induce higher-order bending through the oscillator 5. The third step is located in the outermost region of the oscillator 5, with the smallest thickness and lowest stiffness compared to the first two protrusions, which can generate large deformation on the outer side of the oscillator 5, realizing the force on the outer side of the wafer 6.

[0028] like Figure 3 As shown, the vibrator 5's modes and suspension principle are as follows: When a high-frequency AC voltage is applied to the transducer 4, the transducer 4 converts the electrical signal into periodic longitudinal vibration through the piezoelectric effect. When the vibration is transmitted from the transducer 4 to the vibrator 5, the longitudinal vibration is converted into bending vibration by the vibrator 5. The vibrator 5 resonates, and the bending vibration mode is excited. By adjusting the dimensions of the first protrusion 51 and the second protrusion 53, higher-order bending can be effectively excited in the vibrator 5. Furthermore, under near-field action, the vibrator 5 compresses the surrounding air to form sound fields of different shapes, and the shape of the sound field corresponds one-to-one with the mode. (e.g.) Figure 3 (As shown). When the pressure difference between the upper and lower surfaces of wafer 6 is balanced by gravity, wafer 6 reaches a suspended state.

[0029] The vibrator 5, by compressing air in different modes, creates sound fields of varying shapes. The shape of the sound field corresponds one-to-one with the mode. For example, if the vibrator 5 is entirely in plunger vibration mode, meaning the entire vibrator 5 vibrates up and down simultaneously in phase, the vibration energy increases exponentially with the wafer 6 size, multiplying by the square of the diameter. The existing transducer 4 has limited power and cannot provide the energy required for vibration. (The higher the frequency, the higher the vibration energy. To suppress bending, the thickness of the vibrator 5 needs to be increased; the greater the thickness, the greater the mass, and the higher the required vibration energy, which transducer 4 (the power element) cannot provide.) When the range of motion of the central plunger is reduced, the force concentrates towards the center, and the larger the size of wafer 6, the more easily the force deviates from the center of mass. Therefore, by adjusting the stiffness, higher-order bending is induced on the outside of the vibrator 5. Within one cycle, the vibrator 5 compresses air to form multiple concentric high / low pressure zones. Each high-pressure zone can provide a supporting force for wafer 6, thereby achieving stable suspension of wafers 6 of different diameters.

[0030] Schematic diagram of 6 floating wafers of different sizes as shown in Figure 6 Figure 4As shown, due to the high-order bending of the vibrator 5, meaning that the vibrator 5 can have multiple high-pressure / low-pressure regions, placing wafers 6 of different sizes in the sound field can suspend the wafers 6 at their corresponding positions. Because air damping is extremely small, the suspension is most stable when the diameter of the wafers 6 corresponds to the nodal circle position of the vibrator 5. This effectively avoids the horizontal swaying of the wafers 6 caused by the horizontal component of the bending deformation force. The vibration position can be measured using instruments such as a laser vibrometer.

[0031] When vibrator 5 deforms (e.g.) Figure 3 As shown), under the excitation of the transducer 4, the vibrator 5 forms sequentially from the inner hole outward: in-phase plunger, bending, and large outer deformation. This can balance the improvement of levitation capability with the levitation stability of multi-size wafers 6 (the outer side of the wafer is subjected to force, and the outer levitation force is relatively large).

[0032] Example 2 This embodiment provides a multi-size wafer attitude measurement system for semiconductor applications, based on a multi-size wafer acoustic levitation device for semiconductor applications in Embodiment 1. The system includes a first laser displacement sensor 71, a second laser displacement sensor 72, and a third laser displacement sensor 73. The three laser displacement sensors are used individually to measure the levitation height of the wafer 6 at different positions. When the first laser displacement sensor 71, the second laser displacement sensor 72, and the third laser displacement sensor 73 are combined, they emit lasers to determine the height of three points on the surface of the wafer 6, and the attitude of the wafer 6 can be determined based on the three-point positioning.

[0033] Measurement system schematic diagram as follows Figure 5 As shown, the measurement system 7 includes: a first laser displacement sensor 71; a second laser displacement sensor 72; and a third laser displacement sensor 73. Each laser displacement sensor can be used individually to measure the suspension height of the wafer at different positions. When the first laser displacement sensor 71, the second laser displacement sensor 72, and the third laser displacement sensor 73 are combined, they emit lasers to determine the height of three points on the surface of the wafer 6, thus determining the wafer's orientation based on these three points.

[0034] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0035] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A multi-size wafer acoustic levitation device for semiconductor applications, characterized in that, It includes a base and a planetary support, the planetary support being connected to the base via a supporting round tube, a transducer being mounted on the planetary support, and the top of the transducer being connected to a vibrator. The vibrator includes a first boss and a second boss, which are concentrically arranged. The second boss has a gradually tapered slope, and its diameter is smaller than that of the first boss, while its thickness is greater than that of the first boss. The transducer transmits vibrations to the vibrator. By adjusting the size and thickness of the first and second protrusions, the vibrator is excited to produce higher-order bending, which compresses the surrounding air to form a regular distribution of high-pressure and low-pressure zones, causing multi-sized wafers placed on the vibrator to levitate.

2. The multi-size wafer acoustic levitation device for semiconductor applications as described in claim 1, characterized in that, The vibrator is provided with a cylindrical countersunk hole, and a bolt is installed in the cylindrical countersunk hole. The bolt is used to connect the transducer and the vibrator.

3. The multi-size wafer acoustic levitation device for semiconductor applications as described in claim 1, characterized in that, When a high-frequency AC voltage is applied to the transducer, the transducer converts the electrical signal into periodic longitudinal vibration through the piezoelectric effect.

4. The multi-size wafer acoustic levitation device for semiconductor applications as described in claim 1, characterized in that, When the vibration is transmitted from the transducer to the vibrator, the longitudinal vibration is converted into bending vibration by the vibrator.

5. The multi-size wafer acoustic levitation device for semiconductor applications as described in claim 1, characterized in that, When the pressure difference between the upper and lower surfaces of a wafer is balanced by gravity, the wafer reaches a suspended state.

6. The multi-size wafer acoustic levitation device for semiconductor applications as described in claim 1, characterized in that, When the vibrator undergoes high-order bending, there are multiple high-pressure and low-pressure zones, which suspend wafers of different sizes at their corresponding positions.

7. The multi-size wafer acoustic levitation device for semiconductor applications as described in claim 1, characterized in that, Adjusting the size and thickness of the first and second protrusions to adjust the stiffness of the vibrator is beneficial for stimulating higher-order bending of the vibrator.

8. The multi-size wafer acoustic levitation device for semiconductor applications as described in claim 1, characterized in that, By setting the first and second protrusions, three steps of different heights are formed on the bottom surface of the vibrator.

9. The multi-size wafer acoustic levitation device for semiconductor applications as described in claim 8, characterized in that, The first step is located in the central region of the oscillator, with the greatest thickness, and is approximately in-phase plunger motion. The second step is located in the middle region of the oscillator, with a reduced thickness and lower stiffness compared to the first step, making it easy to bend. It can induce higher-order bending through the oscillator. The third step is located in the outermost region of the oscillator. Compared to the first two protrusions, this part has the smallest thickness and the lowest stiffness, and can generate large deformation on the outside of the oscillator, realizing the force on the outside of the wafer.

10. A multi-size wafer attitude measurement system for semiconductor applications, characterized in that, The multi-size wafer acoustic levitation device for semiconductor applications as described in any one of claims 1-9 includes a first laser displacement sensor, a second laser displacement sensor, and a third laser displacement sensor. The three laser displacement sensors are used individually to measure the levitation height of the wafer at different positions. When the first laser displacement sensor, the second laser displacement sensor, and the third laser displacement sensor are combined, lasers are emitted to determine the height of three points on the wafer surface, and the wafer attitude can be determined based on the three-point positioning.

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