Multi-size wafer acoustic levitation device for semiconductor applications and attitude measurement system

Abstract

The application discloses a multi-size wafer acoustic levitation device and attitude measurement system for semiconductor application, and belongs to the technical field of semiconductor processing. The device comprises a base and a planetary support, the planetary support is connected with the base, a transducer is installed on the planetary 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 has a gradually changing slope, the diameter of the second boss is smaller than that of the first boss, and the thickness of the second boss is greater than that of the first boss. The transducer transmits vibration to the vibrator, the size and thickness of the first boss and the second boss are adjusted, high-order bending of the vibrator is excited, the surrounding air is compressed to form a regular high-pressure area and a low-pressure area, and the multi-size wafer placed on the vibrator is suspended. The application adopts acoustic levitation to realize multi-size wafer suspension control, avoids scratching of the wafer and the actuator, designs a wafer suspension measurement system, and realizes wafer suspension height and attitude measurement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor processing, in particular to a multi-size wafer acoustic suspension device and attitude measurement system for semiconductor applications. BACKGROUND

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

[0003] Semiconductor processing is an important process in the chip manufacturing field and an important link in high-end equipment manufacturing. Contact friction damage, precision size processing deviation, and residual contamination are common processes and defects in wafer processing. Among them, the processing method (contact type), i.e. the contact between the wafer and the processing equipment actuator, will cause stress deformation and friction damage to the wafer, resulting in contamination and scratches on the wafer surface, damaging the processing precision, affecting the production capacity and yield, and seriously hindering the development of the chip industry, especially advanced chip manufacturing.

[0004] To solve the problems of friction, contamination, and scratches caused by the contact processing method, existing technical means include air suspension, electromagnetic suspension, and temporary backside coating technology. However, these technologies still have problems that have not been solved. Air suspension relies on high-pressure airflow to form a uniform air film between the wafer and the bearing surface, and non-contact support and driving are achieved through pressure balance of the air film. Its stability completely depends on the uniformity and consistency of the air film, which is greatly affected by environmental factors and is difficult to control accurately. Electromagnetic type, since non-magnetic wafers (such as silicon, silicon carbide, gallium nitride, etc. mainstream semiconductor materials) themselves do not have ferromagnetic properties, they cannot directly form force coupling with the magnetic field of the electromagnetic system. The main problems of temporary backside coating in wafer processing are concentrated in warping and scratching, glue / film residue and particles, and weak compatibility of ultra-thin wafers. SUMMARY

[0005] To solve the above problems, the present application provides a multi-size wafer acoustic suspension device and attitude measurement system for semiconductor applications, which uses acoustic suspension to realize multi-size wafer suspension control, avoids wafer and actuator scratches, and designs a wafer suspension measurement system to realize wafer suspension height and pose measurement.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] In a first aspect of the present application, a multi-size wafer acoustic suspension device for semiconductor applications is provided, comprising a base and a planetary support, the planetary support being connected to the base through a support circular tube, a transducer being installed on the planetary support, the top of the transducer being connected to a vibrator;

[0008] The vibrator comprises a first boss and a second boss, the first boss and the second boss are concentrically arranged, the second boss has a tapered slope, and the diameter of the second boss is smaller than the diameter of the first boss, and the thickness of the second boss is greater than the thickness of the first boss;

[0009] The transducer transmits the vibration to the vibrator, by adjusting the size and thickness of the first boss and the second boss, the vibrator is excited to generate high-order bending, and the surrounding air is squeezed to form a regular high-pressure area and a low-pressure area distribution, so that the multiple-size wafers placed on the vibrator are suspended.

[0010] As a further implementation manner, a cylindrical countersunk hole is arranged on the vibrator, a bolt is arranged in the cylindrical countersunk hole, and the bolt is used to connect the transducer and the vibrator.

[0011] As a further implementation manner, when the transducer is applied with high-frequency alternating voltage, the transducer converts the electrical signal into periodic longitudinal vibration through the piezoelectric effect.

[0012] As a further implementation manner, when the vibration is transmitted from the transducer to the vibrator, the longitudinal vibration is converted into bending vibration by the vibrator.

[0013] As a further implementation manner, when the pressure difference between the upper and lower surfaces of the wafer is balanced with the gravity, the wafer reaches a suspended state.

[0014] As a further implementation manner, when the vibrator generates high-order bending, there are multiple high-pressure areas and low-pressure areas, and different sizes of wafers are suspended at corresponding positions.

[0015] As a further implementation manner, by adjusting the size and thickness of the first boss and the second boss, the stiffness of the vibrator is adjusted, which is conducive to exciting the high-order bending of the vibrator.

[0016] As a further implementation manner, by arranging the first boss and the second boss, three steps of different heights are formed on the bottom surface of the vibrator.

[0017] As a further implementation manner, the first step is located in the central region of the vibrator, has the maximum thickness, and performs approximately in-phase plunger movement, the second step is located in the middle region of the vibrator, has a reduced thickness compared with the first step, has a reduced stiffness, is easy to bend, and can excite high-order bending of the vibrator, and the third step is located in the outermost region of the vibrator, has the minimum thickness compared with the first two bosses, has the lowest stiffness, can generate large deformation on the outside of the vibrator, and realizes stress on the outside of the wafer.

[0018] In a second aspect, the application provides a multi-size wafer posture measurement system for semiconductor applications, based on the multi-size wafer acoustic suspension device for semiconductor applications of the first aspect, comprising a first laser displacement sensor, a second laser displacement sensor and a third laser displacement sensor, which are used separately to measure the suspension height of the wafer at different positions, and when the first laser displacement sensor, the second laser displacement sensor and the third laser displacement sensor are combined, the three-point height of the wafer surface is determined by laser emission, and the wafer posture is determined according to the three-point positioning.

[0019] Compared with the prior art, the application has the following beneficial effects:

[0020] The multi-size wafer acoustic suspension device for semiconductor applications and the posture measurement system of the application are designed to solve the problems of friction, contamination and scratching caused by the contact processing mode, and a multi-size wafer acoustic suspension device and measurement system for semiconductor processing are designed, which can induce / excite high-order bending vibration modes of the vibrator through variable stiffness design, and realize the suspension effect of wafers of various sizes. The laser sensor determines the suspension height of the wafer. Based on the three-point positioning principle, the non-contact measurement of the wafer suspension posture can be realized. In addition, the designed multi-size wafer acoustic suspension device and measurement system also have the advantages of small size, high integration, low manufacturing cost and customizable use, and are easy to integrate and apply in wafer manufacturing, processing and transportation processes and links. It can provide a new idea for wafer transmission in semiconductor processing. BRIEF DESCRIPTION OF DRAWINGS

[0021] The drawings accompanying the specification of the application form part of the application and serve to further understand the application. The illustrative embodiments of the application and their description serve to explain the application without forming an improper limitation of the application.

[0022] Figure 1 The structure diagram of the multi-size wafer acoustic suspension device for semiconductor applications of the application is shown.

[0023] Figure 2 The structure diagram of the vibrator of the multi-size wafer acoustic suspension device of the application is shown.

[0024] Figure 3 The schematic diagram of the vibrator mode and suspension principle of the application is shown.

[0025] Figure 4 The schematic diagram of the suspension of wafers of different sizes is shown.

[0026] Figure 5 The structure diagram of the multi-size wafer posture measurement system for semiconductor applications of the application is shown.

[0027] 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

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] 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.

[0030] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0031] Example 1

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] The second boss 53 is located at the center of the vibrator 5, and has a gradually changing slope. The advantages of this design include: 1. The second boss 53 is located at the center region, and the transducer 4 transmits a large amount of energy. The thick boss size can make the vibration phase in the boss range similar, which is close to the plunger movement, thereby forming a large range of high energy and high / low pressure area (depending on the vibration period), which is beneficial to improve the suspension capability. 2. Due to the strong vibration, the larger boss thickness can effectively prevent fatigue failure. At the same time, the gradually changing slope can prevent the force transmitted by the transducer 4 from suddenly changing to the surface of the vibrator 5.

[0037] The first boss 51 is located in the middle region of the vibrator 5, and has a smaller thickness than the second boss 53. Since the small thickness means small stiffness, compared with the position of the second boss 53, this region is more prone to bending.

[0038] Through the setting of the first boss 51 and the second boss 53, three height steps are formed on the bottom surface of the vibrator 5. The first step is located in the center region of the vibrator 5, and has the maximum thickness, which is close to the in-phase plunger movement. The second step is located in the middle region of the vibrator 5, and has a smaller thickness than the first step, and the stiffness is reduced, which is easy to bend and can excite high-order bending through the vibrator 5. The third step is located in the outermost region of the vibrator 5, and has the smallest thickness and the lowest stiffness compared with the first two bosses, which can produce large deformation on the outside of the vibrator 5 to realize the stress on the outside of the wafer 6.

[0039] As shown in Figure 3 The vibrator 5 mode and the suspension principle: when a high-frequency alternating voltage is applied to the transducer 4, the transducer 4 converts the electrical signal into a 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 size of the first boss 51 and the second boss 53, the vibrator 5 can effectively excite high-order bending. Further, under the action of the near field, the vibrator 5 squeezes the surrounding air to form different shapes of sound field, and the shape of the sound field corresponds to the mode one by one. (As shown in Figure 3 When the pressure difference between the upper and lower surfaces of the wafer 6 and the gravity are balanced, the wafer 6 reaches the suspended state.

[0040] The vibrator 5 squeezes the air in different modes to form different shapes of sound field, and the shape of the sound field corresponds to the mode one by one, such as the vibrator 5 is in the plunger vibration mode, that is, the entire vibrator 5 vibrates in phase (at the same time) up and down. With the increase of the size of the wafer 6, the vibration energy increases in a square of the diameter. The existing transducer 4 has limited power and cannot provide the required vibration energy. (The higher the frequency, the higher the vibration energy. In order to suppress bending, the thickness of the vibrator 5 needs to be increased, and the larger the thickness, the greater the mass, and the higher the required vibration energy, which is difficult for the transducer 4 (power element) to provide.)

[0041] When the center plunger motion range is reduced, the larger the wafer 6 size is, the more likely it is to cause the force to deviate from the center of mass range due to the force being concentrated to the center. Therefore, by adjusting the stiffness, high-order bending is excited outside the vibrator 5. In one cycle, the vibrator 5 squeezes the air to form multiple concentric high / low pressure areas. Each high pressure area can provide a support force for the wafer 6, thereby achieving stable suspension of wafers 6 of different diameters.

[0042] Different size wafer 6 suspension schematic diagram is shown in Figure 4 As shown, due to the high-order bending of the vibrator 5, i.e. the vibrator 5 can have multiple high / low pressure areas, different size wafers 6 are placed in the acoustic field, and the wafer 6 can be suspended at the corresponding position. Due to the extremely small air damping, the wafer 6 is most stable when the diameter corresponds to the nodal position of the vibrator 5. The horizontal swing of the wafer 6 caused by the horizontal component of the bending deformation can be effectively avoided. The vibration position can be measured by a laser vibration meter or other instruments.

[0043] When the vibrator 5 is deformed, as shown in Figure 3 Under the excitation of the transducer 4, the vibrator 5 forms, from the inner hole to the outside, in order: in-phase plunger, bending, and large deformation on the outside. The suspension capability can be improved, and the suspension stability of wafers 6 of different sizes can be improved (the force on the outside of the wafer, and the suspension force on the outside is larger).

[0044] Embodiment two

[0045] The embodiment provides a multi-size wafer attitude measurement system for semiconductor applications, based on the multi-size wafer acoustic suspension device for semiconductor applications in embodiment one, including 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 alone to measure the suspension 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, the three-point height of the wafer 6 surface is determined by emitting laser, and the attitude of the wafer 6 is determined according to the three-point positioning.

[0046] The measurement system schematic diagram is shown in Figure 5 The measurement system 7 includes: a first laser displacement sensor 71; a second laser displacement sensor 72; and a third laser displacement sensor 73. The laser displacement sensor is used alone 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, the three-point height of the wafer 6 surface is determined by emitting laser, and the attitude of the wafer is determined according to the three-point positioning.

[0047] The above merely describes the preferred embodiments of the present application and is not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0048] The above merely describes the preferred embodiments of the present application and is not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A multi-size wafer acoustic levitation apparatus for semiconductor applications, characterized by, The device comprises a base and a planet support connected to the base through a supporting circular tube, and a transducer installed on the planet support, the top of the transducer being connected to a vibrator; The vibrator comprises a first boss and a second boss, the first boss and the second boss being concentrically arranged, the second boss having a tapered slope, and the diameter of the second boss being smaller than that of the first boss, and the thickness of the second boss being greater than that of the first boss; The transducer transmits vibration to the vibrator, and by adjusting the size and thickness of the first boss and the second boss, the vibrator is excited to generate high-order bending, and the surrounding air is squeezed to form a regular distribution of high-pressure and low-pressure areas, so that multiple-size wafers placed on the vibrator are suspended.

2. The multi-size wafer acoustic levitation apparatus for semiconductor applications of claim 1, wherein, A cylindrical counterbore is arranged on the vibrator, and a bolt is installed in the cylindrical counterbore, the bolt being used to connect the transducer and the vibrator.

3. The multi-size wafer acoustic levitation apparatus for semiconductor applications of claim 1, wherein, When a high-frequency alternating 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 apparatus for semiconductor applications of claim 1, wherein, 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 apparatus for semiconductor applications as claimed in claim 1, wherein, When the pressure difference between the upper and lower surfaces of the wafer is balanced with the gravity, the wafer reaches a suspended state.

6. The multi-size wafer acoustic levitation apparatus for semiconductor applications of claim 1, wherein, When the vibrator generates high-order bending, there are multiple high-pressure and low-pressure areas, and different-size wafers are suspended at corresponding positions.

7. The multi-size wafer acoustic levitation apparatus for semiconductor applications as claimed in claim 1, wherein, By adjusting the size and thickness of the first boss and the second boss, the stiffness of the vibrator is adjusted, which is conducive to exciting high-order bending of the vibrator.

8. The multi-size wafer acoustic levitation apparatus for semiconductor applications of claim 1, wherein, Through the arrangement of the first boss and the second boss, three steps of different heights are formed on the bottom surface of the vibrator.

9. The multi-size wafer acoustic levitation apparatus for semiconductor applications as claimed in claim 8, wherein, The first step is located in the central region of the vibrator, has the maximum thickness, and moves approximately in phase with the piston, the second step is located in the middle region of the vibrator, has a smaller thickness than the first step, has a lower stiffness, is easy to bend, and can excite high-order bending of the vibrator, and the third step is located in the outermost region of the vibrator, has the smallest thickness and the lowest stiffness compared with the first two bosses, can produce large deformation on the outside of the vibrator, and realizes stress on the outside of the wafer.

10. A multi-size wafer pose measurement system for semiconductor applications, characterized by, Based on the multi-size wafer acoustic suspension device for semiconductor applications according to any one of claims 1-9, a first laser displacement sensor, a second laser displacement sensor, and a third laser displacement sensor are arranged, the three laser displacement sensors are used alone to measure the suspension height of the wafer at different positions, and when the first laser displacement sensor, the second laser displacement sensor, and the third laser displacement sensor are combined, the three-point height of the wafer surface is determined by emitting laser, and the attitude of the wafer is determined according to three-point positioning.

Images