Wafer inspection device and method of inspection thereof

Abstract

The application discloses a wafer detection device and a detection method thereof, and relates to the technical field of wafer detection.The wafer detection device comprises a sealed cavity, a detection host, a stage, an optical detection module, an electron beam detection module and a data processing and storage unit.The sealed cavity, the detection host, the stage, the optical detection module, the electron beam detection module and the data processing and storage unit are arranged, so that the precision and efficiency of wafer detection are improved, and the high-quality detection requirement of wafers in a super-clean room production environment is met.Further, the sealed cavity is arranged, so that external pollution invasion is reduced, and the stability of the super-clean environment is maintained.

Description

Technical Field

[0001] This invention relates to the field of wafer inspection technology, and in particular to a wafer inspection device and its inspection method. Background Technology

[0002] In semiconductor wafer manufacturing, the production environment must be a cleanroom to prevent microparticles from contaminating the wafers and affecting product quality. With the continuous development of semiconductor technology, the requirements for wafer inspection are becoming increasingly stringent, necessitating massive real-time monitoring and data collection to promptly detect defects and anomalies in the production process and ensure product yield.

[0003] Existing monitoring equipment and methods are insufficient to meet the growing demand for real-time monitoring in terms of accuracy, speed and stability, resulting in some defects not being detected in a timely and accurate manner. Moreover, the existing cleanroom space cannot maintain the clean environment well and is easily invaded by external impurities, such as impurities contained in the ultrapure water and special gases used in the wafer manufacturing process. Summary of the Invention

[0004] The purpose of this invention is to provide a wafer inspection device and its inspection method to solve the above-mentioned technical problems.

[0005] The technical solution adopted in this invention is as follows: A wafer inspection apparatus includes a sealed cavity, an inspection host, a stage, an optical inspection module, an electron beam inspection module, and a data processing and storage unit. The stage is disposed inside the sealed cavity, and the upper end of the stage is used to place the wafer. The optical inspection module and the electron beam inspection module are disposed inside the sealed cavity and are located above the stage. The data processing and storage unit and the inspection host are located outside the sealed cavity. The optical inspection module, the electron beam inspection module, and the data processing and storage unit are respectively connected to the inspection host, and the optical inspection module and the electron beam inspection module are respectively connected to the data processing and storage unit.

[0006] Preferably, the system also includes a linear module, which is disposed inside the sealed cavity, and the optical detection module is disposed on the linear module.

[0007] Preferably, the system also includes an air filtration system, a first pipeline, a one-way valve, an intake valve, and a pressure sensor. The air filtration system is located outside the sealed cavity and is connected to the inside of the sealed cavity through the first pipeline. The one-way valve, the intake valve, and the pressure sensor are sequentially arranged on the first pipeline.

[0008] Preferably, the system also includes a second pipeline and an exhaust valve, one end of which is connected to the interior of the sealed cavity, and the exhaust valve is provided on the second pipeline.

[0009] Preferably, the system also includes a gas recovery system, a third pipeline, and a gas supply system. One end of the third pipeline is connected to the upper end of the sealed cavity, and the other end of the third pipeline extends into the sealed cavity and is located above the stage. The gas recovery system and the gas supply system are sequentially arranged on the third pipeline from one end to the other.

[0010] As a further preferred embodiment, the system also includes a gas purification system and a gas storage system, wherein the gas purification system is disposed between the gas recovery system and the gas supply system, and the gas storage system is disposed between the gas purification system and the gas supply system.

[0011] Preferably, the system also includes a fourth pipeline, a fifth pipeline, an ultrapure water supply system, and an ultrapure water recycling system. One end of the fourth pipeline is connected to the lower end of the sealed cavity, and the other end of the fourth pipeline is connected to the ultrapure water recycling system. The ultrapure water recycling system is connected to the ultrapure water supply system, and the ultrapure water supply system is connected to the interior of the sealed cavity through the fifth pipeline.

[0012] A detection method based on the wafer inspection apparatus of claim 1 includes the following steps: S1. Place the wafer on the top of the stage and adjust the position of the wafer to make the wafer coaxial with the stage, and input the detection command through the detection host. S2. The optical inspection module first scans and images the wafer surface, acquires macroscopic image data of the wafer surface, and transmits the data to the data processing and storage unit. S3, the data processing and storage unit preprocesses the image data acquired by the optical inspection module, uses image recognition algorithms to detect macroscopic defects on the wafer surface, and marks the location and type of defects; S4. Then, the electron beam detection module performs microstructure detection on the defect area marked by the optical detection module and a randomly selected area, emits an electron beam and collects the reflected electron signals, and transmits the signal data to the data processing and storage unit. S5, the data processing and storage unit analyzes the signal data collected by the electron beam detection module, reconstructs the wafer microstructure image, and further determines the microscopic features and causes of defects; S6. The data processing and storage unit summarizes the test results, generates a detailed test report, and stores it in the database. At the same time, it feeds back the test results to the test host.

[0013] The above technical solution has the following advantages or beneficial effects: (1) In this invention, by setting up a sealed cavity, a detection host, a stage, an optical detection module, an electron beam detection module and a data processing and storage unit, the accuracy and efficiency of wafer detection can be improved, meeting the high-quality detection requirements of wafers in a cleanroom production environment; moreover, the setting of the sealed cavity can reduce the intrusion of external contaminants and maintain the stability of the cleanroom environment.

[0014] (2) In this invention, by setting up an air filtration system and an ultrapure water recycling system, impurities in the air and water can be prevented from entering the sealed cavity and polluting the internal environment of the sealed cavity; by setting up an ultrapure water recycling system and a gas recovery system, energy utilization can be improved and energy consumption can be saved. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the wafer inspection device in this invention; Figure 2 This is a schematic diagram of the wafer inspection device in this invention; Figure 3 This is a flowchart of the detection method based on a wafer inspection device in this invention.

[0016] In the diagram: 1. Sealed cavity; 2. Stage; 3. Wafer; 4. Slide rail; 5. Optical inspection module; 6. Electron beam inspection module; 7. Temperature sensor; 8. Transparent window; 9. Air filtration system; 10. First pipeline; 11. One-way valve; 12. Inlet valve; 13. Pressure sensor; 14. Second pipeline; 15. Exhaust valve; 16. Third pipeline; 17. Gas recovery system; 18. Gas purification system; 19. Gas storage system; 20. Gas supply system; 21. Ultrapure water supply system; 22. Ultrapure water recycling system; 23. Fourth pipeline; 24. Fifth pipeline. Detailed Implementation

[0017] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] In the description of this invention, it should be noted that terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, terms such as "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] Please see Figures 1 to 3The diagram illustrates a preferred embodiment of a wafer inspection apparatus, comprising a sealed cavity 1, an inspection host, a stage 2, an optical inspection module 5, an electron beam inspection module 6, and a data processing and storage unit. The stage 2 is housed inside the sealed cavity 1, with its upper end used to place a wafer 3. The optical inspection module 5 and electron beam inspection module 6 are located above the stage 2 within the sealed cavity 1. The data processing and storage unit and the inspection host are located outside the sealed cavity 1. The optical inspection module 5, electron beam inspection module 6, and data processing and storage unit are connected to the inspection host, and the optical inspection module 5 and electron beam inspection module 6 are connected to the data processing and storage unit. In this embodiment, the inspection host can be mounted on an external operating platform, connected to the optical inspection module 5, electron beam inspection module 6, and data processing and storage unit via data cables. This facilitates signal transmission, enabling real-time reception of data collected by each inspection module and the sending of control commands. The inspection host is an industrial computer with a human-machine interface, allowing operators to set parameters, control processes, and query results. The optical inspection module 5 employs a high-resolution microscope and a high-speed image acquisition system to rapidly image the surface of wafer 3 for detecting macroscopic defects. The electron beam inspection module 6 is used for microstructure inspection of wafer 3, analyzing its microscopic features by emitting an electron beam and collecting reflected electron signals. The data processing and storage unit is connected to the optical inspection module 5 and the electron beam inspection module 6 to process, analyze, and store the acquired image and electron signal data in real time. The sealed cavity 1 provides an ultra-clean working environment.

[0021] The optical inspection module 5 may include a high-resolution microscope and a high-speed image acquisition card. The high-resolution microscope can provide high-contrast and high-resolution images. Furthermore, a linear module is disposed inside the sealed cavity 1, and the optical inspection module 5 is mounted on the linear module. The linear module drives the optical inspection module 5 to move, facilitating rapid scanning and imaging of the wafer 3 surface.

[0022] In this embodiment, the electron beam detection module 6 can be a dual-beam electron microscope equipped with a field emission electron gun, which can emit a continuously adjustable electron beam.

[0023] In this embodiment, a transparent window 8 is provided on one side of the sealed cavity 1 for observing the internal condition of the sealed cavity 1. The transparent window 8 can be opened for easy placement or removal of the wafer 3. The sealed cavity 1 is made of aluminum alloy, and its inner wall is anodized to increase its hardness and corrosion resistance. Furthermore, an anti-particle adsorption coating is applied to the inner wall of the sealed cavity 1, making it difficult for particles to adhere to its surface and effectively reducing the adsorption and accumulation of dust, impurities, and other particles on the inner wall of the sealed cavity 1.

[0024] Furthermore, as a preferred embodiment, it also includes an air filtration system 9, a first pipeline 10, a one-way valve 11, an intake valve 12, and a pressure sensor 13. The air filtration system 9 is located outside the sealed cavity 1 and is connected to the inside of the sealed cavity 1 through the first pipeline 10. The one-way valve 11, the intake valve 12, and the pressure sensor 13 are sequentially arranged on the first pipeline 10. In this embodiment, the air filtration system 9 integrates a pre-filter, a medium-efficiency filter, and a high-efficiency filter. The pre-filter can filter out particles with a diameter greater than 5 μm, the medium-efficiency filter can filter out particles with a diameter greater than 1 μm, and the high-efficiency filter can filter out particles with a diameter greater than 0.01 μm. By setting up the air filtration system 9, impurities inside the air can be removed, preventing impurities from entering the sealed cavity 1. The one-way valve 11 can prevent air backflow inside the sealed cavity 1, and the intake valve 12 can control the flow rate of the incoming gas, so as to control the air pressure inside the sealed cavity 1 and keep the sealed cavity 1 in a positive pressure state. The air pressure sensor 13 can detect the air pressure inside the sealed cavity 1.

[0025] In this embodiment, the intake valve 12 and the air pressure sensor 13 can be connected to an external controller.

[0026] Furthermore, as a preferred embodiment, it also includes a second pipeline 14 and an exhaust valve 15. One end of the second pipeline 14 is connected to the interior of the sealed cavity 1, and the exhaust valve 15 is provided on the second pipeline 14. The exhaust valve 15 is used to control the discharge of gas inside the sealed cavity 1 and is connected to an external controller. By controlling the inlet valve 12 and the exhaust valve 15, it is easy to control the gas pressure inside the sealed cavity 1, so that the positive pressure inside the sealed cavity 1 is maintained at 5-10 Pa higher than the external environment. Both the inlet valve 12 and the exhaust valve 15 are solenoid valves.

[0027] In this embodiment, a temperature sensor 7 is provided on the inner wall of the sealed cavity 1 to detect the temperature inside the sealed cavity 1.

[0028] Furthermore, as a preferred embodiment, the system also includes a gas recovery system 17, a third pipeline 16, and a gas supply system 20. One end of the third pipeline 16 is connected to the upper end of the sealed cavity 1, and the other end of the third pipeline 16 extends into the sealed cavity 1 and is located above the stage 2. The gas recovery system 17 and the gas supply system 20 are sequentially arranged on the third pipeline 16 from one end to the other. A gas purification system 18 is arranged between the gas recovery system 17 and the gas supply system 20, and a gas storage system 19 is arranged between the gas purification system 18 and the gas supply system 20. The gas recovery system 17 has a gas sensor for monitoring the composition and concentration of special gases (such as nitrogen) in the emitted gas. When unreacted special gases are detected, the gas recovery system 17 collects them and sends them to the purification system. The gas purification system 18 can purify the special gases using adsorption, condensation, and membrane separation methods, and can also remove impurities from the gas to ensure that the purified special gases meet the standards for use. The purified special gas is stored in the gas storage system. A control valve is installed on the pipeline between the gas storage system and the gas supply system 20 to control the purified special gas entering the gas supply system 20 and being transported by the gas supply system 20 to the sealed cavity 1. This can effectively improve the utilization rate of the special gas and save energy.

[0029] Furthermore, as a preferred embodiment, the system also includes a fourth pipeline 23, a fifth pipeline 24, an ultrapure water supply system 21, and an ultrapure water recycling system 22. One end of the fourth pipeline 23 is connected to the lower end of the sealed cavity 1, and the other end of the fourth pipeline 23 is connected to the ultrapure water recycling system 22. The ultrapure water recycling system 22 is connected to the ultrapure water supply system 21, and the ultrapure water supply system 21 is connected to the interior of the sealed cavity 1 through the fifth pipeline 24. The ultrapure water supply system 21 is used to supply ultrapure water to the interior of the sealed cavity 1, and the ultrapure water recycling system 22 is used to recycle the ultrapure water. The ultrapure water recycling system 22 includes a water quality analyzer to detect the water quality parameters of the ultrapure water, such as resistivity and particle content. The ultrapure water recycling system 22 includes a pretreatment unit, a reverse osmosis unit, an ion exchange unit, and a disinfection unit. When used ultrapure water enters the system, it first passes through the pretreatment unit to remove large particulate impurities and organic matter. Then, it enters the reverse osmosis and ion exchange units to remove dissolved salts and ionic impurities. Finally, it passes through the disinfection unit to kill bacteria. The ultrapure water then passes through a water quality analyzer to determine if it meets the standards for reuse.

[0030] Based on the above embodiments, this invention also discloses a detection method based on a wafer 3 inspection device, comprising the following steps: S1. Place the wafer 3 on the upper end of the stage 2 and correct the position of the wafer 3 so that the wafer 3 is coaxial with the stage 2, and input the detection command through the detection host. S2, the optical inspection module 5 first scans and images the surface of wafer 3, acquires macroscopic image data of the surface of wafer 3, and transmits the data to the data processing and storage unit; S3, the data processing and storage unit preprocesses the image data acquired by the optical inspection module 5, uses image recognition algorithms to detect macroscopic defects on the surface of wafer 3, and marks the location and type of defects; S4. Then, the electron beam detection module 6 performs microstructure detection on the defect area marked by the optical detection module 5 and a randomly selected part of the area, emits an electron beam and collects the reflected electron signal, and transmits the signal data to the data processing and storage unit. S5, the data processing and storage unit analyzes the signal data collected by the electron beam detection module 6, reconstructs the microstructure image of wafer 3, and further determines the microscopic features and causes of defects; S6. The data processing and storage unit summarizes the test results, generates a detailed test report, and stores it in the database. At the same time, it feeds back the test results to the test host.

[0031] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A wafer inspection device, characterized in that, The device includes a sealed cavity, a detection host, a stage, an optical detection module, an electron beam detection module, and a data processing and storage unit. The stage is disposed inside the sealed cavity, with its upper end used to place a wafer. The optical detection module and the electron beam detection module are disposed inside the sealed cavity and located above the stage. The data processing and storage unit and the detection host are located outside the sealed cavity. The optical detection module, the electron beam detection module, and the data processing and storage unit are respectively connected to the detection host, and the optical detection module and the electron beam detection module are respectively connected to the data processing and storage unit.

2. The wafer inspection apparatus as described in claim 1, characterized in that, It also includes a linear module, which is disposed inside the sealed cavity, and the optical detection module is disposed on the linear module.

3. The wafer inspection apparatus as described in claim 1, characterized in that, It also includes an air filtration system, a first pipeline, a one-way valve, an intake valve, and a pressure sensor. The air filtration system is located outside the sealed cavity and is connected to the inside of the sealed cavity through the first pipeline. The one-way valve, the intake valve, and the pressure sensor are sequentially arranged on the first pipeline.

4. The wafer inspection apparatus as described in claim 1, characterized in that, It also includes a second pipeline and an exhaust valve. One end of the second pipeline is connected to the inside of the sealed cavity, and the exhaust valve is provided on the second pipeline.

5. The wafer inspection apparatus as described in claim 1, characterized in that, It also includes a gas recovery system, a third pipeline and a gas supply system. One end of the third pipeline is connected to the upper end of the sealed cavity, and the other end of the third pipeline extends into the sealed cavity and is located above the stage. The gas recovery system and the gas supply system are sequentially arranged on the third pipeline from one end to the other.

6. The wafer inspection apparatus as described in claim 5, characterized in that, It also includes a gas purification system and a gas storage system. The gas purification system is provided between the gas recovery system and the gas supply system, and the gas storage system is provided between the gas purification system and the gas supply system.

7. The wafer inspection apparatus as described in claim 1, characterized in that, It also includes a fourth pipeline, a fifth pipeline, an ultrapure water supply system, and an ultrapure water recycling system. One end of the fourth pipeline is connected to the lower end of the sealed cavity, and the other end of the fourth pipeline is connected to the ultrapure water recycling system. The ultrapure water recycling system is connected to the ultrapure water supply system, and the ultrapure water supply system is connected to the interior of the sealed cavity through the fifth pipeline.

8. A detection method based on the wafer inspection apparatus of claim 1, characterized in that, The following steps are included: S1. Place the wafer on the top of the stage and adjust the position of the wafer to make the wafer coaxial with the stage, and input the detection command through the detection host. S2. The optical inspection module first scans and images the wafer surface, acquires macroscopic image data of the wafer surface, and transmits the data to the data processing and storage unit. S3, the data processing and storage unit preprocesses the image data acquired by the optical inspection module, uses image recognition algorithms to detect macroscopic defects on the wafer surface, and marks the location and type of defects; S4. Then, the electron beam detection module performs microstructure detection on the defect area marked by the optical detection module and a randomly selected area, emits an electron beam and collects the reflected electron signals, and transmits the signal data to the data processing and storage unit. S5, the data processing and storage unit analyzes the signal data collected by the electron beam detection module, reconstructs the wafer microstructure image, and further determines the microscopic features and causes of defects; S6. The data processing and storage unit summarizes the test results, generates a detailed test report, and stores it in the database. At the same time, it feeds back the test results to the test host.

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