Film thickness measuring device

Abstract

The utility model provides a film thickness measuring device. The measuring device comprises a carrying platform and at least one measuring unit, the carrying table is used for carrying a sample to be detected; the measuring unit comprises two mechanical arm assemblies, each mechanical arm assembly comprises a base, a first joint, a first mechanical arm, a second joint and a second mechanical arm which are connected in sequence, and the two mechanical arm assemblies are arranged on the two sides of the carrying table through the bases respectively; the lighting unit is arranged on a second mechanical arm of one mechanical arm assembly and is used for emitting detection light to the surface of the sample to be detected; the detection unit is arranged on the second mechanical arm of the other mechanical arm assembly and comprises a receiver and a spectrum analyzer, the receiver is used for receiving reflected light reflected from the surface of the sample to be detected, and the spectrum analyzer is used for carrying out spectrum analysis on the reflected light received by the receiver. The measuring device provided by the utility model greatly improves the efficiency of measuring the thickness of the multi-point film layer of the sample.

Description

Technical Field

[0001] The utility model relates to the technical field of testing equipment, and in particular to a film thickness measuring device. Background Art

[0002] When measuring the film thickness by a metrology tool, generally, light from a light source passes through a polarizer to leave polarized light. The polarized light is reflected on the surface of the wafer to form elliptically polarized light. The elliptically polarized light passes through an analyzer and is then received by a spectrometer to obtain a spectral signal. A computer uses a model to fit with the spectral signal. When the fitting degree between the two approaches 1, the parameters obtained by the model are the parameters of this wafer.

[0003] Parameters of multiple points on the surface of a single wafer need to be measured and averaged as the overall parameters of the wafer surface. Therefore, the light from the light source needs to irradiate different positions on the wafer surface. There are three supports under the wafer to hold up the wafer, and the lower support is a movable chassis. The positions of the light source and the light receiver in the tool are fixed, and the measurement positions are fixed relative to the tool. When different points on the wafer need to be measured, the chassis support drives the wafer to move to the corresponding position, and the point to be measured is placed at the light irradiation position of the light source.

[0004] When there are many points to be measured on the wafer or the distance between the points is large, the time spent on the movement of the chassis is more, resulting in a longer measurement time. Taking a control wafer as an example, 49 points need to be measured for the control wafer measurement, including the wafer center and four concentric circles with gradually increasing radii. The metrology tool starts from the wafer center and then measures the four concentric circles counterclockwise gradually outwards. According to statistics, the time spent on measuring 49 points for a control wafer is about 6 minutes. Most tools need to measure more than 10 control wafers for a complete monitoring. Only in this measurement step, it will take one to two hours. Therefore, it is necessary to develop an efficient and flexible film thickness measuring device.

[0005] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present utility model. Therefore, it may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Utility Model

[0006] Aiming at the problems in the prior art, the purpose of the present utility model is to provide a film thickness measuring device, which greatly improves the efficiency when measuring the film thickness at multiple points of a sample.

[0007] The present utility model provides a film thickness measuring device, including a stage and at least one measuring unit;

[0008] The stage is used for carrying a sample to be detected;

[0009] The measuring unit includes:

[0010] Two robotic arm assemblies, each robotic arm assembly including a base, a first joint, a first robotic arm, a second joint, and a second robotic arm connected in sequence, and the two robotic arm assemblies being respectively disposed on both sides of the stage through the bases;

[0011] A lighting unit, disposed on the second robotic arm of one robotic arm assembly, for emitting detection light to the surface of the sample to be detected;

[0012] A detection unit, disposed on the second robotic arm of the other robotic arm assembly, including a receiver and a spectral analyzer, the receiver being used for receiving the reflected light reflected from the surface of the sample to be detected, and the spectral analyzer being used for performing spectral analysis on the reflected light received by the receiver.

[0013] According to some embodiments of the present invention, the lighting unit includes a light source and a polarizer, and the polarizer is disposed between the light source and the stage.

[0014] According to some embodiments of the present invention, the detection unit further includes an analyzer, and the analyzer is disposed between the receiver and the stage.

[0015] According to some embodiments of the present invention, a moving unit is disposed on the second robotic arm, and the moving unit is connected to the lighting unit and / or the detection unit for controlling the movement of the lighting unit and / or the detection unit.

[0016] According to some embodiments of the present invention, the moving unit is a slide rail, and the slide rail is disposed along the extending direction of the second robotic arm.

[0017] According to some embodiments of the present invention, the first joint and / or the second joint is driven by a motor.

[0018] According to some embodiments of the present invention, a control unit is further included for controlling the rotation of the motor.

[0019] According to some embodiments of the present invention, the stage is movable within a plane.

[0020] According to some embodiments of the present invention, the stage is liftable.

[0021] According to some embodiments of the present invention, the spectral analyzer is provided with a communication module for sending the detection data of the spectral analyzer to a detection terminal.

[0022] By separately disposing the lighting unit and the detection unit on two robotic arm assemblies, the present invention can flexibly measure the thickness of each site on the wafer through the movement of the robotic arm assemblies, greatly improving the efficiency of multi-site thickness measurement. Description of the Drawings

[0023] Other features, objects, and advantages of the present utility model will become more apparent from the following detailed description of non-limiting embodiments read in conjunction with the accompanying drawings.

[0024] Figure 1 Schematic structural diagram of a film thickness measuring device according to an embodiment of the present utility model;

[0025] Figures 2 to 4 Connection structure diagrams of the second joint of the film thickness measuring device according to an embodiment of the present utility model respectively; and

[0026] Figure 5 Top view of the film thickness measuring device according to an embodiment of the present utility model during measurement. Detailed Description of the Embodiments

[0027] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The embodiments described below with reference to the accompanying drawings are exemplary only for explaining the present utility model and should not be construed as limiting the present utility model. Identical reference numerals in the figures denote identical or similar structures, and thus their repetitive description will be omitted.

[0028] In the description of the present utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality of" means two or more unless otherwise specifically defined.

[0029] In the description of the present utility model, it should be noted that unless otherwise clearly defined and limited, the terms "mounted", "connected", and "coupled" should be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection, or a connection capable of mutual communication; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0030] The following disclosure provides many different embodiments or examples for implementing different structures of the present utility model. To simplify the disclosure of the present utility model, components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present utility model. In addition, the present utility model may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between various embodiments and / or settings discussed. In addition, the present utility model provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0031] As described above, it takes a lot of time for the metrology tool to measure the measurement points. Approximately 30% - 50% of the time in a monitoring process is spent on the measurement step. If there are multiple points to be measured simultaneously, the long queue will take a lot of time and may delay the goods passing.

[0032] In view of the above technical problems, the present utility model provides a film thickness measuring device. The measuring device includes a stage and at least one measuring unit; the stage is used for carrying a sample to be detected; the measuring unit includes: two robotic arm assemblies, each robotic arm assembly includes a base, a first joint, a first robotic arm, a second joint and a second robotic arm connected in sequence, and the two robotic arm assemblies are respectively arranged on both sides of the stage through the base; an illumination unit, arranged on the second robotic arm of one robotic arm assembly, for emitting detection light to the surface of the sample to be detected; a detection unit, arranged on the second robotic arm of the other robotic arm assembly, including a receiver and a spectral analyzer, the receiver is used for receiving the reflected light reflected from the surface of the sample to be detected, and the spectral analyzer is used for performing spectral analysis on the reflected light received by the receiver.

[0033] The illumination unit and the detection unit of the film thickness measuring device of the present utility model are respectively arranged on two robotic arm assemblies. By moving the robotic arm assemblies, the thickness of each site on the wafer can be measured flexibly, greatly improving the efficiency of multi-point thickness measurement.

[0034] The structure of the film thickness measuring device of the present utility model will be further described below in conjunction with the accompanying drawings and specific embodiments. It can be understood that each specific embodiment does not limit the protection scope of the present utility model.

[0035] Figure 1 FIG. is a schematic structural diagram of a film thickness measuring device according to an embodiment of the present utility model. Specifically, the film thickness measuring device includes a stage 1 and at least one measuring unit;

[0036] The stage 1 is used for carrying a sample 9 to be detected;

[0037] The measurement unit includes:

[0038] Two robotic arm assemblies, each robotic arm assembly including a base 21a / 21b, a first joint 22a / 22b, a first robotic arm 23a / 23b, a second joint 24a / 24b, and a second robotic arm 25a / 25b connected in sequence. The two robotic arm assemblies are respectively disposed on both sides of the stage through the bases 21a / 21b; that is, the base 21a, the first joint 22a, the first robotic arm 23a, the second joint 24a, and the second robotic arm 25a form a robotic arm assembly on one side, and the base 21b, the first joint 22b, the first robotic arm 23b, the second joint 24b, and the second robotic arm 25b form a robotic arm assembly on the other side. The bases 21a / 21b can be fixedly connected to the measurement platform respectively. The measurement platform can be a chamber. At this time, the stage can be disposed inside the chamber, and the bases can be fixedly connected to the side walls on both sides of the chamber.

[0039] An illumination unit 3, disposed on the second robotic arm 25a / 25b of one of the robotic arm assemblies, for emitting detection light to the surface of the sample to be detected; the illumination unit 3 can include a light source, and the light source can be a xenon light source that emits light by discharging high-pressure or ultra-high-pressure xenon gas, etc.

[0040] A detection unit 4, disposed on the second robotic arm 25b / 25a of the other robotic arm assembly, including a receiver and a spectral analyzer. The receiver is used to receive the reflected light reflected from the surface of the sample to be detected, and the spectral analyzer is used to perform spectral analysis on the reflected light received by the receiver. The spectral analyzer can adopt an existing commercially available spectral analyzer.

[0041] When using the measurement device of the present utility model, place the sample 9 to be detected on the stage 1. By moving the two robotic arm assemblies, the illumination unit 3 and the detection unit 4 are set at opposite positions on both sides of the sample 9 to be detected (such as a wafer). The light source of the illumination unit 3 irradiates a certain measurement site of the sample 9 to be detected on the stage 1. The receiver of the detection unit 4 receives the reflected light reflected from the sample 9 to be detected, and the spectral analyzer of the detection unit 4 performs spectral analysis. The measurement range of this film thickness measuring device is relatively wide, and it can measure the film thickness from 0.1 micrometer to 20 millimeters, and can also measure the thickness of film layers of various materials, such as metal thin films, plastic thin films, polymer thin films, etc. It can be applied not only to the measurement of the film thickness on the surface of a wafer, but also to the measurement of the film thickness deposited on the surface of other products.

[0042] The lighting unit and the detection unit of the film thickness measuring device of the present utility model are respectively arranged on two robotic arm assemblies. The positions of the first robotic arm 23a / 23b and the second robotic arm 25a / 25b can be controlled through the first joint 22a / 22b and the second joint 24a / 24b, so as to control the positions of the lighting unit 3 and the detection unit 4 arranged on the second robotic arm 25a / 25b. Thus, the thickness of the film at any point on the sample to be detected can be flexibly measured, providing flexibility and efficiency in measurement, and is particularly suitable for detecting the film thickness at random points.

[0043] In some embodiments, in addition to the light source, the lighting unit 3 further includes a polarizer, which is arranged between the light source and the stage 1. The polarizer converts the light beam emitted by the light source into linearly polarized light with a single vibration direction. Correspondingly, the detection unit further includes an analyzer, which is arranged between the receiver and the stage. After the linearly polarized light is reflected by the surface of the sample to be detected or transmitted through the film layer, its polarization state will change. This change contains the optical and geometric information of the sample. The polarization state of the reflected or transmitted light is detected by the analyzer, receiver and spectral analyzer of the detection unit, so as to calculate optical parameters such as the refractive index and thickness of the film layer of the sample to be detected.

[0044] In some embodiments, a moving unit is arranged on the second robotic arm, such as Figure 1 As shown, a moving unit 251a is arranged on the second robotic arm 25a, and a moving unit 251b is arranged on the second robotic arm 25b. Among them, the moving unit 251a is connected to the lighting unit 3 and controls the movement of the lighting unit 3, and the moving unit 251b is connected to the detection unit 4 and controls the movement of the detection unit 4, or vice versa, that is, the moving unit 251a is connected to the detection unit 4 and controls the movement of the detection unit 4, and the moving unit 251b is connected to the lighting unit 3 and controls the movement of the lighting unit 3. For example, the moving unit 251a / 251b can be a slide rail, and the slide rail is arranged along the extension direction of the second robotic arm 25a / 25b.

[0045] The structure of the first joint or the second joint of the present disclosure will be described below taking the second joint as an example. Figures 2 to 4 Respectively are the connection structure diagrams of the second joint of the film thickness measuring device according to an embodiment of the present utility model. The second joint 24a can be a turntable, and the turntable is rotatably connected to the first robotic arm 23a. The rotation of the turntable drives the second robotic arm 25a to rotate relative to the end plane of the first robotic arm 23a where the turntable is arranged. See the top view in Figure 2 A bearing seat (not shown in the figure) and a bearing 241a can be arranged in the turntable. This section of the second robotic arm 25a is rotatably connected to the bearing, and this connection enables the second robotic arm 25a to rotate in a plane perpendicular to the rotation plane of the turntable. SeeFigure 3 Similarly, the first joint 22a / 22b and the second joint 24b can adopt the above structure. In the above structure, the bearing can be connected to the output shaft of the motor, and the motor is used to control the rotation of the second mechanical arm 25a in the vertical plane.

[0046] In some other embodiments, the first joint may include a concave portion and a spherical joint; the concave portion is connected to the non-fixed end of the base, the spherical joint is connected to an end of the first mechanical arm away from the second mechanical arm, the spherical joint is accommodated in the concave portion, and the spherical joint and the concave portion are connected to form a concave-convex connection member by at least one bolt. The concave-convex connection member can enable the first mechanical arm to perform circumferential motion relative to the base.

[0047] The second joint 24a / 24b may include a transmission wheel disposed at one end where the first mechanical arm is connected to the second mechanical arm, a first gear disposed at one end of the transmission wheel, and a second gear disposed at one end where the second mechanical arm is connected to the first mechanical arm, the second gear meshes with the first gear, and the rotation of the transmission wheel drives the rotation of the first gear, the second gear, and the second mechanical arm connected to the second gear. At the same time, the other end of the transmission wheel may be connected to the output shaft of the motor, and the rotation of the transmission wheel is driven by the motor. Further, the measuring device also includes a control unit for controlling the rotation of the motor.

[0048] In some other embodiments, the first joint 22a / 22b may include a transmission wheel arranged at one end of the base connected to the first mechanical arm, a first gear arranged at one end of the transmission wheel, and a second gear arranged at one end of the first mechanical arm connected to the base, the second gear is meshed with the first gear, and the rotation of the transmission wheel drives the rotation of the first gear, the second gear and the first mechanical arm connected to the second gear, and the second joint may adopt a structure of a concave-convex connector. Similarly, the other end of the transmission wheel of the first joint may be connected to the output shaft of the motor, and the rotation of the transmission wheel is driven by the motor. Further, the measuring device also includes a control unit for controlling the rotation of the motor.

[0049] Through the cooperation of the first joint 22a / 22b and the second joint 24a / 24b, the movement of the second mechanical arm connected to the lighting unit 3 or the detection unit 4 in the horizontal and vertical directions can be accurately controlled. Figure 5 The top view of the film thickness measuring device according to one embodiment of the present invention during measurement is shown.

[0050] The carrier 1 can be movable within a plane and can also be raised and lowered. When certain points of the sample to be tested are beyond the movement range of the two robotic arm assemblies, the movement of the carrier within the plane and in the direction perpendicular to the plane can serve as a supplement to further expand the measurement range of the measuring device.

[0051] The spectral analyzer is provided with a communication module for sending the detection data of the spectral analyzer to a detection terminal. The communication module can be a wireless communication module or a wired communication module, and the detection terminal can be a computer, a mobile phone, a work recorder, etc. used by the measurement personnel. Through the setting of the communication module, the measured data can be conveniently obtained.

[0052] It should be noted that the measuring device of the present invention may include multiple measuring units. The multiple measuring units can measure multiple points simultaneously, improving the measurement efficiency and reducing the measurement cost. At the same time, by setting the first robotic arm and the second robotic arm at different positions, a larger measurement range can be covered, expanding the applicable range of the measuring device.

[0053] In addition, it should be pointed out that in the technical solution of the film thickness measuring device of the present invention, each of the included functional modules and module units can correspond to specific hardware circuits in an integrated circuit structure. Therefore, it only involves the improvement of specific hardware circuits. The hardware part is not merely a carrier for executing control software or computer programs. Therefore, solving the corresponding technical problems and obtaining the corresponding technical effects do not involve the application of any control software or computer programs. That is to say, the present invention can solve the technical problems to be solved and obtain the corresponding technical effects only by using the improvements in the hardware circuit structures involved in these modules and units, without the need to assist with specific control software or computer programs to achieve the corresponding functions.

[0054] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0055] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, which should all be regarded as belonging to the protection scope of the present invention.

Claims

1. A film thickness measuring device, characterized in that, Comprising a stage and at least one measuring unit; The stage is used for carrying the sample to be detected; The measuring unit includes: Two robotic arm assemblies, each robotic arm assembly including a base, a first joint, a first robotic arm, a second joint and a second robotic arm connected in sequence, and the two robotic arm assemblies are respectively arranged on both sides of the stage through the bases; An illumination unit, arranged on the second robotic arm of one robotic arm assembly, for emitting detection light to the surface of the sample to be detected; A detection unit, arranged on the second robotic arm of the other robotic arm assembly, including a receiver and a spectral analyzer, the receiver is used for receiving the reflected light reflected from the surface of the sample to be detected, and the spectral analyzer is used for performing spectral analysis on the reflected light received by the receiver.

2. The film thickness measuring device according to claim 1, wherein The illumination unit includes a light source and a polarizer, and the polarizer is arranged between the light source and the stage.

3. The film thickness measuring device according to claim 1, characterized in that, The detection unit further includes an analyzer, and the analyzer is arranged between the receiver and the stage.

4. The film thickness measuring device according to claim 1, characterized in that, A moving unit is arranged on the second robotic arm, and the moving unit is connected to the illumination unit and / or the detection unit, for controlling the movement of the illumination unit and / or the detection unit.

5. The film thickness measuring device according to claim 4, characterized in that, The moving unit is a slide rail, and the slide rail is arranged along the extending direction of the second robotic arm.

6. The film thickness measuring device according to claim 1, characterized in that, The first joint and / or the second joint is driven by a motor.

7. The film thickness measuring device according to claim 6, characterized in that, It further includes a control unit for controlling the rotation of the motor.

8. The film thickness measuring device according to claim 1, characterized in that, The stage can move within a plane.

9. The film thickness measuring device according to claim 1, characterized in that, The stage can be lifted.

10. The film thickness measuring device according to claim 1, characterized in that, The spectral analyzer is provided with a communication module for sending the detection data of the spectral analyzer to a detection terminal.

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