Device for measuring thickness and refractive index of thin film

Abstract

The utility model relates to a device for measuring the thickness and refractive index of a film, which comprises an object placing table, the object placing table is provided with a clamping assembly used for fixing a triangular prism and an air cylinder used for enabling a film sample to be tightly attached to the surface of the triangular prism, the object placing table is internally provided with an air passage, and the air passage is used for communicating air source equipment with the air cylinder; a rotor of the hollow shaft motor is fixed with the object placing table, and the hollow shaft motor is used for driving the object placing table to rotate; one end of the air pipe penetrates through the hollow shaft motor to be communicated with the air channel, and the other end of the air pipe is in ventilation communication with air source equipment; wherein the air pipe is rotationally connected with the storage table, or the air pipe is rotationally connected with an air valve of air source equipment. According to the device for measuring the thickness and the refractive index of the thin film, disclosed by the utility model, the measurement precision and reliability are improved; and meanwhile, the integration level is improved, so that the overall structure of the measuring device is more compact.

Description

Technical Field

[0001] The utility model relates to the technical field of optical measurement, in particular to a device for measuring film thickness and refractive index. Background Art

[0002] Thin films are widely used in many fields such as optical engineering, mechanical engineering, bioengineering, aerospace engineering, and medical engineering. Film thickness is not only one of the key parameters in film production, but also determines the performance of films in mechanical, electromagnetic, and optical applications. Therefore, accurate measurement of film thickness is an important part of film production and application.

[0003] At present, there are many methods to measure film thickness and its optical constants (such as refractive index), including ellipsometry, interferometry, prism coupling, spectroscopy, etc. Among them, the prism coupling method stands out among many measurement technologies due to its high precision and non-destructive characteristics, and is widely used in the measurement of different types of films.

[0004] The prism coupling method uses the optical coupling phenomenon between the prism and the film to obtain the optical parameters of the film (such as thickness and refractive index) by measuring the change in the intensity of the reflected or transmitted light of the incident light at the interface between the prism and the film. The specific operation steps include: 1. Fit the film sample tightly to the surface of the high refractive index prism so that the light is coupled into the film through the prism; 2. Use a laser beam of a specific wavelength to be incident on the film through the prism at a predetermined incident angle; 3. Change the incident angle of the laser. At certain specific angles, the incident light will reach the lowest reflectivity (coupling angle) due to the light coupling into the film. At this time, the light energy is coupled into the film to the maximum extent; 4. By accurately measuring the data of these coupling angles, record the intensity changes of the reflected and transmitted light; 5. Apply mathematical models and algorithms to calculate the thickness and refractive index of the film based on the intensity data of the reflected and transmitted light.

[0005] In the prior art, the measurement device using the prism coupling method generally uses a cylinder to make the film sample fit tightly on the prism surface, and uses a motor to drive the prism, the film sample and the cylinder to rotate together to change the incident angle of the laser, wherein the cylinder is connected to the air source device through an air pipe. However, the rotation of the cylinder causes the swing of the air pipe to become an interference factor in the measurement, thereby reducing the measurement accuracy; in addition, the integration of this structure is low, resulting in a large space occupied by the entire measurement device. Utility Model Content

[0006] The utility model aims to provide a device for measuring film thickness and refractive index, so as to solve the problems of low measuring accuracy, low integration and large occupied space of the existing measuring devices.

[0007] To achieve this purpose, the utility model adopts the following technical solutions:

[0008] A device for measuring film thickness and refractive index, comprising:

[0009] A storage table, on which a clamping assembly for fixing the prism and a cylinder for making the film sample fit tightly to the surface of the prism are arranged, and an air channel is opened in the storage table, and the air channel is used to connect the air source device and the cylinder;

[0010] A hollow shaft motor, a rotor of which is fixed to the storage platform and is used to drive the storage platform to rotate;

[0011] An air pipe, one end of which passes through the hollow shaft motor and is connected to the airway, and the other end of which is ventilated and connected to the air source device; wherein the air pipe is rotatably connected to the storage table, or the air pipe is rotatably connected to the air valve of the air source device.

[0012] Preferably, the clamping assembly comprises a base and an upper limit portion;

[0013] Along the extension direction of the cylinder, the base is provided with interconnected limiting grooves and avoidance grooves in sequence, the bottom end of the prism is arranged in the limiting groove and the avoidance groove, the limiting groove gradually shrinks toward the extension direction of the cylinder, and the avoidance groove is used to avoid the corners of the prism;

[0014] The upper limit portion abuts against the top of the prism, a slot is provided at the top of the prism, the opening direction of the slot is arranged on the side away from the cylinder, and a block matching the slot is provided at one end of the upper limit portion abutting against the prism.

[0015] Preferably, the base is made of ceramic, and the contact surface between the base and the prism is polished to an optical level.

[0016] Preferably, the clamping assembly comprises a C-shaped clamp, the clamp is fixed to the storage table, the clamp has the upper limit portion, and the base is fixed on the clamp and is detachably connected to the clamp.

[0017] Preferably, the cylinder includes an end cover and a piston rod; the end cover includes an integrally formed horizontal plate portion and a vertical plate portion, the horizontal plate portion is fixed to the storage table, a slide rail is provided on the horizontal plate portion, a slider is fixed to the protruding end of the piston rod, the slider is slidably connected to the slide rail, a limiting member is fixed to the end of the slider away from the piston rod, and the limiting member is used to abut the film sample so that the film sample fits tightly to the surface of the prism.

[0018] Preferably, the cylinder further includes a regulating valve and a cylinder barrel; a first flow channel is opened in the horizontal plate portion, and a second flow channel is opened in the vertical plate portion, and the air channel is connected to the interior of the cylinder barrel through the first flow channel, the second flow channel and the regulating valve in sequence.

[0019] Preferably, the position limiting member is provided with two mounting grooves, one of which is provided with a heating wire, and the other is provided with a thermocouple.

[0020] Preferably, a gap is left between the limiting member and the piston rod.

[0021] The storage platform is provided with a positioning groove that matches the horizontal plate portion, and the horizontal plate portion is arranged in the positioning groove.

[0022] Preferably, the cylinder is a single-acting cylinder.

[0023] Compared with the prior art, the utility model has the following beneficial effects:

[0024] The device adopts a hollow shaft motor and opens an air passage in the storage table. One end of the air pipe passes through the hollow shaft motor and is connected to the cylinder through the air passage, and the other end is ventilated and connected to the air source equipment. The air pipe is rotatably connected to the storage table, or the air pipe is rotatably connected to the air valve of the air source equipment. This design ensures the gas supply required by the cylinder during the rotation process, and the air pipe is relatively fixed, avoiding the problem of reduced measurement accuracy caused by air pipe swing in existing measuring devices, thereby improving the accuracy and reliability of the entire measuring device. In addition, the design of the air pipe passing through the hollow shaft motor and being connected to the cylinder through the air passage improves the integration of the device and makes the overall structure of the measuring device more compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0027] Figure 1Schematic diagram of the external structure of the measuring device in this embodiment;

[0028] Figure 2 Schematic diagram of the internal structure of the measuring device in this embodiment;

[0029] Figure 3 is an exploded view of the measuring device in this embodiment;

[0030] Figure 4 Schematic diagram of the structure of the clamping assembly in this embodiment.

[0031] Description of reference numerals:

[0032] 10. Storage table; 11. Airway;

[0033] 20. Clamping assembly; 21. Base; 211. Limiting groove; 212. Avoiding groove; 221. Upper limit portion; 22. Clamp;

[0034] 30. Cylinder; 31. End cover; 311. Horizontal plate; 312. Vertical plate; 32. Piston rod; 33. Slide rail; 34. Slider; 35. Stopper; 36. Regulating valve; 37. Cylinder barrel;

[0035] 40. Hollow shaft motor;

[0036] 50. Trachea;

[0037] 100. Prism; 101. Card slot. DETAILED DESCRIPTION

[0038] In order to make the utility model's purpose, features, and advantages more obvious and easy to understand, the following will be combined with the drawings in the utility model embodiments to clearly and completely describe the technical solutions in the utility model embodiments. Obviously, the embodiments described below are only part of the utility model embodiments, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0039] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0040] The technical solution of the utility model is further explained below with reference to the accompanying drawings and through specific implementation methods.

[0041] Reference Figures 1 to 4 The device for measuring film thickness and refractive index disclosed in this embodiment includes a platform 10 and an air pipe 50. The platform 10 is provided with a clamping assembly 20 for fixing a prism 100 and an air cylinder 30 for making the film sample closely fit the surface of the prism 100. An air channel 11 is provided in the platform 10, and the air channel 11 is used to connect the air source device and the air cylinder 30.

[0042] A hollow shaft motor 40 is arranged under the storage table 10, and the rotor of the hollow shaft motor 40 is fixed to the storage table 10, and is used to drive the storage table 10 to rotate; one end of the air pipe 50 passes through the hollow shaft motor 40 and is connected to the airway 11, and the other end is ventilated and connected to the air source equipment; wherein, the air pipe 50 is rotatably connected to the storage table 10, or the air pipe 50 is rotatably connected to the air valve of the air source equipment.

[0043] The device adopts a hollow shaft motor 40 and opens an air passage 11 in the storage table 10. One end of the air pipe 50 passes through the hollow shaft motor 40 and is connected to the cylinder 30 through the air passage 11, and the other end is ventilated and connected to the air source device, wherein the air pipe 50 is rotatably connected to the storage table 10, or the air pipe 50 is rotatably connected to the air valve of the air source device. This design ensures that the gas supply required by the cylinder 30 can still be guaranteed during the rotation process, and the air pipe 50 is relatively fixed, thereby avoiding the problem of reduced measurement accuracy caused by the swing of the air pipe 50 in the existing measuring device, thereby improving the accuracy and reliability of the entire measuring device; in addition, the design of the air pipe 50 passing through the hollow shaft motor 40 and being connected to the cylinder 30 through the air passage 11 improves the integration of the device and makes the overall structure of the measuring device more compact.

[0044] Reference Figure 4 The clamping assembly 20 includes a base 21 and an upper limit portion 221; along the extension direction of the cylinder 30, the base 21 is provided with a limit groove 211 and an avoidance groove 212 that are connected in sequence, and the bottom end of the prism 100 is arranged in the limit groove 211 and the avoidance groove 212, and the limit groove 211 gradually shrinks toward the extension direction of the cylinder 30, so as to ensure the stable placement of the prism 100, avoid the prism 100 from moving or shaking during the test, and improve the stability of the measurement; the avoidance groove 212 is used to avoid the edges and corners of the prism 100, effectively preventing the prism from being damaged due to contact;

[0045] The upper limit portion 221 abuts against the top of the prism 100, and a slot 101 is provided at the top of the prism 100. The opening direction of the slot 101 is set on the side away from the cylinder 30, and one end of the upper limit portion 221 abutting against the prism 100 is provided with a block matching the slot 101. The upper limit portion 221 is designed in conjunction with the slot 101 to firmly fix the prism 100, ensuring that it maintains a consistent position during the measurement process, thereby improving the measurement accuracy.

[0046] Among them, the base 21 is made of ceramic with high hardness and small deformation, which effectively eliminates the incident angle deviation caused by the displacement of the prism 100 under the force of the cylinder 30, and reduces the signal disturbance caused by the slight vibration of the prism 100; and the contact surface between the base 21 and the prism 100 is polished at the optical level to reduce damage to the prism 100 and extend the service life of the prism 100.

[0047] Reference Figure 4 The clamping assembly 20 includes a C-shaped clamp 22, which is fixed to the storage table 10. The clamp 22 has an upper limit portion 221. The base 21 is fixed to the clamp 22 and is detachably connected to the clamp 22 for easy installation and replacement.

[0048] Reference Figure 3 The cylinder 30 includes an end cover 31 and a piston rod 32; the end cover 31 includes an integrally formed horizontal plate portion 311 and a vertical plate portion 312, the horizontal plate portion 311 is fixed to the storage table 10, a slide rail 33 is provided on the horizontal plate portion 311, a slider 34 is fixed to the protruding end of the piston rod 32, the slider 34 is slidably connected to the slide rail 33, and a limiter 35 is fixed to the end of the slider 34 away from the piston rod 32, and the limiter 35 is used to abut the film sample so that the film sample fits tightly to the surface of the prism 100. The design of the slide rail 33 and the slider 34 ensures the linear movement of the piston rod 32, reduces the shaking of the limiter 35, and improves the stability of the film sample fitting the surface of the prism. A positioning groove matching the horizontal plate portion 311 is provided on the storage table 10, and the horizontal plate portion 311 is arranged in the positioning groove.

[0049] Reference Figure 3 The cylinder 30 also includes a regulating valve 36 and a cylinder barrel 37; a first flow channel is opened in the horizontal plate portion 311, and a second flow channel is opened in the vertical plate portion 312. The air channel 11 is connected to the interior of the cylinder barrel 37 through the first flow channel, the second flow channel and the regulating valve 36 in sequence.

[0050] Among them, the limiter 35 is provided with two mounting grooves, one of which is provided with a heating wire, and the other is provided with a thermocouple. The heating wire provides a heating function, and together with the thermocouple, it realizes precise temperature control, and can perform measurements under different temperature conditions, thereby improving the application range and measurement accuracy of the equipment. The thermocouple provides temperature feedback information to ensure that the control system is adjusted in real time, prevent overheating or underheating, protect the film sample, and improve the reliability of the measurement. A gap is left between the limiter 35 and the piston rod 32 to play a role in heat insulation.

[0051] The cylinder 30 is a single-acting cylinder, which has a simple structure, is easy to control, reduces complexity and failure points, and improves the reliability and maintenance convenience of the device.

[0052] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for measuring film thickness and refractive index, characterized in that: include: A storage platform (10), wherein a clamping assembly (20) for fixing the prism (100) and a cylinder (30) for making the film sample fit tightly against the surface of the prism (100) are arranged on the storage platform (10), and an air channel (11) is provided in the storage platform (10), and the air channel (11) is used to connect the air source device and the cylinder (30); A hollow shaft motor (40), the rotor of the hollow shaft motor (40) being fixed to the storage platform (10) and used for driving the storage platform (10) to rotate; An air pipe (50), one end of the air pipe (50) passes through the hollow shaft motor (40) to communicate with the air passage (11), and the other end of the air pipe is ventilated and connected to the air source device; wherein the air pipe (50) is rotatably connected to the storage table (10), or the air pipe (50) is rotatably connected to the air valve of the air source device.

2. The device for measuring film thickness and refractive index according to claim 1, characterized in that: The clamping assembly (20) comprises a base (21) and an upper limit portion (221); Along the extension direction of the cylinder (30), the base (21) is provided with a communicating limit groove (211) and an avoidance groove (212) in sequence, the bottom end of the prism (100) is arranged in the limit groove (211) and the avoidance groove (212), the limit groove (211) gradually shrinks toward the extension direction of the cylinder (30), and the avoidance groove (212) is used to avoid the corners of the prism (100); The upper limit portion (221) abuts against the top of the prism (100); a slot (101) is provided at the top of the prism (100); an opening direction of the slot (101) is arranged on a side away from the cylinder (30); and a block matching the slot (101) is provided at one end of the upper limit portion (221) abutting against the prism (100).

3. The device for measuring film thickness and refractive index according to claim 2, characterized in that: The base (21) is made of ceramic, and the contact surface between the base (21) and the prism (100) is polished to an optical level.

4. The device for measuring film thickness and refractive index according to claim 2, characterized in that: The clamping assembly (20) comprises a C-shaped clamp (22), the clamp (22) being fixed to the storage table (10), the clamp (22) having the upper limit portion (221), and the base (21) being fixed to the clamp (22) and detachably connected to the clamp (22).

5. The device for measuring film thickness and refractive index according to claim 1, characterized in that: The cylinder (30) comprises an end cover (31) and a piston rod (32); The end cover (31) comprises an integrally formed transverse plate portion (311) and a vertical plate portion (312); the transverse plate portion (311) is fixed to the storage table (10); a slide rail (33) is provided on the transverse plate portion (311); a slider (34) is fixed to the protruding end of the piston rod (32); the slider (34) is slidably connected to the slide rail (33); a limiting member (35) is fixed to one end of the slider (34) away from the piston rod (32); the limiting member (35) is used to abut against a thin film sample so that the thin film sample is tightly fitted to the surface of the prism (100).

6. The device for measuring film thickness and refractive index according to claim 5, characterized in that: The cylinder (30) further comprises a regulating valve (36) and a cylinder barrel (37); A first flow channel is provided in the horizontal plate portion (311), a second flow channel is provided in the vertical plate portion (312), and the air channel (11) is connected to the interior of the cylinder (37) via the first flow channel, the second flow channel and the regulating valve (36) in sequence.

7. The device for measuring film thickness and refractive index according to claim 5, characterized in that: The limiting member (35) is provided with two installation grooves, one of which is provided with a heating wire, and the other is provided with a thermocouple.

8. The device for measuring film thickness and refractive index according to claim 7, characterized in that: A gap is left between the limiting member (35) and the piston rod (32).

9. The device for measuring film thickness and refractive index according to claim 5, characterized in that: The storage platform (10) is provided with a positioning groove matching the transverse plate portion (311), and the transverse plate portion (311) is arranged in the positioning groove.

10. The device for measuring film thickness and refractive index according to claim 1, characterized in that: The cylinder (30) is a single-acting cylinder.

Images