Manufacturing method of film uniformity correction baffle

Abstract

The manufacturing method of the film uniformity correction baffle comprises the following steps: firstly, evaporating a proper amount of film material on a K9 substrate by using a film plating machine, then detecting the reflectivity of the substrate by using a detection instrument, and then converting the reflectivity into the film thickness. Different film thickness values can be converted from the substrates at different positions. Secondly, establishing a space rectangular coordinate system, describing a film material evaporation source position, a substrate position and a movement mode, and correcting mathematical factors such as a placement plane of a baffle plate; and a mathematical model is established again, the width of the correction baffle is calculated, manufacturing of the correction baffle is completed according to the width, finally, the film thicknesses on all the substrates are roughly the same, and it is guaranteed that the surface shape variation of the optical product after film coating meets the technical requirement. According to the method, a large amount of manpower and material resources can be saved, and compared with other manufacturing methods, the calculation result is more accurate, the number of experiments is smaller, the correction precision of the correction baffle is higher, and the technological level is more advanced.

Description

Technical Field

[0001] The invention relates to a method for manufacturing a film uniformity correction baffle, and belongs to the field of optical film coating. Background Art

[0002] With the rapid development of vacuum coating technology, product use requirements are gradually developing towards high-precision and high-tech directions, and the requirements for product uniformity are becoming higher and higher. Thin film uniformity refers to the property that the thickness of the film coated on the substrate to be coated changes with the position of the substrate in the vacuum chamber. It is an important indicator for measuring the optical performance of the product and the quality of the film layer.

[0003] The placement of important components such as the electron gun in the coating equipment determines the basic uniformity of the film layer of the product, but this characteristic deviates from the task index requirements, so uniformity adjustment is required. At present, domestic and foreign manufacturers use the production of correction baffles to compensate for product uniformity. After investigation, there are many ways to make baffles, but in practical applications, most of them are dominated by personal experience, lack of a complete set of theoretical design methods, and cannot intuitively analyze and calculate uniformity characteristics. The production of correction baffles can only be improved many times through a large number of experiments, which is time-consuming and labor-intensive, and the work is heavy and cumbersome. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and provide a method for manufacturing a thin film uniformity correction baffle, to digitize the entire coating process by establishing a spatial mathematical theoretical model, to intuitively explain the uniformity changes in the coating process, and to greatly reduce the number of correction experiments.

[0005] The technical solution of the present invention is: a method for manufacturing a thin film uniformity correction baffle, comprising:

[0006] 1) Select 5 clean glass substrates, clamp them on the coating tooling along the radial direction, place them evenly, and then hang the coating tooling on the workpiece plate of the coating machine;

[0007] 2) Put the film material to be evaporated into the coating machine, and ensure that there is no correction baffle between the hanging coating tooling and the film material evaporation source; start coating;

[0008] 3) After the coating is completed, the glass substrate is taken out, and the reflectivity of the glass substrate after coating is measured to obtain a reflectivity curve;

[0009] 4) Select a peak on the reflectivity curve, convert the reflectivity into film thickness using a spectrophotometer, and record the film thickness E of each substrate;

[0010] 5) Select a value J and calculate the film thickness difference Q = EJ;

[0011] 6) Establish a spatial rectangular coordinate system, with the origin being the intersection of the coating tooling and the evaporation source plane, measure the positions of the evaporation source and each substrate in the spatial rectangular coordinate system, and express them in coordinates;

[0012] 7) Taking the center of the coating tooling as the center of the circle and the length from the position of each substrate to the origin as the radius, the rotation track of the coating tooling is divided into 5 concentric circles;

[0013] 8) Divide the circumference of each concentric circle into N arc lengths;

[0014] 9) According to the film thickness E and the N equally divided arc lengths, calculate the arc length T that needs to be corrected;

[0015] 10) In the established spatial rectangular coordinate system, arbitrarily select the plane P where the correction baffle is placed;

[0016] 11) Randomly select a position when the substrate is rotating, measure the coordinates A1-A5 of each substrate at this time, connect the centers of the five substrates and the center of the evaporation source G to form five spatial straight lines, and find the intersection points of the five spatial straight lines and the spatial plane P. At this time, there are a total of five intersection points A6-A10;

[0017] 12) Correct the arc length using the arc length T that needs to be corrected, and then find another point B1--B5 on the corrected arc length based on the center of the circle and the coordinates A1-A5 of each substrate;

[0018] 13) Connect points B1-B5 with the center of the evaporation source G to form five spatial straight lines, and calculate the intersection points B6-B10 of these five spatial straight lines and the plane P;

[0019] 14) Make a correction plate based on the coordinates of points A6-A10 and B6-B10.

[0020] The glass substrate is a K9 glass substrate with a diameter of 25-35 mm.

[0021] The workpiece disc is a workpiece disc that only revolves around the sun but does not rotate on its own axis.

[0022] The value J is smaller than the minimum substrate thickness among the five substrates.

[0023] Said N≥1000.

[0024] The arc length T that needs to be corrected is calculated based on the film thickness E and the N equally divided arc lengths, including: assuming that the film thickness E is the sum of N unit thicknesses, dividing the film thickness E by the number of arc lengths N, to obtain the unit thickness a, that is, a=E / N; then calculating the film thickness difference Q divided by a, to obtain the corresponding number of arc lengths M on each concentric circle, that is, M=Q / a; assuming the circumference is C, the arc length that needs to be corrected is T=C×(M / N).

[0025] The method of making a correction plate according to the coordinates of points A6-A10 and B6-B10 includes:

[0026] Mark the coordinates of points A6-A10 and B6-B10 on a two-dimensional plane baffle, and connect points A6-A10, B6-B10, A10-B10, and A6-B6 in sequence. The enclosed part is the manufactured correction plate.

[0027] The method further includes step 15), wherein the manufactured correction plate is hung at a designated position to conduct a uniformity verification experiment.

[0028] The produced correction plate is hung at the designated position, and the uniformity verification experiment includes: hanging the produced correction plate at the designated position, repeating steps 1)-4), calculating a new film thickness E°, if E-E°=Q, it means that the second experimental result is relatively ideal; if E-E°>Q or E-E°<Q, that is, E°≠J, it means that there is a difference between the actual experimental data and the ideal setting data; setting the Tooling value H, H is used to correct the data, H=(E-E°) / Q; then the actual arc length T° that needs to be corrected is T / H, repeating steps 10)-14), performing secondary processing on the correction plate, and after processing, hanging it on the coating machine, and returning to step 1) again to verify uniformity.

[0029] The advantages of the present invention compared with the prior art are:

[0030] 1. Most of the existing technologies are based on experience and lack a complete set of theoretical calculations, while the calculation results of the present invention are accurate and have sufficient theoretical basis;

[0031] 2. The present invention introduces an arc length correction value based on the establishment of a theoretical calculation system, thereby obtaining the actual required length;

[0032] 3. The present invention can intuitively perform uniformity characteristic analysis and calculation, with a small number of experimental iterations, saving a lot of manpower and material resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a diagram of the theoretical model of the method of the present invention. DETAILED DESCRIPTION

[0034] like Figure 1 As shown, a method for manufacturing a thin film uniformity correction baffle includes:

[0035] 1) Select 5 clean glass substrates, clamp them on the coating tooling along the radial direction, place them evenly, and then hang the coating tooling on the workpiece plate of the coating machine;

[0036] 2) Put the film material to be evaporated into the coating machine, and ensure that there is no correction baffle between the hanging coating tooling and the film material evaporation source; start coating;

[0037] 3) After the coating is completed, the glass substrate is taken out, and the reflectivity of the glass substrate after coating is measured to obtain a reflectivity curve;

[0038] 4) Select a peak on the reflectivity curve, convert the reflectivity into film thickness using a spectrophotometer, and record the film thickness E of each substrate;

[0039] 5) Select a value J and calculate the film thickness difference Q = EJ;

[0040] 6) Establish a spatial rectangular coordinate system, with the origin being the intersection of the coating tooling and the evaporation source plane, measure the positions of the evaporation source and each substrate in the spatial rectangular coordinate system, and express them in coordinates;

[0041] 7) Taking the center of the coating tooling as the center of the circle and the length from the position of each substrate to the origin as the radius, the rotation track of the coating tooling is divided into 5 concentric circles;

[0042] 8) Divide the circumference of each concentric circle into N arc lengths;

[0043] 9) According to the film thickness E and the N equally divided arc lengths, calculate the arc length T that needs to be corrected;

[0044] 10) In the established spatial rectangular coordinate system, arbitrarily select the plane P where the correction baffle is placed;

[0045] 11) Randomly select a position when the substrate is rotating, measure the coordinates A1-A5 of each substrate at this time, connect the centers of the five substrates and the center of the evaporation source G to form five spatial straight lines, and find the intersection points of the five spatial straight lines and the spatial plane P. At this time, there are a total of five intersection points A6-A10;

[0046] 12) Correct the arc length using the arc length T that needs to be corrected, and then find another point B1--B5 on the corrected arc length based on the center of the circle and the coordinates A1-A5 of each substrate;

[0047] 13) Connect points B1-B5 with the center of the evaporation source G to form five spatial straight lines, and calculate the intersection points B6-B10 of these five spatial straight lines and the plane P;

[0048] 14) Make a correction plate based on the coordinates of points A6-A10 and B6-B10.

[0049] The glass substrate is a K9 glass substrate with a diameter of 25-35 mm.

[0050] The workpiece disc is a workpiece disc that only revolves around the sun but does not rotate on its own axis.

[0051] The value J is smaller than the minimum substrate thickness among the five substrates.

[0052] Said N≥1000.

[0053] The arc length T that needs to be corrected is calculated based on the film thickness E and the N equally divided arc lengths, including: assuming that the film thickness E is the sum of N unit thicknesses, dividing the film thickness E by the number of arc lengths N, to obtain the unit thickness a, that is, a=E / N; then calculating the film thickness difference Q divided by a, to obtain the corresponding number of arc lengths M on each concentric circle, that is, M=Q / a; assuming the circumference is C, the arc length that needs to be corrected is T=C×(M / N).

[0054] The method of making a correction plate according to the coordinates of points A6-A10 and B6-B10 includes:

[0055] Mark the coordinates of points A6-A10 and B6-B10 on a two-dimensional plane baffle, and connect points A6-A10, B6-B10, A10-B10, and A6-B6 in sequence. The enclosed part is the manufactured correction plate.

[0056] It also includes step 15), hanging the manufactured correction plate at a designated position to conduct a uniformity verification experiment. The uniformity verification experiment of hanging the manufactured correction plate at a designated position includes: hanging the manufactured correction plate at a designated position, repeating steps 1)-4), calculating a new film thickness E°, if E-E°=Q, it means that the second experimental result is relatively ideal; if E-E°>Q or E-E°<Q, that is, E°≠J, it means that there is a difference between the actual experimental data and the ideal setting data; setting the Tooling value H, H is used to correct the data, H=(E-E°) / Q; then the actual arc length that needs to be corrected T°=T / H, repeating steps 10)-14), performing secondary processing on the correction plate, after processing, hanging it on the coating machine, and returning to step 1) again to verify uniformity.

[0057] Example

[0058] 1. A product with a diameter of 1100 mm was plated on a 2500 mm diameter coating machine. Five points were selected in the radial direction to plate a single layer of film. The film thickness was simulated. The thickness is shown in Table 1.

[0059] Table 1 Fitting film thickness at each point without uniformity correction plate (nm)

[0060] Pick Point A1 A2 A3 A4 A5 Film thickness E 380.3 388.5 396.7 408.6 415.5 Radius R 300mm 500mm 700mm 900mm 1100mm

[0061] 2. Select the value J, J = 360nm, and calculate the difference between A1-A5 and the value J, as shown in Table 2.

[0062] Table 2 Film thickness difference at each point (nm)

[0063]

[0064]

[0065] 3. Taking point A1 as an example, take N1=1000, radius R1=300nm, the coordinates of point A1 at a certain moment are A1(0,300,1400), and establish the formula, T1=2ΠR1·Q1 / E1, where E1 represents the film thickness at point A1; using the arc length T1, point A1 on the arc length, and radius R1, calculate the coordinates of another point B1 on the arc length, that is, B1(98,283.5,1400). Similarly, the coordinates of points A2-A5 and B2-B5 can be calculated.

[0066] 4. Under the established mathematical theoretical model, the calculation formula of the intersection of a straight line and a plane is applied to obtain the coordinates of A6 as (314.28, 214.28, 1000). Similarly, the coordinates of B6 can be calculated as (384.28, 202.5, 1000). The length D1 = 69 can be calculated. Similarly, D2-D5 can be calculated.

[0067] 5. According to D1--D5, make a correction baffle, then hang it at the specified position of the coating machine and coat it again. The film thickness difference and Tooling value at each point after coating are shown in Table 3.

[0068] Table 3 Film thickness difference and Tooling value at each point (nm)

[0069]

[0070] 6. Taking point A1 as an example, the film thickness that needs to be corrected is 20.3nm, but it is actually only corrected by 18.3nm, which means that the length D1 is too short, so the length of D1 needs to be increased. According to N1 and Tooling value H1, the corrected arc length T1 is obtained, and then D1 is corrected. Similarly, D2-D5 are corrected. After the correction is completed, the correction baffle is made again to complete the experiment.

[0071] 7. After the experiment is completed, the film thickness at each point is shown in Table 4.

[0072] Table 4 Final fitted film thickness at each point using the uniformity correction plate (nm)

[0073] Pick Point A1 A2 A3 A4 A5 Film thickness E 359 365 364 363 365

[0074] result:

[0075] The film thickness uniformity is calculated as follows:

[0076] Maximum film thickness difference = thickest film thickness - thinnest film thickness

[0077] Center film thickness = (maximum film thickness + minimum film thickness) ÷ 2

[0078] Film thickness uniformity = (maximum film thickness difference ÷ center film thickness) × 100%

[0079] When baffles are not used, film thickness uniformity S = 8.8%

[0080] After using the correction baffle, the film thickness uniformity S0 = 1.6%

[0081] Conclusion: Within the 1100mm diameter, the uniformity S is improved from 8.8% to 1.6%.

[0082] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for manufacturing a thin film uniformity correction baffle, characterized in that: include: 1) Select 5 clean glass substrates, clamp them on the coating tooling along the radial direction, place them evenly, and then hang the coating tooling on the workpiece plate of the coating machine; 2) Put the film material to be evaporated into the coating machine, and ensure that there is no correction baffle between the hanging coating tooling and the film material evaporation source; start coating; 3) After the coating is completed, the glass substrate is taken out, and the reflectivity of the glass substrate after coating is measured to obtain a reflectivity curve; 4) Select a peak on the reflectivity curve, convert the reflectivity into film thickness using a spectrophotometer, and record the film thickness E of each substrate; 5) Select a value J and calculate the film thickness difference Q = EJ; 6) Establish a spatial rectangular coordinate system, with the origin being the intersection of the coating tooling and the evaporation source plane, measure the positions of the evaporation source and each substrate in the spatial rectangular coordinate system, and express them in coordinates; 7) Taking the center of the coating tooling as the center of the circle and the length from the position of each substrate to the origin as the radius, the rotation track of the coating tooling is divided into 5 concentric circles; 8) Divide the circumference of each concentric circle into N arc lengths; 9) According to the film thickness E and the N equally divided arc lengths, calculate the arc length T that needs to be corrected; 10) In the established spatial rectangular coordinate system, arbitrarily select the plane P where the correction baffle is placed; 11) Randomly select a position when the substrate is rotating, measure the coordinates A1-A5 of each substrate at this time, connect the centers of the five substrates and the center of the evaporation source G to form five spatial straight lines, and find the intersection points of the five spatial straight lines and the spatial plane P. At this time, there are a total of five intersection points A6-A10; 12) Correct the arc length using the arc length T that needs to be corrected, and then find another point B1--B5 on the corrected arc length based on the center of the circle and the coordinates A1-A5 of each substrate; 13) Connect points B1-B5 with the center of the evaporation source G to form five spatial straight lines, and calculate the intersection points B6-B10 of these five spatial straight lines and the plane P; 14) Make a correction plate based on the coordinates of points A6-A10 and B6-B10.

2. The method for manufacturing a thin film uniformity correction baffle according to claim 1, characterized in that: The glass substrate is a K9 glass substrate with a diameter of 25-35 mm.

3. The method for manufacturing a thin film uniformity correction baffle according to claim 1, characterized in that: The workpiece disc is a workpiece disc that only revolves around the sun but does not rotate on its own axis.

4. The method for manufacturing a thin film uniformity correction baffle according to claim 1, characterized in that: The value J is smaller than the minimum substrate thickness among the five substrates.

5. The method for manufacturing a thin film uniformity correction baffle according to claim 1, characterized in that: Said N≥1000.

6. The method for manufacturing a thin film uniformity correction baffle according to claim 1, characterized in that: The arc length T that needs to be corrected is calculated based on the film thickness E and the N equally divided arc lengths, including: assuming that the film thickness E is the sum of N unit thicknesses, and calculating the unit thickness a=E / N; then obtaining the corresponding number of arc lengths on each concentric circle M=Q / a; assuming the circumference is C, the arc length that needs to be corrected is T=C×(M / N).

7. The method for manufacturing a thin film uniformity correction baffle according to claim 1, characterized in that: The method of making a correction plate according to the coordinates of points A6-A10 and B6-B10 includes: Mark the coordinates of points A6-A10 and B6-B10 on a two-dimensional plane baffle, and connect points A6-A10, B6-B10, A10-B10, and A6-B6 in sequence. The enclosed part is the manufactured correction plate.

8. The method for manufacturing a thin film uniformity correction baffle according to claim 1, characterized in that: The method further includes step 15), wherein the manufactured correction plate is hung at a designated position to conduct a uniformity verification experiment.

9. The method for manufacturing a thin film uniformity correction baffle according to claim 6, characterized in that: The produced correction plate is hung at the designated position, and the uniformity verification experiment includes: hanging the produced correction plate at the designated position, repeating steps 1)-4), calculating a new film thickness E°, if E-E°=Q, it means that the second experimental result is relatively ideal; if E-E°>Q or E-E°<Q, that is, E°≠J, it means that there is a difference between the actual experimental data and the ideal setting data; setting the Tooling value H, H is used to correct the data, H=(E-E°) / Q; then the actual arc length T° that needs to be corrected is T / H, repeating steps 10)-14), performing secondary processing on the correction plate, and after processing, hanging it on the coating machine, and returning to step 1) again to verify uniformity.

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