Rotating speed stability testing device and method for sputtering protection rotating unit

Abstract

The invention discloses a rotating speed stability testing device and method for a sputtering protection rotating unit, and the device comprises a laser generator, a half-transparent and half-reflecting mirror, a first reflector, a second reflector, a photodiode, and a collector for collecting the signal of the photodiode. The first reflecting mirror and the second reflecting mirror are arranged on the two sides of the target shooting rotating wheel, light generated by the laser generator passes through the semi-transparent and semi-reflecting mirror, then reaches the second reflecting mirror through the first reflecting mirror and an opening in the target shooting rotating wheel, and is reflected back to the first reflecting mirror through the second reflecting mirror; the light is reflected to the semi-transparent and semi-reflecting mirror through the first reflecting mirror, and the light is reflected to the photodiode through the semi-transparent and semi-reflecting mirror. According to the detection device and the test method, real-time detection can be realized, the occupied volume in the vacuum cavity is small, the detection sensitivity is high, and the precision is high.

Description

Technical Field

[0001] The invention relates to a rotation speed stability testing device and a testing method for a rotating unit, and relates to the technical field of laser target shooting. Background Art

[0002] Laser target shooting refers to the process of bombarding target materials with high-power lasers. This process can be used to carry out many applications such as particle acceleration, extreme ultraviolet radiation generation, and sputtering coating.

[0003] The Chinese invention patent application number CN202210987946.6 discloses a laser target shooting anti-sputtering device and method, which includes a rotatable wheel with a target hole provided at a non-center position of the wheel. During laser shooting, the target hole is located in the laser light path, allowing the laser to pass through the wheel and bombard the target; after laser shooting, the wheel rotates so that the target hole moves away from the laser light path, and the splashes generated by the shooting are blocked by the wheel.

[0004] However, the above laser target shooting anti-sputtering device may have problems such as unstable speed and eccentricity of the rotatable wheel after long-term operation, which may affect the target shooting process.

[0005] Due to the above reasons, it is necessary to study the stability testing device of the target wheel to solve the above problems. Summary of the Invention

[0006] In order to overcome the above problems, the inventors conducted in-depth research and designed a speed stability test device for a sputtering protection rotating unit, which includes a laser generator, a semi-transparent and semi-reflective mirror, a first reflector, a second reflector, a photodiode, and a collector for collecting the photodiode signal.

[0007] The first reflector and the second reflector are arranged on both sides of the targeting wheel. The light generated by the laser generator passes through the semi-transparent and semi-reflective mirror, and then reaches the second reflector after passing through the first reflector and the opening on the targeting wheel. The second reflector reflects the light back to the first reflector, and the first reflector reflects the light to the semi-transparent and semi-reflective mirror, and the semi-transparent and semi-reflective mirror reflects the light to the photodiode.

[0008] In a preferred embodiment, the first reflector and the second reflector are arranged in a laser targeting vacuum chamber.

[0009] The laser generator, the semi-transparent and semi-reflective mirror and the photodiode are arranged outside the laser targeting vacuum chamber.

[0010] In a preferred embodiment, a narrowband filter is provided between the semi-transparent and semi-reflective mirror and the photodiode.

[0011] In a preferred embodiment, the light beam generated by the laser generator 1 is less than 1 mm.

[0012] The present invention also discloses a method for testing the rotational speed stability of a sputtering protection rotating unit for high-frequency laser target shooting, which is implemented using one of the above-mentioned detection devices and includes the following steps:

[0013] S1, rotate the target wheel, turn on the laser generator, and obtain the signal of the photodiode through the collector;

[0014] S2, obtaining at least two signals, and taking the difference between the time interval between the rising edges of the two adjacent signals and the time interval of the stable target wheel as the detection time width;

[0015] S3. Setting an unstable threshold value that is smaller than a standard time width: When the detected time width is larger than the unstable threshold value, it is considered that the rotation of the target wheel is unstable; otherwise, it is considered that the rotation of the target wheel is stable.

[0016] In a preferred embodiment, before S1, there is further step S0, the target wheel is stationary, and the angles of the first reflector and the second reflector are adjusted so that the light generated by the laser generator 1 passes through the center of the opening of the wheel.

[0017] In a preferred embodiment, in S3, the standard time width ΔT is expressed as:

[0018]

[0019] Among them, Δθ represents the rotation angle of the targeting wheel when the laser of the detection device passes through the hole on the targeting wheel, ω represents the rotation angular velocity of the targeting wheel, r1 represents the aperture of the hole on the targeting wheel, r0 represents the spot radius of the laser generated by the laser generator, and r represents the distance between the center of the targeting wheel and the center of the spot of the laser of the detection device on the targeting wheel.

[0020] In a preferred embodiment, when the rotation of the target wheel becomes unstable, the method further comprises the following steps:

[0021] Step S4: stop laser target shooting and issue an early warning to remind the target wheel that maintenance is required;

[0022] S5. After maintaining the target wheel, repeat steps S1-S4 until the target wheel rotates stably.

[0023] The present invention also discloses a stable rotation measurement method, comprising the following steps:

[0024] A circular hole is provided on the rotating wheel;

[0025] A laser generator, a semi-transparent and semi-reflective mirror, a first reflector, a second reflector, a photodiode and a collector for collecting photodiode signals are provided.

[0026] The first reflector and the second reflector are arranged on both sides of the rotating wheel. The light generated by the laser generator passes through the semi-transparent and semi-reflective mirror, passes through the first reflector and the opening on the rotating wheel, and reaches the second reflector. The second reflector reflects the light back to the first reflector. The first reflector reflects the light to the semi-transparent and semi-reflective mirror, and the semi-transparent and semi-reflective mirror reflects the light to the photodiode.

[0027] Rotate the wheel, turn on the laser to illuminate the circular hole, and obtain the signal of the photodiode through the collector;

[0028] Acquire at least two signals, and use the difference between the time interval between the rising edges of the two adjacent signals and the time interval during which the target wheel is stable as the detection time width;

[0029] An unstable threshold value smaller than the standard time width is set: when the detected time width is greater than the unstable threshold value, the rotation of the target wheel is considered unstable; otherwise, the rotation of the target wheel is considered stable.

[0030] The beneficial effects of the present invention include:

[0031] (1) It occupies a small volume in the vacuum chamber and will not affect the target shooting process;

[0032] (2) High detection sensitivity and high accuracy;

[0033] (3) Real-time detection can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic structural diagram of a target wheel stability detection device according to a preferred embodiment of the present invention is shown;

[0035] Figure 2 A schematic structural diagram of a target wheel stability detection device according to a preferred embodiment of the present invention is shown;

[0036] Figure 3 A schematic diagram showing the time intervals when the target wheel is stable and unstable;

[0037] Figure 4 An annotation diagram showing the standard time width acquisition process;

[0038] Figure 5 A schematic diagram of the internal structure of the laser targeting vacuum chamber is shown.

[0039] Explanation of Figure Numbers

[0040] 1-Laser generator;

[0041] 2- half-transparent half-reflective mirror;

[0042] 3- first reflector;

[0043] 4- second reflector;

[0044] 5- Photodiode;

[0045] 6-Narrow band filter;

[0046] 9-Target wheel. DETAILED DESCRIPTION

[0047] The present invention will be described in further detail below with reference to the accompanying drawings and examples, through which the features and advantages of the present invention will become more clearly understood.

[0048] The word "exemplary" is used exclusively herein to mean "serving as an example, example, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0049] According to the present invention, a speed stability test device for a sputtering protection rotating unit is provided. Figure 1 As shown, it includes a laser generator 1, a semi-transparent and semi-reflective mirror 2, a first reflector 3, a second reflector 4, a photodiode 5 and a collector for collecting signals from the photodiode 5.

[0050] The first reflector 3 and the second reflector 4 are arranged on both sides of the targeting wheel 9. The light generated by the laser generator 1 passes through the semi-transparent and semi-reflective mirror 2, and then reaches the second reflector 4 after passing through the first reflector 3 and the opening on the targeting wheel 9. The second reflector 4 reflects the light back to the first reflector 3, and the first reflector 3 reflects the light to the semi-transparent and semi-reflective mirror 2, and the semi-transparent and semi-reflective mirror 2 reflects the light to the photodiode 5.

[0051] The semi-transparent and semi-reflective mirror is a commonly used optical device, one surface of which allows light to pass through and the other surface of which reflects light.

[0052] The photodiode is a commonly used optical device, which is excited when exposed to light and converts the light signal into an electrical signal, which is then collected by a collector.

[0053] In a preferred embodiment, the laser generator 1 can be a low-power laser transmitter, such as a laser pen.

[0054] In laser targeting for detecting repetitive laser targeting, there are a large number of optical devices in the vacuum chamber. The volume of the chamber is limited. Except for the necessary devices, the available space in the chamber is very small. Adding devices is easy to block the light path between the optical devices, especially the space near the target wheel is small. Its structure is as follows Figure 5As shown, it is difficult to apply to large-volume detection equipment and a large number of device units. In addition, due to the vacuum characteristics, the heating device in the vacuum chamber will accumulate heat, causing it to malfunction or even burn out.

[0055] In a preferred embodiment, the first reflector 3 and the second reflector 4 are arranged in a laser targeting vacuum chamber.

[0056] The laser generator 1, semi-transparent and semi-reflective mirror 2, and photodiode 5 are located outside the laser targeting vacuum chamber. Since only two reflectors are required within the vacuum chamber, they occupy virtually no additional volume within the chamber and do not affect the layout within the chamber. Furthermore, placing the laser generator and photodiode outside the vacuum chamber not only alleviates the problem of limited space within the chamber and solves the problem of photodiode heating, but also avoids the difficulty of routing wires for collecting the photodiode signal.

[0057] In actual use, astigmatism will be generated during laser target shooting. This astigmatism may be reflected onto the photodiode through the semi-transparent and semi-reflective mirror, causing the photodiode to generate a signal and affect the detection results.

[0058] In a preferred embodiment, a narrowband filter 6 is provided between the semi-transparent and semi-reflective mirror 2 and the photodiode 5. The narrowband filter filters the light irradiating the photodiode so that only the laser frequency generated by the laser generator can pass through the filter, thereby preventing the laser targeting process from affecting the wheel stability detection.

[0059] Generally, the diameter of the holes on the target wheel is in the order of centimeters, usually less than 10 cm. According to a preferred embodiment of the present invention, the beam generated by the laser generator 1 is less than 1 mm, so as to obtain the best detection accuracy while ensuring sensitivity.

[0060] In the present invention, the first reflector 3 and the second reflector 4 are not arranged in the laser targeting light path to avoid affecting the laser targeting.

[0061] The optical path formed by the detection device in the vacuum chamber can intersect with the optical path during laser targeting, that is, the stability of the targeting wheel can be detected while the laser is targeting. The optical path of the detection device at the targeting wheel can also be set at the point farthest from the laser targeting optical path, such as Figure 2 As shown, the stability of the target wheel is detected before laser target shooting, thereby stopping the target shooting.

[0062] The present invention also discloses a method for testing the rotational speed stability of a sputtering protection rotating unit, which is implemented using one of the above-mentioned detection devices and includes the following steps:

[0063] S1, rotate the target wheel 9, turn on the laser generator 1, and obtain the signal of the photodiode 5 through the collector;

[0064] S2, obtaining at least two signals, and taking the difference between the time interval between the rising edges of the two adjacent signals and the time interval of the stable target wheel as the detection time width;

[0065] S3. Setting an unstable threshold value that is smaller than a standard time width: When the detected time width is larger than the unstable threshold value, it is considered that the rotation of the target wheel is unstable; otherwise, it is considered that the rotation of the target wheel is stable.

[0066] The instability threshold can be freely set by those skilled in the art according to actual needs and is not particularly limited in the present invention.

[0067] According to the present invention, the optical path is used to detect the stability of the target wheel. Compared with other detection methods, such as mechanical vibration methods, the detection accuracy is high and the space occupied is small.

[0068] Preferably, before S1, there is further step S0, the stationary rotating wheel is used as the target rotating wheel, and the angles of the first reflector and the second reflector are adjusted so that the light generated by the laser generator passes through the center position of the opening of the rotating wheel.

[0069] Through this step, the time for the photodiode to generate a signal can be increased, thereby further improving the detection accuracy.

[0070] In S2, the time interval between consecutive signals is detected, and the difference between the time interval between the rising edges of two adjacent signals and the time interval of the stable target wheel is used as the detection time width.

[0071] Specifically, at least two signal detections are performed, such as Figure 3 As shown, in two adjacent signals, the difference (t2-t0) between the time interval t1 between the two signal rising edges and the time interval t0 between the two signal rising edges when the wheel rotates stably is used as the detection time width.

[0072] The time interval between two rising edges of the signal when the wheel rotates stably can be obtained through theoretical calculation. The specific calculation process is not described in detail in the present invention, and those skilled in the art can obtain it through theoretical deduction.

[0073] According to the present invention, in an ideal state, that is, when the rotation of the target wheel is completely stable, the detection time width is 0. As the rotation instability of the target wheel increases, the detection time width will gradually increase.

[0074] Obviously, in the present invention, signal detection can be performed continuously, and the detection time width can be continuously obtained by relying on three adjacent signals.

[0075] In a preferred embodiment, in S3, the standard time width ΔT is expressed as:

[0076]

[0077] Among them, Δθ represents the rotation angle of the targeting wheel when the laser of the detection device passes through the hole on the targeting wheel, ω represents the rotation angular velocity of the targeting wheel, r1 represents the aperture of the hole on the targeting wheel, r0 represents the spot radius of the laser generated by the laser generator, and r represents the distance between the center of the targeting wheel and the center of the spot of the laser of the detection device on the targeting wheel.

[0078] According to the present invention, the standard time width is the maximum detection time width deviation allowed during target shooting. When the detection time width exceeds the standard time width, the laser can no longer pass through the target shooting wheel. Δθ is the maximum angle allowed for the wheel to deviate from the center of the laser spot. Figure 4 shown.

[0079] In actual working conditions, when the detection time width is lower than the instability threshold, the laser targeting device can still achieve targeting. At this time, it is considered that the rotation of the targeting wheel is stable; as the detection time width gradually increases, the rotation stability of the targeting wheel deteriorates. When it exceeds the instability threshold, the energy of the laser of the laser targeting device passing through the opening of the targeting wheel becomes smaller, which not only causes the targeting to fail, but may also damage the targeting wheel.

[0080] In a preferred embodiment, when the rotation of the target wheel becomes unstable, the method further comprises the following steps:

[0081] Step S4: stop laser target shooting and issue an early warning to remind the target wheel that maintenance is required;

[0082] S5. After maintaining the target wheel, repeat steps S1-S4 until the target wheel rotates stably.

[0083] It should be noted that, in addition to high-frequency laser target shooting, those skilled in the art can also use the device and method disclosed in the present invention, after adaptive modification, to detect the rotational stability of other wheels.

[0084] The present invention also discloses a stable rotation measurement method, comprising the following steps:

[0085] A circular hole is provided on the rotating wheel;

[0086] A laser generator, a semi-transparent and semi-reflective mirror, a first reflector, a second reflector, a photodiode and a collector for collecting photodiode signals are provided;

[0087] The first reflector and the second reflector are arranged on both sides of the rotating wheel. The light generated by the laser generator passes through the semi-transparent and semi-reflective mirror, passes through the first reflector and the opening on the rotating wheel, and reaches the second reflector. The second reflector reflects the light back to the first reflector. The first reflector reflects the light to the semi-transparent and semi-reflective mirror, and the semi-transparent and semi-reflective mirror reflects the light to the photodiode.

[0088] Rotate the wheel, turn on the laser to illuminate the circular hole, and obtain the signal of the photodiode through the collector;

[0089] Acquire at least two signals, and use the difference between the time interval between the rising edges of the two adjacent signals and the time interval during which the target wheel is stable as the detection time width;

[0090] An unstable threshold value smaller than the standard time width is set: when the detected time width is greater than the unstable threshold value, the rotation of the target wheel is considered unstable; otherwise, the rotation of the target wheel is considered stable.

[0091] Example

[0092] Example 1

[0093] The stability detection device for a target wheel is used to detect the stability of a target wheel of a laser target. The target wheel stability detection device includes a laser generator 1, a semi-transparent and semi-reflective mirror 2, a first reflector 3, a second reflector 4, a photodiode 5, and a collector for collecting signals from the photodiode 5.

[0094] The first reflector 3 and the second reflector 4 are arranged on both sides of the targeting wheel 9. The light generated by the laser generator 1 passes through the semi-transparent and semi-reflective mirror 2, and then reaches the second reflector 4 after passing through the first reflector 3 and the opening on the targeting wheel 9. The second reflector 4 reflects the light back to the first reflector 3, and the first reflector 3 reflects the light to the semi-transparent and semi-reflective mirror 2, and the semi-transparent and semi-reflective mirror 2 reflects the light to the photodiode 5.

[0095] The first reflector 3 and the second reflector 4 are arranged in the laser targeting vacuum chamber.

[0096] The laser generator 1, the semi-transparent and semi-reflective mirror 2 and the photodiode 5 are arranged outside the laser targeting vacuum chamber.

[0097] A narrowband filter 6 is provided between the semi-transparent mirror 2 and the photodiode 5 .

[0098] The speed stability test method of the sputter protection rotating unit includes the following steps:

[0099] S1, rotate the target wheel, turn on the laser generator, and obtain the signal of the photodiode through the collector;

[0100] S2, obtaining at least two signals, and taking the difference between the time interval between the rising edges of the two adjacent signals and the time interval of the stable target wheel as the detection time width;

[0101] S3. Setting an unstable threshold value that is smaller than a standard time width: When the detected time width is larger than the unstable threshold value, it is considered that the rotation of the target wheel is unstable; otherwise, it is considered that the rotation of the target wheel is stable.

[0102] The standard time width ΔT is expressed as:

[0103]

[0104] According to the actual size and rotation speed of the wheel used in laser targeting, the standard time width is 370 μs obtained by the above formula.

[0105] The time width results obtained by the detection are shown in Table 1.

[0106] Table 1

[0107]

[0108] The instability threshold is set to 180 μs. According to Table 1, the time width of some detections is greater than the instability threshold, indicating that the wheel stability is abnormal.

[0109] The wheel was adjusted and tested again. The error was less than 100 μs, indicating that the wheel was stable.

[0110] Through the above process, the state of the target wheel can be accurately judged, thereby controlling the target process more safely.

[0111] In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front," and "rear" and the like, indicating positions or locations, are based on the operating state of the present invention and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0112] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integrated conventional connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium, or they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0113] The present invention has been described above with reference to preferred embodiments, but these embodiments are merely exemplary and serve only as illustrations. On this basis, various replacements and improvements can be made to the present invention, all of which fall within the scope of protection of the present invention.

Claims

1. A device for testing the rotational speed stability of a sputtering protection rotating unit, characterized in that: The invention comprises a laser generator (1), a semi-transparent and semi-reflective mirror (2), a first reflector (3), a second reflector (4), a photodiode (5), and a collector for collecting signals from the photodiode (5). The first reflector (3) and the second reflector (4) are arranged on both sides of the target wheel (9); the light generated by the laser generator (1) passes through the semi-transparent and semi-reflective mirror (2), and then reaches the second reflector (4) after passing through the first reflector (3) and the opening on the target wheel (9); the second reflector (4) reflects the light back to the first reflector (3); the first reflector (3) reflects the light to the semi-transparent and semi-reflective mirror (2), and the semi-transparent and semi-reflective mirror (2) reflects the light to the photodiode (5).

2. The speed stability testing device of the sputtering protection rotating unit according to claim 1, characterized in that: The first reflecting mirror (3) and the second reflecting mirror (4) are arranged in a laser targeting vacuum chamber. The laser generator (1), the semi-transparent and semi-reflective mirror (2) and the photodiode (5) are arranged outside the laser targeting vacuum chamber.

3. The speed stability testing device of the sputtering protection rotating unit according to claim 1, characterized in that: A narrowband filter (6) is provided between the semi-transparent and semi-reflective mirror (2) and the photodiode (5).

4. The speed stability testing device of the sputtering protection rotating unit according to claim 1, characterized in that: The light beam generated by the laser generator (1) is less than 1 mm.

5. A method for testing the rotational speed stability of a sputtering protection rotating unit for detecting high-frequency laser target shooting, characterized in that: The detection device according to any one of claims 1 to 4 is used for implementation, comprising the following steps: S1, rotate the target wheel, turn on the laser generator, and obtain the signal of the photodiode through the collector; S2, obtaining at least two signals, and taking the difference between the time interval between the rising edges of the two adjacent signals and the time interval of the stable target wheel as the detection time width; S3. Setting an unstable threshold value that is smaller than a standard time width: When the detected time width is larger than the unstable threshold value, it is considered that the rotation of the target wheel is unstable; otherwise, it is considered that the rotation of the target wheel is stable.

6. The method for testing the rotational speed stability of a sputtering protection rotating unit for detecting high-frequency laser target shooting according to claim 5, characterized in that: Before S1, there is also step S0, the stationary rotating wheel and the target rotating wheel are used to adjust the angles of the first reflector and the second reflector so that the light generated by the laser generator 1 passes through the center position of the opening of the rotating wheel.

7. The method for testing the rotational speed stability of a sputtering protection rotating unit for detecting high-frequency laser target shooting according to claim 5, characterized in that: In S3, the standard time width ΔT is expressed as: Among them, Δθ represents the rotation angle of the targeting wheel when the laser of the detection device passes through the hole on the targeting wheel, ω represents the rotation angular velocity of the targeting wheel, r1 represents the aperture of the hole on the targeting wheel, r0 represents the spot radius of the laser generated by the laser generator, and r represents the distance between the center of the targeting wheel and the center of the spot of the laser of the detection device on the targeting wheel.

8. The method for testing the rotational speed stability of a sputtering protection rotating unit for detecting high-frequency laser target shooting according to claim 5, characterized in that: When the target wheel rotates unstably, the following steps are further performed: Step S4: stop laser target shooting and issue an early warning to remind the target wheel that maintenance is required; S5. After maintaining the target wheel, repeat steps S1-S4 until the target wheel rotates stably.

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