Surface processing equipment

Abstract

To provide a surface processing device which can form a wafer into a uniform thickness without causing deterioration of transverse intensity.SOLUTION: A surface processing device 1 which processes a surface of an object to be processed includes: holding means 3 for holding an object to be processed; processing means 4 for processing a surface of the object to be processed held by the holding means 3; and machining and feeding means for relatively machining and feeding the holding means 3 and the processing means 4. The processing means 4 is constituted by including: an oscillator 44 for oscillating a laser beam LB1; a condenser 45 for forming the laser beam LB1 oscillated by the oscillator 44 into a plurality of beams LB2; a collimator lens 46 disposed between the oscillator 44 and the condenser 45, and for generating the laser beam LB1 into parallel light; beam strength adjustor 47 disposed between the condenser 45 and the collimator lens 46, and for adjusting the strength of the plurality of beams LB2; and rotation means 48 for rotating the condenser 45.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a surface processing apparatus for processing the surface of a workpiece. [Background technology]

[0002] A wafer with multiple devices such as ICs and LSIs formed on its surface and divided by planned dividing lines has its back surface ground using a grinding machine to form it to the desired thickness, and then is divided into individual device chips using a dicing machine and laser processing machine, and these are used in electrical devices such as mobile phones and personal computers.

[0003] The grinding device is configured to include a chuck table that holds the wafer, a grinding means that rotatably supports a grinding wheel that grinds the wafer held on the chuck table, and a grinding feed means that moves the grinding means close to the wafer and brings the grinding wheel into contact with the upper surface of the wafer, and can process the wafer to a desired thickness (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-288881 Summary of the Invention [Problem to be solved by the invention]

[0005] The grinding process performed by the grinding device described above involves pressing the processing surface of the wafer with a rotating grinding wheel, crushing it into fine particles, and so on. This leaves multiple arc-shaped grinding marks on the processing surface, which reduces the flexural strength of the chips after separation.

[0006] Furthermore, since the finished thickness of the wafer depends on the distance between the chuck table that holds the wafer and the grinding wheel, the distance is not constant due to wear of the grinding wheel and the mechanical rigidity of the grinding means disposed in the grinding device, which makes it relatively difficult to form a wafer with a uniform thickness over the entire area.Furthermore, if the wafer thickness becomes non-uniform, it is difficult to use the grinding device to partially grind the wafer and make the wafer have a uniform thickness.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and its main technical object is to provide a surface processing apparatus that can form wafers to a uniform thickness without causing a decrease in bending strength. [Means for solving the problem]

[0008] In order to solve the above-mentioned main technical problem, according to the present invention, a surface processing apparatus for processing the surface of a workpiece includes holding means for holding the workpiece, processing means for processing the surface of the workpiece held by the holding means, and processing feed means for relatively feeding the holding means and the processing means, wherein the processing means includes an oscillator for oscillating a laser beam, a condenser for forming the laser beam oscillated by the oscillator into a plurality of beams, a collimating lens disposed between the oscillator and the condenser for converting the laser beam into parallel light, a beam intensity adjuster disposed between the condenser and the collimating lens for adjusting the intensity of the plurality of beams, and a rotating means for rotating the condenser. While rotating the condenser, the focal points of the plurality of beams are positioned on the upper surface of the workpiece, and the entire area of ​​the workpiece from the outer periphery to the center is irradiated, thereby performing surface processing to reduce the thickness of the workpiece. A surface processing apparatus is provided.

[0009] The condenser is preferably a microlens array or a diffractive optical element. The beam intensity adjuster is preferably a device for adjusting the spatial intensity distribution of the beam. Furthermore, the processing means is preferably a device for positioning a focal point on a surface to be processed of a workpiece by the condenser and performing ablation processing on the surface.

[0010] A liquid storage means for filling the surface of the workpiece to be processed with liquid may be disposed between the collector and the workpiece. The surface of the workpiece may be processed by irradiating a laser beam onto the liquid filled on the surface of the workpiece by the liquid storage means to generate plasma, or by irradiating a laser beam onto the liquid filled on the surface of the workpiece by the liquid storage means to generate cavitation. Furthermore, a measuring means for measuring the thickness or height of the workpiece held by the holding means may be disposed. [Effects of the Invention]

[0011] The surface processing device of the present invention is a surface processing device that processes the surface of a workpiece, and includes holding means for holding the workpiece, processing means for processing the surface of the workpiece held by the holding means, and processing feed means for relatively feeding the holding means and the processing means, and the processing means includes an oscillator that oscillates a laser beam, a condenser that forms the laser beam oscillated by the oscillator into a plurality of beams, a collimating lens that is disposed between the oscillator and the condenser and converts the laser beam into parallel light, a beam intensity adjuster that is disposed between the condenser and the collimating lens and adjusts the intensity of the plurality of beams, and a rotating means that rotates the condenser. While rotating the condenser, the focal points of the plurality of beams are positioned on the upper surface of the workpiece, and the entire area of ​​the workpiece from the outer periphery to the center is irradiated, thereby performing surface processing to reduce the thickness of the workpiece. Therefore, when processed by a conventional grinding device, it is possible to avoid the problem of multiple arc-shaped grinding marks remaining on the grinding surface, thereby suppressing the problem of reduced flexural strength. Furthermore, since the finished thickness of the workpiece does not depend on the distance between the chuck table and the grinding wheel, as in the case of a conventional grinding device, it is easy to form the workpiece to a uniform thickness. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a perspective view showing a wafer as a workpiece. [Figure 2] 1 is an overall perspective view of a surface processing apparatus according to an embodiment of the present invention; [Figure 3]3 is a side view showing an optical system of a processing means, partly shown in cross section, arranged in the surface processing apparatus shown in FIG. 2, and an aspect of surface processing carried out by the processing means. FIG. [Figure 4] FIG. 4 is a perspective view showing an embodiment of the surface treatment shown in FIG. 3. [Figure 5] FIG. 10 is an overall perspective view of a surface processing apparatus according to another embodiment. [Figure 6] 6 is a side view showing an aspect of surface treatment carried out by a treatment means, partly shown in cross section, and a liquid storage means, which are arranged in the surface treatment apparatus shown in FIG. 5. FIG. [Figure 7] FIG. 7 is a perspective view showing an embodiment of the surface treatment shown in FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a surface processing apparatus configured based on the present invention will be described in detail with reference to the accompanying drawings.

[0014] A workpiece of this embodiment is shown in Figure 1. The workpiece is, for example, a silicon (Si) wafer 10 having a plurality of devices 12 formed on a surface 10a thereof and partitioned by planned division lines 14. A protective tape T is attached to the surface 10a of the wafer 10, and is integrated with the wafer 10 as shown in the lower part of Figure 1, to protect the surface 10a when the back surface 10b is processed by a surface processing apparatus 1 described below.

[0015] 2 shows an overall perspective view of the surface processing apparatus 1 of this embodiment. The surface processing apparatus 1 is equipped with an apparatus housing 2, and has a main body 21 having a substantially rectangular parallelepiped shape, and an upright wall 22 provided at the rear end of the main body 21 and standing in the vertical direction. The surface processing apparatus 1 is equipped with a holding means 3 disposed on a cover member 31 on the main body 21 and including a chuck table 32 that suction-holds the wafer 10, and a processing means 4 that processes the back surface 10b of the wafer 10 held by the holding means 3.

[0016] Bellows means 6a and 6b are disposed on both sides of cover member 31 in the X-axis direction indicated by arrow X in the figure. A processing feed means (not shown) that feeds chuck table 32 of holding means 3 for processing in the X-axis direction is disposed inside main body 21. By operating the processing feed means, cover member 31 is moved in the X-axis direction together with chuck table 32, contracting and extending bellows means 6a and 6b, and can be moved between a loading / unloading area at the front side in the figure where unprocessed wafer 10 is placed on chuck table 32 and a processing area at the back side in the figure where processing is performed by processing means 4.

[0017] The processing means 4 is equipped with a laser irradiation means 42. The laser irradiation means 42 has an optical system housed in a processing means housing 421, is disposed on the front surface of the upright wall 22, and is attached to a movable base 41 via a support member 43. The rear side of the movable base 41 engages with a pair of guide rails 221, 221 disposed on the upright wall 22 of the device housing 2, and is attached so as to be slidable in the Z-axis direction (up and down direction) relative to the guide rails 221, 221.

[0018] 2 includes a Z-axis moving means 7 that moves the processing means 4 along the pair of guide rails 221 in the direction indicated by the arrow Z in the figure. The Z-axis moving means 7 includes a male threaded rod 71 that is disposed on the front side of the upright wall 22 and extends in the vertical direction. The upper and lower ends of the male threaded rod 71 are rotatably supported by the upright wall 22. A pulse motor 72 is disposed at the upper end of the male threaded rod 71 as a drive source for rotating the male threaded rod 71, and the output shaft of the pulse motor 72 is connected to the male threaded rod 71. A threaded connecting portion (not shown) is formed on the rear surface of the movable base 41, and a female threaded hole extending in the vertical direction is formed in the connecting portion, into which the male threaded rod 71 is screwed. Such Z-axis moving means 7 can lower the processing means 4 together with the moving base 41 by rotating the pulse motor 72 forward, and can raise the processing means 4 together with the moving base 41 by rotating the pulse motor 74 backward.

[0019] The surface processing apparatus 1 of this embodiment is provided with a measuring means 5 for measuring the thickness (or height) of the wafer 10 held on the chuck table 32 of the holding means 3. The measuring means 5 is disposed on the main body 21 of the apparatus housing 2 at a position adjacent in the Y-axis direction to the region where the chuck table 32 moves in the X-axis direction, and is disposed on a sidewall 23 formed along the X-axis direction. The measuring means 5 is driven by a moving means (not shown) disposed inside the sidewall 23 and configured to be movable along a sliding groove 23a of the sidewall 23 formed in the direction indicated by X1. The type of the measuring means 5 is not particularly limited, but for example, it may be a non-contact thickness measuring means that irradiates a measurement laser beam LB0 having a predetermined wavelength range from the tip 51 of the extension arm 52, detects return light reflected by the back surface 10b and front surface 10a of the wafer 10, and measures the thickness (or height) of the wafer 10 by Fourier transforming the spectral interference waveform based on the return light. The above-mentioned laser irradiation means 42, processing feed means (not shown), measurement means 5, Z-axis movement means, etc. are connected to control means (not shown).

[0020] 2 and 3, the optical system of the laser irradiation means 42 constituting the processing means 4 of this embodiment will be described in more detail. The laser irradiation means 42 includes an oscillator 44 that oscillates a laser beam LB1, a condenser 45 that forms the laser beam LB1 oscillated by the oscillator 44 into multiple beams LB2, a collimating lens 46 that is disposed between the oscillator 44 and the condenser 45 and converts the laser beam LB1 into parallel light, a beam intensity adjuster 47 that is disposed between the condenser 45 and the collimating lens 46 and adjusts the intensity of the multiple beams LB2, and a rotation means 48 that rotates the condenser 45 to rotate the multiple beams LB2 in the direction indicated by arrow R1. The optical system of the laser irradiation means 42 described above is contained in a processing means housing 421 that is supported by a support member 43.

[0021] The condenser 45 can be, for example, a microlens array, which is an optical lens consisting of a plurality of micron-order minute lenses arranged in series, or a diffractive optical element (DOE) that spatially splits laser light by utilizing the diffraction phenomenon of light. According to the laser irradiation means 42, the condenser 45 forms the laser beam LB1 emitted from the oscillator 44 into multiple beams LB2, which are then dispersed and focused (see P1 to P5 in the figure) on a predetermined irradiation area for irradiation. Note that in FIG. 3, for convenience of explanation, the focusing points of the multiple beams LB2 formed by the condenser 45 are simplified and indicated by P1 to P5. However, in reality, the beams LB2 are dispersed into any number of beams, for example, several hundred beams, within the predetermined irradiation area. Furthermore, the condenser 45 is not limited to being composed solely of the microlens array or diffractive optical element, but may also be configured in combination with a separate focusing lens, aspherical lens, or the like.

[0022] For example, a hollow motor is used as the rotation means 48. The hollow motor is formed into an annular shape with an encoder disposed on the outer periphery of a hollow shaft, and holds the above-mentioned condenser 45 in the space at the center of the shaft, rotating the condenser 45 at high speed (for example, 50,000 rpm or less), thereby rotating the multiple beams LB2 irradiated from the condenser 45 in the direction indicated by arrow R1.

[0023] The beam intensity adjuster 47 can be, for example, a spatial light modulator (LCOS) or a digital micromirror device (DMD). The laser beam LB1 that has passed through the collimator lens 47 is adjusted by the beam intensity adjuster 47, and the spatial intensity distribution of the multiple beams LB2 that are irradiated from the condenser 45 can be adjusted to a desired spatial intensity distribution. Note that although the illustrated embodiment shows an example in which a transmissive spatial light modulator (LCOS) is used, a reflective spatial light modulator can also be used.

[0024] 3, the laser irradiation means 42 of this embodiment positions and irradiates the back surface 10b of the wafer 10 with focal points (e.g., P1 to P5) of a plurality of beams LB2 irradiated from a condenser 45 on the back surface 10b of the wafer 10, thereby performing ablation processing on the back surface 10b of the wafer 10. Processing conditions when surface processing is performed by the laser irradiation means 42 of this embodiment are, for example, as follows. Wavelength: 355nm Pulse width: 10ps Repetition frequency: 1MHz Average power: 10W Numerical aperture (NA): 0.2

[0025] The procedure for processing the back surface 10b of the wafer 10 using the surface processing apparatus 1 will now be described in more detail.

[0026] 2, once the holding means 3 is positioned in the loading / unloading area, the back surface 10b of the wafer 10 integrated with the protective tape T is placed on the chuck table 32 with the protective tape T side facing upward and held by suction. Next, the processing feed means (not shown) is operated to move the chuck table 32 toward the processing area in the X-axis direction, and the outer peripheral edge of the wafer 10 is positioned at a position where the multiple beams LB2 are irradiated from the above-mentioned condenser 45 of the processing means 4.

[0027] Next, the oscillator 44, beam intensity adjuster 47, rotation means 48, and Z-axis moving means 7 are operated to position the focal points (P1 to P5) of the multiple beams LB2 irradiated from the laser irradiation means 42 on the back surface 10b of the wafer 10 and irradiate the same, as shown in Figures 3 and 4, and the multiple beams LB2 are rotated in the direction indicated by arrow R1, and the chuck table 32 is moved in the X-axis direction while rotating in the direction indicated by arrow R2, thereby performing the surface processing until the multiple beams LB2 reach the center O of the wafer 10.

[0028] By performing the ablation process by the above-described surface treatment on the back surface 10b of the wafer 10, the area S on the back surface 10b irradiated with the multiple beams LB2 gradually expands, thereby reducing the thickness of the wafer 10. As described above, the surface treatment apparatus 1 of this embodiment is provided with the measurement means 5, and the extension arm 52 of the measurement means 5 is moved in the direction indicated by X1 along the sliding portion 23a of the side wall portion 23 to position the tip 51 above a predetermined position from the center O of the wafer 10, and a measurement laser beam LB0 is irradiated. The measurement laser beam LB0 detects return light reflected by the back surface 10b and front surface 10a of the wafer 10, and the spectral interference waveform based on the return light is Fourier transformed to measure the thickness of the wafer 10 at the predetermined position. This measurement is performed at multiple positions on the wafer 10 defined by X and Y coordinate positions while moving the extension arm 52 and rotating the chuck table 32, thereby measuring the thickness in detail over the entire area of ​​the wafer 10. When measuring the thickness of the wafer 10 with the measurement means 5, it is preferable to stop the surface treatment by the laser irradiation means 42. A control means (not shown) determines whether the thickness of the wafer 10 detected by the measurement is the desired thickness. If the thickness is not the desired thickness, the surface treatment of the wafer 10 is performed by the laser irradiation means 42 until the desired thickness is reached. A cleaning water injection means for injecting high-pressure cleaning water onto the area irradiated with the measurement laser beam LB0 from the measurement means 5 may be provided, and the thickness measurement may be performed while cleaning the area of ​​the wafer 10 whose thickness is to be measured.

[0029] According to this embodiment, the rotation means 48 rotates the multiple beams LB2 emitted from the condenser 45 in the direction indicated by R1, and rotates the wafer 10 together with the chuck table 32 in the direction indicated by R2. This uniformly removes the back surface 10b of the wafer 10 in the area irradiated with the multiple beams LB2. This prevents the formation of multiple arc-shaped grinding marks on the ground surface, which would occur if the wafer were ground using a conventional grinding device, thereby suppressing the problem of reduced flexural strength. Furthermore, as described above, the finished thickness of the wafer 10 does not depend on the distance between the chuck table and the grinding wheel, as in the case of conventional grinding devices, and the wafer 10 can be easily formed to a uniform thickness. Furthermore, by having the above-described configuration, it is possible to process the surface of the wafer 10 (back surface 10b) partially while moving the chuck table 32, positioning the multiple beams LB2 at the desired position on the wafer 10, stopping the movement of the chuck table 32, stopping the rotation of the collector 45, etc., thereby processing the surface of the wafer 10 into the desired shape.

[0030] The present invention is not limited to the processing apparatus 1 of the above-described embodiment. Other embodiments will be described with reference to FIGS.

[0031] 5 shows a surface processing apparatus 1' according to another embodiment of the present invention. The surface processing apparatus 1' has substantially the same configuration as the above-described surface processing apparatus 1, and the same components are assigned the same numbers and detailed descriptions thereof are omitted.

[0032] In addition to the components of the surface processing apparatus 1 described above, the surface processing apparatus 1′ of this embodiment includes a liquid storage means 8, as shown in FIG. 5. The liquid storage means 8 is, for example, a concave container having an opening on the lower side. The liquid storage means 8 includes a cylindrical frame member 81 and a transparent plate member 82 that closes the upper surface of the frame member 81 and transmits the multiple beams LB2 irradiated from the condenser 45 of the laser irradiation means 42. The plate member 82 may be made of, for example, a glass plate or an acrylic plate. The liquid storage means 8 is detachably disposed on the cover member 31′ of the holding means 3′. When the wafer 10 is placed on the chuck table 32′ while being held by suction, the liquid storage means 8 is disposed between the condenser 45 and the wafer 10 held on the chuck table 32′. As shown in FIGS. 6 and 7, in this embodiment, the cover member 31′ is provided with a liquid supply port 31a′ for supplying the liquid W (e.g., pure water) stored inside the liquid storage means 8 and a liquid discharge port 31b′ for discharging the liquid W. Liquid W, pumped from a liquid supply means (not shown), is supplied into the liquid storage means 8 through liquid supply port 31a', filling the interior of the liquid storage means 8 with liquid W, and then appropriately discharged through liquid discharge port 31b'. Note that liquid supply port 31a' and liquid discharge port 31b' are not necessarily limited to being disposed on the cover member 31', and may be disposed, for example, on the side surface of frame member 81 of liquid storage means 8. Furthermore, the liquid storage means 8 and cover member 31' are not necessarily required to be in tight contact with each other. An appropriate gap may be provided between the liquid storage means 8 and cover member 31', and the liquid W may be discharged through the gap.

[0033] The surface processing performed by the surface processing apparatus 1' is carried out in substantially the same procedure as that of the surface processing apparatus 1 described above. More specifically, with the holding means 3' positioned in the loading / unloading area, before placing the liquid storage means 8 on the cover member 31', the back surface 10b of the wafer 10, which has a protective tape T attached to its front surface 10a and is integrated with the back surface 10b, is placed on the chuck table 32' with the protective tape T side facing upward and held by suction. Next, the liquid storage means 8 is placed on the cover member 31', and liquid W is supplied from the liquid supply port 31a' to fill the liquid storage means 8 with liquid W. Next, the processing feed means (not shown) is operated to move the chuck table 32' toward the processing area in the X-axis direction, and the outer periphery of the wafer 10 is positioned at a position where multiple beams LB2 are irradiated from the condenser 45 of the laser irradiation means 42, so that the liquid storage means 8 is disposed between the condenser 45 and the wafer 10.

[0034] Next, the oscillator 44, beam intensity adjuster 47, rotation means 48, and Z-axis moving means 7 are operated to position and irradiate the focal points (P1-P5) of the multiple beams LB2 irradiated from the laser irradiation means 42 on the back surface 10b of the wafer 10, as shown in FIGS. 6 and 7 , and the multiple beams LB2 are rotated in the direction indicated by arrow R1, while the chuck table 32' is moved in the X-axis direction while rotating in the direction indicated by arrow R2, thereby performing the surface processing until the multiple beams LB2 reach the center O of the wafer 10. During this process, liquid W is supplied into the liquid storage means 8 from the liquid supply port 31a' and discharged from the liquid discharge port 31b'. As a result, processing debris and the like generated by the processing performed in the surface processing are removed by the liquid W.

[0035] By performing the ablation process using the surface treatment described above on the back surface 10b of the wafer 10, the area S on the back surface 10b irradiated with the multiple beams LB2 gradually expands, reducing the thickness of the wafer 10. In the surface treatment apparatus 1′, since the liquid storage means 8 is provided, it is preferable to measure the thickness of the wafer 10 using the measurement means 5 without the liquid storage means 8. The measurement means 5 measures the thickness of the wafer 10 at multiple positions defined by X and Y coordinate positions on the wafer 10, measuring the thickness in detail over the entire area of ​​the wafer 10. A control means (not shown) determines whether the thickness of the wafer 10 detected by the measurement is the desired thickness. If the desired thickness is not achieved, the liquid storage means 8 is replaced again, and the processing of the wafer 10 using the laser irradiation means 42 is continued until the desired thickness is achieved.

[0036] By using the above-mentioned liquid storage means 8 to fill the back surface 10b of the wafer 10 to be processed with liquid W, not only can processing debris and the like generated by processing be quickly removed as described above, but it is also possible to realize the following processing.

[0037] In the above-described surface treatment, the focal points (P1 to P5) of the multiple beams LB2 are positioned on the back surface 10b of the wafer 10 to perform ablation processing. However, for example, the focal points (P1 to P5) may be slightly spaced (e.g., less than 1 mm, preferably 0.5 mm) from the back surface 10b of the wafer 10 to irradiate the multiple beams LB2. This converts the liquid W into plasma near the back surface 10b of the wafer 10, and not only performs the ablation processing described above, but also performs plasma processing on the back surface 10b. This allows for multiple processing on the back surface 10b, resulting in more uniform processing. Furthermore, the focal points (P1 to P5) of the multiple beams LB2 may be spaced (e.g., 1 mm or more, preferably 1 mm) from the back surface 10b of the wafer 10 to generate cavitation near the focal points, and the back surface 10b may be processed by the impact pressure generated when the cavitation bubbles collapse.

[0038] The surface processing apparatus 1' described above can also achieve the same effects as those achieved by the surface processing apparatus 1 described above, and furthermore, can convert the liquid W into plasma near the back surface 10b of the wafer 10 and perform surface processing using the plasma, or can generate cavitation near the back surface 10b and perform surface processing using the impact pressure when the bubbles disappear, thereby making it possible to process the back surface 10b more uniformly.

[0039] It is preferable that the above-mentioned ablation processing, plasma processing, and cavitation processing are performed in combination, rather than individually, on the back surface 10b of the wafer 10. However, since the processing conditions (focusing point positions of the multiple beams LB2, average output, etc.) for optimally performing each of the ablation processing, plasma processing, and cavitation processing are different, it is preferable to determine the optimal processing conditions for processing the wafer 10 to a more uniform thickness in advance through simulations, experiments, etc. [Explanation of symbols]

[0040] 1, 1': Surface processing device 2: Device housing 21: Main body 22: Upright wall 23: Side wall 23a: sliding part 3: Holding means 31, 31': Cover member 31a':Liquid supply port 31b':Liquid outlet 32, 32': Chuck table 4: Processing means 41: Mobile base 42: Laser irradiation means 43: Support member 44: Oscillator 45: Concentrator 46: Collimating lens 47: Beam intensity adjuster 48: Rotation means 5: Measurement methods 51:Tip 52: Extension arm 6a, 6b: bellows members 7: Z-axis movement means 71: Male threaded rod 72: Pulse motor 8: Liquid storage means 81: Frame member 82: Plate member 10: Wafer 10a: surface 10b: Back side 12: Device 14: Planned division line LB0: Laser beam for measurement LB1: Laser beam LB2: Multiple beams W:Liquid (pure water)

Claims

1. A surface processing apparatus for processing a surface of a workpiece, The method includes holding means for holding a workpiece, processing means for processing a surface of the workpiece held by the holding means, and processing feed means for relatively feeding the holding means and the processing means, the processing means comprises an oscillator that oscillates a laser beam, a condenser that forms the laser beam oscillated by the oscillator into a plurality of beams, a collimator lens that is disposed between the oscillator and the condenser and converts the laser beam into parallel light, a beam intensity adjuster that is disposed between the condenser and the collimator lens and adjusts the intensities of the plurality of beams, and a rotating means that rotates the condenser; A surface processing apparatus that performs surface processing to reduce the thickness of a workpiece by rotating the condenser, positioning the focal points of the multiple beams on the top surface of the workpiece, and irradiating the entire area of ​​the workpiece from the outer edge to the center.

2. 2. The surface processing apparatus according to claim 1, wherein the condenser is a microlens array or a diffractive optical element.

3. 3. The surface processing apparatus according to claim 1, wherein the beam intensity adjuster adjusts the spatial intensity distribution of the beam.

4. 4. The surface processing apparatus according to claim 1, wherein the processing means positions a focal point on the surface of the workpiece to be processed by the condenser, and performs ablation processing on the surface.

5. 5. A surface treatment apparatus according to claim 1, further comprising a liquid reservoir means disposed between the light collector and the workpiece for filling the surface of the workpiece with liquid.

6. 6. The surface treatment apparatus according to claim 5, wherein the surface of the workpiece is treated with plasma generated by irradiating a laser beam onto the liquid filled on the surface of the workpiece by the liquid reservoir means.

7. 7. The surface treatment apparatus according to claim 5, wherein the surface of the workpiece is treated by cavitation generated by irradiating a laser beam onto the liquid filled on the surface of the workpiece by the liquid reservoir means.

8. 8. The surface processing apparatus according to claim 1, further comprising a measuring means for measuring the thickness or height of the workpiece held by the holding means.

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