TWI590900B - Sapphire substrate processing methods - Google Patents

Description

Sapphire substrate processing method Field of invention

The present invention relates to a sapphire that irradiates a laser beam along a predetermined dividing line of a sapphire substrate used as a substrate for an optical element wafer or the like to form a modified layer along the dividing line in the interior of the sapphire substrate. The processing method of the substrate.

Background of the invention

In the optical element manufacturing step, the surface layer of the sapphire substrate having a substantially circular plate shape has an optical element layer made of a gallium nitride-based compound semiconductor, and is formed in a plurality of fields divided by a plurality of predetermined dividing lines formed in a lattice shape. An optical element such as a light-emitting diode or a laser diode is formed to constitute an optical element wafer. Further, each of the optical elements is manufactured by dividing the optical element wafer along the dividing line.

As a method of dividing the optical element wafer along the dividing line, it is proposed to illuminate the sapphire substrate constituting the optical element wafer, and to illuminate the condensing point inside the laser beam having a transparent wavelength along the dividing line. In the interior of the sapphire substrate, the reforming layer which is the starting point of the break is continuously formed along the predetermined dividing line, and the external force is applied along the dividing line on which the reforming layer which is the starting point of the breaking is formed, and the crystal is divided. Round method (for example, refer to Patent Document 1).

[First technical literature]

[Patent Literature]

[Patent Document 1] Patent No. 3408805

Summary of invention

Further, even if the processing conditions for forming the reforming layer which is the starting point of the breaking along the dividing line in the interior of the sapphire substrate are set, the production amount of the sapphire substrate is different, and even if the manufacturers of the sapphire substrate are different, the same size is the same. When the thickness of the sapphire substrate is processed under the same conditions, there is a problem that the modified layer is insufficient, and the optical element is damaged by the deviation from the planned dividing line and the occurrence of cracks. That is, in the sapphire substrate at the stage of growing Al ₂ O ₃ , crystal defects (oxygen defects) occur, so even in the case of sapphire substrates of the same size and the same thickness, when the production batches are different from each other, the sapphire substrate is required. The inside is formed with an appropriate reforming layer as a breaking starting point along the dividing line, and it is desirable to set the processing conditions each time the sapphire substrate is used.

The present invention has been made in view of the above circumstances, and a main technical problem thereof is to provide a method for processing a sapphire substrate which can form a suitable modified layer even if a sapphire substrate having a different manufacturer size is manufactured.

In order to solve the above-mentioned main technical problems, according to the present invention, a laser processing method is provided in which a sapphire substrate is irradiated with a pulsed laser beam having a wavelength of transparency to internally illuminate a light collecting point and is irradiated along a dividing line to a sapphire. A method for processing a sapphire substrate that forms a modified layer as a breaking starting point along a predetermined dividing line, wherein the laser processing method includes: a processing condition setting step corresponding to a sapphire substrate Setting at least two types of processing conditions; the determining condition setting step is for determining a sapphire substrate on which at least two types of processing conditions are set; and the processing condition determining step is based on the determination condition set by the determination condition setting step, Determining a sapphire substrate, determining one processing condition from at least two types of processing conditions set in the processing condition setting step of the determined sapphire substrate; and modifying the layer forming step according to the processing condition determining step The processing conditions are such that the light collecting point of the laser light is positioned inside the sapphire substrate, and is irradiated along the planned dividing line, and a modified layer which becomes a breaking starting point is formed inside the sapphire substrate along the dividing line.

The judging condition setting step is to irradiate the laser light that does not output the sapphire substrate to the inside of the sapphire substrate, and to obtain the laser light outputting the limit of the reaction light emission according to the reaction light emitted at this time. Set the judgment conditions.

The method for processing a sapphire substrate according to the present invention includes a processing condition setting step of setting at least two types of processing conditions corresponding to the characteristics of the sapphire substrate, and a determination condition setting step for determining a sapphire substrate on which at least two types of processing conditions are set, The sapphire substrate is determined based on the determination condition set by the determination condition setting step, and the processing conditions for determining one processing condition are determined from at least two types of processing conditions set in the processing condition setting step of the determined sapphire substrate. The step and the processing conditions determined in the processing condition determining step, the spot light of the laser light is positioned inside the sapphire substrate, and is irradiated along the dividing line, and is formed inside the sapphire substrate along the dividing line. Deterioration of the starting point The reforming layer forming step of the layer is performed because the reforming layer forming step is performed under the processing conditions set corresponding to the characteristics of the sapphire substrate, so that the modified layer formed by the insufficient output of the pulsed laser light is insufficient, The output of the pulsed laser light is excessive and the sapphire substrate is deviated from the dividing line and cracks occur.

Simple illustration

Fig. 1 is a perspective view of a laser processing apparatus for carrying out a method of processing a sapphire substrate of the present invention.

Fig. 2 is a block diagram schematically showing the configuration of a laser beam irradiation mechanism equipped in the laser processing apparatus shown in Fig. 1.

3(a) to 3(b) are perspective views of the optical element wafer processed by the processing method of the sapphire substrate of the present invention.

Fig. 4 is a perspective view showing a state in which the optical element wafer shown in Fig. 3 is attached to a protective tape attached to the annular frame.

Fig. 5 is an explanatory view showing a setting condition of a discrimination condition of a processing method of the sapphire substrate of the present invention.

6(a) to 6(b) are explanatory views of the reforming layer forming step of the processing method of the sapphire substrate of the present invention.

Detailed description of the preferred embodiment

[Formation for implementing the invention]

Hereinafter, preferred embodiments of the laser processing method for wafers of the present invention will be described in further detail with reference to the accompanying drawings.

Figure 1 shows the processing of the sapphire substrate for carrying out the invention. A perspective view of a laser processing apparatus of the method. The laser processing apparatus 1 shown in Fig. 1 is provided with a stationary machine 2, and is disposed in the stationary machine table 2 to be held in the machining feed direction (X-axis direction) indicated by an arrow X. The chuck mechanism 3 can be disposed in the laser beam irradiation unit support mechanism 4 of the stationary machine 2 so as to be movable in the calculation direction (Y-axis direction) indicated by the arrow Y orthogonal to the X-axis direction, and The laser beam irradiation unit 5 of the laser beam irradiation unit support mechanism 4 is disposed so as to be movable in the direction (Z-axis direction) of the light-collecting point position indicated by the arrow Z.

The chuck stage mechanism 3 includes a pair of guide rails 31 and 31 that are disposed in parallel with the X-axis direction on the stationary base 2, and are disposed on the guide rails 31 and 31 so as to be movable in the X-axis direction. The first slide block 32 is disposed on the first slide block 33 that is disposed on the first slide block 32 so as to be movable in the calculation direction indicated by the arrow Y, and is supported by the second slide block 33 by the cylindrical member 34. The upper cover 35 and the chuck table 36 as a workpiece holding mechanism. The chuck table 36 is provided with an adsorption chuck 361 formed of a porous material, and is formed on the upper surface (holding surface) of the adsorption chuck 361 by a suction mechanism of a pattern, for example, in the form of a disk. Semiconductor wafers. The chuck table 36 thus configured is rotated by a pulse motor (not shown) disposed in the cylindrical member 34. Further, a clamp 362 for fixing the annular frame, which will be described later, is disposed on the chuck table 36.

The first slide block 32 is provided on the lower surface thereof with a pair of guided grooves 321 and 321 which are fitted to the pair of guide rails 31 and 31, and a pair of guide rails 322 which are formed in parallel on the Y-axis direction. 322. The first slider 32 thus configured is fitted to the pair of guides by the guided grooves 321 and 321 The rails 31 and 31 are configured to be movable in the X-axis direction along the pair of guide rails 31 and 31. The chuck mechanism 3 of the embodiment of the drawings has a machining feed mechanism 37 for moving the first slider 32 in the X-axis direction along the pair of guide rails 31 and 31. The machining feed mechanism 37 includes a male screw 371 disposed in parallel between the pair of guide rails 31 and 31, and a drive source such as a pulse motor 372 for rotationally driving the male screw 371. The male screw 371 has one end rotatably supported by a bearing block 373 fixed to the stationary base 2, and the other end of which is coupled to an output shaft of the pulse motor 372. Further, the male screw 371 is screwed to the through female screw hole formed in the female nut of the unillustrated female screw projecting from the lower portion of the central portion of the first sliding block 32. Therefore, the male screw 371 is driven forward and reverse by the pulse motor 372, so that the first slider 32 can be moved in the X-axis direction along the guide rails 31 and 31.

The second sliding block 33 is provided on the lower surface thereof with a pair of guided grooves 331 and 331 which are fitted to a pair of guide rails 322 and 322 provided on the upper surface of the first sliding block 32, and the guided grooves 331 and 331 are provided. The pair of guide rails 322 and 322 are fitted to each other, and the configuration is movable in the calculated transport direction indicated by the arrow Y. The chuck mechanism 3 of the embodiment shown in the drawings has a first calculation transfer mechanism 38 for moving the second slider 33 along the one of the first sliders 32 to the guide rails 322 and 322 in the Y-axis direction. The first calculation transport mechanism 38 includes a male screw 381 disposed in parallel between the pair of guide rails 322 and 322, and a drive source such as a pulse motor 382 for rotationally driving the male screw 381. The male screw 381 is rotatably supported at one end by a bearing block 383 fixed to the upper surface of the first slider 32, and the other end of the male screw 381 is coupled to an output shaft of the pulse motor 382. Moreover, the male screw 381 is screwed into the protruding arrangement The female screw hole of the unillustrated female screw block under the central portion of the second sliding block 33 passes through the female screw hole. Therefore, the male screw 381 is driven forward and reverse by the pulse motor 382, so that the second slider 33 can be moved in the Y-axis direction along the guide rails 322 and 322.

The laser beam irradiation unit support mechanism 4 includes a pair of guide rails 41 and 41 disposed in parallel with the calculated transport direction indicated by the arrow Y on the stationary machine table 2, and is disposed to be movable in the Y-axis direction. The movable support base 42 on the guide rails 41, 41. The movable support base 42 is configured by a movement support portion 421 movably disposed on the guide rails 41 and 41 and a mounting portion 422 attached to the movement support portion 421. The mounting portion 422 is provided with a pair of guide rails 423 and 423 extending in the Z-axis direction in parallel on one side surface. The laser beam irradiation unit support mechanism 4 of the embodiment shown in the drawing includes a second calculation transport mechanism 43 for moving the movable support base 42 in the Y-axis direction along the pair of guide rails 41 and 41. The second calculation transport mechanism 43 includes a male screw 431 disposed in parallel between the pair of guide rails 41 and 41, and a drive source such as a pulse motor 432 for rotationally driving the male screw 431. One end of the male screw 431 is rotatably supported by a bearing block (not shown) fixed to the stationary machine 2, and the other end of the male screw 431 is coupled to an output shaft of the pulse motor 432. Further, the male screw 431 is screwed to a female screw hole formed in a female nut which is formed on a lower surface of a central portion of the movement support portion 421 which constitutes the movable support base 42. Therefore, the male screw 431 is driven forward and reverse by the pulse motor 432, and the movable support base 42 can be moved in the Y-axis direction along the guide rails 41 and 41.

The laser beam irradiation unit 5 of the embodiment shown in the figure is provided with a unit branch The holder 51 and the laser beam irradiation mechanism 6 on which the unit holder 51 is mounted. The unit holder 51 is provided with a pair of guided grooves 511 and 511 slidably fitted to a pair of guide rails 423 and 423 provided in the mounting unit 422, and the guided grooves 511 and 511 are fitted to the above. The guide rails 423, 423 are guided to be movable in the Z-axis direction.

The illustrated laser beam irradiation unit 5 is provided with a light collection point position adjustment mechanism 53 for moving the unit holder 51 in the Z-axis direction along the pair of guide rails 423 and 423. The light collecting point position adjusting mechanism 53 includes a male screw (not shown) disposed between the pair of guiding rails 423 and 423, and a driving source such as a pulse motor 532 for rotationally driving the male screw, by using a pulse motor The 532 is rotated forward and reversely to drive a male screw (not shown), and the unit holder 51 and the laser beam irradiation unit 6 are moved in the Z-axis direction along the guide rails 423 and 423. Further, in the illustrated embodiment, the laser irradiation light mechanism 6 is moved upward by the forward rotation drive pulse motor 532, and the laser irradiation light mechanism 6 is moved downward by the reverse rotation drive pulse motor 532.

The illustrated laser beam irradiation mechanism 6 includes a cylindrical casing 61 that is fixed to the unit holder 51 and extends substantially horizontally. The laser light irradiation unit 6 will be described with reference to Fig. 2 .

The illustrated laser beam irradiation mechanism 6 includes a pulsed laser beam oscillating mechanism 62 disposed in the casing 61, and an output adjustment for adjusting the output of the pulsed laser beam oscillated by the pulsed laser ray oscillating mechanism 62. The mechanism 63 adjusts the output of the pulsed laser beam to the holding surface on the upper surface of the chuck table 36 by the output adjustment mechanism 63, and the direction changing mirror 64 is used by the direction changing mirror 64. Directionally transformed pulse The laser beam is collected by the laser beam and is incident on the collecting mirror 65 of the workpiece W held by the chuck table 36.

The pulsed laser beam oscillating mechanism 62 is composed of a pulsed laser ray oscillator 621 that oscillates, for example, a pulsed laser beam having a wavelength of 532 nm, and a reverse frequency setting mechanism 622 attached thereto. The output adjustment mechanism 63 adjusts the output of the pulsed laser light oscillated by the pulsed laser ray oscillating mechanism 62 to a predetermined output. The pulsed laser beam oscillating mechanism 62 and the output adjusting mechanism 63 are controlled by a control mechanism to be described later.

The description will be continued with reference to Fig. 2, in which the laser processing apparatus 1 is provided with a beam splitter 66 disposed between the direction changing mirror 64 and the collecting mirror 65. The beam splitter 66 has a function of passing light of a wavelength oscillated by the pulsed laser ray oscillating mechanism 62, but light of other wavelengths is reflected. Therefore, the beam splitter 66 reflects light that is emitted by irradiating the pulsed laser beam to the workpiece W held by the chuck table 36.

Further, it is also possible to illuminate an irradiation field of pulsed laser light that is irradiated by the collecting mirror 65 by an illumination mechanism composed of white light.

The laser processing apparatus 1 according to the embodiment of the present invention includes a cut filter 67 that blocks light of a predetermined range of reflected light reflected by the dichroic mirror 66, and captures light passing through the cut filter 67. And an imaging mechanism 68 for imaging. The cut filter 67 blocks light of 510 to 550 nm in the wavelength range of the pulsed laser light oscillated by the pulsed laser ray oscillator 621, and passes light of a wavelength other than the wavelength. The imaging mechanism 68 captures the light that has been cut by the filter 67 and images the captured image signal to the control mechanism. 7. The control unit 7 determines, based on the image signal from the image pickup unit 68, the reaction light that is emitted by the pulsed laser light to be irradiated onto the workpiece W held by the chuck table 36. The control unit 7 is provided with a memory that stores at least two types of processing conditions that are set to correspond to characteristics of a sapphire substrate that constitutes an optical element wafer to be described later, and a judgment condition for determining a sapphire substrate on which at least two types of processing conditions are set. Body 71. Further, the control unit 7 receives a detection signal from the imaging unit 68 and an alignment unit 8 to be described later, inputs processing conditions and the like from the input unit 70, and outputs a control signal to the pulsed laser ray oscillator 621 or repeatedly. The frequency setting mechanism 622 or the output adjustment mechanism 63, the monitor 9, and the like.

Returning to Fig. 1, the laser processing apparatus 1 shown in the drawing is provided with an alignment of the processing area in which the front end portion of the casing 61 is disposed and which is to be subjected to laser processing by the above-described laser beam irradiation mechanism 6. Agency 8. The alignment mechanism 8 is constituted by an optical mechanism such as a microscope or a CCD camera, and sends the imaged image signal to the control unit 7.

Next, a description will be given of a method of processing a sapphire substrate which is carried out using the above-described laser processing apparatus 1.

3(a) and 3(b) are a perspective view showing an optical element wafer processed by the method for processing a sapphire substrate of the present invention, and a cross-sectional view showing an enlarged main portion. The optical element wafer 10 shown in FIGS. 3(a) and 3(b) is, for example, a surface 11a of a sapphire substrate 11 having a diameter of 150 mm and a thickness of 100 μm, and an n-type nitride semiconductor layer 121 is laminated with a thickness of, for example, 5 μm. And an optical element layer (epitaxial layer) 12 composed of the p-type nitride semiconductor layer 122. Further, the optical element layer (the epitaxial layer) 12 is formed by dividing the predetermined line 13 by a plurality of lattices. In the plural domain of division, an optical element 14 having a light-emitting diode, a laser diode, or the like is formed.

Hereinafter, a processing method of forming a sapphire substrate which is a modified layer which is a breaking starting point along the dividing line 13 in the inside of the sapphire substrate 11 constituting the optical element wafer 10 by the laser processing apparatus 1 will be described.

Further, the sapphire substrate 11 constituting the optical element wafer 10 is manufactured by two production lots (A batch, B batch). For the sapphire substrates manufactured in two production batches (A batch, B batch), the optimum processing conditions for forming the modified layer inside the sapphire substrate are experimentally determined, and each processing condition is set first (processing condition setting step). ).

For example, the first processing conditions for the sapphire substrate manufactured in batches A are set as follows.

Laser light wavelength: 532nm

Repeat frequency: 45kHz

Average output: 0.13W

Spot spot diameter: φ1μm

Processing feed rate: 360mm / sec

Further, the second processing conditions for the sapphire substrate manufactured in batch B were set as follows.

Laser light wavelength: 532nm

Repeat frequency: 45kHz

Average output: 0.15W

Spot spot diameter: φ1μm

Processing feed rate: 360mm / sec

The first processing condition and the second processing condition set as described above are first stored in the memory 71 of the control unit 7.

Further, a determination condition setting step for judging the sapphire substrate produced in the above-mentioned A batch or the sapphire substrate manufactured in the above-mentioned B batch is carried out. The determination condition setting step is to irradiate the laser light that cannot output the sapphire substrate to the inside of the sapphire substrate, and to obtain the laser light outputting the limit of the reaction light emission according to the reaction light emitted at this time, and Set the judgment conditions. According to the experiment of the inventors of the present invention, the sapphire substrate produced in batch A was judged by the output of the laser light which is observed by the monitor 9 to limit the light emission of the reaction light to 0.025 W. On the other hand, the sapphire substrate manufactured in batch B was judged by the output of the laser light which is observed by the monitor 9 to limit the light emission of the reaction light to 0.035 W. Therefore, by setting the output of the laser light output to a laser light output of 0.025 W at the limit of the sapphire substrate manufactured in batch A and a laser light output of 0.035 W at the boundary of the sapphire substrate manufactured in batch B, When the reaction light was emitted, it was judged that the sapphire substrate was mass-produced in A, and when the reaction light could not be confirmed, it was judged that the sapphire substrate was mass-produced in B. When it is required to determine the laser light output of the sapphire substrate manufactured in batch A and the sapphire substrate manufactured in batch B, the determination conditions are set as follows, and are first stored in the memory 71 of the control unit 7.

Analyzing conditions:

Laser light wavelength: 532nm

Repeat frequency: 45kHz

Average output: 0.03W

Spot spot diameter: ψ1μm

Processing feed rate: 360mm / sec

In this way, the first processing conditions for the sapphire substrate manufactured in batch A and the second processing conditions for the sapphire substrate manufactured in batch B are set, and the sapphire substrate manufactured in batch A and the batch manufactured in B are set. The determination condition of the sapphire substrate is such that the first processing condition and the second processing condition and the determination condition are stored in the memory 71 of the control unit 7, and the laser processing unit 1 processes the optical element crystal shown in FIG. 3 as follows. Round 10.

First, as shown in Fig. 4, the surface 10a of the optical element wafer 10 is attached to the surface of the adhesive tape T mounted on the annular frame F (wafer fixing step). Therefore, the optical element wafer 10 attached to the surface of the adhesive tape T is such that the inner surface 11b of the sapphire substrate 11 is on the upper side.

When the wafer attaching step is performed, the adhesive tape T side of the photosensor wafer 10 is placed on the chuck table 36 of the laser processing apparatus shown in FIG. Then, the optical element wafer 10 is sucked and held by the adhesive tape T by the suction mechanism T (not shown) (wafer holding step). Therefore, the optical element wafer 10 held by the chuck table 36 has the inner surface 11b as the upper side.

As described above, the chuck table 36 that sucks and holds the optical element wafer 10 is positioned directly under the alignment mechanism 8 by the processing feed mechanism 37. When the chuck table 36 is positioned directly under the alignment mechanism 8, the alignment operation in the processing field of the laser processing of the optical element wafer 10 by the alignment mechanism 8 and the control mechanism 7 is performed. That is, the alignment mechanism 8 and the control mechanism 7 perform the division planned line 13 for forming the predetermined direction of the optical element wafer 10, and the laser beam irradiation mechanism 6 for irradiating the laser beam along the division planned line 13. Light collecting mirror 65 The image matching of the alignment is performed such as image processing, and the alignment of the laser light irradiation position is completed. Further, the alignment of the laser beam irradiation position is similarly performed even in the division planned line 13 extending in the direction orthogonal to the predetermined direction of the optical element wafer 10.

In this manner, when the predetermined dividing line 13 formed on the optical element wafer 10 held on the chuck table 36 is detected and the laser beam irradiation position is aligned, as shown in FIG. 5, the chuck table 36 is moved to the laser. The field of the laser beam at the position where the collecting mirror 65 of the light illuminating mechanism 6 is located is positioned at one end of the predetermined dividing line 13 (left end in FIG. 5) directly below the collecting mirror 65. Further, the light collecting point P of the pulsed laser light irradiated by the collecting mirror 65 is positioned at a position lower than, for example, 15 μm from the inner surface 11b (upper surface) of the sapphire substrate 11 constituting the optical element wafer 10.

Next, the control unit 7 irradiates the pulsed laser light onto the sapphire substrate 11 constituting the optical element wafer 10 in accordance with the above-described determination condition, and at this time, it is judged whether the sapphire substrate 11 constituting the optical element wafer 10 is A by the occurrence of the reaction light. The sapphire substrate produced in batches is also a sapphire substrate (sapphire substrate judging step) manufactured in batches of B. That is, the laser beam irradiation mechanism 6 is operated to irradiate the sapphire substrate 11 with a wavelength of 532 nm, a repetition frequency of 45 kHz, and an average output of 0.03 W. The laser beam is irradiated onto the sapphire substrate 11 through the collecting mirror 65, and the arrow is shown in FIG. The direction indicated by X1 moves the chuck table 36 at a machining feed speed of 360 mm/sec. In the sapphire substrate determining step, as shown in FIG. 2, pulsed laser light having a wavelength of 532 nm which is irradiated onto the workpiece W (in the sapphire substrate determining step) is 532 nm, and constitutes an optical element crystal. The inner surface 11b (upper surface) of the sapphire substrate 11 of the circle 10 is reflected and passed through the collecting mirror 65. The beam splitter 66 is reflected by the beam splitter 66 and reaches the cut filter 67. Since the cut filter 67 blocks light having a wavelength of 510 to 550 nm as described above, the reflected light of the pulsed laser beam having a wavelength of 532 nm is blocked. On the other hand, when the sapphire substrate 11 constituting the optical element wafer 10 is reacted by irradiation of pulsed laser light, it is judged that blue (400 nm domain) reaction light is generated. Since the reaction light in the 400 nm field passes through the condensing mirror 65 to the beam splitter 66, and is reflected by the beam splitter 66 and passes through the cut filter 67, it is captured by the image pickup unit 68. As described above, when the pulsed laser beam having an average output of 0.03 W is irradiated onto the sapphire substrate 11 through the collecting mirror 65, the reaction light is generated, and when the reaction light is captured by the image capturing mechanism 68 by the cutting filter 67, the control mechanism 7 The sapphire substrate 11 constituting the optical element wafer 10 held by the chuck table 36 is determined to be a sapphire substrate manufactured in batches A. Further, when the pulsed laser beam having an average output of 0.03 W is irradiated onto the sapphire substrate 11 through the collecting mirror 65, the reflected light of the pulsed laser beam is cut off as described above when the reflected light does not occur. Since the filter 67 is blocked, the imaging unit 68 cannot capture light. Therefore, the control unit 7 determines that the sapphire substrate 10 constituting the optical element wafer 10 held by the chuck table 36 is a sapphire substrate manufactured in batches of B.

When the sapphire substrate determining step described above is carried out, the control unit 7 determines the processing conditions for the sapphire substrate 11 constituting the optical element wafer 10 held by the chuck table 36. In other words, when the sapphire substrate determining step in the sapphire substrate determining step determines that the sapphire substrate 11 constituting the optical element wafer 10 held by the chuck table 36 is a sapphire substrate manufactured in batch A, the control unit 7 determines the first processing condition. In the sapphire substrate determining step, it is determined that the composition is held in the chuck When the sapphire substrate 11 of the optical element wafer 10 of the stage 36 is a sapphire substrate manufactured in batch B, the second processing condition (processing condition determining step) is determined.

As described above, when the processing conditions of the sapphire substrate 11 constituting the optical element wafer 10 held by the chuck table 36 are determined, the sapphire substrate 11 constituting the optical element wafer 10 held by the chuck table 36 is determined. Processing conditions, the implementation of the reforming layer forming step.

To perform the reforming layer forming step, as shown in FIG. 6(a), the chuck table 36 is moved to the laser light irradiation field at the position of the collecting mirror 65, and a predetermined division formed on the optical element wafer 10 is performed. One end of the predetermined line 13 (left end in Fig. 6(a)) is positioned directly below the collecting mirror 65. Then, the light collecting point P of the pulsed laser beam irradiated by the collecting mirror 65 is positioned in the vicinity of the center in the thickness direction of the sapphire substrate 11 constituting the optical element wafer 10.

Next, the control unit 7 activates the laser beam illumination mechanism 6 to illuminate the pulsed laser beam from the concentrating mirror 65, and the operative feed mechanism 37 feeds in a predetermined direction in the direction indicated by the arrow X1 in Fig. 6(a). The speed causes the chuck table 36 to move (the reforming layer forming step). In the reforming layer forming step, when the sapphire substrate determining step determines that the sapphire substrate 11 constituting the optical element wafer 10 held by the chuck table 36 is a sapphire substrate manufactured in batch B, the second processing condition is determined. In the sapphire substrate determining step, it is determined that the sapphire substrate 11 constituting the optical element wafer 10 held by the chuck table 36 is a sapphire substrate manufactured in batch A, and is carried out under the above-described first processing conditions. Further, as shown in Fig. 6(b), when the irradiation position of the pulsed laser beam irradiated from the collecting mirror 65 reaches the other end of the dividing line 13 (the right end in Fig. 6(b)), the pulse is stopped. The illumination of the laser light is stopped and the movement of the chuck table 36 is stopped. the result, On the sapphire substrate 11 constituting the optical element wafer 10, as shown in Fig. 6(b), the modified layer 110 is formed along a predetermined planned dividing line 13. In this manner, since the reforming layer forming step is performed under the processing conditions set corresponding to the characteristics of the sapphire substrate constituting the optical element wafer 10 held by the chuck table 36, the so-called insufficient output of the pulsed laser light is solved. The reforming layer is insufficient, and the sapphire substrate is deviated from the dividing line by the excessive output of the pulsed laser light, and a crack is generated to damage the optical element.

As described above, when the reforming layer forming step is performed along all of the planned dividing lines 13 formed in the predetermined direction of the optical element wafer 10, the chuck table 36 holding the optical element wafer 10 is positioned after being rotated by 90 degrees. s position. Further, the reforming layer forming step is performed along all of the planned dividing lines 13 formed in the direction orthogonal to the predetermined direction of the optical element wafer 10.

As described above, in the reforming layer forming step, the optical element wafer 10 which has been carried out along all the dividing lines 13 is transported to the wafer dividing step which is broken along the dividing line 13 on which the modified layer is formed.

1‧‧‧ Laser processing equipment

2‧‧‧Static machine

3‧‧‧chate table mechanism

4‧‧‧Laser light irradiation unit support mechanism

5‧‧‧Laser light irradiation unit

6‧‧‧Laser light illumination mechanism

7‧‧‧Control agency

8‧‧‧Alignment mechanism

9‧‧‧Monitor

10‧‧‧Light component wafer

10a‧‧‧ surface

11‧‧‧Sapphire substrate 11

11a‧‧‧ surface

11b‧‧‧ inside

12‧‧‧Light component layer

13‧‧‧Division line

14‧‧‧Light components

31‧‧‧ Guided track

32‧‧‧1st sliding block

33‧‧‧2nd sliding block

34‧‧‧Cylinder components

35‧‧‧ Cover

36‧‧‧ chuck table

37‧‧‧Processing feed mechanism

38‧‧‧1st calculation transfer mechanism

41‧‧‧Guided track

42‧‧‧ movable support abutment

43‧‧‧2nd calculation transfer mechanism

51‧‧‧Unit Supporter

53‧‧‧Light spot adjustment mechanism

61‧‧‧Shell

62‧‧‧Pulse laser oscillating mechanism

63‧‧‧Output adjustment mechanism

64‧‧‧ Directional change mirror

65‧‧‧Photoscope

66‧‧‧beam splitter

67‧‧‧ cut filter

68‧‧‧ camera organization

70‧‧‧ Input institutions

71‧‧‧ memory

110‧‧‧Modified layer

121‧‧‧n type nitride semiconductor layer

122‧‧‧p-type nitride semiconductor layer

321‧‧‧Guided ditch

322‧‧‧Guided track

331‧‧‧Guided ditch

361‧‧‧Adsorption chuck

362‧‧‧ fixture

371‧‧‧Male screw

372‧‧‧pulse motor

381‧‧‧Male screw

382‧‧‧pulse motor

373‧‧‧ bearing block

383‧‧‧ bearing block

421‧‧‧Mobile Support Department

422‧‧‧Installation Department

423‧‧‧ Guided track

431‧‧‧Male screw

432‧‧‧pulse motor

511‧‧‧guided ditch

532‧‧‧pulse motor

621‧‧‧pulse laser ray oscillator

622‧‧‧Repeat frequency setting mechanism

F‧‧‧Ring frame

P‧‧‧Light spot

T‧‧‧Adhesive tape

W‧‧‧Processed objects

X1‧‧‧ arrow

Fig. 1 is a perspective view of a laser processing apparatus for carrying out a method of processing a sapphire substrate of the present invention.

Fig. 2 is a block diagram schematically showing the configuration of a laser beam irradiation mechanism equipped in the laser processing apparatus shown in Fig. 1.

3(a) to 3(b) are perspective views of the optical element wafer processed by the processing method of the sapphire substrate of the present invention.

Fig. 4 is a perspective view showing a state in which the optical element wafer shown in Fig. 3 is attached to a protective tape attached to the annular frame.

Fig. 5 is an explanatory view showing a setting condition of a discrimination condition of a processing method of the sapphire substrate of the present invention.

6(a) to 6(b) are explanatory views of the reforming layer forming step of the processing method of the sapphire substrate of the present invention.

6‧‧‧Laser light illumination mechanism

7‧‧‧Control agency

8‧‧‧Alignment mechanism

9‧‧‧Monitor

36‧‧‧ chuck table

62‧‧‧Pulse laser oscillating mechanism

63‧‧‧Output adjustment mechanism

64‧‧‧ Directional change mirror

65‧‧‧Photoscope

66‧‧‧beam splitter

67‧‧‧ cut filter

68‧‧‧ camera organization

70‧‧‧ Input institutions

71‧‧‧ memory

621‧‧‧pulse laser ray oscillator

622‧‧‧Repeat frequency setting mechanism

W‧‧‧Processed objects

Claims (2)

A laser processing method is characterized in that a pulverized laser beam having a wavelength of transparency is internally irradiated to a sapphire substrate and irradiated along a dividing line, and is formed as a breaking starting point along a dividing line in the interior of the sapphire substrate. The processing method for the sapphire substrate of the modified layer is characterized in that the laser processing method includes: a processing condition setting step of setting at least two types of processing conditions corresponding to characteristics of the sapphire substrate; and a determination condition setting step for determining a sapphire substrate having at least two types of processing conditions set; a processing condition determining step of determining a sapphire substrate based on the determination condition set by the determination condition setting step, and the processing condition setting step from the determined sapphire substrate At least two types of processing conditions are set to determine one processing condition; and the reforming layer forming step is to position the spot of the laser light to the inside of the sapphire substrate according to the processing conditions determined in the processing condition determining step. , illuminating along the dividing line, dividing along the inside of the sapphire substrate Forming alignment becomes a starting point of breakage modified layer. The laser processing method of claim 1, wherein the determining condition setting step irradiates the laser light to the inside of the sapphire substrate, and the output of the laser light is not processed to the sapphire substrate, according to the The reaction light of the light is emitted, and the laser light outputting the boundary of the reaction light is outputted, and the judgment condition is set.