JP2016174092A - Method for manufacturing optical device chip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical device chip capable of preventing damage to an optical device wafer.SOLUTION: A method for manufacturing an optical device chip includes: a fixing step of fixing a surface (11a) side of an optical device wafer (11) to a support substrate (1) with an adhesive (3); a grinding step of grinding a rear surface (11b) side of the optical device wafer; a polishing step of polishing the rear surface side of the optical device wafer; a reflection film forming step of forming a reflection film (17) on the rear surface side of the optical device wafer; a laser processing step of forming a fracture starting point(19) along lines to be divided (13) of the optical device wafer; a sticking step of sticking an expand tape (21) to the rear surface side of the optical device wafer; a peeling step of dissolving the adhesive by infiltrating a chemical (25) into the support substrate, and peeling the support substrate from the optical device wafer; and a dividing step of dividing the optical device wafer into a plurality of optical device chips (29).SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical device chip manufacturing method applied when manufacturing a light-emitting optical device chip.

  When manufacturing an optical device chip such as a light emitting diode (LED) or a laser diode (LD), an optical device including a light emitting layer is formed on the surface of a crystal growth substrate made of sapphire, SiC, or the like by a method such as epitaxial growth. It is formed. A substrate (optical device wafer) on which an optical device is formed is divided into a plurality of optical device chips along a planned division line (street).

  In recent years, a technique for forming a reflection film called a DBR (Distributed Bragg Reflector) film using Bragg reflection on the back surface of an optical device wafer has been proposed (see, for example, Patent Document 1 and Patent Document 2). By forming this reflective film, light emitted from the light emitting layer to the back side of the optical device can be reflected to increase the light extraction efficiency on the front side.

JP 2013-235877 A JP 2014-82364 A

  The reflective film described above is formed, for example, under a temperature condition of 150 ° C. or higher in the chamber of the film forming apparatus. However, if the reflection film is formed after the optical device wafer is thinned by a method such as grinding, there is a high possibility that the optical device wafer will be damaged when it is put into the chamber or taken out from the chamber.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an optical device chip manufacturing method that prevents damage to the optical device wafer.

  According to the present invention, an optical device chip for manufacturing a plurality of optical device chips by dividing an optical device wafer in which an optical device is formed in a region divided by divided dividing lines intersecting with each other along the divided dividing lines. The surface side of the optical device wafer is bonded to the plate-like support substrate made of a porous material or the plate-like support substrate having a plurality of pores extending from one surface to the other surface. A fixing step for fixing the optical device wafer, a grinding step for thinning the optical device wafer by grinding the back surface side of the optical device wafer, and a back surface of the optical device wafer after performing the grinding step. A polishing step for polishing the side, and after performing the polishing step, an optical device wafer fixed to the support substrate is put into a chamber of the film forming apparatus, and the optical device wafer is A reflective film forming step for forming a reflective film on the back side of the substrate, and a laser beam from the back side along the planned dividing line of the optical device wafer taken out from the chamber after performing the reflective film forming step. Irradiating and forming a break starting point on the optical device wafer; after performing the laser processing step, performing an adhesion step of adhering an expanded tape to the back side of the optical device wafer; and performing the adhesion step Then, a chemical solution is infiltrated into the support substrate to dissolve the adhesive, and after performing the peeling step for peeling the support substrate from the optical device wafer, an external force is applied to the optical device wafer. Dividing the optical device wafer into a plurality of optical device chips, and manufacturing the optical device chip The law is provided.

  In the present invention, in the laser processing step, it is preferable to use the laser beam having a wavelength that is transmissive to the optical device wafer, and to form a modified layer serving as the fracture starting point inside the optical device wafer.

  In the method of manufacturing an optical device chip according to the present invention, with the front surface side of the optical device wafer fixed to the support substrate, grinding and polishing on the back surface side of the optical device wafer, film formation of the reflective film, and formation of the break start point. Since a series of steps are performed, the optical device wafer is reinforced with the support substrate during the series of steps. As a result, the optical device wafer can be prevented from being damaged when it is put into the chamber or taken out from the chamber.

  Furthermore, in the method for manufacturing an optical device chip according to the present invention, a plate-shaped support substrate made of a porous material or a plate-shaped support substrate having a plurality of pores extending from one surface to the other surface is used. When the expandable tape is attached to the device wafer, the chemical solution is infiltrated into the support substrate to dissolve the adhesive between the support substrate and the optical device wafer, so when using a heat-resistant adhesive that is difficult to soften by heat However, the supporting substrate can be easily peeled from the optical device wafer without applying a large external force. This can prevent the optical device wafer from being damaged when the support substrate is peeled off.

It is a perspective view which shows typically a mode that an adhesive agent is apply | coated to a support substrate in a fixing step. 2A and 2B are perspective views schematically showing how the optical device wafer is fixed to the support substrate in the fixing step. It is a partial cross section side view which shows a grinding step typically. It is a partial cross section side view which shows a grinding | polishing step typically. It is a partial cross section side view showing typically a reflective film formation step. It is a partial cross section side view showing typically a laser processing step. It is a partial cross section side view which shows a sticking step typically. It is sectional drawing which shows a peeling step typically. It is a partial cross section side view showing a division step typically.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The optical device chip manufacturing method according to the present embodiment includes a fixing step (see FIGS. 1, 2A and 2B), a grinding step (see FIG. 3), a polishing step (see FIG. 4), and a reflection. A film forming step (see FIG. 5), a laser processing step (see FIG. 6), a sticking step (see FIG. 7), a peeling step (see FIG. 8), and a dividing step (see FIG. 9) are included.

  In the fixing step, the surface side of the optical device wafer is fixed to the plate-like support substrate using an adhesive. In the grinding step, the back side of the optical device wafer is ground. In the polishing step, the back side of the optical device wafer is polished.

  In the reflective film deposition step, the optical device wafer is put into a chamber of the film deposition apparatus to deposit a reflective film on the back side of the optical device wafer. In the laser processing step, a laser beam is irradiated from the back side along the planned division line (street) of the optical device wafer to form a modified layer serving as a starting point (breaking start point) of the optical device wafer.

  In the attaching step, an expanded tape is attached to the back side of the optical device wafer. In the peeling step, the chemical solution is permeated into the support substrate to dissolve the adhesive, and the support substrate is peeled from the optical device wafer. In the dividing step, the optical device wafer is divided into a plurality of optical device chips by applying an external force to the optical device wafer. Hereinafter, the manufacturing method of the optical device chip according to the present embodiment will be described in detail.

  First, a fixing step of fixing the surface side of the optical device wafer to the plate-like support substrate is performed. FIG. 1 is a perspective view schematically showing a state in which an adhesive is applied to a support substrate in a fixing step, and FIGS. 2A and 2B fix an optical device wafer to the support substrate in the fixing step. It is a perspective view which shows a mode to do typically.

  As shown in FIGS. 2A and 2B, the optical device wafer 11 according to the present embodiment is a circular plate-like object made of sapphire, SiC, etc., and the surface 11a side intersects with each other. A plurality of division lines (streets) 13 are divided into a plurality of areas. In each region, an optical device 15 serving as a light emitting diode (LED) or a laser diode (LD) is formed. Each optical device 15 includes a light emitting layer formed by a method such as epitaxial growth.

  On the other hand, as shown in FIG. 1, FIG. 2 (A) and FIG. 2 (B), the support substrate 1 according to the present embodiment is, for example, a circular plate-like object formed of a porous material, It has a plurality of pores. As the support substrate 1, a dress board for dressing a grinding wheel (grinding wheel) or the like can be used.

  However, the support substrate 1 may be formed of a material other than the porous material. For example, if it is a plate-like object having a plurality of pores extending from the first surface (one surface) 1a to the second surface (the other surface) 1b and capable of appropriately performing the peeling step described later, Regardless, it can be used as the support substrate 1. Note that the diameter of the support substrate 1 is preferably equal to or larger than the diameter of the optical device wafer 11.

  In the fixing step, first, an adhesive is applied to the first surface 1a of the support substrate 1 described above. The application of the adhesive is performed by, for example, the spin coater 2 shown in FIG. The spin coater 2 includes a spinner table 4 that holds the support substrate 1. The spinner table 4 is connected to a rotation drive source (not shown) such as a motor, and rotates around a rotation axis parallel to the vertical direction.

  The upper surface of the spinner table 4 is a holding surface that holds the second surface 1 b side of the support substrate 1. A negative pressure of a suction source (not shown) acts on the holding surface through a flow path (not shown) formed inside the spinner table 4 to generate a suction force for sucking the support substrate 1. Above the spinner table 4, a nozzle 6 for ejecting the adhesive 3 made of a liquid resin or the like is disposed. The nozzle 6 swings in the radial direction of the spinner table 4.

  When applying the adhesive 3, first, the support substrate 1 is placed on the spinner table 4 so that the first surface 1 a side is exposed upward, and a negative pressure of a suction source is applied to the holding surface. Next, the nozzle 6 is swung while rotating the spinner table 4, and the adhesive 3 is dropped on the first surface 1 a of the support substrate 1. As a result, the adhesive 3 is applied to the first surface 1 a of the support substrate 1.

  Note that the adhesive 3 used in the present embodiment has heat resistance enough to maintain a sufficient adhesive force in the subsequent reflective film forming step. The adhesive 3 is adjusted to a viscosity that can be applied by a spin coating method and does not ooze from the second surface 1b side through the pores of the support substrate 1.

  After the adhesive 3 is applied to the first surface 1a of the support substrate 1, the surface 11a of the optical device wafer 11 and the first surface 1a of the support substrate 1 face each other as shown in FIG. The optical device wafer 11 is brought into close contact with the substrate 1. As a result, as shown in FIG. 2B, the surface 11 a side of the optical device wafer 11 is fixed to the first surface 1 a side of the support substrate 1 by the adhesive force of the adhesive 3.

  After performing the fixing step, a grinding step for grinding the back surface 11b side of the optical device wafer 11 is performed. FIG. 3 is a partial cross-sectional side view schematically showing the grinding step. The grinding step is performed by, for example, the grinding device 12 shown in FIG. The grinding apparatus 12 includes a chuck table 14 that holds the support substrate 1 on which the optical device wafer 11 is fixed.

  The chuck table 14 is connected to a rotation drive source (not shown) such as a motor, and rotates around a rotation axis parallel to the vertical direction. Further, a moving unit (not shown) is provided below the chuck table 14, and the chuck table 14 is moved in the horizontal direction by the moving unit.

  The upper surface of the chuck table 14 is a holding surface that holds the second surface 1 b side of the support substrate 1. A negative pressure of a suction source (not shown) acts on the holding surface through a flow path (not shown) formed inside the chuck table 14 to generate a suction force for sucking the support substrate 1.

  A grinding unit 16 for grinding the optical device wafer 11 is disposed above the chuck table 14. The grinding unit 16 includes a spindle housing 18 that is moved up and down by a lifting unit (not shown). The spindle housing 18 accommodates a spindle 20 that constitutes a rotation axis parallel to the vertical direction.

  A disc-shaped wheel mount 22 is fixed to the lower end portion of the spindle 20. A grinding wheel 24 having substantially the same diameter as the wheel mount 22 is mounted on the lower surface of the wheel mount 22. The grinding wheel 24 includes a wheel base 26 made of a metal material such as stainless steel or aluminum. A plurality of grinding wheels 28 are fixed to the lower surface of the wheel base 26 in an annular shape.

  A rotation drive source (not shown) such as a motor is connected to the upper end side (base end side) of the spindle 20. The grinding wheel 24 rotates around a rotation axis parallel to the vertical direction by the rotational force transmitted from the rotational drive source.

  In the grinding step, first, the second surface 1b side of the support substrate 1 is held on the chuck table 14 so that the back surface 11b side of the optical device wafer 11 is exposed upward. Next, the grinding wheel 24 is lowered while the chuck table 14 and the spindle 20 are rotated relative to each other, and the lower portion of the grinding wheel 28 is brought into contact with the back surface 11b of the optical device wafer 11 while supplying a grinding liquid such as pure water. Thereby, the optical device wafer 11 can be thinned by grinding the back surface 11b side.

  After performing the grinding step, a polishing step for polishing the back surface 11b side of the optical device wafer 11 is performed. FIG. 4 is a partial cross-sectional side view schematically showing the polishing step. The polishing step is performed by, for example, the polishing apparatus 32 shown in FIG. The polishing apparatus 32 includes a chuck table 34 that holds the support substrate 1 on which the optical device wafer 11 is fixed.

  The chuck table 34 is connected to a rotation drive source (not shown) such as a motor, and rotates around a rotation axis parallel to the vertical direction. A moving unit (not shown) is provided below the chuck table 34, and the chuck table 34 is moved in the horizontal direction by the moving unit.

  The upper surface of the chuck table 34 is a holding surface that holds the second surface 1 b side of the support substrate 1. A negative pressure of a suction source (not shown) acts on the holding surface through a channel (not shown) formed inside the chuck table 34, and a suction force for sucking the support substrate 1 is generated.

  A polishing unit 36 for polishing the optical device wafer 11 is disposed above the chuck table 34. The polishing unit 36 includes a spindle housing 38 that is moved up and down by a lifting unit (not shown). The spindle housing 38 accommodates a spindle 40 that constitutes a rotation axis parallel to the vertical direction.

  A disc-shaped mount 42 is fixed to the lower end portion of the spindle 40. A polishing pad 44 having substantially the same diameter as the mount 42 is attached to the lower surface of the mount 42. A rotation drive source (not shown) such as a motor is connected to the upper end side (base end side) of the spindle 40. The polishing pad 44 rotates around a rotation axis parallel to the vertical direction by the rotational force transmitted from the rotational drive source.

  In the polishing step, first, the second surface 1b side of the support substrate 1 is held on the chuck table 34 so that the back surface 11b side of the optical device wafer 11 is exposed upward. Next, the polishing pad 44 is lowered while the chuck table 34 and the spindle 40 are rotated relative to each other, and the lower surface of the polishing pad 44 is brought into contact with the back surface 11b of the optical device wafer 11 while supplying a polishing liquid such as slurry. Thereby, the back surface 11b side of the optical device wafer 11 can be polished.

  After performing the polishing step, a reflective film deposition step is performed in which a reflective film is deposited on the back surface 11 b side of the optical device wafer 11. FIG. 5 is a partial cross-sectional side view schematically showing the reflective film forming step. The reflective film deposition step is performed by, for example, the film deposition apparatus 52 shown in FIG.

  The film forming apparatus 52 is configured so that a reflective film can be formed by a method such as vacuum deposition, CVD, or sputtering, and includes a chamber 54 having a film forming chamber therein. A table 56 for placing the support substrate 1 on which the optical device wafer 11 is fixed is disposed in the film forming chamber of the chamber 54.

  In a part of the side wall of the chamber 54, an opening 54a for carrying in and out the support substrate 1 on which the optical device wafer 11 is fixed is formed. A gate 58 that closes the opening 54a is provided outside the opening 54a.

  In the reflective film formation step, first, the support substrate 1 to which the optical device wafer 11 is fixed is put into the chamber 54, and the support substrate 1 is placed on the table 56 so that the back surface 11b side is exposed upward.

  Next, the opening 54 a is closed by the gate 58, and the reflective film 17 is formed on the back surface 11 b side of the optical device wafer 11. In the present embodiment, a DBR (Distributed Bragg Reflector) film or the like in which two or more kinds of dielectric films having different refractive indexes are periodically laminated so that light emitted from the optical device 15 can be selectively reflected is used. A so-called reflective film 17 is formed.

  The reflective film 17 is generally formed under a temperature condition of 150 ° C. or higher. In this embodiment, since the heat-resistant adhesive 3 is used, the support substrate 1 does not peel from the optical device wafer 11 even under such temperature conditions. After the reflective film 17 is formed, the support substrate 1 to which the optical device wafer 11 is fixed is taken out from the chamber 54.

  After performing the reflective film forming step, a laser beam is irradiated from the back surface 11b side along the scheduled division line 13 of the optical device wafer 11, and a modified layer serving as a starting point of breaking (breaking start point) is applied to the optical device wafer 11. The laser processing step to be formed is performed. FIG. 6 is a partial cross-sectional side view schematically showing the laser processing step. The laser processing step is performed by, for example, a laser processing apparatus 62 shown in FIG.

  The laser processing apparatus 62 includes a chuck table 64 that holds the support substrate 1 on which the optical device wafer 11 is fixed. The chuck table 64 is connected to a rotation drive source (not shown) such as a motor, and rotates around a rotation axis parallel to the vertical direction. A moving unit (not shown) is provided below the chuck table 64, and the chuck table 64 is moved in the horizontal direction by the moving unit.

  The upper surface of the chuck table 64 is a holding surface that holds the second surface 1 b side of the support substrate 1. A negative pressure of a suction source (not shown) acts on the holding surface through a flow path (not shown) formed inside the chuck table 64, and a suction force for sucking the support substrate 1 is generated. A laser processing unit 66 is disposed above the chuck table 64.

  The laser processing unit 66 condenses the laser beam L pulse-oscillated by a laser oscillator (not shown) inside the optical device wafer 11 on the chuck table 64. The laser oscillator is configured to be able to oscillate a laser beam L having a wavelength that is difficult to be absorbed by the optical device wafer 11 (wavelength having transparency).

  In the laser processing step, first, the second surface 1b side of the support substrate 1 is held on the chuck table 64 so that the back surface 11b side of the optical device wafer 11 is positioned upward. Next, the chuck table 64 is moved and rotated to align the laser processing unit 66 with the division line 13 to be processed.

  Thereafter, while irradiating the laser beam L from the laser processing unit 66 toward the optical device wafer 11, the chuck table 64 is moved in a direction parallel to the division line 13 to be processed. Thereby, multiphoton absorption is generated in the vicinity of the condensing point of the laser beam L, and a linear modified layer (breaking start point) 19 along the planned dividing line 13 can be formed.

  Since the reflection film 17 is configured to selectively reflect only light having a predetermined wavelength emitted from the optical device 15, the laser beam L emitted from the laser processing unit 66 passes through the reflection film 17. The light is transmitted and condensed inside the optical device wafer 11. When the above-described operation is repeated and the modified layer 19 is formed along all the division lines 13, the laser processing step ends.

  After performing the laser processing step, an attaching step of attaching an expand tape to the back surface 11b side of the optical device wafer 11 is performed. FIG. 7 is a partial cross-sectional side view schematically showing the attaching step.

  In the attaching step, as shown in FIG. 7, the support substrate 1 is placed on the table 72 so that the back surface 11 b side of the optical device wafer 11 is positioned upward, and the expanded tape 21 having a larger diameter than the optical device wafer 11 is placed on the back surface. Adhere to 11b. An annular frame 23 is fixed to the outer peripheral portion of the expanding tape 21.

  After carrying out the sticking step, a peeling step for peeling the support substrate 1 from the optical device wafer 11 is performed by allowing the chemical solution to penetrate into the support substrate 1 to dissolve the adhesive 3. FIG. 8 is a cross-sectional view schematically showing the peeling step.

  In the peeling step, as shown in FIG. 8, the chemical bath 74 is filled with a chemical solution 25 such as alcohol that can dissolve the adhesive 3, and the support substrate 1 and the optical device wafer 11 are immersed in the chemical solution 25. Since the support substrate 1 has a plurality of pores, when the support substrate 1 and the optical device wafer 11 are immersed in the chemical solution 25, the chemical solution 25 acts on the adhesive 3 through the pores and dissolves the adhesive 3. . Thereby, the support substrate 1 can be peeled from the optical device wafer 11.

  In this embodiment, since the chemical | medical solution 25 osmose | permeates the support substrate 1, the adhesive agent 3 which is hard to soften with heat can be melt | dissolved and removed easily. Moreover, since the expand tape 21 is stuck on the optical device wafer 11, the local external force applied to the optical device wafer 11 when peeling off the support substrate 1 can be suppressed. Thereby, when peeling off the support substrate 1, damage at positions other than the modified layer 19 of the optical device wafer 11 can be prevented.

  After performing the peeling step, the dividing step of applying an external force to the optical device wafer 11 to divide the optical device wafer 11 into a plurality of optical device chips is performed. FIG. 9 is a partial cross-sectional side view schematically showing the dividing step.

  The dividing step is performed, for example, by a braking device 82 shown in FIG. The braking device 82 includes a pair of support plates 84 and 86 that support the optical device wafer 11, a pressing blade 88 disposed above the support plates 84 and 86, and the optical device wafer 11 below the support plates 84 and 86. And a camera 90 for capturing the image. The pressing blade 88 is positioned between the support plate 84 and the support plate 86, and is moved (lifted / lowered) in the vertical direction by a pressing mechanism (not shown).

  In the dividing step, first, the optical device wafer 11 is placed on the support plates 84 and 86 so that the surface 11a side is positioned downward, and the camera 90 images the surface 11a side of the optical device wafer 11. A protective member 27 is installed in advance between the surface 11 a side of the optical device wafer 11 and the support plates 84 and 86. The protection member 27 is formed of a material such as a transparent resin, for example, and the division line 13 of the optical device wafer 11 can be imaged by the camera 90 through the protection member 27.

  After imaging the surface 11 a side of the optical device wafer 11 with the camera 90, the optical device wafer 11 and the support plates 84 and 86 are moved relative to each other based on the captured image, and the modified layer 19 is moved to the support plate 84. Position between the support plate 86. That is, as shown in FIG. 9, the modified layer 19 is moved directly below the pressing blade 88.

  Thereafter, the pressing blade 88 is lowered, and the optical device wafer 11 is pressed by the pressing blade 88 from the back surface 11b side. The optical device wafer 11 is supported on both sides of the modified layer 19 from below by support plates 84 and 86. For this reason, when the optical device wafer 11 is pressed by the pressing blade 88, a downward bending stress is applied in the vicinity of the modified layer 19, and the optical device wafer 11 is divided along the division line 13. When the optical device wafer 11 is divided along all the planned dividing lines 13 and a plurality of optical device chips 29 corresponding to the respective optical devices 15 are formed, the dividing step is completed.

  As described above, in the method for manufacturing an optical device chip according to the present embodiment, grinding, polishing, and reflection on the back surface 11b side of the optical device wafer 11 with the front surface 11a side of the optical device wafer 11 fixed to the support substrate 1. Since a series of steps of forming the film 17 and forming a modified layer (breaking origin) 19 is performed, the optical device wafer 11 is reinforced by the support substrate 1 during this series of steps. When a single optical device wafer 11 that is not reinforced by the support substrate 1 is ground and polished, the optical device wafer 11 is easily warped and easily damaged, but in this embodiment, the optical device wafer 11 is always attached to the support substrate 1. Since it is supported, it is possible to prevent the optical device wafer 11 from being damaged when being inserted into the chamber 54 or taken out from the chamber 54.

  Furthermore, in the method for manufacturing an optical device chip according to the present embodiment, the plate-like support substrate 1 (or the first surface (one surface) 1a) made of a porous material extends from the second surface (the other surface) 1b. A plate-like support substrate 1) having a plurality of pores is used, and a chemical solution 25 is infiltrated into the support substrate 1 with the expanded tape 21 attached to the optical device wafer 11 so that the support substrate 1 and the optical device wafer 11 are bonded. Since the adhesive 3 in between is dissolved, the support substrate 1 can be easily peeled from the optical device wafer 11 without applying a large external force even when the heat-resistant adhesive 3 that is not easily softened by heat is used. Thereby, when the support substrate 1 is peeled, the optical device wafer 11 can be prevented from being damaged.

  In addition, this invention is not limited to description of the said embodiment, A various change can be implemented. For example, in the above embodiment, the adhesive 3 is applied to the support substrate 1 side in the fixing step, but the adhesive may be applied to the optical device wafer side.

  On the other hand, when the adhesive 3 is applied to the entire first surface 1a of the support substrate 1 as in the above-described embodiment, the reflective film 17 is formed on the outer peripheral portion of the support substrate 1 exposed in a state where the optical device wafer 11 is fixed. However, the reflective film 17 can be easily removed by dissolving the adhesive 3 with the chemical solution 25. Therefore, in this case, the support substrate 1 can be easily reused.

  In the above embodiment, a polishing liquid such as a slurry is used in the polishing step. However, the optical device wafer may be polished without using the polishing liquid. In dry polishing without using a polishing liquid, an optical device wafer or the like is likely to become high temperature, and when a general thermoplastic adhesive is used, the support substrate is peeled off from the optical device wafer.

  In contrast, in the present invention, a support substrate having a porous structure is used, and a peeling step is used in which a chemical solution is permeated into the support substrate to dissolve the adhesive, so that a heat-resistant adhesive can be used. Even when dry polishing is employed, peeling of the support substrate can be prevented.

  In the above embodiment, the modified layer 19 by multiphoton absorption is formed in the laser processing step. However, a groove or the like by ablation may be formed as a starting point of fracture (breaking origin). In addition, the configurations, methods, and the like according to the above-described embodiments can be appropriately modified and implemented without departing from the scope of the object of the present invention.

1 Support substrate 1a First surface (one surface)
1b Second surface (the other surface)
3 Adhesive 11 Optical Device Wafer 11a Front 11b Back 13 Scheduled Line (Street)
15 Optical device 17 Reflective film 19 Modified layer (breaking origin)
DESCRIPTION OF SYMBOLS 21 Expand tape 23 Frame 25 Chemical solution 27 Protection member 29 Optical device chip L Laser beam 2 Spin coater 4 Spinner table 6 Nozzle 12 Grinding device 14 Chuck table 16 Grinding unit 18 Spindle housing 20 Spindle 22 Wheel mount 24 Grinding wheel 26 Wheel base 28 Grinding Grinding wheel 32 Polishing device 34 Chuck table 36 Polishing unit 38 Spindle housing 40 Spindle 42 Mount 44 Polishing pad 52 Film forming device 54 Chamber 54a Opening 56 Table 58 Gate 62 Laser processing device 64 Chuck table 66 Laser processing unit 72 Table 74 Chemical solution tank 82 Brake Device 84, 86 Support plate 88 Press blade 90 Camera

Claims (2)

An optical device chip manufacturing method for manufacturing a plurality of optical device chips by dividing an optical device wafer in which an optical device is formed in a region divided by divided division lines intersecting the surface along the division division lines. ,
A fixing step of fixing the surface side of the optical device wafer with an adhesive to a plate-like support substrate made of a porous material, or a plate-like support substrate having a plurality of pores extending from one surface to the other surface;
After carrying out the fixing step, grinding the back side of the optical device wafer to thin the optical device wafer; and
A polishing step of polishing the back side of the optical device wafer after performing the grinding step;
After performing the polishing step, the optical device wafer fixed to the support substrate is put into a chamber of the film forming apparatus, and a reflective film forming step of forming a reflective film on the back side of the optical device wafer;
After performing the reflective film forming step, a laser processing step of irradiating a laser beam from the back side along the planned division line of the optical device wafer taken out from the chamber, and forming a fracture starting point on the optical device wafer;
After performing the laser processing step, an attaching step of attaching an expand tape to the back side of the optical device wafer;
After performing the adhering step, a chemical solution is infiltrated into the support substrate to dissolve the adhesive, and a peeling step for peeling the support substrate from the optical device wafer;
And a splitting step of splitting the optical device wafer into a plurality of optical device chips by applying an external force to the optical device wafer after performing the peeling step.   2. The light according to claim 1, wherein in the laser processing step, the modified layer serving as the rupture starting point is formed inside the optical device wafer by using the laser beam having a wavelength that is transparent to the optical device wafer. Device chip manufacturing method.

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