KR20110058667A - Manufacturing method of optical device - Google Patents

Abstract

PURPOSE: A manufacturing method of an optical device is provided to form an optical device layer to perform a deformed layer forming process before an optical device is generated, thereby preventing damage of the optical device layer due to a laser ray. CONSTITUTION: A deformed layer is formed on the rear side(20b) of a substrate(20). The deformed layer is separated from the surface(20a) of the substrate. An optical device layer is laminated on the surface of the substrate. A protection member is fused on the surface of an optical device wafer(2). The rear side of the optical device wafer is grinded by a rear side grinding process. The optical device wafer is fractured along with a street formed in the deformed layer and is divided into individual optical devices.

Description

Manufacturing method of optical device {MANUFACTURING METHOD OF OPTICAL DEVICE}

TECHNICAL FIELD This invention relates to the manufacturing method of optical devices, such as a light emitting diode and a laser diode.

In the optical device manufacturing process, an optical device layer made of a gallium nitride compound semiconductor is laminated on a surface of a substantially sapphire substrate or a silicon carbide substrate, and a light emitting diode is formed in a plurality of regions partitioned by a plurality of streets formed in a lattice shape. An optical device such as a laser diode is formed to form an optical device wafer. And the optical device wafer is cut | disconnected along the street, and the area | region in which the optical device was formed is divided | segmented, and individual optical devices are manufactured.

Cutting along the street of the optical device wafer mentioned above is normally performed by the cutting apparatus called a dicer. This cutting device is provided with the chuck table which hold | maintains a to-be-processed object, the cutting means for cutting the workpiece hold | maintained by the said chuck table, and the cutting feed means which makes the chuck table and cutting means move relatively. The cutting means includes a rotating spindle, a cutting blade mounted to the spindle, and a drive mechanism for rotationally driving the rotating spindle. The cutting blade includes a disk-shaped base and an annular cutting blade mounted on the side outer periphery of the base, and the cutting blade is formed to have a thickness of about 20 μm by fixing diamond abrasive grains having a particle diameter of about 3 μm to the base by electroforming, for example. have.

By the way, since the sapphire substrate, silicon carbide substrate, etc. which comprise an optical device wafer have a high Mohs hardness, the cutting by the said cutting blade is not necessarily easy. In addition, since the cutting blade has a thickness of about 20 μm, a width of about 50 μm is required as the street for partitioning the device. For this reason, the area ratio which a street occupies becomes high and there exists a problem that productivity is bad.

In order to solve the above-mentioned problem, as a method of dividing an optical device wafer along a street, a laser processing groove serving as a starting point of fracture is formed by irradiating a pulsed laser beam having absorptivity with respect to the wafer along the street, A method of dividing by applying an external force along a street on which a laser processing groove as a starting point is formed is proposed (see Patent Document 1, for example).

By the way, when a laser beam is formed by irradiating a laser beam along the street formed on the surface of the sapphire substrate which comprises an optical device wafer, the outer periphery of optical devices, such as a light emitting diode, will abrasion and brightness will fall, and an optical device There is a problem that the quality of is lowered.

In order to solve such a problem, the laser beam of the wavelength which has a permeability with respect to a sapphire substrate from the back surface side of the sapphire substrate in which the light emitting layer (epi layer) as an optical device layer is not formed is located inside a condensing point, and is located along the street. The following patent document 2 discloses a processing method of a sapphire substrate in which the sapphire substrate is divided along the street on which the deterioration layer is formed by irradiating and forming a deterioration layer along the street inside the sapphire substrate.

[Patent Document 1] Japanese Patent Application Laid-Open No. 10-305420 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-6492

In the method of dividing a wafer disclosed in the Patent Document 2, first, the back surface of the wafer is ground in order to make the wafer into a predetermined thickness (for example, 100 μm or less), and then pulsed pulsed laser beams having a wavelength transmissive to the wafer From the back side, the light-converging point is set inside and irradiated along the street to form a deterioration layer which becomes the starting point of fracture along the street inside the wafer, but when the deterioration layer reaches the light emitting layer (epilayer) as the optical device layer, the optical device layer This damages the brightness of the optical device. In order to solve this problem, it is necessary to form a deterioration layer in the range which does not reach an optical device layer. By the way, it is very difficult to form a deterioration layer in the range which does not reach an optical device layer in the thin state that the thickness of a wafer is 100 micrometers or less.

This invention is made | formed in view of the said fact, The main technical subject is providing the manufacturing method of the optical device which can obtain the optical device which has a predetermined thickness, without damaging an optical device layer.

In order to solve the main technical problem, according to the present invention, the optical device wafer is formed along the street, the optical device wafer is formed in a plurality of areas partitioned by a plurality of streets formed by lattice and the optical device layer is laminated on the surface of the substrate As a manufacturing method of an optical device divided into individual optical devices,

A laser beam having a wavelength transmissive with respect to the substrate is irradiated to a region corresponding to the street by placing a light collecting point in the interior of the substrate from the back surface side of the substrate, and deteriorating the back surface side at a predetermined distance from the surface of the substrate inside the substrate. A deterioration layer forming step of forming a layer,

An optical device wafer forming step of forming an optical device wafer by laminating an optical device layer on a surface of the substrate subjected to the deterioration layer forming step and forming the optical device in a plurality of regions partitioned by a plurality of streets formed in a lattice shape; ,

A protective member adhesion step of adhering the protective member to the surface of the optical device wafer,

A back surface grinding step of grinding the back surface of the substrate of the optical device wafer to form a predetermined thickness;

And a wafer breaking step of applying an external force to the optical device wafer subjected to the backside grinding step, breaking the optical device wafer along the street on which the altered layer is formed, and dividing the optical device wafer into individual optical devices. This is provided.

The predetermined space | interval from the surface of the board | substrate in the said deterioration layer formation process is set to 5-60 micrometers.

The said protective member adhesion process adhere | attaches the surface of an optical device wafer to the protective tape as a protective member mounted in an annular frame, The said back surface grinding process and wafer rupture process in the state which stuck the surface of the optical device wafer to the said protective tape. Is carried out.

After performing the said wafer breaking process, the deterioration layer removal process of grinding the back surface of the board | substrate of an optical device wafer and removing a deterioration layer is performed.

The said protective member adhesion process adhere | attaches the surface of an optical device wafer to the protective tape as a protective member mounted in an annular frame, and the said back surface grinding process and wafer rupture process in the state which stuck the surface of the optical device wafer to the said protective tape. And a deterioration layer removal step.

In the present invention, the altered layer forming step is performed before forming the optical device by forming the optical device layer on the surface of the substrate, so that the optical device layer is not damaged by the laser beam. In addition, since the deterioration layer forming step is performed in a thick state before grinding the back surface of the substrate constituting the optical device wafer to form a predetermined thickness, the light converging point of the laser beam can be easily positioned at a desired position.

In the present invention, after performing the altered layer forming step, the back surface grinding process is performed to form the thickness of the optical device wafer to a predetermined thickness, and the optical device wafer is broken along the street on which the altered layer is formed. The thickness of can be suppressed to a minimum and the productivity is improved.

1 is a perspective view illustrating an optical device wafer;
2 is a perspective view of a sapphire substrate constituting an optical device wafer;
3 is a perspective view of an essential part of a laser processing apparatus for performing a deterioration layer forming step in a method of processing an optical device wafer according to the present invention.
4 is an explanatory diagram of a deterioration layer forming step in a processing method of an optical device wafer according to the present invention.
Fig. 5 is an enlarged cross-sectional view showing a perspective view and an essential part of an optical device wafer manufactured by performing an optical device wafer forming step in the method for processing an optical device wafer according to the present invention.
Fig. 6 is a perspective view showing a state in which a protective member adhesion step in the processing method of an optical device wafer according to the present invention is performed and the surface of the wafer is adhered to a protective tape attached to an annular frame.
7 is an explanatory diagram of a back surface grinding step in the method of processing an optical device wafer according to the present invention.
It is sectional drawing which expands and shows the principal part of the optical device wafer in which the back surface grinding process was performed in the manufacturing method of the optical device wafer by this invention.
9 is a perspective view of a wafer breaking device for performing a wafer breaking step in the method of processing an optical device wafer according to the present invention.
10 is an explanatory diagram of a wafer breaking step in the optical device wafer processing method according to the present invention.
11 is an explanatory diagram of a deterioration layer removal step in the processing method of the optical device wafer according to the present invention.
It is sectional drawing which expands and shows the principal part of the optical device wafer in which the deterioration layer removal process was performed in the manufacturing method of the optical device wafer which concerns on this invention.
13 is an explanatory diagram of a wafer movement step in the method of processing an optical device wafer according to the present invention.
Fig. 14 is a perspective view of a pickup device for carrying out the pickup step in the method for processing an optical device wafer according to the present invention.
15 is an explanatory diagram of a pick-up step in the method for processing an optical device wafer according to the present invention;

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of the manufacturing method of the optical device by this invention is described in detail with reference to an accompanying drawing.

1, the perspective view of the optical device wafer manufactured by the manufacturing process in the manufacturing method of the optical device by this invention is shown. In the optical device wafer 2 shown in FIG. 1, the light emitting layer (epitaxial layer) 21 as an optical device layer made of a nitride semiconductor is formed on the surface of the substrate 20 having a thickness of 430 μm, for example, in a thickness of 5 to 10 μm. It is stacked. An optical device 23 such as a light emitting diode, a laser diode, or the like is formed in a plurality of regions partitioned by a plurality of streets 22 in which the light emitting layer (epitaxial layer) 21 is formed in a lattice shape. Moreover, the notch 201 which shows a crystal orientation is formed in the outer periphery of the board | substrate 20 which comprises the optical device wafer 2. Hereinafter, the method of manufacturing this optical device wafer 2 is demonstrated.

2, the perspective view of the board | substrate 20 which comprises the optical device wafer 2 is shown. The board | substrate 20 shown in FIG. 2 consists of the sapphire substrate formed in disk shape of 430 micrometers in thickness, for example, and the notch 201 which shows a crystal orientation is formed in the outer periphery.

When the optical device wafer 2 is manufactured by forming a plurality of optical devices 23 on the surface of the sapphire substrate 20 shown in FIG. 2, first, a laser beam having a wavelength transmissive to the substrate is applied to the back side of the substrate. The condensation point is located inside the substrate and irradiated to a region corresponding to the street, and a deterioration layer forming step is performed in which the deterioration layer is formed inside the substrate at a predetermined distance from the surface of the substrate. This altered layer formation process is performed using the laser processing apparatus 3 shown in FIG. The laser processing apparatus 3 shown in FIG. 3 has the chuck table 31 which hold | maintains a to-be-processed object, and the laser beam irradiation means 32 which irradiates a laser beam to the workpiece hold | maintained on the said chuck table 31. FIG. And an image pickup means 33 for picking up the workpiece held on the chuck table 31. The chuck table 31 is configured to attract and hold the workpiece, and can be moved in the machining feed direction indicated by the arrow X in FIG. 3 by a machining feeder (not shown). The conveying means can be made to move in the indexing conveyance direction shown by the arrow Y in FIG.

The laser beam irradiation means 32 includes a cylindrical casing 321 arranged substantially horizontally. In the casing 321, the pulse laser beam oscillation means provided with the pulse laser beam oscillator which is not shown in figure, and a repetition frequency setting means is arrange | positioned. At the distal end of the casing 321, a condenser 322 for condensing the pulsed laser beams oscillated from the pulsed laser beam oscillation means is mounted. Moreover, the laser beam irradiation means 32 is provided with condensing point position adjusting means (not shown) for adjusting the condensing point position of the pulsed laser beam condensed by the condenser 322. As shown in FIG.

The imaging means 33 attached to the distal end of the casing 321 constituting the laser beam irradiation means 32 is constituted by an imaging device (CCD) or the like which imaged by visible light in the illustrated embodiment. The captured image signal is sent to control means (not shown). Moreover, in the memory of the control means which is not shown in figure, the coordinate value (design value) of the some street 22 formed in grid | lattice form on the surface of the board | substrate 20 which comprises the optical device 23 shown in the said FIG. Is stored.

In order to perform the said deterioration layer formation process using the above-mentioned laser processing apparatus 3, the surface 20a side of the sapphire substrate 20 is mounted on the chuck table 31 as shown in FIG. The sapphire substrate 20 is held on the chuck table 31 by operating suction means (not shown) (wafer holding step). Therefore, as for the sapphire substrate 20 hold | maintained by the chuck table 31, the back surface 20b becomes an upper side.

After the above-described wafer holding step, the chuck table 31 that sucks and holds the sapphire substrate 20 is positioned directly under the imaging means 33 by a processing transfer means (not shown). When the chuck table 31 is located directly under the imaging means 33, the alignment operation of whether the sapphire substrate 20 is located at a predetermined coordinate value by the imaging means 33 and a control means (not shown) is performed. Run That is, the imaging means 33 image | photographs the notch 201 formed in the outer periphery of the sapphire substrate 20, and sends the image signal to the control means which is not shown in figure. The control means (not shown) determines whether or not the notch 201 is located at a predetermined coordinate value based on the image signal sent from the imaging means 33, so that the notch 201 is not positioned at the predetermined coordinate value. If not, the chuck table 31 is rotated to adjust the notch 201 to be positioned at a predetermined coordinate value (alignment process).

If the alignment process was performed as mentioned above, as shown in FIG.4 (a), the chuck table 31 is moved to the laser beam irradiation area | region in which the condenser 322 of the laser beam irradiation means 32 is located, Coordinate values corresponding to one end (the left end in FIG. 4A) of the predetermined street 22 are positioned immediately below the light collector 322 of the laser beam irradiation means 32. And the condensing point P of the pulsed laser beam irradiated from the condenser 322 is adjusted to the position of 55 micrometers upper side from the surface 20a (lower surface) of the sapphire substrate 20, for example. In order to position the condensing point P of the pulsed laser beam irradiated from the condenser 322 at a predetermined position of the sapphire substrate 20, it is held in the chuck table described in, for example, Japanese Patent Laid-Open No. 2009-63446. Using the height position detection device of the workpiece, the height position of the upper surface of the sapphire substrate 20 held on the chuck table 31 is detected and shown on the basis of the detected height position of the upper surface of the sapphire substrate 20. The condensing point position of the pulsed laser beam is positioned at a predetermined position by operating the condensing point position adjusting means that is not provided. Next, the chuck table 31 is predetermined in the direction indicated by the arrow X1 in FIG. 4A while irradiating the sapphire substrate 20 with a pulsed laser beam having a transmittance from the light collector 322. Move at the machining feed rate. And as shown in FIG.4 (b), the irradiation position of the condenser 322 of the laser beam irradiation means 32 corresponds to the other end of the street 22 (right end in FIG.4 (b)). When the value is reached, the irradiation of the pulsed laser beam is stopped and the movement of the chuck table 31 is stopped. As a result, in the sapphire substrate 20, as shown in FIGS. 4B and 4C, a continuous deterioration layer 210 is formed along the region corresponding to the street 22. (Denatured layer forming step). The altered layer 210 is formed on the rear surface 20b (upper surface) side than the surface 20a (lower surface) of the sapphire substrate 20. The above-described altered layer forming process is performed along the regions corresponding to all the streets 22 formed on the optical device wafer 2.

The processing conditions in the above-described altered layer forming step are set as follows, for example.

Light source: Yb laser: Ytterbium-doped fiber laser

Wavelength: 1045 nm

Repetition frequency: 100 kHz

Average power: 0.3 W

Condensing spot diameter: φ1 to 1.5 μm

Machining feed rate: 400 mm / sec

When the above-described altered layer forming process is performed under the above processing conditions, the altered layer 210 having a thickness of about 50 μm is formed in the vertical direction around the light converging point P of the pulsed laser beam. Therefore, by performing the above-described deterioration layer forming process, the deterioration layer 210 having a thickness of about 50 μm is formed on the back surface 20b (upper surface) at a position of 30 μm from the surface 20a (lower surface) of the sapphire substrate 20. Is formed. In addition, the altered layer 210 formed inside the sapphire substrate 20 is preferably formed on the back surface 20b side at a position of 5 to 60 µm from the surface 20a of the sapphire substrate 20. As described above, in the altered layer forming step, the light emitting layer (epitaxial layer) 21 is formed on the surface of the sapphire substrate 20 before the optical device 23 is formed. (21) is not damaged. In addition, since the deterioration layer formation process is performed in the thick state (for example, 430 micrometers) before grinding the back surface and forming it in predetermined thickness, the sapphire substrate 20 which comprises the optical device wafer 2 is mentioned later, The condensing point P of the pulsed laser beam can be easily positioned at a desired position.

Next, the optical device layer is laminated on the surface 20a of the sapphire substrate 20 subjected to the above-described deterioration layer forming step, and the optical device is formed in a plurality of regions partitioned by a plurality of streets formed in a lattice shape. The optical device wafer formation process which comprises a device wafer is performed. This optical device wafer formation process can be performed by the method disclosed by Unexamined-Japanese-Patent No. 34409201, for example. By performing the optical device wafer forming step in this manner, as shown in FIGS. 5A and 5B, the surface 20a of the sapphire substrate 20 subjected to the above-described deterioration layer forming step is performed. The optical device wafer 2 in which the optical device 23 was formed in the several area | region divided | segmented by the some street 22 formed in the lattice form by laminating | stacking the light emitting layer (epi layer) 21 as an optical device layer is manufactured. . In the sapphire substrate 20 of the optical device wafer 2 configured as described above, a deterioration layer 210 is formed along a plurality of streets 22 formed in a lattice shape.

If the above-mentioned optical device wafer formation process was performed, in order to protect the optical device formed in the surface of an optical device wafer, the protective member adhesion process of sticking a protective member to the surface of an optical device wafer is performed. That is, as shown in Fig. 6, the surface 2a of the optical device wafer 2 is adhered to the surface of the protective tape 40 as the protective member attached to the annular frame 4 formed of the metal material. In the illustrated embodiment, the protective tape 40 is coated with an acrylic resin paste having a thickness of about 5 μm on the surface of a sheet base material made of polyvinyl chloride (PVC) having a thickness of 100 μm. The glue which has the property that adhesive force falls by irradiating an ultraviolet-ray is used.

When the surface 2a of the optical device wafer 2 is adhered to the protective tape 40 attached to the annular frame 4 by performing the above-mentioned protective member adhesion process, the back surface of the optical device wafer is ground and predetermined The back surface grinding step to be formed in thickness is performed. This back surface grinding process is performed using the grinding apparatus 5 shown in FIG. The grinding apparatus 5 shown in FIG. 7 is a grinding tool provided with the chuck table 51 which hold | maintains a workpiece | work, and the grinding grindstone 521 for grinding the workpiece hold | maintained by the said chuck table 51 ( 52). In addition, the chuck table 51 has a central portion holding the workpiece to be high, and an outer circumferential portion being formed lower than the central portion. In order to perform the said back grinding process using the grinding apparatus 5 comprised in this way, as shown in FIG. 7, the above-mentioned deterioration layer formation process on the chuck table 51 of the grinding apparatus 5 was performed. On the chuck table 51 by loading the protection tape 40 side of the device wafer 2, loading the annular frame 4 on the outer circumference of the chuck table 51, and operating suction means (not shown). The optical device wafer 2 and the annular frame 4 are sucked and held. Therefore, as for the optical device wafer 2 hold | maintained on the chuck table 51, the back surface 20b of the sapphire substrate 20 becomes an upper side. In this way, if the optical device wafer 2 is attracted and held on the chuck table 51, the grinding tool 52 is rotated at, for example, 1000 rpm, while the chuck table 51 is rotated at, for example, 500 rpm. By contacting the back surface 20b of the sapphire substrate 20 constituting the optical device wafer 2, a predetermined amount is ground and transferred. As a result, the back surface 20b of the sapphire substrate 20 is ground, and the sapphire substrate 20 constituting the optical device wafer 2 is formed to a predetermined thickness (for example, 80 µm). As a result, the deteriorated layer 210 can be exposed to the back surface 20b of the sapphire substrate 20 constituting the optical device wafer 2 as shown in FIG. 8. In this manner, after performing the above-described deterioration layer forming step, the backside grinding step is performed to form the thickness of the wafer to a predetermined thickness, whereby the thickness of the deteriorating layer can be suppressed to a minimum, thereby improving productivity.

If the above-mentioned back surface grinding process was performed, the wafer breaking process which gives an external force to an optical device wafer, breaks a wafer along the street in which the altered layer was formed, and divides into individual optical devices is performed. This wafer breaking step is performed using the wafer breaking device 6 shown in FIG. The wafer breaking device 6 shown in FIG. 9 is provided with the base 61 and the movement table 62 arrange | positioned so that the movement to the direction shown by the arrow Y on the base 61 is possible. The base 61 is formed in rectangular shape, and the two guide rails 611 and 612 are arrange | positioned in parallel to each other in the direction shown by the arrow Y on the upper surface of both sides. The movement table 62 is arrange | positioned on these two guide rails 611 and 612 so that a movement is possible. The movement table 62 can be made to move to the direction shown by the arrow Y by the movement means 63. FIG. On the movable table 62, frame holding means 64 for holding the annular frame 4 is arranged. The frame holding means 64 includes a cylindrical main body 641, an annular frame holding member 642 provided at an upper end of the main body 641, and fixing means disposed on an outer circumference of the frame holding member 642. A plurality of clamps 643 are included. The frame holding means 64 configured in this manner fixes the annular frame 4 mounted on the frame holding member 642 with the clamp 643. In addition, the wafer rupture apparatus 6 shown in FIG. 9 is provided with the rotation means 65 which makes the said frame holding means 64 rotate. The rotation means 65 includes a pulse motor 651 disposed on the movement table 62, a pulley 652 attached to a rotation shaft of the pulse motor 651, the pulley 652 and a cylindrical main body. And an endless belt 653 wound around 641. The rotating means 65 configured as described above rotates the frame holding means 64 through the pulley 652 and the endless belt 653 by driving the pulse motor 651.

The wafer breaking device 6 shown in FIG. 9 is an optical device wafer 2 supported by an annular frame 4 held by the annular frame holding member 642 via a protective tape 40. ) Is provided with tension imparting means (66) for exerting a tensile force in a direction orthogonal to the street (22). The tension applying means 66 is disposed in the annular frame holding member 642. This tension provision means 66 is equipped with the 1st suction holding member 661 and the 2nd suction holding member 662 which have a rectangular holding surface long in the direction orthogonal to the arrow Y direction. A plurality of suction holes 661a are formed in the first suction holding member 661, and a plurality of suction holes 662a are formed in the second suction holding member 662. The plurality of suction holes 661a and 662a communicate with suction means (not shown). In addition, the 1st suction holding member 661 and the 2nd suction holding member 662 can be made to move to arrow Y direction by the movement means not shown, respectively.

The wafer breaking device 6 shown in FIG. 9 is an optical device wafer 2 supported by an annular frame 4 held by the annular frame holding member 642 via a protective tape 40. Detection means 67 for detecting the street 22 of (). The detection means 67 is attached to the L-shaped support pillar 671 disposed on the base 61. This detection means 67 is comprised with an optical system, an imaging element (CCD), etc., and is arrange | positioned in the upper position of the said tension provision means 66. As shown in FIG. The detection means 67 comprised in this way is the street of the optical device wafer 2 supported by the annular frame 4 hold | maintained at the said annular frame holding member 642 via the protective tape 40. As shown in FIG. An image of 22 is converted into an electrical signal and sent to a control means (not shown).

The breaking of the wafer performed using the wafer breaking device 6 described above will be described with reference to FIG. 10.

As shown in FIG. 10A, the frame holding member 642 supports an annular frame 4 which supports the optical device wafer 2 subjected to the alteration layer forming process via the protective tape 40. It is mounted on the top and fixed to the frame holding member 642 by the clamp 643. Next, the moving means 63 is operated to move the moving table 62 in the direction indicated by the arrow Y (see FIG. 9), and as shown in FIG. 10A, the optical device wafer 2. The holding surface and the second suction holding of the first suction holding member 661 constituting the tension imparting means 66 for one street 22 (the leftmost street in the illustrated embodiment) formed in the predetermined direction. It is positioned between the holding surfaces of the member 662. At this time, the detection means 67 captures the street 22, and performs alignment between the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662. In this way, if one street 22 is positioned between the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662, the suction means (not shown) is operated to obtain the suction hole ( By applying negative pressure to 661a and 662b, the optical device wafer 2 is provided on the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662 via a protective tape 40. Is sucked and maintained (maintenance step).

After the above-described holding step is performed, the moving means (not shown) constituting the tension applying means 66 is operated, so that the first suction holding member 661 and the second suction holding member 662 are shown in Fig. 10B. As shown in the figure, the movement is performed in a direction away from each other. As a result, a tensile force acts on the street 22 located between the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662 in a direction orthogonal to the street 22. In the optical device wafer 2, the deteriorated layer 210 formed on the sapphire substrate 20 is broken along the street 22 as a starting point of breaking (breaking step). By performing this breaking process, the protective tape 40 is extended slightly. In this breaking process, since the deterioration layer 210 is formed along the street 22 and the intensity | strength is reduced, the optical device wafer 2 has the 1st suction holding member 661 and the 2nd suction holding member ( By moving the 662 by about 0.5 mm in the direction away from each other, the deteriorated layer 210 formed on the sapphire substrate 20 can be broken along the street 22 by breaking the optical device wafer 2. .

If the breaking process of breaking along one street 22 formed in the predetermined direction as mentioned above was performed, the optical device wafer 2 by the above-mentioned 1st suction holding member 661 and the 2nd suction holding member 662 was performed. Release suction). Next, the moving means 63 is operated to move the moving table 62 in the direction indicated by the arrow Y (see Fig. 9) by the amount corresponding to the distance between the streets 22, and the breaking step is performed. The street 22 next to (22) is positioned between the holding surface of the first suction holding member 661 constituting the tension applying means 66 and the holding surface of the second suction holding member 662. Then, the holding step and the breaking step are performed.

As described above, when the above holding step and the breaking step have been performed for all the streets 22 formed in the predetermined direction, the rotating means 65 is operated to rotate the frame holding means 64 by 90 degrees. As a result, the optical device wafer 2 held by the frame holding member 642 of the frame holding means 64 also rotates by 90 degrees, which is formed in a predetermined direction and is orthogonal to the street 22 where the breaking process is performed. The street 22 formed in the direction is positioned in parallel with the holding surface of the first suction holding member 661 and the holding surface of the second suction holding member 662. Next, by performing the above-described holding process and breaking process for all the streets 22 formed in the direction orthogonal to the street 22 where the breaking process is performed, the optical device wafer 2 is along the street 22. It is divided into individual optical devices 23.

After the above-described wafer breaking step is performed, the deteriorated layer removing step of grinding the back surface of the optical device wafer to remove the deteriorated layer is performed. This deterioration layer removal process is performed using the grinding apparatus 5 shown in the said FIG. That is, as shown in FIG. 11, the optical device wafer 2 (divided into individual optical devices 23) in which the above-mentioned wafer breaking process was performed on the chuck table 51 of the grinding apparatus 5 was performed. On the optical device wafer 2 on the chuck table 51 by loading the protective tape 40 side, loading the annular frame 4 on the outer circumference of the chuck table 51, and operating suction means (not shown). And retains the annular frame 4 by suction. Therefore, as for the optical device wafer 2 hold | maintained on the chuck table 51, the back surface 20b of the sapphire substrate 20 becomes an upper side. In this way, if the optical device wafer 2 is attracted and held on the chuck table 51, the grinding tool 52 is rotated at, for example, 1000 rpm, while the chuck table 51 is rotated at, for example, 500 rpm. By contacting with the back surface 20b of the sapphire substrate 20 constituting the optical device wafer 2, a predetermined amount is ground and transported to a position where the deteriorated layer 210 is removed. As a result, the back surface 20b of the sapphire substrate 20 which comprises the optical device wafer 2 is ground, and the deterioration layer which remained in the side surface of the optical device 23 divided | segmented individually as shown in FIG. 210 can be removed. In this way, the deterioration layer 210 remaining on the side of the optical device 23 divided separately can be removed, thereby improving the brightness of the optical device 23.

After performing the above-described deterioration layer removal process, the back surface of the optical device wafer divided into individual optical devices is adhered to the surface of the protective tape attached to the annular frame, and the protective tape having the surface of the optical device wafer adhered thereto. The wafer transfer process of peeling the 40 to remove the annular frame 4 is performed. In this wafer movement step, as shown in Fig. 13A, a protective tape 40 (optical device wafer 2 divided into individual optical devices 23) mounted on an annular frame 4 is provided. Adhered] is irradiated with ultraviolet rays from the ultraviolet irradiator 400. As a result, the adhesive paste of the protective tape 40 can harden | cure, and adhesive force may fall. Next, as shown in FIG. 13B, the back surface of the sapphire substrate 20 constituting the optical device wafer 2 adhered to the protective tape 40 attached to the annular frame 4 ( 20b) (the upper surface in FIG. 13 (b)) is adhered to the surface of the protective tape 40a (lower surface in FIG. 13 (b)) attached to the annular frame 4a. In addition, the annular frame 4a and the protective tape 40a should just be the structure substantially the same as the said annular frame 4 and the protective tape 40. FIG. Next, as shown in FIG. 13C, the optical device wafer 2 (divided into individual optical devices 22) having a surface adhered to the protective tape 40 is provided with the protective tape 40. Peel off from. At this time, since the ultraviolet-ray is irradiated to the protective tape 40, the adhesive paste of the protective tape 40 hardens | cures, and adhesive force is reduced as shown to FIG. 13 (a), the optical device wafer 2 (individually) Can be easily separated from the protective tape 40]. Then, by removing the annular frame 4 on which the protection tape 40 is attached, the surface of the protection tape 40a mounted on the annular frame 4a as shown in FIG. 13 (d) is removed. The optical device wafer 2 divided into individual devices is moved. As described above, the wafer transfer step is performed by performing the back grinding step, the wafer breaking step, and the deterioration layer removal step in a state in which the wafer surface is adhered to the protective tape 40 attached to the annular frame 4. Since the device wafer 2 is divided into individual devices 22 and then carried out, the front and rear surfaces are reversed without breaking the optical device wafer 2 and replaced with the protective tape 40a mounted on the annular frame 4a. Can be attached Therefore, the conduction test of the optical device 23 is conducted in a state where the optical device wafer 2 divided into individual optical devices 23 is attached to the protective tape 40a attached to the annular frame 4a. can do.

If the wafer movement process was performed as mentioned above, the pick-up process of peeling and picking up the optical device divided | segmented individually from the protective tape which adhere | attached on the surface of the protective tape attached to the annular frame is performed. This pick-up process is performed using the pick-up apparatus 7 shown in FIG. The pick-up apparatus 7 shown in FIG. 14 is attached to the frame holding means 71 holding the said annular frame 4a, and the annular frame 4a hold | maintained by the said frame holding means 71. As shown in FIG. The tape extending means 72 which expands the said protective tape 40a, and the pickup collet 73 are provided. The frame holding means 71 includes an annular frame holding member 711 and a plurality of clamps 712 as fixing means arranged on the outer circumference of the frame holding member 711. The upper surface of the frame holding member 711 forms a mounting surface 711a for loading the annular frame 4a, and the annular frame 4a is mounted on the mounting surface 711a. And the annular frame 4a mounted on the mounting surface 711a is fixed to the frame holding member 711 by the clamp 712. As shown in FIG. The frame holding means 71 configured as described above is supported by the tape expansion means 72 so as to be able to move forward and backward.

The tape expansion means 72 is provided with the expansion drum 721 arrange | positioned inside the said annular frame holding member 711. This expansion drum 721 is smaller than the inner diameter of the annular frame 4a, and is mounted on the optical device wafer 2 (divided into individual optical devices 23) mounted on the annular frame 4a. It has an inner diameter and an outer diameter larger than the outer diameter of. Moreover, the expansion drum 721 is provided with the support flange 722 at the lower end. The tape expansion means 72 in the shown embodiment is provided with the support means 723 which can advance and retract the said annular frame holding member 711 in an up-down direction. The support means 723 comprises a plurality of air cylinders 723a disposed on the support flange 722, the piston rod 723b of which is connected to the lower surface of the annular frame holding member 711. do. As described above, in the support means 723 including the plurality of air cylinders 723a, the loading surface 711a has an expansion drum 721 having an annular frame holding member 711 as shown in Fig. 15A. It moves between the reference position which becomes substantially the same height as the upper end of (), and the extended position of predetermined side lower than the upper end of the expansion drum 721 as shown to FIG. 15 (b).

The pick-up process performed using the pick-up apparatus 7 comprised as mentioned above is demonstrated with reference to FIG. That is, as shown in Fig. 15A, the annular frame 4a on which the protective tape 40a to which the optical device wafer 2 (divided into individual devices) is adhered is mounted. It mounts on the mounting surface 711a of the frame holding member 711 which comprises the holding means 71, and is fixed to the frame holding member 711 by the clamp 712 (frame holding process). At this time, the frame holding member 711 is located at the reference position shown in Fig. 15A. Next, the plurality of air cylinders 723a as the support means 723 constituting the tape expansion means 72 are operated to extend the annular frame holding member 711 in Fig. 15B. Descend to Therefore, since the annular frame 4a fixed on the mounting surface 711a of the frame holding member 711 also descends, as shown in Fig. 15B, the annular frame 4a is mounted. The mounted protective tape 40a can be brought into contact with the top edge of the expansion drum 721 (tape expansion process). As a result, since the optical device wafer 2 adhering to the protective tape 40a is divided into individual optical devices 23 along the street 21, the space between the individual devices 23 becomes wider and spaces apart. (S) is formed. In this state, the pick-up collet 73 is operated to adsorb and hold the surface (upper surface) of the optical device 23, and to pick up by peeling off the protective tape 40a. At this time, as shown in FIG.15 (b), the optical device 23 is pushed up by the push-up needle 74 from the lower side of the protection tape 40a, and the optical device 23 is protected by the protection tape 40a. It can be easily peeled from. Since the push-up needle 74 acts on the back surface of the optical device 22 and pushes it up, the surface of the optical device 23 is not damaged. Moreover, in the pick-up process, since the clearance gap S between each optical device 23 is widened as mentioned above, it can pick up easily, without contacting the adjacent optical device 23. In this way, the optical device 23 picked up by the pickup collet 73 does not need to reverse the front and back of the optical device 23 after the surface (upper surface) is adsorbed and held.

As mentioned above, although demonstrated based on embodiment which showed this invention, this invention is not limited only to embodiment, A various deformation | transformation is possible in the range of the meaning of this invention. For example, in the above-described embodiment, although the tensile force acts in a direction orthogonal to the street on which the deterioration layer is formed as the starting point of the break as a wafer breaking step, the wafer is broken along the street on which the deterioration layer is formed. As the process, for example, as disclosed in Japanese Patent Laid-Open No. 2006-107273 or Japanese Patent Laid-Open No. 2006-128211, a bending stress is applied along a street to a wafer whose strength has been reduced along the street and the wafer is brought into a street. Other breaking methods may be used, such as breaking along the wire.

2: optical device wafer 20: sapphire substrate
21: Light emitting layer (epi layer) as a device layer 3: Laser processing apparatus
31: chuck table of the laser processing apparatus 32: laser beam irradiation means
322 condenser 4: annular frame
40: protection tape 5: grinding device
51: chuck table of the grinding device 52: grinding tool
6: wafer breaking device 66: tensioning means
7: pickup device 82: tape expansion means
73: pickup collet

Claims (5)

An optical device manufacturing method of dividing an optical device wafer having an optical device formed on a plurality of areas partitioned by a plurality of streets formed by lattice and laminating an optical device layer on a surface of a substrate into individual optical devices along a street.
A laser beam having a wavelength transmissive to the substrate is irradiated from the back side of the substrate to a region corresponding to a street by placing a light collecting point in the inside of the substrate, and having a predetermined distance from the surface of the substrate inside the substrate at a predetermined interval. A deterioration layer forming step of forming a deterioration layer in the
An optical device wafer forming step of forming an optical device wafer by laminating an optical device layer on a surface of the substrate subjected to the deterioration layer forming step and forming the optical device in a plurality of regions partitioned by a plurality of streets formed in a lattice shape; ,
A protective member adhesion step of adhering the protective member to the surface of the optical device wafer,
A back surface grinding step of grinding the back surface of the substrate of the optical device wafer to form a predetermined thickness;
Wafer breaking step of applying an external force to the optical device wafer subjected to the back grinding process, breaking the optical device wafer along the street on which the deterioration layer is formed, and dividing the optical device wafer into individual optical devices.
Method of manufacturing an optical device comprising a. The manufacturing method of the optical device of Claim 1 in which the predetermined space | interval from the surface of the board | substrate in the said deterioration layer formation process is set to 5-60 micrometers. The said protective member adhesion process of Claim 1 or 2 adhere | attaches the surface of an optical device wafer to the protective tape as a protective member attached to the annular frame, and adhere | attached the surface of an optical device wafer to the said protective tape. The manufacturing method of the optical device which performs the said back surface grinding process and a wafer breaking process in a state. The manufacturing method of the optical device of Claim 1 or 2 which performs the deterioration layer removal process which grinds the back surface of the board | substrate of an optical device wafer, and removes a deterioration layer after performing the said wafer breaking process. 5. The back surface of claim 4, wherein the protective member adhesion step adheres the surface of the optical device wafer to a protective tape as a protective member attached to an annular frame and adheres the surface of the optical device wafer to the protective tape. The manufacturing method of an optical device which performs a grinding process, a wafer rupture process, and a deterioration layer removal process.

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