TWI392002B - Laser processing device - Google Patents

Description

Laser processing device

The present invention relates to a laser processing apparatus that performs specific processing by irradiating a specific area of a workpiece with laser light.

In the semiconductor device manufacturing process, a semiconductor wafer in which a plurality of ICs such as ICs and LSIs are formed in a matrix form is formed by laminating a surface layer of an insulating film and a functional film on a surface area of a semiconductor substrate such as germanium. The semiconductor wafer formed in this manner is divided into the above-described devices by a predetermined dividing line called a block, and each semiconductor wafer can be manufactured by cutting along the block. Further, a plurality of regions are divided by a lattice-shaped block formed on a surface of a sapphire substrate or the like, and a gallium nitride-based compound semiconductor or the like is laminated in the divided region to form an optical device wafer of the optical device. The block is divided into optical devices such as light-emitting diodes and laser diodes, and is widely used in electrical machines.

Such cutting along a block of a wafer such as a semiconductor wafer or an optical device wafer is usually carried out using a cutting device called a dicer. The cutting device includes: a chuck table for holding a wafer of workpieces; a cutting means for cutting a wafer held by the chuck table; and a moving means for relatively moving the chuck table and the cutting means . The cutting means includes a rotating shaft that can rotate at a high speed, and a cutting tool mounted on the rotating shaft. The cutting tool is composed of a disk-shaped base and an annular cutting edge mounted on the outer edge portion of the side surface of the base. The cutting edge is, for example, electroformed to fix diamond abrasive grains having a particle diameter of about 3 μm. The thickness is formed to a thickness of 20 μm. The cutting of the wafer is performed by the cutting tool, and the cut surface of the cut wafer is notched or cracked, and the influence of the notch or the crack is estimated to form the width of the block by 50 μm. Therefore, when the size of the semiconductor wafer is reduced, the proportion of the block in the wafer becomes large, which is a cause of lowering productivity. In addition, when cutting with a cutting tool, there is a limit to the feed rate, and there is a problem that chips may contaminate the wafer.

In addition, in order to form a finer device such as an IC or an LSI, an inorganic material film such as SiOF or BSG (SiOB) or a polyimide film is laminated on the surface of a semiconductor wafer main body such as a silicon wafer. a semiconductor wafer in the form of a low dielectric constant insulator (Low-k film) composed of a film of an organic film such as a polyparaphenylene polymer film, and a metal called a test element group (Teg) Patterned semiconductor wafers have been put to practical use. When a semiconductor wafer in which a low dielectric constant insulator (Low-k film) is laminated is cut along a block by a cutting tool, there is a problem that the low dielectric constant insulator is peeled off. Further, when a semiconductor wafer having a metal pattern called a test element group (Teg) is cut along a block by a cutting tool, since the metal pattern is formed of a viscous metal such as copper, a burr may occur. The problem.

On the other hand, in recent years, a method of dividing a plate-shaped workpiece such as a semiconductor wafer, such as irradiating a pulsed laser beam along a block formed in a workpiece, forms a laser processing groove, and a mechanical brake device is used. A method of cutting the laser processing groove (for example, refer to Patent Document 1).

[Patent Document 1] Japanese Patent Laid-Open No. Hei 10-305420

Laser processing is faster than machining, and wafer processing consisting of high-hardness materials from sapphire is easier. In addition, the method of irradiating the laser light to form the laser processing groove not only solves the problem of peeling of the low dielectric constant insulator layer, but also solves the problem of occurrence of burrs. However, the laser light is irradiated along the block of the wafer, and the thermal energy concentrates the irradiated area to generate debris, which causes a new problem that the chip adheres to the surface of the wafer to reduce the quality of the wafer.

In order to solve the problems caused by the above-mentioned debris, the following method has been proposed, that is, a protective film covering a processed surface of a wafer, such as polyvinyl alcohol, and a laser beam irradiated with a laser beam through a protective film; Method (for example, refer to Patent Document 2).

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2004-188475

In this way, the protective film forming device that covers the protective film on the processing surface of the workpiece, and the laser processing device that irradiates the workpiece with the laser beam through the protective film, in terms of the space of the factory, Or, in terms of transferring the workpiece between the devices, the efficiency requirements are not met.

Therefore, a laser processing apparatus having a protective film formation and cleaning means capable of covering a protective film on a processed surface of a workpiece and capable of washing the protective film after laser processing has been proposed (for example, see Patent Document 3) .

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2004-322168

However, the protective film forming and cleaning means of the laser processing apparatus described in the above publication has the function of covering the protective surface of the processed surface of the workpiece and the function of washing the protective film after the laser processing. During the cleaning of the workpiece after the laser processing, the protective layer of the next workpiece cannot be covered. Therefore, it is necessary to apply a protective film covering process, a laser processing process, and a cleaning process to one workpiece before performing a protective film covering process on the next workpiece, and therefore, the processing efficiency is not good.

In view of the above facts, the main technical object of the present invention is to provide a laser processing apparatus comprising: a function of covering a protective surface of a processed surface of a workpiece, and a function of washing the protective film after laser processing, and , processing efficiency is good.

In order to solve the above-mentioned main technical problems, the laser processing apparatus of the present invention includes: a chuck table for holding a workpiece; and a laser beam for irradiating the workpiece to be held by the chuck table with laser light. Irradiation means; a cassette mounting table for loading a cassette containing the workpiece; and a loading and unloading means for carrying out the loading and unloading of the workpiece for the cassette placed on the cassette mounting table; A temporary placement table for temporarily storing a workpiece to be carried out by the loading/unloading means, the laser processing apparatus characterized by: arranging a workpiece before being processed to be transported to the temporary placement table to be transported to a first transport path of the chuck table, a protective film forming means for covering the protective film on the processed surface of the workpiece before processing; and a workpiece to be processed after being processed in the chuck table The second transport path that is transported to the temporary placement table, the cleaning means for removing the protective film covering the processed surface of the processed object after processing, and the processed material before being processed to be transported to the temporary placement table to The protective film forming means, the first transfer means for transporting the processed object subjected to the cleaning process by the cleaning means to the temporary placement stage; and the protective cover film forming means The workpiece before the film coating is conveyed to the chuck table, and the processed object held by the chuck table is transported to the second transport means of the cleaning means.

In the laser processing apparatus of the present invention, the protective film forming means and the cleaning means are provided, and the workpiece to be processed by the laser beam irradiation process can be conveyed to the protection process while the processing of the object to be processed by the laser beam irradiation process is performed. The film forming means and the protective film covering process are implemented, so that the production efficiency can be improved.

Hereinafter, a preferred embodiment of a laser processing apparatus having the configuration of the present invention will be described in detail with reference to the drawings.

Fig. 1 is a perspective view of a laser processing apparatus having the constitution of the present invention.

The laser processing apparatus shown in Fig. 1 includes a device housing 2 having a substantially rectangular parallelepiped shape. In the apparatus casing 2, a chuck table 3 for holding a workpiece holding means for holding a workpiece is disposed so as to be movable in a direction indicated by an arrow X in the machining feed direction. The chuck table 3 includes: an adsorption chuck support table 31; and an adsorption chuck 32 mounted on the adsorption chuck support table 31, and the workpiece can be, for example, a disk shape by means of an unillustrated attraction means The semiconductor wafer is held on the mounting surface of the surface of the chuck 32. Further, the configuration of the chuck table 3 can be rotated by a rotating mechanism not shown. The chuck holder 33 having the above-described configuration of the chuck table 3 is provided with a jig 33 for fixing an annular frame to be described later.

The laser processing apparatus shown in the drawing includes a laser beam irradiation means 4 for irradiating a workpiece to be held on the chuck 32 of the chuck table 3 with a laser beam. The laser beam irradiation means 4 includes a cylindrical casing 41 which is substantially horizontally arranged. In the housing 41, a pulsed laser ray oscillating means having a pulsed laser ray oscillator composed of a YAG laser oscillator or a YVO4 laser oscillator, or a repetition frequency setting means, not shown, is disposed. . At the front end of the casing 41, a concentrator 42 for collecting light of pulsed laser light from the oscillation of the pulsed laser beam oscillating means is mounted.

The laser processing apparatus shown in the drawing includes a surface of a workpiece to be held by the chuck 32 of the chuck table 3, and is detected by the concentrator 42 to be irradiated by the laser beam irradiation means 4. A means of photography 5 in the area where laser light is processed. In addition to the normal imaging element (CCD) that is captured by visible light rays, the imaging means 5 is an infrared illumination means that irradiates the workpiece with infrared rays, and infrared rays that are used to extract the infrared illumination means. The optical system and the photographic element (infrared CCD) for outputting an electrical signal corresponding to the infrared ray extracted by the optical system are used, and the taken image signal is transmitted to a control means not shown. Further, the wafer dividing device shown in the figure includes a display means 6 for displaying an image taken by the imaging means 5.

The laser processing apparatus shown in the drawing includes a cassette mounting portion 13a for placing a cassette of a semiconductor wafer 10 in which a workpiece is placed. The cassette mounting portion 13a is provided with a cassette table 131 so as to be movable up and down by means of a lifting means not shown, and the cassette 13 is placed on the cassette table 131. The semiconductor wafer 10 is attached to the surface of the protective tape 12 mounted on the annular frame 11, and is accommodated in the cartridge 13 in a state in which the protective tape 12 is supported by the annular frame 11. Further, as shown in FIG. 8, the surface 10a of the semiconductor wafer 10 is divided into a plurality of regions by a lattice-shaped plural dividing line 101, and devices 102 such as ICs and LSIs are formed in the divided regions. As shown in FIG. 1, the semiconductor wafer 10 constructed in this manner is attached to the protective tape 12 attached to the annular frame 11 with the front surface 10a as the upper side and the back surface.

The illustrated laser processing apparatus includes: a semiconductor wafer 10 for processing before being processed from the cassette 13 and a workpiece loading/unloading means 14 for loading and processing the semiconductor wafer 10; A temporary placement table 15 for temporarily arranging the semiconductor wafer 10 before processing by the workpiece carry-in/out device 14; and a semiconductor wafer 10 before being processed for transport to the temporary placement table 15 is transported to the chuck a protective film forming means 7 for covering the protective surface of the processed surface of the semiconductor wafer 10 before processing in the first transfer path of the stage 3; and a semiconductor crystal disposed after processing on the chuck stage 3 The circle 10 is transported to the second transfer path of the temporary placement stage 15 for cleaning and cleaning the cleaning means 8 for removing the protective film covering the processed surface of the processed semiconductor wafer 10. Further, it is important that the first transport path and the second transport path are different transport paths. Further, the laser processing apparatus shown in the drawing includes a semiconductor in which the semiconductor wafer 10 before being processed and transported to the temporary placement stage 15 is transferred to the protective film forming means 7 and processed by the cleaning means 8 The wafer 10 is transferred to the first transfer means 16 of the temporary placement stage 15; and the semiconductor wafer 10 before the processing for covering the protective film by the protective film forming means 7 is transferred to the chuck table 3, and is held by The semiconductor wafer 10 after the processing of the chuck table 3 is transferred to the second transfer means 17 of the cleaning means 8.

Next, the protective film forming means 7 will be described with reference to Figs. 2 to 4 .

The protective film forming means 7 of the embodiment shown in the drawings includes a rotary table mechanism 71 and a rotary table housing means 72 disposed around the rotary table mechanism 71. The rotary table mechanism 71 includes a rotary table 711, an electric motor 712 for rotationally driving the rotary table 711, and a support mechanism 713 for supporting the electric motor 712 so as to be movable in the vertical direction. The rotary table 711 is provided with an adsorption chuck 711a formed of a porous material, and the adsorption chuck 711a is connected to an attraction means not shown. Therefore, the turntable 711 holds the wafer on the chuck 711 by applying a negative pressure to the wafer of the workpiece placed on the chuck 711a by means of a suction means not shown. Further, a jig 714 for fixing the annular frame 11 is disposed on the turntable 711. The rotating table 711 is coupled to the upper end of the drive shaft 712 of the electric motor 712. The support mechanism 713 is a support leg 713 of a plurality of (three embodiments in the illustrated embodiment) and a plurality of support legs attached to the support leg 713 and mounted on the electric motor 712 (the embodiment shown in the figure is three) The cylinder 713b is constructed. The support mechanism 713 having such a configuration uses the operation of the air cylinder 713b to move the electric motor 712 and the rotary table 711 to the workpiece at the upper position shown in FIG. The working position of the unloading position and the lower position shown in Fig. 4.

The turntable housing means 72 includes a storage container 721, support legs 722 for supporting the three storage containers 721 (two in the second figure), and a cover member 723 attached to the drive shaft 712a of the electric motor 712. . The storage container 721 is composed of a cylindrical outer side wall 721a, a bottom wall 721b, and an inner side wall 721c shown in Figs. 3 and 4 . A hole 721d through which the drive shaft 712a of the electric motor 712 is inserted is disposed in a central portion of the bottom wall 721b, and an inner side wall 721c is formed to protrude upward from a periphery of the hole 721d. The cover member 723 is formed in a disk shape, and has a cover portion 723a that protrudes downward from the outer peripheral edge thereof. In the cover member 723 having such a configuration, when the electric motor 712 and the rotary table 711 are in the working position shown in FIG. 4, the cover portion 723a is overlapped with the gap to form the inner side wall of the storage container 721. Outside the 721c.

The protective film forming means 7 shown in the drawing includes a resin liquid supply means 74 for supplying a liquid resin to the surface of the semiconductor wafer 10 held by the workpiece before the processing of the turntable 711. The resin liquid supply means 74 includes a resin liquid supply nozzle 741 for supplying a liquid resin to the surface of the wafer before processing on the turntable 711, and a forward rotation for swinging the resin liquid supply nozzle 741. The reverse electric motor 742 and the resin liquid supply nozzle 741 are connected to a resin liquid supply source not shown. The resin liquid supply nozzle 741 is a nozzle portion 741a that is bent downward from the end portion before the horizontal extension, and a support portion 741b that extends downward from the base end of the nozzle portion 741a. The support portion 741b is inserted into the figure. The insertion hole is provided in a bottom wall 721b for constituting the storage container 721, and is connected to a liquid resin liquid supply source not shown. Further, a sealing member (not shown) for sealing between the support portion 741b and the periphery of the insertion hole not shown in the figure in which the support portion 741b of the resin liquid supply nozzle 741 is inserted is provided.

Next, the cleaning means 8 will be described with reference to Figs. 5 to 7 .

The cleaning means 8 of the embodiment shown in the drawings includes a rotary table mechanism 81 and a washing water receiving means 82 disposed around the rotary table mechanism 81. Similarly to the rotary table mechanism 71 of the protective film forming means 7, the rotary table mechanism 81 includes a rotary table 811, an electric motor 812 that rotationally drives the rotary table 811, and a support for the electric motor 812 that can be vertically moved. Agency 813. The rotary table 811 is formed of a porous material and includes an adsorption chuck 811a that communicates with a suction means not shown. Therefore, the rotary table 811 causes the negative pressure to act on the wafer of the workpiece placed on the chuck 811a by the suction means not shown in the drawing, and holds the wafer on the chuck 811. Further, the rotary table 811 is provided with a jig 814 for the purpose of fixing the annular frame 11 described above. The upper end of the drive shaft 812a of the electric motor 812 is coupled to the above-described rotary table 811. The support mechanism 813 is a support leg 813 of a plurality of (three embodiments in the illustrated embodiment) and a plurality of support legs attached to the support leg 813 and mounted on the electric motor 812 (the embodiment shown in the figure is three) The cylinder 813b is constructed. The support mechanism 813 having such a configuration is configured such that the electric motor 812 and the rotary table 811 are positioned to move the workpiece to the upper position shown in FIG. 6 by the operation of the air cylinder 813b, and the loading position and the lower position shown in FIG. The working position.

The washing water receiving means 82 includes: a washing water storage container 821; support legs 822 for supporting three (two in FIG. 5) of the washing water storage container 821; and the electric motor 812 installed in the electric motor 812 The cover member 823 of the drive shaft 812. The washing water storage container 821 is composed of a cylindrical outer side wall 821a, a bottom wall 821b, and an inner side wall 821c shown in Figs. 6 and 7 . A hole 821d through which the drive shaft 812a of the electric motor 812 is inserted is disposed at a central portion of the bottom wall 821b, and an inner side wall 821c is formed to protrude upward from a periphery of the hole 821d. Further, a drain port 821e is disposed in the bottom wall 821b shown in Fig. 6, and the drain port 821e is connected to the drain pipe 824. The cover member 823 is formed in a disk shape, and has a cover portion 823a that protrudes downward from the outer peripheral edge thereof. In the cover member 823 having such a configuration, when the electric motor 812 and the rotary table 811 are located at the working position shown in Fig. 7, the cover portion 823a is superposed on the washing water storage container 821 so as to form a gap. The outer side wall 821c is on the outer side.

The cleaning means 8 shown in the figure includes a washing water supply means 84 for washing the wafer of the workpiece to be processed by the processing of the rotary table 811. The washing water supply means 84 includes a washing water nozzle 841 for discharging the washing water held by the processed wafer on the rotary table 811, and a forward rotation for reversing the washing water nozzle 841. The electric motor 842 is connected to a washing water supply source not shown in the figure. The washing water nozzle 841 is a nozzle portion 841a that is bent downward at an end portion before horizontal extension, and a support portion 841b that extends downward from a base end of the nozzle portion 841a. The support portion 841b is inserted into the drawing. The unillustrated insertion hole is disposed in a bottom wall 821b for constituting the above-described washing water storage container 821, and is connected to a washing water supply source not shown. Further, a sealing member (not shown) for sealing between the support portion 841b and the periphery of the insertion hole not shown in the drawing through which the support portion 841b of the washing water nozzle 841 is inserted is provided.

The cleaning means 8 shown in the drawing includes a gas supply means 85 for blowing a gas to the surface of the wafer which has been cleaned by the rotary table 811. The gas supply means 85 includes a gas nozzle 851 for ejecting gas toward the wafer held on the rotary table 811, and a forward rotation for swinging the gas nozzle 851. The reversed electric motor (not shown) is connected to a gas supply source not shown on the drawing. The gas nozzle 851 is a nozzle portion 851a that is bent downward at an end portion before horizontal extension, and a support portion 851b that extends downward from a base end of the nozzle portion 851a. The support portion 851b is not shown in the figure. The through hole is disposed in a bottom wall 821b for constituting the above-described washing water storage container 821, and is connected to a gas supply source not shown. Further, a periphery of the insertion hole not shown in the drawing through which the support portion 851b of the gas nozzle 851 is inserted is provided with a seal (not shown) for sealing and the support portion 851b.

Next, the first conveying means 16 and the second conveying means 17 will be described with reference to Fig. 1 .

The first conveying means 16 is disposed at a position equidistant from the temporary placement table 15, the protective film forming means 7, and the cleaning means 8. The first conveying means 16 has the same configuration as that of the generally used conveying means, and includes a holding means 161 for sucking and holding the annular frame 11, and supporting the holding means 161 so as to be vertically movable and rotatable. Support means 162; The first transport means 16 having such a configuration can transport the semiconductor wafer 10 before being processed to the temporary placement stage 15 (attached to the surface of the protective tape 12 mounted on the annular frame 11) to the protective film. The forming means 7 can transport the semiconductor wafer 10 (attached to the surface of the protective tape 12 mounted on the annular frame 11) which has been subjected to the cleaning by the cleaning means 8 to the temporary placement table 15.

The second transfer means 17 is disposed at a position equidistant from the chuck table 3, the protective film forming means 7, and the cleaning means 8. The second transporting means 17 is substantially identical to the first transporting means 16, and is supported by the holding means 171 for sucking and holding the annular frame 11, and is rotatably supported in the vertical direction. The means 172 of the means 171; In the second transfer means 17 having such a configuration, the semiconductor wafer 10 before the processing for covering the protective film by the protective film forming means 7 can be attached (attached to the surface of the protective tape 12 provided on the annular frame 11). The state is transferred to the chuck table 3, and the processed semiconductor wafer 10 (attached to the surface of the protective tape 12 mounted on the ring frame 11) held by the chuck table 3 can be transported to the cleaning. Means 8.

The laser processing apparatus shown in the figure has the above configuration, and the operation will be described below.

As shown in Fig. 1, the semiconductor wafer 10 (hereinafter simply referred to as the semiconductor wafer 10) before processing by the annular frame 11 is obtained via the protective tape 12, and the surface 10a of the processed surface is placed on the upper side, and is accommodated in the cassette. 13 is the location. The pre-processed semiconductor wafer 10 accommodated at a predetermined position of the cassette 13 moves the cassette stage 131 up and down by a lifting means not shown, and is positioned at the carry-out position. Then, the workpiece loading/unloading means 14 performs the advance/retract movement, and the semiconductor wafer 10 positioned at the carry-out position is carried out to the temporary placement stage 15 disposed in the temporary placement portion 15a. A center alignment process for aligning the center position of the semiconductor wafer 10 that is carried out to the temporary placement stage 15 is performed. Then, the semiconductor wafer 10 before the processing for completing the center alignment by the temporary placement stage 15 is sucked and held by the holding means 161 of the first transfer means 16, and is transported by the rotation operation centered on the support means 162. The suction chuck 711a constituting the rotary table 711 of the protective film forming means 7 is suction-held by the suction chuck 711a (wafer holding process). Further, the ring frame 11 is fixed by a jig 714. At this time, the rotary table 711 is positioned at the workpiece loading/unloading position shown in FIG. 3, and the resin supply nozzle 741 is positioned at a standby position above the rotary table 711 shown in FIGS. 2 and 3 via a moderate distance. .

In addition to the wafer holding process for holding the semiconductor wafer 10 before processing on the rotating stage 711 of the protective film forming means 7, the rotating table 711 is positioned at the working position shown in FIG. 4 and driven. The electric motor 742 swings the resin liquid supply nozzle 741 around the support portion 741b, and positions the front end of the nozzle portion 741a at a position above the central portion of the surface 10a of the processing surface of the semiconductor wafer 10 held on the rotary table 711. . Next, the electric motor 712 is driven to rotate the turntable 711 (see FIG. 2) at a rotation speed of 300 to 1000 rpm. Therefore, the semiconductor wafer 10 held in the turntable 711 (attached to the surface of the protective tape 12 mounted on the ring frame 11) is rotated in the direction indicated by the arrow 70 in FIG. In the state where the semiconductor wafer 10 is rotated, the nozzle portion 741a of the resin liquid supply nozzle 741 shown in Fig. 9 is dropped to the central portion of the surface 10a (machined surface) of the semiconductor wafer 10 in about 30 seconds. A specific amount of the liquid resin 100. Further, the liquid resin 100 should be a water-soluble resist such as PVA (Poly Vinyl Alcohol), PEG (Poly Ethylene Glycol), or PEO (Poly Ethylene Oxide). As a result, the liquid resin 100 dropped to the central portion of the surface 10a (machined surface) of the semiconductor wafer 10 flows to the outer edge portion by the centrifugal force to cover the surface 10a of the semiconductor wafer 10. The liquid resin is cured as time passes, and a protective film 110 (protective film covering process) is formed on the surface 10a of the semiconductor wafer 10 shown in FIG. The thickness of the protective film 110 is determined by the amount of the liquid resin 100 dropped from the resin liquid supply nozzle 741, and is preferably about 1 to 10 μm.

After the protective film covering process is applied to the surface 10a of the processed surface of the semiconductor wafer 10 to cover the protective film 110, the rotating table 711 is positioned and moved into the workpiece shown in FIG. The position is moved out, and the suction holding of the semiconductor wafer 10 held by the turntable 711 is released. Then, the semiconductor wafer 10 on the holding rotary table 711 is sucked by the holding means 171 of the second transfer means 17 and transported to the chuck 32 of the chuck table 3 by the rotation operation centered on the support means 172. The suction chuck 32 performs suction holding. In this manner, the chuck table 3 holding the semiconductor wafer 10 is sucked and positioned at a position directly below the photographing means 5 disposed in the laser beam irradiation means 4 by means of a moving means not shown.

After the chuck table 3 is positioned directly below the photographing means 5, the block 101 formed in the specific direction of the semiconductor wafer 10 and the block 101 are irradiated by the photographing means 5 and the control means not shown on the drawing. The position of the concentrator 42 of the laser beam irradiation means 4 of the laser beam is aligned for the purpose of image processing such as pattern matching, and the alignment of the laser beam irradiation position is performed. Further, alignment of the same laser beam irradiation position is performed on the block 101 formed on the semiconductor wafer 10 at a right angle with respect to the specific direction. At this time, the protective film 110 is formed on the surface 10a of the block 101 on which the semiconductor wafer 10 is formed. When the protective film 110 is opaque, it can be aligned from the surface by infrared rays.

As described above, when the block 101 of the semiconductor wafer 10 held on the chuck table 3 is detected and the alignment of the laser beam irradiation position is performed, as shown in FIG. 11(a), the chuck table 3 is caused. The laser beam irradiation area where the concentrator 42 of the laser beam irradiation means 4 irradiating the laser light is moved, and the specific block 101 is positioned directly below the concentrator 42. At this time, as shown in FIG. 11(a), the semiconductor wafer 10 is positioned at one end of the block 101 (the left end of FIG. 11(a)) at a position directly below the concentrator 42. Next, the concentrator 42 of the laser beam irradiation means 4 continuously illuminates the pulsed laser beam, so that the chuck table 3, that is, the semiconductor wafer 10, is processed in a specific direction along the direction indicated by the arrow X1 in Fig. 11(a). Move the speed (laser light irradiation process). Next, as shown in FIG. 11(b), when the other end of the block 101 (the right end of FIG. 11(b)) reaches directly below the concentrator 42, the irradiation of the pulsed laser light is stopped, and at the same time, the clip is stopped. The head 3 is also the movement of the semiconductor wafer 10. In the laser light irradiation process, the light collecting point of the pulsed laser light is focused near the surface of the block 101.

The above-described laser beam irradiation process is performed to form the laser processing trench 120 shown in FIG. 12 in the block 101 of the semiconductor wafer 10. At this time, as shown in Fig. 12, even if the debris 130 is generated by the irradiation of the laser light, the debris 130 is blocked by the protective film 110 without adhering to the device 102, the bonding pad, and the like. Next, the above-described laser beam irradiation process is performed on all of the blocks 101 of the semiconductor wafer 10.

Further, the above-described laser beam irradiation process is carried out, for example, under the following processing conditions.

Source of laser light: YVO4 laser or YAG laser wavelength: 355nm repetition rate: 20kHz output: 3W pulse width: 0.1ns collection spot diameter: 5 μ m machining feed rate: 100mm/sec

After performing the above-described laser beam irradiation process along all the blocks 101 of the semiconductor wafer 10, the chuck stage 3 of the semiconductor wafer 10 is held, first returning to the position of attracting and holding the semiconductor wafer 10, thereby releasing the semiconductor The attraction of the wafer 10 is maintained. Then, the semiconductor wafer 10 is sucked and held by the holding means 171 of the second transfer means 17, and is transferred to the adsorption chuck 811a of the rotary table 811 constituting the cleaning means 8 by the rotation operation centered on the support means 172. Up, and is attracted to the adsorption chuck 811a. At this time, as shown in FIGS. 5 and 6, the washing water nozzle 841 and the gas nozzle 851 are positioned at a standby position above the rotary table 811.

After the processed semiconductor wafer 10 is held on the rotating table 811 of the cleaning means 8, a cleaning process is performed. In other words, the rotary table 811 is positioned at the work position shown in FIG. 7, and the electric motor 842 of the washing water supply means 86 is driven to position the discharge port of the nozzle portion 841a of the washing water supply nozzle 841 to be held in rotation. Above the center of the semiconductor wafer 10 on the stage 811. Next, the turntable 811 is continuously rotated at a rotation speed of, for example, 300 to 500 rpm, and the washing water composed of pure water and gas is discharged from the discharge port of the nozzle portion 841a. In other words, the nozzle portion 841a is composed of a so-called two-fluid nozzle, and supplies pure water of about 0.2 MPa, and supplies a gas of about 0.3 to 0.5 MPa, and discharges pure water to the processed surface of the semiconductor wafer 10 by the pressure of the gas. The surface 10a is washed. At this time, the electric motor 842 is driven so that the washing water sprayed from the discharge port of the nozzle portion 841a of the washing water supply nozzle 841 is in contact with the center position of the semiconductor wafer 10 held by the turntable 811 to the outer edge portion. Swing within the necessary angle range. As a result, since the protective film 110 covering the surface 10 of the semiconductor wafer 10 is formed of a water-soluble resin as described above, it is easy to rinse the protective film 110, and also removes the laser processing. Debris 130.

After the above washing process is completed, the drying process is carried out. That is, the washing water supply nozzle 841 is positioned at the standby position, and the discharge port of the gas supply means 85 for constituting the nozzle portion 851a of the gas nozzle 851 is positioned on the semiconductor wafer 10 held on the rotary table 811. Above the center. Next, the turntable 711 is rotated at a rotation speed of, for example, 2000 to 3000 rpm, and a gas discharge of about 15 seconds is performed from the discharge port of the nozzle portion 851a. At this time, the gas in which the gas nozzle 851 performs the discharge port of the nozzle portion 851a can be swung in contact with the necessary angular range of the position of the semiconductor wafer 10 from the center position to the outer edge portion of the turntable 811. As a result, the surface of the semiconductor wafer 10 is dried.

As described above, after the semiconductor wafer 10 after the processing is finished and dried, the rotation of the rotary stage 811 is stopped, and the gas nozzle 851 of the gas supply means 85 is positioned at the standby position. Next, the rotary table 811 is positioned at the workpiece loading/unloading position shown in FIG. 6, and the suction holding of the semiconductor wafer 10 held by the rotary table 811 is released. Next, the processed semiconductor wafer 10 on the rotary table 811 is carried out by the first transfer means 16 to the temporary placement stage 15 disposed in the temporary placement portion 15a. The processed semiconductor wafer 10 carried out to the temporary placement stage 15 is accommodated at a specific position of the cassette 13 by the workpiece carrying means 14.

In addition, the semiconductor wafer 10 subjected to the laser beam irradiation process described above is transferred to the cleaning means 8 to carry out the cleaning process and the drying process, and the workpiece loading/unloading means 14 is driven to process the next processing. The semiconductor wafer 10 is carried out from the cassette 13 to the temporary placement stage 15, and the semiconductor wafer 10 carried out to the temporary placement stage 15 is transferred to the protective film forming means 7 by the first transfer means 16. Next, the above-described protective film covering process is performed on the semiconductor wafer 10 that has been transferred to the next processing of the protective film forming means 7. In this way, the semiconductor wafer 10 subjected to the protective film covering process is transferred from the protective film forming means 7 to the chuck table 3 by the second transfer means 17, and the above-described laser light irradiation process is performed. Next, the semiconductor wafer 10 subjected to the laser beam irradiation process is transferred to the cleaning means 8 by the second transfer means 17, and the cleaning process and the drying process are performed. As described above, the embodiment shown in the figure includes the protective film forming means 7 and the cleaning means 8, and the semiconductor wafer 10 subjected to the laser beam irradiation process is subjected to a cleaning process and a drying process, and the next process can be performed. The semiconductor wafer 10 is transferred to the protective film forming means 7 and the protective film covering process is performed, so that the production efficiency can be improved.

2. . . Device housing

3. . . Chuck table

4. . . Laser light irradiation

5. . . Photography agency

6. . . Display means

7. . . Protective film forming means

8. . . Cleaning method

10. . . Semiconductor wafer

11. . . Ring frame

12. . . Protective tape

13. . . Card

14. . . The workpiece is moved out and moved in

15. . . Temporary placement desk

16. . . First transport means

17. . . Second transport means

41. . . Laser ray oscillation

42. . . Light collector

71. . . Rotary table mechanism

72. . . Washing water receiving means

74. . . Resin supply means

78. . . Washing water supply means

81. . . Rotary table mechanism

82. . . Washing water receiving means

85. . . Gas supply means

101. . . Block

102. . . Device

110. . . Protective film

711. . . Rotary table

712. . . electric motor

741. . . Resin liquid supply nozzle

811. . . Rotary table

812. . . electric motor

841. . . Washing water nozzle

851. . . Gas nozzle

Fig. 1 is a perspective view of a laser processing apparatus having the constitution of the present invention.

Fig. 2 is a partial cross-sectional perspective view showing a protective film forming means of the laser processing apparatus shown in Fig. 1.

Figure 3 is a rotating table of the protective film forming means shown in Fig. 2 positioned at the workpiece. An explanatory diagram of the state of moving out of position.

Fig. 4 is an explanatory view showing a state in which the rotary table of the protective film-shaped cleaning means shown in Fig. 2 is positioned at the work position.

Fig. 5 is a partial cross-sectional perspective view showing the cleaning means of the laser processing apparatus shown in Fig. 1.

Figure 6 is the rotating table of the cleaning means shown in Figure 2 positioned in the workpiece. An explanatory diagram of the state of moving out of position.

Fig. 7 is an explanatory view showing a state in which the rotary table of the cleaning means shown in Fig. 2 is positioned at the work position.

Fig. 8 is a perspective view showing a semiconductor wafer of a workpiece processed by the laser processing apparatus shown in Fig. 1.

Fig. 9 is an explanatory view showing a protective film covering process by the laser processing apparatus shown in Fig. 1.

Fig. 10 is an enlarged cross-sectional view showing an important part of a semiconductor wafer in which a protective film is formed to cover a workpiece of a protective film by a protective film.

Fig. 11 is an explanatory view showing a laser irradiation process using the laser processing apparatus shown in Fig. 1.

Fig. 12 is an enlarged cross-sectional view showing an important part of a semiconductor wafer on which a laser processed workpiece is processed by the laser beam irradiation process shown in Fig. 11.

2. . . Device housing

3. . . Chuck table

4. . . Laser light irradiation

5. . . Photography agency

6. . . Display means

7. . . Protective film forming means

8. . . Cleaning method

10. . . Semiconductor wafer

11. . . Ring frame

12. . . Protective tape

13. . . Card

13a. . . Cartridge loading section

14. . . The workpiece is moved out and moved in

15. . . Temporary placement desk

15a. . . Temporary resettlement

16. . . First transport means

17. . . Second transport means

31. . . Adsorption chuck support

32. . . Adsorption chuck

33. . . Fixture

41. . . Laser ray oscillation

42. . . Light collector

131. . . Card

161. . . Means of retention

162. . . Support means

171. . . Means of retention

172. . . Support means

Claims (1)

A laser processing apparatus comprising: a chuck table for holding a workpiece; and a laser light irradiation means for irradiating a workpiece held by the chuck table with a laser beam; a cassette mounting table for the workpiece; a loading/unloading means for carrying out the loading and unloading of the workpiece for the cassette placed on the cassette mounting table; and a temporary loading and unloading means for carrying out the loading and unloading means a temporary placement table for the workpiece, the laser processing apparatus characterized by: a protective film forming means for distributing a workpiece to be processed before being processed to the temporary placement table for transporting to the workpiece The first transport path of the chuck table covers the protective film on the processed surface of the workpiece before processing, and the cleaning means is disposed to transport the processed object held in the chuck table for transporting To the second transfer path of the temporary placement table, the protective film covering the processed surface of the processed object after processing is removed, and the first transfer means is processed before being processed to the temporary placement stage. Object transfer to the protection a film forming means for transferring the workpiece after the processing by the cleaning means to the temporary placement stage; and the second conveying means for performing the protective coating by the protective film forming means The workpiece before the processing is conveyed to the chuck table, and the processed object held by the chuck table is transferred to the cleaning means.