JP4748006B2 - Wafer processing method and apparatus - Google Patents

Description

  The present invention relates to a wafer processing method and apparatus, and more particularly, to a wafer processing method and apparatus for performing processing of a wafer by laser processing and removing melted deposits generated accompanying the processing.

  Conventionally, a process called dicing or scribing, which divides a wafer into individual parts and cuts it, was performed by rotating a blade containing diamond at high speed to mechanically groove the surface of the wafer, but chipping occurred. In particular, there are problems such as damage to the electrodes and operating area, and complicated equipment for processing while using a coolant such as water. Since it is very thin, such as from 10 μm to several hundreds of μm, it is extremely difficult to process efficiently at high speed without causing chipping by mechanical processing.

As a processing method for solving this problem, a method of processing by scanning a laser along a processing line of a wafer is known. For example, in a light emitting diode manufacturing method, a silicon carbide wafer is processed using a laser, and at that time, slag-like molten deposits are deposited on both sides of the processing groove, which adversely affects the divided parts. In order to solve the problem, a method of removing melted deposits by performing dry etching on a laser-processed wafer with a gas containing fluorine in a vacuum plasma processing apparatus is known (for example, Patent Documents). 1).
Japanese National Patent Publication No. 11-505666

  However, in processing using a laser, as shown in FIG. 14A, when the wafer 63 is irradiated with the laser 62 along the processing line 61b to process the groove 63, as shown in FIG. 14B. Further, when the melted deposit 64 adheres to both sides of the groove 63 on the surface of the wafer 61 and dry etching is performed using a fluorine-based gas so as to remove the melted deposit 64, FIG. As shown, the surface 61a of the wafer 61 is etched from the broken line to the solid line, and the edge 63a of the groove 63 is also etched. Further, the transistor region 61c formed on the wafer 61 has a problem of being damaged by processing. 61d is a bonding pad.

  Further, as described above, since it is divided into two processes, a laser processing process and a dry etching process, the manufacturing process including the moving process between them becomes complicated, and the equipment configuration becomes large because a vacuum plasma processing apparatus is used. There was a problem. There is also a problem that charge-up damage may occur during plasma processing. Furthermore, since a process using a mask or the like is performed in the dry etching process, there is a problem that a photomask forming process and a peeling process after the process are required.

  In addition, a method of removing the melted deposit by attaching a water-soluble film on the wafer surface prior to laser processing and washing the water-soluble film after laser processing is also considered, but to wash off the water-soluble film Therefore, there is a problem that the treatment process including the waste water treatment becomes complicated.

  The present invention solves the above-described conventional problems, and can efficiently process a wafer using a laser without fear of cracking, and adversely affects the melted deposits generated by the processing. An object of the present invention is to provide a wafer processing method and apparatus which can be efficiently removed without giving a film.

The wafer processing method of the present invention is a wafer processing method for processing a silicon-containing wafer by a laser, a specific gas atmosphere maintaining step for maintaining a specific gas atmosphere on the processed surface of the wafer to form a protective film on the surface, A laser processing step of processing a groove by irradiating a wafer with a laser in a gas atmosphere, and a laser processing along the groove for a molten deposit adhered on the protective film on both sides of the groove by the laser irradiation And an atmospheric pressure plasma irradiation step of removing the region where the molten deposits may adhere by irradiating the atmospheric pressure plasma .

According to the above configuration, processing is performed by irradiating the wafer with a laser while maintaining the processing surface of the wafer containing silicon such as SiO _x , SiN _x , and SiON in a specific gas atmosphere that forms a protective film on the surface. As a result, a protective film is formed on the wafer surface around the laser processing part at a high temperature by laser processing, and laser processing is performed in that state, so that molten deposits generated by the laser processing are formed. Because it adheres to the protective film, it is possible to remove the melted deposits easily and efficiently by applying various methods without adversely affecting the wafer, realizing high-quality wafer processing with high productivity. can do.

  The specific gas is preferably oxygen gas or nitrogen gas. An oxide film is formed when oxygen gas is used, and a nitride film is formed when nitrogen gas is used. Note that the atmosphere contains nitrogen gas and oxygen gas, but also contains moisture and impurities, so that only the unstable film is formed and functions as a protective film. Is not formed.

In addition, when a laser irradiation process is performed to irradiate an atmospheric pressure plasma containing a fluorine-based gas to a processing site by a laser, it is possible to efficiently remove the melted deposits adhering to the protective film accompanying the laser processing. In addition, since atmospheric pressure plasma can be generated with a simple and compact configuration, when performing laser processing with a wafer fixed with high positioning accuracy, atmospheric pressure plasma irradiation is performed with the wafer fixed as it is. The wafer can be processed with a simple processing process and equipment configuration. Note that atmospheric pressure plasma is generated by applying a high-frequency electric field to an inert gas, and as the inert gas, argon, helium, xenon, neon, nitrogen, or a mixed gas of one or more of these is used. The selected one is suitable, and the fluorine-containing gas contained therein is preferably a fluorocarbon gas such as SF ₆ , C ₂ F ₆ , and C ₄ F ₈ .

  The laser processing step and the plasma irradiation step may be performed after the laser processing step, or the laser processing step and the plasma irradiation step may be performed simultaneously. In the method of performing the plasma irradiation step after the laser processing step, the dispersion of the melt during laser processing does not spread so much, the amount of melted deposits is large, the speed of laser processing and the processing speed by irradiation with atmospheric pressure plasma are high. Suitable for different cases. Incidentally, the speed of laser processing depends on the material of the wafer and the processing depth, but is generally about 50 mm / s to 400 mm / s.

  On the other hand, the method of irradiating a laser into the atmospheric pressure plasma to be irradiated and performing the laser processing step and the plasma irradiation step at the same time is easy to disperse the melt widely during the laser processing, and because the amount of the melted deposit is small, the atmospheric pressure plasma In the case where the processing speed by irradiation can be adjusted to the speed of laser processing, it is preferable that the melt can be prevented from being scattered and processed at a high speed at a time.

  In addition, atmospheric pressure plasma containing a fluorine-based gas can be generated by applying a high-frequency electric field to an inert gas even if it is generated by applying a high-frequency electric field to a mixed gas of an inert gas and a fluorine-based gas. A gas containing a system gas may be mixed and generated.

Further, the wafer processing apparatus of the present invention is a wafer processing apparatus for processing a wafer containing silicon by a laser in a specific gas atmosphere for supplying a specific gas on the processed surface of the wafer and forming a protective film on the processed surface. A specific gas supply means for maintaining, a laser generating means for generating a laser, a laser irradiation means for processing a groove by irradiating a laser along a processing line of a wafer in a specific gas atmosphere, and an atmospheric pressure containing a fluorine-based gas Atmospheric pressure plasma generating means for generating and irradiating plasma; and molten deposits adhering to the protective film on both sides of the groove by laser irradiation by the laser irradiating means, and atmospheric pressure by the atmospheric pressure plasma generating means Bei and control means for controlling so that melting deposits along the plasma in the grooves is removed by irradiating a region that may be attached Those were.

  According to this configuration, the laser irradiation unit irradiates the laser along the processing line of the wafer while maintaining the specific gas atmosphere in which the protective film is formed on the processing surface of the wafer by the specific gas atmosphere maintaining unit. As a result, the melted deposits generated by the laser processing are deposited on the formed protective film, so that various methods can be applied to efficiently remove the melted deposits without adversely affecting the wafer. It is possible to realize high-quality wafer processing with high productivity.

  According to the wafer processing method and apparatus of the present invention, the wafer is processed by irradiating the laser with a laser while maintaining a specific gas atmosphere for forming a protective film on the surface of the wafer containing silicon. A protective film is formed on the wafer surface around the laser processing part at a high temperature by laser processing, and the laser processing is performed in that state, so that the molten deposit generated by the laser processing is formed. Since it adheres to the upper surface, it is possible to efficiently remove the melted adhering material without adversely affecting the wafer by applying various methods, and it is possible to realize high-quality and high-quality wafer processing.

  Hereinafter, embodiments of a wafer processing method and apparatus according to the present invention will be described with reference to FIGS.

(First embodiment)
First, a wafer processing method and apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

  First, basic steps of the wafer processing method of the present embodiment will be described with reference to FIG. First, as shown in FIG. 1A, the wafer 1 is loaded into a predetermined position and fixed with high positioning accuracy required for processing. The wafer 1 is a wafer containing silicon (Si) such as a silicon (Si) semiconductor or a silicon carbide (SiC) semiconductor. The thickness of the wafer 1 is about several tens to several hundreds μm when it is thin. As will be described later, a protective film 10 made of an oxide film or a nitride film is formed on the surface of the wafer 1 before the next laser processing, as will be described later.

  Next, as shown in FIG. 1B, by irradiating the laser 2 along the processing line of the wafer 1, the groove 3 along the processing line is formed on the wafer 1 as shown in FIG. Process. A specific example of the processing state of the grooves 3 on the wafer 1 is shown in FIG. The width of the groove 3 is generally several μm to 50 μm, and the depth is generally about 20 μm to 80 μm. In processing the groove 3, since it is not mechanically processed by contacting a blade that rotates at high speed, even if the wafer 1 is thin as described above, there is no risk of cracking and 50 mm / s. It can be processed at a high speed of ˜400 mm / s. On the other hand, along with the laser processing, the molten deposit 4 on both sides of the groove 3 on the surface of the wafer 1 adheres. In the present embodiment, the molten deposit 4 adheres on the protective film 10.

  Next, as shown in FIG. 1 (d), from the atmospheric pressure plasma generating means 6 to the region where the molten deposit 4 may adhere along with the laser processing along the processing line by the laser 2, A gas atmospheric pressure plasma 5 is irradiated. A specific example of the irradiation state of the atmospheric pressure plasma 5 on the wafer 1 is shown in FIG. The irradiation area (width) of the atmospheric pressure plasma 5 is around 0.1 mm to 1.0 mm, and the atmospheric pressure plasma 5 irradiated from the atmospheric pressure plasma generating means 6 is controlled to have a width dimension within the above range. It is possible to reliably avoid the possibility of damaging other regions, that is, the operation region part and the electrode part by the atmospheric pressure plasma 5. Furthermore, since at least the peripheral part of the laser processing site on the surface of the wafer 1 is covered with the protective film 10, damage of the region due to the atmospheric pressure plasma 5 can be effectively suppressed.

  As described above, after the groove 3 is processed by the laser 2, irradiation with the atmospheric pressure plasma 5 is performed, so that as shown in FIG. The kimono 4 is efficiently removed, and the opening edges 3a on both sides of the groove 3 are protected by the protective film 10, so that there is no shaving and high-quality processing of the groove 3 is realized. Furthermore, occurrence of charge-up damage due to plasma treatment can also be suppressed. FIG. 3 shows the shape of the wafer 1 after the wafer 1 is divided by the grooves 3 and diced into individual pieces 7 and separated into individual pieces 7 by the expanded sheet 8.

  Next, a wafer processing apparatus that performs the wafer processing method of the present embodiment will be described with reference to FIGS. In FIG. 4, a wafer processing apparatus 11 includes a wafer fixing means 12 for positioning and fixing the wafer 1 carried by a carry-in means (not shown) with high positional accuracy, a laser generating means 13 for generating a laser, Laser irradiation means 14 for irradiating laser 2 along the processing line of wafer 1, atmospheric pressure plasma generation means 6 for generating and irradiating atmospheric pressure plasma 5 containing fluorine-based gas, and atmospheric pressure plasma generation means 6 are tertiary. Three-dimensional movement means 15 for moving and positioning in the original direction, specific gas supply means 16 for supplying a specific gas toward the surface of the wafer 1 so as to form a specific gas atmosphere 18 on the surface of the wafer 1, and a specific gas The heating means 17 which heats is provided. The three-dimensional moving means 15 includes an X-axis table 15a that moves and positions in the horizontal X-axis direction, and a Y-axis table 15b that moves and positions in the Y-axis direction that is horizontal and perpendicular to the X-axis direction. And a Z-axis table 15c that moves and positions in the vertical direction. The X-axis table 15a generates the Y-axis table 15b, the Y-axis table 15b generates the Z-axis table 15c, and the Z-axis table 15c generates atmospheric pressure plasma. The means 6 are configured to move and position respectively.

  The specific gas supplied by the specific gas supply means 16 forms the protective film 10 on the surface of the wafer 1 as described above when the wafer 1 is heated to a high temperature when the wafer 1 is laser processed. Specifically, oxygen gas or nitrogen gas. The specific gas atmosphere 18 formed by the specific gas supply unit 16 is heated to 50 to 200 ° C. by the heating unit 17, and the surface of the wafer 1 is heated to this temperature, so that the stable protective film 10 is formed. It is surely formed in a short time. However, the protective film 10 is formed without the heating means 17.

  The wafer fixing means 12, the laser generating means 13, the laser irradiating means 14, the atmospheric pressure plasma generating means 6, the three-dimensional moving means 15, the specific gas supply means 16 and the heating means 17 are, as shown in FIG. In accordance with the operation command from the operation unit 22, the operation is controlled based on the operation program and various data stored in advance in the storage unit 21, and the operation state is displayed on the display unit 23.

  Specifically, as shown in FIG. 6, the control unit 20 activates the laser 2 in a state where the specific gas atmosphere 18 heated on the surface of the wafer 1 is formed by the specific gas supply unit 16 and the heating unit 17. The operation of the laser irradiation means 14 was controlled so as to process the groove 3 by scanning at a speed V1 (50 mm / s to 400 mm / s) along the processing line of the wafer 1, and then the atmospheric pressure plasma 5 was laser processed. The three-dimensional moving means 15 is configured to control the operation so as to scan the groove 3 at a speed V2 (<V1) to remove the molten deposit 4. When the difference between the moving speed V1 of the laser 2 and the moving speed V2 of the atmospheric pressure plasma 5 becomes excessive, the atmospheric pressure plasma generating means 6 has a length in the moving direction as shown by a virtual line in FIG. It is preferable to use a long-pressure atmospheric pressure plasma 5 that is irradiated in a wide range in the moving direction so as to ensure a long time for the atmospheric pressure plasma treatment.

  When the molten deposit 4 is removed by the atmospheric pressure plasma 5, the molten deposit 4 is adhered on the protective film 10. Therefore, the removal treatment can be performed easily and in a short time, and at least in the processing region. Since the periphery is covered with the protective film 10, there is no possibility that the wafer 1 is damaged by the atmospheric pressure plasma 5.

  Next, various configuration examples of the atmospheric pressure plasma generating means 6 will be described with reference to FIGS. In the example of FIG. 7A, a coiled antenna 32 is disposed around a cylindrical reaction vessel 31 made of an insulator, and a high frequency voltage of 1 MHz to 500 MHz is applied to the antenna 32 from a high frequency power source 33. By applying a high frequency electric field in the reaction vessel 31 and supplying a mixed gas 34 obtained by mixing a fluorine-based gas into an inert gas from one end 31 a of the reaction vessel 31, the atmospheric pressure plasma 5 is supplied from the other end 31 b of the reaction vessel 31. It is configured to blow out. In the example of FIG. 7B, an inner electrode 36 is disposed inside a reaction tube 35 made of a dielectric, and an outer electrode 37 is disposed on the outer periphery. A frequency of 10 KHz to 100 MHz from a high frequency power source is provided between the electrodes 36 and 37. The atmospheric pressure plasma 5 is generated in the reaction tube 35 and blown out from the blow-out port 38 by supplying a mixed gas into the reaction tube 35. Further, in the example of FIG. 7C, a pair of electrodes 40a and 40b are arranged on the outer periphery of a reaction tube 39 made of a rectangular dielectric material having a long and narrow cross-sectional shape, and a high frequency is provided between the electrodes 40a and 40b. A high frequency voltage having a frequency of 10 KHz to 100 MHz is applied from the power supply 41, and a mixed gas is supplied from one end 39a of the reaction tube 39 to blow out plasma from the other end 39b of the reaction tube 39.

  In the example of FIG. 8, as shown in FIG. 8A, the mixed gas 43 is supplied from one end 42 a of a reaction vessel 42 having a rectangular cross-sectional shape, and atmospheric pressure plasma 5 is supplied from the other end 42 b of the reaction vessel 42. As shown in FIG. 8 (b), a reaction space 44 in the reaction vessel 42 is sandwiched between the opposing long side walls of the reaction vessel 42 via dielectrics 45 on both sides. A pair of electrodes 46a and 46b are disposed, and a high frequency voltage having a frequency of 10 KHz to 100 MHz is applied from the high frequency power supply 47 between the electrodes 46a and 46b.

  In the example of FIG. 9, in the configuration example shown in FIG. 8, the inert gas 48 is supplied from one end 42 a of the reaction vessel 42, and the atmospheric pressure plasma 5 of the inert gas is blown out from the other end 42 b of the reaction vessel 42. In addition, a supply duct 49 for supplying a fluorine-based gas 50 or a mixed gas of an inert gas and a fluorine-based gas is disposed on one side of the other end 42 b of the reaction vessel 42. The supply duct 49 is substantially the same width as the reaction vessel 42 and has a blowout port 49a bent at the tip end located near the other end 42b of the reaction vessel 42 so as to follow the blown-out atmospheric pressure plasma 5. By supplying the fluorine-based gas 50 toward one side of the atmospheric pressure plasma 5 blowing out from the other end 42b of the reaction vessel 42 through the supply passage in the supply duct 49, the fluorine-based gas 50 is greatly increased. The atmospheric pressure plasma 5 containing the fluorine-based gas 50 is formed so as to overlap with the atmospheric pressure plasma 5.

  Further, in the example of FIG. 10, as shown in FIGS. 10A and 10B, a coiled antenna 52 is disposed around a cylindrical reaction vessel 51 made of a dielectric, and the antenna 52 has a high frequency power source. The lower end of the reaction vessel 51 is applied by applying a high-frequency electric field having a frequency of 1 MHz to 500 MHz from 53 to apply a high-frequency electric field in the reaction vessel 51 and supplying the first inert gas 54 from the upper end 51 a of the reaction vessel 51. The primary plasma 55 is blown out from 51b. Around the vicinity of the lower end 51b of the reaction vessel 51, a mixed gas vessel 56 forming an inverted prefix cone-like mixed gas region 57 whose diameter decreases downward is disposed, and a second inert gas and A plurality of gas supply ports 59 for supplying a mixed gas 58 of fluorine-based gas to the inside is provided. With this configuration, the secondary plasma 60 is generated when the primary plasma 55 collides with the mixed gas 58 in the mixed gas region 57, and the secondary plasma 60 (atmospheric pressure plasma 5) is generated from the lower end opening 57 a of the mixed gas region 57. It is configured to blow out.

  According to the present embodiment having the above-described configuration, the processing surface of the wafer 1 containing silicon is maintained in the specific gas atmosphere 18 and processed by irradiating the wafer 1 with the laser 2 at least at a high temperature by laser processing. The protective film 10 is reliably formed in a short time on the surface of the wafer around the laser processing portion, and the wafer 1 is irradiated with the laser 2 in this state to be efficiently processed mechanically using a high-speed rotating blade or the like. As in the case, it can be processed without fear of cracking, and the melted deposit 4 generated by the laser processing adheres to the formed protective film 10, so that fluorine-based gas is applied to the processing site. By irradiating the atmospheric pressure plasma 5 containing it, only the molten deposit 4 can be easily and efficiently removed, and the surface of the wafer 1 is covered with the protective film 10. Since the are, there is no possibility that the wafer 1 is subjected to damage at atmospheric pressure plasma 5, it is good processing quality with a high productivity.

  Further, the atmospheric pressure plasma generating means 6 for generating the atmospheric pressure plasma 5 has a remarkably simple and compact configuration as compared with the vacuum plasma processing apparatus, so that the wafer 1 is fixed by the wafer fixing means 12 with high positioning accuracy. After the laser processing in this state, it becomes possible to irradiate the atmospheric pressure plasma 5 as it is, and the wafer 1 can be processed efficiently with a simple processing process and equipment configuration. Productivity can be realized.

  Further, after processing the groove 3 by irradiating the wafer 1 with the laser 2, the plasma generating means 6 is moved along the groove 3 to irradiate the atmospheric pressure plasma 5, and both sides of the groove 3 on the surface of the wafer 1. In the method of this embodiment in which the molten deposit 4 is removed, the scattering of the melt during laser processing does not spread so much, and the amount of the molten deposit 4 is large, which is large with respect to the laser processing speed V1. This is effective when the processing speed V2 by the atmospheric pressure plasma irradiation is low.

(Second Embodiment)
Next, a second embodiment of the wafer processing method and apparatus of the present invention will be described with reference to FIGS. In the following description of the embodiments, the same constituent elements as those of the preceding embodiments are denoted by the same reference numerals, description thereof is omitted, and only differences will be mainly described.

  In the first embodiment, the example in which the melted deposit 4 is removed by irradiating the atmospheric pressure plasma 5 after processing with the laser 2 is shown, but in this embodiment, as shown in FIG. The laser 2 is irradiated to the irradiation area of the atmospheric pressure plasma 5 in accordance with the movement of the irradiation area of the atmospheric pressure plasma 5 by the atmospheric pressure plasma generating means 6 so that the processing step by the laser 2 and the irradiation process of the atmospheric pressure plasma 5 are performed simultaneously. The laser irradiation means 14 and the three-dimensional movement means 15 are controlled in synchronization. That is, as shown in FIG. 12, the control unit 20 controls the operation of the laser irradiation unit 14 so as to scan the laser 2 along the processing line of the wafer 1 at a speed V1 (about 50 mm / s to 100 mm / s). At the same time, the three-dimensional moving means 15 is configured to control the operation so that the atmospheric pressure plasma generating means 6 is scanned synchronously at the same speed V1 (about 50 mm / s to 100 mm / s).

  According to this embodiment, the laser processing step and the plasma irradiation step are performed simultaneously by irradiating the laser 2 in the atmospheric pressure plasma 5 to be irradiated, so that the melt is easily scattered widely at the time of laser processing. Since the amount is small, when the processing speed by irradiation with the atmospheric pressure plasma 5 can be matched with the processing speed by the laser 2, it is preferable because the melt can be prevented from being scattered and processed at a high speed at a time.

(Third embodiment)
Next, a third embodiment of the wafer processing method and apparatus of the present invention will be described with reference to FIG.

  In the first embodiment, as the means for heating the surface of the wafer 1 to a predetermined temperature, the specific gas supplied toward the surface of the wafer 1 is heated by the heating means 17 so that the specific gas atmosphere 18 side Although an example of heating is shown, in this embodiment, as shown in FIG. 13, a heater 19 is built in the wafer fixing means 12 for positioning and fixing the wafer 1, and the entire wafer 1 is 50 to 50 by the heater 19. Heating is performed to a predetermined temperature of 200 ° C. However, the protective film 10 can be formed on the surface of the wafer 1 without heating the wafer 1 to a predetermined temperature by the heater 19.

  In the description of the above embodiment, only the method of removing by irradiating the atmospheric pressure plasma 5 is exemplified as a method of removing the melted deposit 4 adhering to both sides of the groove 3 with laser processing. In the present invention, the molten deposit 4 adheres on the protective film 10 and can be removed relatively easily without damaging the wafer 1, so that it can be removed by other suitable means such as dry etching using a vacuum plasma processing apparatus. You may make it remove.

  According to the wafer processing method and apparatus of the present invention, by performing laser processing in a state where a protective film is formed at least on the surface of the wafer around the laser processing portion, it is efficient without causing a crack in the wafer by laser processing. In addition, the melted deposits generated by the laser processing adhere to the formed protective film, so that various methods can be applied to efficiently melt the wafer without adversely affecting the wafer. Since deposits can be removed, and high-quality and high-quality wafer processing can be realized, it can be suitably used for laser processing of various wafers containing silicon.

Process explanatory drawing of the wafer processing method of the 1st Embodiment of this invention. The top view which shows the laser processing state and atmospheric pressure plasma irradiation state with respect to the wafer in the same embodiment. The perspective view of the processed wafer in the embodiment. The block diagram of the wafer processing apparatus of the embodiment. The block diagram of the control part of the wafer processing apparatus of the embodiment. The state explanatory view at the time of processing of the embodiment. The various structural examples of the atmospheric pressure plasma generator in the same embodiment are shown, (a) is a perspective view of the first structural example, (b) is a cross-sectional view of the second structural example, (c) is the third configuration. FIG. The other example of a structure of the atmospheric pressure plasma generator in the embodiment is shown, (a) is a perspective view, (b) is a perspective view showing the basic structure. The perspective view which shows another structural example of the atmospheric pressure plasma generator in the same embodiment. The further another structural example of the atmospheric pressure plasma generator in the embodiment is shown, (a) is sectional drawing, (b) is a perspective view. The block diagram of the wafer processing apparatus of the 2nd Embodiment of this invention. The state explanatory view at the time of processing of the embodiment. State explanatory drawing at the time of the process by the wafer processing apparatus of the 3rd Embodiment of this invention. Explanatory drawing of the wafer processing process of a prior art example, and its problem.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer 2 Laser 3 Groove 4 Molten deposit 5 Atmospheric pressure plasma 6 Atmospheric pressure plasma generation means 10 Protective film 11 Wafer processing apparatus 12 Wafer fixing means 13 Laser generation means 14 Laser irradiation means 15 Three-dimensional movement means 16 Specific gas supply means 18 Specific gas atmosphere 20 Control means

Claims (8)

In a wafer processing method for processing a wafer containing silicon by a laser, a specific gas atmosphere maintaining step for maintaining a protective film on the processed surface of the wafer in a specific gas atmosphere, and a laser on the wafer in the specific gas atmosphere. Laser processing step for processing grooves by irradiation, and melted deposits adhered to the protective film on both sides of the grooves by the laser irradiation, and melted deposits adhere along the grooves along with the laser processing. And an atmospheric pressure plasma irradiation step of removing the region that is likely to be irradiated by irradiating with atmospheric pressure plasma .   2. The wafer processing method according to claim 1, wherein the specific gas is oxygen gas or nitrogen gas. The atmospheric pressure plasma, a wafer processing method according to claim 1 or 2, wherein the atmospheric pressure plasma comprising a fluorine-based gas. After the laser processing step, the wafer processing method according to any one of claims 1 to 3, characterized in that said atmospheric pressure plasma irradiation step. The wafer processing method according to claim 1, wherein the laser processing step and the atmospheric pressure plasma irradiation step are performed simultaneously by irradiating a laser into the atmospheric pressure plasma to be irradiated.   6. The wafer processing method according to claim 3, wherein the atmospheric pressure plasma containing a fluorine-based gas is generated by applying a high-frequency electric field to a mixed gas of an inert gas and a fluorine-based gas.   6. The atmospheric pressure plasma containing a fluorine-based gas is generated by mixing a gas containing a fluorine-based gas with a plasma generated by applying a high-frequency electric field to an inert gas. The wafer processing method as described in 2. above. In a wafer processing apparatus for processing a wafer containing silicon by a laser, a specific gas supply means for supplying a specific gas on the processing surface of the wafer and maintaining a specific gas atmosphere for forming a protective film on the processing surface, and a laser Laser generating means for generating, laser irradiation means for irradiating a laser along a processing line of a wafer in a specific gas atmosphere to process grooves, and atmospheric pressure plasma for generating and irradiating atmospheric pressure plasma containing a fluorine-based gas Generating means;
The molten deposit adhered on the protective film on both sides of the groove by the laser irradiation by the laser irradiation means, and the atmospheric deposit by the atmospheric pressure plasma generating means can adhere the molten deposit along the groove. A wafer processing apparatus comprising: a control unit that controls to remove the region by irradiating a characteristic region .

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