How the chip is manufactured

Abstract

To provide a manufacturing method of a chip, enabling suppression of defect in dividing a wafer in which an insulating film and a thin film consisting of silicon are laminated on a substrate, into chips.SOLUTION: A manufacturing method of a chip includes: a holding step 101 of holding a front face side of a wafer by a holding table; a heating step 102 of positioning a condensing point of a laser beam of a wavelength with permeability for the wafer in the vicinity of a front face of the wafer, irradiating the wafer with the laser beam, heating and embrittling the insulating film and the thin film along a predetermined dividing line which is set in the wafer; a modified layer forming step 103 of positioning the condensing point of the laser beam inside the wafer, irradiating the wafer from a rear face side, and forming a modified layer along the predetermined dividing line which is set in the wafer; and a dividing step 104 of applying an external force to the wafer and dividing the wafer into chips with the modified layer which is formed inside the predetermined dividing line, defined as a starting point.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a chip. [Background technology]

[0002] A known method for manufacturing semiconductor devices involves irradiating a wafer on which devices are formed with a laser beam having a wavelength that is transparent to the wafer by positioning a focal point inside the wafer and forming a modified layer that serves as the starting point for splitting along the intended split lines (see, for example, Patent Document 1).

[0003] Incidentally, in recent years, devices called SOI (Silicon on Insulator), which have a structure in which an insulating film is embedded under a thin film made of silicon, have begun to be developed and manufactured (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3408805 [Patent Document 2] JP 2000-30993 A Summary of the Invention [Problem to be solved by the invention]

[0005] When making a chip from a semiconductor device incorporating an insulating film like this, if the method shown in Patent Document 1 is used, the laser beam is blocked by the insulating film and processing is not performed on the thin film portion, resulting in poor separation of the chip.

[0006] The present invention has been made in consideration of such problems, and its object is to provide a method for manufacturing chips that can suppress defects in dividing a wafer having an insulating film and a thin film made of silicon stacked on a substrate into chips. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the chip manufacturing method of the present invention is a chip manufacturing method for manufacturing chips by dividing a wafer having, on its front surface side, a substrate made of silicon, an insulating film formed on the substrate, and a thin film formed on the insulating film and made of silicon, the method comprising: a holding step for holding the front surface side of the wafer with a holding table; and a heating step for irradiating the wafer with a laser beam having a wavelength that is transparent to the wafer, with the focal point positioned near the front surface of the wafer, and heating and embrittling the insulating film and thin film along a planned division line set on the wafer, the heating step including: After the heating step, A laser beam having a wavelength that is transparent to the wafer is focused on the wafer. The substrate a modified layer forming step of irradiating the wafer with light from a position inside the wafer to form a modified layer along a division line set on the wafer; and a dividing step of dividing the wafer into individual chips by applying an external force to the wafer and dividing the wafer into individual chips from the modified layer formed inside the division line. In the heating step and the modified layer forming step, the laser beam is irradiated onto the back side of the wafer. The present invention is characterized by the above.

[0008] In the method for manufacturing a chip, in the heating step, the energy of the laser beam may be set so as not to exceed the processing threshold of the insulating film and the thin film.

[0009] In the method for manufacturing a chip, the wafer may further have a passivation film on the thin film, and the heating step may heat the insulating film and the thin film as well as the passivation film. Effect of the Invention

[0010] The chip manufacturing method of the present invention has an effect of suppressing defects in dividing a wafer, in which an insulating film and a thin film made of silicon are laminated on a substrate, into chips. [Brief description of the drawings]

[0011] [Figure 1]FIG. 1 is a perspective view showing an example of a wafer to be processed in the chip manufacturing method according to the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of a portion of the wafer shown in FIG. [Diagram 3] FIG. 3 is a flowchart showing the flow of the method for producing the chip according to the first embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view, partly in section, showing the holding step of the method for producing the chip shown in FIG. [Diagram 5] FIG. 5 is a schematic cross-sectional view, partly in section, showing a heating step in the method for producing the chip shown in FIG. [Figure 6] FIG. 6 is a schematic cross-sectional view, partially in cross section, showing a modified layer forming step in the method for producing the chip shown in FIG. [Figure 7] FIG. 7 is a side view, partially in section, showing a schematic state in which the expansion device holds the wafer in the dividing step of the chip manufacturing method shown in FIG. [Figure 8] FIG. 8 is a side view, partially in section, showing a schematic diagram of a state in which the expanding device divides the wafer into individual chips in the dividing step of the chip manufacturing method shown in FIG. [Figure 9] FIG. 9 is a plan view showing a schematic shape of a laser beam spot in a heating step of a chip manufacturing method according to a modified example of the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The form (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiment. Furthermore, the components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the configurations described below can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the configurations can be made without departing from the gist of the present invention.

[0013] [Embodiment 1] A method for manufacturing a chip according to a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing an example of a wafer to be processed by the method for manufacturing a chip according to the first embodiment. Fig. 2 is a cross-sectional view of a part of the wafer shown in Fig. 1. Fig. 3 is a flow chart showing the flow of the method for manufacturing a chip according to the first embodiment.

[0014] The chip manufacturing method according to the first embodiment is a method for processing a wafer 1 shown in Fig. 1. The wafer 1 to be processed in the chip manufacturing method according to the first embodiment is a disk-shaped semiconductor wafer having a silicon (Si) substrate 2, an optical device wafer, or the like.

[0015] 1, the wafer 1 has a surface 4 divided by a plurality of intersecting dividing lines 3, and devices 5 are formed in each of the regions of the surface 4. The devices 5 are, for example, integrated circuits such as ICs (Integrated Circuits) or LSIs (Large Scale Integrations), image sensors such as CCDs (Charge Coupled Devices) and CMOSs ​​(Complementary Metal Oxide Semiconductors), or MEMS (Micro Electro Mechanical Systems).

[0016] As shown in Figs. 1 and 2, the wafer 1 has a substrate 2 made of silicon, an insulating film 6 made of an insulator (e.g., SiO2) formed on the substrate 2, and a thin Si film 7, which is a thin film formed on the insulating film 6 and made of silicon, on the surface 4 side. In the first embodiment, the wafer 1 is an SOI (Silicon on Insulator) wafer having the insulating film 6 and the thin Si film 7 formed on the insulating film 6 on the surface side of the substrate 2, and the device 5 is a MEMS. In the first embodiment, the wafer 1 further has a passivation film 8 on the thin Si film 7. In the present invention, the insulating film 6, the thin Si film 7, and the passivation film 8 are made of materials that become embrittled when heated.

[0017] In the first embodiment, the wafer 1 is cut along the dividing lines 3 and divided into a plurality of chips 10. Each chip 10 is composed of the substrate 2, the insulating film 6, the Si thin film 7, and a part of the passivation film 8.

[0018] The chip manufacturing method according to the first embodiment is a method for manufacturing chips 10 by dividing the wafer 1 having the above-described configuration along a plurality of planned division lines 3 that define devices 5. The chip manufacturing method according to the first embodiment includes a holding step 101, a heating step 102, a modified layer forming step 103, and a dividing step 104, as shown in FIG.

[0019] (holding step) Fig. 4 is a schematic cross-sectional view, partially in cross section, showing a holding step in the method for producing the chip shown in Fig. 3. The holding step 101 is a step in which the front surface 4 side of the wafer 1 is held by a holding table 21.

[0020] In the holding step 101 in the first embodiment, an adhesive layer of a tape 11 having a diameter larger than the outer diameter of the wafer 1 is attached to the rear surface 9 behind the front surface 4 of the wafer 1, and the outer edge of the adhesive layer of the tape 11 is attached to an annular frame 12 having an inner diameter larger than the outer diameter of the wafer 1, so that the wafer 1 is supported by the tape 11 within an inner opening 13 of the annular frame 12. The tape 11 includes a base layer made of a flexible and non-adhesive synthetic resin, and an adhesive layer made of a flexible and adhesive synthetic resin laminated on the base layer.

[0021] 4, in the holding step 101, the laser processing device 20 sucks and holds the front surface 4 side of the wafer 1 placed on the holding surface 22 of the holding table 21 to the holding surface 22 of the holding table 21, and clamps the annular frame 12 with a plurality of clamps 23 provided on the outer periphery of the holding table 21. In the embodiment 1, a porous sheet made of a porous material (not shown) is disposed between the holding table 21 and the front surface 4 of the wafer 1 to protect the front surface 4 of the wafer 1.

[0022] (Heating step) Fig. 5 is a schematic partial cross-sectional view of the heating step of the method for producing the chip shown in Fig. 3. The heating step 102 is a step performed after the holding step 101, in which a focal point 26 of a laser beam 25 having a wavelength that is transparent to the wafer 1 is positioned near the front surface 4 of the wafer 1 and irradiated from the back surface 9 side of the wafer 1, thereby heating and embrittling the insulating film 6 and the Si thin film 7 along the planned dividing lines 3 set on the wafer 1.

[0023] In the present invention, the vicinity of the surface 4 of the wafer 1 where the focal point 26 of the laser beam 25 is located preferably indicates the inside of any of the insulating film 6, the Si thin film 7, and the passivation film 8. In addition, the vicinity of the surface 4 of the wafer 1 where the focal point 26 of the laser beam 25 is located may be a surface layer of the substrate 2 closer to the insulating film 6. In short, the vicinity of the surface 4 of the wafer 1 where the focal point 26 of the laser beam 25 is located indicates the position of the focal point 26 where the insulating film 6, the Si thin film 7, and the passivation film 8 can be heated by the laser beam 25 irradiated to the wafer 1 in the heating step 102 with a lower output than the modified layer forming step 103, thereby making them more embrittled than before heating.

[0024] In the embodiment 1, in the heating step 102, the laser processing device 20 sets a focal point 26 of a laser beam 25 having a wavelength that is transparent to the wafer 1 irradiated by the laser beam irradiation unit 24 inside any of the insulating film 6, the Si thin film 7, and the passivation film 8. In the embodiment 1, in the heating step 102, the laser processing device 20 irradiates the wafer 1 with a pulsed laser beam 25 along the planned division lines 3 from the back surface 9 side while relatively moving the holding table 21 and the laser beam irradiation unit 24 along the planned division lines 3, as shown in FIG.

[0025] In the first embodiment, in the heating step 102, the output, which is the energy of the laser beam 25, is set to a value that does not exceed the processing threshold of the insulating film 6 and the Si thin film 7. The value that does not exceed the processing threshold is a value at which the modified layer 15 described later is not formed inside the insulating film 6, the Si thin film 7, and the substrate 2 by the irradiation of the laser beam 25 and which embrittles them, and is, for example, a value lower than the output of the laser beam 25 in the modified layer forming step 103.

[0026] Thus, in embodiment 1, in the heating step 102, the laser processing apparatus 20 irradiates the wafer 1 from the back surface 9 side along the planned dividing line 3 with a pulsed laser beam 25 while moving the holding table 21 and the laser beam irradiation unit 24 relatively along the planned dividing line 3, thereby heating the insulating film 6 and the Si thin film 7, and also heating the passivation film 8, thereby embrittling them along the planned dividing line 3.

[0027] In the first embodiment, in the heating step 102, the laser processing device 20 irradiates the wafer 1 from the back surface 9 with a pulsed laser beam 25 while moving the holding table 21 and the laser beam irradiation unit 24 relatively along each of the planned dividing lines 3 twice. That is, in the first embodiment, in the heating step 102, the laser processing device 20 irradiates each of the planned dividing lines 3 of the wafer 1 from the back surface 9 with a pulsed laser beam 25 twice. In the present invention, in the heating step 102, it is sufficient that the laser processing device 20 irradiates the wafer 1 from the back surface 9 with a pulsed laser beam 25 while moving the holding table 21 and the laser beam irradiation unit 24 relatively along each of the planned dividing lines 3 at least once.

[0028] In addition, in the first embodiment, in the heating step 102, the focal point 26 of the laser beam 25 is set inside any one of the insulating film 6, the Si thin film 7, and the passivation film 8, but in the present invention, the position of the focal point 26 may be any position near the surface 4 of the wafer 1 described above.

[0029] (Modified layer formation step) Fig. 6 is a schematic partial cross-sectional view showing the modified layer forming step of the method for manufacturing the chip shown in Fig. 3. The modified layer forming step 103 is a step in which a focal point 26 of a laser beam 25 having a wavelength that is transparent to the wafer 1 is positioned inside the substrate 2 of the wafer 1 and irradiated from the back surface 9 side of the wafer 1 to form a modified layer 15 along the planned dividing lines 3 set on the wafer 1.

[0030] The modified layer 15 means a region in which the density, refractive index, mechanical strength, and other physical properties are different from those of the surrounding area, and examples of such regions include a melting process region, a crack region, a dielectric breakdown region, a refractive index change region, and a region in which these regions are mixed, etc. The modified layer 15 also has a lower mechanical strength, etc. than other parts of the substrate 2 of the wafer 1.

[0031] In the first embodiment, in the modified layer forming step 103, the laser processing device 20 sets a focal point 26 of a laser beam 25 having a wavelength that is transparent to the wafer 1 inside the substrate 2. In the first embodiment, in the modified layer forming step 103, the laser processing device 20 irradiates the wafer 1 with a pulsed laser beam 25 along the intended dividing lines 3 from the back surface 9 side while relatively moving the holding table 21 and the laser beam irradiation unit 24 along the intended dividing lines 3, as shown in FIG.

[0032] In the modified layer formation step 103, a laser processing device 20 irradiates a laser beam 25 having a wavelength that is transparent to the wafer 1, thereby forming a modified layer 15 inside the substrate 2 of the wafer 1 along the intended division line 3.

[0033] In the modified layer forming step 103 in the embodiment 1, the laser processing device 20 irradiates the wafer 1 from the back surface 9 side with a pulsed laser beam 25 while relatively moving the holding table 21 and the laser beam irradiation unit 24 multiple times along each of the planned dividing lines 3. That is, in the heating step 102 in the embodiment 1, the laser processing device 20 irradiates each of the planned dividing lines 3 of the wafer 1 from the back surface 9 side with a pulsed laser beam 25 multiple times.

[0034] In the present invention, in the modified layer forming step 103, the laser processing device 20 may change the position of the focal point 26 in the thickness direction or may change the output when irradiating each of the planned dividing lines 3 of the wafer 1 with the pulsed laser beam 25 from the back surface 9 side multiple times. Also, in the present invention, in the modified layer forming step 103, the laser processing device 20 sets the output of the laser beam 25 to be higher than the output of the laser beam 25 in the heating step 102 at least once when irradiating each of the planned dividing lines 3 of the wafer 1 with the pulsed laser beam 25 from the back surface 9 side multiple times.

[0035] (split step) Fig. 7 is a schematic partial cross-sectional side view showing a state in which the expansion device holds a wafer in the dividing step of the chip manufacturing method shown in Fig. 3. Fig. 8 is a schematic partial cross-sectional side view showing a state in which the expansion device divides the wafer into individual chips in the dividing step of the chip manufacturing method shown in Fig. 3.

[0036] The dividing step 104 is a step in which an external force is applied to the wafer 1 to divide it into individual chips 10 starting from the modified layer 15 formed inside the dividing lines 3. In the dividing step 104, as shown in Fig. 7, the expansion device 50 holds the wafer 1 between a frame mounting plate 51 and a frame pressing plate 52 by sandwiching the outer edge of the tape 11 and the annular frame 12 that supports the wafer 1 inside the opening 13, and also brings a roller member 54 provided at the upper end of an expansion drum 53 into contact with the tape 11.

[0037] Thus, in the division step 104, as shown in Fig. 7, the expansion device 50 holds the annular frame 12 supporting the wafer 1 and the like with the frame mounting plate 51 and the frame pressing plate 52, with the tape 11 in a flat state from the outer edge to the center. In the division step 104, the expansion device 50 moves the annular frame 12 and the wafer 1 relatively along a direction intersecting (orthogonal in the first embodiment) the surface of the wafer 1. In the first embodiment, in the division step 104, the expansion device 50 raises the expansion drum 53 as shown in Fig. 8, and moves the annular frame 12 and the wafer 1 relatively along a direction intersecting (orthogonal in the first embodiment) the surface of the wafer 1.

[0038] Then, the roller members 54 press the tape 11 between the outer edge of the wafer 1 and the inner edge of the annular frame 12 from below to above, and the tape 11 is expanded in the planar direction. As a result of the expansion of the tape 11, a tensile force acts radially on the tape 11. When a tensile force acts radially on the tape 11 attached to the rear surface 9 of the wafer 1, the modified layer 15 is formed along the division lines 3 of the wafer 1, and the insulating film 6, the Si thin film 7, and the passivation film 8 are embrittled along the division lines 3, so that the substrate 2, the insulating film 6, the Si thin film 7, and the passivation film 8 are divided along the division lines 3 using the modified layer 15 as a base point.

[0039] Thus, in the dividing step 104, the wafer 1 is divided into individual chips 10. The individually divided chips 10 are picked up from the tape 11.

[0040] In the chip manufacturing method according to the first embodiment described above, the focal point 26 is set near the surface 4 of the wafer 1, and the laser beam 25 is irradiated along the division line 3 to heat and embrittle the insulating film 6, the Si thin film, and the passivation film 8, and then a modified layer 15 is formed inside the substrate 2, and the wafer 1 is divided into individual chips 10. For this reason, the manufacturing method of the chip 10 embrittles the insulating film 6, the Si thin film 7, and the passivation film 8, which have been the cause of division failure due to heating, and therefore makes it easier to divide them. As a result, the chip manufacturing method according to the first embodiment has the effect of suppressing division failure into the chips 10 of the wafer 1, in which the insulating film 6, the Si thin film made of silicon, and the passivation film 8 are stacked on the substrate 2.

[0041] [Modifications] A method for producing a chip according to a modified example of the first embodiment of the present invention will be described with reference to the drawings. Fig. 9 is a plan view showing a schematic shape of a laser beam spot in a heating step of the method for producing a chip according to a modified example of the first embodiment. In Fig. 9, the same parts as those in the first embodiment are denoted by the same reference numerals and will not be described.

[0042] The method for manufacturing a chip according to the modified example is the same as that of the first embodiment, except that the shape of the spot 251 of the laser beam 25 in the heating step 102 is formed into a shape that can restrict the laser beam 25 from being irradiated onto the device 5, as shown in Fig. 9. Note that in Fig. 9, the shape of the spot 251 of the laser beam 25 is an ellipse extending along the intended division lines 3, but in the present invention, the shape is not limited to the shape shown in Fig. 9 as long as the laser beam 25 is not irradiated onto the device 5. Note that the shape of the spot 251 of the laser beam 25 is formed, for example, as shown in Fig. 9, using a known mask or a spatial light modulator (LCOS; Liquid Crystal On Silicon).

[0043] In the chip manufacturing method of the modified example, a focal point 26 is set near the surface 4 of the wafer 1 and a laser beam 25 is irradiated along the intended division line 3 to heat and embrittle the insulating film 6, the Si thin film and the passivation film 8, making them easier to divide. As in the first embodiment, this has the effect of suppressing poor division of a wafer 1 having an insulating film 6, a Si thin film 7 made of silicon, and a passivation film 8 stacked on a substrate 2 into chips 10.

[0044] Furthermore, in the case of a device having a through-hole from the front surface 4 to the back surface 9, in heating step 102, the energy density of laser beam 25 incident from back surface 9 is affected by the through-hole and reaches the vicinity of front surface 4, which changes from the case where there is no through-hole. Therefore, in the chip manufacturing method according to the modified example, the shape of spot 251 of laser beam 25 in heating step 102 is formed into a shape that can restrict laser beam 25 from being irradiated onto device 5, so that processing can be performed without laser beam 25 being affected by the structure of device 5.

[0045] In the present invention, the shape of the spot 251 of the laser beam 25 in the modified layer forming step 103 may be formed into a shape that can restrict the laser beam 25 from being irradiated onto the device 5, as shown in FIG.

[0046] Next, the inventors of the present invention confirmed the effect of the chip manufacturing method according to the above-mentioned embodiment 1 by dividing the same wafer 1 into individual chips 10 and measuring the ratio of the individual chips 10 (hereinafter referred to as the division ratio) in each of the comparative example and the present invention. The results are shown in Table 1.

[0047] [Table 1]

[0048] In the comparative example in Table 1, the heating step 102 of the chip manufacturing method of embodiment 1 was not performed, but the holding step 101, the modified layer formation step 103 and the division step 104 were performed in sequence to divide the wafer 1 into individual chips 10.

[0049] For the present invention products in Table 1, the chip manufacturing method according to the first embodiment was carried out, and the wafer 1 was divided into individual chips 10.

[0050] In the confirmation shown in Table 1, the repetition frequency of the laser beam 25 in the modified layer formation step 103 of the comparative example and the heating step 102 and modified layer formation step 103 of the product of the present invention, and the relative movement speed of the laser beam irradiation unit 24 and the holding table 21 were the same.

[0051] In addition, in the heating step 102 of the present invention, the defocus position was set to -0.093 mm, the output of the laser beam 25 was set to 0.2 W, and the laser beam 25 was irradiated onto the wafer 1 from the back surface 9 side along each planned division line 3 twice (hereinafter referred to as a pass).

[0052] In addition, in the product of the present invention and the comparative example, in the modified layer formation step 103, a laser beam 25 is irradiated onto the wafer 1 from the back surface 9 side along each planned division line 3 in five passes, with the defocus position of the first pass being -0.09 mm and the output of the laser beam 25 being 0.4 W, the defocus position of the second pass being -0.075 mm and the output of the laser beam 25 being 2.0 W, the defocus position of the third pass being -0.014 mm and the output of the laser beam 25 being 0.3 W, the defocus position of the fourth pass being -0.04 mm and the output of the laser beam 25 being 1.6 W, and the defocus position of the fifth pass being -0.055 mm and the output of the laser beam 25 being 2.0 W.

[0053] According to Table 1, in the comparative example, only 60% of the chips 10 could be singulated. In contrast to this comparative example, in the product of the present invention, 100% of the chips 10 could be singulated.

[0054] Therefore, according to Table 1, in the heating step 102, a focal point 26 of a laser beam 25 having a wavelength that is transparent to the wafer 1 is positioned near the front surface 4 of the wafer 1 and irradiated from the back surface 9 side of the wafer 1, thereby heating and embrittling the insulating film 6, Si thin film and passivation film 8 along the planned division lines 3 set on the wafer 1, and it has become clear that this makes it possible to suppress failure to divide the wafer 1, which has the insulating film 6, the Si thin film 7 made of silicon, and the passivation film 8 stacked on the substrate 2, into chips 10.

[0055] The present invention is not limited to the above embodiment. In other words, various modifications can be made without departing from the gist of the present invention. For example, in the present invention, the wafer 1 to be divided into chips 10 does not need to have a passivation film 8 formed on the Si thin film 7.

[0056] In the present invention, the wafer 1 to be divided into the chips 10 is not limited to an SOI wafer. In the present invention, the wafer 1 to be divided into the chips 10 may be a wafer in which the substrate 2 and the Si thin film 7 are bonded and fixed with an adhesive that is the insulating film 6. [Explanation of symbols]

[0057] 1 wafer 2. Board 3. Planned division line 4 surface 6. Insulating film 7 Si thin film (thin film) 8 Passivation film 9 Back side 10 Chips 15 Modification layer 21 Holding table 25 Laser Beam 26 Focus point 101 Retention Step 102 Heating Step 103 Modified layer formation step 104 division steps

Claims

1. A method for manufacturing chips by dividing a wafer having a surface side including a substrate made of silicon, an insulating film formed on the substrate, and a thin film formed on the insulating film and made of silicon, comprising: a holding step of holding the front surface side of the wafer on a holding table; a heating step in which, after the holding step, a focal point of a laser beam having a wavelength that is transparent to the wafer is positioned near the surface of the wafer and irradiated to heat and embrittle the insulating film and the thin film along a planned dividing line set on the wafer; a modified layer forming step of irradiating a laser beam having a wavelength that is transparent to the wafer with a focal point positioned inside the substrate of the wafer to form a modified layer along a planned dividing line set on the wafer after the heating step; a dividing step of dividing the wafer into individual chips starting from modified layers formed inside the dividing lines by applying an external force to the wafer; having In the heating step and the modified layer forming step, the back side of the wafer is irradiated with the laser beam.

2. In the heating step, 2. The method for manufacturing a chip according to claim 1, wherein the energy of the laser beam is set so as not to exceed the processing threshold of the insulating film and the thin film.

3. The wafer further has a passivation film on the thin film; The heating step comprises:

3. The method for manufacturing a chip according to claim 1, further comprising the step of heating the passivation film in addition to heating the insulating film and the thin film.

Images