Abstract: Multiphoton absorption is generated, so as to form a part which is intended to be cut 9 due to a molten processed region 13 within a silicon wafer 11, and then an adhesive sheet 20 bonded to the silicon wafer 11 is expanded. This cuts the silicon wafer 11 along the part which is intended to be cut 9 with a high precision into semiconductor chips 25. Here, opposing cut sections 25a, 25a of neighboring semiconductor chips 25, 25 are separated from each other from their close contact state, whereby a die-bonding resin layer 23 is also cut along the part which is intended to be cut 9. Therefore, the silicon wafer 11 and die-bonding resin layer 23 can be cut much more efficiently than in the case where the silicon wafer 11 and die-bonding resin layer 23 are cut with a blade without cutting a base 21.

Abstract: An object to be processed can be cut highly accurately along a line to cut. An object to be processed 1 is irradiated with laser light while locating a converging point within a silicon wafer 11, and the converging point is relatively moved along a line to cut 5, so as to form modified regions M1, M2 positioned within the object 1 along the line to cut 5, and then a modified region M3 positioned between the modified regions M1, M2 within the object 1.

Abstract: Multiphoton absorption is generated, so as to form a part which is intended to be cut 9 due to a molten processed region 13 within a silicon wafer 11, and then an adhesive sheet 20 bonded to the silicon wafer 11 is expanded. This cuts the silicon wafer 11 along the part which is intended to be cut 9 with a high precision into semiconductor chips 25. Here, opposing cut sections 25a, 25a of neighboring semiconductor chips 25, 25 are separated from each other from their close contact state, whereby a die-bonding resin layer 23 is also cut along the part which is intended to be cut 9. Therefore, the silicon wafer 11 and die-bonding resin layer 23 can be cut much more efficiently than in the case where the silicon wafer 11 and die-bonding resin layer 23 are cut with a blade without cutting a base 21.

Abstract: A laser processing device (100) comprises a laser light source (101) for emitting a laser light (L) and a laser light source controller (102) for controlling the pulse width of the laser light (L) and irradiates an object to be processed (1) with the laser light (L) while locating a converging point (P) within the object (1), so as to form a modified region along a line to cut (5) of the object (1) and generate a fracture extending in a thickness direction of the object (1) from the modified region as the modified region is formed. In the laser processing device (100), the laser light source controller (102) changes the pulse width of the laser light (L) according to a data table in which the fracture length, the thickness of the object (1), and the pulse width of the laser light (L) are associated with each other. That is, the pulse width is changed according to the fracture length generated from the modified region.

Abstract: An object to be processed 1 is irradiated with laser light L along a line to cut 5a while locating a converging point within the object 1, so as to form a modified region 7a. Thereafter, the irradiation with the laser light L is performed again along the line 5a, so as to form a modified region 7b between a front face 3 and the first modified region 7a in the object 1 and generate a fracture Cb extending from the modified region 7b to the front face 3. Therefore, a deflecting force F1 occurring when forming the modified region 7a in the object 1 can be released and canceled out by the fracture Cb. As a result, the object 1 can be inhibited from deflecting.

Abstract: A wafer having a front face formed with a functional device is irradiated with laser light while positioning a light-converging point within the wafer with the rear face of the wafer acting as a laser light incident face, so as to generate multiphoton absorption, thereby forming a starting point region for cutting due to a molten processed region within the wafer along a line. Consequently, a fracture can be generated from the starting point region for cutting naturally or with a relatively small force, so as to reach the front face and rear face. Therefore, when an expansion film is attached to the rear face of the wafer by way of a die bonding resin layer after forming the starting point region for cutting and then expanded, the wafer and die bonding resin layer can be cut along the line.

Abstract: A laser processing method is provided, which, when cutting a substrate formed with a multilayer part including a plurality of functional devices, makes it possible to cut the multilayer part with a high precision in particular. In a state where a protective tape 22 is attached to the front face 16a of a multilayer part 16, a substrate 4 is irradiated with laser light L while using its rear face 4b as a laser light entrance surface, so as to form a modified region 7 within the substrate 4 along a line to cut, thereby generating a fracture 24 reaching the front face 4a of the substrate 4 from a front-side end part 7a of the modified region 7. Attaching an expandable tape to the rear face 4b of the substrate 4 and expanding it in the state where such a fracture 24 is generated can cut not only the substrate 4 but also the multilayer part 16 on the line to cut, i.e., interlayer insulating films 17a, 17b, with a favorable precision along the line to cut.

Abstract: An object to be processed can be cut highly accurately along a line to cut. An object to be processed 1 is irradiated with laser light while locating a converging point within a silicon wafer 11, and the converging point is relatively moved along a line to cut 5, so as to form modified regions M1, M2 positioned within the object 1 along the line to cut 5, and then a modified region M3 positioned between the modified regions M1, M2 within the object 1.

Abstract: Multiphoton absorption is generated, so as to form a part which is intended to be cut 9 due to a molten processed region 13 within a silicon wafer 11, and then an adhesive sheet 20 bonded to the silicon wafer 11 is expanded. This cuts the silicon wafer 11 along the part which is intended to be cut 9 with a high precision into semiconductor chips 25. Here, opposing cut sections 25a, 25a of neighboring semiconductor chips 25, 25 are separated from each other from their close contact state, whereby a die-bonding resin layer 23 is also cut along the part which is intended to be cut 9. Therefore, the silicon wafer 11 and die-bonding resin layer 23 can be cut much more efficiently than in the case where the silicon wafer 11 and die-bonding resin layer 23 are cut with a blade without cutting a base 21.

Abstract: A method for cutting a semiconductor substrate having a front face formed with functional devices together with a die bonding resin layer. A wafer having a front face formed with functional devices is irradiated with laser light while positioning a light-converging point within the wafer with the rear face of the wafer acting as a laser light incident face, so as to form a starting point region for cutting due to a modified region within the wafer along a cutting line. When an expansion film is attached to the rear face by way of a die bonding resin layer after forming the starting point region and then expanded, a fracture can be generated from the starting point region which reaches the front face and rear face, consequently, the wafer and die bonding resin layer can be cut along the cutting line.

Abstract: An object to be processed can be cut highly accurately along a line to cut. An object to be processed 1 is irradiated with laser light while locating a converging point within a silicon wafer 11, and the converging point is relatively moved along a line to cut 5, so as to form modified regions M1, M2 positioned within the object 1 along the line to cut 5, and then a modified region M3 positioned between the modified regions M1, M2 within the object 1.

Abstract: A laser processing method is provided, which, when cutting an object to be processed comprising a substrate and a multilayer part, formed on a front face of the substrate, including a functional device, can cut the multilayer part with a high precision in particular. In a state where a protective tape 22 is attached to the front face 16a of a multilayer part 16, a substrate 4 is irradiated with laser light L while using its rear face 4b as a laser light entrance surface, so as to form a modified region 7 within the substrate 4 along a line to cut, thereby generating a fracture 24 reaching the front face 4a of the substrate 4 from a front-side end part 7a of the modified region 7. Attaching an expandable tape to the rear face 4b of the substrate 4 and expanding it in the state where such a fracture 24 is generated can cut not only the substrate 4 but also the multilayer part 16 on the line to cut, i.e., interlayer insulating films 17a, 17b, with a favorable precision along the line to cut.

Abstract: A semiconductor device is provided, which, when cutting a substrate formed with a multilayer part including a plurality of functional devices, makes it possible to cut the multilayer part with a high precision in particular. In a state where a protective tape 22 is attached to the front face 16a of a multilayer part 16, a substrate 4 is irradiated with laser light L while using its rear face 4b as a laser light entrance surface, so as to form a modified region 7 within the substrate 4 along a line to cut, thereby generating a fracture 24 reaching the front face 4a of the substrate 4 from a front-side end part 7a of the modified region 7. Attaching an expandable tape to the rear face 4b of the substrate 4 and expanding it in the state where such a fracture 24 is generated can cut not only the substrate 4 but also the multilayer part 16 on the line to cut, i.e., interlayer insulating films 17a, 17b, with a favorable precision along the line to cut.

Abstract: An object to be processed can be cut highly accurately along a line to cut. An object to be processed 1 is irradiated with laser light while locating a converging point within a silicon wafer 11, and the converging point is relatively moved along a line to cut 5, so as to form modified regions M1, M2 positioned within the object 1 along the line to cut 5, and then a modified region M3 positioned between the modified regions M1, M2 within the object 1.

Abstract: A laser processing method is provided, which, when cutting a substrate formed with a multilayer part including a plurality of functional devices, makes it possible to cut the multilayer part with a high precision in particular. In a state where a protective tape 22 is attached to the front face 16a of a multilayer part 16, a substrate 4 is irradiated with laser light L while using its rear face 4b as a laser light entrance surface, so as to form a modified region 7 within the substrate 4 along a line to cut, thereby generating a fracture 24 reaching the front face 4a of the substrate 4 from a front-side end part 7a of the modified region 7. Attaching an expandable tape to the rear face 4b of the substrate 4 and expanding it in the state where such a fracture 24 is generated can cut not only the substrate 4 but also the multilayer part 16 on the line to cut, i.e., interlayer insulating films 17a, 17b, with a favorable precision along the line to cut.

Abstract: A semiconductor substrate cutting method which can efficiently cut a semiconductor substrate having a front face formed with a functional device together with a die bonding resin layer is provided. A wafer 11 having a front face 3 formed with a functional device 15 is irradiated with laser light L while positioning a light-converging point P within the wafer 11 with the rear face 17 of the wafer 11 acting as a laser light incident face, so as to generate multiphoton absorption, thereby forming a starting point region for cutting 8 due to a molten processed region 13 within the wafer 11 along a line along which the substrate should be cut 5. Consequently, a fracture can be generated from the starting point region for cutting 8 naturally or with a relatively small force, so as to reach the front face 3 and rear face 17.

Abstract: An object to be processed can be cut highly accurately along a line to cut. An object to be processed 1 is irradiated with laser light while locating a converging point within a silicon wafer 11, and the converging point is relatively moved along a line to cut 5, so as to form modified regions M1, M2 positioned within the object 1 along the line to cut 5, and then a modified region M3 positioned between the modified regions M1, M2 within the object 1.

Abstract: In the laser processing method, the cross-sectional form of laser light L at a converging point P is such that the maximum length in a direction perpendicular to a line to cut 5 is shorter than the maximum length in a direction parallel to the line to cut 5. Therefore, when seen from the incident direction of the laser light L, a modified region 7 formed within a silicon wafer 11 has such a shape that the maximum length in the direction perpendicular to the line to cut 5 is shorter than the maximum length in the direction parallel to the line to cut 5. Forming the modified region 7 having such a shape within the object 1 can restrain twist hackles from occurring on cut surfaces when cutting the object 1 from the modified region 7 acting as a cutting start point, thereby making it possible to improve the flatness of the cut surfaces.

Abstract: A laser processing method is provided, which, when cutting a substrate formed with a multilayer part including a plurality of functional devices, makes it possible to cut the multilayer part with a high precision in particular. In a state where a protective tape 22 is attached to the front face 16a of a multilayer part 16, a substrate 4 is irradiated with laser light L while using its rear face 4b as a laser light entrance surface, so as to form a modified region 7 within the substrate 4 along a line to cut, thereby generating a fracture 24 reaching the front face 4a of the substrate 4 from a front-side end part 7a of the modified region 7. Attaching an expandable tape to the rear face 4b of the substrate 4 and expanding it in the state where such a fracture 24 is generated can cut not only the substrate 4 but also the multilayer part 16 on the line to cut, i.e., interlayer insulating films 17a, 17b, with a favorable precision along the line to cut.

Abstract: A laser processing method is provided, which, when cutting an object to be processed comprising a substrate and a multilayer part, formed on a front face of the substrate, including a functional device, can cut the multilayer part with a high precision in particular. In a state where a protective tape 22 is attached to the front face 16a of a multilayer part 16, a substrate 4 is irradiated with laser light L while using its rear face 4b as a laser light entrance surface, so as to form a modified region 7 within the substrate 4 along a line to cut, thereby generating a fracture 24 reaching the front face 4a of the substrate 4 from a front-side end part 7a of the modified region 7. Attaching an expandable tape to the rear face 4b of the substrate 4 and expanding it in the state where such a fracture 24 is generated can cut not only the substrate 4 but also the multilayer part 16 on the line to cut, i.e., interlayer insulating films 17a, 17b, with a favorable precision along the line to cut.