LASER PROCESSING METHOD AND SEMICONDUCTOR CHIP

• Main Authors: SAKAMOTO, TAKESHI, FUKUMITSU, KENSHI
• Format: Patent
• Language: English; French; German
• Published: 18.03.2009
• Subjects: BASIC ELECTRIC ELEMENTS; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; SEMICONDUCTOR DEVICES; SOLDERING OR UNSOLDERING; TRANSPORTING; WELDING; WORKING BY LASER BEAM; WORKING CEMENT, CLAY, OR STONE; WORKING STONE OR STONE-LIKE MATERIALS

A laser processing method is provided, which, even when a substrate formed with a laminate part including a plurality of functional devices is thick, can cut the substrate and laminate part with a high precision. This laser processing method irradiates a substrate 4 with laser light L while using a rear face 21 as a laser light entrance surface and locating a light-converging point P within the substrate 4, so as to form modified regions 71, 72, 73 within the substrate 4. Here, the HC modified region 73 is formed at a position between the segmented modified region 72 closest to the rear face 21 and the rear face 21, so as to generate a fracture 24 extending along a line to cut from the HC modified region 73 to the rear face 21. Therefore, when an expandable tape is bonded to the rear face 21 of the substrate 4 and expanded, fractures smoothly advance from the substrate 4 to a laminate part 16 by way of the segmented modified regions 72, whereby the substrate 4 and laminate part 16 can be cut along the line to cut with a high precision.