Method for manufacturing semiconductor chip and semiconductor device

A method for manufacturing a semiconductor chip by dividing a semiconductor wafer having a plurality of circuit patterns formed on one surface into pieces, said method comprising:

• forming a groove in a boundary region between the circuit patterns from an other surface of the semiconductor wafer by using a blade;
• forming a modified layer in the boundary region between the circuit patterns by laser irradiation from the one or the other surface of the semiconductor wafer;
• and
• dividing the semiconductor wafer into pieces by breaking the modified layer,
• wherein the modified layer is formed between a bottom surface of the groove and the one surface of the semiconductor wafer, and a width of the modified layer is smaller than a width of the groove,
• wherein the circuit patterns include an area that comprises a film with a dielectric constant that is lower than a dielectric constant of SiO2, and
• wherein, in a plan view, the area of the circuit patterns overlaps with the bottom surface of the groove.