| abstract |
After grinding the semiconductor wafer 1, the surface S side of the semiconductor wafer 1 is opposed to the electrostatic chuck 9 to fix the semiconductor wafer 1 to the electrostatic chuck 9. Next, in the state where the surface protection tape 3 is bonded, the mask material layer is formed in the back surface B of the ground semiconductor wafer 1. Next, the laser is irradiated to the part corresponding to the various streets suitably formed in the grid | lattice form etc. on the pattern surface 2 from the back surface B side, the mask tape 11 is cut | disconnected, and the street of the semiconductor wafer 1 is opened. do. Next, SF 6 plasma is irradiated from the back surface B side to etch the semiconductor wafer 1 exposed from the street portion. Next, ashing is performed by the O 2 plasma 19. |