Patent ID: 7179722
Filing Date: 2007-02-20
Classification: H01L

Abstract:
1. A method of dividing, along dividing lines, a semiconductor wafer having function elements formed in areas sectioned by dividing lines formed in a lattice pattern on the front surface, comprising: a protective member affixing step for affixing a protective member to the front surface of the semiconductor wafer; a polishing step for polishing the back surface of the semiconductor wafer having the protective member affixed to the front surface; a deteriorated region formation step for forming deteriorated regions along the dividing lines with a pulse laser beam having a wave length of 1064 nm that passes through the semiconductor wafer from the polished back surface side of the semiconductor wafer, said deteriorated region formation step including applying the beam to a selected region inside the wafer to make the semiconductor material molten and thereafter removing the beam from the selected region such that the semiconductor material thereof re-solidifies, and repeating said applying and removing to another selected region inside the wafer to thereby form said deteriorated regions; a frame holding step for affixing the back surface of the semiconductor wafer in which the deteriorated regions have been formed along the dividing lines, to a dicing tape mounted on an annular frame; a dividing step for dividing the semiconductor wafer held on the annular frame into individual chips along the dividing lines by exerting external force along the dividing lines where the deteriorated regions have been formed; an expansion step for enlarging the interval between chips by stretching with a stretching member the dicing tape affixed to the semiconductor wafer divided into individual chips; and a pick up step for picking up the chips from the stretched dicing tape.