Patent ID: 8012805

Claim:
A manufacturing method for semiconductor chips comprising: performing plasma etching on a second surface of a semiconductor wafer that has a first surface on which semiconductor devices placed in a plurality of device-formation-regions defined by dividing regions and an insulating film placed in the dividing regions are formed and the second surface on which a mask for defining the dividing regions is placed, the second surface being located opposite from the first surface, whereby portions that correspond to the dividing regions are removed and the insulating film is exposed from etching bottom portions; removing corner portions on the first surface side put in contact with the insulating film in the device-formation-regions by performing the plasma etching in a state in which exposed surfaces of the insulating film are charged with electric charge due to ions in plasma; and subsequently, removing the exposed insulating film so that the device-formation-regions are separated into individual semiconductor chips, whereby the semiconductor chips each of which includes the individualized semiconductor device are manufactured, wherein isotropic plasma etching is further performed from the second surface on the semiconductor wafer or the individual semiconductor chips with the mask placed at any timing before or after exposure of the insulating film, removal of the corner portions or removal of the insulating film is carried out.