Patent ID: 8420498
Filing Date: 2013-04-16
Classification: H01L

Abstract:
1. An alignment method of chips that are formed on a surface of a semiconductor wafer, each of the chips having alignment marks, the method comprising the steps of: irradiating an alignment mark provided to a predetermined alignment chip located in a predetermined alignment area including a plurality of the chips with a laser light, said semiconductor wafer being divided into a plurality of the predetermined alignment areas; detecting reflected waves from the alignment mark of the predetermined alignment chip to obtain a position of the alignment mark of the predetermined alignment chip; irradiating an alignment mark provided to an alternative chip adjacent to the predetermined alignment chip with the laser light if the position of the alignment mark of the predetermined alignment chip is not obtained, said alternative chip being located in the predetermined alignment area to which the predetermined alignment chip belongs, a position of the alignment mark of the alternative chip relative to an entirety of the alternative chip being a same as a position of the alignment mark of the predetermined alignment chip relative to an entirety of the predetermined alignment chip; obtaining a position of the alignment mark of the alternative chip by detecting the reflected waves from the alignment mark of the alternative chip; and aligning all of the plurality of the chips in the predetermined alignment area at one time based on positions of the alignment marks of the predetermined alignment chip and the alternative chip wherein, when the reflected waves from the alignment mark of the alternative chip are not detected, the method further comprises the step of: irradiating an alignment mark of another alternative chip adjacent the predetermined alignment chip with the laser light and continuing to change the predetermined alignment chip to be irradiated by the laser light within the predetermined alignment area until the reflected waves are detected within a predetermined time or area, wherein all of the chips in the predetermined alignment area are aligned at one time based on positions of the alignment marks whose reflected waves have been detected, and the predetermined alignment chip from which the reflected waves are not detected is not used for the alignment of all of the chips in the predetermined alignment area, wherein each of the alignment marks provided to the chip includes a metal part, said metal part being formed of aluminum; wherein, said alignment mark of the alternative chip is formed of a same material as that of the predetermined alignment chip.