Quality and reliability aspects in the singulation of complex wafers containing low-k, copper and TEGs in the streets

A process is presented for the singulation of complex wafers containing low-k, copper and TEGs in the streets. The method is based upon a novel scribing process using a carbon dioxide laser in which a thin top layer of non-silicon elements is removed, followed by a mechanical dicing step that cuts completely through the remaining thickness of the wafer. The impact of laser scribing on cut quality and resulting die strength is discussed and is compared to that of a traditional two-step dicing process. The different alternatives available to the end-user are presented, and the relevant quality, reliability and cost considerations are discussed in depth. Two cases studies are presented in which the technology is applied to different wafer types.