Product Code: PIC2008_M302

Innovative Laser Technology for Semiconductor Manufacturing -Stealth Dicing (Invited Paper)
Authors:
Etsuji Ohmura, Osaka University; Suita, Osaka Japan
Hideki Morita, Hamamatsu Photonics K.K.; Iwata Japan
Masayoshi Kumagai, Hamamatsu Photonics K.K.; Iwata Japan
Presented at PICALO 2008

When a permeable nanosecond pulse laser which is focused into the inside of a silicon wafer is scanned in the horizontal direction, a belt-shaped high dislocation density layer including partially polycrystalline region is formed at an arbitrary depth in the wafer. Applying tensile stress perpendicularly to this belt-shaped modified-layer, silicon wafer can be separated easily into individual chips without creating any damage to the wafer surface comparing with the conventional blade dicing method, because the internal cracks that spread from the modified layer up and down progress to the surfaces. This technology is called "stealth dicing" (SD), and attracts attentions as an innovative dicing method in semiconductor industries. SD is an optimum solution for a dicing process of MEMS because of dry processing. The formation mechanism of this modified layer has been investigated theoretically and it has been concluded that the high dislocation density layer and the internal crack are generated due to propagation of a thermal shock wave caused by laser absorption. In this paper, the theoretical principle of the modified layer formation in SD and its superior applications of SD are reviewed.