An experimental study on dicing 28 nm low-k water using laser grooving technique

Abstract

For a nanoscale low-k dielectric wafer, Inter-Layer Dielectric and metal layers peelings, cracks, chipping, and delamination are the most common dicing defects by traditional blade sawing process. This paper demonstrates an investigation on uv laser grooving on low-k dielectric 65-, 45-, and 28-nm wafers. A series of parametric study on input laser power, frequency, grooving feed speed, defocus amount and street index has been conducted to improve dicing quality. The effects of the laser kerf geometry, grooving edge quality and defects are evaluated by using scanning electron microscopy (SEM) and focused ion beam (FIB). Experimental results have shown that the laser grooving technique is capable to improve the quality and yield issues in low-k wafer dicing process.