Suppression of Backside Damage in Stealth Dicing

This paper describes a technique for minimizing damage during singulation of wafers using a laser dicing method called Stealth Dicing. We developed a TEG wafer, having multiple wiring lines of Ti/TiN/AlCu layers, to monitor laser damage. The wiring lines were designed so that the change in wiring resistance caused by scattered light could be measured. Laser damage evaluation was carried out at a laser light wavelength of 1342 nm, which has high transmittance in Si wafers. We confirmed that the width of the laser-damaged region could be suppressed to less than 20 μm by optimizing the laser focal position and laser power. By applying this Stealth Dicing technology, damage-free dicing can be achieved, and high-yield singulation for mass production can be expected.