Pulsed laser ablation rates of 4H silicon carbide wafer substrates with nanosecond- and ultrashort-pulse lasers

The electric vehicle (EV) and lithium-ion (Li-ion) battery industries enjoy a symbiotic relationship, with growth on one side mutually benefitting the other. Linking the two is the power-electronics circuitry for managing the high voltages and currents involved. For this, silicon substrates are generally inadequate and manufacturers are using more suitable materials such silicon carbide (SiC), which is challenging due to its high mechanical hardness and brittleness. Laser scribing and cutting for die singulation is important as traditional mechanical saw dicing is difficult. In this work we consider both ultrashort pulse (USP) and nanosecond (ns) pulse lasers for ablation processing of SiC wafers, with optical wavelengths ranging from infrared (IR) to ultraviolet (UV). Volume ablation rates and efficiencies are determined, and the effect of pulse bursts is considered. Absolute volume ablation rates near 50 mm3/min are achieved.