The silicon carbide (SiC) power device market is experiencing double-digit growth due to the benefits of SiC in boosting power efficiency and minimizing energy loss in applications such as automotive electric vehicles (EVs) and hybrid EVs, power supplies and solar inverters.
The formation of ohmic contacts on the backside of SiC power devices plays a key role in defining the electrical characteristics and mechanical strength of the device. Traditionally, thermal annealing processes using flash lamps with millisecond pulses have been used for OCF on the backside of SiC wafers.
Because this process requires temperatures of upwards of 1000° C, which can be detrimental to structures on the front side of the wafers, flash lamps are limited to wafer thicknesses of 350 microns and above.
As the industry now migrates to thinner SiC power devices for improved electrical performance and thermal management, new annealing solutions are needed that minimize these thermal effects. Laser annealing using UV nanosecond pulses provides the high precision and repeatability needed for OCF on the backside of SiC wafers, while ensuring no thermal damage to the wafer frontside that can negatively affect device performance.