Abstract

Silicon carbide (SiC) is a wide-gap semiconductor which presents unique material properties especially suitable for high temperature, high power and high frequency applications. However, SiC device fabrication has to face to various technological difficulties. Among them, one of the more crucial appears to be the doping step. The high melting point and limited diffusion of impurities into SiC have greatly restricted the use of ion implantation and furnace annealing commonly employed in the silicon microelectronics industry to incorporate and activate the dopants. As an alternative to classical thermal heating, laser processing was recently demonstrated to be suitable for the doping of SiC. The use of high powerful pulsed laser beams in the nanosecond duration regime allows to deposit a large amount of energy in short time into the near-surface region, while maintaining the substrate essentially at room temperature. Under suitable conditions, the irradiation leads to the surface melting to a depth not exceeding a few hundred of nanometers, and resolidification from the bulk with high solid-liquid interface velocities of several meters / second. The melting threshold, melt depth and melting duration depend on a complicated manner on the different parameters involved in the interaction between the incident laser beam and semiconductor.

© 2000 IEEE