A novel solid-state microwave annealing technique is developed for post-implantation annealing of silicon carbide (SiC) and Gallium Nitride (GaN), and for the controlled growth of SiC nanowires. This technique is capable of heating SiC samples to temperatures in excess of 2100 ºC, at ultra-fast temperature ramping rates > 600 ºC/s. For phosphorus and aluminum implanted SiC, sheet resistances as low as 14 Ω/sq and 1.9 kΩ/sq and majority carrier mobilities as high as 100 cm2/Vs and 8.3 cm2/Vs, respectively, are obtained. For the Al+ -implanted SiC, hole mobilties as high as 8.3 cm2/Vs is obtained. These values constitute the best ever reported electrical characteristics for high-dose ion-implanted SiC. Microwave annealing of in-situ as well as ion-implantation acceptor doped GaN was performed in the temperature range of 1200 ºC - 1600 ºC, for a duration of 5 s, using different protective caps (AlN, MgO, graphite). A patented, metal catalyst assisted sublimation sandwich method is invented for the growth of microwave-heating assisted cubic 3C-SiC nanowires.