Methods of forming a semiconductor structure include the use of channeled implants into silicon carbide crystals. Some methods include providing a silicon carbide layer having a crystallographic axis, heating the silicon carbide layer to a temperature of about 300° C. or more, implanting dopant ions into the heated silicon carbide layer at an implant angle between a direction of implantation and the crystallographic axis of less than about 2°, and annealing the silicon carbide layer at a time-temperature product of less than about 30,000° C.-hours to activate the implanted ions.