[Granted] A method of plasma doping includes providing a dopant gas comprising a dopant heavy halogenide compound gas to a plasma chamber. A plasma is formed in the plasma chamber with the dopant heavy halogenide compound gas and generates desired dopant ions and heavy fragments of precursor dopant molecule. A substrate in the plasma chamber is biased so that the desired dopant ions impact the substrate with a desired ion energy, thereby implanting the desired dopant ions and the heavy fragments of precursor dopant molecule into the substrate, wherein at least one of the ion energy and composition of the dopant heavy halogenide compound is chosen so that the implant profile in the substrate is substantially determined by the desired dopant ions.