Comparison of diffusion and ion implantation: When we compare diffusion versus ion implantation, we should note the following: the deposition plus diffusion process depends on the chemical nature of the species and the solubility. We can never implant more than the solubility limit of the dopant by the diffusion process. In implantation, the doping depends on the energy of the ion beam. We can dope more than the solubility limit. Implantation is more expensive than diffusion. We can control the junction depth, and profile much better than implantation; we can also see or ensure that the maximum concentration of the dopant occurs inside in a specific location, whereas in diffusion, the maximum concentration will always occur on the surface. In the diffusion, the side diffusion is significant in ion implantation even though there is transverse struggle – the movement to the side is relatively less.