Abstract
Abstract Methods to implant ions into the sidewall of a three dimensional high aspect ratio feature, such as a trench or via, are disclosed. The methods utilize a phenomenon known as knock-in, which causes a first species of ions, already disposed in the fill material, to become implanted in the sidewall when these ions are struck by ions of a second species being implanted into the fill material. In some embodiments, these first species and second species have similar masses to facilitate knock-in. In some embodiments, the entire hole is not completely filled with fill material. Rather, some fill material is deposited, an ion implant is performed to cause knock-in to the sidewall adjacent to the deposited fill material, and the process is repeated until the hole is filled.