A gas is ionized into a plasma. A compound of a dopant is mixed into the plasma, forming a mixed plasma. Using a semiconductor device fabrication system, a layer of III-V material is exposed to the mixed plasma to dope the layer with the dopant up to a depth in the layer, forming a shallow doped portion of the layer. The depth of the dopant is controlled by a second layer of the dopant formed at the shallow doped portion of the layer. The second layer is exposed to a solution, where the solution is prepared to erode the dopant in the second layer at a first rate. After an elapsed period, the solution is removed from the second layer, wherein the elapsed period is insufficient to erode a total depth of the layer and the shallow doped portion by more than a tolerance erosion amount.