The present disclosure relates to an integrated chip. The integrated chip includes a first III-V semiconductor material over a substrate and a second III-V semiconductor material over the first III-V semiconductor material. The second III-V semiconductor material is a different material than the first III-V semiconductor material. A doped region has a horizontally extending segment and one or more vertically extending segments protruding vertically outward from the horizontally extending segment. The horizontally extending segment is arranged below the first III-V semiconductor material.