Delta-Doping of Epitaxial GaN Layers on Large Diameter Si(111) Substrates
Résumé
We report on silicon n-type delta (δ)-doping of gallium nitride (GaN) epitaxial layers grown by metalorganic chemical vapor deposition (MOCVD) on silicon (111) substrates. In a series of group III–nitride epitaxial structures a ∼1-µm-thick Si bulk-doped GaN layer is replaced by 100, 50, 10, 5, or 1 Si δ-doped planes. While Si bulk-doping of GaN aggrandizes the in-plane tensile stress and the wafer bow with respect to undoped structures, δ-doping is found to reduce both stress and wafer bow. Two-dimensional carrier sheet densities between 10 12 and 10 13 cm -2 per δ-doped plane and electron mobilities of 1429 cm 2 V -1 s -1 are achieved.