High hole concentrations in Mg-doped InGaN grown by MOVPE

We investigated the electrical properties of Me-doped InxGa1-xN (0 less than or equal to x < 0.75) grown by metalorganic vapor-phase epitaxy with various growth conditions, such as Mg-doping concentration, growth-rate and growth temperature. The hole concentration depends on the growth-rate, the In mole fraction and the crystal quality of the InGaN layers. The hole concentration of Mg-doped InxGa1-xN layers below x = 0.15 increased with the In mole fraction, while those above x = 0.15 decreased. We realized the p-type InGaN with the room-temperature hole concentration above 10(18)cm(-3) and obtained the maximum hole concentration of 7.8 x 10(18) cm (-3) for x = 0.2 by optimizing the growth conditions. (C) 2000 Elsevier Science B.V. All rights reserved.