Growth of Si-doped GaN Nanowires With Low Density For Power Device Applications

In this work, the growth of low-density self-catalyzed n-doped gallium nitride (GaN) nanowires (NWs) on Si(111) substrate has been investigated for power device applications. In the first part of this study, the influence of the growth temperature on the morphology and the density of the NWs has been studied. We have found that the NWs density can be reduced to 1.55×10 ⁹ NWs/cm ² at low growth temperature. However, under these conditions, a 1560 nm thick parasitic layer is also grown connecting the NWs by their bottom. To minimize this parasitic growth, we have developed a two-step growth procedure allowing us to maintain the NWs density around 1.91×10 ⁹ NWs/cm ² , while minimizing the parasitic layer’s thickness to 158 nm. In the second part, we have optimized the growth conditions to keep the NW characteristics (low density and thin parasitic layer) while inducing their n-type doping using silicon.