Homoepitaxial growth of catalyst-free GaN wires on N-polar substrates

Xiao Jun Chen (1) , Guillaume Perillat-Merceroz (2, 3) , Diane Sam-Giao (1) , Christophe Durand , Joël Eymery (1)

1 NPSC - Nanophysique et Semiconducteurs
2 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
3 LEMMA - Laboratoire d'Etude des Matériaux par Microscopie Avancée

The shape of c-oriented GaN nanostructures is found to be directly related to the crystal polarity. As evidenced by convergent beam electron diffraction applied to GaN nanostructures grown by metal-organic vapor phase epitaxy on c-sapphire substrates: wires grown on nitridated sapphire have the N-polarity ([000math]) whereas pyramidal crystals have Ga-polarity ([0001]). In the case of homoepitaxy, the GaN wires can be directly selected using N-polar GaN freestanding substrates and exhibit good optical properties. A schematic representation of the kinetic Wulff's plot points out the effect of surface polarity.

Mots clés: nitridation; electron diffraction; MOCVD; nanofabrication; nanowires; III-V semiconductors; semiconductor quantum wires; semiconductor growth; gallium compounds; vapour phase epitaxial growth; wide band gap semiconductors

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Xiao Jun Chen, Guillaume Perillat-Merceroz, Diane Sam-Giao, Christophe Durand, Joël Eymery. Homoepitaxial growth of catalyst-free GaN wires on N-polar substrates. Applied Physics Letters, 2010, 97 (15), pp.151909. ⟨10.1063/1.3497078⟩. ⟨hal-00601864⟩