Journal of Crystal Growth 272 (2004) 466–474 OpticalandstructuralstudiesofGaN3Dstructuresselectively grown by MOCVD P. Viste a , I. Colombier b , F. Donatini b , J.C. Vial b , P. Baldeck b , R. Herino b , A.Duc-Mauge´ c , J. Godfroyd c , Y. Lacroute a , M. Sacilotti a,Ã a Lab. de Physique, Couches Minces et Nanostructures group, FR CNRS 2604 and LPUB, Universite de Bourgogne, 9, Av. Alain Savary, BP 400, BP 47870, Dijon Cedex 21078, France b Laboratoire de Spectrome´trie Physique, Universite de Joseph Fourier, Grenoble, France c RSA LE RUBIS SA BP 16, 38560 Jarrie, Cedex, France Available online 12 October 2004 Abstract This paper presents preliminary results on the selective growth of three-dimensional (3D) micrometric metallic structures by the MOCVD technique. The 3D structure growth occurs by simply feeding the reactor gas phase with a conventional flow of metal-organic (MO), trimethyl-gallium (TMGa) molecules. Selectivity occurs at the substrate surfaceinwhichMOspeciestraveltensofmicrometersinordertobuildupthe3Dstructure.Afterthegrowth,these structuresarenitridedinordertogiveGaN-relatedopticalvisibleemission.Opticalemissionresultsarepresentedand discussed in this paper. Both 3D structures deposition and annealing experiments can be extended to other III–V materials. r 2004 Elsevier B.V. All rights reserved. PACS: 68.90+g; 81.05.Bx; 81.15.Gh; 68.37.Hk; 61.10.Nz; 64.60.My Keywords: A1. Microstructure; A3. Metal-organic chemical vapor deposition; A3. Metal-organic vapor phase epitaxy; B1. GaN; B1. Metal-organic; B1. Metallic structures. 1. Introduction The selective growth of GaN three-dimensional (3D) submicrometric structures can be one of the important technological steps used for building quantumwiresanddots,opticalcavities,andwave guides in order to improve optical-device perfor- mance [1–4].Thesequantumstructuresaremainly constructedbyMOCVDandMBEwithpyramids or prism-like shapes [2,4]. Selective metal deposi- tionhasbeenachievedbytheuseofmetal-organic (MO) aluminum compounds on suitably prepared siliconsubstrates [5,6].Newmethodsandmechan- isms to selectively prepare 3D structures may be ARTICLE IN PRESS www.elsevier.com/locate/jcrysgro 0022-0248/$-see front matter r 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.jcrysgro.2004.09.002 Ã Corresponding author. Tel.: +33380395908; fax: +33380396013. E-mail address: msacilot@u-bourgogne.fr (M. Sacilotti).