Low temperature homoepitaxy of GaN by LP-MOVPE using Dimethylhydrazine and Nitrogen

Corinne Sartel (1) , Simon Gautier (1) , S. Ould Saad Hamady (1) , N. Maloufi (2) , Jérôme Martin (1) , Andrei Sirenko (3) , Abdallah Ougazzaden (4)

1 LMOPS - Laboratoire Matériaux Optiques, Photonique et Systèmes
2 LETAM - Laboratoire d'étude des textures et application aux matériaux
3 NJIT - New Jersey Institute of Technology [Newark]
4 ECE GeorgiaTech - School of Electrical and Computer Engineering - Georgia Insitute of Technology

Thin films of GaN with the V/III≈10 ratio were grown by low-pressure metal organic vapour phase epitaxy (LP-MOVPE) using N2 and Dimethylhydrazine (DMHy) as a carrier gas and nitrogen precursor, respectively. For the growth temperatures in the range from 550 to 690 ∘C the GaN layers exhibited good surface morphology. In the temperature range from approximately 550 to 610 ∘C, the growth rate increases with increasing temperature, characteristic of the process limited by surface kinetics with the activation energy of approximately 36 kcal/mol. For the temperatures between 620 and 690 ∘C, the growth rate was nearly independent of temperature, which is indicative of a mass transport limited growth. The activation energy was about 4.6 kcal/mol. Micro Raman spectroscopy revealed a significant relaxation of the selection rules for the scattering by the optical phonons in the films grown at lower temperatures. Variation of the intensity ratio for and phonon modes has been attributed to the changes in the structural quality of the films grown at different temperatures.

Mots clés: LP-MOVPE; GaN; DMHy; Micro-Raman spectroscopy

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

Corinne Sartel, Simon Gautier, S. Ould Saad Hamady, N. Maloufi, Jérôme Martin, et al.. Low temperature homoepitaxy of GaN by LP-MOVPE using Dimethylhydrazine and Nitrogen. Superlattices and Microstructures, 2006, 40, pp.476-482. ⟨10.1016/j.spmi.2006.09.026⟩. ⟨hal-00181631⟩