Calloni, A.; Ferragut, R.; Dupasquier, Alfredo; von Känel, H.; Guiller, A.; Rutz, A.; Ravelli, Luca; Egger, Werner
Dokumenttyp:
Zeitschriftenartikel / Journal Article
Titel:
Characterization of vacancy-type defects in heteroepitaxial GaN grown by low-energy plasma-enhanced vapor phase epitaxy
Zeitschrift:
Journal of Applied Physics
Jahrgang:
112
Heftnummer:
2
Jahr:
2012
Sprache:
Englisch
Abstract:
The defect concentration in thin GaN layers was estimated by means of positron annihilation spectroscopy. Positron lifetime and Doppler broadening of the annihilation radiation were used. A comparative study of GaN films grown with different techniques was performed. Specific attention has been given to the new low energy plasma enhanced vapor phase epitaxy (LEPEVPE) growth technique. A very high Ga vacancy density (10 19 cm -3) was found in a thin GaN layer directly grown by LEPEVPE on a sapphire substrate. However, when a GaN substrate (commercial sample grown by Metal Organic Vapor Phase Epitaxy) is used as a template for LEPEVPE deposition, the vacancy density of the film is low (about 10 16 cm -3). This fact provides evidences that the LEPEVPE technique is able to produce high quality GaN layers. «
The defect concentration in thin GaN layers was estimated by means of positron annihilation spectroscopy. Positron lifetime and Doppler broadening of the annihilation radiation were used. A comparative study of GaN films grown with different techniques was performed. Specific attention has been given to the new low energy plasma enhanced vapor phase epitaxy (LEPEVPE) growth technique. A very high Ga vacancy density (10 19 cm -3) was found in a thin GaN layer directly grown by LEPEVPE on a sapphi... »