Optimization of ion-atomic beam source for deposition of GaN ultrathin films

Optimization of ion-atomic beam source for deposition of GaN ultrathin films

Článek WoS

We describe the optimization and application of an ion-atomic beam source for ion-beam-assisted deposition of ultrathin films in ultrahigh vacuum. The device combines an effusion cell and electronimpact ion beam source to produce ultra-low energy (20–200 eV) ion beams and thermal atomic beams simultaneously. The source was equipped with a focusing system of electrostatic electrodes increasing the maximum nitrogen ion current density in the beam of a diameter of 15 mm by one order of magnitude (j 1000 nA/cm2). Hence, a successful growth of GaN ultrathin films on Si(111) 7 x 7 substrate surfaces at reasonable times and temperatures significantly lower (RT, 300 C) than in conventional metalorganic chemical vapor deposition technologies (1000 C) was achieved. The chemical composition of these films was characterized in situ by X-ray Photoelectron Spectroscopy and morphology ex situ using Scanning Electron Microscopy. It has been shown that the morphology of GaN layers strongly depends on the relative Ga-N bond concentration in the layers.

We describe the optimization and application of an ion-atomic beam source for ion-beam-assisted deposition of ultrathin films in ultrahigh vacuum. The device combines an effusion cell and electronimpact ion beam source to produce ultra-low energy (20–200 eV) ion beams and thermal atomic beams simultaneously. The source was equipped with a focusing system of electrostatic electrodes increasing the maximum nitrogen ion current density in the beam of a diameter of 15 mm by one order of magnitude (j 1000 nA/cm2). Hence, a successful growth of GaN ultrathin films on Si(111) 7 x 7 substrate surfaces at reasonable times and temperatures significantly lower (RT, 300 C) than in conventional metalorganic chemical vapor deposition technologies (1000 C) was achieved. The chemical composition of these films was characterized in situ by X-ray Photoelectron Spectroscopy and morphology ex situ using Scanning Electron Microscopy. It has been shown that the morphology of GaN layers strongly depends on the relative Ga-N bond concentration in the layers.

Ion souce; Atomic source; GaN; Surfaces

Ion souce; Atomic source; GaN; Surfaces

MACH, J.; ŠAMOŘIL, T.; KOLÍBAL, M.; ZLÁMAL, J.; VOBORNÝ, S.; BARTOŠÍK, M.; ŠIKOLA, T.

2017

15.08.2014

0034-6748

REVIEW OF SCIENTIFIC INSTRUMENTS

85

8

Spojené státy americké

083302-1

083302-5

5