Dynamic annealing in III-nitrides under ion bombardment

Abstract

Articles you may be interested inEffect of the growth temperature and the AlN mole fraction on In incorporation and properties of quaternary IIInitride layers grown by molecular beam epitaxy J. Appl. Phys.We study the evolution of structural defects in Al x Ga 1Ϫx N films ͑with xϭ0.0-0.6) bombarded with kilo-electron-volt heavy ions at 77 and 300 K. We use a combination of Rutherford backscattering/ channeling spectrometry and cross-sectional transmission electron microscopy. Results show that an increase in Al content not only strongly enhances dynamic annealing processes but can also change the main features of the amorphization behavior. In particular, the damage buildup behavior at 300 K is essentially similar for all the AlGaN films studied. Ion-beam-produced disorder at 300 K accumulates preferentially in the crystal bulk region up to a certain saturation level ͑ϳ50%-60% relative disorder͒. Bombardment at 300 K above a critical fluence results in a rapid increase in damage from the saturation level up to complete disordering, with a buried amorphous layer nucleating in the crystal bulk. However, at 77 K, the saturation effect of lattice disorder in the bulk occurs only for xտ0.1. Based on the analysis of these results for AlGaN and previously reported data for InGaN, we discuss physical mechanisms of the susceptibility of group-III nitrides to ion-beam-induced disordering and to the crystalline-to-amorphous phase transition.

Fermi level stabilization energy in cadmium oxide

“…In our He + irradiated sample the electron concentration saturates at about 18 19 . However, Kucheyev states that the two most likely mechanisms are an increase in electrostatic energy associated with substitutional disorder and electrostatically lowering energy barriers for defect interaction processes as ionicity increases 20 . What is known is that very ionic materials, such as ZnO, exhibit strong dynamic annealing, and ZnO and CdO have comparable ionicity 21 .…”

Investigation of blistering kinetics in hydrogen implanted aluminium nitride

“…For example, the minimum hydrogen dose required to observe surface blistering in Si, Ge or SiC is about 3 × 10 16 H + 2 cm −2 [11,13,14]. It is known from the literature that the group III nitrides such as AlN and GaN exhibit very efficient dynamic annealing of the implantation-induced defects [20][21][22][23][24]. In the process of blistering, the implanted hydrogen interacts with the implantation-induced damage inside the semiconductor lattice that ultimately leads to the formation of extended defects such as nanovoids/nanoplatelets [9,10,13,25].…”

The high sensitivity of InN under rare earth ion implantation at medium range energy

“…In their work on InGaN alloys, Kucheyev et al [33] pointed out the detrimental effect of indium on the structure stability, and they showed that an increase of the In content degrades the dynamic annealing efficiency during the ion implantation. eV/atom, respectively: these values correspond to experimental data reported in Ref.…”

“…The high resistance to amorphization of GaN and AlN has been ascribed to an efficient dynamic annealing during implantation [32,33] which enables the defect annihilation and the arrangement into an array of planar defects. In absence of dynamic annealing, the damage accumulation leads to a complete lattice disordering or to amorphization when each atom has been moved approximately one time (1 displacement per atom (dpa)).…”