The Behavior of Ion-Implanted Hydrogen in Gallium Nitride

Abstract

Hydrogen was ion-implanted into wurtzite-phase GaN, and its transport, bound states, and microstructural effects during annealing up to 980ºC were investigated by nuclear-reaction profiling, ion-channeling analysis, transmission electron microscopy, and infrared (IR) vibrational spectroscopy. At implanted concentrations ∨1 at.%, faceted H 2 bubbles formed, enabling identification of energetically preferred surfaces, examination of passivating N-H states on these surfaces, and determination of the diffusivity-solubility product of the H. Additionally, the formation and evolution of point and extended defects arising from implantation and bubble formation were characterized. At implanted H concentrations ∧0.1 at.%, bubble formation was not observed, and ion-channeling analysis indicated a defect-related H site located within the [0001] channel.

Lattice location of hydrogen in Mg doped GaN

“…5͒, consistent with reversible release from a state with chemical potential higher than that of H 2 gas in bubbles. 36 The H release rate was slower than predicted 37 for release from interstitial molecular H 2 . It therefore appears that some state other than H 2 gas or interstitial molecules is forming at a chemical potential lower than that required to nucleate gas bubbles.…”

Defect clustering in GaN irradiated with O+ ions

“…[4][5][6][7][8][9][10][11][12] Ion implantation is a critical technique to spatially dope selective donor and acceptor ions into GaN for fabrication of advanced optoelectronic devices. These efforts include the development of appropriate methods for growing high-quality, single-crystal GaN thin films, 1,2 the correlation of its electrical and optical properties with its microstructure, 1,3 and ion-implantation-related phenomena.…”

Helium implanted gallium nitride evidence of gas-filled rod-shaped cavity formation along the c-axis

“…Upon annealing at temperature above 800°C, H outgases from the matrix and faceting of the cavities appear. 32 These cavities form polyhedrons with apexes always pointed toward the substrate. Similar cavities, referred as nanovoids, have also been observed after He implantation followed by a rapid thermal annealing into GaN.…”