Formation of β-Be₃N₂ nanocrystallites in Be-implanted GaN

Abstract

A small Be ion dose of 5 × 1014 cm−2 was implanted in a 2 μm thick GaN epilayer at an energy of 50 keV. The sample was characterized by high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopy techniques after a post-implantation rapid thermal annealing (RTA) treatment. The HRTEM images show the crystallographic (1 1 0) and (0 0 2) planes of β-Be3N2. Two characteristic parallelograms drawn in Fast Fourier transform (FFT) image support the formation of β-Be3N2 nanocrystallites in RTA treated sample. Two Raman peaks at 168 and 199 cm−1 are observed in the Raman spectrum of the sample that are assigned to β-Be3N2 on the basis of group theory and HRTEM data. The Raman peak at 168 cm−1 is found close to the K point in the first Brillouin zone of β-Be3N2 while the peak at 199 cm−1 is assigned as a combination mode of the fundamental Raman modes of β-Be3N2.

Resonant Raman Scattering in Boron-Implanted GaN

“…The use of the ion-implantation technique, which allows the reliable and controllable introduction of ions to a defined region and is not limited by solid solubility, is a critical requirement for advances in GaN device technology. GaN epilayers have been implanted with many kinds of ions [7][8][9][10][11][12][13][14][15][16][17][18]. The microstructural, electrical, and optical properties of the ion-implanted GaN epilayers are critical to device performance.…”