Quadrupole SIMS Analysis of Si Concentration in GaN Layers by a Molecular Ion Detection with a Minor Isotope

Abstract

The optimal condition suitable for using a quadrupole SIMS (Q-SIMS) instrument to measure the Si concentration in GaN layers for both selectively isotopic Si-implanted GaN and epitaxially Si-doped GaN was presented. The detection of 30 Si 14 N -molecular ions under Cs + primary ion bombardment realized the best dynamic range and the lowest detection limit for Q-SIMS analysis of Si in GaN layers. The detection limits of selectively isotopic 30 Si and the total amount of Si naturally occurring isotopes in GaN layers can reach 2  10 14 cm -3 and 8  10 15 cm -3 , respectively. We concluded that a Q-SIMS instrument was applicable for the analysis of the Si depth distribution in GaN layers.