Ion channeling in GaAs: Si, S, Se, and Te

Atom depth distributions resulting from the implantation of 29Si, 32S, 32Se, and 130Te ions within ∼0.05° of the 〈110〉 and 〈100〉 directions of the GaAs crystal have been measured by secondary-ion mass spectrometry. The two lower-mass ions were implanted at 150 keV and the two higher-mass ions at 300 keV; all were implanted to a fluence of 3.0×1013 cm−2. Well-defined maximum ranges and most probable channeled ranges Rc are observed in the 〈110〉 channeled distributions. The values of R0.1Nmax at Rc, chosen as a measure of the maximum channeled range, are 2.60, 1.60, 3.56, and 4.68 um, respectively, for the four ions. Background-subtracted detection sensitivities for these four atoms in GaAs of l013–3×1014 cm−3 provide up to five orders of magnitude of dynamic range below the maxima in the depth distributions (the peaks in the random components).