Tracing of low-energy protons implanted in different Si crystal orientations by keV recoil detection in transmission geometry

The potential of recoil detection in transmission geometry in examining a possible preferential lattice site location of H atoms implanted into thin single crystalline silicon membranes is explored. Low-energy protons were directed onto the membranes along the 〈0 0 1〉 Si crystal axis, as well as in random orientation. Position-sensitive and time-resolved detection of recoiling hydrogen species from a pulsed beam of 280 keV ²²Ne⁺ primary ions was performed in a time-of-flight medium energy ion scattering system. From the primary beam incidence along different crystal axes, a preferential detection of recoiled hydrogen along the 〈0 1 1〉 axis can be revealed, as compared to the 〈0 0 1〉 axis. The present approach and possible future developments potentially enabling real-space location of interstitial hydrogen are discussed.