Al single crystals were implanted with 150‐keV He+ions at room temperature to fluences high enough to produce several layers of exfoliation. Each exfoliated layer occurs by spalling of the entire bombarded crystal surface, and step height measurements show that the spalling occurs at a depth less than the calculated projected range of the He ions. Preliminary evidence from aligned backscattered (channeling) spectra of exfoliated crystals indicates that the He remaining in the crystal after spalling is in the form of bubbles.