Titanium (Ti) Schottky barrier diodes on epitaxially grown boron-dopedp-type Si films with a free carrier density of6–8×1016 cm−3were irradiated with alpha particles at room temperature using an americium-241 (Am-241) radio nuclide. We report the electronic and transformation characteristics of an &agr;-particle irradiation-induced defectH&agr;2in epitaxially grownp-Si with metastable properties. The energy level and apparent capture cross section, as determined by deep-level transient spectroscopy, areEv+0.43 eVand1.4×10−15 cm2,respectively. This defect can be removed and re-introduced using a conventional bias-on/off cooling technique. ©1998 American Institute of Physics.