The use of low temperature Si molecular beam epitaxy (MBE) has been investigated for the formation of 10 nm ultrashallow doped layers. Uniformly B-doped Si1-xGex(x=0, 0.2, or 0.4) layers have been studied. The sheet resistance of the optimally doped, as-grown samples were substantially less than the best reported, ion-implanted shallow layers. The MBE-grown shallow-doped layers were not affected by 10 min of thermal processing up to 700degreesC. (C) 2003 The Electrochemical Society.