Bond Breaking and the Ionization of Sputtered Atoms

We have studied the static-mode ion-beam sputtering of Si+ from a Si (100) surface during oxidation and nitridation. The data are consistent with the ionization of sputtered atoms resulting from the breaking of the local chemical bond during sputtering. A model is proposed to explain the dependences of the ionization probability of the ionization potential, emission energy, and isotopic mass. © 1986 The American Physical Society.