Effect of external bias potential on secondary charged emissions from polycarbonate by C_1~+ and C_8~+ bombardments

摘要

Atomic dose dependence of the secondary charged emission current during monoatomic ion C_1~+ and cluster ion C_8~+ bombardments to an organic insulator was measured at various external bias potentials. The secondary charged emission current for C_8~+ varied with the external bias potential at a relatively low dose (3 x 10~(11) atoms/cm~2). The external bias potential dependence of the charged emission current became weaker with increasing dose, and the emission current finally became equal to the injected beam current at a relatively high dose (1 x 10~(14) atoms/cm~2). The stabilization of the secondary emission current at 1 x 10~(14) atoms/cm~2 was observed for C_8~+ bombardment, but not for C_1~+ bombardment.