Secondary ion emission and work function measurements over the transient region from n and p type Si under Cs + irradiation

Si + and Si − emissions from n and p type Si wafers (uniformly doped) during the initial stages of sputtering with Cs + ions (transient region) scale with work functions in an expontential fashion consistent with the electron tunneling model. Work functions were derived using the Kelvin probe method. The intensity–work function dependence is also shifted according to the initial work functions of these wafers. As a result, almost identical transient effects are exhibited, i.e. matrix ion intensities do not appear to scale with dopant concentrations. This implies that intensity–work function relations are substrate dependent. Cs + intensities were also studied.