Characterizing SIMS transient effects apparent in matrix secondary ion signals from silicon under 1 keV Cs+ impact

The low energy Si2-, Si3- and Si4- secondary ion signals resulting from Cs+ impact on Si appear to scale with the Cs uptake noted over the SIMS transient region in a manner consistent with the electron tunneling model. These populations, particularly Si3- and Si4- also exhibit a relative insensitivity to the presence of O (shown once sputter rate variations are accounted for). Profiles that more closely match the expected Si concentration gradient from a native oxide terminated Si wafer present within the SIMS transient region can also be obtained by simply dividing the Si3- or Si4- secondary ion intensities by the Si2- intensities. This suggests a possible alternative route for reducing transient effects present in the negative secondary ion populations from Si wafers