Surface investigation of Si(100), Cu, Cu on Si(100), and Au on Cu with positron annihilation induced Auger-electron spectroscopy

Analytical Methods Using a Positron Microprobe

“…Figure 5 shows the PAES and EAES spectra for a clean Si(100) surface and for Si(100) covered with Cu. 36 The Si L2,3VV-Auger peak of pure Si can be clearly seen in the PAES and EAES results. For the Cu-covered sample, the Cu M2,3VV-Auger transition peak appears in addition to the Si peak.…”

Study of the surface contamination of copper with the improved positron annihilation-induced Auger electron spectrometer at NEPOMUC

“…Although the intensity of the 20 eV-beam has also been reduced to 2 Â 10 6 e + /s at the sample site, the preconditions for the PAES apparatus have been improved: using the primary positron beam, only a fraction of the emitted electrons had been detected due to the solid angle of only 8 Â 10 À3 sr and the small acceptance area of the actual electron energy analyzer (CLAM 2). Due to the higher brightness of the remoderated beam, more electrons can be analyzed and less electron background is produced at the magnetic field termination [6].…”

“…sample chamber, where they are nonadiabatically extracted and then focused onto the sample by electric lenses [6,7]. The sample can be biased and was set to À7 V in all presented measurements.…”

Recent development of the PAES set up at NEPOMUC

“…The current set up of NEPOMUC produces 9 · 10 8 primary positrons per second [4]. That lead to a reduction of the typical measurement time for a PAES spectrum to 10-12h [5].…”

“…• a high solid angle is covered and reduces the measurement time compared to the previous set up [5] considerably. Table 1 The first measurements (Fig.…”