Development of an electron electron ion coincidence analyzer for Auger photoelectron coincidence spectroscopy (APECS) and electron ion coincidence (EICO) spectroscopy

We have developed an electron electron ion coincidence (EEICO) analyzer for Auger photoelectron coincidence spectroscopy (APECS) and electron ion coincidence (EICO) spectroscopy. It consists of a coaxially symmetric mirror electron energy analyzer (coASMA), a miniature cylindrical mirror electron energy analyzer (CMA), a miniature time-of-flight ion mass spectrometer (TOF-MS), a xyz stage, a tilt-adjustment mechanism, and a conflat flange with an outer diameter of 203 mm. A sample surface is irradiated by synchrotron radiation, and emitted electrons are energy-analyzed and detected by the coASMA and the CMA, while desorbed ions are detected by the TOF-MS. The performance of the new EEICO analyzer was tested by measuring Si-LVV-Si-2p APECS data of clean Si(1 1 1)7 × 7 and Si(1 1 1)7 × 7 covered by dissociated H2O, and by measuring the Auger-electron photoion coincidence (AEPICO) spectra of condensed H2O at the 4a1 ← O 1s resonance.