Improvement of sensitivity in high-resolution ERDA

Recently, we have developed a new detector system for a magnetic spectrometer to reduce the background noise in high-resolution Rutherford backscattering spectroscopy. The detector system consists of a MCP detector for ion detection, which has a thin Mylar foil in front of the detector, and an electron detector to detect secondary electrons emitted by the ions upon impact on the Mylar foil. By measuring the ion signal in coincidence with the electron signal, the dark noise of the ion detector can be efficiently rejected. This new detector system is used to improve the sensitivity of high-resolution elastic recoil detection. The detection limit of 0.08 at.% is achieved for the boron depth profiling in Si.