Amplitude Spread
Statistical analysis of the variation in signal amplitudes produced by a detector under ion bombardment provides valuable information about the electronic noise and ion energy spread. This variance is represented by the peak height distribution, which describes the frequency of different signal intensities recorded by the secondary ion mass spectrometer. It characterizes the output of the electron multiplier or microchannel plate during surface analysis of electronic materials.
Understanding this signal distribution allows technicians to distinguish true secondary ion counts from background electronic noise.
Sputter Calibration
Measuring the variation in pulse heights allows for the optimization of the detector voltage to ensure that all secondary ions are counted with high efficiency. During depth profiling of circuit board finishes, a stable peak height distribution prevents drift in the measured ion intensity over long analytical runs. When the detector voltage is calibrated incorrectly, the distribution shifts and leads to artificial variations in the chemical profiles of the thin coatings on the board.
Regular calibration ensures the quantitative accuracy of the surface composition data.
Signal Optimization
Adjustment of the discriminator threshold eliminates low-amplitude noise without sacrificing the signal of light elements. This step improves the signal-to-noise ratio during the measurement of organic residues on copper contacts.
