Secondary Ion Mass Spectrometry Protocols for Electrodeposited Copper Impurity Quantification
Dynamic SIMS protocols require cesium primary beams and oxygen flooding to accurately quantify trace sulfur, chlorine, and carbon in plated copper films.
Mass Resolving Power
Meaning
Quantitative performance metrics defined by the ratio of nominal mass to the peak width at a specified peak height express the ability of a mass spectrometer to separate adjacent mass spectral peaks. In surface mass spectrometry, mass resolving power quantifies whether an instrument can separate target secondary ion species from background isobaric overlaps. Higher values allow mass spectrometers to isolate structural doublet peaks separated by fractions of an atomic mass unit.
The boundary of this metric depends on ion optics design and entrance slit width adjustments.
Measurement Standard
Calculations evaluate peak separation using either the full width at half maximum definition or ten percent valley separation standards between equal intensity peaks. The formula divides observed nominal mass by peak full width at half maximum measured across calibrated spectral profiles. Higher numeric values indicate narrow peak profiles capable of resolving small mass differences between target atomic ions and molecular fragments.
Optical Parameter
Adjusting instrument entrance and exit slits directly alters peak shape, ion beam transmission efficiency and mass resolution metrics. Narrowing slit widths improves mass separation capabilities while reducing total ion signal intensity reaching the detector. Electrostatic analyzers compensate for kinetic energy spreads among secondary ions, maintaining high peak sharpness across magnetic sector flight paths.
Trade Calibration
Instrument verification protocols require demonstrated separation of silicon hydride and phosphorus mass peaks during factory acceptance testing.