Analysis of surface particles by time-of-flight secondary ion mass spectrometry

A major cause of semiconductor device failure is contamination of the device surface by particulate matters from process chemicals, airborne particles, or particles flaking off from process equipment. Particle sizes range from tens of micrometers to tens of nanometers in diameter. The new time-of-flight (TOF-SIMS) technique is well suited for this type of analysis because of its high sensitivity, excellent mass and lateral resolution, and unlimited mass range. As an illustration of its potential, data were acquired from different types of particles on solid substrates, and the results demonstrate direct in situ elemental and molecular microanalysis of submicrometer particulates.