Secondary Ion Mass Spectrometry (SIMS) is a technique used in materials science to study the composition of thin films and solid surfaces by sputtering the sample’s surface with a focused primary ion beam. In recent years, there has been an increasing interest in studying dopants and contaminants in thin layers near surface in samples, as the device structures get smaller and smaller.
SIMS can be used for examining the elementary composition of the surface as well as near surface region of samples with sensitivity down to parts per billion. In order to get the maximum performance from the device, atmospheric contaminants with low atomic weight such as and oxygen (O), carbon (C), and hydrogen (H) should have low concentration levels.
SIMS: A High Sensitivity Surface Analysis Technique
In SIMS analysis, contamination of hydrocarbons on the surface of the sample to be assessed may produce incorrect results. Hydrocarbons exist abundantly in ambient atmosphere and often deposit on the surface of samples when exposed to air.
During SIMS analysis, the atmospheric contamination on the surface can be embedded into the sample by means of a primary ion beam; this contamination leads to distorted or spurious profiles. Therefore, it is very important for operators to know whether they are determining the surface’s composition or just viewing an artifact caused by contamination. Read More