Dynamic Secondary Ion Mass Spectrometry (D-SIMS) Alters the Limitations of Surface Analysis

Principles of D-SIMS Technology

Dynamic Secondary Ion Mass Spectrometry (D-SIMS) is an advanced surface analysis technique. It involves bombarding the sample surface with high-energy ions to generate trace amounts of secondary ions. These secondary ions are then detected and analyzed by a mass analyzer to obtain information about the chemical composition and structure of the sample surface. Compared to traditional surface analysis techniques, D-SIMS offers advantages such as high resolution, sensitivity, and depth profiling capabilities, making it widely applicable in scientific research and industrial settings. D-SIMS technology is based on the interaction between primary ions and the sample surface. When the sample surface is bombarded by primary ions, atoms or molecules on the surface absorb energy and are ejected, forming secondary ions with positive or negative charges. These secondary ions are then extracted and enter the mass analyzer. By detecting the mass-to-charge ratio of the secondary ions, information about the chemical composition and structure of the sample surface can be obtained.

Figure 1: Sims image of reticular silicon wafer

Advantages

1. High Resolution: D-SIMS provides high resolution, enabling sub-micron spatial resolution and nanometer-level depth resolution for a detailed analysis of the chemical composition and structure of the sample surface.
2. High Sensitivity: D-SIMS has high sensitivity, capable of detecting trace elements at ppm (parts per million) or even ppb (parts per billion) levels. This is crucial for analyzing trace impurities and biomolecules on the sample surface.
3. Depth Profiling Capability: D-SIMS can perform depth profiling of samples. As atoms or molecules on the sample surface are ejected during primary ion bombardment, the density of atoms or molecules gradually decreases with increasing depth, providing information about the sample's depth profile.
4. Elemental Coverage: D-SIMS can comprehensively analyze the sample surface, not only identifying the types of elements but also analyzing the isotopic composition and abundance of elements, thereby obtaining more comprehensive chemical information.

Applications

1. Materials Science: D-SIMS is used to analyze the surface composition, doping concentration, and crystal structure of materials, providing valuable insights into material properties and preparation processes.
2. Biology: D-SIMS is employed for the analysis of biological tissues, cells, proteins, and other biomolecules, facilitating the study of the structure and function of biological entities.
3. Chemistry: D-SIMS is applied to analyze intermediates and by-products in chemical reaction processes, revealing the mechanisms of chemical reactions.
4. Semiconductor Industry: D-SIMS is utilized for analyzing surface contamination defects in semiconductor devices, studying element doping, and is crucial for enhancing the performance and reliability of semiconductor devices.
5. Environmental Science: D-SIMS is used for analyzing pollutants in environmental samples, contributing to the monitoring of environmental pollution conditions.