Energy Dispersive X-ray Spectroscopy (EDS/EDX) is an analytical technique that identifies the elemental composition of materials by detecting characteristic X-rays emitted when a specimen is bombarded with an electron beam — integrated into SEMs and TEMs as the most accessible and widely used chemical analysis tool in semiconductor failure analysis and process development.

What Is EDS?

• Definition: When a high-energy electron beam strikes a sample, it ejects inner-shell electrons from atoms. As outer-shell electrons fill the vacancy, characteristic X-rays are emitted with energies unique to each element. An energy-dispersive detector measures these X-ray energies and intensities to identify and quantify the elements present.
• Range: Detects elements from beryllium (Z=4) to uranium (Z=92) — covering all elements relevant to semiconductor manufacturing.
• Detection Limit: Typically 0.1-1 atomic percent — sufficient for major and minor constituent identification but not trace analysis.

Why EDS Matters

• Contamination Identification: When a defect or contamination is found on a wafer, EDS immediately identifies which elements are present — pointing to the contamination source.
• Interface Analysis: Composition profiling across interfaces (metal/dielectric, gate stack, barrier layers) reveals interdiffusion, reaction products, and composition gradients.
• Process Verification: Confirms correct material deposition — verifies that the intended elements are present in the right proportions.
• Failure Analysis: Identifies anomalous materials at failure sites — corrosion products, void fillers, foreign materials, and contamination.

EDS Capabilities

• Point Analysis: Focus beam on a specific location — identify all elements present.
• Line Scan: Sweep beam across a line — generate composition profiles showing how elements vary with position.
• Element Mapping: Raster beam across an area — create color-coded maps showing spatial distribution of each element.
• Quantitative Analysis: Calculate atomic and weight percentages of each element using ZAF or Phi-Rho-Z corrections.

EDS Specifications

EDS vs. Other Analytical Techniques

EDS is the first-line chemical analysis tool in semiconductor failure analysis — providing rapid, non-destructive elemental identification that guides every investigation from contamination source identification to interface characterization and process verification.