Evolved Gas Analysis (EGA)
EGA is a method for monitoring small amounts of gas molecules evolved from samples when heated above room temperature. This analysis can be primarily used to determine: (1) composition of evolved gases (2) concentration of evolved gases (3) evolution profile with respect to heating temperature. This information is vital for quality control, failure analysis or establishing protocol for a manufacturing process.
At EAG Laboratories, we are successfully using evolved gas analysis for a variety of samples providing solutions to different industries including semiconductors, aerospace & defense, coatings & adhesives, energy storage & batteries, and medical devices.
What is Evolved Gas Analysis (EGA)?
Principle:
Gas molecules evolve from a surface/solids/powders when heated above room temperature. In EGA method, sample is evacuated to minimize the gas from surroundings. When the vacuum reaches to a background level, the sample is heated and evolved gases are then expanded to mass spectrometer volume. Using a thoria coated iridium filament, gases are ionized to facilitate mass separation using a quadrupole mass analyzer. Positive ion currents are measured using an electron multiplier, providing intensity of each gas released from sample.
Common applications:
Semi-quantitative
- Comparative study: Good vs. Bad samples
- Wafer level failure analysis for hermetic electronic components
- Confirming quality of UHV grade cleaning for SS parts
- Comparative study for Gas release @ specific temp
- Direct Gas analysis
- Outgassing from gas tight seals in hermetic devices
- Efficacy of getter inside a vacuum cavity
- Outgassing rates (moles/cm2/sec)
- Gas released in cavity after outgassing (piercing in vacuum)
Qualitative scan
- Mass scanning while ramping temperature
- 3-D plotting of Temperature-vs-mass-vs-signal
- Comparative scan: Good vs. Bad samples
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3-D representation showing mass release signals for different masses with respect to outgassing temperature. The comparison between chemically treated and untreated Si wafer clearly shows the effect of cleaning treatment. Higher release for mass 44 (e.g., CO2) and mass 28 (e.g., N2/CO) is observed for untreated sample.