STUDY ON ADSORPTION BEHAVIOR OF ORGANIC CONTAMINATIONS ON SILICON SURFACE BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

We successfully revealed the adsorption behavior of actual organic con taminations on a Si wafer surface using a gas chromatograph/mass spect rometer system with a quartz heat-desorption chamber and a two-step co ncentration trap. Antioxidants contained in the wafer case material an d a monomer and an oligomer from the plastic vessel material used in t he production process were confirmed to contaminate the surface oi the Si wafer. Organic materials in the atmosphere, such as organic solven ts and plasticizers, were also observed to adsorb on the surface durin g an exposure to a laboratory atmosphere for a fen: hours. The results suggest that completely surface-cleaned Si wafers should be stored in a stocker in which the amount of organic species in the atmosphere is well controlled.