Ryota Sasajima

Adsorption of Dibutyl Phthalate and Dioctyl Phthalate on Si Substrate

The behaviors of organic compounds such as dibutyl phthalate (DBP) or dioctyl phthalate (DOP) on a Si substrate are investigated by gas chromatograph and mass analysis (GC–MS). DBP or DOP source is set in a chemically clean booth, and organic amount is measured in air and on the substrate. At various concentrations of DBP or DOP, organic adsorption amount is measured and this amount is expressed by the Langmuir equation. In a mixed-gas atmosphere, the amounts of DBP and DOP are measured and it is clear that DBP concentration decreases when the total organic amount exceeds the saturated adsorption amount on the substrate. This phenomenon is understood as the replacement of DBP by DOP. In this paper, we describe the adsorption amount quantitatively in individual atmosphere of DBP or DOP and a mixed-gas atmosphere.

Slip Generation in Si Wafers due to Friction-Induced Stress and Its Suppression Technique

Slip-free 300 mm wafers annealed at temperatures higher than 1000°C have been investigated. It has been found that friction-related stress must be introduced to explain slip generation experimentally in addition to gravitationally induced bending stress, compressive stress and thermally induced stress. Slip-free 300 mm wafers annealed at 1350°C are obtained by appropriately controlling the surface roughness of the supporting disk.