Yoshimi Shiramizu

Requirements for contamination control in the G-bit era

In future G-bit DRAM fabrication, the particle density on wafers will be seriously increased. This is because the deposition velocity of particles smaller than 0.1/spl mu/m drastically increases, and is further accelerated by the electrostatic potential of wafers. The lower limit of the conventional cleanroom cleanliness will be class 0.1-1 level, by dust generation from people. This fact leads us to the minienvironment fab system with automated I/O. In minienvironment systems, however, organic contamination will be a serious problem. Box material, plasticizer and anti-oxidizing agent must be reexamined from the viewpoint of organic contamination control.