Particle characteristics of 300-mm minienvironment (FOUP and LPU)

Abstract

We have clarified the particle characteristics of a front opening unified pod (FOUP) and a load port unit (LPU) experimentally. The FOUP and LPU are fundamental components in 300-mm minienvironment systems. Our experiments showed the following.• The particles per wafer pass (PWP) increases with the number of airborne particles outside the enclosure. • The particle characteristics of FOUP and LPU can be improved by reducing the FOUP door-opening speed. • The PWP of the wafer in the top slot is remarkably high. By optimizing the FOUP door-opening speed, we can achieve FOUP and LPU particle characteristics similar to those of a standard mechanical interface (SMIF) system.

Particle Dynamics in a Front-Opening Unified Pod/Load Port Unit Minienvironment in the Presence of a 300 mm Wafer in Various Positions

“…Kobayashi et al (2000) performed PWP testing on particles with diameters ≥0.12 µm, for wafers in the FOUP during the opening of the FOUP door. They reported that the PWP value of the top wafer (wafer 25) is the highest.…”