Simultaneous Observation of Molecular Contamination Behavior in Semiconductor Clean room Using Quartz Crystal Microbalance

Abstract

To search the cause and mechanism of the molecular contamination trouble that sometimes occurs in the semiconductor manufacturing, we developed a quartz crystal microbalance (QCM) molecular contamination monitoring system that is able to carry out two-dimensional simultaneous observation with a high sensitivity. As the result of long-term simultaneous observation of different QCM sensor surface materials in an operating semiconductor clean room, it has been understood that QCM can monitor the changes in the molecular contamination environment very sensitively. We observed for the first time the emission phenomenon of molecular contamination that is discharged from equipments synchronizing with the process sequence by observation of the QCM system. Moreover, the phenomena of NOx in a clean room air of less than 100 ppb promoting the adsorption of the molecular contaminants were observed. The multipoint continuous monitoring of the clean room atmosphere by the QCM system was shown to be very effective in the clarification of the cause of molecular contamination trouble.