Clean Room Process Compatibility of Polymeric Materials for the Semiconductor Industry

Abstract

A protocol has been developed for the process compatibility of materials for the Semiconductor industry. The process compatibility is assessed by the release of organic compounds, ions, elements, and total oxidizable carbon (TOC) considered undesirable as they damage the wafers and adversely affect their manufacturing yields. The total mass of undesirable organic compounds outgassed per unit surface area of the material under normal operating conditions of the clean rooms is expressed as the outgassing parameter (OP). The total mass of undesirable ions, elements, and TOC leached per unit surface area of the material by ultrapure water (UPW) and ozonated UPW is expressed as the leaching parameter (LP). The total mass of undesirable elements extracted per unit surface area of the material by cleaning solutions of chemicals is expressed as the extraction parameter (EP). The results of the study show that the OP, LP, and EP values of the highly fire resistant materials for the clean rooms of the Semiconductor industry (CPVC, ECTFE, and PVDF) are lower than the values for the ordinary materials (PP, FRPP, and PVC). Ordinary materials have been used in clean rooms for many years without any major problems due to process compatibility and thus the highly fire resistant materials are also process compatible. All these materials are process compatible beacuse low boiling point monomers that are weakly bonded and solvents trapped in the polymer matrix are outgassed. In addition, leaching and extraction occur via weak processes of hydrolysis, breaking of bonds, dissolving and extraction of additives, surface attack by chemicals, and penetration of the material matrix through spaces in the chains.