ExpertTM is designed for the integration with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) base on the experience of ultratrace metal analysis by ICP-MS.
Analysis of metallic impurities in Si wafer is one of important items in semiconductor manufacturing. The concentration of metallic impurities to be controlled has been lower and lower as the integration has been higher. Total Reflection X-Ray fluorescence (TRXRF) has been used in a production line (FAB) because of its non-destructive technique. However, the detection limit of TRXRF could not satisfy the requirement, and VPD (Vapor Phase Decomposition) technique was developed as a sample pre-concentration method. As a result, the detection limit was improved around two orders of magnitude, but TRXRF is no longer a non-destructive technique. In addition, the chemical solution prepared by VPD can be directly analyzed by ICP-MS with much lower detection limit including lighter masses such as Li, Na and Mg. Consequently, ICP-MS with VPD becomes a common technique to control metallic impurities in Si wafer.
There are several VPD equipment in the market, but they are developed for preparation of TRXRF and not designed for ICP-MS analysis.