Trace‐Impurity Behavior of Semiconductor Ultra‐High‐Purity Hydrogen: Comparison of Gaseous and Liquefied Hydrogen Feedstocks After Getter and Cryogenic Purification Using Multi‐Channel Gas Chromatography With Plasma Emission Detection

ABSTRACT

As semiconductor manufacturing advances, ultra‐high‐purity hydrogen quality has become important for process reproducibility, equipment reliability, and contamination control. The emerging introduction of liquefied hydrogen alongside conventional gaseous hydrogen requires analytical criteria that account for feedstock‐dependent behavior after purification. An operating semiconductor hydrogen supply system was used as a field platform to compare argon, nitrogen, carbon monoxide, carbon dioxide, methane, and non‐methane hydrocarbons after getter and cryogenic purification using multi‐channel gas chromatography with plasma emission detection. Raw liquefied hydrogen showed lower impurity levels and narrower variability than raw gaseous hydrogen in the investigated deliveries, whereas gaseous hydrogen showed greater variation, particularly for argon, nitrogen, and methane. At the final supply line, most target impurities in liquefied‐hydrogen‐derived product were below the method detection limits, whereas residual signals in gaseous‐hydrogen‐derived product reflected both feedstock characteristics and purification pathway. The main contribution is a process‐resolved interpretation framework linking raw‐feed measurements, individual purifier outlets, and final endpoint signals. These results indicate that interpretation criteria derived from gaseous‐hydrogen operation may require verification before application to liquefied‐hydrogen‐based systems, especially when vaporization history and purification pathway differ.