Analysis of trace impurities in neon by a customized gas chromatography

• Trace impurities in high-purity neon were analyzed with a customized GC system.
• Trace gases in neon analyzed by a customized GC system.
• He was analyzed in Ne with high precision using an injection pressurized Ne-TCD.

Excimer lasers, widely used in the semiconductor industry, are crucial for analyzing the purity of premix laser gases for the purpose of controlling stable laser output power. In this study, we designed a system for analyzing impurities in pure neon (Ne) base gas by customized GC. Impurities in pure neon (H2 and He), which cannot be analyzed at the sub-μmol/mol level using commercial GC detectors, were analyzed by a customized pulsed-discharge Ne ionization detector (PDNeD) and a pressurized injection thermal conductivity detector using Ne as the carrier gas (Pres. Inj. Ne-TCD). From the results, trace species in Ne were identified with the following detection limits: H2, 0.378 μmol/mol; O2, 0.119 μmol/mol; CH4, 0.880 μmol/mol; CO, 0.263 μmol/mol; CO2, 0.162 μmol/mol (PDNeD); and He, 0.190 μmol/mol (Pres. Inj. Ne-TCD). This PDNeD and pressurized injection Ne-TCD technique thus developed permit the quantification of trace impurities present in high-purity Ne.