Tetramethylammonium hydroxide (TMAH) is widely used as a photoresist developer in semiconductor manufacturing processes. In photoresist developer solutions, trace levels of cations such as Na⁺, NH₄⁺, and K⁺ must be carefully controlled. In this application, standard solutions of TMAH, Na⁺, NH₄⁺, and K⁺ were analyzed using a cation chromatography column, IC YS-50. There was a good linearity in the 1 to 100 mg/L range for TMAH.

Sample: 10 µL

1. 1.Na⁺ 2 mg/L
2. 2.NH₄⁺ 2mg/L
3. 3.K⁺ 2 mg/L
4. 4.Tetramethylammonium hydroxide (TMAH) 50 mg/L