ABSTRACT
I. Reclamation Technology for Developer (TMAH) Waste . . . . . . . . . . . . . . . . . . . . . 315
A. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
B. Developer Reclamation System and Equipment . . . . . . . . . . . . . . . . . . . . . . . . 316
C. Experimental and Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
D. Commercial Application and Future Challenges . . . . . . . . . . . . . . . . . . . . . . . 321
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
II. Reclamation Technology for HF Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
A. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
B. HF Waste Treatment using Calcite Method . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
C. HF Waste Treatment using Crystallization Method . . . . . . . . . . . . . . . . . . . . . 326
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
High-purity metal-free tetramethylammonium hydroxide (TMAH) aqueous solution is widely used
as a developer in manufacturing lines of semiconductor device and liquid crystal display (LCD).
TMAH is often chosen as a preferable option because it helps prevent metal contamination,
which is one of the major causes of yield deterioration. TMAH is produced by electrolyzing tetra-
methylammonium (TMA) salt through cation exchange membrane (CEM) [1,2]. Its purity has
been constantly improved along with advances in geometry, density, and functionality of semicon-
ductor device. As Si wafer for semiconductor device and mother glass for LCD increase in size and
the developer is expected to feature higher purity, costs relating to the developer are increasing. Costs
to treat TMAH waste are also high as TMAH is an organic alkali that requires a specific treatment.
