Hydrogen Fluoride Consumption Reduced by 87%
Samsung Electronics has recently developed a system for reusing a high-concentration hydrogen fluoride cleaning solution and is currently testing it on its semiconductor production lines.
The system is to reuse hydrofluoric acid (liquefied hydrogen fluoride) used for semiconductor cleaning. High-purity hydrofluoric acid is one of the three semiconductor materials on which the Japanese government imposed export restrictions in July 2019. In the system, the hydrogen fluoride cleaning solution, which has been disposable, is collected through internal circulation for reuse.
Hydrogen fluoride is used for wafer cleaning and etching. Specifically, hydrofluoric acid, which is liquid hydrogen fluoride, is for wafer cleaning and gaseous hydrogen fluoride is for etching. The Japanese companies including Stella Chemifa and Morita Chemical Industries currently supply more than 90 percent of the high-purity hydrogen fluoride used in semiconductor production processes worldwide.
The system developed by Samsung Electronics is characterized by reusing hydrofluoric acid in the wafer back surface cleaning process, that is, removing metallic contaminants from the wafer surface after the wiring process. Samsung Electronics conducted a series of tests and succeeded in ensuring a stable quality for up to 1,500 products while reutilizing approximately 80 percent of the hydrogen fluoride-mixed solution.
Samsung Electronics may apply the system to the entire production facilities depending on the result of the test. According to the company, its hydrogen fluoride consumption can be reduced by 87 percent in that case.