LIQUID FOR RECOVERING NICKEL FROM SILICON SUBSTRATE AND NICKEL RECOVERY PROCESS

摘要

PROBLEM TO BE SOLVED: To easily recover nickel with a single recovery treatment run. SOLUTION: This nickel recovering liquid used for dissolving nickel existing on the surface of a silicon substrate and in its surface oxide film and recovering the dissolved nickel, contains hydrochloric acid, hydrofluoric acid and nitric acid so that the total volume of hydrofluoric acid and nitric acid is larger than the volume of hydrochloric acid, and is prepared by mixing 20 wt.% hydrochloric acid, 38 wt.% hydrofluoric acid and 68 wt.% nitric acid together in a mixing ratio of (hydrochloric acid):(hydrofluoric acid):(nitric acid) of 1:1:2 to 1:1:4.