摘要 |
PROBLEM TO BE SOLVED: To provide a method of reducing a part which is not etched when an etching film is formed into an extremely fine pattern by patterning through wet etching. SOLUTION: In a process shown in Figure 1 (a), a silicon oxide film 12 is formed on a silicon substrate 11. Then a resist mask 13 is formed on the silicon oxide film 12. At this point, as shown in Figure 1 (a), an opening region 14 of small dimensions and an opening region 15 of comparatively large dimensions residue on the resist mask 13 at the same time. Next, in a process shown in Figure 1 (b), liquid 16 (pure water) soluble in etchant in a wet etching process which is stated later and forms a small contact angle with the resist mask 13 is applied on the surface of the wafer W. Then, in a process shown in Figure 1 (c), while the liquid 16 as pure water keeps staying on the resist mask 13 and the silicon oxide film 12 (water applied in layer), the substrate is dipped into a buffer hydrofluoric acid water solution (a mixture of HF/H2 O and HF/NH4 F).
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