| 摘要 |
PROBLEM TO BE SOLVED: To form a fine pattern in a short time while keeping a surface clean, by forming a second film which covers a part of a first film and whose etching rate is faster than that of the first film, etching the second film wherein a pattern is formed in atmosphere, and bringing a product into contact with the first film. SOLUTION: When a PSG film 23 is etched by hydrofluoric acid, water is produced from the PSG film 23 as a reactive product. The produced water attains and attaches to an oxide film 22 and hydrofluoric acid solution of high concentration is produced as hydrofluoric acid constituting atmosphere dissolves. Therefore, an etching rate of the oxide film 22 increases in a region A alone in contact with hydrofluoric acid solution 25, a pattern is formed to the oxide film 22 and the width of a pattern is about 200Å. Therefore, a fine pattern can be formed to an oxide film in a short time while keeping a surface of a board and various formed films, etc., clean without increasing the number of processes.
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