Abstract
It is possible to etch only to the part where the ion beam was irradiated selectively by irradiating the focused ion beam to quartz, and developing it with the buffered hydrogen fluoride afterwards. The etching speed in this case is about two digits earlier than the etching speed by the FIB processing. And, it has been understood to be able to process the nano order. Then, this technique was used, the mask was not used, and the line and the space pattern were made.