| 摘要 |
PURPOSE:To provide a method for forming a relief type fine grating which consists of recessed and projecting parts formed at cyclic intervals on the surface of an optical functional element using a compound semiconductor. CONSTITUTION:The method for forming a fine grating comprises the following four stages: (1) the first stage for placing a compound semiconductor in a vessel which can be evacuated to vacuum; (2) the second stage for forming the mask layer 12 consisting of a monoatomic or several-atomic layer on the surface of the compound semiconductor substrate 11; (3) the third stage for irradiating with the reactive gas 14 to or allowing it to contact with the surface of the masked compound semiconductor substrate 11 and at the same time for irradiating the surface of the masked substrate 11 with electron beams 13; (4) the fourth stage for allowing the etching of the electron beam irradiated region 15 with the reactive gas 14 to proceed after changing the region to be irradiated with the electron beam 13 from the region 15 to the adjacent region. Further, by repeating the stages (3) and (4) in a spatially successive manner, the fine grating can be formed in a stepwise worked shape. |
