| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for etching a substrate that allows upper and outer surfaces of a three-dimensional structure, such as an optical disc and substrate, to be uniformly etched. <P>SOLUTION: An etching method comprises steps of: placing a substrate 2 having a ground outer surface 2b in an etching gas atmosphere; inputting light with a tilt angle onto upper surface 2a of the substrate 2 through a prism 3, the light having a wavelength greater than the absorption edge wavelength of gas molecules constituting the etching gas; propagating the light to the outer surface 2b while causing the light to reflect between the upper surface 2a and lower surface 2c of the substrate 2; dissociating the etching gas using the propagated light outputted from the inside of the substrate 2 to the outside through the outer surface 2b to etch irregularities formed on the outer surface 2b; generating near-field light based on the propagated light at least at a corner in the irregularities; and dissociating the etching gas using the near-field light to etch the irregularities. <P>COPYRIGHT: (C)2012,JPO&INPIT |
