Patent ID: 9701927
Date: 2017-07-11
CPC Classifications: B08B,C11D,G02B

Claim:
1. A cleaning method for cleaning a concavity, the concavity being a region between adjacent two of a plurality of convexities of an antireflective structure, the antireflective structure being transparent, the antireflective structure having the plurality of convexities on one surface of the antireflective structure, the plurality of convexities being formed at a period equal to or shorter than a wavelength in a visible light range, the antireflective structure preventing, at the one surface, reflection of light entering the one surface, the cleaning method comprising: using a cleaning solution having a pH of 10.00 or more, the cleaning solution including a buffer, wherein a height of each of the plurality of convexities is 100 nm or more and 600 nm or less, and a maximum value of a width of a bottom surface of the plurality of convexities, when looked at in a plan view, is 100 nm or more and 600 nm or less.