Patent ID: 8361339
Filing Date: 2013-01-29
Classification: B81C,C03C,G02B,Y10T

Abstract:
1. A method for forming an antireflection structure in which plural projections are arranged on a substrate, comprising the steps of: forming a base layer on a substrate, forming a particle-trap layer on said base layer, forming, on said particle-trap layer, a multi-particle layer in which particles having a mean particle size of 20 to 1000 nm are arranged in one or more layers, sinking the particles positioned at the bottom of said multi-particle layer into the particle-trap layer, removing the particles in said multi-particle layer except the particles positioned at the bottom, removing said particle-trap layer with holding the particles positioned at the bottom on the base layer, and performing an etching process in which said base layer is subjected to reactive ion etching while the particles remaining on said base layer are used as a mask to form projections, under the conditions that the etching rate ratio of said base layer to said particles is more than 1 but not more than 5 and that the process is stopped before the particles disappear by etching where 80% or more of the particles remaining after the etching process have a relative volume of more than 0% but not more than 25% based on the volume of those before the etching process, wherein said particles and said base layer are simultaneously etched to form an antireflection structure having a plurality of projections.