Solid-state imaging device, fabrication method thereof, imaging apparatus, and fabrication method of anti-reflection structure
A fabrication method of an anti-reflection structure includes the steps of: forming a resin film having micro-particles dispersed therein on a surface of a substrate; forming a protrusion dummy pattern on the resin film by etching the resin film using the micro-particles in the resin film as a mask while gradually etching the micro-particles; and forming a protrusion pattern on the surface of the substrate by etching back the surface of the substrate together with the resin film having the protrusion dummy pattern formed thereon, and transferring a surface shape of the protrusion dummy pattern formed on a surface of the resin film to the surface of the substrate.
1. A fabrication method of an anti-reflection structure, the method comprising the steps of:
providing a resin film having micro-particles dispersed therein on a surface of a substrate;
forming a dummy protrusion pattern on a surface of the resin film by etching the resin film using the micro-particles in the resin film as a mask while gradually etching the micro-particles; and
forming a protrusion pattern on the surface of the substrate by etching back the surface of the substrate together with the resin film having the protrusion dummy pattern formed thereon, thereby transferring a surface shape of the dummy protrusion pattern formed on the surface of the resin film to the surface of the substrate and eliminating the resin film, the resulting protrusions being tapering in cross-section from a relatively wide base to a relatively narrow end, the resulting protrusions having a distribution pitch and an aspect ratio of height to base diameter effective to suppress reflection of light and provide the anti-reflection structure.
2. The fabrication method of an anti-reflection structure according to claim 1 , wherein the resin film having the micro-particles dispersed therein is formed by a coating method.
3. The fabrication method of an anti-reflection structure according to claim 1 or 2 , wherein the micro-particles are made from metal oxides or a phthalocyanine compound; and the resin film is selected from a group consisting of a novolac-based resin, a styrene-based resin, an acrylic resin, a polysiloxane-based resin, and a polyimide-based resin.
4. The fabrication method of an anti-reflection structure according to claim 1 or 2 , wherein the resin film contains a heat curing agent.
5. The method of claim 1 , wherein the resulting protrusions have an aspect ratio of 4 or less.
6. The method of claim 5 , wherein the resulting protrusions have an aspect ration of 1 to 2, inclusive, and a distribution pitch of 100 nm to 200 nm inclusive.
7. The method of claim 5 , wherein the resulting protrusions have an aspect ratio of 2.5 or less.