OPTICAL ELEMENT AND METHOD OF MANUFACTURING OPTICAL ELEMENT

• US 20070201135A1
• Filed: 02/21/2007
• Published: 08/30/2007
• Est. Priority Date: 02/28/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Nakai, Noriyuki, Terada, Junji, Arai, Kazuhiro, Sakamoto, Jun-ichi
• Granted Patent: US 7,929,209 B2
• Time in Patent Office: Days
• US Class Current: 359/486
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 1/002 made of materials engineered to provide properties not available in nature, e.g. metamaterials
• CPC Class Codes: G02B 27/42 Diffraction optics , i.e. systems including a diffractive element being designed for providing a diffractive effectG02B27/60 takes precedence
• CPC Class Codes: G02B 27/4261 having a diffractive element with major polarization dependent properties
• CPC Class Codes: G02B 5/1809 with pitch less than or comparable to the wavelength
• CPC Class Codes: G02B 6/126 using polarisation effects G02B6/1226 takes precedence
• CPC Class Codes: G02B 6/136 by etching

Abstract

The present invention provides an optical element having a three-dimensional structure which can function in a visible range and can improve adherence at a structural interface of the element, and a method of manufacturing the optical element. The optical element including a substrate and at least a first layer and a second layer on the substrate is manufactured such that each of the first layer and the second layer has a repetition structure of spaces and structural parts at a pitch equal to or less than a wavelength of visible light, and at an interface between the first layer and the second layer, overlapped structures are provided in which the repetition structure of the first layer and the repetition structure of the second layer overlap in a stack direction of the layers.

Claims

1. An optical element comprising:

a substrate, and

a first layer and a second layer formed on the substrate,

wherein each of the first layer and the second layer comprises a repetition structure of spaces and structural parts at a pitch equal to or less than a wavelength of visible light in a vertical direction to a stack direction of the layers, and

wherein, the repetition structure of the first layer and the repetition structure of the second layer overlap at an interface between the first layer and the second layer, in the stack direction of the layers.

2. An optical element according to claim 1, further comprising a plurality of layers between the substrate and the first layer, wherein the first layer is formed of an i-th layer and the second layer is formed of an (i+1)th layer counting from the substrate.

3. An optical element according to claim 1, wherein, the repetition structure of the first layer and the repetition structure of the second layer overlap in a range of 3 nm or more and 20 nm or less.

4. An optical element according to claim 1, wherein each repetition structure of the first layer and the second layer comprises any one of a line-and-space structure, a structure with holes, and a structure with dots.

5. An optical element according to claim 1, wherein the pitch equal to or less than the wavelength of visible light in the first layer and the second layer is 10 nm or more and 200 nm or less.

6. An optical element according to claim 1, wherein the repetition structure of the first layer and the repetition structure of the second layer are formed of the same material.

7. An optical element according to claim 1, wherein the repetition structure of the first layer and the repetition structure of the second layer are formed of a dielectric material.

8. A method of manufacturing an optical element comprising a substrate, and a first layer and a second layer formed on the substrate, the method comprising the steps of:

forming the first layer on the substrate;

processing in the first layer a repetition structure comprised of spaces and structural parts, having a pitch equal to or less than a wavelength of visible light;

filling the spaces in the repetition structure with a material of a sacrificial layer;

etching the sacrificial layer to expose an upper portion of the repetition structure from the sacrificial layer;

forming the second layer on the repetition structure and the sacrificial layer;

processing in the second layer a repetition structure comprised of spaces and structural parts, having a pitch equal to or less than a wavelength of visible light; and

removing the sacrificial layer.

9. A method of manufacturing an optical element according to claim 8, wherein in the step of exposing the upper portion of the repetition structure from the sacrificial layer, side surfaces of the repetition structure are exposed in a range of 3 nm or more and 20 nm or less from an upper surface of the repetition structure.