Solid-state imaging element, solid-state imaging device, and method for fabricating the same

A method for fabricating a solid-state imaging device comprising a plurality of solid-state imaging elements which are arranged in a two-dimensional plane,

• wherein each of the solid-state imaging elements has a photoelectric conversion element and an optical element which is formed on the photoelectric conversion element,
• the optical element has a refractive index periodic structure for a predetermined refractive index, the refractive index periodic structure being made up of at least two types of light-transparent materials with different refractive indices which are stacked in layers,
• the refractive index periodic structure has a periodic structure along a stacking direction of multiple layers and a periodic structure along an in-plane direction of concentric similar shapes, and
• the method includes a step of forming the optical element in a tube shape by creating, using lithography and etching, a central cavity and one or more concentric cavities around the central cavity inside the optical element by extending, in a direction vertical to the in-plane direction, a central opening and concentric similar-shaped openings in a horizontal plane.

A method for fabricating a solid-state imaging device comprising a plurality of solid-state imaging elements which are arranged in a two-dimensional plane,

• wherein each of the solid-state imaging elements has a photoelectric conversion element and an optical element which is formed on the photoelectric conversion element,
• the optical element has a refractive index periodic structure for a predetermined refractive index, the refractive index periodic structure being made up of at least two types of light-transparent materials with different refractive indices which are stacked in layers, the refractive index periodic structure has a periodic structure along a stacking direction of multiple layers and a periodic structure along an in-plane direction of concentric similar shapes,
• a vertical sectional profile of the periodic structure along the in-plane direction of the concentric similar shapes is a series of triangles, and
• the method includes a step of forming the optical element on a base by creating, using autocloning, the refractive index periodic structure in both the in-plane direction and the stacking direction, the base having the concentric similar shapes in the in-plane direction.