Solid-state imaging device and camera

Abstract

A solid-state imaging device 101 is composed of a transparent film 204, a color filter 205, a planarizing film 207, and a plurality of microlenses 208 that are sequentially formed on a semiconductor substrate 201. A photodiode 202 is formed in a surface of the semiconductor substrate 201 that is closer to the transparent film 204. A light shielding film 203 is formed in a surface of the transparent film 204 that is closer to the semiconductor substrate 201. Color filters 205 respectively corresponding to two adjacent pixels are partitioned by a light shielding wall 206. The light shielding wall 206 is a λ/4 multilayer film that reflects visible light.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings those illustrate a specific embodiments of the invention.

In the drawings:

FIG. 1 is a block diagram showing a structure of a solid-state imaging device according to a conventional art;

FIG. 2 is a sectional view showing a structure of pixels 501 of the solid-state imaging device according to the conventional art;

FIG. 3 is a sectional view showing a structure of a digital camera according to an embodiment;

FIG. 4 is a sectional view showing a pixel of a solid-state imaging device 101;

FIG. 5A shows a structure of one of the color filters 205 that transmits blue light (hereinafter “blue filter”), FIG. 5B shows a structure of one of the color filters 205 that transmits red light (hereinafter “red filter”), FIG. 5C shows a structure of one of the color filters 205 that transmits green light (hereinafter “green filter”), and FIG. 5D shows a structure of the light shielding wall 206; and

FIG. 6A to FIG. 6D show spectral characteristics of the red filter, the green filter, the blue filter, and the light shielding wall 206, respectively.

Claims

1. A solid-state imaging device that includes two-dimensionally arrayed pixels and images in color, the solid-state imaging device comprising: a plurality of color filters each operable to transmit light of a wavelength predetermined for each pixel; anda light shielding wall operable to partition the color filters for each pixel, whereinthe light shielding wall includes a multilayer film and reflects visible light, the multilayer film being composed of alternately laminated two types of dielectric layers each having a different refractive index and a same optical thickness.

2. The solid-state imaging device of claim 1, wherein each of the color filters is a multilayer interference filter.

3. The solid-state imaging device of claim 2, wherein the light shielding wall and at least one of the color filters have a same number of layers.

4. The solid-state imaging device of claim 2, wherein the light shielding wall and the color filters are made from a same dielectric material.

5. The solid-state imaging device of claim 4, wherein the multilayer interference filters that constitute the color filters are composed of two λ/4 multilayer films with a spacer layer sandwiched therebetween, andeach dielectric layer that constitutes the light shielding wall and each dielectric layer of the λ/4 multilayer films that constitute the color filters have a same optical thickness.

6. The solid-state imaging device of claim 1, wherein the light shielding wall is a multilayer interference filter composed of two λ/4 multilayer films with a spacer layer sandwiched therebetween.

7. The solid-state imaging device of claim 1, wherein a multilayer interference filter that constitutes each color filter is composed of two λ/4 multilayer films with a spacer layer sandwiched therebetween, anda film thickness of the spacer layer differs according to a color of light transmitted by the color filter.

8. The solid-state imaging device of claim 7, wherein the light shielding wall is composed of two λ/4 multilayer films with a spacer layer sandwiched therebetween, andthe spacer layer of the color filter has an optical thickness different from an optical thickness of the spacer layer of the light shielding wall.

9. A camera having a solid-state imaging device, the solid-state imaging device comprising: two-dimensionally arrayed pixels;a plurality of color filters each operable to transmit light of a wavelength predetermined for each pixel; anda light shielding wall operable to partition the color filters for each pixel, whereinthe light shielding wall includes a multilayer film and reflects visible light, the multilayer film being composed of alternately laminated two types of dielectric layers each having a different refractive index and a same optical thickness.