Solid-state image sensor, manufacturing method for solid-state image sensor, and camera

Abstract

The solid-state image device in the present invention includes a plurality of light-receiving elements arranged in a light-receiving area, and a plurality of micro-lenses 7 corresponding to the light-receiving elements, and has a flattening film 8 formed on the plurality of the micro-lenses. At the center of the light-receiving area, micro-lenses 7 are placed in positions directly above the corresponding photodiodes 1, and placed in positions which are progressively offset from the positions directly above the corresponding photodiodes 1, towards the center of the light receiving area, as micro-lenses 7 are located farther from the center of the light-receiving area.

Description

technical field [0001] The present invention relates to a solid-state imaging device having microlenses on a plurality of light-receiving elements formed on a semiconductor substrate and a manufacturing method thereof. Background technique [0002] In recent years, while the number of pixels of solid-state imaging devices has increased, video cameras have also been miniaturized. [0003] In digital still cameras, camera-equipped mobile phones, and the like, the exit pupil distance has been shortened along with miniaturization of cameras. Here, the exit pupil refers to the virtual image of the lens (or diaphragm) viewed from the light receiving surface side, and the exit pupil distance refers to the distance between the light receiving surface and the lens (see Figure 18). [0004] Fig. 18 is a cross-sectional view of the camera portion of the mobile phone. A lens 110 is attached to a body 111 of the mobile phone, and a CCD image sensor 112 is provided inside the mobile pho...

AI Technical Summary

Problems solved by technology

[0007] However, according to the prior art described above, the reduction of the exit pupil distance has reached its limit in recent years for the thinning of video cameras for mobile phones and digital still cameras.

For example, with the structure shown in Fig. 1, if the exit pupil distance is further shortened, as shown in Fig. 2, light cannot be collected on the light receiving element, and shadows are generated due to insufficient sensitivity at the end of the light receiving surface.

That is to say, the closer to the end from the center of the image, the worse the sensitivity, and the darker the image is to the periphery, and the image quality deteriorates.

[0008] Furthermore, since the exit pupil distance is shortened, in the case of FIG. 2 , in order to form the microlenses at an appropriate position, the mask must be positioned with higher precision in the process of forming the microlenses. Positioning is difficult to achieve in both design and manufacture

[0009] And, although the solid-state imaging device of Japanese Unexamined Patent Publication No. 6-326284 can suppress the decrease in sensitivity when the aperture is opened wide, there is the same problem for shortening the exit pupil distance.

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