Solid-state imaging device, method for manufacturing the same, and camera using the same

Abstract

In order to implement a solid-state imaging device with high photo-sensitivity that includes a light collecting part which can reduce undesired variations during manufacture and which has high light collection efficiency, the solid-state imaging device includes: a photodiode ( 8 ) which converts incident light ( 13 ) into electric charges; a convex lens layer ( 15 ) which is formed above the photodiode ( 8 ) and through which the incident light is transmitted; and a concavo-convex lens layer ( 11 ) which is formed on and around the lens layer ( 15 ) and which collects the incident light and outputs the incident light to the lens layer ( 15 ). A refractive index of the lens layer ( 15 ) is greater than a refractive index of the lens layer ( 11 ). A thickness and a width of the lens layer ( 15 ) are set to achieve a predetermined focal length for light of a predetermined wavelength range. The lens layer (15) is made of one of a BPSG film, a TEOS film, a benzocyclobuthane and polyimide based resin.

Description

technical field [0001] The present invention relates to a solid-state imaging device mounted on a digital camera or the like. Background technique [0002] Regarding the solid-state imaging device, various technical proposals have been proposed (for example, refer to Patent Document 1). [0003] FIG. 1 illustrates a conventional solid-state imaging device. In this solid-state imaging device 110 , unit pixels 1 are arranged two-dimensionally, each row is selected by a vertical shift register 2 , the row signal is selected by a horizontal shift register 3 , and the color signal of each pixel is output from an output amplifier 4 . The peripheral drive circuit 5 operates the vertical shift register 2 , the horizontal shift register 3 and the output amplifier 4 . [0004] FIG. 2 is a cross-sectional view of a pixel portion of a conventional solid-state imaging device. In the solid-state imaging device 100 (only three pixels are shown in FIG. 2 ), a P-type layer 7 is formed on ...

AI Technical Summary

Problems solved by technology

Therefore, there is a problem that, in the structure of the conventional solid-state imaging device, the light-gathering efficiency of the pixels near the periphery decreases, resulting in deterioration of image quality.

In this case, it is difficult to control the formation position with high precision in the structure using the conventional convex microlens

[0011] In addition, in the disclosed method, a method of concentrating light through a transmission layer with a concentric refractive index periodic structure has also been proposed, but due to the existing technology, it is impossible to stably form a transmission layer with a sufficient film thickness. Layer, so the optical path length cannot be fully guaranteed, so the incident light cannot be sufficiently concentrated

In order to increase the light-gathering efficiency, it is necessary to ensure a sufficient film thickness of the transmissive layer, but this is difficult to achieve with current manufacturing methods and materials

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