Solid-state imaging device and method of manufacturing the same

1. A solid-state imaging device comprising:

a pixel region in which a plurality of pixels are disposed in a matrix above a semiconductor substrate; and

a peripheral region in which a multilayer interconnect structure for driving the plurality of pixels is formed, the peripheral region being peripheral to the pixel region in a plan view of the semiconductor substrate,

wherein the pixel region includes:

a charge accumulation and diffusion layer in the semiconductor substrate;

a plurality of pixel plugs formed above and electrically connected to the charge accumulation and diffusion layer, the plurality of pixel plugs respectively corresponding to the plurality of pixels;

a plurality of lower pixel electrodes formed on and electrically connected to the plurality of pixel plugs, respectively, the plurality of lower pixel electrodes respectively corresponding to the plurality of pixels;

a photoelectric conversion film formed on and electrically connected to the plurality of lower pixel electrodes; and

an upper pixel electrode formed on and electrically connected to the photoelectric conversion film, and

a top surface of an interconnect formed in an uppermost layer of the multilayer interconnect structure disposed in the peripheral region is above a bottom surface of the photoelectric conversion film.

2. The solid-state imaging device according to claim 1 ,

wherein the interconnect formed in the uppermost layer includes power supply line for supplying a power supply voltage to a circuit and a pad for wire bonding.

3. The solid-state imaging device according to claim 2 ,

wherein the power supply line, the pad, and a light shielding film for partially shielding the plurality of pixels have a same film thickness.

4. The solid-state imaging device according to claim 2 ,

wherein the power supply line, the pad, and a light shielding film for partially shielding the plurality of pixels include a same material.

5. The solid-state imaging device according to claim 4 ,

wherein the material included in the power supply line, the pad, and the light shielding film contains Al.

6. The solid-state imaging device according to claim 3 ,

wherein bottom surfaces of the power supply line and the pad are below a bottom surface of the light shielding film.

7. The solid-state imaging device according to claim 1 ,

wherein the multilayer interconnect structure contains Cu.

8. The solid-state imaging device according to claim 1 ,

wherein the plurality of lower pixel electrodes contain Ti or a chemical compound of Ti.

9. The solid-state imaging device according to claim 1 ,

wherein the plurality of pixel plugs contain Cu.

10. The solid-state imaging device according to claim 1 ,

wherein ring-shaped pattern is also disposed above an end portion of the upper pixel electrode to surround the pixel region in the plan view of the semiconductor substrate.

11. The solid-state imaging device according to claim 1 , further comprising

a protective film on the upper pixel electrode, for protecting the upper pixel electrode and the photoelectric conversion film,

wherein an end face of the upper pixel electrode is on a same plane with an end face of the protective film, and

the end face of the upper pixel electrode and the end face of the protective film form an angle of 45 degrees or more with a surface of the semiconductor substrate.

12. The solid-state imaging device according to claim 1 ,

wherein at an end portion of the photoelectric conversion film, the photoelectric conversion film continuously becomes thinner toward a periphery.

13. The solid-state imaging device according to claim 1 ,

wherein in the plan view of the semiconductor substrate, the upper pixel electrode is formed to cover the plurality of lower pixel electrodes.

14. A method of manufacturing a solid-state imaging device, the method comprising:

forming a charge accumulation and diffusion layer in a semiconductor substrate in a pixel region in which a plurality of pixels are disposed in a matrix above the semiconductor substrate;

forming a pixel plug to be positioned above and electrically connected to the charge accumulation and diffusion layer;

forming, in the following sequence, a lower pixel electrode, a photoelectric conversion film, and an upper pixel electrode in a stack, to be positioned above and electrically connected to the pixel plug; and

after forming the photoelectric conversion film, forming an interconnect in an uppermost layer of a multilayer interconnect structure so that a top surface of the interconnect is above a bottom surface of the photoelectric conversion film, the multilayer interconnect structure being disposed in a peripheral region peripheral to the pixel region in a plan view of the semiconductor substrate.

15. The method of manufacturing a solid-state imaging device according to claim 14 ,

wherein in the forming of the photoelectric conversion film, the photoelectric conversion film is formed by a shadow mask method, and

in each process subsequent to the forming of the photoelectric conversion film, dry etching and ashing are performed at a substrate temperature of 200° C. or below and a plasma emission wavelength of 350 nm or greater.