Solid state imaging apparatus and method for fabricating the same
View Patent ↗A semiconductor device of the present invention includes a substrate; an imaging region which is formed at part of the substrate and in which photoelectric conversion cells including photoelectric conversion sections are arranged in the form of an array; a control-circuit region which is formed at part of the substrate and in which the imaging region is controlled and a signal from the imaging region is outputted; and a copper-containing interconnect layer formed above the substrate and made of a material containing copper. Furthermore, a first anti-diffusion layer and a second anti-diffusion layer are formed, as anti-diffusion layers for preventing the copper from diffusing into each photoelectric conversion section, on the photoelectric conversion section and the copper-containing interconnect layer, respectively.
1. A solid state imaging apparatus comprising:
a substrate;
a photoelectric conversion section formed in a top surface of a portion of the substrate;
a plurality of copper-containing interconnect layers formed above portions of the substrate except the photoelectric conversion section;
a first anti-diffusion layer covering said photoelectric conversion section to prevent copper from diffusing into the photoelectric conversion section; and
second anti-diffusion layers formed on said plurality of copper-containing interconnect layers,
wherein the first anti-diffusion layer, and the second anti-diffusion layer formed directly on the lowermost of the plurality of copper-containing interconnect layers are integrally formed as a continuous layer.
2. The solid state imaging apparatus of claim 1 , wherein the first and second anti-diffusion layers are made of a dielectric material containing at least one of nitrogen and carbon.
3. The solid state imaging apparatus of claim 1 , wherein the distance between the photoelectric conversion section and the first anti-diffusion layer is greater than or equal to 5 nm and less than or equal to 20 nm.
4. The solid-state imaging apparatus of claim 1 , wherein the first anti-diffusion layer is made of silicon nitride, and has a thickness of greater than or equal to 50 nm and less than or equal to 130 nm.
5. The solid-state imaging apparatus of claim 1 , wherein the second anti-diffusion layers are made of silicon carbide, and each have a thickness of greater than or equal to 40 nm and less than or equal to 90 nm.
6. The solid-state imaging apparatus of claim 1 further comprising:
an imaging region which is formed on the substrate, and in which photoelectric conversion cells including multiple ones of the photoelectric conversion section are arranged in the form of an array; and
a control-circuit region which is formed on the substrate, and in which the imaging region is controlled and a signal from the imaging region is outputted.
7. The solid-state imaging apparatus of claim 1 , wherein a height of a lowermost layer of the second anti-diffusion layers is equal to or greater than a height of the first anti-diffusion layer.
8. The solid-state imaging apparatus of claim 7 , wherein at least one of the plurality of copper-containing interconnect layers is formed on the lowermost second anti-diffusion layer.