MOS image pick-up device and camera incorporating the same
View Patent ↗A MOS image pick-up device including a semiconductor substrate, an imaging region formed on the semiconductor substrate by arraying plural unit pixels, and a peripheral circuit region including a driving circuit for operating the imaging region formed on the semiconductor substrate; the unit pixels include a photodiode, MOS (metal-oxide-semiconductor) transistors and a first device-isolation portion, the peripheral circuit region includes a second device-isolation portion for isolating devices in the driving circuit; wherein each of the first device-isolation portion and the second device-isolation portion is at least one portion selected from an electrically insulating film formed on the substrate in order not to erode the substrate, a electrically insulating film formed on the substrate so as to erode the substrate to a depth ranging from 1 nm to 50 nm, and an impurity diffusion region formed within the substrate. The MOS image pick-up device is incorporated in a camera. Thereby, devices are isolated between MOS transistors, and noise caused by leakage current is decreased.
1. A MOS (metal-oxide-semiconductor) image pick-up device comprising:
a semiconductor substrate,
an imaging region formed on the semiconductor substrate by arraying plural unit pixels, and
a peripheral circuit region comprising a driving circuit for operating the imaging region formed on the semiconductor substrate;
where each of the unit pixels comprises: a photodiode, MOS transistors, and a first device-isolation portion comprising a portion next to the photodiode and a portion not next to the photodiode, and
the peripheral circuit region comprises a second device-isolation portion for isolating devices in the driving circuit,
wherein the following are satisfied:
I. each of the first device-isolation portion not next to the photodiode and the second device-isolation portion has a structure comprising:
A. an electrically insulating film formed on a surface of the substrate so as to erode the substrate to a depth in a range of 1 nm to 50 nm, or
B. both an electrically insulating film formed on a surface of the substrate so as to erode the substrate to a depth in a range of 1 nm to 50 nm and an impurity diffusion region formed within the substrate, and
II. each of the first device-isolation portions next to the photodiode has a structure consisting of only an impurity diffusion region formed within the substrate directly under the substrate surface.
2. The MOS image pick-up device according to claim 1 , wherein the impurity diffusion region is formed by ion implantation.
3. The MOS image pick-up device according to claim 1 , wherein at least one part of the driving circuit is a dynamic circuit.
4. The MOS image pick-up device according to claim 1 , wherein the photodiode has a surface portion having a dark current inhibiting layer.
5. The MOS image pick-up device according to claim 1 , wherein the first device-isolation portion and the second device-isolation portion are formed by annealing in a hydrogen atmosphere.
6. A camera comprising a MOS (metal-oxide-semiconductor) image pick-up device comprising:
a semiconductor substrate,
an imaging region formed on the semiconductor substrate by arraying plural unit pixels, and
a peripheral circuit region comprising a driving circuit for operating the imaging region formed on the semiconductor substrate;
where each of the unit pixels comprises: a photodiode, MOS transistors, and a first device-isolation portion comprising a portion next to the photodiode and a portion not next to the photodiode, and
the peripheral circuit region comprises a second device-isolation portion for isolating devices in the driving circuit,
wherein the following are satisfied:
I. each of the first device-isolation portion not next to the photodiode and the second device-isolation portion has a structure comprising:
A. an electrically insulating film formed on a surface of the substrate so as to erode the substrate to a depth in a range of 1 nm to 50 nm, or
B. both an electrically insulating film formed on a surface of the substrate so as to erode the substrate to a depth in a range of 1 nm to 50 nm and an impurity diffusion region formed within the substrate, and
II. each of the first device-isolation portions next to the photodiode has a structure consisting of only an impurity diffusion region formed within the substrate directly under the substrate surface.
7. The camera according to claim 6 , wherein the impurity diffusion region is formed by ion implantation.
8. The camera according to claim 6 , wherein at least one part of the driving circuit is a dynamic circuit.
9. The camera according to claim 6 , wherein the photodiode has a surface portion having a dark current inhibiting layer.
10. The camera according to claim 6 , wherein the first device-isolation portion and the second device-isolation portion are formed by annealing in a hydrogen atmosphere.
11. A MOS (metal-oxide-semiconductor) image pick-up device comprising:
a semiconductor substrate,
an imaging region formed on the semiconductor substrate by arraying plural unit pixels, and
a peripheral circuit region comprising a driving circuit for operating the imaging region formed on the semiconductor substrate;
where each of the unit pixels comprises: a photodiode, MOS transistors, and a first device-isolation potion, and
the peripheral circuit region comprises a second device-isolation portion for isolating devices in the driving circuit,
wherein the following are satisfied:
I. the first device-isolation portion has a structure comprising:
A. an electrically insulating film formed on a surface of the substrate so as to erode the substrate to a depth in a range of 1 nm to 50 nm, or
B. an impurity diffusion region formed within the substrate directly under the substrate surface, and
II. the first device-isolation portion and the second device-isolation portion have respective structures selected separately so as to be different from each other.
12. A MOS (metal-oxide-semiconductor) image pick-up device comprising:
a semiconductor substrate,
an imaging region formed on the semiconductor substrate by arraying plural unit pixels, and
a peripheral circuit region comprising a driving circuit for operating the imaging region formed on the semiconductor substrate;
where each of the unit pixels comprises: a photodiode, MOS transistors, and a first device-isolation portion, and
the peripheral circuit region comprises a second device-isolation portion or isolating devices in the driving circuit,
wherein the following is satisfied:
the first device-isolation portion and the second device-isolating portion are selected separately from respective structures comprising:
A. an electrically insulating film formed on a surface of the substrate so as to erode the substrate to a depth in a range of 1 nm to 50 nm, or
B. an impurity diffusion region formed within the substrate directly under the substrate surface.
13. A camera comprising a MOS ( metal - oxide - semiconductor ) image pick - up device comprising:
a semiconductor substrate:
an imaging region formed on the semiconductor substrate by arraying plural unit pixels, and
a peripheral circuit region comprising a driving circuit for operating the imaging region formed on the semiconductor substrate;
where each of the unit pixels comprises: a photodiode, MOS transistors, and a first device - isolation portion, and
the peripheral circuit region comprises a second device - isolation portion for isolating devices in the driving circuit,
wherein the following is satisfied:
I. the first device - isolation portion has a structure comprising:
A. an electrically insulating film formed on a surface of the substrate so as to erode the substrate to a depth in a range of 1 nm to 50 nm, or
B. an impurity diffusion region formed within the substrate directly under the substrate surface, and
II. the first device - isolation portion and the second device - isolation portion have respective structures selected separately so as to be different from each other.