Solid-state imaging device with specific contact arrangement
View Patent ↗In each photosensitive cell, a photodiode 101 , a transfer gate 102 , a floating diffusion layer section 103 , an amplifier transistor 104 , and a reset transistor 105 are formed in one active region surrounded by a device isolation region. The floating diffusion layer section 103 included in one photosensitive cell is connected not to the amplifier transistor 104 included in that cell but to the gate of the amplifier transistor 104 included in another photosensitive cell adjacent to the one photosensitive cell in the column direction. A polysilicon wire 111 connects the transfer gates 102 arranged in the same row, and a polysilicon wire 112 connects the reset transistors 105 arranged in the same row. For connection in the row direction, only polysilicon wires are used.
1. An imaging device formed in a semiconductor substrate, the imaging device comprising:
a plurality of photodiodes arranged in rows and columns, each photodiode for a given row of photodiodes formed in a corresponding active region of the semiconductor substrate;
a transfer gate disposed over the first active region so as to define an associated photodiode on one side of the transfer gate and an associated floating diffusion element on another side of the transfer gate;
an amplifier transistor;
a reset transistor;
a first wire electrically connecting the associated floating diffusion element to a gate electrode of the amplifier transistor;
a second contact hole connecting a drain of the reset transistor to a third wire disposed over the first semiconductor substrate;
a third contact hole connecting the associated floating diffusion element to the first wire; and
a fourth contact hole connecting the gate electrode of the amplifier transistor to the first wire, wherein:
the amplifier transistor is formed in another active region which is separated from the corresponding active region where the associated floating diffusion element connected to the gate of the amplifier transistor is formed,
the first wire is disposed in a column direction between the associated floating diffusion element and the gate electrode of the associated amplifier transistor, and
the second, third and fourth contact holes are aligned substantially in a straight line.
2. The imaging device according to claim 1 ,
wherein the first wire includes a straight portion disposed in the column direction.
3. The imaging device according to claim 1 ,
wherein the first wire includes a portion disposed in a direction traversing column direction.
4. The imaging device according to claim 1 ,
wherein the first wire includes a straight portion disposed in a first column direction and another portion disposed in a direction traversing column direction, and
the straight portion is connected to the associated floating diffusion element.
5. The imaging device according to claim 1 ,
wherein transfer gates corresponding to adjacent photodiodes are formed by a continuous conducting material layer.
6. The imaging device according to claim 1 ,
wherein the reset transistor and the amplifier transistor are arranged between adjacent photodiodes in a row direction.
7. The imaging device according to claim 1 ,
wherein the amplifier transistor and the reset transistor share a common drain.
8. An imaging device formed in a semiconductor substrate, the imaging device comprising:
a plurality of photodiodes arranged in rows and columns, each photodiode for a given row of photodiodes formed in a corresponding active region of the semiconductor substrate;
a transfer gate disposed over the first active region so as to define an associated photodiode on one side of the transfer gate and an associated floating diffusion element on another side of the transfer gate;
an amplifier transistor;
a reset transistor;
a first wire electrically connecting the associated floating diffusion element to a gate electrode of the amplifier transistor;
a third contact hole connecting the associated floating diffusion element to the first wire; and
a fourth contact hole connecting the gate electrode of the amplifier transistor to the first wire, wherein:
the amplifier transistor is formed in another active region which is separated from the corresponding active region where the associated floating diffusion element connected to the gate of the amplifier transistor is formed,
the first wire is disposed in a column direction between the associated floating diffusion element and the gate electrode of the associated amplifier transistor,
the first wire is disposed in approximately a straight line between the associated floating diffusion element and the gate electrode of the amplifier transistor, and
the third contact hole and he fourth contact hole are aligned in the column direction.
9. The imaging device according to claim 8 , wherein the amplifier transistor and the reset transistor share a common drain.
10. An imaging device formed in a semiconductor substrate, the imaging device comprising:
a plurality of photodiodes arranged in rows and columns, each photodiode for a given row of photodiodes formed in a corresponding active region of the semiconductor substrate;
a transfer gate disposed over the first active region so as to define an associated photodiode on one side of the transfer gate and an associated floating diffusion element on another side of the transfer gate;
an amplifier transistor;
a reset transistor;
a first wire electrically connecting the associated floating diffusion element to a gate electrode of the amplifier transistor;
a first contact hole connected to a second wire disposed over the semiconductor substrate and being for receiving an output of a source of the amplifier transistor;
a second contact hole connecting a drain of the reset transistor to a third wire disposed over the first semiconductor substrate; and
a third contact hole connected to a source of the reset transistor,
wherein the first, second, and third contact holes are aligned substantially in a straight line.
11. The imaging device according to claim 10 ,
wherein the first wire includes a straight portion disposed in the column direction.
12. The imaging device according to claim 10 ,
wherein the first wire includes a portion disposed in a direction traversing column direction.
13. The imaging device according to claim 10 , wherein:
the first wire includes a straight portion disposed in a first column direction and another portion disposed in a direction traversing column direction, and
the straight portion is connected to the associated floating diffusion element.
14. The imaging device according to claim 10 ,
wherein transfer gates corresponding to adjacent photodiodes are formed by a continuous conducting material layer.
15. The imaging device according to claim 10 ,
wherein the amplifier transistor and the reset transistor share a common drain.
16. The imaging device according to claim 10 ,
wherein the first wire is disposed in approximately a straight line between the associated floating diffusion element and the gate electrode of the amplifier transistor.
17. An imaging device formed in a semiconductor substrate, the imaging device comprising:
a plurality of photodiodes arranged in rows and columns, each photodiode for a given row of photodiodes formed in a corresponding active region of the semiconductor substrate;
a transfer gate disposed over the first active region so as to define an associated photodiode on one side of the transfer gate and an associated floating diffusion element on another side of the transfer gate;
an amplifier transistor;
a reset transistor;
a first wire electrically connecting the associated floating diffusion element to a gate electrode of the amplifier transistor;
a first contact hole connected, to receive an output of a source of the amplifier transistor, to a second wire disposed over the semiconductor substrate;
a third contact hole connected to a source of the reset transistor; and
a second contact hole connected, to supply an input to a drain of the amplifier transistor, to a third wire disposed over the first semiconductor substrate; and
wherein the first, second and third contact holes are aligned substantially in a straight line.
18. The imaging device according to claim 17 ,
wherein the first wire includes a straight portion disposed in the column direction.
19. The imaging device according to claim 17 ,
wherein the first wire includes a portion disposed in a direction traversing column direction.
20. The imaging device according to claim 17 , wherein:
the first wire includes a straight portion disposed in a first column direction and another portion disposed in a direction traversing column direction, and
the straight portion is connected to the associated floating diffusion element.
21. The imaging device according to claim 17 ,
wherein transfer gates corresponding to adjacent photodiodes are formed by a continuous conducting material layer.
22. The imaging device according to claim 17 ,
wherein the amplifier transistor and the reset transistor share a common drain.