Semiconductor device having elongated electrostatic protection element along long side of semiconductor chip

1. A semiconductor device, comprising:

an output circuit region shaped approximately as a rectangle having a long side and a short side; and

an electrostatic protection element region which is formed along said long side of said output circuit region and which has a substantially rectangular shape having a long side approximately equal in length to said long side of said output circuit region,

wherein said electrostatic protection element region includes:

a single first diffusion region of a first conductivity type which mostly extends from one end to an other end of said long side in said electrostatic protection element;

a second diffusion region of a second conductivity type formed on the single first diffusion region and which acts as a cathode; and

a third diffusion region of the first conductive type formed on the single first diffusion region and which acts as an anode,

wherein said first, second, and third diffusion regions forming a single diode structure approximately equal in length to said long side of said output region,

wherein said output circuit region comprises a plurality of output circuits,

wherein each of said plurality of output circuits includes a first channel type transistor formed in a first region and a second channel type transistor formed in a second region, and

wherein said electrostatic protection element region is formed between said first region and said second region.

2. The semiconductor device according to claim 1 , wherein the first diffusion region includes a single second diffusion region which mostly extends from one end to the other end of said long side in said electrostatic protection region.

3. The semiconductor device according to claim 1 , wherein the first diffusion region includes a plurality of second diffusion regions, partitioned by a ring-like insulating film, for every of each of a corresponding one of said output circuits.

4. The semiconductor device according to claim 3 , wherein said plurality of second diffusion regions are connected to each other through a wire, to form as one electrostatic protection element.

5. The semiconductor device according to claim 3 , wherein a number of said second diffusion regions is less than a number of outputs of the semiconductor device.

6. The semiconductor device according to claim 1 , wherein the first diffusion region includes a plurality of second diffusion regions, partitioned by a ring-like insulating film, for every part of said plurality of output circuits.

7. The semiconductor device according to claim 1 ,

wherein said electrostatic protection element region is provided with an inter-power electrostatic protection element which is formed commonly to said plurality of output circuits.

8. The semiconductor device of claim 1 , wherein each said plurality of output circuits comprise a first transistor type connected to a first power supply voltage and a second transistor type connected to a second power supply voltage,

wherein respective connections between each said plurality of output circuits and said first and second power supply voltages are equalized in length so that values of a line resistance between said first and second power supply voltages for each said output circuit are substantially equal.

9. A semiconductor device, comprising:

an output circuit region shaped approximately as a rectangle having a long side and a short side; and

an electrostatic protection element region which is formed along said long side of said output circuit region and which has a substantially rectangular shape having a long side approximately equal in length to said long side of said output circuit region,

wherein said output circuit region comprises a plurality of output circuits,

wherein said electrostatic protection element region includes:

a single first diffusion region of a first conductivity type which mostly extends from one end to an other end of said long side in said electrostatic protection element;

a plurality of second diffusion regions of the first conductivity type formed on the single first diffusion region, which acts as an anode, and extending from one end to an other end of said long side so as to be less than a number of said output circuits, and

a plurality of third diffusion regions of a second conductive type formed on the single first diffusion region, which acts as a cathode, and provided more than a number of said second diffusion regions,

wherein said plurality of second diffusion regions are connected to each other through a first wire and said plurality of third diffusion regions are connected to each other through a second wire,

wherein said first, second, and third diffusion regions form a single diode structure approximately equal in length to said long side of said output region,

wherein said output circuit region comprises a plurality of output circuits,

wherein each of said plurality of output circuits includes a first channel type transistor formed in a first region and a second channel type transistor formed in a second region, and

wherein said electrostatic protection element region is formed between said first region and said second region.

10. The semiconductor device of claim 9 , wherein each said plurality of output circuits comprise a first transistor type connected to a first power supply voltage and a second transistor type connected to a second power supply voltage,

wherein respective connections between each said plurality of output circuits and said first and second power supply voltages are equalized in length so that values of a line resistance between said first and second power supply voltages for each said output circuit are substantially equal.

11. A semiconductor device, comprising:

an input circuit region shaped approximately as a rectangle having a long side and a short side, said long side being arranged along an edge of a long side of a semiconductor chip and placed adjacent to said edge of said long side of said semiconductor chip;

an output circuit region shaped approximately as a rectangle having a long side and a short side, said output circuit being placed adjacent to an other edge of said long side of said semiconductor chip, said output circuit region including a first portion where a first channel type transistor is formed, and a second portion where a second channel type transistor is formed, each of said first and second portions having a length substantially equal to that of said long side of said output circuit region;

an electrostatic protection element region which is formed in said output circuit region and has a length substantially equal to that of said long side of said output circuit region; and

a pad region arranged at a periphery region of said semiconductor chip to surround said input and output circuit regions,

wherein said electrostatic protection element region includes:

a single first diffusion region of a first conductivity type which extends from one end to an other end of said long side in said electrostatic protection element region;

a second diffusion region of a second conductivity type formed on the single first diffusion region and which acts as a cathode; and

a third diffusion region of the first conductivity type formed on the single first diffusion region and which acts as an anode,

wherein said first, second, and third diffusion regions form a single diode structure approximately equal in length to said long side of said output region,

wherein said output circuit region comprises a plurality of output circuits,

wherein each of said plurality of output circuits includes a first channel type transistor formed in a first region and a second channel type transistor formed in a second region, and

wherein said electrostatic protection element region is formed between said first region and said second region.

12. The semiconductor device as claimed in claim 11 , wherein said electrostatic protection element region is formed between said first and second portions.

13. The semiconductor device according to claim 11 , wherein the first diffusion region includes a single second diffusion region which mostly extends from one end to the other end of said long side in said electrostatic protection region.

14. The semiconductor device according to claim 11 , wherein the first diffusion region includes a plurality of second diffusion regions, partitioned by a ring-like insulating film.

15. The semiconductor device of claim 11 , wherein said output circuit region comprises a plurality of output circuit regions, each said plurality of output circuit regions comprising said first transistor type connected to a first power supply voltage and said second transistor type connected to a second power supply voltage,

wherein respective connections between each said plurality of output circuits and said first and second power supply voltages are equalized in length so that values of a line resistance between said first and second power supply voltages for each said output circuit region are substantially equal.