Electrostatic discharge protection device
First Claim
1. An electrostatic discharge protected device formed on a substrate, comprising:
- a first part being loop-shaped;
a second part located in and separated from the first looped part;
a third part being loop-shaped and positioned between the first and second parts for conducting the first and second parts in a first instance and for isolating the first and second parts in a second instance;
a loop-shaped inner diffusion area for biasing the substrate, said inner diffusion area surrounding said first, second and third parts, and being the same diffusion type as the substrate; and
a loop-shaped outer diffusion area working as a latchup guard ring, said outer diffusion area surrounding said loop-shaped inner diffusion area, and being of an opposite diffusion type than the substrate.
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Abstract
The present invention is an electronic device, and more particularly an MOS transistor. A square-type layout style is used to realize the MOS device. By using the present layout style, the output driving/sinking capability of output buffers as well as the ESD protection capability of NMOS and PMOS devices in output buffers or input ESD protection circuits are significantly improved within smaller layout area. Both drain diffusion area and drain-to-bulk parasitic capacitance at the output node are reduced by this square-type layout. Devices using the present layout style can be assembled to form larger, rectangular (or square) and similarly functioning devices. Thus, the present square-type layout style is very attractive to submicron CMOS VLSI/ULSI in high-density and high-speed applications.
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Citations
9 Claims
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1. An electrostatic discharge protected device formed on a substrate, comprising:
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a first part being loop-shaped; a second part located in and separated from the first looped part; a third part being loop-shaped and positioned between the first and second parts for conducting the first and second parts in a first instance and for isolating the first and second parts in a second instance; a loop-shaped inner diffusion area for biasing the substrate, said inner diffusion area surrounding said first, second and third parts, and being the same diffusion type as the substrate; and a loop-shaped outer diffusion area working as a latchup guard ring, said outer diffusion area surrounding said loop-shaped inner diffusion area, and being of an opposite diffusion type than the substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification