SCR cell for electrical overstress protection of electronic circuits
US6236087A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 1998 |
| Grant date | May 22, 2001 |
| Priority date | — |
| Expiry date | Nov 2, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/126
Abstract
An input protection device is provided for protecting a circuit structure which is coupled to a first node, the device comprising a first lightly-doped region of P-type material with a lightly doped well of N-type material formed in it. Two regions of heavily doped N-type and P-type material, which are electrically connected to the first node, are formed in the well of N-type material. A third heavily doped region of N type material is formed in the first lightly-doped region of P-type material and is electrically connected to a reference node. In a first aspect of this invention, the third heavily doped region of N type material is formed in a second well of N-type material, which in turn is formed in the first lightly-doped region of P-type material. In this first aspect of the invention a further region of heavily doped P-type material is formed in the second well of N-type material, this further region of heavily doped P-type material being electrically connected to the reference node. In a second aspect to the invention, a further region of heavily doped P-type material is formed in the first lightly-doped region of P-type material. In a third aspect to the invention, the thir…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.