Biasing an integrated circuit well with a transistor electrode
US6133597A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 1997 |
| Grant date | Oct 17, 2000 |
| Priority date | — |
| Expiry date | Jul 25, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B12/50
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Dynamic Random Access Memory (DRAM) cells are formed in a P well formed in a biased deep N well (DNW). PMOS transistors are formed in N wells. The NMOS channels stop implant mask is modified not to be a reverse of the N well mask in order to block the channels stop implant from an N+ contact region used for DNW biasing. In DRAMs and other integrated circuits, a minimal spacing requirement between a well of an integrated circuit on the one hand and adjacent circuitry on the other hand is eliminated by laying out the adjacent circuitry so that the well is located adjacent to a transistor having an electrode connected to the same voltage as the voltage that biases the well. For example, in DRAMs, the minimal spacing requirement between the DNW and the read/write circuitry is eliminated by locating the DNW next to a transistor precharging the bit lines before memory accesses. One electrode of the transistor is connected to a precharge voltage. This electrode overlaps the DNW which is biased to the same precharge voltage. This electrode provides the DNW N+ contact region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.