Dummy voltage to reduce first read effect in memory
US9911500B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 2016 |
| Grant date | Mar 6, 2018 |
| Priority date | — |
| Expiry date | Apr 18, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2211/5621
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Techniques are provided for improving the accuracy of read operations of memory cells, where the threshold voltage (Vth) of a memory cell can shift depending on when the read operation occurs. In one aspect, a dummy voltage is applied to the word lines to cause a coupling up of the word lines and weak programming. This can occur when a specified amount of time has elapsed since a last program or read operation, or when a power on event is detected for the memory device. A number of read errors can also be considered. The dummy voltage is similar to a pass voltage of a program or read operation but no sensing is performed. The word line voltages are therefore provided at a consistently up-coupled level so that read operations are consistent. The coupling up occurs due to capacitive coupling between the word line and the channel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.