Variable program voltage increment values in non-volatile memory program operations
US7474561B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 2006 |
| Grant date | Jan 6, 2009 |
| Priority date | — |
| Expiry date | Oct 10, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/3481
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The lowest programmed state in multi-state non-volatile flash memory devices can suffer from an increased level of bit line to bit line capacitive charge coupling when compared with other states. Program voltages applied to memory cells as increasing voltage pulses can be incremented using smaller values when programming memory cells to the lowest programmable state. Smaller increments in the applied voltage allow for greater precision and a narrower threshold voltage distribution to compensate for the disproportionate charge coupling experienced by cells programmed to this state. Smaller increment values can be used when switching from lower page to upper page programming in some implementations. In a pipelined programming architecture where cells forming a physical page store two logical pages of data and programming for one logical page begins before receiving data for the other logical page, the increment value can be increased when switching from programming the first logical page to programming both pages concurrently.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.