Patent attributes
Methods of operating a memory include developing first and second voltage levels in first and second semiconductor materials, respectively, forming channel regions for first and second groupings of memory cells, respectively, of a string of series-connected memory cells during an erase operation while applying a third voltage level to control gates of the first grouping of memory cells and applying a fourth voltage level to control gates of the second grouping of memory cells. Apparatus include different groupings of memory cells of a string of series-connected memory cells adjacent respective portions of semiconductor material having a first conductivity type and separated from adjacent portions of semiconductor material having the first conductivity type by portions of semiconductor material having a second conductivity type, and a controller configured to apply respective and different voltage levels to control gates of memory cells of respective different groupings of memory cells during an erase operation.
