A method of erasing memory cells of a string of series-connected memory cells of a memory, the method comprising: developing a first voltage level in a first semiconductor material of a first conductivity type forming channel regions for a first grouping of memory cells of the string of series-connected memory cells during an erase operation; while developing the first voltage level in the first semiconductor material, developing a second voltage level, less than the first voltage level, in a second semiconductor material of the first conductivity type forming channel regions for a second grouping of memory cells of the string of series-connected memory cells; and while developing the first voltage level in the first semiconductor material and while developing the second voltage level in the second semiconductor material, applying a third voltage level to control gates of the first grouping of memory cells and applying a fourth voltage level, less than the third voltage level, to control gates of the second grouping of memory cells; wherein the memory comprises a third semiconductor material of the first conductivity type forming channel regions for a third grouping of memory cells of the string of series-connected memory cells; wherein the string of series-connected memory cells has a first end selectively connected to a data line of the memory, and has a second end, opposite the first end, selectively connected to a common source of the memory; wherein the first semiconductor material, the second semiconductor material and the third semiconductor material are connected in series between the data line and the common source; wherein the first semiconductor material is electrically connected to the second semiconductor material through a first conductive portion of a semiconductor material of a second conductivity type different than the first conductivity type; and wherein the second semiconductor material is electrically connected to the third semiconductor material through a second conductive portion of the semiconductor material of the second conductivity type. developing a first voltage level in a first semiconductor material of a first conductivity type forming channel regions for a first grouping of memory cells of the string of series-connected memory cells during an erase operation; while developing the first voltage level in the first semiconductor material, developing a second voltage level, less than the first voltage level, in a second semiconductor material of the first conductivity type forming channel regions for a second grouping of memory cells of the string of series-connected memory cells; and while developing the first voltage level in the first semiconductor material and while developing the second voltage level in the second semiconductor material, applying a third voltage level to control gates of the first grouping of memory cells and applying a fourth voltage level, less than the third voltage level, to control gates of the second grouping of memory cells; wherein the memory comprises a third semiconductor material of the first conductivity type forming channel regions for a third grouping of memory cells of the string of series-connected memory cells; wherein the string of series-connected memory cells has a first end selectively connected to a data line of the memory, and has a second end, opposite the first end, selectively connected to a common source of the memory; wherein the first semiconductor material, the second semiconductor material and the third semiconductor material are connected in series between the data line and the common source; wherein the first semiconductor material is electrically connected to the second semiconductor material through a first conductive portion of a semiconductor material of a second conductivity type different than the first conductivity type; and wherein the second semiconductor material is electrically connected to the third semiconductor material through a second conductive portion of the semiconductor material of the second conductivity type.