Memory device and method of operating the same

A method of operating a memory device, the method comprising:

• establishing the quantity of valid data stored in a selected memory block;
• performing a copyback operation on the selected memory block when the quantity of valid data is less than a predetermined value;
• and
• performing an overwrite operation on selected memory cells corresponding to an erase state, or the erase state and at least one program state, among memory cells included in the selected memory block.

A method of operating a memory device, the method comprising:

• establishing a quantity of valid data stored in a selected memory block on which a background operation is performed;
• identifying the selected memory block as an overwrite operation object memory block based on the quantity of valid data;
• performing a copyback operation including storing, in a target memory block, the valid data stored in the selected memory block;
• and
• performing an overwrite operation including increasing a threshold voltage of selected memory cells corresponding to an erase state, or the erase state and at least one program state, among memory cells included in the selected memory block to at least a predetermined threshold voltage value after the copyback operation.

A method comprising:

• establishing a quantity of valid data stored in a first memory block of a plurality of memory blocks;
• when the quantity of valid data is less than a predetermined value, performing a copyback operation including storing, in a second memory block of the plurality of memory blocks, the valid data stored in the first memory block;
• and
• performing an overwrite operation including increasing a threshold voltage of a plurality of memory cells of the first memory block to at least a predetermined threshold voltage value based on the quantity of valid data stored in the first memory block.