Suppose that it is suggested that the n-well in a NAND Flash memory cell should be grounded at all times except when the array is being erased. Is this OK? What would be a potential benefit? Explain...

Suppose that it is suggested that the n-well in a NAND Flash memory cell should be grounded at all times except when the array is being erased. Is this OK? What would be a potential benefit?

Explain in your own words and with the help of pictures why a top select MOSFET is needed in a NAND Flash memory cell.