Abstract: A wafer surface cleaning method is provided comprising immersion of the wafer in a H.sub.2 O:NH.sub.4 OH:H.sub.2 O.sub.2 solution at a temperature less than 65.degree. C. prior to formation of a thin oxide such as a tunnel oxide or gate oxide. Immersion of the wafer in a sub-65.degree. C. NH.sub.4 OH results in a smoother wafer surface that increase the charge-to-breakdown (Q.sub.BD) of the subsequently formed oxide. In the tunnel oxide embodiment, the lower temperature solution also reduces the oxide etch rate of the solution enabling a minimum overgrowth of gate oxide which, in turn, enables the addition of an in situ growth temperature anneal of the gate oxide without altering other process parameters.

Abstract: A non-volatile memory device is provided having an array of single transistor memory cells read in accordance with an improved read cycle operation. That is, a selected cell mutually connected via a single bit line to other cells is assured activation necessary to discern a programmed or unprogrammed state of that cell. The non-selected cells connected to the selected cell are advantageously assured of non-activation by applying a negative voltage to the word lines associated with those cells. The negative voltage is less than the threshold voltage associated with the single transistor MOS device. The non-selected cells are thereby retained inactive to provide a singular active or inactive selected cell dependent solely upon the programmed state of the array. Negative voltage upon the non-selected cells provides minimal leakage of over-erased cells normally associated with depletion mode operation.