Write verify methods for resistance random access memory (RRAM) are
disclosed. The methods include applying a reset operation voltage pulse
across a RRAM cell to change a resistance of the RRAM cell from a low
resistance state to a high resistance state and setting a counter to
zero. Then the method includes applying a forward resetting voltage pulse
across the RRAM cell if the RRAM cell has a high resistance state
resistance value less than a selected lower resistance limit value and
adding one to the counter. This step is repeated until either the counter
reaches a predetermined number or until the high resistance state
resistance value is greater than the lower resistance limit value. The
method also includes applying a reverse resetting voltage pulse across
the RRAM cell if the RRAM cell has a high resistance state resistance
values is greater than a selected upper resistance limit value and adding
one to the counter. The reverse resetting voltage pulse has a second
polarity being opposite the first polarity. This step is repeated until
either the counter reaches a predetermined number or until all the high
resistance state resistance value is less than the upper resistance limit
value.