Patent ID: 8289776

Claim:
A method for operating memory cells, comprising: applying a read voltage to a word line of a selected cell while applying a pass voltage to word lines of unselected cells, the memory cells programmable to a number of positive program states and a number of negative program states, wherein a lowermost threshold voltage (Vt) corresponding to the number of negative program states is âˆ’2V to âˆ’4V and an uppermost Vt corresponding to the number of positive program states is 2V to 4V; applying a boost voltage to a source line coupled to the selected cell, wherein the boost voltage is 1V to 2V, and wherein the read voltage is 0V to a sum of the uppermost Vt corresponding to the number of positive program states and the boost voltage; applying a voltage greater than the boost voltage to a bit line of the selected cell; applying a ground potential to a well region associated with the selected cell; and sensing a current variation of the bit line in response to the selected cell changing from a non-conducting state to a conducting state.