Forming method of resistive random-access memory array

A forming method of a resistive random-access memory (ReRAM) array, comprising:

• applying a first pulse to a first ReRAM unit in the ReRAM array;
• applying a second pulse to the first ReRAM unit, wherein an electrical property of the first pulse is opposite to that of the second pulse;
• applying a verification pulse to the first ReRAM unit to verify whether a first resistance value of the first ReRAM unit passes a preset threshold;
• when the first resistance value passes the preset threshold value, a third pulse is applied to the first ReRAM unit, wherein the first pulse and the third pulse have a same electrical property, and the first pulse has a voltage value substantially the same to that of the third pulse;
• applying the first pulse to a second ReRAM unit in the ReRAM array, wherein the first ReRAM unit and the second ReRAM unit are electrically connected to each other through a bit line;
• applying the second pulse to the second ReRAM unit;
• applying the verify pulse to the second ReRAM unit;
• and
• when a second resistance value of the second ReRAM unit passes the preset threshold value, the third pulse is applied to the second ReRAM unit.