Patent ID: 8470637

Claim:
A method for fabricating a resistor for a resistance random access memory (RRAM), comprising: (a) forming a first electrode over a substrate; (b) depositing zirconium oxide on the first electrode by a sputtering technique under a working temperature ranging from 175° C. to 225° C. to form a variable resistance layer of zirconium oxide, wherein formation of the variable resistance zirconium oxide layer at said working temperature enhances a number of times that the resistor can be continuously switched between ON-state and OFF-state during a specified voltage sweeping span as compared with the number when the variable resistance zirconium oxide layer is formed at a working temperature of 250° C., the number being at least 6800 times when the variable resistance zirconium oxide layer is formed at said working temperature and the voltage sweeping span comprises application of a DC voltage sweep from 0 V to +1.5 V, back to 0 V, then to −2.5 V, and back to 0 V with a sweeping voltage step of 0.1 V; and (c) forming a second electrode of Ti on the variable resistance layer.