Highly scalable hafnium oxide memory with improvements of resistive distribution and read disturb immunity

Abstract

A 30x30 nm2 HfOx resistance random access memory (RRAM) with excellent electrical performances is demonstrated for the scaling feasibility in this work. A 1 Kb one transistor and one resistor (1T1R) array with robust characteristics was also fabricated successfully. The device yield of the 1 Kb array is 100%, and the endurance for these devices can exceed 106 cycles by a pulse width of 40 ns. Two effective verification methods, which make a tight distribution of high resistance (RHIGH) and low resistance (RLOW) are proposed for the array to ensure a good operation window. A thin AlOx buffer layer under the HfOx layer was adopted to enhance the read disturb immunity. Without large parasitic capacitance, the 1T1R RRAM devices exhibit excellent program(PGM)/erase(ERS) disturb immunity. © 2009 IEEE.