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1071-F07-08

Nonvolatile resistive switching characteristics of HfO2 with Cu doping Weihua Guan1, Shibing Long1, Ming Liu1, and Wei Wang2 1 Lab of Nano-fabrication and Novel Devices Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing, 100029, China, People's Republic of 2 College of Nanoscale Science and Engineering, University at Albany, Albany, NY, 12203 ABSTRACT In this work, resistive switching characteristics of hafnium oxide (HfO2) with Cu doping prepared by electron beam evaporation are investigated for nonvolatile memory applications. The top metal electrode/ hafnium oxide doped with Cu/n+ Si structure shows two distinct resistance states (high-resistance and low-resistance) in DC sweep mode. By applying a proper bias, resistance switching from one state to the other state can be achieved. Though the ratio of high/low resistance is less than an order, the switching behavior is very stable and uniform with nearly 100% device yield. No data loss is found upon continuous readout for more than 104 s. The role of the intentionally introduced Cu impurities in the resistive switching behavior is investigated. HfO2 films with Cu doping are promising to be used in the nonvolatile resistive switching memory devices. INTRODUCTION Recently, reversible and reproducible resistive switching phenomena induced by external electric field have been extensively studied due to its potential applications in resistive random access memories (RRAM) [1]-[14]. The typical cell of this kind of memory is a capacitor-like structure: a functional material sandwiched between two conductive electrodes. This type of memory devices can be characterized by two distinct resistance states: OFF state (with high resistance) and ON state (with low resistance). RRAM offers the possibility of high density integration, low power operation, and multilevel storage. The current candidate materials for this type of memories include ferromagnetic material such as Pr1-xCaxMnO3 (PCMO) [1], doped perovskite oxide such as SrZrO3 [2] and SrTiO3 [3], organic materials [4], and binary metal oxides such as NiO [5], TiO2 [6], ZrO2 [7], CuxO [8], and even doped SiO2 [9]. Among all these candidates, binary transition metal oxides excel the others due to their simple structure, easy fabrication process and compatibility with the complementary metal-oxide semiconductor (CMOS) technology [10]. Although HfO2 films are considered to be the promising gate dielectric in advanced CMOS devices, its resistive switching behavior is not fully explored, except for its unipolar switching behavior [11]-[12], i.e., turning ON and OFF occurs with the same voltage polarity. In our previous work [13], we studied the resistive switching characteristics of zirconium oxide embedded with ultrathin Au layer (with Au doping) and demonstrated that the intentionally introduced Au in ZrO2 films can significantly improve the device yield. Au atoms, unfortunately, may be fatal for the integration with CMOS devices.

In this work, we report the bipolar resi