STABLE RESISTIVE SWITCHING CHARACTERISTICS OF Al2O3 LAYERS INSERTED IN HfPO2 BASED RRAM DEVICES

Resistive switching random access memory (RRAM) has attracted extensive attention for next-generation nonvolatile memory application due to the merits of low power consumption, high speed operation, and high density integration. The resistive switching (RS) characteristics of various metal oxides have been studied. Among those materials, HfO2 is one of the appealing materials that had received considerable attention owing to a high dielectric constant, simple composition, and its standard CMOS processes compatibility. However, the thermal stability of HfO2 thin film is a serious issue for memory characteristics due to the low crystalline temperature. In this work, we utilized ALD growth HfO2 thin films with inserted different amount of Al2O3 layers as RS layer for crystallization and RS characteristics study. From the experimental results, the crystalline temperatures depend on the amount of inserted Al2O3 layers. By the way, the forming voltages were modulated by using different amount of Al2O3 layers inserted in HfO2 thin film, changed from 2.5 V (HfO2) to 4.1 V (Al2O3). Moreover, the device shows better resistive switching performance than pure HfO2 and pure Al2O3 devices, such as more stable operation voltage and higher resistive switching cycles (11000 cycles)