Multi-channel Precision Voltage Source for Experiments on Quantum Dots

To realize precise control of single quantum dots (Qdots) device, the high-performance bias source play the key role. In this paper, the 16-channel high precision voltage bias source prototype for Qdots device with 18-bit resolution was designed. The prototype was made and its performance was tested. The short time fluctuations can reach 50μV. The up-step and the down-step response time can achieve less than 3μs. The stability, linearity and setting time of the bias source exhibits good performance. What's more, the voltage bias source can be controlled by local and online. The results show that it is one effective and feasible topology for the high precision voltage bias source in Qdots device application.

Bottom Electrode Properties and Electrical Field Cycling Effects on HfOx based Resistive Switching Memory Device

The continuously growing demands in high-density memories drive the rapid development of advanced memory technologies. In this work, we investigate the HfOx-based resistive switching memory (ReRAM) stack structure at nanoscale by high resolution TEM (HRTEM) and energy dispersive X-ray spectroscopy (EDX) before and after the forming process. Two identical ReRAM devices under different electrical test conditions are investigated. For the ReRAM device tested under a regular voltage bias, material redistribution and better bottom electrode contact are observed. In contrast, for the ReRAM device tested under an opposite voltage bias, different microstructure change occurs. Finite element simulations are performed to study the temperature distributions of the ReRAM cell with filaments formed at various locations relative to the bottom electrode. The applied electric field as well as the thermal heat are the driving forces for the microstructure and chemical modifications of the bottom electrode in ReRAM deceives.