Investigation of a New Memory Technology

The Conductive Bridging Random Access Memory (CBRAM) technology is a new memory technology that is based on a solid electrolyte. To evaluate the potential of this resistive switching technology to be applied in integrated memories an experimental examination is performed. The experiments are divided in experiments that investigate the physics of the CBRAM technology and experiments that examine the characteristics of the CBRAM technology as memory technology. To analyze the analogy of the CBRAM technology and the electrochemical cell a photocurrent experiment is elaborated. The dependencies of the photocurrent on area, temperature, wavelength and voltage are given and explained by a charged double layer as it is formed in electrochemical cells. The dependence of the switching speed on the switching voltage is discussed and a model of the switching process, depending on the electrode kinetics at the electrode/electrolyte interface, is developed. To investigate a characteristic of the CBRAM technology as memory device the data retention is examined for a period of 1.5 10 7 s. For different write currents the CBRAM technology is demonstrated to be set to different resistance levels. This characteristic can be used to store more than one bit in a single memory cell. An experiment showing the stability of four levels, corresponding to two bits, is presented. The scalability of the CBARM technology is examined by means of a conductive Atomic Force Microscopy experiment, inducing a conductive path by a 40 nm tip. Measurements of passive samples with dimensions in the same range are presented, showing the scalability potential of the examined technology. To analyze the switching performance and the endurance of the CBRAM technology integrated circuits are conceived. Further experiments examine the operation temperature range and the distribution of the switching parameters.