The effect of embedding a thin layer of a polymer on resistive switching characteristics for Au/CdSe/Au structure

The phenomena of resistance random access memory (RRAM) depending on the altering of resistance between at least two values has been found in materials such as transition metal oxides, some semiconductors or insulators materials, named as resistive switching. The developments on RRAM have been started due to its low power consumption, simple structure, high-density, high – speed resistive switching, impressive retention with small-feature size. Regardless of the wide-ranging research, basic switching conduction mechanisms of the resistive memory structures are basically depending on the certain special materials. To improve the current structure performance, the Cellulose Acetate as a polymer was added to the active layer (cadmium selenide CdSe). The polymer material was used to form the second active coating to construct the Au/CdSe/polymer/Au as new structure. This material may enhance the cell performance by increasing the charges traps. This procedure leads to increasing resistance ratio (Rratio) and decreasing the working voltages of structure. A spin coating apparatus was used to coating the polymer layer on CdSe. The glass was used as a substrate and the first active layer deposited under vacuum by thermal evaporating system. The cell was sandwiched between the two electrodes in the same materials (Au) which deposited also under the same system. Bipolar resistive switch, in this memory structure, is observed in its switching operation. The zone of the upper electrode (Au) has a significant affect upon the resistive performance. This influence is became further in the big upper electrode zone (TEL=13.5mm2) where the high-resistance (HRS) are inversely related to the upper electrode zone (A). This occurs inducing more traps in case TEL (hanging sentence). Finally, the (Rratio) is directly proportional with the electrode zone (A). The compliance current (Icc=30mA) are used for protecting the structure from the damage. The current structure has many properties, such as Vset = 3.9V, VReset = -1.9V and Rratio about 176 in case of TEL. We conclude from this research that the embedment of a thin layer of a polymer which have been used in this research are improving the high density, enhancing high speed with low cost as well.