Electrical and reliability characteristics of copper-doped carbon (CuC) based resistive switching devices for nonvolatile memory applications

Abstract

We have investigated copper-doped carbon (CuC) as a new solid-state electrolyte material for resistive switching devices. Compared with CuS electrolytes, CuC devices demonstrate good memory characteristics such as a high resistance ratio of over two orders, higher operation voltage, and high temperature retention characteristics. Using 1000 cell array devices, we have also confirmed uniform distributions of resistance and switching voltages. Both high and low resistance states showed negligible degradation of resistance for over 104 s at 85 °C, confirming good retention characteristics.

Nanoscale Bipolar and Complementary Resistive Switching Memory Based on Amorphous Carbon

“…Devices with a fast-diffusing metal such as Cu, Ag, and Au on top of a-C have been reported to exhibit the bipolar resistive switching behavior [19]- [21]. The bipolar resistive switching behavior is the result of electrochemical metallization of the conductive filaments, similar to the conductive-bridge resistive memory [13]- [15], [19]- [21]. Bipolar switching is more controllable than unipolar switching as the SET and the RESET processes occur at opposite voltage polarities.…”

“…The unipolar switching mechanism of a-C has been explained as the formation/rupture of the sp 2 carbon chain in the sp 3 carbon matrix, in which carbon is the monoatom for both the conductive filament and the insulating matrix. Devices with a fast-diffusing metal such as Cu, Ag, and Au on top of a-C have been reported to exhibit the bipolar resistive switching behavior [19]- [21]. The bipolar resistive switching behavior is the result of electrochemical metallization of the conductive filaments, similar to the conductive-bridge resistive memory [13]- [15], [19]- [21].…”

“…No atomic migration will happen in the CNT in the normal device operation region due to the high current-carrying capacity (> 10 9 A/cm 2 ) of the CNT [32]. Resistive switching is most likely to be caused by the precipitates from the top diffusing metal electrode to the a-C matrix [19]- [21]. The I-V curve of the LRS of a Au/a-C/CNT/Au cell shows an ohmiclike behavior with a slope of 1.1.…”

“…Amorphous carbon is a noncrystalline carbon allotrope in which a long-range crystalline order is not present. Different switching mechanisms for a-C have been proposed to explain the resistive change behavior, including thermochemical sp 2 carbon chain forming/rupture [17], [18], electrochemical metallization [19]- [21], and valence change [22], [23].…”

Mechanism for resistive switching in chalcogenide-based electrochemical metallization memory cells

“…3,4 Till now, a large number of ECM cells have been reported, employing various insulating materials such as chalcogenides, [5][6][7][8][9][10][11][12][13] oxides, [14][15][16][17][18][19][20][21][22][23][24] amorphous Si (Refs. 25 and 26) and C, [27][28][29][30] and organic materials. 31,32 For the RS mechanism of ECM cells, the most widely accepted hypothesis is as follows, 1-3 with Cu as the AE (anode) and Pt as the CE (cathode) metal: (i) anodic dissolution of Cu; (ii) drift of the Cu ions across the insulator film; (iii) reduction and electro-crystallization of Cu on the CE surface, leading to the formation of a conical filament with the base and the tip located at the cathodic and the anodic interfaces, and switching the cell ON; (iv) electrochemical dissolution at the weakest point along the length of the filament, i.e., near the anodic interface as a sufficient opposite polarity voltage is applied, switching the cell OFF.…”