A Pt/TiO₂/Ti Schottky-type selection diode for alleviating the sneak current in resistance switching memory arrays

Abstract

This study examined the properties of Schottky-type diodes composed of Pt/TiO(2)/Ti, where the Pt/TiO(2) and TiO(2)/Ti junctions correspond to the blocking and ohmic contacts, respectively, as the selection device for a resistive switching cross-bar array. An extremely high forward-to-reverse current ratio of approximately 10(9) was achieved at 1 V when the TiO(2) film thickness was 19 nm. TiO(2) film was grown by atomic layer deposition at a substrate temperature of 250 degrees C. Conductive atomic force microscopy revealed that the forward current flew locally, which limits the maximum forward current density to < 10 A cm(-2) for a large electrode (an area of approximately 60 000 microm(2)). However, the local current measurement showed a local forward current density as high as approximately 10(5) A cm(-2). Therefore, it is expected that this type of Schottky diode effectively suppresses the sneak current without adverse interference effects in a nano-scale resistive switching cross-bar array with high block density.

A plasma-treated chalcogenide switch device for stackable scalable 3D nanoscale memory

“…Furthermore, both components will be required to be compatible with technologies such as threedimensional (3D) cell stacking, multi-level cell, endurance and scaling for future memory and switch devices 1,2 . Resistive random access memory has been considered to be one of the most promising candidates to overcome scaling limits of the conventional memory due to its scalability, data retention (nonvolatility), fast switching speed and low power consumption [3][4][5][6][7][8][9][10][11][12][13][14][15] . In a high-density memory system such as dynamic random access memory, a select device is required to suppress sneak current paths 3,8,9 .…”

Rate limiting step for the switching kinetics in Cu doped Ge0.3Se0.7 based memory devices with symmetrical and asymmetrical electrodes

“…23 Hence, in the case of bipolar-type memory cells, more complicated varistor type-elements with specific degrees of non-linearity (high current density and threshold voltage) are required at both polarities. 23 Recently, different concepts such as complementary resistance switches, 24,25 inherent rectifying resistance switching elements, 26 and Schottky interface based selection devices 27 have also been investigated to solve crosstalk problem for bipolar resistance switching based crossbar arrays.…”

Comparator and half adder design using complementary resistive switches crossbar

“…When three voltage variables are applied to T 1 , T 2 , T 3 respectively, the next states, and its present states S 1 , S 2 are described by (2). The output M and inputs T 1 , T 2 , T 3 , and present states S 1 , S 2 is described by (3).…”

“…However, sneak path problem limits the size of the arrays and increases their power consumption. To solve the sneak path problem, various solutions were proposed, such as P-N junction type diode [2], Schottky type diode [3], complementary resistive switches (CRS) [4]. Among these proposed solutions, CRS is suitable for reducing parasitic current and making the application of large passive crossbar arrays feasible [4,5].…”