Electric Pulse Induced Resistance Change Research Articles

Electric pulse induced impedance and material degradation in IC chip packaging

A method for measurement of electric circuit conduction path by Scan Electron Microscopy (SEM) has been developed. It shows that current conducts through the whole surface layer of solder joints when subjected to high frequency pulse loadings, but only half of the surface layer when subjected to AC loading. The Electrical Pulse Induced Resistance Change (EPIR) profile of a symmetric solder bump thin film structure of a typical IC chips packaging is studied. EPIR is found to be frequency, duty factor and current density dependent. An average current density model is proposed to approximate duty factor and the current density induced EPIR effects.

Observation of an EPIR Effect in Nd1−xSrxMnO3 Ceramics with Secondary Phases

Nd1−xSrxMnO3 (x = 0.3, 0.5) ceramics containing a secondary phase are synthesized by high-energy ball milling and post heat-treatment method. The 4-wire and 2-wire measuring modes are used to investigate the transport character of the grain/phase boundary (inner interface) and electrode-bulk interface (outer interface), respectively, and the results indicate that there is a similar nonlinear I–V behaviour for both of the inner and outer interfaces, however, the electric pulse induced resistance change (EPIR) effect can only be observed at the outer interface.

Multi-mode bipolar resistance switching in CuxO films

Electric pulse induced resistance change has been studied in the CuxO binary oxide systems for application to resistive random access memory. Binary transition metal oxides have typically shown unipolar switching, however, this has led to resistance states that have been somewhat erratic. We address here bipolar resistance switching (regular and reversed polarity) in thin film CuxO samples. I-V measurements at different temperatures showed strong evidence for a metallic bulk filament formation under application of an initial forming electric pulse. After forming, Set and Reset states can be controlled by changing positive and negative pulse amplitudes, but show two distinct resistance change regions: (i) resistance states from 20 Ω to 40 Ω with reversed polarity; and (ii) resistance states from 150 Ω to 8,000 Ω with regular polarity. A highly stable reversed polarity bipolar switching regime under application of low amplitude pulses and pulse width of 200 nsec is achieved, and a model for the switching mechanisms based on Cu+ ion motion in the interface region between the metallic filament and the top electrode is developed.

Resistance switching effect in LaAlO3/Nb-doped SrTiO3 heterostructure

The authors report on the fabrication and elec- tronic transport property of LaAlO3/Nb-doped SrTiO3 het- erostructure. The current-voltage curves of this heterostruc- ture show hysteresis and a remarkable resistance switch- ing behavior, which increase dramatically with decreasing temperature. Multiresistance states were realized by voltage pulses with different amplitudes and polarities and the ra- tio of the electrical pulse induced resistance change is larger than 10 4 . More interestingly, the relaxation of junction cur- rent after switching follows the Curie-von Schweidler law J ∝ t −n with an exponential increase of n with temperature. The results were discussed in terms of the trap-controlled space charge limited conduction process via defects near the interface of the heterostructure.

Electric-pulse-induced resistance change in Ba0.5Sr0.5Co0.2Fe0.8O3 thin films

Five-component perovskite Ba0.5Sr0.5Co0.2Fe0.8O3 (BSCFO) thin films are reported to have polarized electrical-pulse-induced resistance (EPIR) change at room temperature. Such an EPIR change is attributed to a combined effect of the resistance change in the Schottky barrier and the oxygen ion/vacancy movement near the interface. In the BSCFO, the lower threshold voltage of the electric pulse that leads to nonvolatile resistive changes is closely related to its higher oxygen permeability.

Electric pulse induced resistance change effect in manganites due to polaron localization at the metal-oxide interfacial region

Combining pulse-probe measurements as well as local transport measurements in an electron microscope system by a simultaneous monitoring of the structural changes, we show that the nonvolatile electric pulse induced resistance change in Ca-doped praseodymium manganite is related to a polaron order-disorder transition, modified by electronic band bending in the vicinity of an interface to a metallic electrode. A pronounced resistance change requires a critical distance between the two electrode and/or oxide interfaces to form an insulating incommensurate polaron-ordered phase during the initialization of the device. Based on these observations, a qualitative model for the electronic structure of the metal-oxide interface is developed.

A MICROSCOPIC ANALYSIS ON THE ELECTRICAL PULSE INDUCED RESISTANCE CHANGE EFFECT

ABSTRACT We have carried out microscopic resistance profile measurements by scanning probe microscopy (SPM) and model analyses on a symmetric thin-film electrical pulse induced resistance change (EPIR) device having a Pr0.7Ca0.3MnO3(PCMO) active layer. The film morphology and surface potential distribution has been examined by atomic force microscopy (AFM) and surface scanning Kelvin probe microscopy (SKPM). Resistance distribution profiles across the device indicate contribution to the resistance switching from three parts of the device: the two PCMO interface regions within ∼1–3 μ m around the metal electrode/PCMO contacts, and the bulk PCMO material. Such an EPIR device showed a symmetric resistance switching behavior under electric pulsing at room temperature. This research indicates that the EPIR device may be used as a nonvolatile resistive random access memory (RRAM) device with different operation modes by controlling electric pulse voltage. The result is also important for understanding the resistance switching behavior in the EPIR device.

Evidence for an Oxygen Diffusion Model for the Electric Pulse Induced Resistance Change Effect in Transition-Metal Oxides

Electric-pulse induced resistance hysteresis switching loops for Pr0.7Ca0.3MnO3 perovskite oxide films were found to exhibit an additional sharp "shuttle tail" peak around the negative pulse maximum for films deposited in an oxygen-deficient ambient. The resistance relaxation in time of this "shuttle tail" peak as well as resistance relaxation in the transition regions of the resistance hysteresis loop show evidence of oxygen diffusion under electric pulsing, and support a proposed oxygen diffusion model with oxygen vacancy pileup at the metal electrode interface region as the active process for the nonvolatile resistance switching effect in transition-metal oxides.

A study of the symmetry properties and multi-state nature of perovskite oxide-based electrical pulse induced resistance-change devices

A new symmetric two-terminal non-volatile electrical pulse induced resistance-change (EPIR) device is fabricated in the Pr0.7Ca0.3MnO3 (PCMO) materials system and analysed. Two actual devices of somewhat different construction are tested. Both consist of two similar half-parts, characterized by similar resistance versus pulse voltage hysteresis loops, which are reversely connected together in series forming a reflection symmetric device. Even though the devices are as physically symmetric as possible, they are found to exhibit resistance-switching under the application of voltage pulses of different amplitude and of different polarities. A symmetric model of the above device is proposed, and its analysis confirms the features noted above. The switching is history dependent and shows multi-intrinsic state resistance switching, which is very useful for developing future multi-bit EPIR devices.

Direct resistance profile for an electrical pulse induced resistance change device

We report the direct microscale resistance profile measurements on a symmetric thin-film electrical pulse induced resistance change (EPIR) device composed of a Pa0.7Ca0.3MnO3 (PCMO) active layer, using surface scanning Kelvin probe microscopy. The resistance switching is found to be an integration of the resistance changes from three parts of the device: the two interface regions within ∼1–3μm of the electrical contacts, and the bulk PCMO material. Such a symmetric EPIR device showed a “table leg” resistance switching hysteresis loop under electric pulsing at room temperature. The symmetric EPIR device may be used as a resistive random access memory nonvolatile memory device with different operation modes by controlling electric pulse voltage.