Ru Layer Research Articles

Ru Passivation Layer Enables Cu-Cu Direct Bonding at Low Temperatures with Oxidation Inhibition.

Stacking semiconductor chips allows for increased packing density within a given footprint and efficient communication between different functional layers of the chip, leading to higher performance, improved speed, and reduced power consumption. In such vertical stacking, achieving homogeneous electrical and mechanical bonding between heterogeneous chips is crucial, which is termed Cu to Cu direct bonding (CCDB) technology. However, conventional CCDB required a high temperature of over 250 °C to allow Cu diffusion and a vacuum condition for inhibiting Cu oxidation, limiting its practical utilization. Here, we propose that the covering of the Ru layer enables a reliable CCDB as low as 200 °C without concerns regarding oxidation. The bonding strength was as high as 2.24 MPa, and it was endurable at the -45 and 125 °C temperature cycle test for 500 cycles. Through microscopic analysis, we have identified that Cu diffuses through the intercluster boundaries of the Ru layer and moves to the surface, and these atomic Cu ions are recrystallized at the bonding interface, enabling stable bonding at lower temperatures. Specifically, we observed a trade-off between Cu diffusion distance and oxidation inhibition capability depending on the thickness of Ru and found that a 6 nm-thick Ru is optimal, balancing these factors.

Ru Decoration By PEALD for Bifunctional Oxygen Electrocatalysis in Solid Oxide Cells

Solid oxide cells (SOCs) are electrochemical devices that have garnered significant attention due to their high efficiency, fuel flexibility, and reversibility for operation in both fuel cell and the electrolysis modes. However, the relatively high operating temperature (typically > 800 °C) required presents various challenges such as fast degradation, high operating costs, and slow start-up. To overcome these issues, significant efforts have been made to decrease the operating temperature, but this causes a dramatic decrease in performance due to the low catalytic activity of typical electrode materials. One strategy to increase the catalytic activity is to introduce highly active nanoparticles onto a conventional electrode backbone, but while noble metals such as Ru and Ir have been utilized as oxygen evolution reaction (OER) catalysts, their widespread application in SOECs is hindered by their high cost and limited availability.In this presentation, we demonstrate a highly effective approach to enhance air electrode performance through the deposition of an ultrathin layer of metallic Ru, as thin as ∼7.5 Å, onto (La0.6Sr0.4)0.95Co0.2Fe0.8O3-δ (LSCF) using plasma-enhanced atomic layer deposition (PEALD). The Ru-decorated cell exhibited a current density of 656 mA cm–2 at 1.3 V, significantly outperforming a bare cell (440 mA cm–2 at 1.3 V). The decorated cell also showed a largely enhanced cell durability, which is ascribed to the beneficial role of SrRuO3 that emerges from the reaction between PEALD-based Ru and surface-segregated Sr species, in suppressing Sr segregation and maintaining favorable oxygen desorption kinetics. Further, the PEALD Ru coating on LSCF also reduces the resistance to the oxygen reduction reaction (ORR), highlighting the bifunctional electrocatalytic activities for reversible fuel cells. When the LSCF electrode of a test cell is decorated with ∼7.5 Å of the Ru overcoat and tested in fuel cell mode at 700 °C, this results in a current density of 656 mA cm-2 at 1.3 V in electrolysis mode and a peak power density of 803 mW cm-2, corresponding to an enhancement of 49.1% and 31.9%, respectively, compared to the pristine cell.

Stress, reflectance, and stability of Ru/Be multilayer coatings with Mo interlayers near the 11 nm wavelength.

The stress, reflectance, and temporal stability of Ru/Be multilayer mirrors, both with and without Mo interlayers, were studied. A Ru/Be MLM was found to have zero stress at a Ru layer thickness-to-period ratio of γ ∼ 0.4. By adding Mo interlayers to both interfaces, it is possible to achieve a record-high reflectance (R > 71%) at a wavelength close to 11 nm while maintaining near-zero stress levels. A Ru/Be MLM with Mo interlayers at both interfaces also demonstrates high temporal reflectance stability. Ru/Be MLMs may be of interest for the next-generation projection lithography at a wavelength of 11.2 nm.

Effect of Potassium Ferrocyanide on CMP Performance of Ruthenium in H2O2-based Slurries

As feature size of integrated circuits develops to 7 nm, ruthenium is considered the preferred material to replace traditional Ta/TaN barrier layers. Ruthenium can be electroplated without the need for copper seed crystal layers. However, the removal of the ruthenium barrier layer during the polishing process must be addressed. Therefore, this article studies the promoting effect of potassium ferrocyanide (K4Fe(CN)6) and hydrogen peroxide (H2O2) containing silicon slurries on the rate of ruthenium chemical mechanical polishing. Experiments have shown that the polishing rate of ruthenium is significantly improved by the combined action of K4Fe(CN)6 and H2O2. The stronger hydroxyl radicals is the main factor in achieving a high Ru polishing rate, which accelerates the dissolution and removal of Ru layers by converting the hard Ru layer into softer RuO2 and RuO3 oxide layers. The dependencies of the chemical properties (such as electrochemical impedance spectroscopy and surface morphology) proved that the CMP mechanism using Fenton reaction principally performs chemical oxidation and etching dominant CMP simultaneously. This study is expected to provide ideas and insights for the development and design of a new alkaline polishing solution for ruthenium, which is beneficial for the wider application of ruthenium in the field of integrated circuits.

Wafer-scale development, characterization, and high temperature stabilization of epitaxial Cr2O3 films grown on Ru(0001).

This work outlines conditions suitable for the heteroepitaxial growth of Cr2O3(0001) films (1.5-20nm thick) on a Ru(0001)-terminated substrate. Optimized growth is achieved by sputter deposition of Cr within a 4mTorr Ar/O2 20% ambient at Ru temperatures ranging from 450 to 600 °C. The Cr2O3 film adopts a 30° rotated honeycomb configuration with respect to the underlying Ru(0001) substrate and exhibits a hexagonal lattice parameter consistent with that for bulk Cr2O3(0001). Heating to 700 °C within the same environment during film preparation leads to Ru oxidation. Exposure to temperatures at or above 400 °C in a vacuum, Ar, or Ar/H2 3% leads to chromia film degradation characterized by increased Ru 3d XPS intensity coupled with concomitant Cr 2p and O 1s peak attenuations when compared to data collected from unannealed films. An ill-defined but hexagonally well-ordered RuxCryOz surface structure is noted after heating the film in this manner. Heating within a wet Ar/H2 3% environment preserves the Cr2O3(0001)/Ru(0001) heterolayer structure to temperatures of at least 950 °C. Heating an Ru-Cr2O3-Ru heterostacked film to 950 °C within this environment is shown by cross-sectional scanning/transmission electron microscopy (S/TEM) to provide clear evidence of retained epitaxial bicrystalline oxide interlayer structure, interlayer immiscibility, and epitaxial registry between the top and bottom Ru layers. Subtle effects marked by O enrichment and O 1s and Cr 2p shifts to increased binding energies are noted by XPS in the near-Ru regions of Cr2O3(0001)/Ru(0001) and Ru(0001)/Cr2O3(0001)/Ru(0001) films after annealing to different temperatures in different sets of environmental conditions.

Photoexcited Hot Electron Catalysis in Plasmon-Resonant Grating Structures with Platinum, Nickel, and Ruthenium Coatings.

We report the electrochemical potential dependence of photocatalysis produced by hot electrons in plasmon-resonant grating structures. Here, corrugated metal surfaces with a period of 520 nm are illuminated with 785 nm wavelength laser light swept as a function of incident angle. At incident angles corresponding to plasmon-resonant excitation, we observe sharp peaks in the electrochemical photocurrent and dips in the photoreflectance consistent with the conditions under which there is wavevector matching between the incident light and the spacing between the lines in the grating. In addition to the bare plasmonic metal surface (i.e., Au), which is catalytically inert, we have measured grating structures with a thin layer of Pt, Ru, and Ni catalyst coatings. For the bare Au grating, we observe that the plasmon-resonant photocurrent remains relatively featureless over the applied potential range from -0.8 to +1.2 V vs NHE. For the Pt-coated grating, we observe a sharp peak around -0.3 V vs NHE, three times larger than the bare Au grating, and near complete suppression of the oxidation half-reaction, reflecting the reducing nature of Pt as a good hydrogen evolution reaction catalyst. The photocurrent associated with the Pt-coated grating is less noisy and produces higher photocurrents than the bare Au grating due to the faster kinetics (i.e., charge transfer) associated with the Pt-coated surface. The plasmon-resonant grating structures enable us to compare plasmon-resonant excitation with that of bulk metal interband absorption simply by rotating the polarization of the light while leaving all other parameters of the experiment fixed (i.e., wavelength, potential, electrochemical solution, sample surface, etc.). A 64X plasmon-resonant enhancement (i.e., p-to-s polarized photocurrent ratio) is observed for the Pt-coated grating compared to 28X for the bare grating. The nickel-coated grating shows an increase in the hot-electron photocurrent enhancement in both oxidation and reduction half-reactions. Similarly, Ru-coated gratings show an increase in hot-electron photocurrents in the oxidation half-reaction compared to the bare Au grating. Plasmon-resonant enhancement factors of 36X and 15X are observed in the p-to-s polarized photocurrent ratio for the Ni and Ru gratings, respectively.

Effects of pyrazine and its derivatives as inhibitors on copper film chemical-mechanical polishing properties for ruthenium-based copper interconnect

During the one-step chemical mechanical polishing (CMP) process of ruthenium (Ru)-based copper (Cu) interconnected Cu films, a high Cu removal rate (RR) while maintaining a near zero Ru RR should be required to ensure a flat surface. The most ideal and difficult part of the CMP process is how to achieve rapid removal of Cu film without affecting Ru layer. Corrosion inhibitors in the slurry fulfill a significant function in controlling RR and improving the surface quality. Therefore, in this study, pyrazine (PY) and its derivative aminopyrazine (AP) as cost-effective and harmless corrosion inhibitors for Ru-based Cu interconnected Cu film CMP were investigated under weakly alkaline conditions (pH=8.5). First, through the utilization of experimental and theoretical methods, a systematical analysis was conducted to assess the corrosion inhibition effects of AP and PY, and it was found that the corrosion inhibition effect of AP was stronger than that of PY. Then, the adsorption and inhibition mechanism of AP on Cu/Ru surface were analyzed by electrochemical testing and X-ray photoelectron spectroscopy (XPS), and the adsorption behavior of AP molecules on the Cu (111) surface was investigated at the molecular level using quantum chemical methods. Finally, tests on Cu patterned wafers showed that the combination of 0.5 wt% AP and 0.5 wt% sarcosine (Sar) proved to be successful in effectively rectifying the step height on the Cu patterned wafer. At the same time, a high RR of 7281 Å /min, a low surface root mean square deviation (Sq) of 1.35 nm in 10 μm×10 μm region and a low static etching rate (SER) of 1015 Å /min were obtained with the synergistic effect of AP and Sar. This outcome holds substantial theoretical implications for advancing the formulation of low-node Cu film slurry.

Enhanced orbital torque efficiency in nonequilibrium Ru50Mo50(0001) alloy epitaxial thin films

Epitaxial thin films of fully nonequilibrium hcp-Ru50Mo50(0001) nanoalloys were prepared as a chemically disordered alloy, in which the intrinsic spin Hall effect is expected to be negligible. Structural analyses confirmed the epitaxial growth and atomic scale alloying of the films. In contrast to a tiny torque efficiency (ξDL) of ∼0.4% for Ru50Mo50/CoFeB, the ξDL for the Ru50Mo50/Ni heterostructure reached ∼30% with a long-range relaxation length. The apparent dependence of ξDL on the ferromagnetic layer can be attributed to the orbital Hall effect (OHE). Interestingly, a smaller ξDL was observed for Ru/Ni, suggesting that the nonequilibrium Ru50Mo50 enhances its OHE. Furthermore, the enhanced ξDL is maintained by inserting a Ru layer between the Ru50Mo50 and Ni layers, showing orbital transport through Ru. This finding illustrates potential applications of nonequilibrium nanoalloy films in spin orbitronics and contributes to getting insights into the understanding of the interrelationships between nanostructures and orbital transport properties.

Effective degradation of polystyrene microplastics by Ti/La/Co-Sb-SnO2 anodes: Enhanced electrocatalytic stability and electrode lifespan

Microplastics have been identified as an emerging pollutant that poses a risk to the aquatic environment, and it is a challenge to find a suitable removal process. Electrocatalytic oxidation (ECO) technology has shown promising performance in removing various persistent organic pollutants. In this study, we prepared a new anode for removing polystyrene microplastics (PS MPs) by ECO. Ti/La-Sb-SnO2 electrodes doped with the rare earth element La as the active layer were synthesized to enhance the electrocatalytic activity. The lifespan of the electrode was improved by doping Mn, Co, or Ru as an intermediate layer modification between the titanium (Ti) substrate and the La-Sb-SnO2 active layer, respectively. The experimental results indicated that the addition of three types of intermediate layers led to different degrees of decrease in the catalytic activity of the electrode and the degradation performance of PS MPs. The addition of the Co intermediate layer had a negligible effect on the catalytic activity and performance of the Ti/La-Sb-SnO2 anode for PS degradation. In addition, the electrode lifespan with Co intermediate layer was significantly prolonged, which was 4.54, 2.38, and 1.19 times higher than the electrode without intermediate layer and the electrode with Ru and Mn intermediate layer, respectively. Therefore, Co was determined to be the optimal choice as the intermediate layer, and the production technique for the Ti/La/Co-Sb-SnO2 anodes was carefully adjusted. The degradation efficiency of PS MPs was optimized at a heat treatment temperature of 400 °C and a Sn: Co material ratio of 5:1, with a removal rate of 28.0 %. The ECO treatment also resulted in more pronounced changes in the structure and functional groups of the MPs. Various alkyl cleavage and oxidation products were detected after the treatment, suggesting that the oxidant (hydroxyl radicals) strongly interacted with the MPs, leading to their degradation. Overall, this work provided a new insight into removing MPs in water through the use of modified electrodes.

A study of Ru–Cr protective coatings for precision glass molding

This study evaluates the performance of Ru–Cr nanolayers used as protective coatings for precision glass molding (PGM) applications. Because the direct growth of Cr-oxide from Cr at high temperatures does not yield a dense oxide scale, Ru is employed as a diffusion barrier to stabilize the growth process. The fabricated coatings were subjected to annealing at 750 °C for different durations, with the coverage of aluminosilicate glass (ASG) pieces. During the annealing process, the outward diffusion of Cr resulted in the formation of thin and stable chromium oxide (Cr2O3) films, which remained unadhered to the glass pieces. Therefore, the Ru–Cr bilayer is a cost-effective coating design to protect mold surfaces in PGM. Detailed analysis using transmission electron microscopy (TEM) revealed that while columnar grains with vertical grain boundaries facilitate the outward diffusion of Cr, a thick Ru layer can effectively hinder Cr diffusion leading to a stable oxide film at a high temperature. A diffusion-oxidation phase-field model quantitatively elucidates oxide film thickness dependence on Ru thickness (>600 nm). Thinner Ru layers (<600 nm) display limited Ru thickness influence and some metallic Cr content in the scales, causing incomplete densification.

Unleashing the Power of 2D MoS2: In Situ TEM Study of Its Potential as Diffusion Barriers in Ru Interconnects.

This study presents the utilization of MoS2 as a diffusion barrier for metal interconnects, in situ transmission electron microscopy (TEM) observations are employed for comprehensive understanding. The diffusion-blocking ability of MoS2 is discussed by the diffusion and phase transformation between Ru and Si via TEM diffraction and imaging. When the sample is heated to a high temperature such that MoS2 loses the ability to block the diffusion, Si diffuses through the MoS2 into the Ru layer, leading to the formation of Ru2Si3. Both multilayer and monolayer (1L) MoS2 exhibit exceptional diffusion-blocking ability up to 800 °C. Furthermore, plasma-treated 1L-MoS2 shows a slightly low diffusion-blocking temperature of 750 °C, while the dangling bonds in MoS2 improve the interfacial adhesion. These findings suggest that MoS2 holds great potential as a diffusion barrier for metal interconnects.

Ultralow Loading of Ru as a Bifunctional Catalyst for the Oxygen Electrode of Solid Oxide Cells.

The oxygen evolution reaction (OER) is a significant contributor to the cell overpotential in solid oxide electrolyzer cells (SOECs). Although noble metals such as Ru and Ir have been utilized as OER catalysts, their widespread application in SOECs is hindered by their high cost and limited availability. In this study, we present a highly effective approach to enhance air electrode performance and durability by depositing an ultrathin layer of metallic Ru, as thin as ∼7.5 Å, onto (La0.6Sr0.4)0.95Co0.2Fe0.8O3-δ (LSCF) using plasma-enhanced atomic layer deposition (PEALD). Our study suggests that the emergence of a perovskite, SrRuO3, resulting from the reaction between PEALD-based Ru and surface-segregated Sr species, plays a crucial role in suppressing Sr segregation and maintaining favorable oxygen desorption kinetics, which ultimately improves the OER durability. Further, the PEALD Ru coating on LSCF also reduces the resistance to the oxygen reduction reaction (ORR), highlighting the bifunctional electrocatalytic activities for reversible fuel cells. When the LSCF electrode of a test cell is decorated with ∼7.5 Å of the Ru overcoat, a current density of 656 mA cm-2 at 1.3 V in electrolysis mode and a peak power density of 803 mW cm-2 in fuel cell mode are demonstrated at 700 °C, corresponding to an enhancement of 49.1 and 31.9%, respectively, compared to the pristine cell.

Study of Synthetic Antiferromagnetic Nanostructures Based on CoFeB/Ru/CoFe

A study of the magnetic properties of synthetic antiferromagnetic nanostructures (SAF) has been carried out. In the SAF structure, two ferromagnetic layers separated by a nonmagnetic metal are coupled by the exchange RKKY interaction (Ruderman— Kittel—Kasuya—Yoshida), which has an oscillating character. The total magnetic moment of the SAF structure is minimal with an antiparallel configuration of the magnetization of the ferromagnetic layers, due to which the effect on the magnetic layers in the structure is reduced. The structures under study have a number of unique properties and are used in the elements of nonvolatile magnetoresistive memory, in magnetic field transducers, and in spin logic devices. The characteristics of the SAF of CoFeB/Ru/CoFe nanostructures with the Ru layer thickness corresponding to the second antiferromagnetic maximum are obtained. The magnetization reversal curves of SAF structures with Ru thickness of 2.1 nm, 2.3 nm and 2.5 nm have been studied. The optimal ratio of ferromagnetic layers was selected to reduce the magnetic moment of the SAF structure. A study of the effect of thermomagnetic treatment on the properties of the SAF nanostructure was carried out, which showed that there are no significant changes in the magnetization reversal, and the magnetic saturation field slightly increases. The curves of magnetization reversal of CoFeB/Ru/CoFe structures fixed by the antiferromagnetic layer are presented. In addition, magnetization reversal curves of spin-tunnel magnetoresistive nanostructures with an antiferromagnetic layer and a SAF structure are presented, and an analysis of the thermal stability of the structures with SAF is also carried out.

Hardmask engineering by mask encapsulation for enabling next generation reactive ion etch scaling

Miniaturization and scaling of semiconductor devices require development of innovative techniques to sustain advancements. A promising trend is the migration from 2D to 3D device architectures that necessitate fabrication of high-aspect-ratio narrow features through layers of different materials. Reactive ion etching can achieve this but poses unique challenges due to the requirement of etch chemistries capable of etching dissimilar materials with varying etch rates while maintaining high productivity. The choice of hardmask is also crucial, as it plays a critical role in determining efficacy of the etch process and the final shape of the feature being etched. To address these challenges, we introduce a new concept of hardmask engineering that involves a bilayer hardmask scheme consisting of a patterned conventional hardmask encapsulated with a thin layer of etch-resistant ruthenium (Ru) layer. Experimental results for etching multilayer stacks consisting of alternating pairs of SiO2 and Mo show that this engineered hardmask results in improved hardmask remaining and etch profile with smaller critical dimensions (CDs). Technology computer-aided design simulations with the Ru encapsulation layer on conventional carbon hardmask demonstrate increased poly-Si etch depth with reduced bow CD. This concept can be extended to any semiconductor nanofabrication step involving high-aspect-ratio etching where precise control of CDs is essential in the vertical direction.

Spatially Confined PdHx Metallenes by Tensile Strained Atomic Ru Layers for Efficient Hydrogen Evolution.

Hydride metallenes show great potential for hydrogen-related catalytic applications due to favorable electronic structures modulated by interstitial hydrogen atoms and large active surface areas of metallenes. Metallene nanostructures generally have compressive strain relative to bulk, which can affect both the stability and the catalytic behavior of hydride metallenes but in general cannot be controlled. Here, we demonstrate highly stable PdHx metallenes with a tensile strained Ru surface layer and reveal the spatial confinement effect of the Ru skin by multiple spectroscopic characterizations and molecular dynamics simulations. These PdHx@Ru metallenes with a 4.5% expanded Ru outer layer exhibit outstanding alkaline hydrogen evolution reaction activity with a low overpotential of 30 mV at 10 mA cm-2 and robust stability with negligible activity decay after 10,000 cycles, which are superior to commercial Pt/C and most reported Ru-based electrocatalysts. Control experiments and first-principles calculations reveal that the tensile strained Ru outer layer lowers the energy barrier of H2O dissociation and provides a moderate hydrogen adsorption energy.

Seedless electrodeposition of Cu thin films on ALD Ru diffusion barriers with different electrical properties

Seedless Cu electrodeposition was performed directly on 10 nm atomic-layer-deposited (ALD) Ru diffusion barrier layer for Cu interconnect application in microelectronic devices. N2 gas flow rate ratio of Ru ALD process was varied between 0.24 and 0.86 to manipulate the electrical property of resultant ALD Ru layers. The nucleation and growth characteristic of Cu on ALD Ru changed depending on the electrical resistivity of ALD Ru layer under the potentiostatic deposition of Cu in an additive-free Cu-ammonia-citrate (Cu-NH3-Cit) electrolyte. As a result, a less resistive ALD Ru layer, which was formed at a lower N2 gas flow rate ratio, led to a lower electrical resistivity of Cu thin film.

CMOS-compatible self-aligned 3D memristive elements for reservoir computing systems

Neuromorphic capabilities of a self-aligned complementary metal-oxide-semiconductor compatible W/WOx/HfO2/Ru cell in a 3D vertical memristive structure were investigated. We show that the device exhibits nonfilamentary forming-free multilevel resistive switching with gradual resistance change. In addition, the poor retention of a low resistance state allows integration of these structures in architectures that require short-term memory characteristics such as reservoir computing systems. The ability of the device to rely on the temporal sequence of the stream was tested with the digit recognition task. Since a WOx layer was obtained by thermal oxidization and HfO2 and Ru layers were grown by atomic layer deposition methods, the device is suitable for high-density systems with high connectivity within a neural network.

Interdiffusion and oxidation behaviour of Pt/Ru modified Ni–30Al–0.3Dy coating on Ni3Al-based superalloy

ABSTRACT A high purity of Ru or Pt was deliberately deposited as a middle layer between an alumina-forming Ni–30Al–0.3Dy coating and a Ni3Al-based single-crystal superalloy. It was found that the Ru modified Ni–30Al–0.3Dy coating effectively suppressed the interdiffusion between the coating and the substrate and inhibited the precipitation of topologically close-packed (TCP) phases which impaired the mechanical properties of the superalloy. The 1100°C annealing and oxidation tests suggested that, different from Pt, Ru restricted the inward diffusion of Al from the coating to the substrate, thereby hindering the interdiffusion. And the existence of Ru layer can simultaneously improve the oxidation resistance of the coating.

Study of oxidation behaviour of Ruthenium thin film after thermal annealing in oxygen environment

In the present study, 20 nm thick Ru film ion beam sputtered on Si substrate is annealed at different temperatures ranging from 100 °C to 600 °C for 2 hours in an oxygen environment. The sample was characterized by grazing incidence x-ray reflectivity and grazing incidence x-ray diffraction techniques that revealed that there is no oxidation of Ru below 400 °C in 150 standard cubic centimetre O2 flow environment. At 400 °C, the oxidation of the Ru thin film starts and at 500 °C both Ru and RuO2 phases co-exists. At higher temperature (600 °C), the Ru thin film oxidized into RuO2 phase and an intermixed layer of Ru and Si at the film substrate interface is revealed.

Bi-polaron Transport and Magnetic Field Induced Pauli Spin Blockade in Redox-Active Molecular Junctions.

We report the bi-polaron transport and magnetic field induced Pauli spin-blockade in solid-state molecular junctions (MJs) evidenced by a positive magnetoresistance (MR). The junction was made of thin layers of redox-active ruthenium polypyridyl-oligomers Ru(tpy)2 sandwiched between conducting amorphous carbon (a-C) electrodes. The redox-active Ru(tpy)2 molecule, which enables small polaron and deep traps in the charge transport of the Ru(tpy)2 MJ as revealed by the temperature-dependent current-voltage response, leads to the formation of the bi-polaron and magnetic field induced Pauli spin blockade, resulting into the MR. At the meantime, the reliable and controllable device performance renders a rigid thickness-dependent MR evolution. The bi-polaron transport revealed in our study underscores the importance of the multi-particle transport by molecular design in MJs and laid the foundation for magnetic-electronic function in molecular-scale devices.