Cross-sectional Transmission Electron Microscopy Research Articles

Implementation of high-performance and high-yield nanoscale hafnium zirconium oxide based ferroelectric tunnel junction devices on 300 mm wafer platform

In this work, hafnium zirconium oxide (HZO)-based 100 × 100 nm2 ferroelectric tunnel junction (FTJ) devices were implemented on a 300 mm wafer platform, using a baseline 65 nm CMOS process technology. FTJs consisting of TiN/HZO/TiN were integrated in between metal 1 (M1) and via 1 (V1) layers. Cross-sectional transmission electron microscopy and energy dispersive x-ray spectroscopy analysis confirmed the targeted thickness and composition of the FTJ film stack, while grazing incidence, in-plane x-ray diffraction analysis demonstrated the presence of orthorhombic phase Pca21 responsible for ferroelectric polarization observed in HZO films. Current measurement, as a function of voltage for both up- and down-polarization states, yielded a tunneling electroresistance (TER) ratio of 2.28. The device TER ratio and endurance behavior were further optimized by insertion of thin Al2O3 tunnel barrier layer between the bottom electrode (TiN) and ferroelectric switching layer (HZO) by tuning the band offset between HZO and TiN, facilitating on-state tunneling conduction and creating an additional barrier layer in off-state current conduction path. Investigation of current transport mechanism showed that the current in these FTJ devices is dominated by direct tunneling at low electric field (E < 0.4 MV/cm) and by Fowler–Nordheim (F–N) tunneling at high electric field (E > 0.4 MV/cm). The modified FTJ device stack (TiN/Al2O3/HZO/TiN) demonstrated an enhanced TER ratio of ∼5 (2.2× improvement) and endurance up to 106 switching cycles. Write voltage and pulse width dependent trade-off characteristics between TER ratio and maximum endurance cycles (Nc) were established that enabled optimal balance of FTJ switching metrics. The FTJ memory cells also showed multi-level-cell characteristics, i.e., 2 bits/cell storage capability. Based on full 300 mm wafer statistics, a switching yield of >80% was achieved for fabricated FTJ devices demonstrating robustness of fabrication and programming approach used for FTJ performance optimization. The realization of CMOS-compatible nanoscale FTJ devices on 300 mm wafer platform demonstrates the promising potential of high-volume large-scale industrial implementation of FTJ devices for various nonvolatile memory applications.

Evaluation of Damage in Crystalline Silicon Substrate Induced by Plasma Enhanced Chemical Vapor Deposition of Amorphous Silicon Films

We evaluated damage to crystalline silicon (c-Si) induced by plasma enhanced chemical vapor deposition (PECVD) of hydrogenated amorphous silicon (a-Si:H). The damaged layer +-on the c-Si surface under the a-Si:H film was evaluated by lifetime measurements using the photoconductance method in conjunction with step etching. This damaged layer is approximately 2.8 nm and did not disappear by annealing at 200 °C for 30 min in the air atmosphere. The image from cross-sectional transmission electron microscope (TEM) observation also shows an area of contrast on the c-Si surface approximately 2.8 nm thick, which appears to be a damaged layer. Photoluminescence (PL) measurements revealed that this damage is a non-luminescent defect. We verified that the difference in H2 flow rate during the a-Si:H deposition has an effect on the depth of the damage penetration into the c-Si. We concluded that the H atom is the main cause of the damage introduced into c-Si during a-Si:H deposition by PECVD.

Photoluminescence characterization of GeSn prepared by rapid melting growth method

In this work, single crystalline GeSn on insulator (GSOI) were grown by rapid melting growth (RMG). The Sn content distribution along the strip was investigated, reaching to 7.8% near the end of the strip. The GeSn strip had high quality with no threading dislocations, as revealed by cross-sectional transmission electron microscopy (XTEM). Photoluminescence (PL) measurements along the strip were performed to check the indirect-direct bandgap transition Sn content of GeSn alloys. It was found the integrated PL intensity increased about 6.6 times for Sn content 0.86%–7.8%. For GeSn with Sn content 6.1%, the temperature-dependent PL shows that the energy difference between direct Γ-Γ valley and indirect L-Γ valley decreases due to the bandgap narrowing (BGN) effect, and the direct band transition gradually dominates the PL spectra as temperature increases. The temperature-dependent PL spectra have only one peak for GeSn with Sn content 7.8%, suggesting the direct bandgap property. These results indicate that GeSn grown by RMG is very promising for fabricating efficient Si based light sources.

Band-gap and strain engineering in GeSn alloys using post-growth pulsed laser melting

The pseudomorphic growth of Ge1−x Sn x on Ge causes in-plane compressive strain, which degrades the superior properties of the Ge1−x Sn x alloys. Therefore, efficient strain engineering is required. In this article, we present strain and band-gap engineering in Ge1−x Sn x alloys grown on Ge a virtual substrate using post-growth nanosecond pulsed laser melting (PLM). Micro-Raman and x-ray diffraction (XRD) show that the initial in-plane compressive strain is removed. Moreover, for PLM energy densities higher than 0.5 J cm−2, the Ge0.89Sn0.11 layer becomes tensile strained. Simultaneously, as revealed by Rutherford Backscattering spectrometry, cross-sectional transmission electron microscopy investigations and XRD the crystalline quality and Sn-distribution in PLM-treated Ge0.89Sn0.11 layers are only slightly affected. Additionally, the change of the band structure after PLM is confirmed by low-temperature photoreflectance measurements. The presented results prove that post-growth ns-range PLM is an effective way for band-gap and strain engineering in highly-mismatched alloys.

Warp-Free TEM Sample Preparation Methods Using FIB/SEM Systems.

Warping is a limiting factor when preparing transmission electron microscopy (TEM) samples using focused ion beam (FIB)/scanning electron microscope (SEM) systems. The conventional FIB sputtering process leaves at least one side of the lamella too thin to provide structural support to offset inherent stresses. As a result, warping can occur impacting imagining and reducing the potential size of lamellae. For example, capturing more than a few back-end metal layers in a 3 μm wide cross-section lamella can be difficult. Frequently, TEM analysts must perform multiple stage adjustments to analyze such a sample. In this paper, two methods are presented that enable FIB/SEM operators to prepare TEM samples where the thinned region of interest is surrounded by thick structures. As a result, these methods reduce warping and enable the fabrication of TEM lamellae not possible by conventional means. For example, these methods have been used to produce a 10 μm wide by 8 μm tall cross-section TEM sample that captured front-end transistors and 14 back-end metal layers. Furthermore, warping was so limited that only one alignment was needed by the TEM analyst to complete the imaging of the sample. The methods, called the horizontal bracing and window methods, make use of the deposition of low-Z amorphous films that are electron transparent in the TEM.

Magnetic properties of Fe soft magnetic composites with a double-insulating layer comprising Fe3O4 and silicone resin

In this study, we suggest a rotating closed reaction system for oxidizing Fe powder at 500 ℃. This rotation leads to the homogeneous oxidation of large amounts of Fe powder. The analysis of the oxygen content in the oxidized Fe powder shows that all oxygen gas supplied to the closed system is consumed for the oxidation of Fe powder. This indicates that the thickness of the Fe3O4 layer formed by oxidation increases proportionally with the amount of oxygen gas supplied to the reactor. It was observed that the loss of the toroidal core decreased as the thickness of the Fe3O4 layer increased. The change in hysteresis loss was negligible compared with the change in eddy current loss. The eddy current loss decreased from 364.2 W/kg to 139 W/kg (@ 1 T, 400 Hz) as the Fe3O4 layer thickened from 30 to 110 nm. Because the Fe3O4 layer did not provide sufficient insulation, another approach was attempted to coat the silicone resin (>1013 Ω∙cm) with a specific resistivity approximately 1015 times higher than that of Fe3O4 on the Fe3O4 layer. To observe this double-layer structure, a thermally evaporated Ni film was coated on top of the double-insulating layer. The energy-dispersive X-ray spectroscopy analysis of a cross-sectional transmission electron microscopy image showed that the Ni film successfully protected the silicone resin layer from the ion-beam irradiated during FIB sampling, making it possible to observe the double-layer structure. When a ∼30 nm thick silicone resin layer was coated on the ∼30 nm thick Fe3O4 layer, the eddy current loss was abruptly reduced from 364.2 W/kg to 8.6 W/kg (@ 1 T, 400 Hz). It was found that the silicone resin layer with high electrical resistivity contributed significantly in reducing eddy current loss, and a resin layer several of tens nanometers thick was sufficient to insulate Fe powder from each other.

Heteroepitaxy Growth and Characterization of High-Quality AlN Films for Far-Ultraviolet Photodetection.

The ultra-wide bandgap (~6.2 eV), thermal stability and radiation tolerance of AlN make it an ideal choice for preparation of high-performance far-ultraviolet photodetectors (FUV PDs). However, the challenge of epitaxial crack-free AlN single-crystalline films (SCFs) on GaN templates with low defect density has limited its practical applications in vertical devices. Here, a novel preparation strategy of high-quality AlN films was proposed via the metal organic chemical vapor deposition (MOCVD) technique. Cross-sectional transmission electron microscopy (TEM) studies clearly indicate that sharp, crack-free AlN films in single-crystal configurations were achieved. We also constructed a p-graphene/i-AlN/n-GaN photovoltaic FUV PD with excellent spectral selectivity for the FUV/UV-C rejection ratio of >103, a sharp cutoff edge at 206 nm and a high responsivity of 25 mA/W. This work provides an important reference for device design of AlN materials for high-performance FUV PDs.

Thickness Dependency of Battery Anode Properties in Multilayer Graphene.

With the development of practical thin-film batteries, multilayer graphene (MLG) is being actively investigated as an anode material. Therefore, research on determining a technique to fabricate thick MLG on arbitrary substrates at low temperatures is essential. In this study, we formed an MLG with controlled thickness at low temperatures using a layer exchange (LE) technique and evaluated its anode properties. The LE technique enabled the formation of a uniform MLG with a wide range of thicknesses (25-500 nm) on Ta foil. The charge/discharge characterization using coin-type cells revealed that the total capacity, which corresponded to Li intercalation into the MLG interlayer, increased with increasing MLG thickness. In contrast, cross-sectional transmission electron microscopy showed a metal oxide formed at the MLG/Ta interface during annealing, which had small Li capacity. MLG with sufficient thickness (500 nm) exhibited an excellent Coulombic efficiency and capacity retention compared to bulk graphite formed at high temperatures. These results have led to the development of inexpensive and reliable rechargeable thin-film batteries.

A hybrid chemical modification strategy for monocrystalline silicon micro-grinding: Experimental investigation and synergistic mechanism

For high performance manufacturing of micro parts and features, a hybrid chemical modification strategy is proposed to decrease critical energy barrier of mechanical removal of hard and brittle crystal material by refining localized machining condition. The strategy, namely UV-light and IR-laser hybrid chemical modification (UVIR-CM) strategy, includes two steps, an ultraviolet light (UV-light) catalytic advanced oxidation and an infrared laser (IR-laser) assisted selective modification based on Fenton liquid–solid reaction for monocrystalline silicon. The modification effects of UVIR-CM strategy were investigated by surface morphology micro-observation, cross-section transmission electron microscopy (TEM) observation, Raman spectroscopy analysis and nanoindentation test. Experimental results demonstrated that varied degrees of laser texturing appeared on different strategy samples’ IR-laser scanned area. And the IR-laser thermal damage has been successfully inhibited due to the refraction and reflection of energy by bubbles in liquid medium. But for the UVIR-CM strategy, a uniform and amorphous silicate layer is detected in a certain boundary. The UV-light promotes oxidation cycle ability of the chemical solution and ensures sufficient oxide modified layer for subsequent step. Attributing to synergism of photochemical, photothermal and kinetic effects induced by IR-laser, the modified layer displays layered structure with about 600 nm thickness, (2.7 ± 0.60) GPa nanohardness, and (93.7 ± 22.9) GPa indentation modulus. And the layered structure is amorphous layer, nanocrystal and micro-twins layer from the surface to the interior of sample. Consequently, it reveals that the subsequent mechanical removal will become easy due to decreasing energy barrier of monocrystalline silicon in selective area. Meanwhile, its original excellent mechanical properties also are maintained under a certain depth. The results contribute to develop a novel combined micro-machining technology to achieve collaborative manufacturing of structure shape and surface integrity for micro parts and feature.

Fabrication and characterization of NbN/(TaN/NbN) N stacked Josephson junctions

In this work, we present a detailed study of the electrical properties of stacked NbN/(TaN/NbN) N Josephson junctions. Cross-sectional scanning transmission electron microscopy analysis of the 5-stacked junction shows that the multilayer interface is very flat, each barrier has the same thickness, and the sidewalls of the junctions are nearly perpendicular to the substrate. Stacked junctions of different sizes and stacking numbers all have only one transition in their current–voltage curves. This indicates that the critical currents of the junctions in the stacked junctions are almost the same, showing the stability and repeatability of the multilayer fabrication and etching process. At 4.2 K, the 4-stacked junction shows excellent Josephson properties with characteristic voltage V c of 3.54 mV, which is about four times the 0.88 mV of the single junction. The temperature dependence of critical current density J c and V c of the stacked junction with N = 1, 2, 4 were measured, all of which can be fitted with dirty-limit theory. Stacked junctions with larger V c or more stacked layers can be achieved by optimizing electrode and barrier thickness, barrier resistivity, and thermal relaxation rate, etc.

Growth and characterization of GePb/Ge multiple quantum wells

GePb/Ge multiple quantum well (MQW) structures with a Pb content of up to 7.2% were successfully grown on Ge(100) substrates via sputtering epitaxy. Scanning electron microscopy revealed that both the Pb content in the GePb layer and Ge layer thickness affect the Pb surface segregation. High-resolution X-ray diffraction and cross-sectional transmission electron microscopy indicated that the GePb/Ge MQW structures had a high crystal quality. Moreover, the thermal stability of the GePb/Ge MQW structures was investigated, and the MQW structures were found to be stable at an annealing temperature of 500 °C. The band gaps of the GePb/Ge MQWs were measured, and the band gap regulation caused by the quantum confinement effect was verified. These results indicate that the MQW structure is a promising approach for realizing efficient GePb light sources.

Structural, Optical, and Sensing Properties of Nb-Doped ITO Thin Films Deposited by the Sol-Gel Method.

The aim of the present study was the development of Nb-doped ITO thin films for carbon monoxide (CO) sensing applications. The detection of CO is imperious because of its high toxicity, with long-term exposure having a negative impact on human health. Using a feasible sol-gel method, the doped ITO thin films were prepared at room temperature and deposited onto various substrates (Si, SiO2/glass, and glass). The structural, morphological, and optical characterization was performed by the following techniques: X-ray diffractometry (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV/Vis/NIR spectroscopic ellipsometry (SE). The analysis revealed a crystalline structure and a low surface roughness of the doped ITO-based thin films. XTEM analysis (cross-sectional transmission electron microscopy) showed that the film has crystallites of the order of 5-10 nm and relatively large pores (around 3-5 nm in diameter). A transmittance value of 80% in the visible region and an optical band-gap energy of around 3.7 eV were found for dip-coated ITO/Nb films on SiO2/glass and glass supports. The EDX measurements proved the presence of Nb in the ITO film in a molar ratio of 3.7%, close to the intended one (4%). Gas testing measurements were carried out on the ITO undoped and doped thin films deposited on glass substrate. The presence of Nb in the ITO matrix increases the electrical signal and the sensitivity to CO detection, leading to the highest response for 2000 ppm CO concentration at working temperature of 300 °C.

Morphology and chemical state of platinum ions implanted into glassy carbon substrates

Glassy carbon substrates were implanted with 100 keV platinum ions. The implanted samples were analyzed using cross-sectional transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy. Ion beam sputtering significantly affected the depth profile during platinum-ion implantation. Cross-sectional TEM revealed that the implanted platinum atoms were in the amorphous state and did not aggregate. Chemical state analysis of the platinum-ion-implanted glassy carbon substrates suggested that lattice defects in the substrates owing to the platinum-ion implantation caused the platinum–carbon interaction with electron transfer from platinum to carbon.

Kinetic influences on void formation in epitaxially regrown GaAs-Based PCSELs

We report an investigation into the formation of crystallographic voids during the metalorganic vapour phase epitaxial regrowth of GaAs photonic crystal structures. We employ a combination of cross-sectional scanning electron microscopy and scanning transmission electron microscopy to study structures regrown with AlAs, AlGaAs and GaAs. The change in regrowth material allows the effect of adatom diffusion kinetics on the void structure to be assessed. Whilst complete grating infill is observed for GaAs, void formation is promoted for Al-containing materials, with void size increasing with Al mole fraction, in line with reduced adatom mobility. In the case of both AlAs and AlGaAs-regrown structures, a degree of asymmetry is observed in the shape of the voids within the plane of the photonic crystal. These differences are attributed to variations in group-III adatom surface mobility and the polarities of high-index crystal planes along orthogonal crystal directions. Two growth regimes of stable and dynamic faceting are observed in cross-sections containing crystal planes with A- and B-type polarities, respectively.

Low-temperature copper–copper quasi-direct bonding with cobalt passivation layer

In this work, an ultra-thin cobalt film is used as a passivation layer to achieve a Cu–Cu quasi-direct bonding process, and successful bonding was achieved at the bonding temperature of 230 °C with the bonding pressure of 0.5 MPa in non-vacuum conditions. A tensile bonding strength of over 12.8 MPa can be achieved. With the cobalt layer, the total film roughness is greatly reduced to around 1 nm, and the cross-sectional transmission electron microscope images reveal the presence of a void-free bonding interface. Time-of-flight secondary ion mass spectrometry depth analysis is carried out using a PVD deposited multilayer sample, which simulates the bonding process without pressure. It is found that a Cu–Co intermixing layer formed between the Cu and Co interfaces during annealing, and Cu has diffused into the Co layer. Due to the nanocrystalline structure of the Co film and the low roughness of the system, a low bonding temperature can be achieved. These results demonstrate that Co, which can be selectively grown on the Cu surface, can be used as a passivation layer to achieve low-cost and high-quality interconnect for the three-dimensional integrated circuits.

Structural Defects and Ferromagnetic Signature of V-Doped Sb2Te3 Thin Films Grown on SrTiO3(001) Produced by RF-Magnetron Sputtering.

Thin films of V-doped Sb2Te3 compounds were fabricated by co-deposition of Sb2Te3 and V using rf-magnetron sputtering onto SrTiO3(001) substrates kept at 570 K. The microstructures of the films were characterized using transmission electron microscopy (TEM) and electron diffraction. The crystal structure of the sputtered film (Sb38V2Te60) is the Bi2Te3-type structure with lattice parameters of a = 0.44 ± 0.03 nm and c = 3.02 ± 0.02 nm. A combination of cross-sectional and plan-view TEM observations revealed the preferential orientation of the c axis in the film's normal direction. A thin amorphous layer exists between the Sb2Te3 thin film and the SrTiO3 substrate. The interfacial amorphous layer relaxes the strain between the thin film and the substrate, and hence, it should promote the growth of a low-index atomic plane with a low surface free energy (i.e., (0001) of the Sb2Te3). The onset of ferromagnetic order was detected at temperatures below 70 K. A remarkable increase in magnetization was detected in the film's normal direction, which corresponds to the magnetic easy axis (i.e., c axis of the Sb2Te3). V3+ ions substituting Sb sites should contribute to ferromagnetism at low temperatures.

Failure analysis on silicon semiconductor device materials: optical and high-resolution microscopic assessments

Defects of silicon (Si) semiconductor epilayers are crucial to be identified at laboratory environs. The identification of failure and its rectification at laboratory settings is essential for large-scaling manufacturing of narrowed down semiconductor devices. This research documented the inspection, identification and the solution for defects found in the Si semiconductor epilayers, fabricated by a simple and conventional photolithography technique, with the integration of metal oxide nanomaterial, zinc oxide (ZnO). The semiconductor epilayers, Si wafer, Si oxide and ZnO coated SiO2 layer were formed and examined. Optical microscope images [high power microscope (HPM) and 3D profilometer] reveal smooth surface of semiconductor epilayers development through thermal oxidation and photolithography techniques. High power ultraviolet-visible (UV-Vis) justified the accuracy of wet thermal oxidation by examining the thickness of oxide layer on Si wafer at 3837.3 Å. The X-ray diffraction (XRD) analysis of sol-gel synthesized ZnO affirmed the hexagonal crystalline state and its nanoscale size at 54 nm. Field emission scanning electron microscopy (FESEM) has shown the insight of Si epilayer morphology with its elemental composition, which provides details of foreign substances on semiconductor surface. ZnO deposited Si epilayer was prepared through lamella preparation, prior to the cross-sectional field emission transmission electron microscopy (FETEM) analysis of the semiconductor, which revealed the uniformity of fabrication and ZnO distribution at Si epilayer. Failure analysis reported several defects on the Si epilayers in the state of patches and accumulation of impurities. The potential cause of the defects and the respective solutions are discussed as the accuracy and handling must be ensured throughout the fabrication process, to develop a flawless semiconductor for high performance applications.

Chitosan coating fabricated through nanotopography and alkylation for the prevention of bacterial attachment and corrosion

Although metallic materials are widely used in biomedical devices, most of them have no antibacterial property and exhibit corrosion-related problems in physiological environments. This study aimed to develop a biocide-free chitosan coating to inhibit bacterial adhesion and corrosion. First, a chitosan coating fabricated through nanotopography was formed on the surface of carbon steel by using soft imprinting technology. Next, hexanal was grafted onto the chitosan by using a Schiff base reaction. Nanomorphological assessments using scanning electron microscopy, confocal laser scanning microscopy, and cross-sectional transmission electron microscopy confirmed a concave width, depth, and bottom thickness of approximately 666, 242, and 208 nm, respectively. Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopy confirmed that hexanal was successfully grafted to chitosan. Finally, the surface hydrophobic properties, antibacterial adhesion, and electrochemical corrosion resistance of chitosan coatings with and without nanopatterning and hexanal grafting were investigated. The results indicated that the hydrophobic angle of chitosan with both nanopatterning and hexanal grafting exceeded 120° and that the hysteresis angle was only 20°, which may help inhibit the attachment of Staphylococcus aureus and Escherichia coli. During an electrochemical corrosion test, chitosan with both nanopatterning and hexanal grafting exhibited the highest corrosion potential and the lowest corrosion current density, indicating improved corrosion resistance. These results suggest that imparting nanopatterning and alkylation properties to chitosan solves not only the problem of bacterial attachment to bare metal substrates but also the problem of corrosion.

Reactive laser annealing of indium tin oxide: implications to crystal structure, defect composition, and plasma energy

The mechanisms governing the modification of the optoelectronic properties of low carrier concentration indium tin oxide (ITO) during reactive laser annealing (ReLaA) are investigated. ReLA combines the advantages of reactive ambient thermal annealing and laser annealing; utilizing laser processing of room-temperature sputtered ITO thin films in pressurized reactive environments to probe the films’ crystal structure and defect composition. Advanced ellipsometric modelling (considering depth-inhomogeneity and intra- and inter-grain carrier transport), cross-sectional transmission electron microscopy, and X-ray photoelectron spectroscopy revealed ReLA-induced depth-dependent compositional and structural modifications that tuned the carrier concentration ((0.3 − 1.27) × 1020 cm−3) and epsilon-near-zero domain ( 3.07 − 11.7 μ m ) across a wider range than previously reported.

Beol-Compatible Ingazno-Based Devices for 3D Integrated Circuits

Due to its attractive materials and electrical properties, indium-gallium-zinc-oxide (IGZO) has been extensively researched in many emerging technologies, especially for three-dimensional (3D) monolithic integration and back-end-of-line (BEOL) compatible applications [1]. On the pathway toward the realization of high-performance 3D monolithic integrated chips (ICs), a wide range of building blocks with different functionalities are required. 3D monolithic ICs also demand optimization in device performance and circuit architecture design.In this paper, we discuss our recent research development in IGZO-based techniques at both device and circuit levels. This includes nanowire structure for IGZO-based transistors, as well as the BEOL-compatible ferroelectric ternary content-addressable memory (TCAM) and embedded dynamic random-access-memory (eDRAM) for compute-in-memory (CiM) using IGZO-based transistors.A novel digital etch technique for amorphous IGZO (α-IGZO) material as well as the formation of α-IGZO nanowires were realized, enabling high performance α-IGZO nanowire field-effect transistors (NWFETs) with ultra-scaled nanowire width (W NW) [2]. The scanning electron microscopy (SEM) images of α-IGZO nanowire before and after the digital etch show that the nanowire structure as well as W NW reduction after digital etch can be clearly observed. The smallest α-IGZO nanowire after digital etch has a W NW of ~20 nm. By leveraging the ultra-scaled nanowire structure, the NWFET with the smallest W NW achieves decent subthreshold swing of 80 mV/decade as well as high peak extrinsic transconductance (G m,ext) of 612 μS/μm at a drain to source voltage (V DS) = 2 V (456 μS/μm at V DS = 1 V). As compared with previous works in literature, our IGZO NWFET achieves one of the highest peak G m among all IGZO-based FETs. α-IGZO ferroelectric FETs (Fe-FETs) with a metal-ferroelectric-metal-oxide-semiconductor (MFMIS) structure were further realized based on the α-IGZO transistor process modules. The smallest L CH is as small as 40 nm. The cross-sectional transmission electron microscopy (TEM) image of the device shows sharp interface. The α-IGZO Fe-FETs achieve a large memory window of 2.9 V, high endurance of 108 cycles, high conductance ratio, and small cycle-to-cycle variation. By leveraging the low temperature processed α-IGZO Fe-FETs with good electrical characteristics, a BEOL-compatible ferroelectric TCAM circuit with 2 Fe-FETs connected in parallel was realized [3], showing an extremely large sensing margin. In addition, such α-IGZO Fe-FET TCAM reduces the transistor number from 16 to 2 as compared to traditional SRAM-based TCAM. Smaller cell size and higher energy efficiency can also be obtained.IGZO transistors can play an important role in in-memory computing as well. SEM image of the eDRAM CiM cell shows utilization of IGZO transistors. The smallest device has L CH of 45 nm [4]. The IGZO transistor-based eDRAM CiM with differential cell structure achieves low leakage current, low variation, low charge loss sensitivity, and the control-friendly charge-domain computing without DC power. By evaluating the key figure-of-merits, including precision, power efficiency, computing density, retention time, and robustness, it can be concluded that our IGZO transistor-based eDRAM CiM is promising for low-power and scalable compute-in-eDRAM design. Acknowledgments: This work is supported by Singapore Ministry of Education (Tier 2: MOE2018-T2-2-154, Tier 1: R-263-000-D65-114).