Channel Resistance Research Articles

Resistive Switching in α-In2Se3 Lateral Field-Effect Transistors.

Ferroelectric semiconducting field-effect transistors (FeS-FETs) based on two-dimensional materials exhibit nonvolatile resistive switching, making them promising candidates for next-generation memory and neuromorphic computing. However, the mechanisms governing resistive switching in α-In2Se3 lateral devices remain unresolved, particularly regarding the relative contributions of channel and contact resistance. In this study, Kelvin probe force microscopy (KPFM) was employed to spatially resolve the gate-poling-dependent contact and channel resistances in α-In2Se3 FeS-FETs, while scanning photocurrent microscopy (SPCM) was used to quantify changes in effective Schottky barrier height at the metal contacts. Both contact and channel resistances were found to increase (decrease) with positive (negative) poling, with the contact resistance modulation correlating with changes in Schottky barrier height. Control experiments on as-exfoliated multidomain flakes confirmed that spontaneous polarization influences both channel and contact resistances. However, typical clockwise resistive switching characteristics can be observed even in the absence of detectable ferroelectric polarization switching. Furthermore, typical gate-poling conditions lead to the formation of stacking defects observed by ex situ high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The observed defects can impede domain wall motion, providing a rationale for the lack of an abrupt switching threshold and a possible mechanism of coupling in-plane fields to out-of-plane polarization. We conclude that resistive switching in α-In2Se3 lateral channel devices is often influenced by both reversible polarization switching and irreversible defect formation, highlighting the need for improved domain wall control and defect mitigation strategies to enhance FeS-FET performance for reliable memory applications.

Impact of mixed-height vegetation patches on energy loss in open-channel flow

This study investigates the influence of riparian vegetation on energy losses in open-channel flow, focusing on channels partially covered by mixed-height vegetation patches, a common feature in natural rivers and canals. While previous research has primarily focused on flow resistance in fully vegetated channels, there has been limited attention to channels with unevenly distributed vegetation patches. To address this gap, we developed an innovative experimental approach to evaluate energy loss in channels with mixed-height vegetation patches under different submergence conditions. The experimental setup involved a channel partially covered with vegetation of varying heights, mimicking the natural, uneven distribution of vegetation patches. The results provided key insights into flow velocity distribution and turbulence intensity under these conditions. Furthermore, we introduced a standardized conceptualization method for the submergence ratio, specifically the concept of effective height (), to standardize the calculation methods for submerged and emergent vegetation.Using this parameter, we derived a theoretical formula for calculating energy loss caused by vegetation patches, which closely matched the experimental data. This method offers a reliable framework for calculating hydraulic resistance in channels with uneven vegetation distribution.

The effect of sloping floodplain on flow resistance and discharge in straight compound channels with single floodplain

The effect of sloping floodplain on flow resistance and discharge in straight compound channels with single floodplain

Trade-offs encountered in traditional mobility enhancement techniques applied to contact-controlled thin film transistors

Various mobility enhancement strategies are used at the material, process, and design geometry levels, to improve the performance of conventional thin film transistors (TFTs). These include the optimization of contact barrier height, semiconductor carrier concentration, post-annealing, and channel length optimization. In this study, the effects of these strategies on the performance metrics of contact-controlled amorphous Indium Gallium Zinc oxide (a-IGZO) TFTs are analyzed. Using a low barrier contact metal and a higher channel concentration can enhance the mobility of these TFTs by aiding the high field mode of operation with barrier lowering effect, but this leads to higher values of saturation coefficient, channel length sensitivity, and saturation voltage, with a lower value of output impedance. For a device working in the low-field mode, though the process of annealing improves the mobility characteristics, it deteriorates contact-controlled performance. Channel length upscaling also negatively affects all the contact-controlled performance metrics except output impedance. Thus, this study brings out the deteriorative effect of conventional mobility enhancement strategies on the performance metrics of a contact-controlled device, by unraveling the underlying semiconductor transport physics and the interplay between contact resistance and channel resistance.

Extreme Enhancement‐Mode Operation Accumulation Channel Hydrogen‐Terminated Diamond FETs with Vth < −6 V and High on‐Current

AbstractIn this work, a new Field Effect Transistor device concept based on hydrogen‐terminated diamond (H‐diamond) is demonstrated that operates in an Accumulation Channel rather than a Transfer Doping regime. The FET devices demonstrate both extreme enhancement‐mode operation and high on‐current with improved channel charge mobility compared to Transfer‐Doped equivalents. Electron‐beam evaporated Al2O3 is used on H‐diamond to suppress the Transfer Doping mechanism and produce an extremely high ungated channel resistance. A high‐quality H‐diamond surface with an unpinned Fermi level is crucially achieved, allowing for the formation of a high‐density hole accumulation layer by gating the entire device channel which is encapsulated in dual‐stacks of Al2O3. Completed devices with gate/channel length of 1 µm demonstrate record threshold voltage < −6 V with on‐current > 80 mA mm−1. Carrier density and mobility figures extracted by CV analysis indicate a high 2D charge density of ≈ 2 × 1012 cm−2 and increased hole mobility of 110 cm2 V−1 s−1 in comparison with more traditional Transfer‐Doped H‐diamond FETs. These results demonstrate the most negative threshold voltage yet reported for H‐diamond FETs and highlight a powerful new strategy to greatly improve carrier mobility and enable enhanced high power and high frequency diamond transistor performance.

Sliding ferroelectricity-induced triple barrier modulation in van der Waals boron arsenide tunnel junctions

To develop low-power, miniature, nonvolatile memory resistor integrated devices for in-memory computing technologies, the exploration of atomic-scale ferroelectric channel semiconductor devices is necessary. We theoretically designed tunnel junction devices based on two-dimensional ferroelectric semiconductors, with two-dimensional metal TaSe2 used as the top electrode and van der Waals bilayer boron arsenide (BAs) as the ferroelectric semiconductor channel, aiming to achieve high-performance, low-power, two-dimensional ferroelectric memory resistors. Our findings demonstrate that the bilayer BAs, upon contact with metal electrodes, can achieve two stable and switchable ferroelectric states. Interlayer relative sliding enables stable and alternating two-dimensional ferroelectric domains, altering the types of triple potential barriers at interfaces from Schottky contacts to Ohmic contacts. Thus, under the modulation of the “triple barrier” mechanism, control over channel carrier switching is achieved, resulting in a tunneling electroresistance of 104%. Additionally, non-equilibrium Green's function results indicate nonlinear changes in the I–V curve when switching between the two stable ferroelectric states, highlighting the multi-resistive state nature of channel resistance. Our research underscores the potential of sliding ferroelectric tunnel junctions in integrating nonvolatile storage and computing units, emphasizing their innovative applications in in-memory computing technologies.

A correction method of split C–V characteristics based on transmission line model for accurate evaluation of surface carrier concentration and effective mobility in MOSFETs

Abstract A split C-V measurement is a technique commonly used for evaluating surface carrier density and inversion layer mobility in MOSFETs. On the other hand, the accuracy of surface carrier density evaluated by split C-V can be affected by channel resistance. In this study we propose a method to correct the impact of channel resistance on split C-V measurements by using both capacitance and conductance experimental data. We employ a transmission line model to express the relationship between ideal and measured Cgc values and obtain the correct Cgc values. The effectiveness of this correction method is experimentally verified by long-channel Si MOSFETs at room and cryogenic temperatures. It is demonstrated that accurate effective mobility evaluation is realized by using this method.

Intrinsic field-effect mobility in thin-film transistor with polycrystalline In2O3 channel based on transfer length method

Abstract Field-effect mobility (μ FE), calculated using transconductance in thin-film transistors (TFTs) includes error factors from determination of channel width/length and parasitic resistance (R s/d) at source and drain regions. The apparent μ FE is generally underestimated owing to the drain voltage drop due to R s/d, which in turn, is caused by a low channel resistance (R ch) in high-mobility channels. This letter describes the extraction of intrinsic μ FE (μ FEi) in TFTs with polycrystalline In2O3 channels by separating R s/d and R ch, based on the transfer length method. Using the proposed methodology, we obtained a high μ FEi (>100 cm2 Vs−1) from TFT.

Dynamic fluidic manipulation in microfluidic chips with dead-end channels through spinning: the Spinochip technology for hematocrit measurement, white blood cell counting and plasma separation.

Centrifugation is crucial for size and density-based sample separation, but low-volume or delicate samples suffer from loss and impurity issues during repeated spins. We introduce the "Spinochip", a novel microfluidic system utilizing centrifugal forces for efficient filling of dead-end microfluidic channels. The Spinochip enables versatile fluid manipulation with a single reservoir for both inlet and outlet functions. It expels compressed air, facilitating fluid flow, and offers programmable filling mechanisms based on the hydraulic resistance of microfluidic channels. Compatible with a basic centrifuge, it allows sequential filling, internal mixing, and collection in straight microfluidic channels by simply adjusting the spinning speed, eliminating the need for complex valving. We demonstrated the Spinochip's efficacy in blood testing, where it successfully separated blood components, such as plasma, buffy coat, and red blood cells, from a single drop using centrifugation alone. This system enabled simultaneous hematocrit (R2 >0.99) and total white blood cell (R2 >0.93) quantification within a single microfluidic channel without the need for staining or special reagents. Remarkably, the Spinochip can perform hematocrit measurements on as little as 100 nL of blood, potentially paving the way for less invasive blood analysis. This innovative approach unlocks new possibilities in microfluidics, providing precise fluidic control and centrifugation for sample volumes as small as a few nanoliters.

Optical interferometry of high-energy nanosecond pin-to-pin discharges in atmospheric air

Abstract This paper describes the construction and application of an optical-frequency Michelson interferometer for measuring electron number density within high-energy, high-power nanosecond pin-to-pin discharges (>10 mJ pulse energy, >1 MW pulse power). A 21 mJ, 11 ns spark across a 3 mm pin-to-pin electrode gap was analyzed at 7 ns into the discharge to demonstrate the operation of the interferometer. A peak electron density of 2.3×1017 cm-3 was observed at these conditions, and it was consistent with estimates of plasma channel resistance based on V-I measurements. This initial work paves the way for a larger parametric study of the spatial and temporal dynamics of electron number density in nanosecond pin-do-pin discharges under various conditions.

Low-Frequency Noise Related to the Scattering Effect in p-Type Copper(I) Oxide Thin-Film Transistors.

In this study, we investigate the origins of low-frequency noise (LFN) and 1/f noise in Cu2O thin-film transistors (TFTs). The static direct current (DC) I-V characterization demonstrates that the channel resistance (Rch) contributes significantly to mobility degradation in the TFTs, with channel thickness (tch) controlled through the plasma-enhanced atomic layer deposition (PEALD) process. The 1/f noise followed the Hooge mobility fluctuation (HMF) model, and it was observed that both Coulomb and phonon scattering within the channel, which increased with a decrease in tch, contributed simultaneously. Increased Rch contributed more significantly to the 1/f noise than to the contact resistance (RC), as evidenced by the RC configuration of the measurements, which also revealed that RC depends upon tch. This study demonstrates that tch is a major noise source in Cu2O TFTs and presents guidelines for the development of Cu2O TFTs and potential high-mobility p-type oxide semiconductors.

Alanine to glycine substitution in the PyR2 confers sodium channel resistance to Type I pyrethroids.

Aedes aegypti is a primary urban vector of dengue, yellow fever, Zika and chikungunya worldwide. Pyrethroid insecticides are the most effective insecticides for controlling Ae. aegypti. However, pyrethroid resistance has developed due to the long-term overuse of the insecticides, and many knockdown resistance (kdr) mutations have been identified in the resistant populations. A1007G, an alanine to glycine substitution, was found in resistant Ae. aegypti from Vietnam and Malaysia, which has always co-existed with F1534C and V1016G. However, the role of A1007G in pyrethroid resistance and the linkage of A1007G and F1534C or V1016G remain unknown. In this study, we examined the effects of mutations on the sodium channel gating properties and pyrethroid sensitivity in Xenopus oocytes. We found mutations A1007G, A1007G + F1534C and A1007G + V1016G + F1534C shifted the voltage dependence of activation in the depolarizing direction. Mutations A1007G + F1534C and A1007G + V1016G + F1534C shifted the voltage dependence of inactivation in the depolarizing direction. Both mutations A1007G and F1534C reduced the channel sensitivity to two Type I pyrethroids, permethrin and bifenthrin, and synergistic effects were observed between mutations A1007G and F1534C. However, none of the mutations, A1007G, F1534C and A1007G + F1534C affected the channel sensitivity to two Type II pyrethroids, deltamethrin and cypermethrin. Furthermore, triple mutations A1007G + V1016G + F1534C significantly reduced the channel sensitivity to both Type I and Type II pyrethroids. We identified A1007G had a distinct effect on sodium channel sensitivity to Type I, but not to Type II pyrethroids, also A1007G exhibited synergistic effects with F1534C to Type I pyrethroids, which will provide a fundamental insight into the distinct molecular interactions between insect sodium channel and Type I or Type II pyrethroids. © 2024 Society of Chemical Industry.

Understanding the electric field dependent channel migration for shorter channel length of multilayer rhenium disulfide (ReS2) FETs

Multilayer rhenium disulfide (ReS2) has attracted considerable attention due to the decoupled van der Waals interaction between its adjacent layers, leading to significantly higher interlayer resistance compared with other layered materials. While the carrier transport in multilayer materials can be well described by the interlayer resistance (RInt) and Thomas-Fermi charge screening length (λTF) in resistor network models, the electric field scaling of the channel with the back gate voltage (VBG) and the drain voltage (VD) is limited in two-dimensional (2D) multilayer materials. In this report, we present the effects ofVBGandVDon the channel migration of ReS2field effect transistors (FETs) with channel lengths of 0.25, 2.4, and 4.4μm. For shorter channels, theVBG-dependent conductance (G= (drain current (ID)/VD)) increases with increasingVD, different from the longer channels. Based on the resistor network model, the different behaviors with channel lengths were analyzed by considering the interlayer resistance (RInt) versus the channel resistance and the Thomas-Fermi charge screening length (λTF). Lower back gate voltage (VBG) in shorter channels builds the channel near the bottom layer close to the oxide, while highVBGshifts the conductive channel to the top sheet exposed to ambient condition. In longer channels, due to the increased channel resistance (Rch), the conductive channel forms near the bottom side close to the oxide. The increase of the threshold voltage (Vth) was observed at higher drain-source voltages (VD), but in opposite for the top side channel, i.e. the decrease of threshold voltage with increasingVD. This study will give a hint on establishing the electric field scaling of 2D material-based FETs with channel lengths and applied voltages ofVBGandVD.

The Trapping Mechanism at the AlGaN/GaN Interface and the Turn-On Characteristics of the p-GaN Direct-Coupled FET Logic Inverters.

The trapping mechanism at the AlGaN/GaN interface in the p-GaN high electron mobility transistors (HEMTs) and its impact on the turn-on characteristics of direct-coupled FET logic (DCFL) inverters were investigated across various supply voltages (VDD) and test frequencies (fm). The frequency-conductance method identified two trap states at the AlGaN/GaN interface (trap activation energy Ec-ET ranges from 0.345 eV to 0.363 eV and 0.438 eV to 0.47 eV). As VDD increased from 1.5 V to 5 V, the interface traps captured more electrons, increasing the channel resistance (Rchannel) and drift-region resistance (Rdrift) of the p-GaN HEMTs and raising the low-level voltage (VOL) from 0.56 V to 1.01 V. At fm = 1 kHz, sufficient trapping and de-trapping led to a delay of 220 µs and a VOL instability of 320 mV. Additionally, as fm increased from 1 kHz to 200 kHz, a positive shift in the threshold voltage of p-GaN HEMTs occurred due to the dominance of trapping. This shift caused VOL to rise from 1.02 V to 1.40 V and extended the fall time (tfall) from 153 ns to 1 µs. This investigation enhances the understanding of DCFL GaN inverters' behaviors from the perspective of device physics on power switching applications.

Extension Doping with Low‐Resistance Contacts for P‐Type Monolayer WSe2 Field‐Effect Transistors

AbstractSource/Drain extension doping is crucial for minimizing the series resistance of the ungated channel and reducing the contact resistance of field‐effect transistors (FETs) in complementary metal–oxide–semiconductor (CMOS) technology. 2D semiconductors, such as MoS2 and WSe2, are promising channel materials for beyond‐silicon CMOS. A key challenge is to achieve extension doping for 2D monolayer FETs without damaging the atomically thin material. This work demonstrates extension doping with low‐resistance contacts for monolayer WSe2 p‐FETs. Self‐limiting oxidation transforms a bilayer WSe2 into a hetero‐bilayer of a high‐work‐function WOxSey on a monolayer WSe2. Then, damage‐free nanolithography defines an undoped nano‐channel, preserving the high on‐current of WOxSey‐doped FETs while significantly improving their on/off ratio. The insertion of an amorphous WOxSey interlayer under the contacts achieves record‐low contact resistances for monolayer WSe2 over a hole density range of 1012 to 1013 cm−2 (1.2 ± 0.3 kΩ µm at 1013 cm−2). The WOxSey‐doped extension exhibits a sheet resistance as low as 10 ± 1 kΩ □−1. Monolayer WSe2 p‐FETs with sub‐50 nm channel lengths reach a maximum drain current of 154 µA µm−1 with an on/off ratio of 107–108. These results define strategies for nanometer‐scale selective‐area doping in 2D FETs and other 2D architectures.

Simultaneous determination of refined values of mobility, channel and contact resistance in organic field-effect transistors utilizing the four- and three-probe methods

Abstract Accurate determination of charge carrier mobility is a critical aspect in an organic field-effect transistor (OFET) as it is tightly correlated to the development of new materials, better device designs and improved fabrication methods. The presence of high contact resistance at the metal–organic semiconductor interface introduces an intrinsic error in the extraction of charge carrier mobility. In this report, electrical circuit analysis for the determination of the refined channel mobility, total contact resistance and channel resistance values is showcased for a poly(3-hexylthiophene) OFET with bottom-gate bottom-contact architecture. The process of determination is based on the combination of the conventional four-probe and three-probe measurement techniques. These two techniques are used in conjunction to assess refined mobility values in the channel region. This is followed by the determination of total contact resistance and channel resistances. The results show that, at a fixed drain current, mobility increases with the gate voltage while both the contact and channel resistances decrease.

Summary of the results of field and laboratory studies of hydraulic resistance during channel bending

The reliability of channel forecasts, performed using mathematical modeling methods in the design of engineering activities on shipping rivers, largely depends on the accuracy of the assessment of hydraulic resistance and sediment transport parameters. Therefore, the hydraulic resistance of natural channels is one of the largest problems in the dynamics of channel flows and is the object of close attention of scientists. In the resistance of natural channels, roughness appears in three forms: the first of them is the roughness of the granular surface of the bottom; the second is the roughness created by boulders and the third type is the roughness of microforms: ripples and ridges. Channel mesoforms also contribute to the resistance to water movement: spits, side streams, middle streams, islands, bends of the channel and such complex formations as riffles. This type of resistance is usually called the resistance of the channel form. The resistance of the natural channel shape due to the movement and deformation of mesoforms can change significantly over time. The complexity and insufficient study of this issue significantly limit the possibilities of a theoretical approach to its solution. Therefore, the obtained results are mainly empirical or semiempirical in nature. The paper presents the results of experimental and field studies that allowed us to identify the main features of flow movement in winding sections of rivers. One of the features of flow movement at channel turns is the possibility of additional energy losses. The total resistance of a curved section of a channel is made up of three main parts: the resistance of the granular surface of the bottom, the resistance of the bottom ridges, and the resistance of the channel shape. The additional resistance created by the bend depends on the curvature of the channel, the rate of change in depth along the length of the bend, and also reflects the impact of side streams formed near the convex bank on the flow.

A Study on the Manufacture of CNT Composites Bipolar Plate for the Fuel Cell Using a Nanosecond Pulsed Laser

A Study on the Manufacture of CNT Composites Bipolar Plate for the Fuel Cell Using a Nanosecond Pulsed Laser

Study of AC Conductivity and Relaxation Times Depending on Moisture Content in Nanocomposites of Insulation Pressboard-Innovative Bio-Oil-Water Nanodroplets.

The aim of this study was to determine the frequency-temperature dependence of the AC conductivity and relaxation times in humid electrical pressboard used in the insulation of power transformers, impregnated with the innovative NYTRO® BIO 300X bio-oil produced from plant raw materials. Tests were carried out for a composite of cellulose-bio-oil-water nanodroplets with a moisture content of 0.6% by weight to 5% by weight in the frequency range from 10-4 Hz to 5·103 Hz. The measurement temperatures ranged from 20 °C to 70 °C. The current conductivity in percolation channels in cellulose-bio insulating oil-water nanodroplets nanocomposites was analyzed. In such nanocomposites, DC conduction takes place via electron tunneling between the potential wells formed by the water nanodroplets. It was found that the value of the percolation channel resistance is lowest in the case of a regular arrangement of the nanodroplets. As disorder increases, characterized by an increase in the standard deviation value, the percolation channel resistance increases. It was found that the experimental values of the activation energy of the conductivity and the relaxation time of the composite of cellulose-bio-oil-water nanodroplets are the same within the limits of uncertainty and do not depend on the moisture content. The value of the generalized activation energy is ΔE ≈ (1.026 ± 0.0160) eV and is constant over the frequency and temperature ranges investigated. This study shows that in the lowest frequency region, the conductivity value does not depend on frequency. As the frequency increases further, the relaxation time decreases; so, the effect of moisture on the conductivity value decreases. The dependence of the DC conductivity on the moisture content was determined. For low moisture contents, the DC conductivity is practically constant. With a further increase in water content, there is a sharp increase in DC conductivity. Such curves are characteristic of the dependence of the DC conductivity of composites and nanocomposites on the content of the conducting phase. A percolation threshold value of xc ≈ (1.4 ± 0.3)% by weight was determined from the intersection of flat and steeply sloping sections. The frequency dependence of the values of the relative relaxation times was determined for composites with moisture contents from 0.6% by weight to 5% by weight for a measurement temperature of 60 °C. The highest relative values of the relaxation time τref occur for direct current and for the lowest frequencies close to 10-4 Hz. As the frequency increases further, the relaxation time decreases. The derivatives d(logτref)/d(logf) were calculated, from the analysis of which it was determined that there are three stages of relaxation time decrease in the nanocomposites studied. The first occurs in the frequency region from 10-4 Hz to about 3·10-1 Hz, and the second from about 3·10-1 Hz to about 1.5·101 Hz. The beginning of the third stage is at a frequency of about 1.5·101 Hz. The end of this stage is above the upper range of the Frequency Domain Spectroscopy (FDS) meter, which is 5·103 Hz. It has been established that the nanodroplets are in the cellulose and not in the bio-oil. The occurrence of three stages on the frequency dependence of the relaxation time can be explained when the fibrous structure of the cellulose is taken into account. Nanodroplets, found in micelles, microfibrils and in the fibers of which cellulose is composed, can have varying distances between nanodroplets, determined by the dimensions of these cellulose components.

(Invited) Common Practical Challenges in Characterization of Wide-Bandgap Semiconductors

For the past decade, Sandia National Laboratories has been at the forefront of research in vertical gallium nitride power semiconductor devices. Prime examples of this are the demonstration of a world record > 6 kV GaN pn diode, as well as the first demonstration of a > 1.2 kV vertical GaN trench MOSFET with a HfO2 gate dielectric. In the past six years, Sandia has worked on a program funded by the Department of Energy’s Vehicle Technologies Office to develop vertical GaN power semiconductors for next-generation vehicle electrification. This talk focuses on the challenges and cycles of learning from that program as they relate to the characterization and development of wide bandgap (WBG) power semiconductors.Many of the conventional characterization techniques used for WBG semiconductors were developed for Si-based electronics in the latter half of the 20th century and were later adapted to WBG semiconductors. As the understanding of WBG semiconductors evolves over time, it becomes necessary to reevaluate these techniques for sources of error and to provide modifications and alternate methods which adapt to the nuances of the material being evaluated. One such example of this is the challenge in extracting the density of interface traps (DIT ) in a WBG metal oxide semiconductor (MOS) capacitor. We will explore some of the nuances in extracting DIT for a WBG semiconductor compared to silicon. In addition, we propose a method of visual qualification of the shape of the DIT vs. [EC-ET] curve which can be used to assess the accuracy of the extraction.Reducing channel resistance for MOSFETs is a key factor in improving performance and has an especially large impact for GaN or SiC vertical devices rated at 1700 V or below. A large contributing element to high channel resistance comes from low channel mobilities which are often reported as low as 15-30 cm2/V·s for SiC, but have been reported as high as 200 cm2/V·s for GaN. A common and basic technique for extracting mobility in SiC planar devices is to use fatFET structures which are long channel devices where the channel resistance becomes the dominant contributor to total device resistance, and hence provides an accurate method for extracting channel mobility. For trench MOSFETs, making a long channel device is not a viable option due to the channel orientation, hence it becomes challenging to find a good approach for extracting channel mobility. One method sometimes used to extract mobility is the transconductance method. We will discuss this method and the inaccuracy of this technique for extracting channel mobility in trench MOSFETs. In our study, the transconductance technique underestimates channel mobility by as much as 33% and the error is associated with the additional series resistance. We will discuss this issue and as well as alternate approaches to extracting mobility.Another challenge we report on concerns the extraction of contact resistivity and the limitations of various techniques. Using the circular transmission line model (CTLM) for extracting contact resistivity has several challenges related to the thickness of the semiconductor film below the contact, the correction factor approximation, and the error for extremely low resistivity contacts. For thick films, alternative methods like the Cox and Strack [1] method are significantly more area efficient. Understanding the limitations of these techniques helps set boundaries on our interpretation of data and is key in providing accurate information on contact resistivity. References R. H. Cox and H. Strack, Solid-State Electron. 10 (12), 1213 (1967). This work was supported by the Electric Drivetrain Consortium managed by Susan Rogers of DOE’s Vehicle Technologies Office. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government.