A low specific on-resistance SOI LDMOS with a novel junction field plate

A low specific on-resistance SOI LDMOS with a novel junction field plate(JFP) is proposed and investigated theoretically. The most significant feature of the JFP LDMOS is a PP–N junction field plate instead of a metal field plate. The unique structure not only yields charge compensation between the JFP and the drift region, but also modulates the surface electric field. In addition, a trench gate extends to the buried oxide layer(BOX) and thus widens the vertical conduction area. As a result, the breakdown voltage(BV) is improved and the specific on-resistance(Ron,sp) is decreased significantly.It is demonstrated that the BV of 306 V and the Ron,sp of 7.43 m?·cm2are obtained for the JFP LDMOS. Compared with those of the conventional LDMOS with the same dimensional parameters, the BV is improved by 34.8%, and the Ron,sp is decreased by 56.6% simultaneously. The proposed JFP LDMOS exhibits significant superiority in terms of the trade-off between BV and Ron,sp. The novel JFP technique offers an alternative technique to achieve high blocking voltage and large current capacity for power devices.

Ultra-low specific on-resistance vertical double-diffused metal-oxide semiconductor with a high-k dielectric-filled extended trench

An ultra-low specific on-resistance trench gate vertical double-diffused metal-oxide semiconductor with a high-k dielectric-filled extended trench(HK TG VDMOS) is proposed in this paper.The HK TG VDMOS features a high-k(HK) trench below the trench gate.Firstly,the extended HK trench not only causes an assistant depletion of the n-drift region,but also optimizes the electric field,which therefore reduces Ron,sp and increases the breakdown voltage(BV).Secondly,the extended HK trench weakens the sensitivity of BV to the n-drift doping concentration.Thirdly,compared with the superjunction(SJ) vertical double-diffused metal-oxide semiconductor(VDMOS),the new device is simplified in fabrication by etching and filling the extended trench.The HK TG VDMOS with BV = 172 V and Ron,sp = 0.85 mΩ·cm2 is obtained by simulation;its Ron,sp is reduced by 67% and 40% and its BV is increased by about 15% and 5%,in comparison with those of the conventional trench gate VDMOS(TG VDMOS) and conventional superjunction trench gate VDMOS(SJ TG CDMOS).

Dual-gate lateral double-diffused metal—oxide semiconductor with ultra-low specific on-resistance

A new high voltage trench lateral double-diffused metal-oxide semiconductor (LDMOS) with ultra-low specific onresistance (R on,sp ) is proposed. The structure features a dual gate (DG LDMOS): a planar gate and a trench gate inset in the oxide trench. Firstly, the dual gate can provide a dual conduction channel and reduce R on,sp dramatically. Secondly, the oxide trench in the drift region modulates the electric field distribution and reduces the cell pitch but still can maintain comparable breakdown voltage (BV). Simulation results show that the cell pitch of the DG LDMOS can be reduced by 50% in comparison with that of conventional LDMOS at the equivalent BV; furthermore, R on,sp of the DG LDMOS can be reduced by 67% due to the smaller cell pitch and the dual gate.

Ultra-low specific on-resistance high-voltage vertical double diffusion metal–oxide–semiconductor field-effect transistor with continuous electron accumulation layer

A new ultra-low specific on-resistance(Ron,sp) vertical double diffusion metal–oxide–semiconductor field-effect transistor(VDMOS) with continuous electron accumulation(CEA) layer, denoted as CEA-VDMOS, is proposed and its new current transport mechanism is investigated. It features a trench gate directly extended to the drain, which includes two PN junctions. In on-state, the electron accumulation layers are formed along the sides of the extended gate and introduce two continuous low-resistance current paths from the source to the drain in a cell pitch. This mechanism not only dramatically reduces the Ron,sp but also makes the Ron,sp almost independent of the n-pillar doping concentration(Nn). In off-state, the depletion between the n-pillar and p-pillar within the extended trench gate increases the Nn, and further reduces the Ron,sp.Especially, the two PN junctions within the trench gate support a high gate–drain voltage in the off-state and on-state, respectively. However, the extended gate increases the gate capacitance and thus weakens the dynamic performance to some extent. Therefore, the CEA-VDMOS is more suitable for low and medium frequencies application. Simulation indicates that the CEA-VDMOS reduces the Ron,sp by 80% compared with the conventional super-junction VDMOS(CSJ-VDMOS)at the same high breakdown voltage(BV).

Novel high- with low specific on-resistance high voltage lateral double-diffused MOSFET

A novel voltage-withstand substrate with high-K(HK, k > 3.9, k is the relative permittivity) dielectric and low specific on-resistance(Ron,sp) bulk-silicon, high-voltage LDMOS(HKLR LDMOS)is proposed in this paper. The high-K dielectric and highly doped interface N+-layer are made in bulk silicon to reduce the surface field drift region. The high-K dielectric can fully assist in depleting the drift region to increase the drift doping concentration(Nd) and reshape the electric field distribution. The highly doped N+-layer under the high-K dielectric acts as a low resistance path to reduce the Ron,sp. The new device with the high breakdown voltage(BV), the low Ron,sp, and the excellent figure of merit(FOM = BV^2/Ron,sp) is obtained. The BV of HKLR LDMOS is 534 V, Ron,sp is 70.6 m?·cm^2, and FOM is 4.039 MW·cm^(-2).

A low specific on-resistance SOI MOSFET with dual gates and a recessed drain

A low specific on-resistance(Ron,sp) integrable silicon-on-insulator(SOI) metal-oxide semiconductor field-effect transistor(MOSFET) is proposed and investigated by simulation.The MOSFET features a recessed drain as well as dual gates,which consist of a planar gate and a trench gate extended to the buried oxide layer(BOX)(DGRD MOSFET).First,the dual gates form dual conduction channels,and the extended trench gate also acts as a field plate to improve the electric field distribution.Second,the combination of the trench gate and the recessed drain widens the vertical conduction area and shortens the current path.Third,the P-type top layer not only enhances the drift doping concentration but also modulates the surface electric field distributions.All of these sharply reduce Ron,sp and maintain a high breakdown voltage(BV).The BV of 233 V and Ron,sp of 4.151 mΩ·cm2(VGS = 15 V) are obtained for the DGRD MOSFET with 15-μm half-cell pitch.Compared with the trench gate SOI MOSFET and the conventional MOSFET,Ron,sp of the DGRD MOSFET decreases by 36% and 33% with the same BV,respectively.The trench gate extended to the BOX synchronously acts as a dielectric isolation trench,simplifying the fabrication processes.

Closed-form breakdown voltage/specific on-resistance model using charge superposition technique for vertical power double-diffused metal–oxide–semiconductor device with high-κ insulator

An improved vertical power double-diffused metal–oxide–semiconductor(DMOS) device with a p-region(P1) and high-κ insulator vertical double-diffusion metal–oxide–semiconductor(HKP-VDMOS) is proposed to achieve a better performance on breakdown voltage(BV)/specific on-resistance(Ron,sp) than conventional VDMOS with a high-κ insulator(CHK-VDMOS).The main mechanism is that with the introduction of the P-region,an extra electric field peak is generated in the drift region of HKP-VDMOS to enhance the breakdown voltage.Due to the assisted depletion effect of this p-region,the specific on-resistance of the device could be reduced because of the high doping density of the N-type drift region.Meanwhile,based on the superposition of the depleted charges,a closed-form model for electric field/breakdown voltage is generally derived,which is in good agreement with the simulation result within 10% of error.An HKP-VDMOS device with a breakdown voltage of 600 V,a reduced specific on-resistance of 11.5 m?·cm^2 and a figure of merit(FOM)(BV^2/Ron,sp)of 31.2 MW·cm^(-2) shows a substantial improvement compared with the CHK-VDMOS device.

An ultra-low specific on-resistance trench LDMOS with a U-shaped gate and accumulation layer

An ultra-low specific on-resistance(Ron,sp) oxide trench-type silicon-on-insulator(SOI) lateral double-diffusion metal–oxide semiconductor(LDMOS) with an enhanced breakdown voltage(BV) is proposed and investigated by simulation. There are two key features in the proposed device: one is a U-shaped gate around the oxide trench, which extends from source to drain(UG LDMOS); the other is an N pillar and P pillar located in the trench sidewall. In the on-state, electrons accumulate along the U-shaped gate, providing a continuous low resistance current path from source to drain. The Ron,sp is thus greatly reduced and almost independent of the drift region doping concentration. In the off-state, the N and P pillars not only enhance the electric field(E-field) strength of the trench oxide, but also improve the E-field distribution in the drift region, leading to a significant improvement in the BV. The BV of 662 V and Ron,sp of 12.4 m?·cm2are achieved for the proposed UG LDMOS. The BV is increased by 88.6% and the Ron,sp is reduced by 96.4%, compared with those of the conventional trench LDMOS(CT LDMOS), realizing the state-of-the-art trade-off between BV and Ron,sp.

Low specific on-resistance GaN-based vertical heterostructure field effect transistors with nonuniform doping superjunctions

A novel Ga N-based vertical heterostructure field effect transistor(HFET) with nonuniform doping superjunctions(non-SJ HFET) is proposed and studied by Silvaco-ATLAS,for minimizing the specific on-resistance(R_(on)A) at no expense of breakdown voltage(BV).The feature of non-SJ HFET lies in the nonuniform doping concentration from top to bottom in the n-and p-pillars,which is different from that of the conventional Ga N-based vertical HFET with uniform doping superjunctions(un-SJ HFET).A physically intrinsic mechanism for the nonuniform doping superjunction(non-SJ) to further reduce R_(on)A at no expense of BV is investigated and revealed in detail.The design,related to the structure parameters of non-SJ,is optimized to minimize the R_(on)A on the basis of the same BV as that of un-SJ HFET.Optimized simulation results show that the reduction in R_(on)A depends on the doping concentrations and thickness values of the light and heavy doping parts in non-SJ.The maximum reduction of more than 51% in R_(on)A could be achieved with a BV of 1890 V.These results could demonstrate the superiority of non-SJ HFET in minimizing R_(on)A and provide a useful reference for further developing the Ga N-based vertical HFETs.

Design of Fully Automatic Specification Selection System for Resistance Welding Equipment

A system for fully automatic selection of welding specifications in resistance welding equipment has been developed to address the problem of workers frequently choosing the wrong specifications during manual welding of multiple parts on a single machine in automobile factories. The system incorporates an automatic recognition system for different workpiece materials using the added machine fixture,visual detection system for nuts and bolts,and secondary graphical confirmation to ensure the correctness of specification calling. This system achieves reliable,fully automatic selection of welding specifications in resistance welding equipment and has shown significant effects in improving welding quality for massproduced workpieces,while solving the problem of specification calling errors that can occur with traditional methods involving process charts and code adjustments. This system is particularly suitable for promoting applications in manual welding of multiple parts on a single machine in automobile factories,ensuring correct specification calling and welding quality.

Enhancing Relational Triple Extraction in Specific Domains:Semantic Enhancement and Synergy of Large Language Models and Small Pre-Trained Language Models

In the process of constructing domain-specific knowledge graphs,the task of relational triple extraction plays a critical role in transforming unstructured text into structured information.Existing relational triple extraction models facemultiple challenges when processing domain-specific data,including insufficient utilization of semantic interaction information between entities and relations,difficulties in handling challenging samples,and the scarcity of domain-specific datasets.To address these issues,our study introduces three innovative components:Relation semantic enhancement,data augmentation,and a voting strategy,all designed to significantly improve the model’s performance in tackling domain-specific relational triple extraction tasks.We first propose an innovative attention interaction module.This method significantly enhances the semantic interaction capabilities between entities and relations by integrating semantic information fromrelation labels.Second,we propose a voting strategy that effectively combines the strengths of large languagemodels(LLMs)and fine-tuned small pre-trained language models(SLMs)to reevaluate challenging samples,thereby improving the model’s adaptability in specific domains.Additionally,we explore the use of LLMs for data augmentation,aiming to generate domain-specific datasets to alleviate the scarcity of domain data.Experiments conducted on three domain-specific datasets demonstrate that our model outperforms existing comparative models in several aspects,with F1 scores exceeding the State of the Art models by 2%,1.6%,and 0.6%,respectively,validating the effectiveness and generalizability of our approach.

Ultra-low specific on-resistance SOI double-gate trench-type MOSFET

An ultra-low specific on-resistance(Ron,sp) silicon-on-insulator（SOI） double-gate trench-type MOSFET （DG trench MOSFET） is proposed.The MOSFET features double gates and an oxide trench:the oxide trench is in the drift region,one trench gate is inset in the oxide trench and one trench gate is extended into the buried oxide.Firstly,the double gates reduce Ron,sp by forming dual conduction channels.Secondly,the oxide trench not only folds the drift region,but also modulates the electric field,thereby reducing device pitch and increasing the breakdown voltage（BV）.A BV of 93 V and a Ron,sp of 51.8 mΩ·mm2 is obtained for a DG trench MOSFET with a 3μm half-cell pitch.Compared with a single-gate SOI MOSFET（SG MOSFET） and a single-gate SOI MOSFET with an oxide trench（SG trench MOSFET）,the Ron,sp of the DG trench MOSFET decreases by 63.3%and 33.8% at the same BV,respectively.

A 800 V dual conduction paths segmented anode LIGBT with low specific on-resistance and small shift voltage

A dual conduction paths segmented anode lateral insulated-gate bipolar transistor(DSA-LIGBT) which uses triple reduced surface field(RESURF) technology is proposed. Due to the hybrid structures of triple RESURF LDMOS(T-LDMOS) and traditional LIGBT, firstly, a wide p-type anode is beneficial to the small shift voltage.VST) and low specific on-resistance(Ron;sp) when the anode voltage(VA) is larger than VST. Secondly, a wide ntype anode and triple RESURF technology are used to get a low Ron;spwhen VAis less than VST. Meanwhile, it can accelerate the extraction of electrons, which brings a low turn-off time(Toff). Experimental results show that: VST is only 0.9 V, Ron;sp(Ron Area) are 11.7 and 3.6 mm2when anode voltage VAequals 0.9 and 3 V, respectively,the breakdown voltage reaches to 800 V and Toffis only 450 ns.

Ultralow specific on-resistance high voltage trench SOI LDMOS with enhanced RESURF effect

A RESURF-enhanced high voltage SOI LDMOS(ER-LDMOS) with an ultralow specific on-resistance(R_(on,sp)) is proposed.The device features an oxide trench in the drift region,a P-pillar at the sidewall of the trench,and a buried P-layer(BPL) under the trench.First,the P-pillar adjacent to the P-body not only acts as a vertical junction termination extension(JTE),but also forms a vertical reduced surface field(RESURF) structure with the Ndrift region.Both of them optimize the bulk electric field distributions and increase the doping concentration of the drift region.Second,the BPL together with the N-drift region and the buried oxide layer(BOX) exhibits a tripleRESURF effect,which further improves the bulk field distributions and the doping concentration.Additionally,multiple-directional depletion is induced owing to the P-pillar,the BPL,and two MIS-like structures consisting of the N-drift region combined with the oxide trench and the BOX.As a result,a significantly enhanced-RESURF effect is achieved,leading to a high breakdown voltage(BV) and a low R_(on,sp).Moreover,the oxide trench folds the drift region in the vertical direction,resulting in a reduced cell pitch and thus R_(on,sp) Simulated results show that the ER-LDMOS improves BV by 67% and reduces R_(on,sp) by 91% compared with the conventional trench LDMOS at the same cell pitch.

Ultralow specific ON-resistance high-k LDMOS with vertical field plate

An ultralow specific on-resistance high-k LDMOS with vertical field plate(VFP HK LDMOS) is proposed. The high-k dielectric trench and highly doped interface N+ layer are made in bulk silicon to reduce the surface field of the drift region in the VFP HK LDMOS. The gate vertical field plate(VFP) pinning in the high-k dielectric trench can modulate the bulk electric field. The high-k dielectric not only provides polarized charges to assist depletion of the drift region, so that the drift region and high-k trench maintain charge balance adaptively,but also can fully assist in depleting the drift region to increase the drift doping concentration and reshape the electric field to avoid premature breakdown. Compared with the conventional structure, the VFP HK LDMOS has the breakdown voltage of 629.1 V at the drift length of 40 μm and the specific on-resistance of 38.4 mΩ·cm^2 at the gate potential of 15 V. Then the power figure of merit is 10.31 MW/cm^2.

A novel multiple super junction power device structure with low specific on-resistance

A novel multiple super junction(MSJ) LDMOS power device is proposed to decrease Rondue to lateral and vertical interactions between the N-pillar and P-pillar. In the studied device: multiple layers of SJ are introduced oppositely under surface SJ; when compared with 2D-depleting of the conventional super junction(CSJ), a 3Ddepleted effect is formed in the MSJ thanks to vertical electric field modulation; and, current distribution is improved by deep drain, which increases the drift doping concentration and results in a lower on-resistance. The high electric field around the drain region by substrate-assisted depleted effect is reduced due to the charge balance result from the electric field shielding effect of the bottom SJ, which causes the uniform electric field in the drift region and the high breakdown voltage. The numerical simulation results indicate that the specific on-resistance of the MSJ device is reduced by 42% compared with that of CSJ device, while maintaining a high breakdown voltage; the cell pitch of the device is 12 m.

SbMYB3 transcription factor promotes root-specific f lavone biosynthesis in Scutellaria baicalensis

Scutellaria baicalensis Georgi produces abundant root-specific f lavones(RSFs),which provide various benefits to human health.We have elucidated the complete biosynthetic pathways of baicalein and wogonin.However,the transcriptional regulation of f lavone biosynthesis in S.baicalensis remains unclear.We show that the SbMYB3 transcription factor functions as a transcriptional activator involved in the biosynthesis of RSFs in S.baicalensis.Yeast one-hybrid and transcriptional activation assays showed that SbMYB3 binds to the promoter of flavone synthase II-2(SbFNSII-2)and enhances its transcription.In S.baicalensis hairy roots,RNAi of SbMYB3 reduced the accumulation of baicalin and wogonoside,and SbMYB3 knockout decreased the biosynthesis of baicalein,baicalin,wogonin,and wogonoside,whereas SbMYB3 overexpression enhanced the contents of baicalein,baicalin,wogonin,and wogonoside.Transcript profiling by qRT–PCR demonstrated that SbMYB3 activates SbFNSII-2 expression directly,thus leading to more abundant accumulation of RSFs.This study provides a potential target for metabolic engineering of RSFs.

Performances of a Stinger PDC cutter breaking granite: Cutting force and mechanical specific energy in single cutter tests

The Stinger PDC cutter has high rock-breaking efficiency and excellent impact and wear resistance, which can significantly increase the rate of penetration (ROP) and extend PDC bit life for drilling hard and abrasive formation. The knowledge of force response and mechanical specific energy (MSE) for the Stinger PDC cutter is of great importance for improving the cutter's performance and optimizing the hybrid PDC bit design. In this paper, 87 single cutter tests were conducted on the granite. A new method for precisely obtaining the rock broken volume was proposed. The influences of cutting depth, cutting angle, and cutting speed on cutting force and MSE were analyzed. Besides, a phenomenological cutting force model of the Stinger PDC cutter was established by regression of experimental data. Moreover, the surface topography and fracture morphology of the cutting groove and large size cuttings were measured by a 3D profilometer and a scanning electron microscope (SEM). Finally, the rock-breaking mechanism of the Stinger PDC cutter was illustrated. The results indicated that the cutting depth has the greatest influence on the cutting force and MSE, while the cutting speed has no obvious effects, especially at low cutting speeds. As the increase of cutting depth, the cutting force increases linearly, and MSE reduces with a quadratic polynomial relationship. When the cutting angle raises from 10° to 30°, the cutting force increases linearly, and the MSE firstly decreases and then increases. The optimal cutting angle for breaking rock is approximately 20°. The Stinger PDC cutter breaks granite mainly by high concentrated point loading and tensile failure, which can observably improve the rock breaking efficiency. The key findings of this work will help to reveal the rock-breaking mechanisms and optimize the cutter arrangement for the Stinger PDC cutter.

Preparation of multicore millimeter-sized spherical alginate capsules to specifically and sustainedly release fish oil

Specific and sustained release of nutrients from capsules to the gastrointestinal tract has attracted many attentions in the field of food and drug delivery.In this work,we reported a monoaxial dispersion electrospraying-ionotropic gelation technique to prepare multicore millimeter-sized spherical capsules for specific and sustained release of fish oil.The spherical capsules had diameters from 2.05 mm to 0.35 mm with the increased applied voltages.The capsules consisted of uniform(at applied voltages of≤10 k V)or nonuniform(at applied voltages of>10 k V)multicores.The obtained capsules had reasonable loading ratios(9.7%-6.3%)due to the multicore structure.In addition,the obtained capsules had specific and sustained release behaviors of fish oil into the small intestinal phase of in vitro gastrointestinal tract and small intestinal tract models.The simple monoaxial dispersion electrospraying-ionotropic gelatin technique does not involve complicated preparation formulations and polymer modification,which makes the technique has a potential application prospect for the fish oil preparations and the encapsulation of functional active substances in the field of food and drug industries.

Astrocyte evolution and human specificity

The cerebral cortex is one of the most complex structures of the mammalian central nervous system and accounts for the extraordinary cognitive abilities in primates and humans.Since the 19th century,neur ons have been believed to be the main players in the building of the brain,yet astrocytes also play a crucial role as fundamental building blocks of the cerebral cortex complexity.