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High-Voltage power Integrated Circuits (HVICs) are widely used to realize high-efficiency power conversions (e.g., AC/DC conversion), gate drivers for power devices and LED lighting, and so on. The Bipolar-CMOS-DMOS (BCD) process is proposed to fabricate devices with bipolar, CMOS, and DMOS modes, and thereby realize the single-chip integration of HVICs. The basic integrated technologies of HVICs include High-Voltage (HV) integrated device technology, HV interconnection technology, and isolation technology. The HV integrated device is the core of HVICs. The basic requirements of the HV integrated device are high breakdown voltage, low specific on-resistance, and process compatibility with low-voltage circuits. The REduced SURFace field (RESURF) technology and junction termination technology are developed to optimize the surface field of integration power devices and breakdown voltage. Furthermore, the ENhanced DIelectric layer Field (ENDIF) and REduced BULk Field (REBULF) technologies are proposed to optimize bulk fields. The double/triple RESURF technologies are further developed, and the superjunction concept is introduced to integrated power devices and to reduce the specific on-resistance. This work presents a comprehensive review of these technologies, including the innovation technologies of the authors' group, such as ENDIF and REBULF, substrate termination technology prospective integrated technologies and HVICs in wide band gap semiconductor materials are also discussed.

In this paper, a novel cut-off degradation of output current induced by high fluence neutron radiation is investigated for high-voltage silicon-on-insulator lateral double-diffused MOSFET (HV SOI LDMOS). Unlike low/middle fluence, severe current collapse occurs at low drain voltage. Combining experiments and energy band analysis, we reveal that a secondary charge removal effect leads to cut-off degradation, which is closely related to the field enhancement and high-density defects at high neutron fluence. Although the gate channel can be turned on after radiation, below drain threshold voltage (VDT), electron drift is blocked by a potential barrier caused by the local space charge region with low trap occupation rate, rather than the global impact at low fluence. In addition, the influences of structural parameters on the cut-off degradation and VDT are studied to guide the rad-hardening design of HV SOI LDMOS.

Total-ionizing-dose (TID) radiation response on unclosed edge termination is investigated for high voltage silicon-on-insulator (SOI) laterally diffused metal–oxide–semiconductor (LDMOS) in this article. Radiation-induced dual-channel leakage current model is proposed to reveal the mechanism of leakage current generation at OFF-state. Radiation causes a mass of positive oxide trapped charges generated in field oxide (FOX) layer and buried oxide layer. Owing to the P-SOI layer with significantly low doping concentration, two inversion channels are formed at the surface and bottom in the edge termination region, which provides parallel conduction paths. Electrons from the source N+ are pulled down and flow along the bottom channel while punchthrough occurring. The radiation-induced leakage current could be suppressed by thinning FOX layer, increasing the doping concentration of the P-SOI layer, and thickening the SOI layer.

Recently, Shu et al. published “Numerical and Experimental Investigation of TID Radiation Effect on the Breakdown Voltage of 400 V SOI NLDMOS.” This short article is an extension of that earlier article. The breakdown voltage of 400-V silicon-on-insulator n-channel laterally diffused metal–oxide semiconductor field-effect transistors with different drift region lengths are examined after exposure to total ionizing dose. The variation observed is analyzed using technology computer-aided design simulation.

A novel Homogenization Field Technology (HOFT) in lateral power devices is proposed and experimentally proved in this letter. By introducing the periodically discrete metal insulator semiconductor (MIS) structure, which realizes periodic equal potential and self-charge balance, the HOFT obtains almost uniform surface and bulk electric field distributions in the voltage sustaining layer. Therefore, the new device harvests both higher breakdown voltage V B and lower specific on-resistance R on,sp than those of the conventional reduced surface field (RESURF) technology in much higher and wider doping dose range. The experiment of the HOFT device realized a V B of 672 V and a R on,sp of 56.7 $\text{m}\Omega ~\cdot $ cm2 under a high doping dose of $5.6\times 10^{{12}}$ cm−2, which represents a reduction of 33.8% when compared with the theoretical value of the triple RESURF technology.

Titanium dioxide (TiO2) is one of the most promising candidates for photoelectrochemistry applications. For a high photoelectrochemistry performance, the control of crystal structure and crystal facet is essential. The phase transformation of TiO2 is conventionally achieved by thermal annealing. Here, we report an approach for selective phase transformation of TiO2 containing exposed reactive facets with improved photoelectrochemistry performance. After femtosecond laser processing, TiO2 nanotubes with exposed reactive anatase {010} facets are prepared, and they have a maximum photocurrent density more than 5 times that of pure anatase. Additionally, this strategy can induce phase transformation in a selective area, which shows the advantages of patterning processing. Our method constructs a promising strategy for preparing functional nanomaterials with high performances and functionality.

The electrical characteristics of silicon-on-insulator (SOI) n-channel laterally diffused metal oxide semiconductor field effect transistors (NLDMOSFETs) are examined after exposure to the total ionizing dose (TID). The devices are partially radiation hardened in that the gate oxide (GOX) and the field oxide (FOX) have undergone a hardening process, but not the buried oxide (BOX). Two bias conditions, OFF-state and all terminals grounded, during irradiation are examined. The irradiated device shows that the OFF-state leakage current ( $I_{L}$ ) of these devices increases with the accumulated dose. The physical mechanisms for the $I_{L}$ are analyzed by technology computer-aided design (TCAD) simulation. The OFF-state leakage current ( $I_{L}$ ) can be explained due to the effects of radiation-induced trapped charge at the BOX silicon interface.

Existing evidence has revealed inconsistent results on the association between metabolic syndrome (MetS) and endometrial cancer (EC) risk. Herein, we aim to better understand this association. Systematic searches of PubMed, EMBASE, and Web of Science through 12 December 2019 were conducted. Observational studies that provided risk estimates of MetS and EC risk were eligible. The quality of the included studies was judged based on the Newcastle-Ottawa scale. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Six studies, comprising 17,772 EC cases and 150,371 participants were included. MetS, diagnosed according to the criteria of the National Cholesterol Education Program-Third Adult Treatment Panel, was associated with an increased risk of EC (OR: 1.62; 95% CI = 1.26-2.07) with substantial heterogeneity (I2 = 78.3%). Furthermore, we found that women with MetS, diagnosed according to the criteria of the International Diabetes Federation, had a significantly higher risk of EC compared to healthy controls (OR: 1.45; 95% CI = 1.16-1.81; I2 = 64.6%). Our findings were generally consistent with the main results in the majority of prespecified subgroups, as well as in sensitivity analyses. In conclusion, MetS is associated with EC risk.

A shield gate trench MOSFET (SGTMOS) featuring narrow gate (NG) architecture and low-k dielectric layer (LDL), namely NL-SGTMOS, is proposed in this letter. By eliminating the middle portion of gate polysilicon without additional mask, and employing LDL between control gate and the grounded field plate (FP), the NL-SGTMOS can greatly reduce parasitic gate-to-plate capacitance induced by the FP, which is a common issue in conventional SGTMOS structure. T-CAD simulations and experiments are performed for evaluations of the proposed device. The fabricated 1-mm2 device (only with NG) achieved on-resistance of 4.57 $\text{m}\Omega $ and gate charge of 7.46 nC at gate voltage of 10 V, which show progressive performance among other existing technologies.

A novel high trigger current NPN transistor (HTC-NPN) with excellent double-snapback performance is developed in $0.5\mu \text{m}$ Bipolar CMOS DMOS (BCD) technology. A new floating N+ (FN) layer fabricated in drift-region not only induces two-stage snapback, but also achieves high trigger current ( ${I}_{\text {tr}}$ ) to provide ESD protection for high-voltage (HV) output port without being accidentally triggered on and latch-up like. The operational mechanism and the applied range of the HTC-NPN are discussed in detail, and the double-snapback process induced by the FN is explained via T-CAD simulation as well. From transmission line pulse (TLP) tested results, the proposed HTC-NPN achieved high ${I}_{\text {tr}}$ up to 1.5 A and controllable double-snapback characteristic, thus matching load line from HV output circuit well.

A depletion MOS controlled (DMC) current regulator diode (CRD) based on bipolar carrier transport mechanism is proposed and experimentally demonstrated in this paper. Compared with the conventional CRD based on unipolar junction field effect transistor, DMC CRD features a highly doped p-type substrate. On the one hand, the P+ substrate provides hole injection, which makes the output characteristics of DMC CRD resemble a PIN rectifier when operating in the linear region with a small anode voltage. Accordingly, DMC CRD gets a large slope of output characteristic to realize a lower knee voltage (VK) in comparison to the conventional CRD for a same anode current. On the other hand, the P+ substrate and N-type epitaxial layer can form a reverse PN junction to withstand a high reverse breakdown voltage, which allows DMC CRD to be applied in AC circuit. The initial experimental result demonstrates that a low VK of 1.2 V and a high reverse breakdown voltage (BVR) above 250 V are achieved in a 30-mA-level DMC CRD.

This paper proposed a novel integrated low capacitance transient voltage suppressor (ILC-TVS) for system-level Electrical Over Stress or Electro-Static discharge (EOS or ESD) protection. Compared with the regular TVS, the new one can be fabricated using standard bipolar technology and also possesses the good system-level ESD robustness. By a newly-proposed anode extension technology (AET), the input common-mode capacitance at "0 bias" state is suppressed from 0.78 pF down to 0.65 pF, which realizes the smoother capacitance curve with bias voltage increasing from 0~5 V. According to the standard EOS/ESD tests, the novel ILC-TVS gets the IEC 61000-4-5 EOS peak current (I PP ) of 5.26 A and endures the IEC 61000-4-2 contact mode ESD stress of ± 11 kV. Therefore, the ILC-TVS can provide robust ESD protection for high-speed data interface by on-chip or off-chip design.

In this work, a high-voltage (HV) junction field effect transistor (JFET) with voltage class extended to 800 V is proposed, which obtains a satisfactory on-state breakdown voltage (ON-BV) performance. For the traditional HV JFET, ON-BV is much lower than OFF-BV, which cannot meet the requirement for the application of high voltage start-up circuit. In pursuit of a high ON-BV and making it close to OFF-BV, a dilute-doped resistance region is introduced in the HV JFET to mitigate space-charge-modulation (SCM) effect without additional mask and area. By appropriately increasing the dose of Deep N-Well (DNW), ON-BV can be further increased without degrading OFF-BV. At last, the proposed JFET obtains a high OFF-BV of 900 V and a high ON-BV of 965 V without sacrificing the competitive current capacity above 0.11 mA/μm. Besides, the mechanism of power loss (P LOSS ) induced by substrate current (I SUB ) and gate current (I Gate ) during charging process is also revealed, which is associated with SCM. Benefit by the mitigation of SCM, I SUB +I Gate is reduced significantly in the proposed structure.

The forward-biased diode has been widely applied in electrostatic discharge (ESD) protection projects. In this Letter, various diodes with finger-shaped topology are studied by transmission line pulse (TLP) and emission microscope (EMMI) experiments. Among them, a novel mix-mode diode with P-well and floating deep N-well, called MMDIO, is fabricated by the same process and footprint, except that some discrete N+ regions are being added to the original anode P+ region. This approach forms a combination of a parasitic NPN transistor and a PNPN structure, which can significantly optimise the ESD current efficiency and clamping voltage (V CL). According to the comprehensive comparison, the MMDIO with overlapped anode N+ layout could endure the failure current 1.25 times higher than that of a regular diode under the same junction capacitance (C j), while the V CL is reduced by 20%. Accordingly, the MMDIO is an attractive solution to pass the higher ESD level without any negative influence.

Ablation of TiO2 surface using a double-pulse femtosecond laser was studied applying plasma model calculations and experimental work. The free electron decay time measured by using the double-pulse breakdown threshold method was 550 fs for TiO2. A plasma model is applied with the experimentally derived decay time constant for TiO2 surface ablation. The transient electron density evolution during the TiO2 surface ablation with a double-pulse femtosecond laser was calculated. The ablation experiment using a double-pulse femtosecond laser indicated that the ablation threshold depended on calculated electron density. Furthermore, ablated crater diameter near the threshold was found to depend on the laser fluence with a constant electron density.

Breakdown voltage (BV) shifting behavior induced by total-ionizing-dose (TID) irradiation is investigated for high-voltage SOI LDMOS, in this letter. The BV increase caused by irradiation is present for the first time, and the degradation mechanism is revealed by modeling and simulation. Irradiation-induced electric field modulation exerts an impact on the competition between the lateral BV and vertical BV and results in BV shifting. The dielectric field is enhanced by irradiation-induced positive oxide trapped charges in the BOX layer, which is responsible for the BV increasing after irradiation. A TID radiation hardening approach is proposed so that the lateral BV is required to be properly higher than vertical BV instead of pursuing equality.

Large quantities of solid wastes, including gangue (waste rock) have been added to the goafs in China’s coal mines as backfill. In this study, the mineral and chemical compositions of gangue from the No. 12 coal mine of the Pingdingshan Coal Group were investigated to determine potential pollution concerns, and the behaviour of contaminants in the gangue, such as salts, alkali metals, and alkaline earth metals, was explored using static immersion tests. COMSOL Multiphysics was used to study contaminant migration. The concentration and diffusion distance of metal ions were found to increase over time; this was negatively correlated with gangue particle size. Acidic environments promoted the dissolution of Ca, Fe, Mn, Na, Zn, Pb, and Be, while in alkaline environments, Se dissolution was accelerated.

SiC MOSFET with three-section edge termination is investigated in this paper. The edge termination for SiC MOSFET is divided into three sections with different field limited rings and the space between rings, which benefits to achieve uniform electric field and high breakdown voltage (BV). The degradation mechanism of BV and on-resistance during high temperature reverse bias (HTRB) and high temperature gate bias (HTGB) experiment are revealed. For HTRB, positive oxide trapped charge generation on SiC/SiO2 surface enhances the electric field peak at breakdown point, which is responsible for BV decreasing. For HTGB, negative oxide trapped charge generation on SiC/SiO2 surface is responsible for the increase of threshold voltage and on-resistance.

Background On 31 December 2019, the World Health Organization recognised clusters of pneumonia‐like cases due to a novel coronavirus disease (COVID‐19). COVID‐19 became a pandemic 71 days later. Aim To report the clinical and epidemiological features, laboratory data and outcomes of the first group of 11 returned travellers with COVID‐19 in Australia. Methods This is a retrospective, multi‐centre case series. All patients with confirmed COVID‐19 infection were admitted to tertiary referral hospitals in New South Wales, Queensland, Victoria and South Australia. Results The median age of our patient cohort was 42 years (IQR, 24–53 years) with six men and five women. Eight patients (72.7%) had returned from Wuhan, one from Shenzhen, one from Japan, and one from Europe. Possible human‐to‐human transmission from close family contacts in gatherings overseas occurred in two cases. Symptoms on admission were fever, cough and sore throat (n = 9, 81.8%). Co‐morbidities included hypertension (n = 3, 27.3%) and hypercholesterolaemia (n = 2, 18.2%). No patients developed severe acute respiratory distress nor required intensive care unit admission or mechanical ventilation. After a median hospital stay of 14.5 days (IQR, 6.75–21), all patients were discharged. Conclusions This is a historical record of the first COVID‐19 cases in Australia during the early biocontainment phase of the national response. These findings were invaluable for establishing early inpatient and outpatient COVID‐19 models of care and informing the management of COVID‐19 overtime as the outbreak evolved. Future research should extend this Australian case series to examine global epidemiological variation of this novel infection. This article is protected by copyright. All rights reserved.

Background SARS-CoV-2 poses a considerable threat to those living in residential aged care facilities (RACF). RACF COVID-19 outbreaks have been characterised by the rapid spread of infection and high rates of severe disease and associated mortality. Despite a growing body of evidence supporting airborne transmission of SARS-CoV-2, current infection control measures in RACF including hand hygiene, social distancing, and sterilisation of surfaces, focus on contact and droplet transmission. Germicidal ultraviolet (GUV) light has been used widely to prevent airborne pathogen transmission. Our aim is to investigate the efficacy of GUV technology in reducing the risk of SARS-CoV-2 infection in RACF. Methods A multicentre, two-arm double-crossover, randomised controlled trial will be conducted to determine the efficacy of GUV devices to reduce respiratory viral transmission in RACF, as an adjunct to existing infection control measures. The study will be conducted in partnership with three aged care providers in metropolitan and regional South Australia. RACF will be separated into paired within-site zones, then randomised to intervention order (GUV or control). The initial 6-week period will be followed by a 2-week washout before crossover to the second 6-week period. After accounting for estimated within-zone and within-facility correlations of infection, and baseline infection rates (10 per 100 person-days), a sample size of n = 8 zones (n = 40 residents/zone) will provide 89% power to detect a 50% reduction in symptomatic infection rate. The primary outcome will be the incidence rate ratio of combined symptomatic respiratory infections for intervention versus control. Secondary outcomes include incidence rates of hospitalisation for complications associated with respiratory infection; respiratory virus detection in facility air and fomite samples; rates of laboratory confirmed respiratory illnesses and genomic characteristics. Discussion Measures that can be deployed rapidly into RACF, that avoid the requirement for changes in resident and staff behaviour, and that are effective in reducing the risk of airborne SARS-CoV-2 transmission, would provide considerable benefit in safeguarding a highly vulnerable population. In addition, such measures might substantially reduce rates of other respiratory viruses, which contribute considerably to resident morbidity and mortality. Trial registration Australian and New Zealand Clinical Trials Registry ACTRN12621000567820 (registered on 14th May, 2021).

The distribution of radiation induced positive oxide trapped charges (N ot ) in buried oxide (BOX) with different applied electric fields for high-voltage (HV) SOI LDMOS is investigated. In contrast to the traditional model which depends upon N ot buildup near the interface that the field line points to, the verified experimental results in this work indicated that there are still a non-negligible set of N ot generated in SOI/BOX interface even if the electric field plays a negative role (field line perpendicular to the SOI/BOX interface pointing from the top to the bottom of the BOX). The improved model on BOX damage induced by TID considering this set of N ot and its saturation effect is proposed and adopted in accurate simulated analysis to predict the post-irradiation device behavior. The mechanism of HV SOI LDMOS degradation during irradiation is also revealed. The radiation hardening LDMOS in this work keeps breakdown voltage above 120 V at D=500 krad(Si).

A new narrow gate (NG) trench MOSFET with stepped field plate (SFP) and polysilicon bridge (PB), named NSP-MOSFET, is proposed and discussed in this paper. The SFP can smooth electric field profile along trench, thus improving doping concentration of epitaxial layer and reducing specific on-resistance (R ON,SP ). The NG reduces parasitic gate capacitance and gate charge (Q G ). In addition, the PB can partly offset the increase of internal gate resistance induced by the NG. T-CAD simulations are performed to evaluations of fundamental performances. Benefiting from structural improvements, the proposed device obtains about 22 % and 9.5 % reductions in R ON,SP ×Q G compared with conventional trench MOSFET and SFP trench MOSFET, respectively.

Background Mesenchymal stem cells (MSCs) represent a promising treatment option for acute kidney injury (AKI). The main drawbacks of MSCs therapy, including the lack of specific homing after systemic infusion and early cell death in the inflammatory microenvironment, directly affect the therapeutic efficacy of MSCs. Erythropoietin (EPO)-preconditioning of MSCs promotes their therapeutic effect, however, the underlying mechanism remains unknown. In this study, we sought to investigate the efficacy and mechanism of EPO in bone marrow derived mesenchymal stem cells (BMSCs) for AKI treatment. Results We found that incubation of BMSCs with ischemia/reperfusion(I/R)-induced AKI kidney homogenate supernatant (KHS) caused apoptosis in BMSCs, which was decreased by EPO pretreatment, indicating that EPO protected the cells from apoptosis. Further, we showed that EPO up-regulated silent information regulator 1 (SIRT1) and Bcl-2 expression and down-regulated p53 expression. This effect was partially reversed by SIRT1 siRNA intervention. The anti-apoptotic effect of EPO in pretreated BMSCs may be mediated through the SIRT1 pathway. In a rat AKI model, 24 h after intravenous infusion, GFP-BMSCs were predominantly located in the lungs. However, EPO pretreatment reduced the lung entrapment of BMSCs and increased their distribution in the target organs. AKI rats infused with EPO-BMSCs had significantly lower levels of serum IL-1β and TNF-α, and a significantly higher level of IL-10 as compared to rats infused with untreated BMSCs. The administration of EPO-BMSCs after reperfusion reduced serum creatinine, blood urea nitrogen, and pathological scores in I/R-AKI rats more effectively than BMSCs treatment did. Conclusions Our data suggest that EPO pretreatment enhances the efficacy of BMSCs to improve the renal function and pathological presentation of I/R-AKI rats.

Hot-hole induced burnout phenomenon in a high-voltage triple reduced surface field (RESURF) LDMOS with sandwich N-P-N layer is investigated in this work. The sandwich N-P-N structure is employed in the drift region of LDMOS to obtain a further optimized trade-off between specific on-resistance (R$_{on,sp}$) and breakdown voltage (BV). However, experimental results show that the BV drops in the off-state with a period time of 2.7 s and the device burns out. To solve this problem, the corresponding burnout mechanism is analyzed and its countermeasure is proposed and demonstrated by simulation and experiment. As a result, a competitive performance with a low R$_{on,sp}$ of $32.38 \mathrm{m}\Omega \cdot cm^{2}$ and a high BV of 535 V without burnout is achieved for the triple RESURF LDMOS with sandwich N-P-N layer.

Background: Mesenchymal stem cells (MSCs) represent a promising treatment option for acute kidney injury (AKI). The main drawbacks of MSCs therapy, including the lack of specific homing after systemic infusion and early cell death in the inflammatory microenvironment, directly affect the therapeutic efficacy of MSCs. Erythropoietin (EPO)-preconditioning of MSCs promotes their therapeutic effect; however, the underlying mechanism remains unknown. In this study, we sought to investigate the efficacy and mechanism of EPO in bone marrow mesenchymal stem cells (BMSCs) for AKI treatment.Results: We found that incubation of BMSCs with ischemia/reperfusion(I/R)-induced AKI kidney homogenate supernatant (KHS) caused apoptosis in BMSCs, which was decreased by EPO pretreatment, indicating that EPO protected the cells from apoptosis. Further, we showed that EPO up-regulated SIRT1 and Bcl-2 expression and down-regulated p53 expression. This effect was partially reversed by SIRT1 siRNA intervention. The anti-apoptotic effect of EPO in pretreated BMSCs may be mediated through the SIRT1 pathway. In a rat AKI model, 24 h after intravenous infusion, GFP-BMSCs were predominantly located in the lungs. However, EPO pretreatment reduced the lung entrapment of BMSCs and increased their distribution in the target organs. AKI rats infused with EPO-BMSCs had significantly lower levels of serum IL-1β and TNF-α, and a significantly higher level of IL-10 as compared to rats infused with untreated BMSCs. The administration of EPO-BMSCs after reperfusion reduced serum creatinine, blood urea nitrogen, and pathological scores in I/R-AKI rats more effectively than BMSCs treatment did.Conclusions: Our data suggest that EPO pretreatment enhances the efficacy of BMSCs to improve the renal function and pathological presentation of I/R-AKI rats.

Aim The aim of this paper is to clarify the inconsistent findings in the association between antidepressant use and the risk of epithelial ovarian cancer (EOC). Methods This study is a meta-analysis of observational studies retrieved from the PubMed, EMBASE, and Web of Science databases prior to August 15, 2017. Two researchers independently screened studies and extracted study characteristics and risk estimates. The odds ratios (OR) and 95% confidence intervals (CI) of EOC risk were summarized using an inverse variance weighted random-effects model. Heterogeneity between studies was assessed with the I2 statistic. Results Eight case–control studies involving 7878 EOC cases and 73 913 controls were identified. Compared with non-use, use of antidepressants was not significantly associated with EOC risk (summarized OR = 1.10, 95% CI: 0.91–1.32, I2 = 74.4%). Similar null results were also observed in the use of selective serotonin reuptake inhibitors (OR = 1.04, 95% CI = 0.80–1.35), tricyclic antidepressants (OR = 1.01, 95% CI = 0.79–1.30), and other antidepressant drugs (OR = 0.91, 95% CI = 0.74–1.12). Subgroup analyses of study characteristics, stratified by the type of control subjects, geographic location, exposure assessment, number of cases, and adjustment for potential confounders, showed that the ORs were broadly consistent across strata. The OR per 1 year-increment of duration was 0.99 (95% CI = 0.94–1.05, I2 = 40.0%, P = 0.154). Additionally, the OR for the greatest intensity of antidepressant use compared with never use was 0.82 (95% CI = 0.70–0.98, I2 = 0%, P = 0.489). Furthermore, no evidence of publication bias was detected through Funnel plots as well as Egger's and Begg's tests. Conclusions There is no association between antidepressant use and EOC risk. Further prospective studies are warranted to confirm these findings.

An ultra-low specific on-resistance 700 V lateral double-diffused MOSFET (LDMOS) with a buried super junction (BSJ) layer is proposed. [1–9] Buried P-pillars in the LDMOS can be depleted by neighboring N-pillars, overlying and underlying N-drift regions simultaneously, thus allowing a higher doping concentration. Consequently, the doping concentration of either the N-drift regions or N-pillars, or both, may also be increased therewith to compensate the surplus charges in the P-pillars. Compared with conventional surface super junction (SSJ) LDMOS, in which the super junction layer is implemented at the upper surface of the drift region, and P-pillars can only be depleted by the adjacent N-pillars and the N-drift regions beneath, the proposed novel LDMOS structure may have a lower specific on-resistance (Ron,sp) while maintain the same breakdown voltage (BV). Simulation results indicate that the Ron,sp of the novel structure is only 80.5 mΩ cm2 with a high BV of 750 V, which is reduced by 17% in comparison with the Ron,sp of a conventional SSJ LDMOS.

In this work, a split gate trench MOSFET (SGT) with shield layer (SL) is proposed to improve electrical characteristics. The SL modulates charge division of ionized donor atoms in drift region during depletion spreading. As a result, ionized donors electrically coupled to gate are dramatically reduced, thus lowering gate-drain charge (QGD). On the other hand, the SL structure increases energy band of channel region to address drain induced barrier lowering (DIBL) issue while maintaining a lower channel length and doping concentration. Significant reductions in on-resistance (RON), gate charge (QG), and total power losses are confirmed by simulations. The proposed SGT with SL achieves a switching figure of merit (RON × QG) of 30.46 mΩnC, which is 35.5% smaller than conventional trench MOSFET technology, but almost without impacting other fundamental parameters.

A novel superjunction (SJ) lateral double-diffused MOSFET (>950 V) with a thin layer SOI combining the advantage of low specific on-resistance ${R}_{\text {on,sp}}$ of the SJ and the high breakdown voltage ${V}_{\text {B}}$ of the thin SOI is proposed and experimentally demonstrated in this letter. Based on our previously developed equivalent substrate model, the optimized SJ endows the device with a respectably reduced ${R}_{\text {on,sp}}$ without sacrificing ${V}_{\text {B}}$ . Meanwhile, the thin layer SOI is designed with the enhanced dielectric layer field principle to carry out a high ${V}_{\text {B}}$ . The experimental results exhibit a ${R}_{\text {on,sp}}$ of 145 $\text{m}\Omega \cdot $ cm2 with a ${V}_{\text {B}}$ of 977 V. This represents a reduction in ${R}_{\text {on,sp}}$ by 18.1% when compared with the theoretical ${R}_{\text {on,sp}} \propto {V}_{\text {B}}^{{2.5}}\vphantom {^{^{^{^{}}}}}$ “silicon limit”.

Lean-oxygen environment caused by methane in high gassy coal mine goaf has a significant influence on the prediction index gases of residual coal spontaneous combustion. The coal sample from Xishan coalfield in China was used to conduct the low-temperature oxidation experiments under different lean-oxygen environments. The experimental results show that different lean-oxygen environments had a significant delay effect on the formation of CO, CO2, H2 and C2H6, and the lower the O2 concentration, the more obvious the delay effect, and the delay effect of methane was greater than that of N2. A lean-oxygen environment caused by methane also had a significant influence on the values of CO/ΔO2 ratio and CO2/ΔO2 ratio. However, when the temperature was T can be accurately expressed by exponential function. The absolute amount of CO, CO2 and C2H6 generated by 1 k g residual coal ( C CO , C CO 2 and C C 2 H 6 ), which can reduce the influence of air leakage and residual coal mass on prediction index gases, were introduced to predict the spontaneous combustion in high gassy coal mine goaf. Then, the distribution diagrams of C CO , C CO 2 and C C 2 H 6 with temperature and O2 concentration were obtained, so as to accurately predict the degree of spontaneous combustion in high gassy coal mine goaf. The research results are of great significance to the prevention of spontaneous combustion in goaf of high gassy mine.

Background We assessed replication and excretion of the live attenuated tetravalent dengue vaccine (CYD-TDV) into biological fluids following vaccination in dengue-naive adults in Australia. Methods Vaccinal viremia/shedding was assessed in a subset of participants enrolled in a lot-to-lot consistency study; 95 participants received 3 subcutaneous doses of CYD-TDV from phase 2/3 lots of the vaccine, and 8 received placebo; doses were administered 6 months apart. Quantitative reverse-transcription polymerase chain reaction (qR-PCR) analysis was used to initially detect the yellow fever virus (YFV) core protein gene in the backbone of CYD-TDV in serum, saliva and urine, followed by serotype-specific qRT-PCR analysis of samples positive for YFV by qRT-PCR (lower limit of detection, 5.16 GEq/mL). Results YFV viremia was detected by qRT-PCR in 69.5% of participants (66 of 95) who received CYD-TDV, mainly 6-14 days after injection 1. The serotypes detected were serotype 4 (in 68.2% of participants [45 of 95]), serotype 3 (in 19.7% [13 of 95]), and serotype 1 (in 12.1% [8 of 95]); serotype 2 was not detected. None of the placebo recipients had vaccinal viremia/shedding. No participants had detectable viral shedding into saliva at levels above the lower limit of quantitation. Two participants had low-level viral shedding (serotype 3) in urine (5.47 and 5.77 GEq/mL). None of the participants with viremia or shedding experienced concomitant fever. Conclusions Low-level vaccinal viremia may occur following vaccination with CYD-TDV, but this is not associated with any symptom or adverse event. Clinical trials registration NCT01134263.

3-D edge termination design and analytic model for specific on-resistance ( ${R}_{ \mathrm{\scriptscriptstyle ON},\text {sp}})$ versus breakdown voltage (BV) of a 700-V triple reduced surface field lateral double-diffused MOSFET (LDMOS) with n-type top layer are presented in this paper. To eliminate the premature avalanche breakdown induced by the electric field crowding and the local charge imbalance in the transition region of the source-centered edge termination structure, 3-D numerical simulations and experiments are performed to investigate two crucial parameters ${L}_{1}$ and ${L}_{2}$ in the layout of the transition region. It is observed that optimal electric field distribution is obtained and breakdown positions are transferred to the active region at ${L}_{1} = 30~\mu \text{m}$ and ${L}_{2} = 1~\mu \text{m}$ . On the other hand, an analytic model is developed to describe the relation between ${R}_{ \mathrm{\scriptscriptstyle ON},\text {sp}}$ and BV, which is obtained as ${R}_{ \mathrm{\scriptscriptstyle ON},\text {sp}} = 5.93 \times 10^{-6} \times 22({T}/298)^{1.7} \times \text {BV}^{2}$ and theoretically verifies that the fabricated device has achieved optimized ${R}_{ \mathrm{\scriptscriptstyle ON},\text {sp}}$ and BV. Compared with our previous paper, the LDMOS experimentally demonstrated improved performance with ${R}_{ \mathrm{\scriptscriptstyle ON},\text {sp}}$ of 86.49 $\text{m}\Omega ~\cdot $ cm2 and BV of 805 V, which is leading performance for the 700-V applications in published data.

The global optimization of the balanced symmetric vertical superjunction (VSJ) device is proposed based on the R-well model for the first time to realize the unique minimum specific on-resistance $R_{{\mathrm{\scriptscriptstyle ON},\mathrm {min}}}$ . The R-well model, which is originated from our previous VSJ mode theory, shows the relationship between $R_{{\mathrm{\scriptscriptstyle ON}}}$ and the doping concentration N under the given pillar width W and breakdown voltage $V_{B}$ . The global $R_{{\mathrm{\scriptscriptstyle ON}}}$ optimization is realized to obtain the design formulas of N and the pillar length $L_{d}$ . The calculated results are in good agreement with the simulations. It is demonstrated from the comparisons with the simulations and the existing experiments that the optimization in this paper realizes the unique $R_{{on,\mathrm {min}}}$ with a relationship of $R_{{\mathrm{\scriptscriptstyle ON}}}\propto V_{B}^{1.03}$ . The R-well model is also universal for other $R_{on}$ optimizations.

A novel lateral double-diffused metal–oxide semiconductor (LDMOS) with three-dimensional floating vertical field plate (3-D F-VFP) is proposed in this paper. The 3-D F-VFP LDMOS features a discrete pillar-type VFP array through the N-type drift region and the VFP pillars with the same distance from the source are connected to each other to realize the equal potential. In the off-state, the potential along the drift region are pinned by the series of equal-potential F-VFP rings and a new full-region depletion mode is introduced into the bulk of the device. Therefore, the highly doped drift region is depleted by the 3-D F-VFP, establishing a self-adaptive charge balance inside the drift region. In the on-state, the current flows through the gaps among all the F-VFP pillars, preventing the long current path and reducing the on resistance $\boldsymbol{R}_{\mathbf{on}}$ . A 3-D F-VFP LDMOS is experimentally implemented, which obtains a breakdown voltage $\boldsymbol{V}_{\mathbf{B}}$ of 630 V and a $\boldsymbol{R}_{\mathbf{on}}$ of $344.8\ \mathbf{\Omega}$ compared with 550 V and $722.5\ \mathbf{\Omega}$ of the device without the F-VFP. The measured saturation current of the 3-D F-VFP LDMOS is more than 4.5 times of that of the device without F-VFP.

The electrical characteristics variations of 400V SOI NLDMOS after exposure to total dose irradiation are discovered. The mechanisms of these variations are analyzed and confirmed by TCAD simulations.

A novel CMOS-process-compatible high-holding voltage silicon-controlled rectifier (HHV-SCR) for electrostatic discharge (ESD) protection is proposed and demonstrated by simulation and transmission line pulse (TLP) testing. The newly introduced hole (or electron) recombination region H-RR (or E-RR) not only recombines the minority carrier in parasitic PNP (or NPN) transistor base by N+ (or P+) layer, but provides the additional recombination to eliminate the surface avalanche carriers by newly added P+ (or N+) layer in H-RR (or E-RR), which brings about a further improvement of holding voltage (V h). Compared with the measured V h of 1.8 V of low-voltage triggered silicon-controlled rectifier (LVTSCR), the V h of HHV-SCR can be increased to 8.1 V while maintaining a sufficiently high failure current (I t2 > 2.6 A). An improvement of over four times in the figure of merit (FOM) is achieved.

Background Conditioned pain modulation (CPM) is impaired in people with chronic pain such as knee osteoarthritis (KOA). The purpose of this randomized, controlled clinical trial was to investigate whether strong electroacupuncture (EA) was more effective on chronic pain by strengthening the CPM function than weak EA or sham EA in patients with KOA. Methods In this multicenter, three-arm parallel, single-blind randomized controlled trial, 301 patients with KOA were randomly assigned. Patients were randomized into three groups based on EA current intensity: strong EA (> 2 mA), weak EA (

An ultra-low specific on-resistance (R on,sp) lateral double-diffused metal-oxide-semiconductor transistor (LDMOS) with enhanced dual-gate and partial P-buried layer is proposed and investigated in this paper. On-resistance analytical model for the proposed LDMOS is built to provide an in-depth insight into the relationship between the drift region resistance and the channel region resistance. N-buried layer is introduced under P-well to provide a low-resistance conduction path and reduce the resistance of the channel region significantly. Enhanced dual-gate structure is formed by N-buried layer while avoiding the vertical punch-through breakdown in off-state. Partial P-buried layer with optimized length is adopted under the N-drift region to extend vertical depletion region and relax the electric field peak in off-state, which enhances breakdown voltage (BV) with low drift region resistance. For the LDMOS with enhanced dual-gate and partial P-buried layer, the result shows that R on,sp is 8.5 mΩ·mm2 while BV is 43 V.

Single event burnout (SEB) of NLDMOSFETs on SOI initiated by pulsed laser irradiation is demonstrated for the first time. The sensitive region of the device for SEB and the effects of reverse voltage and laser energy are explored. The data indicate that the device is most sensitive to laser pulses in the drift region near the P-well. This is influenced by the electric field distribution in the drift region of the LDMOSFET at the time of the laser pulse. The SEB threshold depends on both the applied reverse voltage and the laser pulse energy. The laser pulse energy at a given reverse voltage required to initiate SEB is inversely proportional to the laser spot distance from the P-well. Simulation results for the device drain current following the radiation pulse indicate that the behavior of the npn parasitic bipolar transistor inherent in the LDMOS structure can explain the observations.

A novel triple reduced surface field (RESURF) lateral double-diffused metal oxide semiconductor field effect transistor (LDMOS) with partial linear variable doping (LVD) N-type top (N-top) layer is proposed in this paper. Compared with the conventional triple RESURF LDMOS, a partial LVD N-top layer is introduced in the surface of N-well, providing a low on-resistance conduction path and leading to an optimized surface electric field, which alleviates the inherent tradeoff between the breakdown voltage (BV) and specific on-resistance (Ron,sp). With the n-drift region length of 70 μm, the novel triple RESURF LDMOS obtains a high BV of 847 V and a low Ron,sp of 79 mΩ cm2 which are 76 V higher and 46 mΩ cm2 lower than those of the conventional triple RESURF LDMOS. Therefore, the novel triple RESURF LDMOS can greatly improve the tradeoff between BV and Ron,sp. Furthermore, compared with the other existing technologies in the high BV level, the novel triple RESURF LDMOS can achieve a highest figure of merit (FOM, defined as BV2/Ron,sp) of 9.08 MW/cm2 and the conventional RESURF silicon limits are broken.

Cost-effective mask-sharing technology for the 200 V silicon-on-insulator (SOI) lateral insulated gate bipolar transistor (LIGBT) and p-channel lateral double-diffused MOS (PLDMOS) are proposed in this paper. N-well and P-body implantations are shared as an N-buffer implantation of the LIGBT and P-buffer implantation of the PLDMOS, respectively, which reduces two masks compared with the conventional process. The structure and process parameters for LIGBT and PLDMOS with the new process are optimized by simulation to achieve good performance. The experimental results indicate that the LIGBT and PLDMOS using the new process maintain the same performance compared to the conventional devices.

A high-voltage thick layer SOI field p-channel LDMOS (pLDMOS) with multiple field plates based on 11-μm-thick silicon layer and 1-μm-thick buried oxide layer is presented in this paper. The thick gate oxide layer is formed by field oxide process to endure the high voltage between the source and gate electrodes. The field implant (FI) technology is adopted to eliminate channel discontinuity at the bird's beak region. Multiple field plates constructed by polysilicon and metal layer are adopted to modulate electric field distribution of the depleted drift region. The SOI field pLDMOS with off-state breakdown voltage (BV) of −240 V is experimentally realized, which can be widely used for simplifying the design of level shifting.

A novel low turnoff loss carrier stored (CS) silicon-on-insulator (SOI) lateral insulated gate bipolar transistor (LIGBT) with trench gate barrier (CS SOI TGLIGBT) is proposed. The proposed CS SOI TGLIGBT features a trench gate inserted between the pwell and n-drift. Firstly, the trench gate acts as a hole barrier to prevent the hole from injecting directly into pwell in the on-state, which introduces carrier stored effect and realizes a uniform carriers distribution in the n-drift region, resulting in a decrease of the on-state voltage drop (Von). Secondly, due to the carrier stored effect and the assisted depleted effect induced by the trench gate, large number of carriers can be quickly removed at the initial turnoff process, leading to a decrease of turnoff loss (Eoff). The influences of gate trench barrier on Von and Eoff are investigated. Simulation results show that the proposed CS SOI TGLIGBT can achieve a 59% lower Eoff compared with the conventional SOI trench gate LIGBT at the same Von of 1.15 V.

The back gate (BG) induced breakdown mechanisms for thin layer SOI Field P-channel LDMOS (FPLDMOS) are investigated in this paper. Surface breakdown, bulk breakdown and punch-through breakdown are discussed, revealing that the block capability depends on not drain voltage (Vd), but also BG voltage (VBG). For surface breakdown, the breakdown voltage (BVs) increases linearly with VBG increasing. An expression of BVs on VBG is given, providing a good fitting to measured and simulated results. Bulk breakdown with a low breakdown voltage is attributed to high VBG. VBG induces depletion in n-well, giving rise to punch-through breakdown. A design requirement for the thin layer SOI FPLDMOS is proposed that breakdown voltages for the three breakdown mechanisms are compelled to be higher than the supply voltage of switching IC.

A 700 V dual-buried-layer n-channel lateral double-diffused MOSFET (DB-nLDMOS) based on substrate termination technology (STT) is presented and experimentally demonstrated in this paper. The termination region is well analyzed and designed to avoid the premature avalanche breakdown caused by the curved junction. The 2-D and 3-D numerical simulations have been performed to optimize the three key parameters of $\Delta L_{1,}\Delta L_{2,}$ and $\Delta L_{3}$ which impact on breakdown voltage (BV) greatly in the termination region. The simulation results show that the electric field peak is reduced and premature avalanche breakdown is avoided at the curved abrupt p-well/n-well junction with the STT. The experimental results demonstrate that low $R_{{\mathrm{\scriptscriptstyle ON},\mathrm {sp}}}$ of 105.6 $\text{m}\Omega \cdot {\mathrm{ cm}}^{2}$ based on $L_{d}$ and high BV of 788 V are achieved by the DB-nLDMOS.

A new relationship between the specific ON-resistance $R_{\mathrm{\scriptscriptstyle ON}}$ and breakdown voltage $V_{B}$ for the balanced symmetric superjunction (SJ) device is presented to produce the lowest $R_{\mathrm{\scriptscriptstyle ON}}$ for a given $V_{B}$ . The design formulas, including the doping density NW and the drift length $L_{d}$ , are given for both the nonfull depletion (NFD) and the full depletion SJ devices with an introduction of the normalized $V_{B}$ factor $\eta $ . For the NFD SJ MOSFET, an $R_{\mathrm{\scriptscriptstyle ON}} \propto V_{B}^{1.03}$ relationship is obtained. The analytical results show good agreement with the numerical results.

An ultralow turn-OFF loss ( ${E} _{\mathrm{\scriptscriptstyle OFF}}$ ) silicon-on-insulator lateral insulated-gate bipolar transistor with a p-buried layer (PB SOI LIGBT) is first proposed. A universal ${E} _{\mathrm{\scriptscriptstyle OFF}}$ model during inductive load turn-OFF is set up, which reveals that low ${E} _{\mathrm{\scriptscriptstyle OFF}}$ can be achieved by reducing the total integral current charges, reducing the average anode voltage in the first phase and increasing the charge factor ${k}$ . Due to the large capacitance effect and extra hole extraction path induced by the PB, the three ideas for low ${E} _{\mathrm{\scriptscriptstyle OFF}}$ are demonstrated in the PB SOI LIGBT. Simulation results show that the PB SOI LIGBT can achieve an 85% lower ${E} _{\mathrm{\scriptscriptstyle OFF}}$ compared with the conventional SOI LIGBT based on 6- $\mu \text{m}$ SOI layer. Furthermore, the proposed ${E} _{\mathrm{\scriptscriptstyle OFF}}$ model can be applied to all the IGBTs, and it reveals the mechanism of low ${E} _{\mathrm{\scriptscriptstyle OFF}}$ of the IGBT with a superjunction structure during inductive load switching.

High-voltage (HV) integrated power devices are widely used in many applications, including alternating current/direct current (AC/DC) power converter, HV gate driver integrated circuit (IC) and light emitting diode (LED) driver IC, etc. Among these applications, AC/DC power converter is essential for almost all power systems operated in the DC conditions. As a power switch in the AC/DC converter, the fundamental performance requirement of these power devices is to withstand a high voltage of 500–900 V and simultaneously have a low power loss for its efficient conversion. Therefore, several device technologies have been proposed to realize a high breakdown voltage (BV) and a low specific on-resistance (Ron,sp), such as reduced surface field (RESURF) technology, lateral super-junction (SJ) structure, lateral insulated-gate bipolar transistor (LIGBT), integrated vertical structure and junction termination technology. In this paper, a comprehensive review of the development and prospect of these technologies in AC/DC switching application is presented. Furthermore, analytic Ron,sp-BV models for some typical device structures, the possible strategies of Bipolar - Complementary metal oxide semiconductor - Double-diffused metal oxide semiconductor (BCD) platform integrated with vertical SJ devices, partial silicon-on-insulator (SOI) BCD technology, low gate charge (Qg) HV integrated power devices and wide bandgap technology are also described.