A novel structure is proposed for doubling the vertical breakdown voltage of silicon-on-insulator（SOI） devices. In this new structure, the conventional buried oxide（BOX） in an SOI device is split into two sections...A novel structure is proposed for doubling the vertical breakdown voltage of silicon-on-insulator（SOI） devices. In this new structure, the conventional buried oxide（BOX） in an SOI device is split into two sections： the source-section BOX and the drain-section BOX. A highly-doped Si layer, referred to as a non-depletion potential-clamped layer（NPCL）, is positioned under and close to the two BOX sections. In the split BOXes and the Si region above the BOXes, the blocking voltage（BV） is divided into two parts by the NPCL. The voltage in the NPCL is clamped to be nearly half of the drain voltage. When the drain voltage approaches a breakdown value, the voltage sustained by the source-section BOX and the Si region under the source are nearly the same as the voltage sustained by the drain-section BOX and the Si region under the drain. The vertical BV is therefore almost doubled. The effectiveness of this new structure was verified for a P-channel SOI lateral double-diffused metal-oxide semiconductor（LDMOS） and can be applied to other high-voltage SOI devices. The simulation results show that the BV in an NPCL P-channel SOI LDMOS is improved by 55% and the specific on-resistance（Ron,sp） is reduced by 69% in comparison to the conventional structure.展开更多
A novel low specific on-resistance （Ron,sp） silicon-on-insulator （SO1） p-channel lateral double-diffused metal-oxide semiconductor （pLDMOS） compatible with high voltage （HV） n-channel LDMOS （nLDMOS） is propo...A novel low specific on-resistance （Ron,sp） silicon-on-insulator （SO1） p-channel lateral double-diffused metal-oxide semiconductor （pLDMOS） compatible with high voltage （HV） n-channel LDMOS （nLDMOS） is proposed. The pLDMOS is built in the N-type SO1 layer with a buried P-type layer acting as a current conduction path in the on-state （BP SOl pLD- MOS）. Its superior compatibility with the HV nLDMOS and low voltage （LV） complementary metal-oxide semiconductor （CMOS） circuitry which are formed on the N-SOl layer can be obtained. In the off-state the P-buried layer built in the NSOI layer causes multiple depletion and electric field reshaping, leading to an enhanced （reduced） surface field （RESURF） effect. The proposed BP SO1 pLDMOS achieves not only an improved breakdown voltage （BV） but also a significantly reduced Ron,sp. The BV of the BP SO1 pLDMOS increases to 319 V from 215 V of the conventional SO1 pLDMOS at the same half cell pitch of 25 μm, and Ron,sp decreases from 157 mΩ.cm2 to 55 mΩ.cm2. Compared with the PW SO1 pLDMOS, the BP SO1 pLDMOS also reduces the Ron,sp by 34% with almost the same BV.展开更多
This paper discusses the breakdown mechanism and proposes a new simulation and test method of breakdown voltage （BV） for an ultra-high-voltage （UHV） high-side thin layer silicon-on-insulator （SOI） p-channel low-...This paper discusses the breakdown mechanism and proposes a new simulation and test method of breakdown voltage （BV） for an ultra-high-voltage （UHV） high-side thin layer silicon-on-insulator （SOI） p-channel low-density metal- oxide semiconductor （LDMOS）. Compared with the conventional simulation method, the new one is more accordant with the actual conditions of a device that can be used in the high voltage circuit. The BV of the SOI p-channel LDMOS can be properly represented and the effect of reduced bulk field can be revealed by employing the new simulation method. Simulation results show that the off-state （on-state） BV of the SOI p-channel LDMOS can reach 741 （620） V in the 3μm-thick buried oxide layer, 50μm-length drift region, and at -400 V back-gate voltage, enabling the device to be used in a 400 V UHV integrated circuit.展开更多
Negative Bias Temperature Instability （NBTI） has become one of the most serious reliability problems of metaloxide-semiconductor field-effect transistors （MOSFETs）. The degradation mechanism and model of NBTI are ...Negative Bias Temperature Instability （NBTI） has become one of the most serious reliability problems of metaloxide-semiconductor field-effect transistors （MOSFETs）. The degradation mechanism and model of NBTI are studied in this paper. From the experimental results, the exponential value 0.25-0.5 which represents the relation of NBTI degradation and stress time is obtained. Based on the experimental results and existing model, the reaction-diffusion model with H^＋ related species generated is deduced, and the exponent 0.5 is obtained. The results suggest that there should be H^＋ generated in the NBTI degradation. With the real time method, the degradation with an exponent 0.5 appears clearly in drain current shift during the first seconds of stress and then verifies that H^＋ generated during NBTI stress.展开更多
The influence of rheological parameters on vortex dynamics and the extent of drag reduction (DR) were deciphered via extensively analyzing the hi-fidelity direct numerical simulation results of the turbulent channel f...The influence of rheological parameters on vortex dynamics and the extent of drag reduction (DR) were deciphered via extensively analyzing the hi-fidelity direct numerical simulation results of the turbulent channel flow with polymer solutions. It has been observed that in all drag reduction regimes from the onset of DR to maximum drag reduction (MDR) limit, the Deborah number is defined as the product of an effective Weissenberg number, and the root mean square streamwise vorticity fluctuation remains O(1) in the near wall region. The ratio of the average lifetime of axial vortices to the vortex rotating duration decreases with increasing DR, and MDR is achieved when these time scales become nearly equal. Based on these observations a simple framework is proposed adequately to describe the influence of polymer additives on the extent of DR from onset to MDR as well as the universality of the MDR in flow systems with polymer additives.展开更多
Previous voltage clamp studies have demonstrated the modulation of sperm Ca 2+ activated K + (KCa) channels expressed in Xenopus oocytes by angiotensin II (Ang II) and extracellular ATP via AT 1 receptor and ...Previous voltage clamp studies have demonstrated the modulation of sperm Ca 2+ activated K + (KCa) channels expressed in Xenopus oocytes by angiotensin II (Ang II) and extracellular ATP via AT 1 receptor and P 2U receptor, respectively. In the present study, we investigated the involvement of KCa channels in receptor regulated sperm motility of the rat using a computer aided sperm analysis system, HTM IVOS, in conjunction with Ca 2+ mobilizing agents, receptor agonists/antagonists and KCa channels blockers. The percentage of motile sperm was increased by ionomycin (0.5 μmol/L), which could be inhibited by K + channel blockers, tetraethylammonium (TEA 1 μmol/L ) or charybdotoxin (ChTX, 300 nmol/L) indicating the presence of KCa channels. Ang II, at low concentration, 10 nmol/L, was found to increase motility, however, at higher concentration, 1 μmol/L, percentage of motility was found to be suppressed. Both stimulatory and inhibitory effects of Ang II could be reversed by losartan, a specific antagonist of AT 1 receptors, but not AT 2 antagonist PD123177, indicating the involvement of AT 1 but not AT2 receptor in mediating both effects. ChTX also abolished both stimulatory and inhibitory effects of Ang II, suggesting the involvement of KCa channels. The percentage of motility was also enhanced by extracellular ATP, a factor known to be involved in sperm activation. The ATP enhanced sperm motility was mimicked by UTP, and inhibited by ChTX and reactive blue, an antagonist of P 2 receptor, indicating the involvement of both P 2U and KCa channels. RT PCR study was also conducted to confirm the expression of KCa channels, AT 1 receptors and P 2U receptor, but not AT 2 receptor, in rat caudal epididymal sperm. The present findings suggest an important role of KCa channels in the regulation of sperm motility by AT 1 and P 2U receptors.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.61404110)the National Higher-Education Institution General Research and Development Project,China(Grant No.2682014CX097)
文摘A novel structure is proposed for doubling the vertical breakdown voltage of silicon-on-insulator（SOI） devices. In this new structure, the conventional buried oxide（BOX） in an SOI device is split into two sections： the source-section BOX and the drain-section BOX. A highly-doped Si layer, referred to as a non-depletion potential-clamped layer（NPCL）, is positioned under and close to the two BOX sections. In the split BOXes and the Si region above the BOXes, the blocking voltage（BV） is divided into two parts by the NPCL. The voltage in the NPCL is clamped to be nearly half of the drain voltage. When the drain voltage approaches a breakdown value, the voltage sustained by the source-section BOX and the Si region under the source are nearly the same as the voltage sustained by the drain-section BOX and the Si region under the drain. The vertical BV is therefore almost doubled. The effectiveness of this new structure was verified for a P-channel SOI lateral double-diffused metal-oxide semiconductor（LDMOS） and can be applied to other high-voltage SOI devices. The simulation results show that the BV in an NPCL P-channel SOI LDMOS is improved by 55% and the specific on-resistance（Ron,sp） is reduced by 69% in comparison to the conventional structure.
基金supported by the National Natural Science Foundation of China (Grant No. 61176069)the State Key Laboratory Science Fund of Electronic Thin Films and Integrated Devices of China (Grant No. CXJJ201004)the National Key Laboratory Science Fund of Analog Integrated Circuit,China (Grant No. 9140C090304110C0905)
文摘A novel low specific on-resistance （Ron,sp） silicon-on-insulator （SO1） p-channel lateral double-diffused metal-oxide semiconductor （pLDMOS） compatible with high voltage （HV） n-channel LDMOS （nLDMOS） is proposed. The pLDMOS is built in the N-type SO1 layer with a buried P-type layer acting as a current conduction path in the on-state （BP SOl pLD- MOS）. Its superior compatibility with the HV nLDMOS and low voltage （LV） complementary metal-oxide semiconductor （CMOS） circuitry which are formed on the N-SOl layer can be obtained. In the off-state the P-buried layer built in the NSOI layer causes multiple depletion and electric field reshaping, leading to an enhanced （reduced） surface field （RESURF） effect. The proposed BP SO1 pLDMOS achieves not only an improved breakdown voltage （BV） but also a significantly reduced Ron,sp. The BV of the BP SO1 pLDMOS increases to 319 V from 215 V of the conventional SO1 pLDMOS at the same half cell pitch of 25 μm, and Ron,sp decreases from 157 mΩ.cm2 to 55 mΩ.cm2. Compared with the PW SO1 pLDMOS, the BP SO1 pLDMOS also reduces the Ron,sp by 34% with almost the same BV.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60906038)
文摘This paper discusses the breakdown mechanism and proposes a new simulation and test method of breakdown voltage （BV） for an ultra-high-voltage （UHV） high-side thin layer silicon-on-insulator （SOI） p-channel low-density metal- oxide semiconductor （LDMOS）. Compared with the conventional simulation method, the new one is more accordant with the actual conditions of a device that can be used in the high voltage circuit. The BV of the SOI p-channel LDMOS can be properly represented and the effect of reduced bulk field can be revealed by employing the new simulation method. Simulation results show that the off-state （on-state） BV of the SOI p-channel LDMOS can reach 741 （620） V in the 3μm-thick buried oxide layer, 50μm-length drift region, and at -400 V back-gate voltage, enabling the device to be used in a 400 V UHV integrated circuit.
基金supported by the Fundamental Research Funds in Xidian Universities (Grant No.JY10000904009)the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (Grant No.2007BAK25B03)
文摘Negative Bias Temperature Instability （NBTI） has become one of the most serious reliability problems of metaloxide-semiconductor field-effect transistors （MOSFETs）. The degradation mechanism and model of NBTI are studied in this paper. From the experimental results, the exponential value 0.25-0.5 which represents the relation of NBTI degradation and stress time is obtained. Based on the experimental results and existing model, the reaction-diffusion model with H^＋ related species generated is deduced, and the exponent 0.5 is obtained. The results suggest that there should be H^＋ generated in the NBTI degradation. With the real time method, the degradation with an exponent 0.5 appears clearly in drain current shift during the first seconds of stress and then verifies that H^＋ generated during NBTI stress.
基金Project (10672069) supported by the National Natural Science Foundation of China
文摘The influence of rheological parameters on vortex dynamics and the extent of drag reduction (DR) were deciphered via extensively analyzing the hi-fidelity direct numerical simulation results of the turbulent channel flow with polymer solutions. It has been observed that in all drag reduction regimes from the onset of DR to maximum drag reduction (MDR) limit, the Deborah number is defined as the product of an effective Weissenberg number, and the root mean square streamwise vorticity fluctuation remains O(1) in the near wall region. The ratio of the average lifetime of axial vortices to the vortex rotating duration decreases with increasing DR, and MDR is achieved when these time scales become nearly equal. Based on these observations a simple framework is proposed adequately to describe the influence of polymer additives on the extent of DR from onset to MDR as well as the universality of the MDR in flow systems with polymer additives.
基金Direct Grant of the Chinese University of Hong Kong to Dr. HC Chan
文摘Previous voltage clamp studies have demonstrated the modulation of sperm Ca 2+ activated K + (KCa) channels expressed in Xenopus oocytes by angiotensin II (Ang II) and extracellular ATP via AT 1 receptor and P 2U receptor, respectively. In the present study, we investigated the involvement of KCa channels in receptor regulated sperm motility of the rat using a computer aided sperm analysis system, HTM IVOS, in conjunction with Ca 2+ mobilizing agents, receptor agonists/antagonists and KCa channels blockers. The percentage of motile sperm was increased by ionomycin (0.5 μmol/L), which could be inhibited by K + channel blockers, tetraethylammonium (TEA 1 μmol/L ) or charybdotoxin (ChTX, 300 nmol/L) indicating the presence of KCa channels. Ang II, at low concentration, 10 nmol/L, was found to increase motility, however, at higher concentration, 1 μmol/L, percentage of motility was found to be suppressed. Both stimulatory and inhibitory effects of Ang II could be reversed by losartan, a specific antagonist of AT 1 receptors, but not AT 2 antagonist PD123177, indicating the involvement of AT 1 but not AT2 receptor in mediating both effects. ChTX also abolished both stimulatory and inhibitory effects of Ang II, suggesting the involvement of KCa channels. The percentage of motility was also enhanced by extracellular ATP, a factor known to be involved in sperm activation. The ATP enhanced sperm motility was mimicked by UTP, and inhibited by ChTX and reactive blue, an antagonist of P 2 receptor, indicating the involvement of both P 2U and KCa channels. RT PCR study was also conducted to confirm the expression of KCa channels, AT 1 receptors and P 2U receptor, but not AT 2 receptor, in rat caudal epididymal sperm. The present findings suggest an important role of KCa channels in the regulation of sperm motility by AT 1 and P 2U receptors.
