The RC-IGBT（reverse conducting insulated gate bipolar transistor） is a new kind of power semiconductor device which has many advantages such as smaller chip size,higher power density,lower manufacturing cost,softer ...The RC-IGBT（reverse conducting insulated gate bipolar transistor） is a new kind of power semiconductor device which has many advantages such as smaller chip size,higher power density,lower manufacturing cost,softer turn off behavior,and better reliability.However,its performance has a number of drawbacks,such as the snap-back effect.In this paper,an introduction about the snap-back effect of the RC-IGBT is given firstly. Then the physical explanations are presented with two simplified models.After that,some numerical simulations are carried out to verify the correctness of the models.展开更多
A non-depletion floating layer silicon-on-insulator （NFL SOI） lateral double-diffused metal–oxide–semiconductor （LDMOS） is proposed and the NFL-assisted modulated field （NFLAMF） principle is investigated in th...A non-depletion floating layer silicon-on-insulator （NFL SOI） lateral double-diffused metal–oxide–semiconductor （LDMOS） is proposed and the NFL-assisted modulated field （NFLAMF） principle is investigated in this paper. Based on this principle, the floating layer can pin the potential for modulating bulk field. In particular, the accumulated high concentration of holes at the bottom of the NFL can efficiently shield the electric field of the SOI layer and enhance the dielectric field in the buried oxide layer （BOX）. At variation of back-gate bias, the shielding charges of NFL can also eliminate back-gate effects. The simulated results indicate that the breakdown voltage （BV） is increased from 315 V to 558 V compared to the conventional reduced surface field （RESURF） SOI （CSOI） LDMOS, yielding a 77% improvement. Furthermore, due to the field shielding effect of the NFL, the device can maintain the same breakdown voltage of 558 V with a thinner BOX to resolve the thermal problem in an SOI device.展开更多
The hysteresis effect in the output characteristics,originating from the floating body effect,has been measured in partially depleted（PD） silicon-on-insulator（SOI） MOSFETs at different back-gate biases.I D hystere...The hysteresis effect in the output characteristics,originating from the floating body effect,has been measured in partially depleted（PD） silicon-on-insulator（SOI） MOSFETs at different back-gate biases.I D hysteresis has been developed to clarify the hysteresis characteristics.The fabricated devices show the positive and negative peaks in the I D hysteresis.The experimental results show that the I D hysteresis is sensitive to the back gate bias in 0.13-渭m PD SOI MOSFETs and does not vary monotonously with the back-gate bias.Based on the steady-state Shockley-Read-Hall（SRH） recombination theory,we have successfully interpreted the impact of the back-gate bias on the hysteresis effect in PD SOI MOSFETs.展开更多
In this work, we use a 3-nm-thick Al0.64In0.36N back-barrier layer in In0.17Al0.83N/GaN high-electron mobility transistor （HEMT） to enhance electron confinement. Based on two-dimensional device simulations, the infl...In this work, we use a 3-nm-thick Al0.64In0.36N back-barrier layer in In0.17Al0.83N/GaN high-electron mobility transistor （HEMT） to enhance electron confinement. Based on two-dimensional device simulations, the influences of Al0.64In0.36N back-barrier on the direct-current （DC） and radio-frequency （RF） characteristics of InAlN/GaN HEMT are investigated, theoretically. It is shown that an effective conduction band discontinuity of approximately 0.5 eV is created by the 3-nm-thick Al0.64In0.36N back-barrier and no parasitic electron channel is formed. Comparing with the conventional InAlN/GaN HEMT, the electron confinement of the back-barrier HEMT is significantly improved, which allows a good immunity to short-channel effect （SCE） for gate length decreasing down to 60 nm （9-nm top barrier）. For a 70-nm gate length, the peak current gain cut-off frequency （fT） and power gain cut-off frequency （fmax） of the back-barrier HEMT are 172 GHz and 217 GHz, respectively, which are higher than those of the conventional HEMT with the same gate length.展开更多
This paper reports that a novel type of suspended ZnO nanowire field-effect transistors （FETs） were successfully fabricated using a photolithography process, and their electrical properties were characterized by I-V...This paper reports that a novel type of suspended ZnO nanowire field-effect transistors （FETs） were successfully fabricated using a photolithography process, and their electrical properties were characterized by I-V measurements. Single-crystalline ZnO nanowires were synthesized by a hydrothermal method, they were used as a suspended ZnO nanowire channel of back-gate field-effect transistors （FET）. The fabricated suspended nanowire FETs showed a pchannel depletion mode, exhibited high on-off current ratio of -10^5. When VDS = 2.5V, the peak transconductances of the suspended FETs were 0.396 μS, the oxide capacitance was found to be 1.547 fF, the pinch-off voltage VTH was about 0.6 V, the electron mobility was on average 50.17cm2/Vs. The resistivity of the ZnO nanowire channel was estimated to be 0.96 × 10^2 Ω cm at VGS = 0 V. These characteristics revealed that the suspended nanowire FET fabricated by the photolithography process had excellent performance. Better contacts between the ZnO nanowire and metal electrodes could be improved through annealing and metal deposition using a focused ion beam.展开更多
目的研究teach-back方法健康宣教对合并糖尿病手术患者的护理效果。方法选取2018年1-12月在该院行择期手术治疗的糖尿病患者100例。其中50例为对照组,实施常规护理,另外50例为观察组,在对照组基础上加入有效的teach-back方法健康宣教。...目的研究teach-back方法健康宣教对合并糖尿病手术患者的护理效果。方法选取2018年1-12月在该院行择期手术治疗的糖尿病患者100例。其中50例为对照组,实施常规护理,另外50例为观察组,在对照组基础上加入有效的teach-back方法健康宣教。对比两组患者健康教育知晓率、满意度、并发症发生率、血糖控制情况。结果观察组健康教育知晓率高于对照组,观察组并发症发生4例而对照组发生8例,观察组明显低于对照组。观察组患者满意度高于对照组。两组患者血糖控制情况的比较:入院时两组患者FPG、HbA1c、2 h PG差异无统计学意义(P>0.05),出院时观察组FPG、HbA1c、2 h PG分别明显低于对照组。结论健康宣教用于糖尿病手术患者中,明显减少了并发症的发生,利于血糖的控制,提高了患者的满意度,值得进一步推广。展开更多
目的观察培元养心法(背俞穴温针灸)治疗肾阳不足型膝关节退行性病变疗效。方法纳入肾阳不足型膝关节退行性病变患者80例,采取随机数字表法分为对照组40例与观察组40例,对照组接受膝关节置换术治疗,观察组在对照组治疗基础上结合培元养心...目的观察培元养心法(背俞穴温针灸)治疗肾阳不足型膝关节退行性病变疗效。方法纳入肾阳不足型膝关节退行性病变患者80例,采取随机数字表法分为对照组40例与观察组40例,对照组接受膝关节置换术治疗,观察组在对照组治疗基础上结合培元养心法(背俞穴温针灸)治疗,观察各组数据情况:疗效优良率、治疗前后中医证候积分变化、术后3 d及术后6 d、术后9 d患者的疼痛评分[视觉模拟疼痛评分法(Visual analogue scale,VAS)],治疗前后患者C反应蛋白(C-reactive protein,CRP)及肿瘤坏死因子α(Tumor necrosis factor-α,TNF-α)和白介素-6(Interleukin-6,IL-6)指标变化、治疗前后患者Lysholm膝关节量表评分变化、并发症发生率、治疗前、治疗2周及治疗4周身体健康评分(the MOS item short from health survey,SF-36)。结果观察组患者治疗效果优良率(95.00%,38/40)高于对照组(80.00%,32/40),差异有统计学意义(P<0.05);各组患者治疗后中医证候积分下降,炎症因子(CRP、TNF-α、IL-6)均显著下降,Lysholm膝关节量表总评分显著上升,观察组治疗后中医证候积分及炎症因子(CRP、TNF-α、IL-6)均低于对照组,Lysholm膝关节量表总评分高于对照组,差异有统计学意义(P<0.05);观察组患者术后3、6、9 d的VAS评分均比对照组更低,差异有统计学意义(P<0.05);对照组并发症率为20.00%(8/40),比观察组的5.00%(2/40)更低,差异有统计学意义(P<0.05);治疗2周及治疗4周后观察组患者的SF-36评分均高于对照组患者,差异有统计学意义(P<0.05)。结论培元养心法(背俞穴温针灸)治疗肾阳不足型膝关节退行性病变疗效良好,患者症状改善,膝关节功能改善,并发症少,治疗安全可靠,且患者治疗后身体健康好转,值得应用。展开更多
基金Project supported by the National Major Science and Technology Special Project of China(No.2011ZX02504-002)
文摘The RC-IGBT（reverse conducting insulated gate bipolar transistor） is a new kind of power semiconductor device which has many advantages such as smaller chip size,higher power density,lower manufacturing cost,softer turn off behavior,and better reliability.However,its performance has a number of drawbacks,such as the snap-back effect.In this paper,an introduction about the snap-back effect of the RC-IGBT is given firstly. Then the physical explanations are presented with two simplified models.After that,some numerical simulations are carried out to verify the correctness of the models.
文摘A non-depletion floating layer silicon-on-insulator （NFL SOI） lateral double-diffused metal–oxide–semiconductor （LDMOS） is proposed and the NFL-assisted modulated field （NFLAMF） principle is investigated in this paper. Based on this principle, the floating layer can pin the potential for modulating bulk field. In particular, the accumulated high concentration of holes at the bottom of the NFL can efficiently shield the electric field of the SOI layer and enhance the dielectric field in the buried oxide layer （BOX）. At variation of back-gate bias, the shielding charges of NFL can also eliminate back-gate effects. The simulated results indicate that the breakdown voltage （BV） is increased from 315 V to 558 V compared to the conventional reduced surface field （RESURF） SOI （CSOI） LDMOS, yielding a 77% improvement. Furthermore, due to the field shielding effect of the NFL, the device can maintain the same breakdown voltage of 558 V with a thinner BOX to resolve the thermal problem in an SOI device.
基金Project supported by the TCAD Simulation and SPICE Modeling of 0.13μm SOI Technology,China (Grant No. 2009ZX02306-002)
文摘The hysteresis effect in the output characteristics,originating from the floating body effect,has been measured in partially depleted（PD） silicon-on-insulator（SOI） MOSFETs at different back-gate biases.I D hysteresis has been developed to clarify the hysteresis characteristics.The fabricated devices show the positive and negative peaks in the I D hysteresis.The experimental results show that the I D hysteresis is sensitive to the back gate bias in 0.13-渭m PD SOI MOSFETs and does not vary monotonously with the back-gate bias.Based on the steady-state Shockley-Read-Hall（SRH） recombination theory,we have successfully interpreted the impact of the back-gate bias on the hysteresis effect in PD SOI MOSFETs.
基金supported by the Natural Science Foundation of Hebei Province,China(Grant No.F2013202256)
文摘In this work, we use a 3-nm-thick Al0.64In0.36N back-barrier layer in In0.17Al0.83N/GaN high-electron mobility transistor （HEMT） to enhance electron confinement. Based on two-dimensional device simulations, the influences of Al0.64In0.36N back-barrier on the direct-current （DC） and radio-frequency （RF） characteristics of InAlN/GaN HEMT are investigated, theoretically. It is shown that an effective conduction band discontinuity of approximately 0.5 eV is created by the 3-nm-thick Al0.64In0.36N back-barrier and no parasitic electron channel is formed. Comparing with the conventional InAlN/GaN HEMT, the electron confinement of the back-barrier HEMT is significantly improved, which allows a good immunity to short-channel effect （SCE） for gate length decreasing down to 60 nm （9-nm top barrier）. For a 70-nm gate length, the peak current gain cut-off frequency （fT） and power gain cut-off frequency （fmax） of the back-barrier HEMT are 172 GHz and 217 GHz, respectively, which are higher than those of the conventional HEMT with the same gate length.
文摘This paper reports that a novel type of suspended ZnO nanowire field-effect transistors （FETs） were successfully fabricated using a photolithography process, and their electrical properties were characterized by I-V measurements. Single-crystalline ZnO nanowires were synthesized by a hydrothermal method, they were used as a suspended ZnO nanowire channel of back-gate field-effect transistors （FET）. The fabricated suspended nanowire FETs showed a pchannel depletion mode, exhibited high on-off current ratio of -10^5. When VDS = 2.5V, the peak transconductances of the suspended FETs were 0.396 μS, the oxide capacitance was found to be 1.547 fF, the pinch-off voltage VTH was about 0.6 V, the electron mobility was on average 50.17cm2/Vs. The resistivity of the ZnO nanowire channel was estimated to be 0.96 × 10^2 Ω cm at VGS = 0 V. These characteristics revealed that the suspended nanowire FET fabricated by the photolithography process had excellent performance. Better contacts between the ZnO nanowire and metal electrodes could be improved through annealing and metal deposition using a focused ion beam.
文摘目的研究teach-back方法健康宣教对合并糖尿病手术患者的护理效果。方法选取2018年1-12月在该院行择期手术治疗的糖尿病患者100例。其中50例为对照组,实施常规护理,另外50例为观察组,在对照组基础上加入有效的teach-back方法健康宣教。对比两组患者健康教育知晓率、满意度、并发症发生率、血糖控制情况。结果观察组健康教育知晓率高于对照组,观察组并发症发生4例而对照组发生8例,观察组明显低于对照组。观察组患者满意度高于对照组。两组患者血糖控制情况的比较:入院时两组患者FPG、HbA1c、2 h PG差异无统计学意义(P>0.05),出院时观察组FPG、HbA1c、2 h PG分别明显低于对照组。结论健康宣教用于糖尿病手术患者中,明显减少了并发症的发生,利于血糖的控制,提高了患者的满意度,值得进一步推广。
文摘目的观察培元养心法(背俞穴温针灸)治疗肾阳不足型膝关节退行性病变疗效。方法纳入肾阳不足型膝关节退行性病变患者80例,采取随机数字表法分为对照组40例与观察组40例,对照组接受膝关节置换术治疗,观察组在对照组治疗基础上结合培元养心法(背俞穴温针灸)治疗,观察各组数据情况:疗效优良率、治疗前后中医证候积分变化、术后3 d及术后6 d、术后9 d患者的疼痛评分[视觉模拟疼痛评分法(Visual analogue scale,VAS)],治疗前后患者C反应蛋白(C-reactive protein,CRP)及肿瘤坏死因子α(Tumor necrosis factor-α,TNF-α)和白介素-6(Interleukin-6,IL-6)指标变化、治疗前后患者Lysholm膝关节量表评分变化、并发症发生率、治疗前、治疗2周及治疗4周身体健康评分(the MOS item short from health survey,SF-36)。结果观察组患者治疗效果优良率(95.00%,38/40)高于对照组(80.00%,32/40),差异有统计学意义(P<0.05);各组患者治疗后中医证候积分下降,炎症因子(CRP、TNF-α、IL-6)均显著下降,Lysholm膝关节量表总评分显著上升,观察组治疗后中医证候积分及炎症因子(CRP、TNF-α、IL-6)均低于对照组,Lysholm膝关节量表总评分高于对照组,差异有统计学意义(P<0.05);观察组患者术后3、6、9 d的VAS评分均比对照组更低,差异有统计学意义(P<0.05);对照组并发症率为20.00%(8/40),比观察组的5.00%(2/40)更低,差异有统计学意义(P<0.05);治疗2周及治疗4周后观察组患者的SF-36评分均高于对照组患者,差异有统计学意义(P<0.05)。结论培元养心法(背俞穴温针灸)治疗肾阳不足型膝关节退行性病变疗效良好,患者症状改善,膝关节功能改善,并发症少,治疗安全可靠,且患者治疗后身体健康好转,值得应用。
