Heteromaterial-gate line tunnel field-effect transistor based on Si/Ge heterojunction

A Si/Ge heterojunction line tunnel field-effect transistor(LTFET) with a symmetric heteromaterial gate is proposed.Compared to single-material-gate LTFETs, the heteromaterial gate LTFET shows an off-state leakage current that is three orders of magnitude lower, and steeper subthreshold characteristics, without degradation in the on-state current. We reveal that these improvements are due to the induced local potential barrier, which arises from the energy-band profile modulation effect. Based on this novel structure, the impacts of the physical parameters of the gap region between the pocket and the drain, including the work-function mismatch between the pocket gate and the gap gate, the type of dopant, and the doping concentration, on the device performance are investigated. Simulation and theoretical calculation results indicate that the gap gate material and n-type doping level in the gap region should be optimized simultaneously to make this region fully depleted for further suppression of the off-state leakage current.     

Ta和TaN底电极对原子层淀积HfO2介质MIM电性能的影响

以Ta,TaN为衬底,采用原子层淀积方法制备高介电常数HfO₂介质,比较研究了不同衬底电极对金属-绝缘体-金属（MIM）电容的性能影响.结果表明,采用TaN底电极能够获得较高的电容密度和较小的电容电压系数（VCC）,在1MHz下的其电容密度为7.47fF/μm²,VCC为356ppm/V²和493ppm/V,这归因于TaN底电极与HfO₂介质之间良好的界面特性.两种电容在3?V时漏电流为5×10^-8关键词： 高介电常数 MIM电容 2薄膜')" href="#">HfO₂薄膜 电极     

聚酯酰亚胺三元共聚物的核磁共振波谱法表征

用一维1H NMR、13C NMR方法研究了以N,N′-己二撑-1,6-双苯偏三酸酰亚胺二酸(IA6)、6-羟基-2-萘甲酸(HNA)和4,4′-二羟基二苯酮(DHBP)为单体的一种液晶聚酯酰亚胺三元共聚物的结构,并通过DEPT(无畸变极化转移增益法)、1H-1H COSY(氢-氢化学位移相关谱)、HMQC(异核多量子相关谱)、HMBC(异核多键相关谱)进一步确定了该类共聚物的1H谱和13C谱中各谱峰的归属,为研究热致性液晶聚酯酰亚胺共聚物的链结构和链序列提供了有价值的结构分析数据。     

正常内耳内听道磁共振水成像观测

运用磁共振水成像，观察和测量正常内耳内听道解剖，并比较不同性别、侧别间的差异．对40例（80耳）听力正常志愿者行内耳内听道三维快速自旋回波序列3D．FSE序列扫描，对数据作三维容积再现（3DVR）和多平面重建（MPR）处理、观察及测量，统计归纳并比较左右侧别间男女性别间的差异．40例（80耳）的内耳内听道均能100％显示，取得半规管高度、管径、跨度、弧长、蜗底宽度、耳蜗高度等20项内耳内听道指标测量数据，除外半规管高度、后半规管高度及后半规管弧长在男女性别间差异有显著性意义（P〈0．05）外，其余17项测量数据差异均无显著性意义（P〉0．05）．运用磁共振3D—FSE序列扫描，经3DVR或MPR图像处理后，能清晰显示内耳内听道解剖结构和精确测量解剖数据．左右侧别间无差异，男女性别间个别数据差异有待进一步论证和研究．     

介电常数近零模式与表面等离激元模式耦合实现宽带光吸收

介电常数为零或近零模式在微纳结构中提供了一个新的方式调控光与物质的相互作用.本文首先利用金属圆盘阵列结构激发了表面等离激元共振,在共振频率处实现了光的局域效果;然后通过在金属-绝缘体-金属超表面微纳结构中加入掺杂半导体材料,利用上层金属圆盘阵列激发的表面等离激元共振诱导介电常数近零模式的产生,从而使得介电常数近零模式与表面等离激元模式发生耦合,在中红外波段实现了一个470 nm的宽带吸收效果;数值模拟结果显示,在宽带吸收处存在光场的强局域效果.与窄带吸收相比,宽带吸收有更广泛的应用,比如吸收器、传感器、滤波器、微测辐射热计、光电探测器、相干热发射器、太阳能电池、指纹识别和能量收集装置等.     

Nonvolatile Memory Characteristics with Embedded High Density Ruthenium Nanocrystals

Ruthenium （Ru） nanocrystals （NCs） embedded in SiO2 gate stacks are formed by rapid thermal annealing for the whole gate stacks and embedded in the memory structure, which is compatible with conventional CMOS technology. The devices exhibit a substantial and clockwise hysteresis in capacitance-voltage measurement. The Ru NCs exhibit high density （2 × 10^12cm^-2）, small size （2-4 nm） and good uniformity both in spatial distribution and morphology. The charging and long-term retention performances are explained by the Coulomb Blockade phenomena and the asymmetric electron tunnel barrier between the Ru NCs and the Si substrate, respectively.     

一类含萘环结构的聚酯酰亚胺液晶聚合物的结构与性能研究

利用Higashi芳香聚酯直接缩聚法的原理,采用分步投料的方法,以N,N′-1,6-亚己基-双苯偏三酸酰亚胺二酸(IA6)、6-羟基-乙-萘甲酸(HNA)和4,4′-二羟基二苯酮(DHBP)为单体原料,合成了一系列聚酯酰亚胺共聚物.用核磁共振(NMR)、差热分析(DSC)、偏光显微镜(PLM)、广角X射线衍射(WAXD)、热重分析(TGA)等手段对所合成的聚酯酰亚胺的液晶行为、结构以及热性能进行了表征.研究结果表明,当HNA投料量占单体总投料量高于33mol%时,所得聚合物均呈明显的向列型热致液晶特性.但是,此类液晶聚合物仅在升温过程中出现液晶的相转变,而在降温过程中并未观察到液晶的相转变行为.由DSC结果分析可知,此类聚合物具有较高的玻璃化转变温度(Tg)和较低的熔融温度(Tm),有望成为一类既具有较低加工温度又有较高使用温度的液晶聚合物材料.     

Improved interfacial and electrical properties of GaSb metal oxide semiconductor devices passivated with acidic （NH4）2S solution

Surface passivation with acidic(NH4)2S solution is shown to be effective in improving the interfacial and electrical properties of HfO2/GaSb metal oxide semiconductor devices. Compared with control samples, the samples treated with acidic(NH4)2S solution show great improvements in gate leakage current, frequency dispersion, border trap density, and interface trap density. These improvements are attributed to the enhancing passivation of the substrates, according to analysis from the perspective of chemical mechanism, X-ray photoelectron spectroscopy, and high-resolution cross-sectional transmission electron microscopy.     

碱式硫酸镁晶须水热过程结晶动力学研究

采用水热法合成了碱式硫酸镁晶须,利用扫描电镜、透射电镜、X射线能谱仪和X射线衍射仪等对产物的形貌和组成进行表征。通过考察不同温度下SO42-浓度随时间的变化,对碱式硫酸镁晶须的结晶动力学进行了研究。利用MATLAB软件和Runge-Kutta数值解法对实验数据进行处理,得出不同温度下晶须的结晶动力学方程。对晶须的几种生长机理模型进行分析发现,低温和高温的动力学模型不同,反应温度为170℃、180℃、190℃时的动力学模型分别为MB-1、MB-2和MB-3,结晶机理为多核控制表面生长,结晶速率由表面反应控制;反应温度为200℃和210℃时,结晶机理发生了变化,为单核控制表面生长,结晶动力学模型分别为MC-2和MC-3。