Structure and electronic properties of SiC thin-films deposited by RF magnetron sputtering

SiC thin-films were prepared by RF-magnetron sputtering technique(RMS) with the target of single crystalline SiC and then annealed. The surface morphology of thin-films was characterized by AFM. The result shows that the surface of the thin-films is smooth and compact; XRD analysis reveals that the thin-films are amorphous. The thickness, square-resistance and curves of resistance—temperature were measured. The results show that the curves of lnR versus 1/kT both before and after annealing satisfy the expression of lnR∝△W/kT, where ?W is electron excitation energy in the range of 0.014 2-0.018 5 eV, and it has a trend of increasing when the temperature is increased. After synthetical analysis we get the conclusion that the electronic mechanism of the thin-films is short distance transition between the localized states in the temperature range of 25-250 ℃. The resistivity is in the range of 2.4×10-3-4.4×10-3 Ω·cm and it has the same trend as electron excitation energy when annealing temperature is increased, which further confirms the electronic mechanism of thin-films and the trend of electron excitation energy versus annealing temperature.     

An S/H circuit with parasitics optimized for IF-sampling

An IF-sampling S/H is presented, which adopts a flip-around structure, bottom-plate sampling technique and improved input bootstrapped switches. To achieve high sampling linearity over a wide input frequency range, the floating well technique is utilized to optimize the input switches. Besides, techniques of transistor load linearization and layout improvement are proposed to further reduce and linearize the parasitic capacitance. The S/H circuit has been fabricated in 0.18-μm CMOS process as the front-end of a 14 bit, 250 MS/s pipeline ADC. For 30 MHz input, the measured SFDR/SNDR of the ADC is 94.7 dB/68. 5dB, which can remain over 84.3 dB/65.4 dB for input frequency up to 400 MHz. The ADC presents excellent dynamic performance at high input frequency, which is mainly attributed to the parasitics optimized S/H circuit.     

安防监控运营平台实现方案

为满足安防监控系统的运营需求,助力监控产业的快速发展。本文提出一个适用于运营级安防监控平台的设计方案,从系统组成方案、网络传输及拓扑、存储以及扩展和兼容等方面阐述系统总体方案,并简述系统主要功能组成设计及实现等。     

磁控溅射SiC薄膜及其光电特性研究

用射频磁控溅射法制备了SiC薄膜,并对其进行了退火处理.用AFM观察了薄膜的表面形貌,测量了薄膜的厚度与透射光谱.用J.C.Manifacier提出并由R.Swanepoel加以修正和完善的包络线法对薄膜透射光谱进行了分析计算,并结合Tuac公式确定了薄膜的光学带隙.结果表明:在不同射频功率下制备的薄膜均有较强的蓝紫光吸收特性,在低功率下可制备出表面平整,吸收系数小,光学带隙大的薄膜;退火处理后薄膜的吸收系数减小,光学带隙增大,晶粒向圆形转化且尺寸变大.     

Preparation and properties of SiCN diffusion barrier layer for Cu interconnect in ULSI

SiCN thin films and Cu/SiCN/Si structures were fabricated by magnetron sputtering. And some samples underwent the rapid thermal annealing(RTA) processing. The thin-film surface morphology, crystal structure and electronic properties were characterized by atomic force microscopy(AFM), X-ray diffractometry(XRD), Fourier transform infrared transmission(FTIR) and four-point probe(FPP) analyses. The results reveal the formation of complex networks among the three elements, Si, C and N, and the existence of different chemical bonds in the SiCN films, such as Si-C, Si-N, C-N and C=N. The as-deposited SiCN thin films are amorphous in the Cu/SiCN/Si structures and have good thermal stability, and the SiCN thin films are still able to prevent the diffusion reaction between Cu and Si interface after RTA processing at 600 ℃ for 5 min.     

一种基于65 nm CMOS工艺的3抽头前馈均衡器

高速串行接口技术是当前高速数据传输的关键技术之一,而前馈均衡器(FFE)是高速串行接口中的重要模块电路。设计了一款工作在40 Gb/s、用于高速串口发送端的前馈均衡器;分析了FFE求和模块、延时模块对均衡效果的影响;采用LC网络作为延时单元,并通过设计闭环反馈控制来控制延时时间,解决了高速均衡电路的延时实现问题。电路采用TSMC 65 nm CMOS工艺进行设计和仿真,后仿真结果表明,在40 Gb/s数据传输时,该3抽头FFE电路具有20 dB的均衡能力;在TT_27 ℃工艺角、1.0 V电源电压下,电路功耗为51.52 mW。     

SiC薄膜材料与器件最新研究进展

SiC单晶因其宽的禁带宽度、高的电子饱和速度、大的临界击穿场强、高的热导率和热稳定性等特性而成为制作高频、大功率和耐高温器件的理想材料.综述了SiC材料及器件的研究现状、关键技术和发展趋势;分析了我国的研究现状和存在的差距.     

SiCN扩散阻挡层薄膜的制备及特性研究

采用磁控溅射法在单晶硅衬底上制备了SiCN及Cu/SiCN薄膜,并对试样进行了退火处理.利用原子力显微镜(AFM)、X射线衍射(XRD)、四探针测试仪(FPP)研究了SiCN薄膜的表面形貌、物相结构及在Cu/SiCN/Si结构中SiCN薄膜对铜与硅的阻挡性能.结果表明,沉积态SiCN薄膜为无定型的非晶结构,晶化温度在1000℃以上;SiCN薄膜作为Cu的扩散阻挡层有较好的热稳定性及阻挡性,阻挡失效温度在600℃左右.     

海绵城市设计思考与应用研究

针对现代城市发展过程中受水资源影响严重这一现状进行分析。首先,对海绵城市进行了阐述;其次,介绍了设计海绵城市的方法;最终,详细的分析了城市设计过程中对海绵城市理念的合理应用,希望文中内容对相关工作人员能够有所帮助,同时能够促进我国海绵城市的发展,为人们提供良好的生活环境。     

磁控溅射SiC薄膜及其电学特性研究

用磁控溅射法(RMS)制备了SiC微晶薄膜,并对其进行了退火处理.用AFM观察了薄膜的表面形貌,测量了薄膜的厚度、方块电阻和电阻-温度曲线.结果表明:薄膜表面平整光滑;退火处理前后薄膜样品的lnR随1/kT的变化曲线均满足表达式,电子激活能的变化范围为0.0142 eV～0.0185 eV,且随退火温度的升高而增大;分析确定其导电机理为定域态间近程跳跃电导.退火前后薄膜电阻率的范围为2.4×10-3～4.4×10-Ω·cm,且随退火温度的升高而增大,与电子激活能的变化趋势一致,这进一步验证了本文提出的薄膜导电机理和激活能随退火温度的变化趋势.