Ti/莫来石陶瓷界面反应的俄歇电子能谱研究

结果表明，在淀积过程中，最初淀积的Ti与衬底表面的氧形成Ti-O键，界面区很窄；450℃退火1h后，有少量元素态Al、Si原子析出，界面区有所展宽，但变化不大；650℃退火1h后，界面发生强烈反应，有TiO和Ti-Al、Ti-Si化合物生成。850℃退火1h后，除上述反应产物外又生成了Ti_2O。

Ti薄膜与AlN陶瓷的界面反应

用X射线衍射分析、二次离子质谱、卢瑟福背散射谱、俄歇电子能谱等表面分析技术，研究了Ti膜与AlN陶瓷衬底的界面固相反应。在高真空中用电子束蒸发的方法在抛光的200℃AlN陶瓷衬底上淀积200nm的Ti膜，并在真空恒温炉中退火。实验表明，退火中Ti膜与AlN界面发生了扩散与反应。650℃，1h退火已观测到明显的界面反应。界面反应产物主要是钛铝化物及Ti-N化合物。铝化物是Ti-Al二元化合物和Ti-Al-N三元化合物，850℃,4h退火后则主要由Ti_2AlN组成。

Ti和AlN陶瓷的界面反应

采用电子束蒸发的方法在抛光的200℃AlN陶瓷衬底上淀积厚度为200nm的Ti膜，并在高真空中退火。研究了从200￣850℃温区内Ti与AlN的固相界面反应，给出了界面组分分布随退火温度和时间的变化关系。在界面区发生了三元铝化物并观测到铝化物产生与发展过程。

Ti和蓝宝石的界面反应

在超高真空中用电子束蒸发在抛光的(1102)取向的蓝宝石(a-Al_2O_3)衬底上蒸镀500 nm的Ti膜,在恒温炉中退火,然后用XRD(包括一般的和小角度的X射线衍射),AES和SIMS等表面分析技术详细研究了从室温至850℃,Ti与a-Al_2O_3的固相界面反应.首次系统提出了不同反应温区相应的化学反应式,讨论了采用体材料数据作热力学计算来预言Ti/a-Al_2O_3界面反应的局限性.

Optical properties of AIInGaN quaternary alloys

Carrier recombination dynamics in AlInGaN alloy has been studied by photoluminescence (PL) and time-resolved photoluminescence (TRPL). The fast redshift of PL peak energy is observed and well fitted by a physical model considering the thermal activation and transfer processes. This result provides evidence for the exciton localization in the quantum dot (QD)-like potentials in our AlInGaN alloy. The TRPL signals are found to be described by a stretched exponential function of exp[(-t/tau)(beta)], indicating the presence of a significant disorder in the material. The disorder is attributed to a randomly distributed quantum dots or clusters caused by indium fluctuations. By studying the dependence of the dispersive exponent 8 on the temperature and emission energy, we suggest that the exciton hopping dominate the diffusion of carriers localized in the disordered quantum dots. Furthermore, the localized states are found to have OD density of states up to 250 K, since the radiative lifetime remains almost unchanged with increasing temperature.

Ti Schottky barrier diodes on n-type 6H-SiC

Using thermal evaporation, Ti/6H-SiC Schottky barrier diodes (SBD) were fabricated. They showed good rectification characteristics from room temperature to 200degreesC. At low current density. the current conduction mechanism follows the thermionic emission theory. These diodes demonstrated a low reverse leakage current of below 1 X 10(-4)Acm(-2). Using neon implantation to form the edge termination, the breakdown voltage was improved to be 800V. In addition. these SBDs showed superior switching characteristics.

The SPER and characteristics of Si1-yCy alloys

\Si1-yCy alloys with carbon composition of 0.5 at.% were successfully grown on n-Si(100) substrate by solid phase epitaxy recraystallization. The result was presented in this paper. With the help of the SiO2 capping layer, rather uniform carbon profile in amorphous Si layer was obtained by dual-energy implantation. Since ion-flow was small and implantation time was long enough, the emergency of beta-SiC was avoided and the dynamic annealing effect was depressed. The pre-amorphization of the Si substrate increased the fraction of the substitutions carbon and the two-step annealing reduced point defects. As a result, Si1-yCy alloys with high quality was recrystallized on Si substrate.

Pressure behavior of deep centers in ZnSxTe1-x alloys

We have measured photoluminescence of ZnSxTe1-x alloys (x > 0.7) at 300 K and under hydrostatic pressure up to 7 GPa. The spectra contain only a broad emission band under excitation of the 406.7 nm line. Its pressure coefficients are 47, 62 and 45 meV/GPa for x = 0.98, 0.92 and 0.79 samples, which are about 26%, 7% and 38% smaller than that of the band gap in the corresponding alloys. The Stokes shifts between emission and absorption of the bands were calculated by fitting the pressure dependence of the emission intensity, being 0.29, 0.48 and 0.13 eV for the three samples, respectively. The small pressure coefficient and large Stokes shift indicate that the emission band observed in our samples may correspond to the Te isoelectronic center in the ZnSxTe1-x alloy.

TI C28X系列MCU电源管理设计TI C28X系列MCU电源管理设计

A brief summary of TI C28X MCU is presented in this paper. The key points of power management design for all C28X MCU based on different requirements on power management are proposed. Two different solutions of power management design with specific examples can help C28X MCU developers with technical advice and have positive impact on application of C28X MCU in the field of industrial control.中文摘要：本文对 TI C28X 系列 MCU 作了简要归纳和介绍 针对各款 MCU 对电源管理的不同要求,提出了全系列 MCU 的电源管理部分设计要点,总结了两类不同的电源管理设计方案,对每类方案均给出了具体的设计案例 为 C28X 系列 MCU 的电源管理设计提供了技术指导,对促进 C28X 系列 MCU 在工业控制领域内的应用有积极的意义.

TI TMS320C6713 DSP板Flash二级装载程序设计

DSP系统的程序都是保存在非易失性存储器中,系统启动的时候,程序加载到系统的RAM中去执行。本文详细描述了TITMS320C6713DSP板以Flash作为引导存储器,采用二级装载的办法来实现程序的加载,并给出了数据传输的代码片断。文章介绍的这种二级装载的方法也可以应用于C6000系列其他型号的处理器。