Modeling the effect of deep traps on the capacitance–voltage characteristics of p-type Si-doped GaAs Schottky diodes grown on high index GaAs substrates

Numerical simulation, using SILVACO-TCAD, is carried out to explain experimentally observed effects of different types of deep levels on the capacitance–voltage characteristics of p-type Si-doped GaAs Schottky diodes grown on high index GaAs substrates. Two diodes were grown on (311)A and (211)A oriented GaAs substrates using Molecular Beam Epitaxy (MBE). Although, deep levels were observed in both structures, the measured capacitance–voltage characteristics show a negative differential capacitance (NDC) for the (311)A diodes, while the (211)A devices display a usual behaviour. The NDC is related to the nature and spatial distribution of the deep levels, which are characterized by the Deep Level Transient Spectroscopy (DLTS) technique. In the (311)A structure only majority deep levels (hole traps) were observed while both majority and minority deep levels were present in the (211)A diodes. The simulation, which calculates the capacitance–voltage characteristics in the absence and presence of different types of deep levels, agrees well with the experimentally observed behaviour.     

一种高性能的新结构IGBT

提出了一种低功率损耗的新结构IGBT.该新结构的创新点在于其复合耐压层结构,该耐压层包括深扩散形成的n型缓冲层和硼注入形成的透明背发射区两部分.虽然在正常工作条件下,该新结构IGBT工作于穿通状态,但器件仍具有非穿通IGBT(NPT-IGBT)的优良特性.该新结构IGBT具有比NPT-IGBT更薄的芯片厚度,从而可以获得更好的通态压降和关断功耗之间的折衷.实验结果表明:与NPT-IGBT相比较,新结构IGBT的功率损耗降低了40%.     

Al-pillared clays supported rare earths and palladium catalysts for deep oxidation of low concentration of benzene

Al-pillared clays supported rare earths (RE/Al-PILC) are prepared and used as supports of palladium catalysts for deep oxidation of low concentrations of benzene (130-160 ppm). The supports and catalysts are characterized by X-ray powder diffraction (XRD), FT-IR, BET, transmission electron microscopy (TEM) and temperature-programmed reduction (H₂-TPR). The results show that Al-pillaring results in a strong increase in the basal spacing (d_0 0 1) from about 1.2 to 1.8 nm, and an increase in the BET surface area from 63.6 (±3.2) to 238.8 (±11.9) m²/g. Activity tests of deep oxidation of low concentration benzene show catalysts supported on Al-PILC and RE/Al-PILC are obviously more active than that on raw clay. Pd/6% Ce/Al-PILC, in particular, can catalyze the complete oxidation of low concentration benzene at a temperature as low as about 290 °C.     

光刻胶灰化工艺与深亚微米线条的制作

随着器件尺寸的缩小，细线条的制作成为很关键的工艺，普通光学光刻已接近其分辨率的极限，而电子束光刻和Ｘ射线光刻技术复杂、费用昂贵。本文对光刻胶灰化工艺进行了分析和研究，并应用此工艺进行了深亚微米线条的制作，在普通光学光刻机上制作出宽度小于０．２５μｍ细线条。我们已将此工艺成功地应用在深亚微米ＭＯＳＦＥＴ的制作中。     

InAs/GaAs自组织量子点的DLTS谱

将DLTS用于对InAs/GaAsQD结构样品的测量,测定了QD能级发射载流子的热激活能;获得了QD能级俘获电子过程伴随有多声子发射(MPE)、QD能级存在一定程度的展宽、以及在某些特定的生长条件下,存在亚稳生长构形的实验证据.结果表明:DLTS在QD体系的研究中有其特有的功能     

涂胶设备背面冲洗功能的开发与研制

本文根据涂胶设备在加工制品过程中所遇到的制品背面沾污问题，提出改进措施，并根据设备的具体情况，增加了涂胶设备的背面冲洗功能。使制品在涂胶过程中，及时地对制品背面进行冲洗，从而保证了制品背面的洁净度，对提高产品质量和提高产品的成品率有非常重要的意义，同时对开发一些技术要求较高的新品也有深远的影响。     

19F+27Al深部非弹性碰撞产物的角分布

完成了19F+27Al深部非弹性碰撞产物的角分布测量.初步分析了反应产B,C,N,O,F,Ne,Na,Mg和Al的实验室系角分布,展现出深部非弹性反应机制的特点,显示了反应系统随时间的演化过程. Angular distributions of fragments produced in the deep inelastic collision of~(19)F+~(27)Al have been measured for incident energy of 114 MeV at θ_(lab)= 9~(o), 24~(o), 40~(o), 55~(o), 70~(o) and 85~(o). Angular distributions of dissipative products B, C, N, O, F, Ne, Na, Mg and Al are analyzed to provide an evolution process of the intermediate dinuclear system formed in the reaction.     

高厚径比盲孔电镀

盲孔能够大大的增加板的密度,从而减小板面积。介绍了有关高厚径比盲孔电镀的有关工艺,从激光钻孔、金属化孔和电镀几个方面对孔径4mil以上的盲孔电镀进行了研究。     

DX centers in AlxGa1-xAs bulk alloy,AlAs/GaAs ordered,and disordered superlattices

Properties of theDX centers in Al_0.5Ga_0.5As bulk alloy (b-AL), (AlAs)₂ (GaSa)₂ ordered superlattice (o-SL) and (AlAs) _m (GaAs) _n disordered superlattice (d-SL) (m = 1, 2, 3,n = 1, 2, 3) with the same macroscopic composition were measured and compared. By deconvolution of deep level transient spectroscopy (DLTS) spectrum due to theDX center, we have found a decrease in the number of separate peaks in DLTS spectrum in an intentionally atomic ordered arrangement. Visiting Scholar of the Japan Society for the Promotion of Science. On leave from Department of Electrical Engineering, San Jose State University, San Jose, California 95192-0084, USA.     

Accurate measurement of capture cross sections in deep level transient spectroscopy: Application to EL2 in GaAs

A rigorous formulation of capacitance changes during trap filling processes is presented and used to accurately determine the electron capture cross section of EL2 in GaAs at a particular temperature, 377K, in this case. The value, σ_n (377K) = 2.7 × 10⁻¹⁶ cm², is compared with that predicted from the emission dependence.