Characteristic features of thermoluminescence kinetics in dosimetric aluminum oxide crystals

We have studied the thermoluminescence curves in the 420 nm band (F centers) and the 330 nm band (F⁺ centers) within the temperature range of the dosimetric peak (T_max = 450 K) in anion-deficient aluminum oxide crystals. Assuming general-order kinetics, we have analyzed the thermoluminescence decay curves on the rising and falling sides of the dosimetric peak, in samples with different degrees of deep trap filling. We have established differences in the order of the kinetics within different temperature ranges of the dosimetric peak. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 187–190, March–April, 2006.     

Markov Chains in a Field of Traps

We consider a Markov chain on a countable state space, on which is placed a random field of traps, and ask whether the chain gets trapped almost surely. We show that the quenched problem (when the traps are fixed) is equivalent to the annealed problem (when the traps are updated each unit of time) and give a criterion for almost sure trapping versus positive probability of nontrapping. The hypotheses on the Markov chain are minimal, and in particular, our results encompass the results of den Hollander, Menshikov and Volkov (1995).     

立方体AgCl微晶中[Fe(CN)_6]~(4-)引入的浅电子陷阱阱深与俘获截面的动力学模拟

为了描述在晶体生长阶段掺入 [Fe(CN) 6 ]4 - 的立方体AgCl微晶中光电子的产生与衰减过程 ,建立了一种由三个固有中心和一个浅电子陷阱 (SETs)组成的动力学模型 ,并引出一组微分方程 .通过求解微分方程得到与实验结果相符合的光电子衰减曲线及其寿命 .调整相关模拟参数 ,于常温下得到由 [Fe(CN) 6 ]4 - 引入的SETs阱深为0 115eV ,电子俘获截面为 2 136× 10 - 1 7cm2 .     

Material and electrical characteristics of iron doped Pt-lnAIAs schottky diodes grown by LP-MOCVD

InAlAs lattice-matched to InP is of great importance as a large bandgap material for various InP-based heterostructures device applications. However, growth of good quality InAlAs using metalorganic chemical vapor deposition (MOCVD) is relatively difficult due to the reactive nature of its aluminum sources. In this paper, we present the use of iron as a possible dopant to improve the electrical properties of MOCVD grown InAlAs. Time resolved photoreflectance was used to confirm the increase in trap levels with increased iron doping. The impact of iron doping on the electrical properties of devices was investigated using Pt-Schottky diodes fabricated on undoped and iron doped InAlAs materials. Low frequency noise measurements were also carried out to investigate the impact of iron incorporation on the noise characteristics of the devices. Although noise levels showed marginal difference between undoped and iron doped materials, iron doped InAlAs showed a Lorentzian component in the noise spectra which is not found in undoped materials. An activation energy of ∼0.77 eV was evaluated for traps introduced by iron incorporation using temperature dependent low frequency noise measurements.     

新生界面陷阱对Fowler-Nordheim电压漂移的影响

用陷阱俘获模型和恒流方法研究了新生界面陷阱对薄氧化层MOS电容器的F-M(Fow-ler-Nordheim)电压(V_(FN))的影响,得到了电压漂移量△V_(FN)随时间变化的解析表述式.分析结果表明:(d△V_(FN))/(dt)vs △V_(FN)曲线可以用几段直线描述.采用线性化技术,可以方便地识别多陷阱现象.并分别提取原生陷阱及新生陷阱参数.实验结果表明:在恒流隧道电子注入的初始阶段,F-N电压漂移量主要由新生界面陷阱的电子俘获过程所决定,紧接着是原生氧化层体陷阱的电子俘获,然后是新生氧化层体陷阱的电子俘获.     

Radiation sensitivity of buried oxides

Capacitance-voltage (C-V) techniques have been used to examine the 10-keV x-ray radiation sensitivity of buried oxides that are created by the implantation of oxygen into silicon. Buried oxide to substrate interfaces have been studied by using samples implanted with different oxygen implant doses from a 100 mA-class implanter. Fiatband voltage (Vfb) shift for the buried oxide to the substrate interface has been used to monitor charge buildup as a function of radiation dose and applied electrical bias. The Vfb shift of the buried oxides indicate a oxide trapping behavior that is different than that of thermal oxides.     

Planar ion chip design for scalable quantum information processing

We investigate a planar ion chip design with a two-dimensional array of linear ion traps for scalable quantum information processing. Qubits are formed from the internal electronic states of trapped ^40Ca^＋ ions. The segmented electrodes reside in a single plane on a substrate and a grounded metal plate separately, a combination of appropriate rf and DC potentials is applied to them for stable ion confinement. Every two adjacent electrodes can generate a linear ion trap in and between the electrodes above the chip at a distance dependent on the geometrical scale and other considerations. The potential distributions are calculated by using a static electric field qualitatively. This architecture provides a conceptually simple avenue to achieving the microfabrication and large-scale quantum computation based on the arrays of trapped ions.     

ZnSeTe／ZnSe量子阱中Te等电子陷阱的静压光子发光谱研究

测量了ZnSe0.92Te0.08/ZnSe超晶格量子阱材料在77K时0-7.8GPa静压下的光致发光谱。观察到ZnSe0.92Te0.08阱层中Te等电子陷阱上的束缚洋鬼子发光，发现它的压力系数比ZnSe带边发光的压力系数小的约50%，表明Te等电子陷阱对激子的束缚势是相当局域的。还观察到了激子在ZnSe0.92Te0.08阱层中的Te等电子陷阱能级与相邻（CdSe)1/(ZnSe)3短周期超晶格之间的转移现象。     

外势场中玻色--爱因斯坦凝聚性质的研究

(1)简要介绍BEC概念的一种含义及BEC形成的条件；(2)着重对外势场中的BEC作了研究，得出了低维情况下产生BEC的条件：当U(x)-2^η时，一维情况发生BEC满足η＜2；二维情况发生BEC满足η＞0。     

Static and low-frequency noise characterization in submicron MOSFETs for memories cells applications

In this paper, we present the extraction of oxide traps properties of n-metal-oxide-semiconductor (N-MOS) field effect transistors with W×L=0.5×0.1 μm² using low-frequency (LF and random telegraph signal) noise and static I(V) characterizations. The impact of oxide thickness, on static and noise parameters is analyzed. Static measurements on N-MOS devices with different tunnel oxide thickness show anomalies (a significant increase in V_t values for low temperature and kink effect) attributed to traps located in the oxide. From LF noise analysis we find that 1/f noise stems from carrier number fluctuations. The slow oxide trap concentration deduced from the noise data is about 10¹⁵ eV/cm³ in agreement with the state-of-the-art gate oxides. Finally, drain current RTS amplitude as large as 10% have been observed.