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1.
Analysis of free carrier absorption measurement of electronic transport properties of silicon wafers
Sensitivity analysis of electronic transport property measurement of silicon wafers with modulated free carrier absorption
(MFCA) technique and multi-parameter fitting procedure is performed. The sensitivity of the multi-parameter estimate employing
the dependences of the MFCA amplitude and phase on the pump-probe-beam separation measured at several modulation frequencies
covering an appropriate range is theoretically compared with that employing only the dependences of the MFCA amplitude and
phase on the modulation frequency. Simulation results show that the dependences of the MFCA amplitude and phase on the pump-probe
beam separation are more sensitive to the electronic transport properties of silicon wafers than the frequency dependences.
The electronic transport properties of the silicon wafers determined with the two-beam separation dependence are therefore
more accurate than that determined with the frequency dependence. Comparative experiments with a silicon wafer are performed
and the carrier lifetime, the carrier diffusivity, and the front surface recombination velocity are determined simultaneously
and unambiguously with both techniques. 相似文献
2.
推导出用于测量半导体载流子输运特性(载流子寿命、载流子扩散系数和前表面复合速度)的调制自由载流子吸收(modulated free carrier absorption, MFCA)检测技术的三维理论模型,给出了调制自由载流子吸收检测信号与调制频率和抽运-探测光相对距离的关系.定性分析了在不同调制频率时各个载流子输运参数对径向位置扫描曲线(信号与两束光相对距离的关系)的影响,结果表明调制自由载流子吸收检测信号对各个参数的灵敏度随抽运-探测光相对距离的增加而增加.仿真和实验结果表明,通过拟合不同调制频率时调
关键词:
调制自由载流子吸收
载流子输运特性
径向位置扫描 相似文献
3.
4.
光载流子辐射技术已广泛应用于半导体材料性能的表征,本文基于一种包含光子重吸收效应的光载流子辐射理论模型,对单晶硅中光子重吸收效应对光载流子辐射信号的影响进行了详细的理论分析.分析结果表明,光子重吸收效应对光载流子辐射信号的影响主要取决于样品掺杂浓度、过剩载流子浓度和过剩载流子的分布.由于过剩载流子浓度及其分布与材料电子输运特性密切相关,电子输运参数的变化将导致光子重吸收效应的影响随之变化.进一步分析了光子重吸收效应对具有不同电子输运特性的样品的电子输运参数的影响,并提出了减小光子重吸收效应影响的方法. 相似文献
5.
Chan Kok Sheng Wan Md. Zin Wan Yunus Anuar Kassim 《Physica B: Condensed Matter》2008,403(17):2634-2638
In this work, the porous silicon layer was prepared by the electrochemical anodization etching process on n-type and p-type silicon wafers. The formation of the porous layer has been identified by photoluminescence and SEM measurements. The optical absorption, energy gap, carrier transport and thermal properties of n-type and p-type porous silicon layers were investigated by analyzing the experimental data from photoacoustic measurements. The values of thermal diffusivity, energy gap and carrier transport properties have been found to be porosity-dependent. The energy band gap of n-type and p-type porous silicon layers was higher than the energy band gap obtained for silicon substrate (1.11 eV). In the range of porosity (50-76%) of the studies, our results found that the optical band-gap energy of p-type porous silicon (1.80-2.00 eV) was higher than that of the n-type porous silicon layer (1.70-1.86 eV). The thermal diffusivity value of the n-type porous layer was found to be higher than that of the p-type and both were observed to increase linearly with increasing layer porosity. 相似文献
6.
A time-domain modulated free-carrier absorption (MFCA) is developed both experimentally and theoretically to investigate the
photo-carrier dynamics of silicon wafers illuminated by a square-wave-modulated super-band-gap laser beam. An explicit three-dimensional
(3-D) theoretical expression for the temporal behavior of the MFCA signal is obtained by solving a 3-D carrier-diffusion equation
The time-domain MFCA model is used to fit the experimental MFCA signals of p- and n-type Si wafers via a multi-parameter fitting
procedure to determine simultaneously the electronic transport properties, that is, the bulk lifetime, the ambipolor diffusivity,
and the front surface recombination velocity. The uncertainties of the fitted parameter values are estimated. 相似文献
7.
提出了采用双波长自由载流子吸收技术同时测量半导体材料载流子体寿命和前表面复合速率的方法.通过数值模拟,定性分析了不同载流子体寿命和前表面复合速率对信号的影响,同时对测量参数的可接受范围和不确定度进行计算并与传统频率扫描自由载流子吸收方法测量结果进行比较.结果表明:提出的双波长自由载流子吸收方法可明显减小载流子体寿命和前表面复合速率的测量不确定度,提高参数测量精度;表面杂质和缺陷越多的样品,其前表面复合速率测量不确定度越小.进一步分析表明,此现象与不同波长激光抽运产生的过剩载流子浓度分布不同有关. 相似文献
8.
本文针对低少子寿命铸造多晶硅片进行试验, 通过一种将多温度梯度磷扩散吸杂工艺与低温退火工艺结合的新型低温退火吸杂工艺, 去除低少子寿命多晶硅片中影响其电性能的Fe杂质及部分晶体缺陷, 提高低少子寿命多晶硅所生产的太阳电池各项电性能. 通过低温退火磷扩散吸杂工艺与其他磷扩散吸杂工艺的比较, 证明了低温退火吸杂工艺具有更好的磷吸杂和修复晶体缺陷的作用. IV-measurement发现经过低温退火工艺处理后的低少子寿命多晶硅, 制备的太阳电池光电转换效率比其他实验组高0.2%, 表明该工艺能有效地提高低少子寿命多晶硅太阳电池各项电性能参数及电池质量. 本研究结果表明新型低温退火磷吸杂工艺可将低少子寿命硅片应用于大规模太阳电池生产中, 提高铸造多晶硅材料在太阳能领域的利用率, 节约铸造多晶硅的生产成本.
关键词:
低温退火
磷吸杂
低少子寿命多晶硅
太阳电池 相似文献
9.
Sandra Herlufsen Klaus Ramspeck David Hinken Arne Schmidt Jens Müller Karsten Bothe Jan Schmidt Rolf Brendel 《固体物理学:研究快报》2011,5(1):25-27
We present a fast and calibration‐free carrier lifetime imaging technique based on photoluminescence (PL) measurements using an InGaAs camera for the examination of crystalline silicon wafers. The carrier lifetime is determined from the time dependent luminescence emission after optical excitation. A ratio, including four PL images acquired at different times during the modulated excitation, is calculated and found to depend only on the camera integration time and the effective carrier lifetime. Therefore, the carrier lifetime is unambiguously determined by this ratio without knowing any additional wafer parameter. We demonstrate the applicability of the dynamic PL technique to multicrystalline silicon wafers. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
10.
本文研究了光纤通信用1.3μmInGaAsP/InP双异质结发光管的频响特性。结果表明:器件有源区掺杂浓度;有源层厚度;注入电流;光谱特性;P-n结特性等因素,对发光管的频响特性有重要影响。老化前有源区DSD的存在与否对频响无明显关系。 相似文献
11.
R. Hoelzl K.-J. Range L. Fabry 《Applied Physics A: Materials Science & Processing》2002,75(4):525-534
Based on experimental findings we set up calculations of numerical modeling of gettering efficiencies for Cu in various silicon
wafers. Gettering efficiencies for Cu were measured by applying a reproducible spin-on contamination in the 1012 atoms/cm2 range, followed by a thermal treatment to redistribute the metallic impurity. Subsequently, the wafers were analyzed by a
novel wet chemical layer-by-layer etching technique in combination with inductively coupled plasma mass spectrometry. We investigated
p/p+ and n/n+ epitaxial wafers with different doping levels and different substrate-doping species. We have also investigated
gettering efficiencies of phosphorus-diffused p- and n-type wafers. Heavilyboron doped silicon exhibited a gettering efficiency
of ∼100%, while gettering by n+ silicon occurred for doping levels >3×1019 atoms/cm3 only. In another set of experiments we investigated the dependence of the gettering efficiency of p-type wafers with poly-silicon
back sides for different cooling rates and Cu spiking levels. A strong dependence on both parameters was found. Cu gettering
in p/p+ epitaxial wafers was modeled by calculating the increased solubility of Cu in p+ silicon compared to non-doped silicon
taking into account the Fermi-level effect, which stabilizes donors in p+ silicon, and the pairing reaction between Cu and
B. Calculated gettering efficiencies were in very good agreement with experimental results. Gettering in n+ silicon was similarly
modeled in terms of pairing reactions and the Fermi-level effect. But, for n-type silicon, many experimental uncertainties
existed; thus, we applied our expressions to solubility data of Hall and Racette to obtain the unknown parameters. The empirical
calculations were in good agreement even with results on n/n+ wafers. For phosphorus-diffused wafers we had to consider an
excess vacancy concentration of 1.2–5.5 times the equilibrium concentration to explain the experimental findings by the model.
Gettering by poly-silicon back sides was simulated by solving the time-dependent diffusion equation with boundary conditions
that take into account different surface reaction rates of silicon point defects. Using this advanced model, the experimentally
measured gettering efficiencies were reproduced within the uncertainty of the measurement.
Received: 3 September 2001 / Accepted: 4 September 2001 / Published online: 20 December 2001 相似文献
12.
Photocarrier radiometry (PCR) was used to characterize four n-type silicon wafers with different resistivity values in the 1-20 Ω cm range. Simulations of the PCR signal have been performed to study the influence of the recombination lifetime and front surface recombination velocity on them; besides, the transport parameters (carrier recombination lifetime, diffusion coefficient, and frontal surface recombination) of the wafers were obtained by means of a fitting procedure. The PCR images that are related to the lifetime are presented, and the first photoelectronic images of a porous silicon sample are obtained. 相似文献
13.
This paper focuses on the applicability of the temporal (TPS) and spatial carrier (SCPS) phase-shifting techniques to the time-average interferogram intensity modulation distribution determination. Both techniques use the same mathematical formulae, but in different domains: temporal and spatial ones. They are sensitive to different types of errors. The influence of main experimental errors: phase-step miscalibration, spatial carrier miscalibration, average intensity changes and intensity noise in both the presented techniques on the fringe function determination (|J0| or J02 in case of sinusoidal vibrations), is discussed. The techniques are compared to find the most appropriate one. The time-average technique with heterodyning for small vibration–amplitude measurements is also discussed. The application of the SCPS method to this technique is shown for the first time. 相似文献
14.
Iron contamination in silicon technology 总被引:3,自引:0,他引:3
A.A. Istratov H. Hieslmair E.R. Weber 《Applied Physics A: Materials Science & Processing》2000,70(5):489-534
This article continues the review of fundamental physical properties of iron and its complexes in silicon (Appl. Phys. A 69, 13 (1999)), and is focused on ongoing applied research of iron in silicon technology. The first section of this article
presents an analysis of the effect of iron on devices, including integrated circuits, power devices, and solar cells. Then,
sources of unintentional iron contamination and reaction paths of iron during device manufacturing are discussed. Experimental
techniques to measure trace contamination levels of iron in silicon, such as minority carrier lifetime techniques (SPV, μ-PCD,
and ELYMAT), deep-level transient spectroscopy (DLTS), total X-ray fluorescence (TXRF) and vapor-phase decomposition TXRF
(VPD-TXRF), atomic absorption spectroscopy (AAS), mass spectrometry and its modifications (SIMS, SNMS, ICP-MS), and neutron
activation analysis (NAA) are reviewed in the second section of the article. Prospective analytical tools, such as heavy-ion
backscattering spectroscopy (HIBS) and synchrotron-based X-ray microprobe techniques (XPS, XANES, XRF) are briefly discussed.
The third section includes a discussion of the present achievements and challenges of the electrochemistry and physics of
cleaning of silicon wafers, with an emphasis on removal of iron contamination from the wafers. Finally, the techniques for
gettering of iron are presented.
Received: 16 November 1999 / Accepted: 7 January 2000 / Published online: 5 April 2000 相似文献
15.
M. V. Mezhennyi M. G. Mil’vidskii V. F. Pavlov V. Ya. Reznik 《Physics of the Solid State》2002,44(7):1284-1290
The specific features in the generation and motion of dislocations in silicon single-crystal wafers after different heat treatments are investigated by the four-point bending technique. It is demonstrated that annealing of silicon single-crystal wafers at a temperature of 450°C leads to their substantial hardening as compared to the postgrowth state. The oxygen-containing precipitates and precipitate dislocation pileups formed in the silicon wafer bulk during multistage heat treatment are efficient heterogeneous nucleation sites of dislocations under the action of thermal or mechanical stresses. It is found that the multistage heat treatment of the silicon wafers under conditions providing the formation of an internal getter within their bulk results in considerable disordering of the wafer structure. The inference is made that the formation of the defect state in the crystal lattice of silicon and the strength characteristics of silicon wafers substantially depend on the temperature-time schedules of the low-temperature stage of multistage heat treatment. 相似文献
16.
Improvement of total-dose irradiation hardness of silicon-on-insulator materials by modifying the buried oxide layer with ion implantation 下载免费PDF全文
The hardening of the buried oxide (BOX) layer of separation by implanted
oxygen (SIMOX) silicon-on-insulator (SOI) wafers against total-dose irradiation
was investigated by implanting ions into the BOX layers. The tolerance to
total-dose irradiation of the BOX layers was characterized by the
comparison of the transfer
characteristics of SOI NMOS transistors before and after irradiation to
a total dose of 2.7
Mrad(SiO2. The experimental results show that the implantation of
silicon ions into the BOX layer can improve the tolerance of the BOX layers
to total-dose irradiation. The investigation of the mechanism of the
improvement suggests that the deep electron traps introduced by silicon
implantation play an important role in the remarkable improvement in
radiation hardness of SIMOX SOI wafers. 相似文献
17.
自从Canham观察到多孔硅(PS)的可见光致发光后,由于其可望成为可与Ⅲ—Ⅴ族半导体材料相媲美的新型光电子材料而引起了科学界极大的兴趣.目前,制备多孔硅一般都采用电化学腐蚀方法. 相似文献
18.
以太阳电池级直拉单晶硅片为材料,利用瞬态微波反射光电导衰减仪研究了硅片分别经过单、双面扩散后Fe-B对与少子寿命τ、陷阱浓度及制备成电池的内量子效率(IQE)的相关性.对于单面扩散后的样品,Fe-B对浓度分布在较大程度上决定了少子寿命分布;对于双面扩散后的样品,Fe-B对浓度显著降低(在135×1011 cm-3左右),已不及其他杂质和缺陷对少子寿命的影响.结合瞬态微波衰减信号和陷阱模型,对单、双面吸杂前后硅片的陷阱浓度进行数值计算,发现经过扩散
关键词:
少子寿命
陷阱浓度
内量子效率
Fe-B对 相似文献
19.
This work investigates the photo-thermal treatment of solar grade (SG) silicon to reduce impurities to a low level suitable for high efficiency low-cost solar cells application. It describes experiment carried out by using a tungsten lamps furnace (rapid thermal processing, RTP) to purify solar grade silicon wafers using a combination of porous silicon (PS) and silicon tetrachloride. This process enables to attract the impurities towards the porous layer where they react with SiCl4 to form metallic chlorides. The gettering effect was studied using the Hall Effect and the Van Der Pauw methods to measure the resistivity, the majority carrier concentration and mobility. We have obtained a significant improvement of the majority carrier mobility after such thermo-chemical treatment. The gettering efficiency is also evaluated by the relative increase of the minority carrier diffusion length L, measured by the light beam induced current (LBIC) technique. 相似文献
20.
飞秒激光辐照下单晶硅薄膜中超快能量输运的数值模拟 总被引:1,自引:1,他引:0
利用载流子输运模型对飞秒激光辐照下单晶硅亚微米薄膜中的能量输运过程进行数值模拟。研究了不同辐照能量密度和不同激光波长对载流子密度和温度超快变化过程的影响规律。结果表明,在800nm激光辐照下,不同入射能量密度仅影响载流子密度和温度响应的峰值,但达到峰值的时刻不变。平衡态的恢复过程受入射能量密度影响很小。在不同波长激光辐照下,光子能量越大,载流子密度和温度达到峰值所用时间越短,对应峰值越大,但衰减速度也越快。当入射光子能量大于单晶硅的直接带隙时,快速衰减时间常数可以与载流子能量弛豫时间相当。 相似文献