共查询到20条相似文献,搜索用时 31 毫秒
1.
硅发光对于在单一硅片上实现光电集成是至关重要的.目前已有的使硅产生发光的方法有:掺杂深能级杂质、掺稀土离子、多孔硅、纳米硅以及Si/SiO2超晶格.声空化所引发的特殊的物理、化学环境为制备光致发光多孔硅薄膜提供了一条重要的途径.实验表明,声化学处理对于改善多孔硅的微结构,提高发光效率和发光稳定性都是一项非常有效的技术.超声波加强阳极电化学腐蚀制备发光多孔硅薄膜,比目前通用的常规方法制备的样品显示出更优良的性质.这种超声波的化学效应源于声空化,即腐蚀液中气泡的形成、生长和急剧崩溃.在多孔硅的腐蚀过程中,由于超声波的作用增加了孔中氢气泡的逸出比率和塌缩,有利于孔沿垂直方向的腐蚀,使多孔硅光致发光峰的半峰全宽压缩到了3.8nm. 相似文献
2.
The study of the solution concentration influencing on laser-induced electrochemical etching silicon
The laser electrochemical etching process, which combines the laser direct etching process and the electrochemical etching process, is a compound etching technique. In order to further understand the solution concentration influencing on the laser-induced electrochemical etching of silicon; a 248 nm excimer laser as a light source and KOH solution as an electrolyte were adopted in this study. The experiments of micromachining silicon by laser-induced electrochemical etching were carried out. On the basis of the experiments results, the solution concentration influencing on the etching rates in the process of laser electrochemical etching of silicon was researched. The reasons of the etching phenomena were analyzed in detail. The experimental results indicate that the solution concentration influencing on the etching process is mainly rooted in the absorption of different concentration solutions to laser. In general, less absorption and low solution concentration are good for the etching role in the process of laser electrochemical etching. 相似文献
3.
Neeraj Kumar Salvatore Gennaro Pradeep Vallachira Warriam Sasikumar Gian Domenico Sorarù Paolo Bettotti 《Applied Physics A: Materials Science & Processing》2014,116(1):251-257
In this article we describe a reliable etching method to fabricate porous silicon free-standing membranes (FSMs) based on a self detachment of the porous layer in moderately doped n-type silicon substrates. We found that stable growth of smooth and straight pores is restricted to a narrow range of etching conditions and, unlike p-type substrates, the lift-off of the membrane is a self-limited process that does not require a large burst of current. The detachment of the porous membrane is independent of the structure of the already porosified layer, meaning that the average pore diameter can be tuned from nano to macro size within the same membrane. We also demonstrate that, despite their limited thickness, FSMs are quite robust and can sustained further processing. Thus, the etching receipt we are proposing here extends the range of sensors and filters that can be fabricated using porous silicon technology. 相似文献
4.
Y. LiuZ.H. Xiong Y. LiuS.H. Xu X.B. LiuX.M. Ding X.Y. Hou 《Solid State Communications》2003,127(8):583-588
Ultrasonically enhanced anodic electrochemical etching is developed to fabricate luminescent porous silicon (PS) material. The samples prepared by the new etching method exhibit superior characteristics to those prepared by conventional direct current etching. By applying ultrasonically enhanced etching, PS microcavities with much higher quality factors can be fabricated. The improved quality induced by ultrasonic etching can be ascribed to increased rates of escape of hydrogen bubbles and other etched chemical species from the porous silicon pillars' surface. This process will cause the reaction between the etchant and the silicon wafer to proceed more rapidly along the vertical direction in the silicon pores than laterally. 相似文献
5.
The influence of electron irradiation on the light-emitting properties of p-and n-type porous silicon prepared by electrochemical etching is investigated. The dose and energy dependences of the electron-stimulated
quenching of the photoluminescence (PL) are determined. It is shown that electron treatment of a porous silicon surface followed
by prolonged storage in air can be used to stabilize the PL. The excitation of photoluminescence by a UV laser acting on sections
of porous silicon samples subjected to preliminary electron treatment is discovered for the first time. The influence of the
electron energy and the power of the laser beam on this process is investigated. The results presented are attributed to variation
in the number of radiative recombination centers as a result of the dissociation and restoration of hydrogen-containing groups
on the pore surface.
Zh. Tekh. Fiz. 68, 58–63 (March 1998) 相似文献
6.
7.
This review is devoted to the analysis of the problems related to fabrication of the Si porous layers. The review was motivated by a great interest to Si-based porous materials from nano- to macro-scale for various applications in electronics, optoelectronics, photonics, chemical sensors, biosensors, etc. The peculiarities of the silicon porosification and the principles of preparing porous layers are considered in the present article. Various methods used for Si porosification such as chemical stain etching, chemical vapor etching, laser-induced etching, metal-assisted etching, spark processing and reactive ion (plasma) etching were analyzed. However, the main attention was focused on electrochemical porosification of Si. The review discusses in detail the influence of parameters such as electrolyte composition and pH, current density, etching time, temperature, wafer doping and orientation, lighting, magnetic field, and ultrasonic agitation on the process of Si porosification. It was shown that the structure of porous silicon strongly depends on both technological parameters of electrochemical etching and the parameters of the semiconductor subject to treatment. This review also addresses the main properties of porous silicon, porous multilayer and 3D structure formation, oxidation of porous Si, release of the porous layer, drying, storage, etching, filling and surface functionalizing of porous Si. Features of III-V compound porosification are also briefly analyzed. 相似文献
8.
声空化所引发的特殊的物理、化学环境为制备高效发光的多孔硅薄膜提供了一条重要的途径.实验结果表明,声化学处理对于改善多孔硅的微结构,提高发光效率和发光稳定性都是一项非常有效的技术.超声波加强阳极电化学腐蚀制备发光多孔硅薄膜,比目前通用的常规方法制备的样品显示出更优良的性质.这种超声的化学效应源于声空化,即腐蚀液中气泡的形成、生长和急剧崩溃,在多孔硅的腐蚀过程中,孔中的氢气泡,由于超声波的作用增加了逸出比率和塌缩,有利于孔沿垂直方向的腐蚀.
关键词:
声空化方法
微结构
发光特性
多孔硅 相似文献
9.
Zhengtao Qin Jinmyoung Joo Luo Gu Michael J. Sailor 《Particle & Particle Systems Characterization》2014,31(2):252-256
Size‐controlled porous silicon‐based nanoparticles are prepared by pulsed electrochemical etching of single crystal silicon wafers, followed by ultrasonic fracture of the freestanding porous layer. When high‐current density pulses are applied periodically during the porous layer etching process, a porous multilayer results in which porous layers are separated by thin layers of much higher porosity. Ultrasonic fracture selectively cleaves the porous film along these high‐porosity perforations, providing greater size control and improved yields (by 5x) of the resulting porous nanoparticles. The effect of pulse width and repetition rate is systematically studied: tunability of the average nanoparticle size in the range 160–350 nm is demonstrated. 相似文献
10.
《Current Applied Physics》2010,10(3):930-933
In this paper, we studied the PL property and the surface morphology of porous silicon prepared from N-type single silicon wafers coated with and without Al film. By introducing the Al film on the surface of silicon wafer before etching, the morphology of porous silicon exhibits obvious discrimination compared with that of the conventional porous silicon, which can be explained by the formation mechanism of the samples, and the emission property of two-type porous silicon also showed the clear difference, which may be attributed to the discrepancy in the structural configuration of the samples. Furthermore, it was found that the blue emission decreased and the green emission was almost completely quenched after boron-particle deposition, which is attributed to the structural change or annihilation of the emission defects during annealing process. 相似文献
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12.
Kurt W. Kolasinski 《Surface science》2009,603(10-12):1904-1911
The development and status of what is commonly called the Gerischer mechanism of silicon etching in fluoride solutions is reviewed. The two most widely used and studied wet etchants of silicon are F? and OH?. Their mechanisms of atom removal share many things in common; in particular, chemical passivation by a hydrogen-terminated surface plays an important role in both. Crucially, however, their initiation steps are different, and this leads to important differences in the structures of the materials produced by the etchants. The initiation of etching by F? is electrochemical in nature, responding to the electronic structure of the Si, and is, therefore, a self-limiting reaction that can produce nanocrystalline porous silicon. Hydroxide etching destroys porous silicon because its initiation step is a catalytic chemical reaction and not a self-limiting process. A number of unanswered questions regarding the dynamics of fluoride etching are highlighted. 相似文献
13.
S. De La Luz Merino F. Morales-Morales A. Méndez-Blas M. E. Calixto F. G. Nieto-Caballero G. García-Salgado 《Applied Physics A: Materials Science & Processing》2013,111(4):1077-1083
In this work, we report the experimental results on the formation of porous silicon (PSi) monolayers by electrochemical etching using a formaldehyde based electrolyte. The results were compared with PSi monolayers obtained with the traditional electrolyte (HF:ethanol). Both electrolytes facilitate the removal of H2 generated as a subproduct during the electrochemical etching process in the surface of the c-Si substrate. Formaldehyde presents a good affinity to surfaces and interfaces and the excess of water in the electrolyte reduces the pore sizes of PSi samples. The porosity and etching rate values are similar than those obtained using HF:et solutions. The refractive index values are the same in both cases at the same porosity in the visible range. The results have shown that the chemical characteristics of the ethanol and formaldehyde can give some different advantages to the PSi process and its applications. 相似文献
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15.
Masato Ohmukai Nobutomo Uehara Tetsuya Yamasaki Yasuo Tsutsumi 《Czechoslovak Journal of Physics》2004,54(7):781-784
We have investigated the effects of chemical etching on Raman spectra of porous silicon. The as-anodized porous silicon consisted
mainly of crystalline silicon, as indicated by the Raman spectra. The background in the spectrum was strong, indicating that
the porous silicon surface was rough due to the presence of pores. When chemical etching was performed five times, the Raman
spectrum revealed the presence of spherically shaped nanocrystalline silicon whose diameter was around 3.5 nm. Further chemical
etching, however, extinguished the nanocrystallites, in addition to smoothing the surface morphology. 相似文献
16.
Nanosecond pulsed laser ablation of silicon in liquids 总被引:2,自引:0,他引:2
R. Karimzadeh J. Zamir Anvari N. Mansour 《Applied Physics A: Materials Science & Processing》2009,94(4):949-955
Laser fluence and laser shot number are important parameters for pulse laser based micromachining of silicon in liquids. This
paper presents laser-induced ablation of silicon in liquids of the dimethyl sulfoxide (DMSO) and the water at different applied
laser fluence levels and laser shot numbers. The experimental results are conducted using 15 ns pulsed laser irradiation at
532 nm. The silicon surface morphology of the irradiated spots has an appearance as one can see in porous formation. The surface
morphology exhibits a large number of cavities which indicates as bubble nucleation sites. The observed surface morphology
shows that the explosive melt expulsion could be a dominant process for the laser ablation of silicon in liquids using nanosecond
pulsed laser irradiation at 532 nm. Silicon surface’s ablated diameter growth was measured at different applied laser fluences
and shot numbers in both liquid interfaces. A theoretical analysis suggested investigating silicon surface etching in liquid
by intense multiple nanosecond laser pulses. It has been assumed that the nanosecond pulsed laser-induced silicon surface
modification is due to the process of explosive melt expulsion under the action of the confined plasma-induced pressure or
shock wave trapped between the silicon target and the overlying liquid. This analysis allows us to determine the effective
lateral interaction zone of ablated solid target related to nanosecond pulsed laser illumination. The theoretical analysis
is found in excellent agreement with the experimental measurements of silicon ablated diameter growth in the DMSO and the
water interfaces. Multiple-shot laser ablation threshold of silicon is determined. Pulsed energy accumulation model is used
to obtain the single-shot ablation threshold of silicon. The smaller ablation threshold value is found in the DMSO, and the
incubation effect is also found to be absent. 相似文献
17.
Modeling of the optical properties of porous silicon photonic crystals in the visible spectral range
D. S. Dovzhenko I. L. Martynov I. S. Kryukova A. A. Chistyakov I. R. Nabiev 《Optics and Spectroscopy》2017,122(1):79-82
Optical devices based on photonic crystals are of great interest because they can be efficiently used in laser physics and biosensing. Photonic crystals allow one to control the propagation of electromagnetic waves and to change the emission characteristics of luminophores embedded into photonic structures. One of the most interesting materials for developing one-dimensional photonic crystals is porous silicon. However, an important problem in application of this material is the control of the refractive index of layers by changing their porosity, as well as the refractive index dispersion. In addition, it is important to have the possibility of modeling the optical properties of structures to choose precisely select the fabrication parameters and produce one-dimensional photonic crystals with prescribed properties. In order to solve these problems, we used a mathematical model based on the transfer matrix method, using the Bruggeman model, and on the dispersion of silicon refractive index. We fabricated microcavities by electrochemical etching of silicon, with parameters determined by the proposed model, and measured their reflection spectra. The calculated results showed good agreement with experimental data. The model proposed allowed us to achieve a microcavity Q-factor of 160 in the visible region. 相似文献
18.
Z. G. Sun H.Akinaga 《光散射学报》2005,17(3):214-215
pacc:7855C Theusageofhydrofluoricacid(HF)orfluo ridewasbelievedtobeindispensableinthefabri cationofporoussilicon(PSi)sinceitsdiscovery. Herewereportanovelmethod,metal-assisted -chemical-reaction-etching(MACRE) method,topreparePSiwithoutHFacidorfluo rid… 相似文献
19.
In this paper, we present a study on the porous silicon surface with the aim of filling porous silicon layers with organics. We discuss on two processes used to remove the outer parasitic layer created during the porous silicon formation. We demonstrate that these etching processes influences the surface properties, in particular wetting ability. By XPS and infrared absorption spectroscopy studies, we show that a SF6 plasma treatment does not modify irreversibly the chemistry of porous silicon surface, nor the surface morphology. We also point out that NaOH etching does bring significant morphological modifications and influences the hydrophilicity of the porous silicon surface. This last treatment increases the polar groups (SiO) concentration on the pore surface and therefore allows a better filling of a porous silicon layer with organics, like dibromo-EDOT which can be thermally converted into PEDOT. 相似文献
20.
A series of porous silicon samples prepared at different etching parameters, namely etchant composition, etching time and current density, was investigated as substrates for surface-enhanced Raman scattering (SERS). Silver nanostructures were deposited on porous silicon by immersion plating method and Rhodamine 6G was used as analyte. The relation between the etching parameters, morphology of porous silicon surface and its SERS efficiency after silver deposition is examined. We show that a high HF content in the etchant allows the formation of a film with close-packed silver nanocrystals, which possess strong surface enhancement properties. 相似文献