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基于太赫兹等离激元的半导体表面生化薄膜光谱检测(英文) 被引量:2
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作者 杨涛 辛菊盛 +3 位作者 朱永元 秦亦强 李兴鳌 黄维 《红外与毫米波学报》 SCIE EI CAS CSCD 北大核心 2016年第6期667-671,共5页
提出了一种利用太赫兹表面等离激元对放置在半导体表面的生化薄膜进行光谱测量的新方法.从理论上证明了半导体材料对其传输的太赫兹表面等离子体波具有较强的表面束缚性,从而提高太赫兹波与半导体表面生化薄膜之间的相互作用.通过采用... 提出了一种利用太赫兹表面等离激元对放置在半导体表面的生化薄膜进行光谱测量的新方法.从理论上证明了半导体材料对其传输的太赫兹表面等离子体波具有较强的表面束缚性,从而提高太赫兹波与半导体表面生化薄膜之间的相互作用.通过采用太赫兹时域光谱测量系统,从实验上分别得到了洋葱表皮的太赫兹表面等离子体波和自由空间太赫兹波透射波谱.实验结果表明,当测量对象是厚度仅为自由空间太赫兹波波长约1%的单层洋葱表皮时,表面等离子体波的透射波谱与自由空间太赫兹波透射波谱相比具有更加多的特征吸收峰. 展开更多
关键词 生化薄膜 太赫兹波 等离激元 光谱
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Deposition of Thick SiO_2 from Tetraethylorthosilicate and H_2O by Plasma-Enhanced CVD 被引量:1
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作者 雷红兵 王红杰 +5 位作者 邓晓清 杨沁清 胡雄伟 王启明 廖左升 杨基南 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2001年第5期543-547,共5页
The deposition of silicon dioxide by plasma enhanced chemical vapor deposition from tetraethylorthosilicate (TEOS) and H_2O has been studied.Silicon oxide with refractive index of 1453 has been obtained.Tests on the 5... The deposition of silicon dioxide by plasma enhanced chemical vapor deposition from tetraethylorthosilicate (TEOS) and H_2O has been studied.Silicon oxide with refractive index of 1453 has been obtained.Tests on the 51mm wafers show that both thickness uniformity of ±15% and constant refractive index of 1453 can be achieved.By raising the deposition temperature,the qualities have been improved,while the deposition rate decreased.A SiO_2 thick film deposition technique has been developed combining TEOS-PECVD technique with high temperature annealing. 展开更多
关键词 silicon dioxide plasma-enhanced CVD planar waveguide
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Growth and Optical Properties of ZnO Films and Quantum Wells
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作者 张保平 康俊勇 +2 位作者 余金中 王启明 濑川勇三郎 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第4期613-622,共10页
The growth characteristics during metalorganic chemical vapor deposition and optical properties of ZnO films on sapphire (Al2O3) (0001) and (1120) substrates are studied. For the former,the effects of two import... The growth characteristics during metalorganic chemical vapor deposition and optical properties of ZnO films on sapphire (Al2O3) (0001) and (1120) substrates are studied. For the former,the effects of two important growth parameters,i, e. temperature and pressure, are investigated in detail. Due to the large lattice mismatch between the film and the substrate, ZnO nanocrystals are usually obtained. The growth behavior at the film-substrate interface is found to be strongly dependent on the growth temperature,while the growth pressure determines the shape of the nanostructures as they grow. It is difficult to obtain ZnO films that have good quality and a smooth surface simultaneously. Due to the smaller lattice mismatch,the critical thickness of ZnO on the Al2O3 (1120) surface is found to be much larger than that on the Al2O3 (0001) surface. ZnO/MgZnO quantum wells with graded well thicknesses are grown on the Al2O3 (1120) surfaces,and their optical properties are studied. The built-in electric field in the well layer, generated by the piezoelectric effect, is estimated to be 3 × 10^5 V/cm. It is found that growth at low temperatures and low pressures may facilitate the incorporation of acceptor impurities in ZnO. 展开更多
关键词 ZnO thin films quantum well MOCVD growth temperature DOPING
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Atomic Design of Polarity of GaN Films Grown on SIC(0001)
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作者 DAIXian-Qi WUHua-Sheng +2 位作者 XUShi-Hong XIEMao-Hai S.Y.Tong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第4期609-613,共5页
Ab initio total energy calculations are used to determine the interface structure of GaN films grown on 6H-SiC(0001)with different substrate reconstructions.The results indicate that GaN films grown on bare SiC(0001)a... Ab initio total energy calculations are used to determine the interface structure of GaN films grown on 6H-SiC(0001)with different substrate reconstructions.The results indicate that GaN films grown on bare SiC(0001)are of the Ga-polarity,while GaN films grown on SiC(0001)with Si adlayer are of the N-polarity if there is no N-Si interchange at the interface.With the interchange,the GaN films are of the Ga-polarity. 展开更多
关键词 polarity total energy calculation ADLAYER INTERFACE
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Surface characteristics and structure of oxide films containing Ca and P on Ti substrate
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作者 刘福 宋英 +3 位作者 王福平 清水纪夫 五十岚香 赵连城 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2005年第2期201-204,共4页
The oxide films were obtained in an electrolyte of calcium glycerphosphate (Ca-GP) and calcium acetate (CA) by microarc oxidation (MAO). The oxide films displayed a porous and rough structure on the film surface, and ... The oxide films were obtained in an electrolyte of calcium glycerphosphate (Ca-GP) and calcium acetate (CA) by microarc oxidation (MAO). The oxide films displayed a porous and rough structure on the film surface, and the roughness tended to increase with increasing voltage of microarc oxidation. The oxide film exhibited a uniform coating and tends to be well boned to the substrate. The thickness of oxide films depended on the final voltage at a constant concentration of electrolyte solution. Ca and P were also incorporated into the oxide film during the microarc oxidation process. It was found that the electrolyte of calcium glycerphosphate (Ca-GP) and calcium acetate (CA) was suitable for microarc oxidation to form oxide film containing Ca and P on Ti substrate. The concentration of Ca and P were 11.6 at% and 6.4 at%, respectively, when microarc oxidation was performed in the electrolyte of 0.06 M Ca-GP and 0.25 M CA at current density 50 A/m^2 and final voltage 350 V. The composition of the Ca, P and Ti changed during depth profiling. The crystalline phases were only anatase when final voltage was below 300 V and rutile was presented when voltage was up to 350 V. The microstructure, phase structure and phase composition were investigated by scanning electron microscopy (SEM), atomic force microscope (AFM), energy dispersive X-ray microanalyser (EDX), and X-ray diffraction (XRD). 展开更多
关键词 microarc oxidation oxide film TITANIUM BIOMATERIALS
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Effect of Substrate Nitridation on Properties of Thick GaN Film Grown by Hydride Vapour Phase Epitaxy
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作者 YEHao-hua YUGuang-hui +2 位作者 LEIBen-lian QIMing LIAi-zhen 《Semiconductor Photonics and Technology》 CAS 2005年第1期28-31,共4页
Thick GaN films were grown on the sapphire substrate by hydride vapour phase epitaxy. The properties of GaN films were found to be significantly influenced by the duration of exposing the sapphire substrate to ammonia... Thick GaN films were grown on the sapphire substrate by hydride vapour phase epitaxy. The properties of GaN films were found to be significantly influenced by the duration of exposing the sapphire substrate to ammonia prior to the GaN growth initiation. The crystalline quality of GaN films revealed by high resolution X-ray diffraction were strongly dependent on the nitridation time, which determined substrate surface topography. The different nitridation schemes strongly affected the morphology of GaN overlayers resulting in the blue shift of the main excitonic peak in photoluminescence spectra at room temperature. 展开更多
关键词 substrate nitridation GaN hydride vapour phase epitaxy
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Self-Organizing Evolution of Anodized Oxide Films on Ti-25Nb-3Mo-2Sn-3Zr Alloy and Hydrophilicity
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作者 何芳 李立军 +2 位作者 陈利霞 李凤娇 黄远 《Transactions of Tianjin University》 EI CAS 2014年第2期97-102,共6页
In the present work,hierarchical nanostructured titanium dioxide(TiO2) films were fabricated on Ti-25Nb-3Mo-2Sn-3Zr(TLM) alloy for biomedical applications via one-step anodization process in ethylene glycolbased elect... In the present work,hierarchical nanostructured titanium dioxide(TiO2) films were fabricated on Ti-25Nb-3Mo-2Sn-3Zr(TLM) alloy for biomedical applications via one-step anodization process in ethylene glycolbased electrolyte containing 0.5wt% NH4F.The nanostructured TiO2 films exhibited three distinct types depending on the anodization time:top irregular nanopores(INP)/beneath regular nanopores(RNP),top INP/middle regular nanotubes(RNT)/bottom RNP and top RNT with underlying RNP.The evolution of the nanostructured TiO2 films with anodization time demonstrated that self-organizing nanopores formed at the very beginning and individual nanotubes originated from underlying nanopore dissolution.Furthermore,a modified two-stage self-organizing mechanism was introduced to illustrate the growth of the nanostructured TiO2 films.Compared with TLM titanium alloy matrix,the TiO2 films with special nano-structure hold better hydrophilicity and higher specific surface area,which lays the foundation for their biomedical applications. 展开更多
关键词 Ti-25Nb-3Mo-2Sn-3Zr alloy hierarchical nanostructured oxide layers anodization HYDROPHILICITY
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The Formation of Nano-Size SiO_2 Thin Film on an Aluminum Plate with Hexamethyldisilazane (HMDSA) and Hexamethyldisiloxane (HMDSO) 被引量:3
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作者 H.K.Ma E.Zhao +1 位作者 K.M.Chung C.L.Yeh 《Journal of Thermal Science》 SCIE EI CAS CSCD 2003年第1期89-96,共8页
This study is using HMDSA (C6H19NSi2) or HMDSO (C6H18OSi2) vapor into C3H8/air premixed flames to form SiO2 thin film on the surface of an aluminum plate. With the addition of HMDSO or HMDSA to premixed flames, an ora... This study is using HMDSA (C6H19NSi2) or HMDSO (C6H18OSi2) vapor into C3H8/air premixed flames to form SiO2 thin film on the surface of an aluminum plate. With the addition of HMDSO or HMDSA to premixed flames, an orange secondary flame or a flame brush appeared and was contributed to the formation of Sio2 particles. Based upon the EDS, XPS and FTIR analysis, it is believed that the synthesized products consist of mainly SiO2 and a small amount of SiO. The pure SiO2 crystal structure, was proved by XRD analysis, which may form from the SiO2 amorphous structure after high temperature (1300C) thermal treatment. The nano-size SiO2 particles, which ranged from 2.5-25 nm, are proved by analysis of the BET and TEM. A 2-D CFD-RC code with 12 reduced chemical reaction mechanism, based upon the SIMPLER procedure, was successfully employed to predict the flame temperature and both of the SiO2 and SiO concentration profiles. Compared with the experimental results, the calculated temperature profiles in the post-flame region are in good agreement with the measured data and observation phenomena. 展开更多
关键词 nano size thin film SiO2.
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Growth and low-energy electron microscopy characteri- zation of monolayer hexagonal boron nitride on epitaxial cobalt 被引量:7
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作者 Carlo M. Orofeo Satoru Suzuki Hiroyuki Kageshima Hiroki Hibino 《Nano Research》 SCIE EI CAS CSCD 2013年第5期335-347,共13页
Low-energy electron microscopy (LEEM) has been used to study the structure, initial growth orientation, growth progression, and the number of layers of atomically thin hexagonal boron nitride (h-BN) films. The h-B... Low-energy electron microscopy (LEEM) has been used to study the structure, initial growth orientation, growth progression, and the number of layers of atomically thin hexagonal boron nitride (h-BN) films. The h-BN films are grown on heteroepitaxial Co using chemical vapor deposition (CVD) at low pressure. Our findings from LEEM studies include the growth of monolayer film having two, oppositely oriented, triangular BN domains commensurate with the Co lattice. The growth of h-BN appears to be self-limiting at a monolayer, with thicker domains only appearing in patches, presumably initiated between domain boundaries. Reflectivity measurements of the thicker h-BN films show oscillations resulting from the resonant electron transmission through quantized electronic states of the h-BN films, with the number of minima scaling up with the number of h-BN layers. First principles density functional theory (DFT) calculations show that the positions of oscillations are related to the electronic band structure of h-BN. 展开更多
关键词 chemical vapor deposition COBALT domain boundaries hexagonal boron nitride low-energy electronmicroscopy (LEEM)
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A direct atomic layer deposition method for growth of ultra-thin lubricant tungsten disulfide films 被引量:2
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作者 SUN YongFeng CHAI ZhiMin +1 位作者 LU XinChun HE DanNong 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2017年第1期51-57,共7页
We describe a direct atomic layer deposition method to grow lubricant tungsten disulfide (WS2) films. The WS2 films were deposited on a Si (100) substrate and a zinc sulfide (ZnS) film coated the Si (100) subs... We describe a direct atomic layer deposition method to grow lubricant tungsten disulfide (WS2) films. The WS2 films were deposited on a Si (100) substrate and a zinc sulfide (ZnS) film coated the Si (100) substrate using tungsten hexacarbonyl and hydrogen sulfide as precursors. The ZnS film served as an intermediate layer to facilitate the nucleation and growth of the WS2 films. The thickness of the WS2 films was measured via scanning electron microscope, the microstructure was probed with an X-ray diffractometer and a transmission electron microscope. The friction coefficient was measured with a ball-on-disk tester under dry nitrogen. The results reveal that the WS2 films deposited on both substrates are N175 nm and have (002) and (101) crystal orientations. The WS2 film deposited on the ZnS coated Si substrate exhibits a stronger (002) orientation and a denser crystal structure than that deposited on the Si substrate. The WS2 films on both substrates have low friction coefficients. How- ever, due to the stronger (002) orientation and denser crystal structure, the friction coefficient of the WS2 film deposited on ZnS coated Si substrate is smaller with longer wear life. 展开更多
关键词 atomic layer deposition tungsten disulfide crystal orientation FRICTION
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Growth and in situ high-pressure reflection high energy electron difraction monitoring of oxide thin films 被引量:1
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作者 LI Jie PENG Wei +4 位作者 CHEN Ke WANG Ping CHU HaiFeng CHEN YingFei ZHENG DongNing 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第12期2312-2326,共15页
Interface and surface physics is an important sub-discipline within condensed matter physics in recent decades. Novel concepts like oxide-electronic device are prompted, and their performance and lifetime are highly d... Interface and surface physics is an important sub-discipline within condensed matter physics in recent decades. Novel concepts like oxide-electronic device are prompted, and their performance and lifetime are highly dependent on the flatness and abruptness of the layer surfaces and interfaces. Reflection high-energy electron diffraction (RHEED), which is extremely sensitive to surface morphology, has proven to be a versatile technique for the growth study of oxide thin films. A differential pumping unit enables an implementation of RHEED to pulsed laser deposition (PLD) systems, ensuring an in situ monitoring of the film growth process in a conventional PLD working oxygen pressure up to 30 Pa. By optimizing the deposition conditions and analyzing the RHEED intensity oscillations, layer-by-layer growth mode can be attained. Thus atomic control of the film surface and unit-cell control of the film thickness become reality. This may lead to an advanced miniaturization in the oxide electronics, and more importantly the discovery of a range of emergent physical properties at the interfaces. Herein we will briefly introduce the principle of high-pressure RHEED and summarize our main results relevant to the effort toward this objective, including the growth and characterization of twinned Laz/3Caj/3MnO3 thin films and ReTiO〉6/2 (Re = La, Nd; ~5 = 0 - 1) AnBnO3n+2 structures, on YSZ-buffered 'Silicon on Insulator' and LaA103 substrates, respectively, as well as the study of the initial structure and growth dynamics of YBazCu307-6 thin films on SrTiO3 substrate. Presently we have realized in situ monitoring and growth mode control during oxide thin film deposition process. 展开更多
关键词 RHEED oxide thin film pulsed laser deposition INTERFACE
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4H-SiC trench gate MOSFETs with field plate termination 被引量:2
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作者 SONG QingWen ZHANG YuMing +1 位作者 ZHANG YiMen TANG XiaoYan 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第10期2044-2049,共6页
Field plate(FP)-terminated 4H-SiC trench gate MOSFETs are demonstrated in this work.N+/P?/N?/N+multiple epitaxial layers were grown on 3-inch N+type 4H-SiC substrate by chemical vapor deposition(CVD),and then the 4H-S... Field plate(FP)-terminated 4H-SiC trench gate MOSFETs are demonstrated in this work.N+/P?/N?/N+multiple epitaxial layers were grown on 3-inch N+type 4H-SiC substrate by chemical vapor deposition(CVD),and then the 4H-SiC trench gate MOSFETs were fabricated based on the standard trench transistor fabrication.Current-voltage measurements in forward and reverse bias have been performed on different devices with and without FP protections.It is found that more than 60%of the devices protected with FP termination are able to block 850 V.The measurements also show that the devices have the small leakage currents 0.15 nA at 600 V and 2.5 nA at 800 V,respectively.The experimental results also were compared with the simulated results,which show good agreement with each other in the trend.The limited performance of the devices is mainly because of the damage induced on the trench sidewalls from the etching process and the quality of the SiO2 films.Therefore,the 4H-SiC trench gate MOSFETs are expected to be optimized by reducing the etching damage and growing high-quality SiO2 dielectric films. 展开更多
关键词 4H-SIC MOSFET TRENCH field plate
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Oxide-on-graphene field effect bio-ready sensors 被引量:1
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作者 Bei Wang Kristi L. Liddell +3 位作者 Junjie Wang Brandon Koger Christine D. Keating Jun Zhu 《Nano Research》 SCIE EI CAS CSCD 2014年第9期1263-1270,共8页
Electrical detection schemes using nanoscale devices offer fast and label-free alternatives to biosensing techniques based on chemical and optical interactions. Here we report on the design, fabrication, and operation... Electrical detection schemes using nanoscale devices offer fast and label-free alternatives to biosensing techniques based on chemical and optical interactions. Here we report on the design, fabrication, and operation of oxide-on-graphene ion-sensitive field effect sensor arrays using large-area graphene sheets synthesized by chemical vapor deposition. In this scheme, HfO2 and SiO2 thin films are deposited atop the graphene sheet and play the dual role of the sensing interface, as well as the passivation layer protecting the channel and electrodes underneath from direct contact with the electrolyte. We further demonstrate the functionalization of the SiO2 surface with 3-aminopropyltrimethoxysilane (APTMS). The oxide-on-graphene sensors operate in solution with high stability and a high average mobility of 5,000 cm2/(V's). As a proof of principle, we demonstrate pH sensing using the bare or the APTMS-functionalized SiO2 as the sensing surface. The measured sensitivities, 46 mV/pH and 43 mV/pH, respectively, agree well with existing studies. We further show that by applying the solution gate voltage in pulse, the hysteresis in the transfer curve of the graphene transducer can be eliminated, greatly improving the ionic potential resolution of the sensor. These experiments demonstrate the potential of oxide-on-graphene ion-sensitive field effect sensors in on-chip, label-free and real-time biosensing applications. 展开更多
关键词 GRAPHENE BIOSENSOR pH sensor ISFET APTMS LABEL-FREE
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The influence of pressure on the growth of a-plane GaN on r-plane sapphire substrates by MOCVD
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作者 HE Tao LI Hui +9 位作者 DAI LongGui WANG XiaoLi CHEN Yao MA ZiGuang XU PeiQiang JIANG Yang WANG Lu JIA HaiQiang WANG WenXin CHEN Hong 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第3期446-449,共4页
Nonpolar a-plane (1120) GaN films have been grown on r-plane (1102) sapphire by metal-organic chemical vapor deposition (MOCVD) under different growth pressures. The as-grown films are investigated by optical mi... Nonpolar a-plane (1120) GaN films have been grown on r-plane (1102) sapphire by metal-organic chemical vapor deposition (MOCVD) under different growth pressures. The as-grown films are investigated by optical microscopy, high-resolution X-ray diffraction (HRXRD) and Raman scattering. As growth pressure rises from 100 mbar to 400 mbar, the surface gets rougher, and the in-plane XRD full width at half maximum (FWHM) along the c-axis [0001] increases while that along the m-axis [1100] decreases. Meanwhile, residential stresses are reduced along both the c-axis and the m-axis. The structural anisotropy feature under 400 mbar is inverted with respect to 100 mbar, and the weakened anisotropy is achieved under a moderate pressure of 200 mbar, probably due to the suppressed Ga atomic migration along the c-axis under a larger pressure. We propose that pressure can affect a-plane growth through the V/III ratio. 展开更多
关键词 GaN anisotropy XRD growth pressure MOCVD
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Research on structural characteristics of large-scale CdS thin films deposited by CBD under low ammonia condition
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作者 薛玉明 高林 +5 位作者 尹富红 乔在祥 刘浩 冯少君 孙海涛 杭伟 《Optoelectronics Letters》 EI 2015年第4期273-276,共4页
Cadmium sulfide(Cd S) buffer layers with the scale of 10 cm×10 cm are deposited by chemical bath deposition(CBD) with different temperatures and thiourea concentrations under low ammonia condition.There are obvio... Cadmium sulfide(Cd S) buffer layers with the scale of 10 cm×10 cm are deposited by chemical bath deposition(CBD) with different temperatures and thiourea concentrations under low ammonia condition.There are obvious hexagonal phases and cubic phases in Cd S thin films under the conditions of low temperature and high thiourea concentration.The main reason is that the heterogeneous reaction is dominant for homogeneous reaction.At low temperature,Cd S thin films with good uniformity and high transmittance are deposited by adjusting the thiourea concentration,and there is almost no precipitation in reaction solution.In addition,the low temperature is desired in assembly line.The transmittance and the band gap of Cd S thin films are above 80% and about 2.4 e V,respectively.These films are suitable for the buffer layers of large-scale Cu(In,Ga)Se2(CIGS) solar cells. 展开更多
关键词 ammonia transmittance hexagonal CIGS thiourea assembly cubic uniformity adjusting sulfide
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Stress control of silicon nitride films deposited by plasma enhanced chemical vapor deposition
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作者 李东玲 冯小飞 +2 位作者 温志渝 尚正国 佘引 《Optoelectronics Letters》 EI 2016年第4期285-289,共5页
Stress controllable silicon nitride(Si Nx) films deposited by plasma enhanced chemical vapor deposition(PECVD) are reported. Low stress Si Nx films were deposited in both high frequency(HF) mode and dual frequency(HF/... Stress controllable silicon nitride(Si Nx) films deposited by plasma enhanced chemical vapor deposition(PECVD) are reported. Low stress Si Nx films were deposited in both high frequency(HF) mode and dual frequency(HF/LF) mode. By optimizing process parameters, stress free(-0.27 MPa) Si Nx films were obtained with the deposition rate of 45.5 nm/min and the refractive index of 2.06. Furthermore, at HF/LF mode, the stress is significantly influenced by LF ratio and LF power, and can be controlled to be 10 MPa with the LF ratio of 17% and LF power of 150 W. However, LF power has a little effect on the deposition rate due to the interaction between HF power and LF power. The deposited Si Nx films have good mechanical and optical properties, low deposition temperature and controllable stress, and can be widely used in integrated circuit(IC), micro-electro-mechanical systems(MEMS) and bio-MEMS. 展开更多
关键词 DEPOSITION Deposition rates Integrated circuits MEMS Nitrides Optical properties Plasma CVD Refractive index Silicon nitride Stresses Vapor deposition
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