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Experimental demonstration of high-Q mrr based on a germanium-on-insulator platform with an yttria insulator in the mid-IR range

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Photonics Research 2023年第11期11卷 I0017-I0024页

作者： JINHA LIM JOONSUP SHIM INKI KIM SANGHYEON KIM School of Electrical Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea

We experimentally demonstrate an all-pass microring resonator (mrr) based on a Y_(2)O_(3)BOX germanium-oninsulator (GeOI) platform operating in the mid-IR region.The ring resonator was numerically designed to have a high quality (Q) factor in the 4.18μm to 4.22μm wavelength range in the fundamental TE mode.According to our design,the GeOI ring resonator was fabricated by the direct wafer-bonding technology with an yttria(Y_(2)O_(3)) buried oxide layer,which is transparent at the mid-IR region,for the bonding interface and the electron beam lithography.The experimental resonant characteristic was obtained using our fiber-based mid-IR measurement setup.The GeOI single mrr exhibited an extinction ratio (ER) of 15.28 dB and an insertion loss (IL)of 1.204 dB,and the racetrack showed an ER of 22.77 dB and an IL of 0.627 dB.Furthermore,the free spectral range of the device was 5.29 nm,and the loaded Q factor of 94,528 (176,158 of intrinsic Q factor) was extracted by the nonlinear least squares method.We believe this demonstration of our GeOI mrr offers a valuable opportunity to implement multipurpose devices such as optical sensors,switches,and filters in the mid-IR range.

关键词： resonator insulator mrr

Photonic integrated circuit components based on amorphous silicon-on-insulator technology

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Photonics Research 2016年第3期4卷 126-134页

作者： Timo Lipka Lennart Moldenhauer Jorg Muller Hoc Khiem Trieu Institute of Microsystems Technology Hamburg University of Technology

We present integrated-optic building blocks and functional photonic devices based on amorphous siliconon-insulator technology. Efficient deep-etched fiber-to-chip grating couplers, low-loss single-mode photonic wire waveguides, and compact power splitters are presented. Based on the sub-μm photonic wires, 2 × 2 Mach–Zehnder interferometers and add/drop microring resonators(mrrs) with low device footprints and high finesse up to 200 were realized and studied. Compact polarization rotators and splitters with ≥10 d B polarization extinction ratio were fabricated for the polarization management on-chip. The tuning and trimming capabilities of the material platform are demonstrated with efficient microheaters and a permanent device trimming method, which enabled the realization of energy-efficient photonic circuits. Wavelength multiplexers in the form of cascaded filter banks and 4 × 4 routers based on mrr switches are presented. Fabrication imperfections were analyzed and permanently corrected by an accurate laser-trimming method, thus enabling eight-channel multiplexers with record low metrics of sub-m W static power consumption and ≤1°C temperature overhead. The high quality of the functional devices, the high tuning efficiency, and the excellent trimming capabilities demonstrate the potential to realize low-cost, densely integrated, and ultralow-power 3D-stacked photonic circuits on top of CMOS microelectronics.

关键词： Photonic integrated circuit components based on amorphous silicon-on-insulator technology SOI mrr OADM

Effect of Abrasive Concentration on Chemical Mechanical Polishing of Sapphire

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Chinese Physics Letters 2015年第8期32卷 181-184页

作者：闫未霞张泽芳郭晓慧刘卫丽宋志棠 State Key Laboratory of Functional Materials for Informatics Laboratory of Nanotechnology Shanghai Institute of Microsystem and Information Technology Shanghai 200050 University of Chinese Academy of Sciences Beijing 100049

Effects of abrasive concentration on material removal rate Cmrr） and surtace quality m the chemical mecnamcal polishing （CMP） of light-emitting diode sapphire substrates are investigated. Experimental results show that the mrr increases linearly with the abrasive concentration, while the rms roughness decreases with the increasing abrasive concentration. In addition, the in situ coefficient of friction （COF） is also conducted during the sapphire polishing process. The results present that COF increases sharply with the abrasive concentration up to 20 wt% and then shows a slight decrease from 20wt% to 40wt%. Temperature is a product of the friction force that is proportional to COF, which is an indicator for the mechanism of the sapphire CMP.

关键词： COF Effect of Abrasive Concentration on Chemical Mechanical Polishing of Sapphire CMP mrr

Personalized News Recommendation Based on the Text and Image Integration

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Computers, Materials & Continua 2020年第7期64卷 557-570页

作者： Kehua Yang Shaosong Long Wei Zhang Jiqing Yao Jing Liu College of Computer Science and Electronic Engineering and Key Laboratory for Embedded and Network Computing of Hunan Province Hunan UniversityChangsha410082China Oath Verizon Company New York10007USA

The personalized news recommendation has been very popular in the news recommendation field.In most research,the picture information in the news is ignored,but the information conveyed to the users through pictures is more intuitive and more likely to affect the users’reading interests than the one in the textual form.Therefore,in this paper,a model that combines images and texts in the news is proposed.In this model,the new tags are extracted from the images and texts in the news,and based on these new tags,an adaptive tag(AT)algorithm is proposed.The AT algorithm selects the tags the user is interested in based on the user feedback.In particular,the AT algorithm can predict tags that a user may be interested in with the help of the tag correlation graph without any user feedback.The proposed AT algorithm is verified by experiments.The experimental results verified the AT algorithm regarding three evaluation indexes F1-score(F1),area under curve(AUC)and mean reciprocal rank(mrr).The recommended effect of the proposed algorithm is found to be better than those of the various baseline algorithms on real-world datasets.

关键词： News recommendation F1 AUC mrr feedback correlation graph

A greedy selection approach for query suggestion diversification in search systems

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Science China(Information Sciences) 2016年第11期59卷 227-229页

作者： Fei CAI Honghui CHEN Zhen SHU Science and Technology on Information Systems Engineering Laboratory National University of Defense Technology University of Amsterdam

Dear editor,Query suggestion is a widely known and well embedded mechanism in modern search systems to facilitate the task of formulating queries.The goal is to accurately predict user’s intended query with only few keystrokes(i.e.,typed prefix),thereby helping the user formulate a satisfactory query with less effort and avoid misspelling it as well.Suggested candidates are typically generated based on previous queries that have been

关键词： A greedy selection approach for query suggestion diversification in search systems mrr MMR DCG ODP

Multivariate rational regression and its application in semiconductor device modeling

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Journal of Semiconductors 2018年第9期39卷 67-73页

作者： Yuxi Hong Dongsheng Ma Zuochang Ye Institute of Microelectronics Tsinghua University

Physics equation-based semiconductor device modeling is accurate but time and money consuming.The need for studying new material and devices is increasing so that there has to be an efficient and accurate device modeling method. In this paper, two methods based on multivariate rational regression（mrr） for device modeling are proposed. They are single-pole mrr and double-pole mrr. The two mrr methods are proved to be powerful in nonlinear curve fitting and have good numerical stability. Two methods are compared with OLS and LASSO by fitting the SMIC 40 nm MOS-FET I–V characteristic curve and the normalized mean square error of Single-pole mrr is 3.02 × 10^-8 which is 4 magnitudes less than an ordinary least square. The I–V characteristics of CNT-FET and performance indicators（noise factor, gain, power） of a low noise amplifier are also modeled by using mrr methods. The results show mrr methods are very powerful methods for semiconductor device modeling and have a strong nonlinear curve fitting ability.

关键词： multivariate rational regression mrr semiconductor device modeling vector fitting

紫外光催化辅助Ga面GaN化学机械抛光试验研究

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表面技术 2023年

作者：杨友明周海胡士响夏丽琴任相璞盐城工学院机械工程学院

目的:为了探究氮化镓晶片Ga面在紫外光催化辅助抛光过程中，相关因素对其去除率(mrr)及表面粗糙度(Ra)的影响规律，提高单晶氮化镓高效率低损伤的超光滑表面质量。方法:通过结合紫外光与化学机械共同作用进行抛光，采用单因素试验方案，... 详细信息

目的:为了探究氮化镓晶片Ga面在紫外光催化辅助抛光过程中，相关因素对其去除率(mrr)及表面粗糙度(Ra)的影响规律，提高单晶氮化镓高效率低损伤的超光滑表面质量。方法:通过结合紫外光与化学机械共同作用进行抛光，采用单因素试验方案，对GaN晶片Ga面进行紫外光催化辅助化学机械抛光试验，比较在无光照、光照抛光盘、光照抛光液等三种抛光方式和不同TiO2浓度、pH值、H2O2含量、抛光压力、抛光盘转速和抛光液流量等因素下抛光效果。最后通过正交试验进行抛光工艺参数优化，通过测量不同条件下紫外光催化辅助化学机械抛光过程中mrr和Ra值，探究对GaN晶片Ga面抛光效果。结果:试验表明，在紫外光催化辅助抛光条件下，通过对单因素试验和正交实验的抛光参数分析和优化，GaN晶片材料去除率mrr可以达到698.864 nm/h，通过白光干涉仪观测可以获得表面粗糙度Ra值为0.430 nm的亚纳米级超光滑GaN晶体表面。结论:基于紫外光催化辅助GaN晶片Ga面化学机械抛光试验，紫外光辅助化学机械的复合抛光方式能够促进GaN表面生成物Ga2O3快速去除，其中光照抛光液方式能够极大地提高抛光效率。紫外光催化辅助Ga面GaN化学机械抛光可以获得高效低损伤的单晶氮化镓抛光加工表面质量。

关键词：氮化镓紫外光催化抛光 mrr Ra 单因素试验正交试验

Material removal model for non-contact chemical mechanical polishing

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Chinese Science Bulletin 2008年第23期53卷 3746-3752页

作者： ZHANG JianQun ZHANG ChaoHui School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Beijing 100044 China

Material removal mechanism under non-contact condition between the pad and the wafer in the chemical mechanical polishing (CMP) process is investigated. Based on the assumption that almost all effective material removals take place due to the active abrasives which cut material through the plowing effects. A novel model is developed to predict the material removal rate (mrr) under non-contact condition between the pad and the wafer in CMP. Validated by the experimental data, the model is proved to be able to predict the change of mrr under non-contact condition. Numerical simulation of the model shows: the relative velocity u between the pad and the wafer and fluid viscosity η are the most important factors which impact mrr under non-contact condition; load changes of wafer also affects the mrr, but the effect is not as obvious as the relative velocity and fluid viscosity; when the radius of abrasive is not less than 50nm, the impact of mrr alone with the changes in the size of the abrasive can be ignored.

关键词： CMP 非接触条件材料移动原理 mrr

电极材料对直流短电弧铣削Ti2AlNb加工性能影响的实验研究

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制造技术与机床 2023年第9期 39-43页

作者：尹先和周建平许燕新疆大学机械工程学院新疆乌鲁木齐830047

Ti2AlNb作为一种新型航空发动机关键材料,由于其高强度、刚度和蠕变抗力,使得它成为一种难加工材料。短电弧铣削(SEAM)是一种新型高效的放电加工方法,具有不受材料的硬度、强度和韧性制约等优点,已经成为难加工材料一种重要加工方法。... 详细信息

Ti2AlNb作为一种新型航空发动机关键材料,由于其高强度、刚度和蠕变抗力,使得它成为一种难加工材料。短电弧铣削(SEAM)是一种新型高效的放电加工方法,具有不受材料的硬度、强度和韧性制约等优点,已经成为难加工材料一种重要加工方法。文章以Ti2AlNb实验对象,采用钨铜和304不锈钢作为电极材料,使用直流电源研究了不同电压下SEAM的加工机理,分析了工件材料去除率(mrr)、表面粗糙度(Sa)、相对工具电极磨损率(RTWR)。此外,还对加工后Ti2AlNb的表面形态、元素分布和显微硬度进行了研究。实验结果表明,24V电压下,钨铜电极与304不锈钢电极相比,mrr最高,为1981mm^(3)/min;RTWR最低,相对电极损耗仅为0.82%。工件截面轮廓宽度尺寸绝对差异最小以及工件再铸层硬度接近母材硬度,有利于进一步加工。

关键词：直流短电弧铣削 Ti2AlNb mrr RTWR 电极材料