感应耦合等离子刻蚀InP工艺

采用Cl2/CH4/N2感应耦合等离子体对InP进行了刻蚀.系统地讨论了RF功率、ICP功率、反应腔压力、气体流量等工艺参数对InP材料端面刻蚀的影响.通过优化工艺参数,获得了光滑垂直的InP刻蚀端面,刻蚀速率达到841 nm/min,与SiO2的选择比达到15:1.     

基于多掩膜光刻工艺的MEMS体硅加工

本文提出了一种新颖的MEMS多掩膜工艺,实现了带有大台阶和大深宽比窄槽的衬底上的体硅精细加工。通过薄胶多次光刻在衬底上制作出氧化硅(SiO2)、氮化硅(Si3N4)、光刻胶(photo-resist,PR)等材料的多层掩膜图形,每层掩膜可以进行一次衬底刻蚀或腐蚀,刻蚀或腐蚀完毕后去除该层掩膜。该工艺解决了MEMS工艺中的深坑涂胶和光刻问题,结合深反应离子刻蚀(Deep Re-active Ion Etching,DR IE)、湿法腐蚀等工艺可以用于多级台阶、深坑底部精细结构、微结构释放等MEMS工艺。     

掩膜对GaAs基二维光子晶体ICP刻蚀效果的影响

结合刻蚀GaAs基光子晶体在光子晶体垂直腔面发射激光器中的应用,研究了光刻胶、SiO2掩膜的特性以及对GaAs基二维光子晶体ICP刻蚀效果的影响,并分析了ICP刻蚀小尺寸光子晶体时,造成底面凹凸不平、侧壁粗糙、垂直度差的原因.最后,调整工艺条件,利用BP212-7CP光刻胶做掩膜,成功制作了直径为1.2～4.0μm、深度为1.5μm的侧壁光滑垂直、底面平整的高质量光子晶体结构.     

GaAs材料ICP刻蚀中光刻胶厚度及刻蚀条件对侧壁倾斜度的影响

使用感应耦合等离子体(ICP)刻蚀技术刻蚀GaAs材料,在光刻过程中采用不同厚度的光刻胶,研究在同一刻蚀条件下不同光刻胶厚度对刻蚀图形侧壁倾斜度的影响,并研究了光刻胶厚度对侧壁倾角影响在不同大小图形刻蚀中的尺寸效应,提出了关于刻蚀机理的尺寸增益现象及可能发生的刻蚀离子的散射模型,解释了光刻胶厚度较大时小线宽图形侧壁倾角...     

类金刚石薄膜的反应离子刻蚀

为了刻蚀出图形完整、侧壁陡直、失真度小、独立的类金刚石薄膜微器件,反应离子刻蚀是一种有效地刻蚀方法。研究了氧气与氩气的混合气体进行类金刚石薄膜刻蚀的主要工艺参数(刻蚀时间、有无掩膜、氩氧体积混合比、负偏压)。研究结果表明:在相同条件下,刻蚀速率随刻蚀时间变化不大;有无掩膜对刻蚀速率无明显影响;流量一定时,刻蚀速率随氩氧体积比的增大而降低,随负偏压的增大先增大后减小。实验得到最佳刻蚀条件,在此条件下,刻蚀出图形完整、侧壁陡直、失真度小的微器件,并成功制备出"独立"的微齿轮,进行了组装。     

在晶元级Si衬底上制备高深宽比SiO_2周期图形（英文）

本文主要介绍了通过步进式光刻、反相剥离和F基等离子体刻蚀工艺在晶元级Si衬底上制备SiO_2图形的过程,在6 in(15.24 cm)Si衬底上实现了均匀的周期分别为1.0μm和1.6μm、深宽比分别为2.3和1.4的SiO_2周期性掩膜.尤其在周期为1μm的条件下,窗口通过过曝光和反相剥离工艺减小到330 nm,该尺寸超越了试验用步进式光刻设备的极限精度尺寸.在通过HF和KOH溶液处理后,得到了带有V型槽和较光滑侧壁的SiO图形的Si衬底,该图形适用于Ⅲ-Ⅴ半导体通过深宽比位错捕获技术的材料生长.这种均匀的晶元级图案制备方案促进了图形化Si衬底技术和Si基Ⅲ-Ⅴ半导体异质外延.     

用于微等离子体无掩膜刻蚀的微悬臂梁探针的设计和加工

设计了一种用于微等离子体无掩膜刻蚀加工的微悬臂梁探针结构,即将微等离子体放电器集成在SiO2悬臂梁探针端部的空心针尖上,等离子体从针尖处的纳米孔导出,以实现高精度、高效率的无掩膜扫描刻蚀加工.设计了该悬臂梁探针的加工工艺流程,即对(100)硅片进行各向异性湿法刻蚀得到倒金字塔槽,并双面氧化,然后依次沉积并图形化微放电器的上、下电极和绝缘层,最后背面释放出带空心针尖的SiO2悬臂梁,并加工出针尖尖端的纳米孔.成功制作出质量良好、具有很高成品率的带薄壁空心针尖的SiO2悬臂梁探针阵列及倒金字塔型微放电器.实验结果表明,该微放电器能在3～15 kPa的SF6气体中稳定放电,为悬臂梁探针阵列和微放电器的工艺集成以及Si基材料的无掩膜扫描刻蚀加工奠定基础.     

Cl2/Ar感应耦合等离子体刻蚀InP工艺研究

采用Cl2／Ar感应耦合等离子体对InP进行了刻蚀。讨论了直流自偏压、ICP功率、气体总流量和气体组分等因素对刻蚀速率和粗糙度的影响。结果表明Cl2／Ar气体组分是决定刻蚀效果的重要因素。当Cl2含量为30％左右时,刻蚀中的物理溅射与化学反应过程趋于平衡,刻蚀速率处于峰值区,同时刻蚀粗糙度也可达到最小值。SEM照片显示刻蚀表面光洁。侧壁陡直。     

PMMA的反应离子深刻蚀

对PMMA进行反应离子深刻蚀以获得高深度比微结构.研究了纯氧刻蚀气体中加入CHF3对刻蚀速率、图形形貌等的影响.纯氧刻蚀PMMA,钻蚀现象严重.加入CHF3后,刻蚀速率随CHF3含量增加而下降.加入适量CHF3,可以在侧壁形成钝化层,保护侧壁不受钻蚀.当CHF3含量为40%,刻蚀功率30 W,工作气压为4 Pa时,即使刻蚀深度达到400 μm,侧壁仍然陡直,刻蚀深宽比大于10.     

电子回旋共振CF4＋O2等离子体中Si3N4刻蚀工艺研究

在一台自行研制的电子回旋共振(ECR)刻蚀系统中用CF4、O2气体实现了Si3N4材料的微细图形刻蚀。获得了气体流量、气体混合比、微波功率等因素对刻蚀速率的影响。结果表明刻蚀速率在O2含量为0％时最慢，然后随着气体混合比的增加而增大，当气体中O2含量为20％时达到最大，然后随着气体混合比的增加而缓慢降低。保持气体混合比为20％，刻蚀速率随气体流量增加而增大；同时，微波功率越大，刻蚀速率也越高。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.