空气分子污染探讨

介绍空气分子污染(AMC)的定义、国际标准AMC分级、国外污染物分类、洁净室AMC路径、AMC控制设施。     

洁净室气态分子污染物的监测技术

随着微电子工业工序复杂性的增加和产品尺寸的不断缩小,气态分子污染物(AMC)对产品的影响成为洁净室环境控制中重点关注的问题。文章介绍了洁净室中AMC的定义,重点阐述了AMC的监测技术。     

净化厂房中气相分子沾污(AMC)的来源和危害

越来越多的研究发现,在半导体圆片加工净化厂房中,除了存在空气悬浮颗粒沾污外,还存在以气相或蒸汽形式存在的分子污染物(Airborne Molecular Contaminants,AMC)。随着特征尺寸(CD)的不断缩小,AMC将会越来越严重地影响圆片加工质量和成品率,并会影响净化厂房内工作人员的身体健康。文章介绍了AMC的分类、来源、危害性、控制标准和方法,希望以此引起人们对AMC的重视,并采取相应的控制措施。     

AMC1200：隔离式放大器

德州仪器宣布推出一款隔离式放大器，适合电机控制与绿色能源应用。该AMC1200隔离式放大器与AMC1204△∑型调制器可帮助设计人员提高AC驱动器、太阳能逆变器以及不间断电源等设备的精确性、温度稳定性以及磁场抗扰性。     

控创:倡导"AMC,everywhere"最新理念

日前,德国控创电信事业拓展部经理Tom Meyer再次来到中国,此次中国之行,他带来了一个名为“AMC,everywhere”的最新理念。这一理念的提出,正是其在ATCA插卡方面取得最新进展的一个体现。AMC:真的能无所不在吗?AMC(Advanced MezzanineCard)的规范(PICMG AMC.0、AMC.1、AMC.2和AMC.3)主要定义了能够支持热插拔功能和现场可更换功能的插卡,主要面向高可用性的电信系统。AMC通过采用各种高速串行接口与载板通信,包括千兆以太网和PCIExpress,或者采取在背板上直接使用AMC技术。Tom Meyer认为,在通信领域可以利用这一技术扩充…     

谈300mm晶圆厂洁净室光刻区域环境中NH_3和SO_2的控制

在半导体业中,对生产作业环境要求极为严格,其中对AMC(AirborneMolecularContami-nation)有更严格的控制要求。SO2和NH3属于AMC中的2种,即MA(分子酸)和MB(分子碱)。主要讨论洁净室中NH3和SO2的含量对晶圆和光罩的影响,以及采取各种有效措施对其进行控制,满足先进制程对于产品生产的超高空气品质要求。     

WiMAX 802.16e的链路自适应机制

文章在分析WiMAX 802.16e链路自适应控制机制的基础上,探讨了AMC、HARQ、MIMO等几种目前在WiMAX系统中具有较高的应用价值的链路自适应技术。     

通信与网络

B 结构压入式AMC连接器HARTING推出新型的B 结构的压入式AMC连接器,适用于AdvancedTCA。该连接器能够满足PICMG(PCI Industrial Computer Manufactures Group)AMC．0的机械和电气需求,而且使用压入方式。压入方式是AMC．0的下一修订版的要求。     

有效控制AMC的化学过滤方案

AMC对微电子制程存在潜在严重危害并会导致成品率降低.将传统检测方法和Gigacheck或Gigamonitor相结合,会得到更多的AMC信息.化学过滤器是去除AMC的有效手段,评价化学过滤器的指标不仅要考察吸附效率、吸附容量等指标,还必须对化学过滤器整体进行测试,从而能够提供对特定的AMC有很强针对性和突出去除效果的化学过滤解决方案.     

气态分子污染物的控制研究

首先从取样与分析着手研究。分析了设施内外的空气质量,识别出目标污染物以及那些可能影响气态分子污染(AMC)控制系统性能的物质;其次,针对AMC的种类与水平,提出AMC控制系统选择并验证方法;最后,提出对受控环境以及AMC控制系统的性能实施定期定点的监测要求与措施,是指导AMC控制系统不断优化的依据。     

AMC-Based Transmission of Resource Allocation Messages for Short-Sized Packet Services

We introduce a scheme that applies adaptive modulation and coding (AMC) to the transmission of resource allocation messages, and show that the AMC transmission of control messages reduces control overhead and is particularly effective for services with small-sized packets, such as VoIP.     

Adaptive modulation and coding for Long Term Evolution‐based mobile satellite communication system

The adaptive modulation and coding (AMC) scheme is mandatory for modern wireless communication systems to overcome inevitable channel impairments. Many of the limitations using AMC are due to the long round‐trip delay of a satellite system. This paper proposes an efficient AMC scheme with power control and symbol interleaving that can be effectively applied to satellite systems. In particular, we focus on mobile satellite systems that have maximum compatibility in a Long Term Evolution system. Simulations reveal that the proposed scheme can provide a maximum 10.2% increase of average beam spectral efficiency and a maximum of 8‐dB power gain compared with a conventional AMC scheme. Copyright © 2012 John Wiley & Sons, Ltd.     

Non-cooperative power control game for adaptive modulation and coding

Adaptive modulation and coding (AMC) provides the flexibility to match modulation and coding scheme (MCS) to signal to interference plus noise ratio (SINR) of users. To reduce the transmission power and maintain the transmission quality, power control is normally combined with AMC. While the target SINR of power control is fixed, therefore non-cooperative power control game for AMC (NPGA) algorithm was proposed to adapt to the dynamic target SINR changes according to MCS. In NPGA, we formulate system transmission efficiency via utility, where the utility function is constructed based on the modulation and coding efficiency with non-cooperative game theory. It is demonstrated theoretically that NPGA can satisfy the conditions of the supermodular games, and its solution is optimal. The simulation results show that NPGA can improve system transmission efficiency and signal quality with low transmission power, and the convergence performance of NPGA is more fast-effectiveness compared with geometric programming algorithms.     

Adaptive-Modulation-and-Coding-Based Transmission of Control Messages for Resource Allocation in Mobile Communication Systems

In general, link-adaptive schemes, such as adaptive modulation and coding (AMC) and hybrid automatic repeat request (HARQ), enhance system capacity in time-varying wireless channels. For these link-adaptive schemes to be applied, resources have to be adaptively and dynamically allocated every frame. Thus, the system needs control messages to send information to users about dynamic resource allocation. Such information includes user ID, resource position, level of modulation, and coding and automatic repeat request (ARQ) information. However, the transmission of these resource-allocation messages causes control overhead. In this paper, we introduce a scheme that applies AMC to the transmission of resource-allocation messages and analyze its performance in systems that support truncated ARQ, such as link-layer ARQ and HARQ. In addition, we show that using AMC to transmit control messages is a good way to reduce control overhead; in particular, it is very effective when the number of users per frame is large, as in voice over Internet Protocol (VoIP) services.      

Active‐Matrix Field Emission Display with Amorphous Silicon Thin‐Film Transistors and Mo‐Tip Field Emitter Arrays

We present, for the first time, a prototype active‐matrix field emission display (AMFED) in which an amorphous silicon thin‐film transistor (a‐Si TFT) and a molybdenum‐tip field emitter array (Mo‐tip FEA) were monolithically integrated on a glass substrate for a novel active‐matrix cathode (AMC) plate. The fabricated AMFED showed good display images with a low‐voltage scan and data signals irrespective of a high voltage for field emissions. We introduced a light shield layer of metal into our AMC to reduce the photo leakage and back channel currents of the a‐Si TFT. We designed the light shield to act as a focusing grid to focus emitted electron beams from the AMC onto the corresponding anode pixel. The thin film depositions in the a‐Si TFTs were performed at a high temperature of above 360°C to guarantee the vacuum packaging of the AMC and anode plates. We also developed a novel wet etching process for n⁺‐doped a‐Si etching with high etch selectivity to intrinsic a‐Si and used it in the fabrication of an inverted stagger TFT with a very thin active layer. The developed a‐Si TFTs performed well enough to be used as control devices for AMCs. The gate bias of the a‐Si TFTs well controlled the field emission currents of the AMC plates. The AMFED with these AMC plates showed low‐voltage matrix addressing, good stability and reliability of field emission, and good light emissions from the anode plate with phosphors.     

The removal of airborne molecular contamination in cleanroom using PTFE and chemical filters

Cleanroom contamination and its impact on the performance of devices are beginning to be investigated due to the increasing sensitivity of the semiconductor manufacturing process to airborne molecular contamination (AMC). A clean bench was equipped with different filter modules and then most AMC in the cleanroom and in the clean bench was detected through air-sampling and wafer-sampling experiments. Additionally, the effect of AMC on device performance was examined by electrical characterization. A combination of the NEUROFINE PTFE filter and chemical filters was found to control metal, organic, and inorganic contamination. We believe that the new combination of filters can be used to improve the manufacturing environment of devices, which are being continuously shrunk to the nanometer scale.     

Service differentiation in multirate wireless networks with weighted round-robin scheduling and ARQ-based error control

The radio link-level delay statistics in a wireless network using adaptive modulation and coding (AMC), weighted round-robin (WRR) scheduling, and automatic repeat request-based error control is analyzed in this letter. WRR scheduling can be used for service differentiation similar to that achievable by using the generalized processor sharing scheduling discipline. The analytical framework presented in this letter captures physical and radio link-level aspects of a multirate multiuser wireless network (e.g., general fading model, AMC, scheduling, error control) in a unified way. It can be used for admission control and cross-layer design under statistical delay constraints. The analytical results are validated by simulations. Typical numerical results are presented, and their useful implications on the system performance are discussed.