值得思索的中国FPC生产状态

中国的FPC应走向以刚-挠性PCB为主的新产品上。     

Characterization of the CH4/H2/Ar high density plasma etching process for HgCdTe

High density plasma etching of mercury cadmium telluride using CH₄/H₂/Ar plasma chemistries is investigated. Mass spectrometry is used to identify and monitor etch products evolving from the surface during plasma etching. The identifiable primary etch products are elemental Hg, TeH₂, and Cd(CH₃)₂. Their relative concentrations are monitored as ion and neutral fluxes (both in intensity and composition), ion energy and substrate temperature are varied. General insights are made into surface chemistry mechanisms of the etch process. These insights are evaluated by examining etch anisotropy and damage to the remaining semiconductor material. Regions of process parameter space best suited to moderate rate, anisotropic, low damage etching of HgCdTe are identified.     

Design of a Temporal Learning Chip for Signal Generation and Classification

The design and analog VLSI implementation of a recurrent neural network with integrated temporal learning is presented. The learning algorithm is forward in time, and is implemented strictly as instantaneous, local weight updates. PSpice simulations of networks with 4 to 6 neurons demonstrate robust learning of trajectory generation and classification tasks. A scalable 2-D VLSI architecture is described and a prototupe 4-neuron recurrent neural network with learning has subsequently been fabricated in MOSIS TinyChip 2 micron technology. Experimental results of the chip validate the learning performance with convergence in the millisecond range. Specific experimental results of learning circular and figure-8 dynamic trajectories are included.     

Highly reliable ECR N2O-plasma polyoxide grown on heavily phosphorus-doped polysilicon films

Reliability of polyoxide grown by electron cyclotron resonance (ECR) N₂O-plasma on heavily phosphorus-doped polysilicon has been investigated for the interpoly dielectrics (IPDs) of nonvolatile memories (NVMs). ECR N₂O-plasma polyoxide grown on polysilicon with phosphorus of 1 × 10²¹ cm⁻³ exhibits a significantly high breakdown field of 10 MV/cm and low electron trapping rate of 0.5 V, which are regardless of phosphorus concentration. The improvements are attributed to the smooth polyoxide/polysilicon interface, low phosphorus concentration, and nitrogen-rich layer with strong silicon-nitrogen bonds at the polyoxide/polysilicon interface.     

Work function difference of naphthyl end-capped oligothiophene in different crystal alignments studied by Kelvin probe force microscopy

The performance of organic semiconductor devices is strongly affected by the interface energetics at the junctions between the constituent materials. A large group of organic semiconductors consists of rodlike small molecules that crystallize upon deposition with a molecular orientation dependent on the specifics of the molecule–molecule and molecule–substrate interactions. By means of Kelvin probe force microscopy (KPFM), this work studies naphthyl end-capped oligothiophene, 5,50-bis(naphth-2-yl)-2,20-bithiophene (NaT2), deposited on samples of pristine ${\text{SiO}}_2$ and samples of graphene-covered ${\text{SiO}}_2$. The crystal molecular orientation of NaT2 is dependent on the substrate on which it is deposited. On ${\text{SiO}}_2$, the NaT2 molecules are predominately upright standing, forming crystallites with distinct terrace heights of $2.0\pm 0.1\text{nm}$. Measurements indicate formation of an initial wetting layer in the NaT2-${\text{SiO}}_2$ system for the upright standing molecules. When deposited on graphene, the molecules additionally form fibrous structures with heights of $10-115\text{nm}$ consisting of molecules lying down (face-on orientation). Using KPFM, a difference in the local contact potential difference (CPD) of upright standing NaT2 and face-on oriented structures on graphene is measured to be $-0.16\pm 0.04\text{V}$, indicating a work function difference between the two system configurations, which is confirmed through Density Functional Theory calculations.     

Defect Engineering in Ambipolar Layered Materials for Mode-Regulable Nociceptor

Defect engineering represents a significant approach for atomically thick 2D semiconductor material development to explore the unique material properties and functions. Doping-induced conversion of conductive polarity is particularly beneficial for optimizing the integration of layered electronics. Here, controllable doping behavior in palladium diselenide (PdSe₂) transistor is demonstrated by manipulating its adatom-vacancy groups. The underlying mechanisms, which originate from reversible adsorption/desorption of oxygen clusters near selenide vacancy defects, are investigated systematically via their dynamic charge transfer characteristics and scanning tunneling microscope analysis. The modulated doping effect allows the PdSe₂ transistor to emulate the essential characteristics of photo nociceptor on a device level, including firing signal threshold and sensitization. Interestingly, electrostatic gating, acting as a neuromodulator, can regulate the adaptive modes in nociceptor to improve its adaptability and perceptibility to handle different danger levels. An integrated artificial nociceptor array is also designed to execute unique image processing functions, which suggests a new perspective for extension of the promise of defect engineered 2D electronics in simplified sensory systems toward use in advanced humanoid robots and artificial visual sensors.     

IEEE802.15.4协议的性能分析与仿真

IEEE 802.15.4是一个自组织的无线网络标准,其中制定了PHY层和MAC层规范,主要应用场合为低成本、低功耗、低复杂度的无线个域网.许多参数在IEEE 802.15.4标准中仅给出取值范围而并未给出确定的值,虽然这些值对系统性能有着较为显著的影响.个域网中的设备大量采用电池供电,因此实现更低的能量消耗是该网络标...     

TiO2/MXene-Assisted LDI-MS for Urine Metabolic Profiling in Urinary Disease

Cancer remains an intractable medical problem. Rapid diagnosis and identification of cancer are critical to differentiate it from nonmalignant diseases. High-throughput biofluid metabolic analysis has potential for cancer diagnosis. Nevertheless, the present metabolite analysis method does not meet the demand for high-throughput screening of diseases. Herein, a high-throughput, cost-effective, and noninvasive urine metabolic profiling method based on TiO₂/MXene-assisted laser desorption/ionization mass spectrometry (LDI-MS) is presented for the efficient screening of bladder cancer (BC) and nonmalignant urinary disease. Combined with machine learning, TiO₂/MXene-assisted LDI-MS enables high diagnostic accuracy (96.8%) for the classification of patient groups (including 47 BC and 46 ureteral calculus (UC) patients) from healthy controls (113 cases). In addition, BC patients can also be identified from noncancerous UC individuals with an accuracy of 88.3% in the independent test cohort. Furthermore, metabolite variations between BC and UC individuals are investigated based on relative quantification, and related pathways are also discussed. These results suggest that this method, based on urine metabolic patterns, provides a potential tool for rapidly distinguishing urinary diseases and it may pave the way for precision medicine.     

Performance analysis of next generation web access via satellite

Responsiveness is a critical metric for web performance. Recent work in the Internet Engineering Task Force (IETF) and World Wide Web Consortium (W3C) has resulted in a new set of web protocols, including definition of the hypertext transfer protocol version 2 (HTTP/2) and a corresponding set of TCP updates. Together, these have been designed to reduce the web page download latency compared with HTTP/1.1. This paper describes the main features of the new protocols and discusses the impact of path delay on their expected performance. It then presents a set of tests to evaluate whether current implementations of the new protocols can offer benefit with an operational satellite access network and suggests how the specifications can evolve and be tuned to further enhance performance for long network paths. Copyright © 2016 John Wiley & Sons, Ltd.