薄金板可靠性研究及金厚控制

针对沉金工艺的PCB板,研究了板面金厚分布的规律,.时研究了金厚0.03μm产品的可靠性,进而对金厚的0.03μm板的金厚通过统计控制方法计算设定控制限进行控制,已达到成本控制的目的.     

CH_4-CO_2二元系低温分离方案的可行性探讨

通过对CH4-CO2二元系进行相图分析,得出低温分离脱除CO2的两种方案,一是气液分离,一是气固分离。采用闪蒸分离的方法来研究气液分离方案的可行性,利用HYSYS软件对二元系进行了闪蒸分离的计算分析,结果表明闪蒸分离难以同时保证较高的甲烷回收率和甲烷纯度,从而证明了气液分离方案不可行。根据气固相平衡计算得出了CH4-CO2二元系中CO2的结霜温度图,据图分析了气固分离方法的可行性,结果表明凝华分离方案可以达到带压液化天然气流程的要求,因而是可行的。     

中低分辨率CMOS闪烁型模数转换器的折中考虑与设计

对中低分辨率CMOS闪烁型模数转换器的四个主要模块的折中设计进行了研究.这些折中考虑包括基准电压的非理想因素、前置放大器的折中六边形思考、再生比较器的滞回作用、误差更正电路.在模块折中设计研究的基础上,CMOS闪烁型模数转换器可达到高性能和低功耗.根据这种设计考虑,采用TSMC 0.25 μm CMOS 单层多晶硅五层金属工艺实现了一个4 bit 65 MHz的高转换率的闪烁型模数转换器.     

Calamitic Blatter Radicals for Large-Area Solution-Coated Resistive Memories

Radical molecules exhibit fast redox kinetics, are widely explored for data processing and energy storage. However, the insulating aliphatic matrix isolates the radical units, thus resulting in a weak charge transporting ability. Herein, calamitic Blatter radicals (CBR) with highly conductive [1]benzothieno[3,2-b]benzothiophene (BTBT) as the conjugated backbone are designed and synthesized. It is found that bistable redox character associated with large conjugated backbone allows these Blatter radical derivatives to be switched with ON/OFF ratio reaching 10⁶ and retention time exceeding 10⁴ s in solution processed devices. In addition, these radicals are unveiled to perform tunable, multi-mode field-responsive resistance behaviors, including write-once-read-many (WORM), FLASH, and dynamic random access memory (DRAM), by molecular engineering strategy. This finding provides fundamental understanding for charge transferring dynamics and redox-switching mechanism of radical molecules with respect to electronic applications.     

The Opportunity of Negative Capacitance Behavior in Flash Memory for High-Density and Energy-Efficient In-Memory Computing Applications

Flash memory is a promising candidate for use in in-memory computing (IMC) owing to its multistate operations, high on/off ratio, non-volatility, and the maturity of device technologies. However, its high operation voltage, slow operation speed, and string array structure severely degrade the energy efficiency of IMC. To address these challenges, a novel negative capacitance-flash (NC-flash) memory-based IMC architecture is proposed. To stabilize and utilize the negative capacitance (NC) effect, a HfO₂-based reversible single-domain ferroelectric (RSFE) layer is developed by coupling the flexoelectric and surface effects, which generates a large internal field and surface polarization pinning. Furthermore, NC-flash memory is demonstrated for the first time by introducing a RSFE and dielectric heterostructure layer in which the NC effect is stabilized as a blocking layer. Consequently, an energy-efficient and high-throughput IMC is successfully demonstrated using an AND flash-like cell arrangement and source-follower/charge-sharing vector-matrix multiplication operation on a high-performance NC-flash memory.     

Highly Enhanced Polarization Switching Speed in HfO2-based Ferroelectric Thin Films via a Composition Gradient Strategy

The next-generation semiconductor memories are essentially required for the advancements in modern electronic devices. Ferroelectric memories by HfO₂-based ferroelectric thin films (FE-HfO₂) have opened promising directions in recent years. Nevertheless, improving the polarization switching speed of FE-HfO₂ remains a critical task. In this study, it is demonstrated that the composition-graded Hf_1-xZr_xO₂ (HZO) ferroelectric thin film has more than two times faster polarization switching speed than the conventional composition-uniform one. Meanwhile, it has excellent ferroelectricity and improved endurance characteristics. It is also discovered that when the HZO thin film has a gradient composition, the polarization-switching dynamics shifts from the nucleation-limited-switching mechanism to the domain-wall growth mechanism. Moreover, the transition of switching dynamics is responsible for the faster speed and better endurance of the composition-graded HZO thin film. These findings not only reveal the physical mechanisms of this material system but also provide a new strategy for memory devices having faster speed and higher endurance.     

Multiphase Polarization in Ion-Intercalation Nanofilms: General Theory Including Various Surface Effects and Memory Applications

Ion concentration polarization (CP, current-induced concentration gradient adjacent to a charge-selective interface) has been well studied for single-phase mixed conductors (e.g., liquid electrolyte), but multiphase CP has been rarely addressed in literature. In our recent publication, we proposed that CP above certain threshold currents can flip the phase distribution in multiphase ion-intercalation nanofilms sandwiched by ion-blocking electrodes. This phenomenon is known as multiphase polarization (MP). It is then proposed that MP can further lead to nonvolatile interfacial resistive switching (RS) for asymmetric electrodes with ion-modulated electron transfer, which theory can reproduce the experimental results of LTO memristors. In this study, a comprehensive 2D phase-field model is derived for coupled ion-electron transport in ion-intercalation materials, with surface effects including electron transfer kinetics, non-neutral wetting, energy relaxation, and surface charge. Then, the model is used to study MP. Time evolution of phase boundaries is presented, and analyze the switching time, current, energy, and cyclic voltammetry, for various boundary conditions. It is found that the switching performance can be improved significantly by manipulating surface conditions and mean concentration. Finally, the prospects of MP-based memories and possible extensions of the current model is discussed.     

Flash存储器技术与发展

Flash存储器是在20世纪80年代末逐渐发展起来的一种新型半导体不挥发性存储器，它具有结构简单、高密度、低成本、高可靠性和系统的电可擦除性等优点，是当今半导体存储器市场中发展最为迅速的一种存储器。文章对Flash存储器的发展历史和工作机理、单元结构与阵列结构、可靠性、世界发展的现状和未来趋势等进行了深入的探讨。