Stackable nonvolatile memory with ultra thin polysilicon film and low-leakage (Ti, Dy)xOy for low processing temperature and low operating voltages

We report the fabrication process as well as material and electrical characterization of ultra thin body (UTB) thin film transistors (TFTs) for stackable nonvolatile memories by using in situ phosphorous doped low-temperature polysilicon followed by the chemical mechanical polishing (CMP) process. The resulting polysilicon film is about 13 nm thick with approximately 10¹⁹ cm⁻³ doping. Root mean square surface roughness below 1 nm is achieved. Metal nanocrystals and high-k dielectric are selected for storage nodes and tunneling barriers to achieve low operating voltages. The number density and average diameter of nanocrystals embedded in the gate stack are 7.5 × 10¹¹ cm⁻² and 5.8 nm, respectively. Furthermore, scanning transmission electron microscopy (STEM), convergent beam electron diffraction (CBED) and electron energy loss spectroscopy (EELS) are performed for material characterization. The dielectric constant of the (Ti, Dy)_xO_y film is 35, and the off-state leakage current at −1 V bias and 2.8 nm equivalent oxide thickness is 5 × 10⁻⁷ A/cm². We obtain a memory window of about 0.95 V with ±6 V program/erase voltages. Our results show that UTB TFT is a promising candidate for the three-dimensional integration in high-density nonvolatile memory applications.     

Use of Mesoscopic Host Matrix to Induce Ferrimagnetism in Antiferromagnetic Spinel Oxide

Despite the advances in the methods for fabricating nanoscale materials, critical issues remain, such as the difficulties encountered in anchoring, and the deterioration in their stability after integration with other components. These issues need to be addressed to further increase the scope of their applicability. In this study, using epitaxial mesoscopic host matrices, materials are spatially confined at the nanoscale, and are supported, anchored, and stabilized. They also exhibit properties distinct from the bulk counterparts proving their high quality nanoscale nature. ZnFe₂O₄ and SrTiO₃ are used as the model confined material and host matrix, respectively. The ZnFe₂O₄ phases are spatially confined by the SrTiO₃ mesoscopic matrix and have strongly enhanced ferrimagnetic properties as compared to bulk and plain thin films of ZnFe₂O₄, with a Curie temperature of ≈500 K. The results of a series of control experiments and characterization measurements indicate that cationic inversion, which originates from the high interface‐to‐volume ratio of the ZnFe₂O₄ phase in the ZnFe₂O₄–SrTiO₃ nanocomposite film, is responsible for the magnetization enhancement. An exchange bias is observed, owing to the coexistence of ferrimagnetic and antiferromagnetic regions in the confined ZnFe₂O₄ phase. The magnetic properties are dependent on the ZnFe₂O₄ crystallite size, which can be controlled by the growth conditions.     

阐释Sigma与机器性能的关系

生产设备的Sigma或Cpk等级非常重要,但其背后的理论很易会引起混淆.统计工艺控制(SPC)工具可以算出答案,但是假如设备一直达不到制造商声称的性能,那又如何?一些设备供应商甚至对于机器什么时候能达到最理想的重复精度6-Sigma的意见也不一致,当中的不稳定性主要来自如何诠释数据及如何运用适当的变数上限和下限.其实关键在于工艺的标准偏差,这是大家都同意的一点.     

下一代显示接口新标准--DisplayPort

随着显示技术逐渐转移到高性能的平板以及微电子技术,业界需要一种可扩充、开放产业标准的数字接口,以及可以把功能升级的解决方案。这种可升级的显示接口,应能满足企业以及一般消费者的各种需求。DisplayPort就是这种下一代的显示接口,可以为PC、监视器、显示面板、投影仪、以     

Level Set Hyperspectral Image Classification Using Best Band Analysis

We present a supervised hyperspectral classification procedure consisting of an initial distance-based segmentation method that uses best band analysis (BBA), followed by a level set enhancement that forces localized region homogeneity. The proposed method is tested on two hyperspectral images of an urban and rural nature. The proposed method is compared to the maximum likelihood (ML) method using BBA. Quantitative results are compared using segmentation and classification accuracies. Results show that both the initial classification using BBA features and the level set enhancement produced high-quality ground cover maps and outperformed the ML method, as well as previous studies by the authors. For example, with the compact airborne spectrographic imager image, the ML method resulted in accuracies les95.5%, whereas the level set segmentation approach resulted in accuracies as high as 99.7%.     

Modeling of spiking analog neural circuits using organic semiconductor thin film transistors with silicon oxide nitride semiconductor gates

This paper uses the results of the characterization of amorphous semiconductor thin film transistors (TFTs) with the quasi-permanent memory structure referred to as silicon oxide nitride semiconductor (SONOS) gates, to model spiking neural circuits. SONOS gates were fabricated and characterized. In addition, MOSFETs using organic copper phthalocyanine (CuPc) were fabricated with these SONOS gates to demonstrate proof of concept performance. Analog spiking circuits were then modeled using these low performance TFTs to demonstrate the general suitability of organic TFTs in neural circuits. The basic circuit utilizes a standard comparator with charge and discharge circuits. A simple Hebbian learning circuit was added to charge and discharge the SONOS device. The use of these elements allows for the design and fabrication of high-density 3-dimensional circuits that can achieve the interconnect density of biological neural systems.     

开关增益运算放大器作为检相器或混频器

一些运算放大器．比如Analog Devices公司的AD8041和Intersil公司的EL5100,提供禁用引脚．它使人们能把数个运算放大器的输出并联用于视频多路传输。除了这种多路传输以外．人们还能用这种禁用功能把运算放大器配置作为检相器或混频器。图1描绘了禁用功能如何实现低频检相器。人们可以按相位参考信号的速率来开关该电路的放大器的增益。     

Model-based automated extraction of microtubules from electron tomography volume.

We propose a model-based automated approach to extracting microtubules from noisy electron tomography volume. Our approach consists of volume enhancement, microtubule localization, and boundary segmentation to exploit the unique geometric and photometric properties of microtubules. The enhancement starts with an anisotropic invariant wavelet transform to enhance the microtubules globally, followed by a three-dimensional (3-D) tube-enhancing filter based on Weingarten matrix to further accentuate the tubular structures locally. The enhancement ends with a modified coherence-enhancing diffusion to complete the interruptions along the microtubules. The microtubules are then localized with a centerline extraction algorithm adapted for tubular objects. To perform segmentation, we novelly modify and extend active shape model method. We first use 3-D local surface enhancement to characterize the microtubule boundary and improve shape searching by relating the boundary strength with the weight matrix of the searching error. We then integrate the active shape model with Kalman filtering to utilize the longitudinal smoothness along the microtubules. The segmentation improved in this way is robust against missing boundaries and outliers that are often present in the tomography volume. Experimental results demonstrate that our automated method produces results close to those by manual process and uses only a fraction of the time of the latter.     

高可靠性RF技术服务于无线和RFID市场

近几年,无论是手机代表的无线移动网络及其基础设施,还是以蓝牙(Bluetooth)、无线局域网(WLAN)、Zigbee等长、短距离的无线通信技术,或者是WiMax、RFID等面向特定应用的专门技术,给人们带来了种种方便,也在悄悄改变着产业的格局.作为各种无线技术基础的RF技术,也在不断吸纳新技术、新设计,以满足系统对于更大数据传输量、更低的功耗和成本要求、更苛刻的信号可靠性要求等挑战.从另一侧面看,由于RF技术固有的较高门坎,并非一些新手力所能及,虽然半导体产业链以厂商数量众多著称,但RF技术供应商则相对较少.