侧墙技术在相变存储器中的应用

从相变存储器(phase change random access memory,PCRAM)的基本结构和工作原理出发,首先介绍了PCRAM的技术优势、面临的技术挑战、常用的解决策略以及存在的相应问题;接着阐述了在微电子加工中广泛应用的关键工艺——侧墙技术,并将其在PCRAM中的应用成果进行了分类;然后从加热电极的制备、相变材料限制结构的制备、新相变材料的制备与表征和器件间互联等4个方面展开叙述;最后展望了该技术在相变存储领域应用发展的趋势。侧墙技术因其具备自对准的特点,制备工艺可控性好,制备精度不依赖于光刻精度,在纳米技术飞速发展的今天,侧墙技术将会在更高精度上发挥其作用。     

世界种子公司概述

世界目前每年的种子市场份额近２００亿美元。种子产业的业务范围一般分为大田作物种子，园艺作物种子（蔬菜与花卉），牧草作物种子等几类。种子产业按其发展和特点又可分为几种类型，第一类以美国先锋国际良种公司（ＰｉｏｎｅｅｒＨｉ－ＢｒｅｄＩｎｔｅｒｎａｔｉｏｎ...     

大面积非光刻纳米电极间隙的制备

A lithography-independent and wafer scale method to fabricate a metal nanogap structure is demonstrated. Polysilicon was first dry etched using photoresist （PR） as the etch mask patterned by photolithography. Then, by depositing conformal SiO2 on the polysilicon pattern, etching back SiO2 anisotropically in the perpendicular direction and removing the polysilicon with KOH, a sacrificial SiO2 spacer was obtained. Finally, after metal evaporation and lifting-off of the SiO2 spacer, an 82 nm metal-gap structure was achieved. The size of the nanogap is not determined by the photolithography, but by the thickness of the SiO2. The method reported in this paper is compatible with modern semiconductor technology and can be used in mass production.     

Simple and low-cost fabrication of a metal nanoplug on various substrates by electroless deposition

An electroless deposition(ELD) method is introduced to fabricate a metal nanoplug for its advantages of simplicity,low cost and auto-selectivity.It was demonstrated that nanoplugs of less than 50 nm in diameter can be fabricated by ELD nickel on various substrates,such as silicon,tungsten and titanium nitride.The main composition of the ELD nanoplug was characterized as nickel by an energy dispersive X-ray microanalyzer.A functional vertical phase-change random access memory(PCRAM) device with a heater diameter of around 9μm was fabricated by using the ELD method.TheⅠ-Ⅴcharacteristics demonstrated that the threshold current is only 90.8μA.This showed that the ELD process can satisfy the demands of PCRAM device application,as well as device performance improvement.The ELD process provides a promising method for the simple and low-cost fabrication of metal nanoplugs.     

一种新型建筑节能产品——低辐射镀膜玻璃

建筑节能工程是国家公布的“十一五”十大重点节能工程之一,它要求新建建筑全面严格执行节能50％的标准,四个直辖市和北方严寒、寒冷地区实施新建建筑节能65％的标准。建筑节能是一项复杂的系统工程,由多个子系统构成,包括墙体、地面、采暖制冷、健康通风和门窗。在门窗子系统中,对配套玻璃提出了新的要求,低辐射镀膜玻璃就是一种满足建筑节能需求的新产品。目前,该产品已经在山东临沂农村抗震节能生态住宅示点工程中使用。     

浸没式膜生物反应器处理啤酒废水

采用浸没式膜生物反应器(MBR)处理模拟啤酒废水.考察了活性污泥的驯化过程,同时考察了不同水力停留时间(HRT)下膜生物反应器对啤酒废水的去除效果及稳定性,确定最佳的水力停留时间(HRT)为10 h.在此条件下,当进水CODCr在732.5～1 544 mg/L时,CODCr的平均去除率达97.02%;进水NH3-N在25.65～41.41 mg/L时,的平均去除率为84.69%.实验结果表明,MBR工艺具有很强的耐冲击负荷能力,采用MBR工艺处理啤酒废水技术可行,实验结果可为工业规模应用提供技术参考.     

用化学镀方法在不同衬底上制备纳米尺度金属插塞电极的研究

纳米尺度金属插塞电极在现代纳米电子学中有很重要的应用价值。本文研究了用化学镀方法制备纳米尺度金属插塞电极,具有简单、低成本和自选择性的优点。化学镀甚至可以分别在硅衬底、钨衬底和氮化钛衬底上制备出直径小于50纳米的镍插塞电极。用能量色散X射线微量分析仪（EDXM）测定出用化学镀在硅衬底上制备出的纳米尺度插塞电极的主要成分是镍。最后,采用化学镀方法,制备了直径为9微米的插塞电极的垂直结构相变存储器器件。通过研究器件的电流-电压特性表明,化学镀方法可以满足器件应用要求。因此,用简单、低成本的化学镀方法来制备纳米尺度金属插塞电极,对器件的应用有重要意义。