硅晶片化学机械抛光中的化学作用机理

通过分析硅晶片化学机械抛光过程中软质层的形成及其对材料去除过程的影响,研究了使用纳米CeO2磨料进行化学机械抛光中的化学作用机理.分析表明,软质层是抛光液与硅晶片反应形成的一层覆盖在硅基体表面的腐蚀层,其硬度比基材小,厚度大约在几个纳米.软质层的存在一方面增大单个磨料所去除材料的体积,增加材料去除速率;另一方面减小了磨料嵌入硅晶片基体的深度,这对于实现塑性磨削,降低抛光表面粗糙度,都起着重要的作用.     

铝薄膜CMP影响因素分析

提出了在碱性抛光液中铝薄膜化学机械抛光的机理模型,对抛光液的pH值、磨料、氧化剂浓度对过程参数的影响做了一些试验分析。试验结果表面粗糙度的铝薄膜所需的最优化CMP过程参数:硅溶胶粒径为15～20nm,pH值为10.8～11.2,氧化剂浓度为2.5%～3%。     

基于锗硅异质纳米晶的非易失浮栅存储器的存储特性

利用自组织生长和选择化学刻蚀方法在超薄SiO2隧穿氧化层上制备了渐变锗硅异质纳米晶,并通过电容.电压特性和电容-时间特性研究了该纳米结构浮栅存储器的存储特性.测试结果表明,该异质纳米晶非易失浮栅存储器具有良好的空穴存储特性,这是由于渐变锗硅异质纳米晶中Ge的价带高于Si的价带形成了复合势垒,空穴有效地存储在复合势垒的Ge的一侧.     

界面化学反应形成的纳米颗粒对有机交叉点存储器的影响

研究了有机交叉点存储器件中,有机物与电极界面化学反应形成的纳米颗粒对电学特征的影响.器件的阳极和阴极分别为氧化铟锡(ITO)导电玻璃和真空热蒸发沉积的～薄膜,有机半导体层为真空热蒸发沉积的2-amino-4,5-dicyanoimidazole(AlDcN)薄膜.通过透射电子显微镜(TEM)和X光电子能谱(XPS)测量,在AIDCN/ITO界面上发现SnOx纳米颗粒形成,并证明此纳米颗粒的形成是由于ITO中的高价氧化锡和AIDCN之间的固相反应,纳米颗粒中的Sn元素主要是从ITO表面的锡富集层中析出.研究证明了界面上纳米颗粒的形成是器件双稳态现象的关键,用这种方式制成的交叉点结构的三层有机存储器件其开关比达到107～1011.     

基于ZnO纳米线阵列和P3HT的混合光电二极管特性

为了发展低成本、大面积和高性能光电二极管,采用简单的化学浴沉积方法,在氧化铟锡(I TO) 玻璃基底上生长良好取向的ZnO纳米线阵列(ZNWA),然后在生长的ZNWA上旋涂规整的聚3-己 基噻吩(P3HT)层,形成结构为ITO/ZNWA/P3HT/Ag的光电二极管。系统研究了此光电二极管在 暗态和在太阳模拟器的光照下的电流-电压 (I-V)特性。实验结果表明,器件在暗态和光照下都表现出良好 的二极管特性。暗态下,在偏压±2V处的整流 率为3211, 理想因子为1.8、低开启电压为0.5V和反偏饱和电流为1．13×10－7 A。在20mW/cm²光照下,在偏压±2V处的整流率为39.1、开启电压为0.3V。器件中产生了大量的光生载流子,根据器件的能级结构图和光生载流子的 输运过程对此光电二极管的光响应机理进行了解释。     

Electrocatalysis of Fe-N-C Bonds Driving Reliable Interphase and Fast Kinetics for Phosphorus Anode in Sodium-Ion Batteries

Phosphorus exhibits high capacity and low redox potential, making it a promising anode material for future sodium-ion batteries. However, its practical applications are confined by poor durability and sluggish kinetics. Herein, an innovative in-situ electrochemically self-driven strategy is presented to embed phosphorus nanocrystal (≈10 nm) into a Fe-N-C-rich 3D carbon framework (P/Fe-N-C). This strategy enables rapid and high-capacity sodium ion storage. Through a combination of experimental assistance and theoretical calculations, a novel synergistic catalytic mechanism of Fe-N-C is reasonably proposed. In detail, the electrochemical formation of Fe-N-C catalytic sites facilitates the release of fluorine in ester-based electrolyte, inducing Na⁺-conducting-enhanced solid-electrolyte interphase. Furthermore, it also effectively induces the dissociation energy of the P-P bond and promotes the reaction kinetics of P anode. As a result, the unconventional P/Fe-N-C anode demonstrates outstanding rate-capability (267 mAh g⁻¹ at 100 A g⁻¹) and cycling stability (72%, 10 000 cycles). Notably, the assembled pouch cell achieves high-energy density of 220 Wh kg⁻¹.     

基于化学机械动力学的碱性铜抛光液平坦化机理研究

The planarization mechanism of alkaline copper slurry is studied in the chemical mechanical polishing (CMP) process from the perspective of chemical mechanical kinetics.Different from the international dominant acidic copper slurry,the copper slurry used in this research adopted the way of alkaline technology based on complexation. According to the passivation property of copper in alkaline conditions,the protection of copper film at the concave position on a copper pattern wafer surface can be achieved without the corrosion inhibitors such as benzotriazole(BTA),by which the problems caused by BTA can be avoided.Through the experiments and theories research,the chemical mechanical kinetics theory of copper removal in alkaline CMP conditions was proposed. Based on the chemical mechanical kinetics theory,the planarization mechanism of alkaline copper slurry was established. In alkaline CMP conditions,the complexation reaction between chelating agent and copper ions needs to break through the reaction barrier.The kinetic energy at the concave position should be lower than the complexation reaction barrier,which is the key to achieve planarization.     

AlN成核层厚度对Si上外延GaN的影响

采用低温AlN成核层,在Si(111)衬底上,用金属有机化学气相沉积(MOCVD)法生长了GaN薄膜。采用高分辨X射线衍射(XRD)、椭圆偏振光谱仪和原子力显微镜(AFM)研究了AlN成核层的厚度对GaN外延层的影响。对AlN的测试表明,AlN的表面粗糙度(RMS)随着厚度增加而变大。对GaN的测试表明,所有GaN样品在垂直方向处于压应变状态,并且随AlN厚度增加而略有减弱。GaN的(0002)_ω扫描的峰值半宽(FWHM)随着AlN成核层厚度增加而略有升高,GaN(10-12)_ω扫描的FWHM随着厚度增加而有所下降。(10-12)_ω扫描的FWHM与GaN的刃型穿透位错密度相关,A1N成核层的厚度较大时会降低刃型穿透位错密度,并减弱c轴方向的压应变状态。     

一种可用于化学传感的对角对称光子晶体光纤设计

本文提出了一种可用于化学传感的具有高双折射、低损耗的光子晶体光纤,并系统地分析了空气孔参数对光纤光学特性的影响.研究表明,最优结构的光纤在典型波长1.55μm时对水、乙醇和苯的相对灵敏度分别可达56.3％、59.9％和62.5％,相比现有光子晶体光纤分别提高1.05～6.25倍、1.05～4.99倍和1.03～4.63...     

氟气-清洗化学气相沉积反应器腔室的创新方式

对于将氟气应用在化学气相沉积器清洗的应用而言,其安全性、稳定性、纯度和价格,在应用上是一个新的挑战.对一般气相沉积反应器清洗而言,一体化氟气供应策略,对寻求低价取代方案的使用者而言,是最安全和稳定的供应方式.