生长气体流量对SiC单晶缺陷的影响

实现了熔融KOH进行SiC体单晶择优腐蚀估测缺陷密度的方法.本文报道了采用该技术对体SiC单晶缺陷密度估测的结果.腐蚀会在Si面形成六边形腐蚀坑,在C面形成圆形腐蚀坑.腐蚀速率和蚀坑形状与SiC生长工艺有关.对在高生长气流量下用PVT工艺制备的SiC样品,其刃位错、螺位错与微管密度分别为2.82×105,94和38cm-2;对在低生长气流量下用PVT工艺制备的SiC样品,其上述缺陷密度分别为9.34×105,2和29cm-2.结果表明:随着生长气体流量的增加,由于避免了N2掺杂,刃位错密度下降.     

高坝施工导流洞改为永久竖井泄洪洞水力学研究

本文通过模型试验研究涡室－竖井内消能系统，用内设阻涡坎的涡室连接泄洪洞和竖井，带盲洞的消力并连接竖井和导流洞。探讨了涡室－竖井内消能系统中的流态、边壁时均压力、脉动压力、消能率、消力井尺寸与消能率之间的关系和消能机制等水力学问题。     

特征提取在近红外激光检测半导体内微缺陷中的应用

提出了利用近红外激光散射光强分布分析来检测半导体材料内部微体缺陷的检测方法.在研究广义洛仑兹-米氏理论(Generalized Lorenz-Mie Theory)的基础上,通过对理论上散射光强分布的分析,近红外激光散射光强分布空间FFT的截止频率被提取为判定半导体材料缺陷大小的判据,依据这一判据,可以快速的判定微体缺陷的大小.并通过对GaAs样品进行了实验研究,证明了该方法和判据的有效性.     

开路缺陷的软故障关键面积研究

从软故障的产生机制出发,研究了软故障的作用模式.为了计算软     

Composition Engineering of All‐Inorganic Perovskite Film for Efficient and Operationally Stable Solar Cells

Cesium‐based inorganic perovskites have recently attracted great research focus due to their excellent optoelectronic properties and thermal stability. However, the operational instability of all‐inorganic perovskites is still a main hindrance for the commercialization. Herein, a facile approach is reported to simultaneously enhance both the efficiency and long‐term stability for all‐inorganic CsPbI_2.5Br_0.5 perovskite solar cells via inducing excess lead iodide (PbI₂) into the precursors. Comprehensive film and device characterizations are conducted to study the influences of excess PbI₂ on the crystal quality, passivation effect, charge dynamics, and photovoltaic performance. It is found that excess PbI₂ improves the crystallization process, producing high‐quality CsPbI_2.5Br_0.5 films with enlarged grain sizes, enhanced crystal orientation, and unchanged phase composition. The residual PbI₂ at the grain boundaries also provides a passivation effect, which improves the optoelectronic properties and charge collection property in optimized devices, leading to a power conversion efficiency up to 17.1% with a high open‐circuit voltage of 1.25 V. More importantly, a remarkable long‐term operational stability is also achieved for the optimized CsPbI_2.5Br_0.5 solar cells, with less than 24% degradation drop at the maximum power point under continuous illumination for 420 h.     

Defect Passivation in Perovskite Solar Cells by Cyano‐Based π‐Conjugated Molecules for Improved Performance and Stability

Defects at the surface and grain boundaries of metal–halide perovskite films lead to performance losses of perovskite solar cells (PSCs). Here, organic cyano‐based π‐conjugated molecules composed of indacenodithieno[3,2‐b]thiophene (IDTT) are reported and it is found that their cyano group can effectively passivate such defects. To achieve a homogeneous distribution, these molecules are dissolved in the antisolvent, used to initiate the perovskite crystallization. It is found that these molecules are self‐anchored at the grain boundaries due to their strong binding to undercoordinated Pb²⁺. On a device level, this passivation scheme enhances the charge separation and transport at the grain boundaries due to the well‐matched energetic levels between the passivant and the perovskite. Consequently, these benefits contribute directly to the achievement of power conversion efficiencies as high as 21.2%, as well as the improved environmental and thermal stability of the PSCs. The surface treatment provides a new strategy to simultaneously passivate defects and enhance charge extraction/transport at the device interface by manipulating the anchoring groups of the molecules.     

Signal noise perturbation on automotive mixed-mode semiconductor device generated by graded substrate defect

The semiconductor technologies evolution allows greatly reducing noise impact on products and many structures have been created to reduce its effect. However, this paper presents the apparition of a noise issue during the production of a mixed-mode device dedicated to automotive applications. The research investigations concerned the fact that failure was not detected at test level but at customer level; therefore, it was determinant to understand the root cause of this failure mode to drive corrective actions in order to secure customer. The challenge was to analyse noise in Failure Analysis (FA) without fault spatial localization results. Indeed, Light Emission Microscopy (EMMI) and Thermal Laser Stimulation (ex: Soft Defect Localization – SDL) were unable to provide any defective area in the product. The lack of failing device identification led us to combine electrical and design analyses in order to define hypothesis on the failure origin. It was then possible to drive physical investigations through different approaches, using physical cross-section, Secondary Ion Mass Spectrometry (SIMS) and Scanning Capacitance Microscopy (SCM) techniques. Finally, the obtained complementary results will be discussed and an explanation of the failure mechanism will be presented as the root cause issue, allowing defining the defective step in production process.     

C=0抽样方案在石英谐振器产品检验中的应用

基于质量管理体系的核心价值是以顾客为关注焦点,让顾客满意.只有为顾客提供满意的产品或服务,才能取得顾客长久的信任,保持对产品的忠诚.而实施“零缺陷”的管理和产品检验,就能将产品的质量风险降到最低,获得顾客满意,从而实现公司的经营目标.经对产品质量的分析,通过C=0的抽样方案、MIL-STD-1916抽样方案与GB/T2828.1-2003的抽样方案的实际使用和比较;突出C=0抽样方案在产品检验方面的优点;得出C=0抽样方案是目前在石英谐振器产品检验中值得推广采用的质量控制方案.     

旋转孔径频闪散斑干涉法用于缺陷检测

介绍了一种利用旋转孔径频闪散斑干涉法检测缺陷的新方法。该方法是一种非接触式的检测方法,不受缺陷形状和位置的影响,能够准确地检测出缺陷的大小和形状。分析了旋转孔径频闪散斑干涉法的基本原理,给出了散斑图全场滤波分析的平均光强解析式和实验结果。结果表明,该方法在一张散斑图上能记录物体动态变形的全过程,并能连续地再现出来,散斑图的信息量丰富;在实时滤波分析观察时,将滤波孔连续进行旋转,可观察到物体动态变形的全过程,散斑图的条纹在变化而缺陷的位置不变。     

硅片键合界面缺陷分布与Weibull模数的关系

从理论推导分析了键合片的缺陷分布与Weibull模数m之间的关系。此关系与实验相符,并利用此关系很好地解释了硅片键合强度随退火温度变化的关系。