面向对注氢硅片中微结构的影响

把不同面向的注氢硅片制成横截面样品,在高分辨率透射电子显微镜下进行观察,发现衬底面向对其中的微结构有明显的影响.首先表现为衬底中主要出现平行于正表面的氢致片状缺陷,即(10 0 )衬底中,主要出现平行于正表面的{ 10 0 }片状缺陷,而(111)衬底中出现的主要是平行于正表面的{ 111}片状缺陷.其原因是注入引起垂直正表面的张应变.另外,面向的影响还表现为,(10 0 )衬底中出现的{ 113}缺陷在(111)衬底中不出现.在(111)衬底中出现的晶格紊乱团和空洞在(10 0 )衬底中不出现.从而推测,{ 111}片状缺陷的形成不发射自间隙原子,而(10 0 )片状缺陷的形成将发射自     

面向对注氢硅片中微结构的影响

把不同面向的注氢硅片制成横截面样品,在高分辨率透射电子显微镜下进行观察,发现衬底面向对其中的微结构有明显的影响.首先表现为衬底中主要出现平行于正表面的氢致片状缺陷,即(100)衬底中,主要出现平行于正表面的{100}片状缺陷,而(111)衬底中出现的主要是平行于正表面的{111}片状缺陷.其原因是注入引起垂直正表面的张应变.另外,面向的影响还表现为,(100)衬底中出现的{113}缺陷在(111)衬底中不出现.在(111)衬底中出现的晶格紊乱团和空洞在(100)衬底中不出现.从而推测,{111}片状缺陷的形成不发射自间隙原子,而(100)片状缺陷的形成将发射自间隙原子.     

氢气退火对大直径直拉硅单晶中空洞型缺陷的影响

研究了氢退火对大直径直拉硅单晶中空洞型缺陷 (voids)的影响 .样品在 10 5 0～ 12 0 0℃范围进行氢退火 ,退火前后样品上的流水花样缺陷 (FPD)和晶体原生粒子 (COP)在腐蚀后分别用微分干涉光学显微镜和激光记数器进行观察 .实验结果表明在氢退火以后 ,FPD缺陷的密度随温度升高不变 ,而样品上的 COP密度大量减少 .分析可知 ,氢气退火仅仅消除了硅片表面的 voids,而对于硅片体内的 voids不产生影响 ,并在实验的基础上 ,讨论了氢退火消除 voids的机理 .     

线切割硅片表面探究

硅片的表面损伤层,关系到切割后破片率及面的形状等。通过对硅片表面分析,发现硅片表面呈蜂窝状,有大孔、小孔和微孔。硅片侧面边缘呈山峰山沟状,并伴随有裂纹,从外向里分为表面镶嵌层和缺陷应力层。通过对硅片表面损伤的形成机理研究,发现通过以下调整可以减小表面损伤和提高表面质量:一是减小切割时的晶体所受到的垂直压力;二是调整碳化硅的直径分布系数,圆度系数,堆积密度。     

氢气退火对大直径直拉硅单晶中空洞型缺陷的影响

研究了氢退火对大直径直拉硅单晶中空洞型缺陷(voids)的影响.样品在1050～1200℃范围进行氢退火,退火前后样品上的流水花样缺陷(FPD)和晶体原生粒子(COP)在腐蚀后分别用微分干涉光学显微镜和激光记数器进行观察.实验结果表明在氢退火以后,FPD缺陷的密度随温度升高不变,而样品上的COP密度大量减少.分析可知,氢气退火仅仅消除了硅片表面的voids,而对于硅片体内的voids不产生影响,并在实验的基础上,讨论了氢退火消除voids的机理.     

区熔硅近表面洁净区和体内微缺陷的形成

中子辐照区熔 (氢 )硅片经退火后在近表面形成洁净区 ,在硅片内部形成体内微缺陷 .微缺陷的形成与中子辐照造成的损伤及单晶硅内氢杂质的催化加速有关 ,还与后续退火条件有关 .第一步退火的温度对微缺陷的尺度有很大的影响 ,中低温要比高温所形成的微缺陷小 .在退火过程中微缺陷有一个生长过程 ,110 0℃退火 2 h微缺陷已达最大 .硅片表面的粗糙度影响表面洁净区的形成 ,洁净区出现在未抛光面 ,双面抛光硅片不会形成表面洁净区.     

氢气退火对大直径直拉硅单晶中空洞型缺陷的影响

研究了氢退火对大直径直拉硅单晶中空洞型缺陷(voids)的影响.样品在1050～1200℃范围进行氢退火,退火前后样品上的流水花样缺陷(FPD)和晶体原生粒子(COP)在腐蚀后分别用微分干涉光学显微镜和激光记数器进行观察.实验结果表明在氢退火以后,FPD缺陷的密度随温度升高不变,而样品上的COP密度大量减少.分析可知,氢气退火仅仅消除了硅片表面的voids,而对于硅片体内的voids不产生影响,并在实验的基础上,讨论了氢退火消除voids的机理.     

区熔硅近表面洁净区和体内微缺陷的形成

中子辐照区熔(氢)硅片经退火后在近表面形成洁净区,在硅片内部形成体内微缺陷.微缺陷的形成与中子辐照造成的损伤及单晶硅内氢杂质的催化加速有关,还与后续退火条件有关.第一步退火的温度对微缺陷的尺度有很大的影响,中低温要比高温所形成的微缺陷小.在退火过程中微缺陷有一个生长过程,1100℃退火2h微缺陷已达最大.硅片表面的粗糙度影响表面洁净区的形成,洁净区出现在未抛光面,双面抛光硅片不会形成表面洁净区.     

区熔硅近表面洁净区和体内微缺陷的形成

中子辐照区熔(氢)硅片经退火后在近表面形成洁净区,在硅片内部形成体内微缺陷.微缺陷的形成与中子辐照造成的损伤及单晶硅内氢杂质的催化加速有关,还与后续退火条件有关.第一步退火的温度对微缺陷的尺度有很大的影响,中低温要比高温所形成的微缺陷小.在退火过程中微缺陷有一个生长过程,1100℃退火2h微缺陷已达最大.硅片表面的粗糙度影响表面洁净区的形成,洁净区出现在未抛光面,双面抛光硅片不会形成表面洁净区.     

智能剥离工艺的热动力学模型

提出了注氢硅片表面借助键合氧化硅片进行剥离的热动力学模型,这种剥离现象是退火过程中氢离子注入区氢气泡横向增长的结果.氢气泡的增长速率依赖于氢复合体分解和氢分子扩散所需的激活能,氢气泡的半径是退火时间、退火温度和注氢剂量的函数.氢气泡的临界半径可根据Griffith能量平衡条件来获得.根据氢气泡增长的这一临界条件,获得了不同劈裂温度时所需的剥离时间.     

Efficient macromodeling of defect propagation/growth mechanisms inVLSI fabrication

Particulate contamination deposited on silicon wafers is typically the dominant reason for yield loss in VLSI manufacturing. The transformation of contaminating particles into defects and then electrical faults is a very complex process which depends on the defect location, size, material, and the underlying IC topography. An efficient defect macromodeling methodology based on the rigorous two-dimensional (2-D) topography simulator METROPOLE, has been developed to allow the prediction and correlation of the critical physical parameters (material, size, and location) of contamination in the manufacturing process to device defects. The results for a large number of defect samples simulated using the above approach were compared with the data gathered from the AMD-Sunnyvale fabline. A good match was obtained indicating the accuracy for our method of developing contamination to defect propagation/growth macromodels     

Electrical characterization of crystal defects and oxygen in czochralski silicon using a gate-controlled diode

Defect generation in Czochralski (CZ) silicon crystal during heat treatment and effect of the defects on generation currents, measured by gate controlled diodes, were investigated. Sample wafers were obtained from an as-grown CZ silicon ingot which has a wide range of oxygen concentration but keeps other characteristics nearly constant. In the diode fabrication process, a two-step heat treatment method was utilized to control defect generation. It was found that stacking faults and dislocation loops, whose densities depend on oxygen concentration, increase the reverse current of the diode and the reverse current increases caused by defects vary with heat treatment condition. The most noticeable result was that the reverse current is enhanced by increasing oxygen concentration, even if no defect is observed in the device active region because of low defect density induced by heat treatment or of denuded zone formation. This result suggests the existence of some kind of electrically active defect caused by oxygen atoms in the crystal. Surface generation current is independent of crystal quality and two-step heat treatment conditions.     

重掺杂直拉硅单晶氧沉淀及其诱生二次缺陷

研究了重掺杂直拉硅单晶中掺杂元素硼、磷、砷、锑对氧沉淀及其诱生二次缺陷行为的影响 .实验结果表明 :重掺p型 (硼 )硅片氧沉淀被促进 ,氧沉淀密度高但无诱生二次缺陷 ;重掺n型 (磷、砷、锑 )硅片氧沉淀受抑制 ,氧沉淀密度低却诱生出层错 ;不同掺杂元素及浓度对重掺n型硅片氧沉淀抑制程度不同 ,并对氧沉淀诱生层错的形态产生影响 .讨论了重掺硅单晶中掺杂元素影响氧沉淀及其诱生二次缺陷的机理 ,并利用掺杂元素 本征点缺陷作用模型和原子半径效应模型对实验结果进行了解释 .     

几何设计对球硅太阳电池性能影响的有限元仿真

基于COMSOL软件的光学模块和半导体模块,从球缺比例、直径、正电极接触面积三个几何设计方面对球硅电池进行了仿真分析;通过对比反向饱和电流密度和理想因子,发现球硅半径越小、球缺比例越小、正电极相对接触面积越大,电池的电学特性越好;分析了不同直径球硅电池的几何特征与其光电参数之间的关联性,发现其与传统平面硅太阳电池存在显著差异。研究结果可为制作高效率低成本柔性球硅太阳电池提供理论指导。     

Defect engineering in implantation technology of silicon light-emitting structures with dislocation-related luminescence

Results obtained in development of physical foundations of ion implantation technology for fabrication of silicon light-emitting structures (LESs) based on dislocation-related luminescence and intended for operation at wavelengths close to ∼1.6 μm are summarized. The development of the concept of defect engineering in the technology of semiconductor devices makes it possible to determine the fundamental aspects of the process of defect formation; reveal specific features of the emission spectra related to changes in the implantation conditions of Er, Dy, Ho, O, and Si ions and the subsequent annealing; and design light-emitting structures with a desirable spectrum of luminescent centers and extended structural defects. The technological conditions in which only a single type of extended structural defect (Frank loops, perfect prismatic loops, or pure edge dislocations) is introduced into the light-emitting layer are found, which enables analysis of the correlation between the concentration of extended defects of a certain type and the intensity of lines of the dislocation-related luminescence. The key role of intrinsic point lattice defects in the origination and transformation of extended structural defects and luminescent centers responsible for the dislocation-related luminescence is revealed. It is found that the efficiency of luminescence excitation from the so-called D1 centers, which are of particular interest for practical applications, varies by more than two orders of magnitude between structures fabricated using different technological procedures. High-efficiency silicon light-emitting diodes with room-temperature dislocation-related luminescence have been fabricated.     

Intra-Cell Defects Diagnosis

The diagnosis is the process of isolating possible sources of observed failures in a defective circuit. Today, manufacturing defects appear not only in the cell interconnection, but also inside the cell itself (intra-cell defect). State of the art diagnosis approaches can identify the defect location at gate level (i.e., one or more standard cells and/or inter-connections can be provided as possible defect location). Some approaches have been developed to target the intra-cell defects. In this paper, we propose an intra-cell diagnosis method based on the “Effect-Cause” paradigm aiming at locating the root cause of the observed failures inside a logic cell. It is based on the Critical Path Tracing (CPT) here applied at transistor level. The main characteristic of our approach is that it exploits the analysis of the faulty behavior induced by the actual defect. In other word, we locate the defect by simply analyzing the effect induced by the defect itself. The advantage is the fact that we are defect independent (i.e., we do not have to explicitly consider the type and the size of the defect). Moreover, since the complexity of a single cell in terms of transistor number is low, the proposed intra-cell diagnosis approach requires a negligible computational time. The efficiency of the proposed approach has been evaluated by means of experimental results carried out on both simulations-based and industrial silicon data case studies.     

P-Type Versus n-Type Silicon Wafers: Prospects for High-Efficiency Commercial Silicon Solar Cells

Chemical and crystallographic defects are a reality of solar-grade silicon wafers and industrial production processes. Long overlooked, phosphorus as a bulk dopant in silicon wafers is an excellent way to mitigate recombination associated with these defects. This paper details the connection between defect recombination and solar cell terminal characteristics for the specific case of unequal electron and hole lifetimes. It then looks at a detailed case study of the impact of diffusion-induced dislocations on the recombination statistics in n-type and p-type silicon wafers and the terminal characteristics of high-efficiency double-sided buried contact silicon solar cells made on both types of wafers. Several additional short case studies examine the recombination associated with other industrially relevant situations—process-induced dislocations, surface passivation, and unwanted contamination. For the defects studied here, n-type silicon wafers are more tolerant to chemical and crystallographic defects, and as such, they have exceptional potential as a wafer for high-efficiency commercial silicon solar cells.     

基于热电耦合激励的TSV三维封装内部缺陷识别方法研究

由于硅通孔互连(Through Silicon Via,TSV)三维封装内部缺陷深藏于器件及封装内部,采用常规方法很难检测.然而TSV三维封装缺陷在热-电激励的情况下可表现出规则性的外在特征,因此可以通过识别这些外在特征达到对TSV三维封装内部缺陷进行检测的目的 .文章利用理论与有限元仿真相结合,对比了正常TSV与典型缺陷TSV的温度分布,发现了可供缺陷识别的显著差异.分析结果表明,在三种典型缺陷中,含缝隙TSV与正常TSV温度分布差异最小;其次为底部空洞TSV,差异最大的为填充缺失TSV.由此可知,通过检测热-电耦合激励下的TSV封装外部温度特征,可实现TSV三维封装互连结构内部缺陷诊断与定位.     

硅单晶片中的氧及对后续缺陷的影响

通过测量硅晶棒不同部位的氧含量,分析了氧在硅晶棒中的分布规律。结合高温氧化后的缺陷观察结果,研究了氧含量及后续高温生产工艺对硅晶体中缺陷数量的影响。对不同氧含量的两种硅单晶片所生产的功率集成电路进行了失效分析。结果表明,硅单晶片中的氧含量对产品成品率具有重要影响。当氧含量在1.77×10¹⁸~1.87×10¹⁸atoms/cm³及以上时,硅单晶片边缘出现明显的位错排,断面存在大量层错和位错缺陷,部分缺陷进入外延层中的晶体管,造成该处晶体管结漏电。相反,当氧含量偏低时,硅单晶片内的缺陷较少且分布不均,使得硅单晶片受到金属污染时不能有效吸杂而产生失效。     

硅中缺陷的透射电镜观察

随着集成电路制造工艺技术的不断进步,器件线宽不断减小,硅材料中缺陷的危害越来越不可忽视.通过TEM观察了硅中氧沉积、工艺诱生缺陷等并对之进行了分析.