光学元件的激光损伤阈值测量

激光损伤阈值的准确测量是研究高抗激光损伤光学元件的必要条件.分析了激光诱导损伤阈值的不确定度来源,包括激光能量测量、光斑有效面积测量、各能量密度处几率的计算以及对损伤几率点进行直线拟合4个方面.利用统计学原理和线性拟合等理论对不确定度分量及测试结果的相对合成不确定度进行了理论推导和计算.1 064 nm高反薄膜样品的实例分析表明,损伤阈值测量的相对合成不确定度为18.72%.     

光学元件的激光损伤阈值测试平台

建立了用于光学元件和材料的激光(1064 m与355 nm)损伤阈值测试平台.按照IsO-DIS 11254-1.2的测试规范,采用l-on-1打点与激光损伤几率的方法给出被测样品的激光损伤阈值.研制了激光光斑有效面积测试装置,提高了光学元件激光损伤阈值的测试精度.     

光学薄膜激光损伤阈值的智能检测研究

为了解决当前光学薄膜激光损伤阈值检测方法准确性差、可视化和灵活性不理想等难题,提出基于软件测试算法的光学薄膜激光损伤阈值检测方法。首先计算损伤阈值最终不确定度,并将不确定度计算结果代入损伤阈值检测中,然后利构成测量光路,激光在透镜上聚焦照射到待测样品上,根据测试软件程序对激光照射前后的图像进行预处理,判断是否存在损伤,若存在损伤,结合高斯光束理念获取有效光斑面积,最后损伤阈值,并进行了仿真实验,结果表明,该方法检测准确率和可视化程度高,且灵活性强。     

硅片背面减薄技术研究

硅片背面磨削减薄工艺中,机械磨削使硅片背面产生损伤,导致表面粗糙,且发生翘曲变形.分别采用粗磨、精磨、精磨后抛光和精磨后湿法腐蚀等四种不同背面减薄方法对15.24cm(6英寸)硅片进行了背面减薄,采用扫描电子显微镜对减薄后的硅片表面和截面形貌进行了表征,用原子力显微镜测试了硅片表面的粗糙度,用翘曲度测试仪测试了硅片的翘曲度.结果表明,经过粗磨与精磨后的硅片存在机械损伤,表面粗糙且翘曲度大,粗糙度分别为0.15和0.016 μm,翘曲度分别为147和109 μm;经过抛光和湿法腐蚀后的样品无表面损伤,粗糙度均小于0.01 μm,硅片翘曲度低于60 μm.     

预处理效应对1 064 nm 反射膜本征损伤性能的影响

激光预处理技术能够有效提升光学元件的激光损伤阈值。以1064nm 波长作用下的HfO2/SiO2高反射薄膜为研究对象,研究了单一能量密度梯度和多能量密度梯度的N-on-l、R-on-l和光栅扫描激光预处理技术对薄膜本征损伤性能的影响,并采用1-on-1测量方法对不同预处理技术的预处理效果进行了对比分析。实验结果表明:1-on-1测量曲线中的损伤几率数据、拟合直线参数以及损伤阈值的相对不确定度能够比较全面地反映测量结果的重复性;N-on-1方式下多能量密度梯度的预处理效果要优于单一能量密度梯度,但多梯度之间以及单一梯度之间的效果差异并不明显;当薄膜的零几率损伤阈值难以继续提升时,继续增加能量密度梯度将仅能改善薄膜非零损伤几率的性能。     

K9玻璃激光损伤的组合测试实验

光学玻璃作为高功率激光器重要的光学元件,准确测量它的损伤阈值对系统性能研究有重要意义。本文采用同批次K9玻璃进行了激光损伤测试实验,分别采用等离子体闪光法、图像法以及光谱法测试样品损伤阈值,实验结果表明:单纯等离子体闪光法、图像法、光谱法都可能出现判别不准确情况,无法准确确定样品损伤阈值。采用光谱法和图像法组合测试方法能够更可靠地得到损伤阈值。得到的K9在1064 μm波长下损伤阈值结果为22.47 J/cm2。验证了组合测试方法的可靠性。     

基于高斯脉冲激光空间分辨测量光学元件表面激光损伤阈值研究

提出一种基于高斯脉冲激光空间分辨测量光学元件表面激光损伤阈值的方法。通过设定激光能量密度差对高斯光斑进行能量密度分区,统计并分析每个能量密度分区的能量密度以及损伤密度分布,设定一个零损伤密度所对应的激光能量密度作为所测样品的激光损伤阈值。同时利用国际标准1-on-1激光损伤阈值测试方法对同一样品进行激光损伤阈值测试,并将两种测试方法获得的损伤阈值进行了比较分析,证明基于高斯脉冲激光空间分辨的激光损伤阈值测试方法,解决了国际标准1-on-1激光损伤阈值测试中将高斯光斑内空间能量密度以及损伤点的不均匀分布等效地视作均匀分布所带来的问题。     

电子束蒸发制备HfO2/SiO2高反膜的1064 nm激光预处理效应

激光预处理是提高薄膜元件抗激光损伤阈值的重要手段.对电子束蒸发HfO2,SiO2块状材料镀制的基频高反膜进行了1-on-1和R-on-1阈值测试,比较分析ur两种测试情况下出现的典型损伤形貌.实验发现,R-on-1测试表现出明显的预处理效应,其所测抗激光损伤阈值是1-on-1测试的3倍;1-on-1测试下的典型损伤形貌是围绕平底小坑的等离子烧蚀损伤,R-on-1测试下的典型损伤形貌仅是表面等离子体烧蚀损伤;表面轮廓测试的结果表明两种损伤形貌的烧蚀区域中心都是凸起的.两种典犁损伤破坏形貌及其差异的研究说明吸收件缺陷是引起此样品损伤的主要诱因,预处理对吸收性缺陷的力学稳定作用是此样品抗激光损伤阈值提高的宏观原因.     

Ar+刻蚀对InGaAs, n-InP和p-InP表面损伤及消除

研究了Ar+刻蚀对InGaAs, n-InP和p-InP表面的损伤，并用湿法腐蚀后处理消除损伤. Ar+刻蚀后InGaAs表面均方根粗糙度较小，而n-InP和p-InP表面明显变粗糙. 刻蚀后InGaAs PL强度增加，而n-InP和p-InP PL强度都减小. 用XPS分析了未刻蚀、Ar+刻蚀和湿法腐蚀后处理三种情况下样品表面原子含量.刻蚀后InGaAs表面In和Ga含量明显增加，n-InP和p-InP表面有严重P缺失. 湿法腐蚀后，样品表面原子含量和未刻蚀前基本一致.     

用感应气体放电记录材料表面和涂层的激光损伤

引言研究固体材料的激光损伤时，特别注意损伤阈值时的记录。它的可靠性和精度对分析激光损伤机理有重大意义。使用方法的多样性由研究损伤的不同方面及其相互作用决定。由于光学材料表面和涂层的激光损伤阈值通常低于相应样品的体损阈值，其监察和测量是一个经常需要解决的问题。记录材料烧蚀初始阶段的方法在研究材料表面和涂层损伤中占有重要位置。这些方法的基础是质谱法［1］、测高温法［2］或压电测量法［3］。使用这些方法不仅能得到阈值方面的信息，还能得到损伤特性的其它信息，较全面地描述激光与材料表面的相互作用。然而在样品…     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.