无掩模激光干涉光刻技术研究

介绍了一种不用掩模的光刻技术———激光干涉光刻技术的基本原理,给出了干涉光刻技术的主要特点及一些可能的应用,并对实验系统和初步实验结果进行了分析。研究表明,激光干涉光刻具有大视场和分辨率高和视场宽等优点。     

激光分子束外延制备氧化物薄膜研究

激光分子束外延（LaserMBE）集PLD方法的制膜特点和传统MBE的超高真空精确控制原子尺度外延生长的原位实时监控为一体，不仅可以生长通常的半导体超晶格材料，尤其适于制备多元素、高熔点、复杂层次结构，如超导体、光学晶体、铁电体、田电体、铁磁体以及有机高分子等薄膜，同时还能进行其相应的激光与物质相互作用和成膜过程的物理、化学等方面的基础研究．激光分子束外延是近几年才出现，具有重要学术意义和广泛的应用前景，现正在发展和完善的一种高精密新型制膜技术．经过两年多的多方合作与共同努力，由物理所牵头与沈阳科仪研制中…     

白光干涉法测量薄膜表面微观不平度的研究

文中提出了一种白光干涉法测量薄膜表面微观不平度的方法。无需测量干涉条纹，通过对透明薄膜的反射光谱进行分析，可以测出薄膜的厚度。测试膜片上不同点的厚度，可以得到物体表面微观状貌。该方法测量精度高、对薄膜无破坏作用。薄膜厚度测量范围为0．2-小于20μm，无横向测试范围的限制。在对SiO2薄膜的测试中，和椭圆偏振仪的测试结果相对照，纵向测量误差小于2nm。文中介绍的测试系统结构简单，测试精度高，测试结果可靠，具有较强的实用性。文章最后给出了对介质薄膜软酸铅(PbTiO3)表面的测试研究结果。     

用激光干涉法实时监控同轴磁控溅射ZnO薄膜的厚度

本文介绍了一种在我所生产的TCJ-300型同轴磁控溅射设备上采用激光实时监控ZnO薄膜厚度的方法.实验结果表明,该方法与其它膜厚监控方法相比较具有多种优点:它可以在溅射过程中实时显示薄膜的厚度、均匀性和溅射速率等;本实验装置简单;操作方便;其监控精度优于1.5%.     

利用楔形薄膜干涉测定液体的折射率

介绍一种利用上下分界面反射率不同的楔形薄膜干涉测量液体折射率的方法，并进行了实际测量，且分析了产生误差的原因。该方法具有待测量少、简便易行、精度高等优点。     

采用梯形棱镜波前分割的激光干涉光刻技术

光学光刻技术在微细加工和集成电路(IC)制造中一直是主流技术。随着IC集成度的提高,要求越来越高的光刻分辨力,但光学光刻的分辨极限受光刻物镜数值孔径(NA)和曝光波长(λ)的限制。激光干涉光刻技术具有高分辨、大视场、无畸变、长焦深等特点,其分辨极限为λ/4,在微细加工、大屏幕显示器、微电子和光电子器件、亚波长光栅、光子晶体和纳米图形制造等领域有广阔的应用前景。阐述了激光干涉光刻技术的基本原理。提出了一种采用梯形棱镜作为波前分割元件的激光干涉光刻方法。建立了相应的曝光系统,该系统可用于双光束、三光束、四光束和五光束等多光束和多曝光干涉光刻。给出了具有点尺寸约220nm的周期图形阵列的实验结果。     

飞秒激光制备CdS薄膜滤波器的研究

采用脉冲飞秒激光沉积方法,在石英衬底上制备了CdS薄膜滤波器.研究显示衬底温度在100～600℃范围内变化对CdS薄膜衬底的结构及光学特性有重要影响,在450℃的衬底温度下所生长的CdS薄膜具有较好的结构质量,该薄膜在500nm附近具有较陡的吸收带边及良好的光学滤波性能.     

飞秒激光制备CdS薄膜滤波器的研究

采用脉冲飞秒激光沉积方法,在石英衬底上制备了CdS薄膜滤波器.研究显示衬底温度在100～600℃范围内变化对CdS薄膜衬底的结构及光学特性有重要影响,在450℃的衬底温度下所生长的CdS薄膜具有较好的结构质量,该薄膜在500nm附近具有较陡的吸收带边及良好的光学滤波性能.     

Antireflection and light trapping of subwavelength surface structures formed by colloidal lithography on thin film solar cells

In this paper, we present a novel design of a surface nanostructure that suppresses the reflectivity and provides forward diffraction for light trapping. The structure under study comprises periodic nanoislands fabricated using self‐assembly polystyrene spheres, which are applicable to large‐area fabrication. We also show preliminary fabrication results of the proposed structure. The periodic nanoislands reduce the reflectivity through gradient effective refractive indices and enhance light trapping through diffraction in a periodic structure. We first systematically study the antireflection and light trapping effects using a rigorous coupled‐wave analysis and then calculate the short‐circuit current density of a 2‐μm‐thick crystalline silicon with periodic nanoislands and an aluminum back reflector. The optimum short‐circuit current density with periodic nanoislands achieves 25 mA/cm² theoretically, which shows a 76.9% enhancement compared with that of bare silicon. Moreover, the structure also provides superior photocurrent densities at large angles of incidence, compared with conventional antireflection coatings. Copyright © 2011 John Wiley & Sons, Ltd.     

Fabrication of hydrophobic structures on coronary stent surface based on direct three-beam laser interference lithography

To solve the problems with coronary stent implantation, coronary artery stent surface was directly modified by three-beam laser interference lithography through imitating the water-repellent surface of lotus leaf, and uniform micro-nano structures with the controllable period were fabricated. The morphological properties and contact angle (CA) of the microstructure were measured by scanning electron microscope (SEM) and CA system. The water repellency of stent was also evaluated by the contact and then separation between the water drop and the stent. The results show that the close-packed concave structure with the period of about 12 μm can be fabricated on the stent surface with special parameters (incident angle of 3°, laser energy density of 2.2 J?cm-2 and exposure time of 80 s) by using the three-beam laser at 1 064 nm, and the structure has good water repellency with CA of 120°.     

VOx薄膜的sol-gel法制备

通过对工艺条件的研究,解决了钒有机溶胶与基片的亲水性问题,提出了成膜牢固的亲水处理方法,制备出了无裂纹、致密性好的VOx薄膜。测量结果表明,520℃热处理条件下的VOx薄膜样品的平均电阻温度系数达到了3.95%K–1。而470℃热处理下的VOx薄膜样品,其升降温阻温特性一致性很好,可用作高灵敏度红外探测器敏感元材料。     

PECVD法制备类金刚石薄膜结构和表面形貌分析

以CH4为碳源,Ar气为载气,采用等离子体增强化学气相沉积法(PECVD)在硅(100)衬底上制备了类金刚石(DLC)薄膜。利用拉曼(Raman)光谱仪与原子力显微镜(AFM)对其结构与表面形貌进行了表征。结果表明:所制备的DLC薄膜是含sp3和sp2混合键的非晶态碳膜,其表面均匀、光滑、致密;且随着射频功率的提高,薄膜的平均晶粒直径由8.0nm降为4.2nm,粗糙度由2.2nm减为0.9nm。     

Fabrication of antireflection nanostructures by hybrid nano-patterning lithography

Antireflection (AR) nanostructures are fabricated on a glass substrate using hybrid nano-patterning lithography (H-NPL) consisting of nanosphere lithography (NSL) and UV-nanoimprint lithography (UV-NIL). The shape and diameter of the AR nanostructures were controlled by fabricating Si masters with different RIE conditions. The shapes of the AR nanostructures were a pillar-type and a corn-type. The diameters of the AR nanostructures were about 350 and 250 nm, respectively. AR nanostructures were successfully nanoimprinted on glass in accordance with Si master prepared by NSL. The pillar-type AR nanostructure with diameter of 350 nm exhibited the transmittance of over 98% in the wavelength range from 1100 to 2200 nm. From the results, the fabricated AR nanostructures demonstrate the possibility to improve the efficiency of optoelectronic devices such as a photo-detector and an IR-LED.     

脉冲激光扫描淀积类金刚石薄膜

采用能量密度为1.178×109W/cm2的XeCl准分子激光直接辐照高纯度的石墨靶,并同时采用辅助放电,在1×10-5Torr的真空环境中,于温度为80℃的Si(100)的基片上淀积出类金刚石薄膜,Raman光谱显示在1330cm-1处出现较强的散射峰值;对薄膜红外光谱进行测试,其光谱在2900cm-1处有吸收峰,表明所淀积的类金刚石薄膜含有C-H键,其H元素与C元素的比为45%.薄膜的电阻率为1.89×106Ω/cm,通过光吸收测得的该薄膜的能隙为1.55eV.     

Transformation process of laser ablated PZT thin films

Transformation behavior of piezoelectric lead zirconate titanate (PZT) thin films prepared by laser ablation on unheated Al₂O₃ substrates was investigated within a broad temperature region. As-deposited films were mainly amorphous containing some microcrystalline perovskite and pyrochlore phases. The rhombohedral perovskite was the main phase in the films annealed between 500 and 800°C. These films also contained some pyrochIore, PbTiO₃, PbO, and ZrO₂. The PbO and ZrO₂ disappeared in the optimal annealing temperature interval of 700 to 800°C. Decomposition reactions took place above 800°C due to evaporation of lead and diffusion reactions occurred between substrate and film so that the films annealed at 1100°C consisted of ZrO₂, TiO₂, and PbO.     

Sacrificial film-assisted nanoimprint lithography

We have demonstrated a nanopattterning technique that combines the use of sacrificial film and nanoimprint lithography. The sacrificial film serves as a ‘transient substrate’ during the nanoimprinting steps. The use of a sacrificial film improves the patterning yield significantly because the de-molding is achieved by etching off the sacrificial film, instead of a mechanical de-molding as in conventional nanoimprint lithography. This patterning technique is an easy method to build up multilayer structure from a single type of polymer. The method is also highly versatile; both substrate supported and freestanding nanostructures can be easily achieved by this technique.     

激光脉宽对光学薄膜元件热损伤的影响

纳秒量级及以下脉宽激光致光学薄膜元件的损伤研究持续了几十年,但纳秒量级以上脉宽却很少提及。因此,针对10 ns~1 ms量级区间不同脉宽激光辐照光学薄膜元件产生的热损伤进行了研究,计算了高反膜、增透膜和干涉滤光片三种典型光学薄膜元件的温度场分布,并分析了其激光热损伤特性。结果表明,对于长脉宽激光,热扩散深度大,薄膜损伤的电场效应被削弱,热传导效应在损伤中占据主导地位,损伤可至基底;短脉宽激光损伤对薄膜内部的电场分布更为敏感,损伤发生在温度最高值附近的膜层区域。进而开展了10 ns与1 ms脉宽激光致光学薄膜元件的损伤实验,损伤阈值及形貌特征与温度场计算结果显示的热损伤特性相符。     

脉冲激光纳米薄膜制备技术

脉冲激光薄膜沉积（ＰＬＤ）是近年来受到普遍关注的制膜新技术。简要介绍了该技术的物理原理;探讨了脉冲激光沉积制膜的物理过程,激光作用的极端条件及等离子体羽辉形成的控制对薄膜成长的影响;评价了脉冲激光沉积技术在多种功能材料薄膜,特别是纳米薄膜及多层结构薄膜的制备方面的特点和优势,结合自行研制的设备,介绍了在ＰＬＤ基础上发展起来的兼具分子束外延（ＭＢＥ）技术特点的激光分子束外延技术（Ｌ－ＭＢＥ）,指出脉冲激光沉积技术在探讨激光与物理相互作用和薄膜成膜机理方面的作用,尤其是激光分子束外延技术在高质量的纳米薄膜和超晶格等人工设计薄膜的制备上显现出的巨大潜力。