共查询到20条相似文献,搜索用时 15 毫秒
1.
Mützel M Tandler S Haubrich D Meschede D Peithmann K Flaspöhler M Buse K 《Physical review letters》2002,88(8):083601
In atom lithography with optical masks, deposition of an atomic beam on a given substrate is controlled by a standing light-wave field. The lateral intensity distribution of the light field is transferred to the substrate with nanometer scale. We have tailored a complex pattern of this intensity distribution through diffraction of a laser beam from a hologram that is stored in a photorefractive crystal. This method can be extended to superpose 1000 or more laser beams. The method is furthermore applicable during growth processes and thus allows full 3D structuring of suitable materials with periodic and non-periodic patterns at nanometer scales. 相似文献
2.
原子光刻实验中, 激光驻波场能起到原子透镜的效果, 实现原子汇聚. 激光驻波场与沉积基片间的距离对形成纳米条纹结构的质量具有重要影响. 利用高斯光束传播规律, 提出了一种能够定量判断激光驻波场与沉积基片相对位置的实验方法. 该方法通过调节装载有凸透镜和反射镜的精密位移台改变驻波场距基片的距离, 利用光电探测器接收反射光强的变化, 将位移改变量转变为接收器的电压信号. 利用驻波场激光束光斑直径值, 实现准确定位驻波场与基片的距离. 对上述实验过程进行数值模拟, 数值计算的结果和实验结果高度符合. 该方法实现了准确定位驻波场距基片的距离, 为后续深入研究驻波场和基片间距离对沉积纳米条纹结构质量的影响提供实验基础. 相似文献
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High-resolution atomic channeling using velocity-controlled atoms may be able to overcome precision limitations of the conventional
atom lithography. We have experimentally clarified the dependence of line width and contrast of atomic patterns in the channeling
region on the velocity spread of the atomic source for the first time. Thermal or velocity-selected atomic beams prepared
with a one-dimensional magneto-optical trap were employed as the atomic sources. We investigated the channeling characteristics
by measuring the frequency shifts of the atomic absorption spectra in an intense standing wave light field. As a result, we
can show that narrower line width and higher contrast atomic patterns are obtained as the velocity spread becomes narrower.
An atomic pattern with an estimated line width of 57 nm was generated when the velocity spread of the atomic source was almost
50 m/s, that is, 1/6 that of the thermal beam.
Received: 16 June 2001 / Published online: 7 November 2001 相似文献
5.
R.R. Chaustowski V.Y.F. Leung K.G.H. Baldwin 《Applied physics. B, Lasers and optics》2007,86(3):491-496
Sources of rare gas atoms in excited metastable states have been used to expose photoresist-coated substrates to demonstrate
atom lithography. These thermal atomic beams are usually created by discharge sources that also produce copious amounts of
UV radiation. The UV radiation simultaneously illuminates the substrate and may play a complementary role in altering the
photoresist together with the metastable atoms. In the experiments reported here, we have isolated the UV component using
a magnetic hexapole lens to focus a thermal beam of metastable helium atoms around a fiducial mask that blocks the UV light.
This creates an atom lithography exposure that is the result of illumination by the atoms alone. We have also modelled the
performance of the magnetic hexapole lens as a potentially useful device for atom lithography.
PACS 39.25.+k; 81.16.Nd 相似文献
6.
基于半经典理论,分析了中性钠原子在激光驻波场中的受力特征,以此为基础分别对不同纵向运动速度和横向运动速度条件下中性钠原子的运动轨迹进行了仿真运算,得到了不同速度条件下中性钠原子的运动轨迹特征,基于累计算法进一步对不同速度条件下中性钠原子的沉积特性进行了仿真,当钠原子的纵向运动速度符合最可及速度(740 m/s)时,纳米沉积条纹的半高宽为2.78 nm,条纹对比度为38.5 ∶1,当纵向运动速度偏离最可及速度(350 m/s)时,纳米沉积条纹的半高宽为29.1 nm,其对比度下降为15 ∶1.而当中性钠原子
关键词:
原子光刻
激光驻波场
条纹半高宽
条纹对比度 相似文献
7.
采用量子模型对近共振激光驻波原子透镜会聚Cr原子束、形成纳米量级光栅结构的物理过程进行数值模拟。为提高原子透镜的成像质量,对各种像差,如衍射像差、球差、色差、及原子束发散角、原子磁支能级、原子同位素等因素引起的像差进行了理论分析。模拟结果表明,相比粒子光学模型,量子模型能更加精确地描述原子会聚结果,且能解释原子在驻波光场中的衍射现象。在各种像差中,原子束发散角是最主要的因素,其影响大于衍射像差、球差、色差。原子的磁支能级、同位素等因素对像差影响很小,可以忽略不计。激光冷却准直原子束的方法可以减小束发散角引起的像差,压缩原子速度Vz分布范围的方法可以减小色差。 相似文献
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《Current Applied Physics》2010,10(6):1436-1441
We show an easy method to eliminate the undercut profile of photoresist by fabricating periodic nano-patterns on a substrate using interference lithography. An undercut phenomenon occurs frequently on the sidewall of photoresist patterns because of the 3-dimensional intensity distribution generated when two beams are merged to make an interferogram. This is mainly caused by the vertical interference between the incident beam and the one reflected from the surface of a substrate, and bottom-anti-reflection-coating (BARC) material is usually used to prevent beams from being reflected onto the substrate. We propose a simple post-process which helps researchers fabricate well-defined patterns without using BARC material. We developed this process to fabricate stamps for nano-imprint lithography at low cost, and show the results of our nano-imprint process which transfers patterns on a stamp directly through thermal resist. 相似文献
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分析了椭圆激光驻波场的偏斜对中性原子运动过程和沉积过程的影响,对不同偏斜角度椭圆激光驻波场作用下中性铬原子沉积纳米光栅结构的特性进行了仿真研究,由仿真结果可以看出,随着偏斜椭圆形激光束偏斜角的增加,对应于不同y平面,激光驻波场汇聚中性原子所形成纳米光栅条纹的对比度不断减小、半高宽不断增大.当椭圆长短轴之比为2:1条件下,椭圆激光驻波场的偏斜角为0°时,纳米光栅的条纹半高宽为3.2 nm,条纹对比度为36:1,而当偏斜角为15°时,激光驻波场中心位置处的沉积条纹的半高宽为6.5 nm,条纹对比度为24:1,而当椭圆激光驻波场偏斜角度达到30°时,沉积条纹的单峰结构将会产生分裂,形成了双峰结构,且随着偏斜角的增加,沉积条纹的分裂越严重,纳米光栅的沉积质量越差.对于其他长短轴比例条件下的激光场亦可根据比例关系获得相应的纳米光栅沉积特性.
关键词:
原子光刻
偏斜椭圆激光驻波场
纳米光栅 相似文献
11.
We start from the intensity distribution of a standing wave (SW) laser field and deduce the classical equation of atomic motion. The image distortion is analyzed using transfer function approach. Atomic flux density distribution as a function of propagation distance is calculated based on Monte-Carlo scheme and trajectory tracing method. Simulation results have shown that source imperfection, especially beam spread, plays an important role in broadening the feature width, and the focus depth of atom lens for real atomic source is longer than that for perfect source. The ideal focal plane can be easily determined by the variation of atomic density at the minimal potential of the laser field as a function of traveling distance. 相似文献
12.
O. Kashin M. Homann V. Matusevich F. Setzpfandt T. Pertsch R. Kowarschik 《Applied physics. B, Lasers and optics》2011,103(3):547-551
We present a new method for nanoscale atom lithography. We propose the use of a supersonic atomic beam, which provides an
extremely high brightness and cold source of fast atoms. The atoms are to be focused onto a substrate using a thin magnetic
film, into which apertures with widths on the order of 100 nm have been etched. Focused spot sizes near or below 10 nm, with
focal lengths on the order of 10 μm, are predicted. Our method can be implemented in a highly parallel manner, enabling simultaneous
fabrication of 106 identical elements, and it is applicable both to precision patterning of surfaces with metastable atomic beams and to direct
deposition of material. 相似文献
13.
We have created periodic nanoscale structures in a gold substrate with a lithography process using metastable triplet helium atoms that damage a hydrophobic resist layer on top of the substrate. A beam of metastable helium atoms is transversely collimated and guided through an intense standing-wave light field. Compared to commonly used low-power optical masks, a high-power light field (saturation parameter of 107) increases the confinement of the atoms in the standing wave considerably, and makes the alignment of the experimental setup less critical. Due to the high internal energy of the metastable helium atoms (20 eV), a dose of only one atom per resist molecule is required. With an exposure time of only eight minutes, parallel lines with a separation of 542 nm and a width of 100 nm (one-eleventh of the wavelength used for the optical mask) are created.PACS 32.80.Lg; 39.25.+k; 81.16.Nd 相似文献
14.
The scattering and focusing characteristics of a Gaussian beam with phase distribution is studied by a stepped index Luneberg lens. A model experiment was performed using a six-layer spherical lens. Two kinds of beams, that is, broad and narrow beam are examined for the incident Gaussian beam. We find that focusing effect of a narrow beam is wholly lower than that of a broad beam. The focal point is also shifted toward outer of sphere because of phase lag for the beam source. The spot size equals almost the wavelength for the various beam parameters. 相似文献
15.
Atom lithography with a cold, metastable neon beam 总被引:1,自引:0,他引:1
P. Engels S. Salewski H. Levsen K. Sengstock W. Ertmer 《Applied physics. B, Lasers and optics》1999,69(5-6):407-412
We study different aspects of atom lithography with metastable neon atoms. Proximity printing of stencil masks is used to
test suitable resists that are sensitive to the internal energy of the atoms, including dodecanethiols on gold and octadecyltrichlorosilanes
grown on a SiO2 surface. As an example of patterning the atomic beam with laser light, we create parallel line structures on the surface
with a periodicity of half the laser wavelength by locally de-exciting the atoms in a standing quenching wave.
Received: 29 June 1999 / Revised version: 30 August 1999 / Published online: 10 November 1999 相似文献
16.
基片衍射对会聚激光驻波场中原子波包几率密度演化的影响 总被引:1,自引:0,他引:1
针对激光会聚铬原子沉积实验,运用标量衍射理论,通过数值模拟研究了基片衍射对会聚激光驻波场中原子波包几率密度演化的影响。结果显示基片衍射的影响会随激光中轴线与基片沉积表面距离b0的变化而变化。相对于非衍射情况,衍射效应会提高激光驻波场中会聚平面内原子波包几率密度分布的中心值,同时减小其半峰全宽。当参量b0=-0.2w0(w0为高斯光束的束腰半径)时,原子波包几率密度的会聚平面和基片沉积表面完全重合。此处,衍射时原子波包几率密度分布的中心值为1.26,其半峰全宽为5.62 nm,两者分别为非衍射时的1.1倍和0.94倍。 相似文献
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Golub I 《Optics letters》2007,32(15):2161-2163
A new type of optical configuration--a solid immersion axicon (SIAX)--is proposed. Similar to a solid immersion lens for Gaussian beams, a SIAX increases the diffraction-limited resolution for propagating Bessel beams by a factor of the refractive index of the media. For incident radial polarization, the scheme generates the smallest focal spot available for nondiffracting beams. The configuration can be implemented with either refractive or diffractive axicons. The scheme may find use in microscopy, imaging, lithography and data storage, and other applications requiring nondiffracting beam characteristic features such as very large focal depth. 相似文献
20.
Writing a superlattice with light forces 总被引:1,自引:0,他引:1
Th. Schulze B. Brezger R. Mertens M. Pivk T. Pfau J. Mlynek 《Applied physics. B, Lasers and optics》2000,70(5):671-674
In atom lithography the conventional roles played by light and matter are reversed. Instead of using a solid mask to pattern
a light beam, a mask of light is used to pattern a beam of neutral atoms. In this paper we report the production of different
chromium dot arrays with quadratic symmetry. The lattice period depends on the relative polarization and the phase of the
two standing waves generating the light mask. A small angular misalignment of the laser beams breaks the high symmetry and
a chromium superlattice is written, that is a continuous periodic change between two different quadratic lattices. The structures
exhibit lines with a FWHM below 50 nm and clearly separated chromium dots with a FWHM below 70 nm.
Received: 30 September 1999 / Revised version: 14 February 2000 / Published online: 5 April 2000 相似文献