光刻胶灰化用于全息离子束刻蚀光栅制作

针对全息离子束刻蚀衍射光栅制作中，光刻胶光栅浮雕图形的制作是至关重要和困难的，引入伤反应离子刻蚀对光刻胶光栅进行灰化处理，给出光刻胶灰化技术在全息离子束刻蚀衍射光栅制作闪耀光栅、浅槽矩形位相光栅、自支撑透射光栅中的具体应用。实验结果表明，这一新工艺的突出优点是降低了苛刻的全息曝光、显影要求，使得光栅线条光滑、线空比和槽深可控。     

反应离子束刻蚀石英同质掩模制作小阶梯光栅

离子束刻蚀作为真空技术的一种重要应用,已广泛运用于现代微电子器件和微光学器件的制作工艺中。本文结合反应离子束刻蚀与全息光刻技术,针对线密度较低的小阶梯光栅,倾斜刻蚀石英同质掩模,制作了三种在紫外光和可见光波段透射闪耀的小阶梯光栅。第一种光栅线密度为360lp/mm,闪耀角16.8°,在325nm波长的透射衍射效率为74%;第二种和第三种光栅线密度均为400lp/mm,闪耀角为34.7°和43°,其在632.8nm波长的透射衍射效率分别为63%和57%。结果表明,使用CHF_3作为刻蚀气体的反应离子束刻蚀石英同质掩模,所制作的小阶梯光栅在其工作波段透射闪耀的衍射效率为理论值的75%以上,为全息离子束制作低线密度大闪耀角的光栅提供参考。     

反应离子束刻蚀工艺制作闪耀罗兰光栅

相比类矩形槽罗兰光栅,闪耀罗兰光栅的衍射效率较高,更有利于光谱分析仪器的设计与应用,而国内外尚无产品级闪耀罗兰光栅产品.本文通过类矩形槽形及闪耀槽形的衍射效率优化设计及对比,获得了闪耀槽形优化设计结果;利用反应离子束刻蚀设备制作出3块200~450 nm波段、线密度为2 400 gr/mm、口径为Φ63.5 mm的闪耀罗兰光栅,其中光栅2的峰值衍射效率达到了65%@220 nm,较HORIBA Jobin Yvon公司生产的类矩形槽罗兰光栅产品整体衍射效率高25%,与理论衍射效率相当.实验结果表明,本文所采用的反应离子束刻蚀工艺可实现高衍射效率闪耀罗兰光栅制作,且工艺可控、稳定,所制作的闪耀罗兰光栅衍射效率高于国外同类产品.     

用光学全息方法研制软X射线Bragg-Fresnel光学元件

介绍了软X射线Bragg Fresnel光学元件的特点 ,并以磁控溅射法制备多层膜 ,再采用光学全息方法在涂有光刻胶的多层膜表面上形成波带片图形 ,通过显影、离子束刻蚀完成元件的制作     

集成光学头用的波导光栅耦合器的制作与性能研究

对集成光学头用的波导光栅器件的制作技术进行了研究。采用热氧化和离子束增强沉积方法分别在Si衬底上制备了SiO2层和玻璃波导层,制成了以Si为基底的光波导．采用PCVD法在该光波导上制备Si-N层,用全息干涉光刻法在Si-N层上制作了周期为1μm的等周期直线光栅,并用离子束刻蚀技术将该光栅转移到了Si-N层中。光栅的倾角约20～30°;一级衍射效率可达120％,具有明显的闪耀光栅特征。该光栅可用作导波光输入输出耦合器。     

用光学全息方法研制软X射线Bragg—Fresnel光学元件

介绍了软Ｘ射线Ｂｒａｇｇ－Ｆｒｅｓｎｅｌ光学元件的特点,并以磁控溅射法制备多层膜,再采用光学全息方法在涂有光刻胶的多层膜表面上形成波带片图形,通过显影、离子束刻蚀完成元件的制作 。     

深蚀刻玻璃光波导光栅的研究

采用全息法制备了光刻胶光栅，并用该光栅掩膜离子蚀刻，刻得槽深为１．６μｍ的玻璃光栅，再采用Ｋ＾＋／Ｎａ＾＋交换法制备玻璃光波导光栅，用６３３ｎｍ波长激光由一端棱镜耦合输入，经过光栅，由另一端面输出，在实验中观察到多级布拉格衍射，一级布拉格衍射效率最高达９０％。     

液晶阵列四次光刻工艺中光刻胶灰化工艺的研究

光刻胶的灰化是TFT四次光刻工艺的核心工艺之一,本文研究了TFT四次光刻工艺中光刻胶的灰化工艺,得到了功率、气压、灰化气体对光刻胶灰化速率和均匀度的影响趋势。研究表明,纯O2气体对光刻胶有很好的灰化作用,但其会导致下一层金属Mo的表面发生氧化,从而阻止下层金属的刻蚀。在灰化气体中加入少量SF6,能有效地去除生成的金属氧化物,提高下层金属的刻蚀速率。在优化的灰化工艺条件下,制作的TFT具有良好的电学特性。     

反应离子束刻蚀母盘研究

对反应离子束刻蚀母盘和玻璃衬底光盘的工艺进行了探讨,在该工艺中,光刻胶用于图形掩膜,ＣＦ４气体用于反应离子束刻蚀并将预刻槽转移到玻璃衬底上,预刻槽的形状和深度由刻蚀机的设置条件控制。ＳＥＭ照片表明,刻蚀在玻璃衬底上的预刻槽的道间距为１．６μｍ,槽深０．１μｍ,槽宽０．６μｍ,符合光盘预刻槽的基本标准,说明该工艺是微细加工母盘凹坑和预刻槽的较好办法。     

RIBE-5型反应离子束刻蚀机

反应离子束刻蚀技术是近年来发展起来的一种微细加工技术，它利用反应离子束轰击团体表面时发生的溅射效应和化学反应剥离加工工作上的几何图形。具有极高的分辨率，能够控制槽深和槽壁角度，表面应力小。反应离子束刻蚀技术已有效地用于研究和制造大规模和超大规模集成电路，声表面波器件，磁泡存储器，微波器件，集成光路，超导器件，闪烁光栅等。本文叙述了一台ＲＩＢＥ－５型反应离子束刻蚀机的工作原理、结构特点、技术性能和刻蚀工艺实验结果．     

Comparison of mechanically ruled versus holographically varied line-spacing gratings for a soft-x-ray flat-field spectrograph

Recent progress in the design of aspheric wave-front recording systems has permitted the manufacture of holographic gratings with highly variable groove densities that are suitable for flat-field spectrographs. A holographic grating thus recorded was processed to produce a laminar profile by use of reactive-ion etching. Measurements are reported of the absolute diffraction efficiency of this grating and of a comparable mechanically ruled grating. It is found that the holographic grating is much more effective in suppressing the higher orders. The spectral resolution was determined by use of a carbon Kalpha x-ray generator and a spectrograph with an imaging detector. The spectral resolution of the holographic grating was approximately 3 times worse than that of the ruled grating.     

分布反馈量子级联激光器的光栅制备

利用全息曝光方法制备了分布反馈量子级联激光器的光栅掩模,选择和发展了恰当的用于InGaAs/InP材料的光栅腐蚀优化工艺,得到腐蚀规律,讨论了腐蚀机制。在量子级联激光器的InGaAs/InP层上制备光栅得到分布反馈量子级联激光器,其单模特性较好,信噪比大于30dB。     

Holographic DFB Dye Lasers

A new simple type of DFB dye laser is proposed. The laser consists of a dye cell and a transparent phase holographic grating mounted on the front window of the cell. In the experiment, high-quality stable transparent holographic gratings were recorded in bichromated gelatine with a single mode He-Cd laser. When pumped perpendicular to the surface of the grating the DFB laser emitted a narrow spectral line independently of the width and the position of the pump spectrum. A linewidth of 0·01 nm was measured under pumping with broadband radiation of 20 nm spectral width. Either a set of holographic gratings of a different period or a fan-shaped grating may be used in the laser for stepped or continuous spectral tuning.     

Diffraction properties of volume holographic gratings for an ultrashort pulsed beam with different polarization states readout

The diffraction properties of volume holographic gratings are studied when the gratings are illuminated by an ultrashort pulsed beam with different polarization states. The developed coupled wave theory of Kogelnik is used. Considering the dispersion effect of the grating media, solutions for the diffracted and transmitted intensities, diffraction efficiencies and the bandwidths of the gratings are given in transmission volume holographic gratings and reflection volume holographic gratings. The bandwidths of the gratings are reduced by the dispersion effect of the grating media. They also have different influences on the diffraction of an ultrashort pulsed beam with different polarization states. For different values of the ratio of the spectral bandwidth of the input pulse to that of the grating, the changes of the spectral and temporal distributions of the diffracted intensities, as well as the diffraction efficiencies of the gratings are shown.     

Fabrication of holographic blazed grating with Fourier synthesis exposure

A simple, direct, and universal fabrication method for holographic blazed gratings is proposed and a 79 lines/mm holographic echelle grating with 4 μm depth quasi-triangular grooves experimentally demonstrated as an example of a blazed grating fabricated directly by Fourier synthesis exposure. With the method, we converted a periodic grating groove profile into the exposure energy spatial distribution on the surface of a photoresist with the response characteristics of the particular photoresist. Then the exposure energy could be decomposed into a series of sinusoidal functions using Fourier series, and realized by superposing a series of two-beam interference patterns. In contrast with mechanically ruled gratings, the fabrication process of holographic gratings is quite quick and low cost, and especially no Rowland ghosts appear in their dispersion spectrum. The reported work will offer a new approach for blazed grating fabrication with a holographic process.     

Apodizing holographic gratings for dual-wavelength operation of broad-area semiconductor lasers

Apodizing holographic gratings are designed to have a Gaussian reflectivity profile in the -1 order and a complementary reflectivity profile in the specular (0) order. They are obtained by the interference of two Gaussian beams on a glass plate covered with a photoresist. These gratings are intended to be used as the coupler of the external cavity of a broad-area semiconductor laser. When the grating is oriented to get the -1 order counterpropagating with respect to the incident beam, single-longitudinal- and single-lateral-mode operation is obtained. We report on the fabrication technique of an apodizing holographic grating designed to allow lasing on two wavelengths simultaneously, with a preselected wavelength separation. The results obtained with a commercial broad-area laser are presented.     

线性啁啾相位掩模的设计

啁啾相位掩模法是啁啾光纤光栅的一种非常重要的制作方法。本文研究讨论了用全息干涉方法制作线性啁啾位相掩模的设计方法,提出用两球面波干涉产生条纹密度随空间距离线性变化的干涉条纹记录啁啾位相光栅,按设定光栅端点空频和端点空频差两种优化设计方法设计了长度100mm、啁啾量1nm/mm的线性啁啾光栅,理论和实验结果给出两种设计方案的非线性系数分别为2.5%和1.6%,理论设计和实验结果相符。     

Facile route of flexible wire grid polarizer fabrication by angled-evaporations of aluminum on two sidewalls of an imprinted nanograting

In this study, we report a new method to fabricate a wire grid polarizer (WGP) that greatly relaxes the requirement on patterning and etching, and can be easily applied to produce flexible WGPs. The technique is to pattern a high aspect ratio and narrow linewidth grating by nanoimprint lithography followed by two angled aluminum depositions in opposite directions to produce the narrow spacing between the aluminum lines required for a visible band WGP. Anisotropic reactive ion etching is used to remove the aluminum deposited at the top of the grating but leave the aluminum layer on the grating sidewalls, thereby forming a metal wire grid with much smaller spacings than a lithographically defined grating. As a result, the fabricated WGP showed good performance in a wide range of visible wavelength.     

Holographic gratings for the Far Ultraviolet Spectroscopic Explorer: development, imaging, and efficiency tests of two prototypes

We report on a study and test of two 6000-groove/mm prototype holographic gratings for NASA's FarUltraviolet Spectroscopic Explorer (FUSE) mission. The first grating was designed and developed onthe basis of the FUSE requirements as specified at the end of the first study in 1992. This design relieson an ellipsoidal grating, recorded with aberrated wave fronts to correct sagittal coma. The secondgrating corresponds to the new design adopted after the complete mission was restructured in1993. With this solution a new family of spherical holographic gratings recorded with stigmaticsources was permitted to increase the aperture size while simplifying the figuring and recording of theblank. The design, fabrication, and testing of each prototype are described, and we show that thechallenging requirement of a 30,000 resolving power at 1000 ?, with a 25% groove efficiency, is reached.     

A treatment of the general volume holographic grating as an array of parallel stacked mirrors

An alternative model to Kogelnik's coupled wave theory of the volume holographic grating is developed in terms of an infinite array of parallel stacked mirrors. The model is based on summing the individual Fresnel reflections from an infinite number of infinitesimal discontinuities in the permittivity profile. The resulting first-order coupled partial differential equations are solved in a rotated frame of reference in order to derive analytical expressions for the diffraction efficiency of the general slanted grating at an arbitrary angle of incidence. The model has been tested using computational solutions of the Helmholtz equation for the unslanted reflection grating. For index modulations characteristic of modern silver halide and photopolymer materials used in display and optical element holography the new model shows excellent agreement with the numerical results. Kogelnik's model also provides good agreement as long as the dephasing parameter is not too large. The model has been tested against Kogelnik's theory for a variety of cases with finite fringe slant with good agreement for typical index modulations. A further advantage of the new model is that colour holographic gratings may be treated at and away from Bragg resonance. Numerical and analytical results are presented concerning the diffractive efficiency of two- and three-colour holographic gratings.