惯性约束聚变实验用平面薄膜的制备及其表面图形的引入

平面薄膜是ICF分解实验的重要靶型,以半导体技术结合重掺杂自截止腐蚀制备厚度为3－4um的Si平面薄膜,以热蒸发结合脱膜工艺制备Al平面薄膜,两者的表面粗糙度分别为30nm和10nm左右;进一步采用离子束刻蚀在平面薄膜的表面引入网格或条状图形,获得测量成像系统像传递函数的刻蚀膜,控制离子束刻蚀工艺的参数以实现图形的精确转移。     

Surface characteristics of SiO2-TiO2 strip fabricated by laser direct writing

SiO2-TiO2 sol-gel films axe deposited on SiO2/Si by dip-coating technique.The SiO2-TiO2 strips are fabricated by laser direct writing using an ytterbium fiber laser and followed by chemical etching.Surface structures,morphologies and roughness of the films and strips are characterized.The experimental results demonstrate that the SiO2-TiO2 sol-gel film is loose in structure and a shrinkage concave groove forms if the film is irradiated by laser beam.The surface roughness of both non-irradiated and laser irradiated areas increases with the chemical etching time.But the roughness of laser irradiated area increases more than thalt of non-irradiated area under the same etching time.After being etched for 28 s,the surface roughness value of the laser irradiated area increases from 0.3 nm to 3.1 nm.     

Evolution of the roughness of amorphous quartz surfaces and Cr/Sc multilayer structures upon exposure to ion-beam etching

The effect of ion-beam etching on surfaces of Cr/Sc multilayer structures and amorphous quartz roughness is studied. The dependence of roughness on the depth of etching, incidence angle, and ion energy is considered. Optimal parameters of etching which provide minimal evolution of surface roughness are presented.     

静/动态刻蚀对熔石英表面质量和激光损伤的影响

为了研究静/动态刻蚀过程中熔石英表面质量和抗激光损伤性能的演变规律,优化化学刻蚀工艺,使用HF酸缓冲液对熔石英分别进行了不同时间的静/动态刻蚀处理。实验表明,由于兆声场辅助搅拌作用,熔石英动态刻蚀的刻蚀速率快于静态刻蚀。动态刻蚀后熔石英表面均方根(RMS)粗糙度和反射面形分别为 < 1 nm和0.46λ,其3倍频透射率先小幅增加后保持稳定,相比初始表面增加约0.1%。而静态刻蚀使得表面RMS粗糙度和反射面形分别增加至~5 nm和0.82λ,其3倍频透射率先基本不变后下降,相比初始表面下降约0.4%。二者损伤阈值呈现明显不同变化规律:静态刻蚀使熔石英损伤阈值先小幅增加约30%后逐渐降低,动态刻蚀使熔石英损伤阈值增加近一倍后保持相对稳定。结果表明,动态刻蚀后熔石英光学元件性能明显优于静态刻蚀。     

酸蚀深度对熔石英三倍频激光损伤阈值的影响

 采用干涉仪和台阶仪测试蚀刻深度随时间的变化,结合材料去除速率测量,研究了HF酸蚀液对熔石英表面蚀刻的影响。测试了蚀刻后损伤阈值和表面粗糙度的变化。研究表明,熔石英表面重沉积层厚度约16 nm,亚表面缺陷层大于106 nm;重沉积层去除后损伤阈值增大,随亚表面缺陷层暴露其阈值先降低后又增加,最后趋于稳定;然而,随蚀刻时间的增加,其表面粗糙度增大。分析表明,蚀刻到200 nm能有效地提高熔石英的低损伤阈值,有利于降低初始损伤点数量和提高熔石英表面的机械强度。     

Fabrication of single-mode ridge SU-8 waveguides based on inductively coupled plasma etching

In this paper, a systematic study has been performed for the etching of negative photoresist SU-8 2005 using inductively coupled plasma. The etching rate, vertical profile, surface and sidewall roughness of the waveguide were investigated as a function of the chamber pressure, the bias power, the antenna power, the ratio of flow rate of Ar to O₂, and the etching time. The etching parameters were studied in detail and optimized to minimize the surface roughness in etched areas. Ridge MZI waveguides with SU-8 2005 were fabricated under the optimized etching conditions, resulting in smooth and almost vertical patterns. The waveguides showed single-mode propagation at 1550 nm wavelength and low propagation loss of less than 1.565 dB/cm, which was similar to the waveguides fabricated by the wet-etching technique.     

Surface and bulk structural properties of nanostructured porous silicon prepared by electrochemical etching at different etching time

Nanostructured porous silicon (NPSi) is versatile nanomaterials, and attractive area in device application after visible luminescence was observed from NPSi by Canham (1990). NPSi has been prepared by electrochemical techniques with silicon wafer as a based material. The electrolyte solution consists of ethanol and hydrofluoric acid at volume ratio of 1:1. The etching time was varied while other preparation parameters were fixed to produce different porosity of NPSi samples. The structural properties of samples were measured using field emission scanning electron microscope and Raman spectrometer. The surface structural study has shown the surface roughness increase at inertial stage but decrease gradually with longer etching time. However, nanostructured surface was decreased with increasing of etching time. From side view measurement, the nanopillar of NPSi becomes smaller size while increase of etching time. The crystallinity of PSi is observed by Raman scattering varied with different etching time. The photoluminescence measurement will be carried out to study the correlation between optical and structural properties.     

离子源工艺参数对BCB胶刻蚀速率和表面粗糙度的影响

为了研究离子束刻蚀抛光过程中离子源工艺参数对刻蚀速率及表面粗糙度的影响,采用微波离子源为刻蚀离子源,以BCB胶为主要研究对象,研究了离子束能量、离子束电流、氩气流量、氧气流量对BCB胶刻蚀速率及表面粗糙度的影响,获得了离子源工艺参数与刻蚀速率及表面粗糙度演变的关系。研究结果表明,离子束能量在从400 eV增大到800 eV的过程中,刻蚀速率不断增大,从3.2 nm/min增大到16.6 nm/min;离子束流密度在从15 mA增大到35 mA的过程中,刻蚀速率不断增大,从1.1 nm/min增大到2.2 nm/min;工作气体中氧气流量从2 mL/min增大到10 mL/min的过程中,刻蚀速率会整体增大,在8 mL/min处略有下降。表面粗糙度变化不大,可以控制在1.8 nm以下。     

Effect of cathodic arc PVD parameters on roughness of TiN coating on steel substrate

Titanium nitride which is widely used as a hard coating material was coated on tool steel, by physical vapor deposition method. Surface roughness was investigated as a function of deposition rate, substrate bias and temperature, nitrogen flow rate and metal ion etching. The study showed that increase in surface roughness mainly depends on the condition of sample preparation, surface treatment, macro-droplets, pitting defects, rise in compressive stress at higher coating thickness, growth defects and to a lesser extent selection of surface under testing. It was observed that chromium ion etching significantly reduced the surface roughness compared to titanium ion etching.     

Influence of surface preparation on CdZnTe nuclear radiation detectors

High resolution X-ray diffraction (HRXRD), Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM) techniques were used to characterize the surface of CdZnTe (CZT) samples treated by mechanical lapping, polishing and chemical etching processes. The results confirm that the etching process produces the highest intensity diffraction peak, and the best full-width-at-half-maximum (FWHM). Fourier Transform Infrared (FTIR) spectroscopy shows that fine polishing increases the infrared transmission of the CZT sample, while etching with 2% bromine methanol (BM) etching decreases the infrared transmission. Different etchants and concentrations were investigated by comparing the surface morphology and roughness. The bromine methanol etching has shown more flat surface with lower roughness than the other etchants.     

Track sensitivity and the surface roughness measurements of CR-39 with atomic force microscope

Atomic Force Microscope (AFM) has been applied to evaluate the surface roughness and the track sensitivity of CR-39 track detector. We experimentally confirmed the inverse correlation between the track sensitivity and the roughness of the detector surface after etching. The surface of CR-39 (CR-39 doped with antioxidant (HARZLAS (TD-1)) and copolymer of CR-39/NIPAAm (TNF-1)) with high sensitivity becomes rough by the etching, while the pure CR-39 (BARYOTRAK) with low sensitivity keeps its original surface clarity even for the long etching.     

Effect of gas residence time on the morphology of silicon surface etched in SF6 plasmas

This paper describes the effect of the SF₆ gas residence time on the morphology of silicon (1 0 0) samples etched in a reactive ion etching system. Profilometry and atomic force microscopy techniques were used to characterize the etching process focusing attention on the evolution of the surface morphology. Under the condition of variable pressure and gas flow rate, the decrease of the residence time leads to an increase of the silicon etch rate concomitantly with an increase of the surface roughness. Contrary fact is observed when the gas flow is fixed and the pressure is varied. Here, the increasing of residence time leads to a constant increase of silicon etch rate with small variations in final surface roughness. To better understanding this resident time effect, mass spectrometry analyses were realized during the discharge for both gas flow conditions.     

CF_4/Ar/O_2等离子体对熔石英元件的修饰工艺

采用感应耦合等离子体刻蚀技术,以CF4/Ar/O2为反应气体对熔石英元件表面进行修饰,研究并分析了CF4和Ar流量对刻蚀速率、熔石英表面粗糙度和微观形貌的影响。结果表明,CF4化学刻蚀与Ar的物理轰击对熔石英样品表面修饰效果存在一定竞争关系,当它们达到平衡时表面粗糙度最小。通过对不同流量气体刻蚀过后熔石英表面粗糙度和光学显微形貌分析获得了较为理想的气流量配比,该研究为反应等离子体修饰熔石英光学元件以获得较高光学性能提供工艺参考。     

Increased surface roughness by oxygen plasma treatment of graphite/polymer composite

The technology of selective plasma etching was applied to increase the surface roughness of graphite/polymer composite. Etching was performed with a low pressure weakly ionised oxygen plasma created with a RF generator of the output power of 200 W and frequency of 27.12 MHz. The density of charged particles, density of neutral oxygen atoms and the electron temperature was about 1×10¹⁶ m⁻³, 4×10²¹ m⁻³, and 5 eV, respectively. The effects of plasma treatment were observed by scanning electron microscope (SEM), electron microprobe (EMPA) and Talysurf. It was found that the surface roughness was increased by approximately 15 times, from a virgin sample at the roughness of R_a=0.27 μm to a very rough surface with R_a=4 μm. The roughness increased with increasing plasma exposure time. The EMPA results showed that the amount of sulphur in the surface layer decreased with increasing etching time indicating that PPS polymer was the material etched preferentially.     

Influence of low-energy ion treatment on the roughness of glassceramic, alumina, and quartz substrates

The influence of low-energy ion treatment on the roughness of glassceramic, alumina, and quartz substrates is studied. It is found that the surface roughness diminishes after argon ion etching and increases after CCl₄ and SiCl₄ ion etching.     

The effect of pretreatment on adhesive strength of Cu-plated liquid crystal polymer (LCP)

Copper metallization on LCP was carried out by means of electroless plating followed by electroplating and the effect of pretreatment on the adhesive strength of the Cu-plated LCP was investigated in detail. Compared with the other etching agents used here, potassium permanganate was found to be the most effective and the optimum etching time is 20 min. With potassium permanganate as the etching agent, the adhesive strength could reach 12.08 MPa, which is much higher than the reported maximum adhesive strength (lower than 8.0 MPa). XPS spectra of LCP film indicated that hydrophilic groups were introduced into the LCP surface by etching, creating a nanometer-scale surface roughness and improving the wettability between copper and LCP. SEM and AFM observations revealed that the distinctly increased adhesive strength could be attributed to the improved wetting and the mechanical interlocking effect. The failure mode of Cu-plated LCP film was found to be dependent on the etching time. When the etching time was short, the failure mode of Cu-plated LCP film was mainly adhesive. As the etching time increased, cohesive failure gradually occurred, causing an adhesive/cohesive mixed failure mode.     

熔石英元件HF刻蚀的实验研究

为深入了解熔石英元件化学刻蚀过程,研究了HF刻蚀反应机理、HF刻蚀工艺参数以及刻蚀对表面质量的影响规律。通过控制变量法,获得刻蚀速率随HF浓度、刻蚀温度以及NH4F浓度的变化规律。对刻蚀不同深度后的元件表面粗糙度、形貌、杂质含量以及激光损伤阈值进行了检测,实验结果表明:刻蚀速率受多种因素共同影响,其中HF浓度的促进作用最为显著;刻蚀后的熔石英表面形貌复杂,有横向、纵向、拖尾等形式的划痕,以及坑点、杂质等缺陷,其中横向划痕和纵向划痕占据了缺陷部分的主体,主要杂质铈元素随刻蚀时间的增长不断减少;激光损伤阈值测量实验表明,通过HF刻蚀将元件损伤阈值提高了59.6%。     

CVD金刚石中的氮对等离子体刻蚀的影响

采用非对称磁镜场电子回旋共振等离子体分别对沉积过程中掺氮和未掺氮的化学气相沉积金刚石膜进行了刻蚀研究, 结果表明: 掺氮制备的金刚石膜的刻蚀主要集中在晶棱处, 经过4h刻蚀后其表面粗糙度由刻蚀前的4.761 μm下降至3.701 μm, 刻蚀对金刚石膜的表面粗糙度的影响较小; 而未掺氮制备的金刚石膜的刻蚀表现为晶面的均匀刻蚀, 晶粒坍塌,刻蚀4h后其表面粗糙度由刻蚀前的3.061 μm下降至1.083 μm. 刻蚀导致表面粗糙度显著降低. 上述差别的主要原因在于金刚石膜沉积过程中掺氮导致氮缺陷在金刚石晶棱处富集, 晶棱处电子发射加强, 引导离子向晶棱运动并产生刻蚀, 从而加剧晶棱的刻蚀. 而未掺氮金刚石膜,其缺陷相对较少且分布较均匀 ,刻蚀时整体呈现为 (111) 晶面被均匀刻蚀继而晶粒坍塌的现象. 关键词： 掺氮 金刚石膜 刻蚀 非对称磁镜场     

Self-organized near-field etching of the sidewalls of glass corrugations

Using soda-lime glass with a nano-stripe pattern as a test specimen, we demonstrated self-organized near-field etching with a continuum-wave laser (λ=532 nm) light source. Atomic force microscopy confirmed that near-field etching decreases the flank roughness of the corrugations as well as the roughness of the flat surface.     

Laser etching of transparent materials at a backside surface adsorbed layer

The laser etching using a surface adsorbed layer (LESAL) is a new method for precise etching of transparent materials with pulsed UV-laser beams. The influence of the processing parameters to the etch rate and the surface roughness for etching of fused silica, quartz, sapphire, and magnesium fluoride (MgF₂) is investigated. Low etch rates of 1 nm/pulse and low roughness of about 1 nm rms were found for fused silica and quartz. This is an indication that different structural modifications of the material do not affect the etching significantly as long as the physical properties are not changed. MgF₂ and sapphire feature a principal different etch behavior with a higher etch rate and a higher roughness. Both incubation effects as well as the temperature dependence of the etch rate can be interpreted by the formation of a modified near surface region due to the laser irradiation. At repetition rates up to 100 Hz, no changes of the etch rate have been observed at moderate laser fluences.