离子注入技术改性聚合物薄膜的研究进展

离子注入技术改性聚合物薄膜在电子及电器工程中有着巨大的潜在应用价值。综述了近年来聚合物薄膜经离子注入后在导电性能,光学性能,导磁性能及表面力学机械性能等方面的最新进展。分析了注入离子与聚合物相互作用的物理过程,并指出了该领域存在的问题及发展方向。     

离子注入改性聚[2-甲氧基-5-(3''''-甲基)丁氧基]对苯乙炔微观结构与性能

采用低能氮正离子(N )对π共轭高分子聚[2-甲氧基-5-(3'-甲基)丁氧基]对苯乙炔(MMB-PPV)薄膜进行离子注入改性,注入剂量为9.6×1016 ions/cm2,能量为30 keV.利用红外光谱、紫外-可见吸收光谱、X射线衍射、透射电镜及热失重等手段对离子注入改性MMB-PPV薄膜的微观结构及热学性能进行研究.红外光谱显示,注入后分子侧链烷氧取代基的C-H振动峰强度减弱,同时在3442、1622 cm-1等处出现了N-H键的振动峰;薄膜的紫外-可见吸收光谱向长波方向移动,且在可见光区范围内的吸收强度增加;离子注入使聚合物分子链排列更加规整,取向度明显增大,结晶性能大大改善;经过离子注入后,聚合物材料的初始分解温度由未注入时的245.64 ℃提高至280.52 ℃,分子的热稳定性能显著增强.     

离子注入聚合物表面改性的研究

离子注入聚合物材料表面改性有着独特的优越性。综述了离子注入技术对聚合物表面的机械性能、电学性能、光学性能和磁学性能等方面改性的最新研究与应用进展。     

离子注入对聚合物材料表面改性的研究与应用进展

离子注入对聚合物材料表面改性有着独特的优越性,文中介绍离子注入技术在聚合物材料表面的力学性能、电学性能、光学性能、生物相容性能等方面改性的最新研究与应用进展。     

低能离子注入对聚吡咯甲烯的改性

利用低能氮离子对聚[(3乙酰基吡咯-2,5-二)对二甲氨基苯甲烯](Papdmabeq)薄膜进行了离子注入改性(注入能量为10～35 keV、剂量为1.2×1016～2.2×1017ions/cm2),研究了与材料三阶非线性极化率相关的物理量的变化规律.结果表明,氮离子注入使Papdmabeq薄膜的光电特性都发生了显著变化.适当能量和剂量的氮离子注入Papdmabeq薄膜后,薄膜中导电岛的数量增加,在聚合物分子链间形成了大的导电区域,导致其电导率显著提高.当注入离子的能量为25 keV、剂量为2.2×1017ionS/cm2时,Papdmabeq薄膜的电导率为9.2×10-4S/cm,比本征态Papdmabeq的电导率提高了5个数量级,且离子注入后薄膜电导率的环境稳定性优于经碘掺杂的Papdmabeq.氮离子注入可以使这种聚合物薄膜在可见光范围内的光吸收大幅度提高,使共轭程度得到显著增强.当注入离子的能量为35 keV、剂量为2.2×1017ions/cm2时,Papdmabeq的光学禁带宽度(Eg)由1.626 eV降低到1.340 eV.     

铅离子注入对玻璃表面ITO膜性能的影响

采用离子注入技术将铅离子注入到ＩＴＯ薄膜玻璃中,用分光光度计,四探针测试仪,硬度计等测定了ＩＴＯ膜注入前后的光学性能,电学性能、机械性能和化学稳定性。结果表明注入后光学、电学性能有所下降,而机械性能和化学稳定性有明显提高。这说明离子注入提高ＩＴＯ薄膜玻璃的耐磨损性和在有腐蚀性气氛下的稳定性。     

离子注入PET薄膜导电性能及机理的研究

主要研究了Ar~+、As~+离子注入PET薄膜后对其导电性能的影响及其导电机理。在PET膜上分别注入了不同种类、不同剂量的离子,测定了其注入后的表面电阻率,研究了注入离子后薄膜表面电阻率与温度的关系,根据注入前后的FTIR-ATR谱图及有关理论对其导电机理进行了初步探讨。结果表明,随离子注入的种类不同、剂量的变化、温度的升降,PET膜的表面电阻率呈规律性变化。根据薄膜结构分析初步确认离子注入PET薄膜主要是离子导电。     

固体润滑轴承用9Cr18不锈钢离子注入与磁控溅射改性真空摩擦学研究

为了提高空间固体润滑滚动轴承耐磨寿命,采用全方位离子注入和磁控溅射技术对空间固体润滑轴承用9Cr18材料进行耐磨减摩表面改性研究。首先对9Cr18不锈钢试样表面注入N+、Ti+、Ti++N+,对离子注入后试样采用磁控溅射技术沉积MoS2-Ti薄膜。通过测试注入前后试样粗糙度及硬度,评价不同注入离子及无离子注入不同基底材料下溅射MoS2-Ti薄膜的附着力、真空摩擦学、薄膜磨损率等性能。结果表明离子注入通过提高9Cr18不锈钢基底硬度,能够提高复合改性后9Cr18不锈钢材料真空摩擦学性能20%。     

离子注入改善纳米二氧化钛薄膜光催化性能

利用直流磁控反应溅射技术在玻璃衬底上制备了透明的纳米TiO2光催化薄膜。利用离子注入技术将Sn离子注入到TiO2表面以提高其光催化活性。用X射线衍射（XRD）、X射线光电子谱（XPS）以及UV－VIS分光光度计对薄膜进行结构与性能表征。Sn离子注入后的薄膜具有更高的光催化活性，这是因为在TiO2和SnO2半导体的复合体系中，电子－空穴对的分离变得更加有效，从而提高了其催化性能。     

离子注入技术提高聚合物导电性

离子注入已成为生产集成电路用半导体的掺杂方法,最近,这种掺杂技术已发展到能提高某些共轭聚合物(包括聚乙炔、聚硫氮化物和聚喹啉)的导电性,且所有这些物质的导电性都能达到半导体的水平。虽然离子注入技术还有些缺点,但已被认为是生产带有导电聚合物薄膜的微电子装置的理想方     

Decrease in work function of boron ion-implanted ZnO thin films

We have fabricated boron ion-implanted ZnO thin films by ion implantation into sputtered ZnO thin films on a glass substrate. An investigation of the effects of ion doses and activation time on the electrical and optical properties of the films has been made. The electrical sheet resistance and resistivity of the implanted films are observed to increase with increasing rapid thermal annealing (RTA) time, while decreasing as the ion dose increases. Without any RTA process, the variation of the carrier density is insensitive to the ion dose. With the RTA process, however, the carrier density of the implanted films increases and approaches that of the un-implanted ZnO film as the ion dose increases. On the other hand, the carrier mobility is shown to decrease with increasing ion doses when no RTA process is applied. With the RTA process, however, there is almost no change in the mobility. We have achieved the optical transmittance as high as 87% within the visible wavelength range up to 800 nm. It is also demonstrated that the work function can be engineered by changing the ion dose during the ion implantation process. We have found that the work function decreases as the ion dose increases.     

C60 Films Formed by Ionized Cluster Beam Deposition: Structure and Doping by Ion Implantation

C₆₀ films were formed on a variety of substrates by ionized cluster beam (ICB) technique. Their structure was found to depend on the acceleration voltages and substrate. Then the Coo films were implanted by P⁺-ions with doses from 0—2×10¹⁴ ion/cm². The in situ measurement of electrical conductivity revealed an abrupt decrease of three orders in resistance. The temperature coefficient of resistivity of the P⁺-ion implanted C₆₀ film remained in a negative value.     

Graphene synthesis by ion implantation

We demonstrate an ion implantation method for large-scale synthesis of high quality graphene films with controllable thickness. Thermally annealing polycrystalline nickel substrates that have been ion implanted with carbon atoms results in the surface growth of graphene films whose average thickness is controlled by implantation dose. The graphene film quality, as probed with Raman and electrical measurements, is comparable to previously reported synthesis methods. The implantation synthesis method can be generalized to a variety of metallic substrates and growth temperatures, since it does not require a decomposition of chemical precursors or a solvation of carbon into the substrate.     

Turning an organic semiconductor into a low-resistance material by ion implantation

We report on the effects of low energy ion implantation on thin films of pentacene, carried out to investigate the efficacy of this process in the fabrication of organic electronic devices. Two different ions, Ne and N, have been implanted and compared, to assess the effects of different reactivity within the hydrocarbon matrix. Strong modification of the electrical conductivity, stable in time, is observed following ion implantation. This effect is significantly larger for N implants (up to six orders of magnitude), which are shown to introduce stable charged species within the hydrocarbon matrix, not only damage as is the case for Ne implants. Fully operational pentacene thin film transistors have also been implanted and we show how a controlled N ion implantation process can induce stable modifications in the threshold voltage, without affecting the device performance.     

Material properties and growth control of undoped and Sn-doped In2O3 thin films prepared by using ion beam technologies

Undoped (IO) and Sn-doped In₂O₃ (ITO) films have been deposited on glass and polymer substrates by an advanced ion beam technologies including ion-assisted deposition (IAD), hybrid ion beam, ion beam sputter deposition (IBSD), and ion-assisted reaction (IAR). Physical and chemical properties of the oxide films and adhesion between films and substrates were improved significantly by these technologies. By using the IAD method, non-stoichiometry and microstructure of the films were controlled by changing assisted oxygen ion energy and arrival ratio of assisted oxygen ion to evaporated atoms. Relationships between structural and electrical properties in ITO films on glass substrates were intensively investigated by using the IBSD method with changing ion energy, reactive gas environment, and substrate temperature. Smooth-surface ITO films (R_rms ≤ 1 nm and R_p-v ≤ 10 nm) for organic light-emitting diodes were developed with a combination of deposition conditions with controlling microstructure of a seed layer on glass. IAR surface treatment enormously enhanced the adhesion of oxide films to polymer substrate. The different dependence of IO and ITO films' properties on the experimental parameters, such as ion energy and oxygen gas environment, will be intensively discussed.     

He implantation for improved tribological performance in Au electrical contacts

This paper describes the role of He ion implantation on the friction, wear, electrical contact resistance (ECR), and near surface microstructure of Au films. The films were deposited by e-beam evaporation and implanted with He under two different conditions. Electrical contact resistance and friction data were collected simultaneously, while sliding a Au-Cu alloy pin on He ion implanted Au films. Results showed that friction coefficients were reduced from ~1.5 to ~0.5 and specific wear rates from ~4 × 10^?3 to ~1 ×10^?4 mm³/N m (both versus un-implanted samples) without a significant change in sliding ECR (~16 mΩ) as a result of He ion beam implantation. Subsurface microstructural changes due to tribological stress and the passing of current were analyzed using site-specific cross-sectional TEM. The implantation of He by itself did not induce changes to the grain size or crystallographic texture of e-beam Au. However, frictional contact during ECR testing of low energy He implanted films resulted in the formation of stable equiaxed nanocrystalline grains and the growth and redistribution of cavities beneath the wear surface. Plastic deformation as evidenced by transfer of Au to the pin during frictional contact was significantly reduced as a result of implantation. This was hypothesized to be a result of Orowan-like hardening due to He implantation.     

Turning an organic semiconductor into a low-resistance material by ion implantation

Abstract

We report on the effects of low energy ion implantation on thin films of pentacene, carried out to investigate the efficacy of this process in the fabrication of organic electronic devices. Two different ions, Ne and N, have been implanted and compared, to assess the effects of different reactivity within the hydrocarbon matrix. Strong modification of the electrical conductivity, stable in time, is observed following ion implantation. This effect is significantly larger for N implants (up to six orders of magnitude), which are shown to introduce stable charged species within the hydrocarbon matrix, not only damage as is the case for Ne implants. Fully operational pentacene thin film transistors have also been implanted and we show how a controlled N ion implantation process can induce stable modifications in the threshold voltage, without affecting the device performance.     

Study of the substrate treatment effect on initial growth of indium tin-oxide films on polymer substrate using in situ conductance measurement

Changes in the initial growth mode of ion beam sputtered indium tin oxide (ITO) films on polycarbonate (PC) substrates were investigated by an in situ measurement of electrical conductance. The PC substrates were irradiated with l keV Ar ions in an oxygen environment (ion assisted reaction: IAR), prior to the film deposition for changing the surface energy. The electrical conduction modes in ITO films were discussed in terms of the film thickness and the surface energy of PC substrates. It was found that, in the initial part of the film growth, ITO nucleation density increased with the increase of the surface energy of PC. The change of the growth mode was discussed in both viewpoints of thermodynamics and atomic kinetics theories and verified by AFM (atomic force microscope) observations. Thermal stability of ITO films was investigated to observe the effect of the growth mode change by IAR pre-treatment of polymer substrate.     

Electrical stability of polyimide siloxane films for interlayer dielectrics in multilevel interconnections

Electrical stability of a polyimide siloxane (PSI) film for ultra-large scale integrated circuit (ULSI) multilevel interconnections is studied. The PSI films, modified by p-aminophenyltrimethoxysilane (APTMS), are designed to have three-dimensional polymer structures through Si–O bonds. It has been revealed that the PSI films are more stable in electrical properties at higher temperatures than 150°C, as compared to the conventional polyimide (PI) films. The electrical conduction mechanism study for the PSI films has revealed that Schottky emission is dominant. Barrier height φ_B obtained from the electrical property for the PSI film was 0.460 eV in the temperatures ranging from 25–250°C. On the other hand, barrier height of 0.422 eV at lower temperatures than 150°C and activation energy of 1.09 eV at higher temperatures than 150°C were obtained for the conventional PI film. The difference in polymer structure is very sensitive to the electrical conduction at high temperature, due to sodium ion migration. The ideal band diagrams of metal-insulator-semiconductor (MIS) structures were also discussed. The optical band gaps for PSI and conventional PI films were 3.320 eV and 3.228 eV, respectively. This result suggests that the band gap of PI films can be enlarged by modification with Si–O components. The differential barrier height between the PSI and conventional PI films is 0.038 eV, and is close to the difference in half of optical band gaps (0.046 eV).     

Some preliminary studies of the structure of ion bombarded thin films

The paper describes preliminary electron microscopic and diffraction studies of ion implanted and recoil atom implanted thin films. It is shown that oxygen implanted aluminum films form complex cermets consisting of polycrystalline aluminium islands in an amorphous dielectric matrix.The dielectric consists of compounds made up of both substrate and film elements and the implanted oxygen. It has also been shown that oxygen implanted titanium thin films form cermet structures of crystalline TiO in an amorphous dielectric probably containing TiO₂ and compounds of the silica substrate. The structure of silicon oxide films recoil implanted with silver from an argon bombarded silver over layer has been studied. It is shown that the recoil implanted material forms discrete clusters within the substrate and that argon entering the silicon oxide forms bubbles. A recoil implantation coefficient of 1.1 silver atoms per incident argon ion has been measured.