Deposition and surface treatment with intense pulsed ion beams

Intense pulsed ion beams (500 keV, 30 kA, 0.5 μs) are being investigated for materials processing. Demonstrated and potential applications include film deposition, glazing and joining, alloying and mixing, cleaning and polishing, corrosion improvement, polymer surface treatments, and nanophase powder synthesis. Initial experiments at Los Alamos have emphasized thin-film formation by depositing beam ablated target material on substrates. We have deposited films with complex stoichiometry such as YBa₂Cu₃O_7−x and formed diamond-like-carbon films. Instantaneous deposition rates of 1 mm/s have been achieved because of the short ion range (typically 1 μm), excellent target coupling, and the inherently high energy of these beams. Currently the beams are produced in single shot uncomplicated diodes with good electrical efficiency. High-voltage modulator technology and diodes capable of repetitive firing, needed for commercial application, are being developed.     

Printed circuit board as a MEMS platform for focused ion beam technology

By combining low-cost printed circuit board technology and focused ion beam techniques, a simple method has been developed to produce thermal microsensors in a robust package with straightforward electrical connectivity. Two devices have been developed to demonstrate the principle. The first was fabricated using a single step process comprised of FIB deposited platinum. The second device utilised a multistep process using FIB milled thermally evaporated Au on a PCB platform with through-plated vias. The performance of these devices was tested by measuring their thermo-electrical characteristics.     

双向四电子束泵浦KrF主放大器能量沉积

用三维电子输运Ｍｏｎｔｅ－Ｃａｒｌｏ（ＭＣ）方法研究了双向四电子束泵浦ＫｒＦ准分子激光器ＭＯＰＡ系统中主放大器（Ｈ１Ｍ）的能量沉积空间分布。计入了Ｈｉｂａｃｈｉ结构和主膜的影响。对０．５ＭｅＶ的电子，泵浦方向能量沉积基本均匀，而在轴向，因为两窗口间的１４ｃｍ“死区”使得能量沉积呈“马鞍形”，峰谷比为２～３。给出了能量沉积的总量及能量沉积效率与电子束能的关系曲线，为Ｍａｒｘ发生器的二极管电压进行优化设计提供了依据。     

A novel harmless trimming for micro-device with defects and particles in arbitrary geometry by fine milling of focused ion beam

A novel method combining focused ion beam (FIB) milling and image processing for fine trimming of micro-device is introduced in detail in this paper. By using small beam spot size and beam current, selective milling can be realized according to requirement in terms of the difference of gray scale color intensity between defects and useful areas of the FIB images. A magnetoresistive head and ink jet spray head of color printer trimming were described as examples. Trimming result shows that the method is practical and suitable for the fine trimming of micro-device by the selective milling.     

Sputtered copper films with insoluble Mo for Cu metallization: A thermal annealing study

The thermal annealing behavior of Cu films containing insoluble 2.0 at. % Mo magnetron co-sputtered on Si substrates is discussed in the present study. The Cu-Mo films were vacuum annealed at temperatures ranging from 200°C to 800°C. X-ray diffraction (XRD) and scanning electron microscopy (SEM) observations have shown that Cu₄Si was formed at 530°C, whereas pure Cu film exhibited Cu₄Si growth at 400°C. Twins are observed in focused ion beam (FIB) images of as-deposited and 400°C annealed, pure Cu film, and these twins result from the intrinsically low stacking-fault energy. Twins appearing in pure Cu film may offer an extra diffusion channel during annealing for copper silicide formation. In Cu-Mo films, the shallow diffusion profiles for Cu into Si were observed through secondary ion mass spectroscopy (SIMS) analysis. Higher activation energy obtained through differential scanning calorimetry (DSC) analysis for the formation of copper silicide further confirms the beneficial effect of Mo on the thermal stability of Cu film.