Microprocessing by intense pulsed electron beam

Abstract

Generation of intense electron beams by superposing two discharges, namely, a low-pressure DC glow discharge and a high-current pulsed discharge at pressures and voltages very similar to that of the pseudospark gap devices, has been studied. The small beam diameter, high peak current, and short pulse length are the characteristics of the electron beam generated using this technique. This technique does not require high vacuum facilities, and applications such as microprocessing, X-ray generation, and preionization for high-power lasers are feasible. The electron beam current is in the range of 10-30 A. Microprocessing as drilling tenths of microns diameter holes in different materials such as copper, titanium, and tantalum has been performed. The microstructure of the irradiated materials has been investigated by means of scanning electron microscope (SEM) and atomic force microscope (AFM). Currently, the possibility of processing a matrix of holes is being considered. In this paper, preliminary study regarding the interaction of intense short electron beams with different metallic targets is presented. The electron generator consists of a fast filamentary discharge in low-pressure gases, and the filling gases such as helium, argon, or nitrogen at approximately 0.1 torr pressure are used. Some of the important characteristics of the device for drilling and micromachining are that the targets can be easily changed, and the beam can be deflected by means of a magnetic field. After the initial device characterization, several holes at different experimental conditions were drilled onto the target materials, and the interaction of the beam with these different targets was investigated by means of a scanning electron microscope.