تجزیه و تحلیل شبیه سازی از فیلم های نازک آلومینیوم و اندازه گیری ضخامت فیلم با استفاده از پرتو کم انرژی الکترون

This paper indicates a simulation analysis for estimating the aluminum (Al) thin film thickness measurements by using the low energy electron beam. In order to calculate the Al thickness estimation, the energy of the incident electron beams was varied from 10 to 30 keV, while the thickness of the Al film was varied between 6 and 14 μm. From the simulation results it was found that electron transmittance fraction in 14 μm sample is about nine orders of magnitude more than 6 μm sample at the same incident electron beam energy. Simulation results show that maximum transmitted electrons versus Al layer thickness has a parabolic relation and by using the obtained equation, it is possible to estimate unknown thickness of the thin film Al layer. All calculations here were done by CASINO numerical simulation package.

The study of the physical properties of thin films is important due to its multiple technological applications such as, modern optoelectronic devices, sensors, micro and nano electronic devices [1], [2], [3] and [4]. Aluminum thin films and Al binary and ternary alloys are widely used for electronic and optoelectronic device applications and comprise the majority of the interconnections used in the electronic chipsets [5], [6] and [7]. The physical properties of the Al thin films depend strongly on their microstructure, which can be characterized using different techniques [1] and [8]. After having fulfilled the growing of the film, one of the following tasks is to determine its thickness. Scanning electron microscopy (SEM) is one of the most popularly used tools for thin films characterizing such as thickness measurement, and grain boundary studies. Recently, SEM and related instrument such as energy dispersive X-ray spectrometer (EDS) and Electron Spectroscopy for Chemical Analysis (ESCA) have attracted a lot of interests to research and application in material science and provide increased information from bulk, thin film and coating samples [9], [10] and [11]. But above mentioned techniques cannot be used in general labs and also, for a large area coated thin films, these techniques are too expensive. Most of today's available techniques are restricted to certain type of films and many have difficulties in performing the measurement in situ [7] and [12]. Measurement and estimation of the thin films thickness by using the simple and inexpensive techniques is too important parameter in both industrial and scientific aspects. In this paper, a simulation analysis presented for estimating the Al thin film thickness measurements by using the low energy electron beam. We used CASINO simulation software which developed by Raynald Gauvin et al. at Université de Sherbrooke, Québec, Canada [13], [14] and [15]. This program is a Monte Carlo simulation of electron trajectories in solids, specially designed to simulate the interaction of low energy electron beams with bulk samples and thin foils. This paper indicates a numerical analysis method to estimation of thin film layers which by using the presented experimental set up (see Fig. 1), it is possible to low-cost and in situ thin film thickness measurement. The computation used tabulated Mott elastic scattering cross sections of Czyzewski and stopping powers model from Joy and Luo [14].

This paper indicates a Monte Carlo simulation analysis for Al thin film thickness measurements. Numerical simulations have been done by adjusting parameters such as the electron stopping range, Al layer thickness, and incident electron beam energy. It was found that electron transmittance fraction in 14 μm sample is about nine orders of magnitude more than 6 μm sample at the same incident electron beam energy. Simulation results show that maximum transmitted electrons versus Al layer thickness have a parabolic relation which by using the obtained equation it is possible to estimate unknown thickness of the Al layer.