Исследование физических характеристик магнетронов с различными мишенями-материалами при замене магнитной системы

<jats:p>В данной статье исследуются различные характеристики магнетронов, в частности получена математическая модель скорости формирования двух материалов с применением данного устройства. Приведены вольт-амперные характеристики процесса распыления при рабочих значениях давления газа в камере, благодаря которым становится возможно контролирование всех факторов эксперимента. Показано влияние магнитной составляющей на внешний вид вольт-амперной характеристики. Сформирована экспериментальная серия образцов из Ti и Al, благодаря которым получены математические модели.</jats:p> <jats:p>Introduction. Self-propagating high-temperature synthesis (SHS) involves a strongly exothermic reaction during the interdiffusion of two or more materials, leading to various reaction products. The energy released by a thin-film multilayer structure undergoing an SHS reaction presents a promising method for attaching silicon chips to packages or surface-mount components to printed circuit boards. Table 1 lists known parameters for the Ti-Al system. Analysis of Table 1 indicates that the Ti-Al pair exhibits sufficient reaction temperature and energy release for use in printed circuit board (PCB) manufacturing. Furthermore, the constituent materials are inexpensive (compared, for example, to NiAl), are easier to deposit via magnetron sputtering (compared to TiB₂), yield conductive reaction products (unlike ZrB₂), and do not outgas during the reaction. Moreover, the properties and deposition techniques for thin films of these metals using vacuum methods are well studied. Owing to these advantages, fabricating a multilayer structure capable of a self-propagating high-temperature synthesis reaction based on Ti and Al via magnetron sputtering represents a promising direction in micro- and nanoelectronics [6]. A key challenge in forming nanometer-scale thin films is determining the deposition rate and identifying the technological factors that influence it. This work aims at investigating various physical characteristics – specifically, the current-voltage characteristics, magnetic field configuration, and a mathematical model of thin film formation in magnetrons following a magnetic system replacement. To achieve this aim, the following tasks were addressed: 1) obtain current-voltage characteristics of the magnetrons to identify operational issues; 2) investigate the magnetic field configuration to stabilize the target sputtering process; 3) deposit an experimental series of Ti and Al thin films and derive mathematical models describing the dependence of the deposition rate on various process factors. Conclusions. 1) The current-voltage characteristics obtained after replacing the magnetic system (Fig. 1b for Ti and Fig. 5b for Al) correspond to optimal magnetron operating conditions across working pressures from 0.5 to 3 Pa. The voltage required to sustain the glow discharge on the target surface decreased from 330–470 V to 230–310 V for Ti and from 330–630 V to 230–330 V for Al, while the maximum current increased from 2 A to 3 A; 2) To reduce the energy impact on the growing film, a type I unbalanced magnetron configuration with a south pole at the center was selected. Following the magnetic system replacement, the magnetic induction at the central south pole increased from 60 mT to 200 mT, and at the peripheral north pole from 15 mT to 80 mT for the Ti target. For the Al target, the magnetic induction at the central south pole increased from 35 mT to 160 mT, and a peripheral north pole with an induction of 35 mT appeared. The emergence of the north pole at the edges is attributed to the use of a soft magnetic steel baseplate. The differences in magnetic induction between the two target materials are also influenced by their physical properties and different thicknesses – 10 mm for Al and 6 mm for Ti; 3) A series of experimental Ti and Al thin film samples were deposited by magnetron sputtering according to the experimental design. Resulting mathematical dependencies of the form given in equations (1) and (2) were obtained. These models are adequate according to the Fisher (F) criterion. The experiments showed that Ti deposits more slowly than Al, making it more sensitive to the gas environment (the model for Al lacks the coefficient α, as it is not significant). The primary reason for the higher deposition rate of Al compared to Ti is the difference in sputter yield, which depends on the physical properties of the materials, the magnetron design, and the process parameters. Under ideal conditions, the sputter yield for Al at an argon ion energy of 300 eV is 0.65 atoms/ion, compared to 0.33 atoms/ion for Ti.</jats:p>