## 1 Introduction
Summarizing the conclusions of this work, it should be noted that in addition to high \(\varepsilon\) and low dielectric losses, tunable elements based on STO films exhibit a nonlinear dependence of the permittivity on the electric field, high response speed, and a weak temperature dependence of the properties at room temperature. A separate challenge is the development of high-power tunable FE microwave elements. One of the most important characteristics of these elements is their ability to operate at a high level of microwave power without distortion of the capacitance and quality factors. These distortions occur under the influence of electrical and thermal effects. Electrical distortions caused by the nonlinearity of the FE material are inevitable in ferroelectric microwave devices. They are successfully used in nonlinear devices or can be minimized in tunable filters and phase shifters [38; 39]. The scale of thermal distortions caused by microwave power dissipation is determined by the thermal conductivity of the dielectric substrate [40]. Today, high-quality strontium titanate films are grown on various mono- and polycrystalline substrates such as MgO [41], LaAlO\({}_{3}\)[19], sapphire [42], alumina [37], and DyScO\({}_{3}\)[26; 27; 28]. Magnesium and aluminum oxides have the best heat-conducting characteristics of the above materials [43; 44]. The thermal conductivity coefficients of MgO and Al\({}_{2}\)O\({}_{3}\) are between the order of 60 and 40 W\(\cdot\)m\({}^{-1}\cdot\)K\({}^{-1}\), respectively, which does not allow them to avoid overheating ferroelectric microwave elements on these substrates [11; 38; 39]. Semi-insulating silicon carbide (SiC) appears to be a promising substrate material that can significantly improve the power characteristics of FE elements. The material has a thermal conductivity coefficient of 500 W\(\cdot\)m\({}^{-1}\cdot\)K\({}^{-1}\), high strength, low dielectric losses [45; 46], and proven production technology. Thus, tunable high Q-factor elements based on strontium titanate films on silicon carbide substrates are potentially promising for high-power microwave applications. Today, a number of works devoted to the growth of FE films on silicon carbide have been published [47; 48; 49; 50]. All of these works consider elements based on BST films, the highest quality factor of which does not exceed 50 at microwaves. Publications devoted to strontium titanate films on silicon carbide are absent in the modern literature. In connection with the above, the objective of this work is to synthesize strontium titanate films of high structural quality on semi-insulating silicon carbide substrates for their further use in powerful high-Q-factor microwave tunable devices. For this purpose, we investigated the relationships between the technological conditions of film deposition, the mechanisms of their nucleation and growth on SiC substrates, and their structural and electrical characteristics. Studies on the growth mechanisms of strontium titanate films were carried out on island structures sensitive to changes in technological parameters. The relationship between the structural characteristics and key technological factors, namely substrate temperature and working gas pressure, was studied using X-ray structural analysis. The electrical characteristics of the films with the best crystal structure were studied using resonance techniques using planar capacitors at microwaves.