Production of thin film of multicomponent inorganic semiconductors under quasi-equilibrium conditions

Abstract

Issues of improving the properties of semiconductor thin film and their reproducibility, as well as improving and reducing the cost of manufacturing technology stimulate research and development of new, advanced methods. Therefore, it is important to optimize the technology of getting reproducible, competitive, high-tech thin films of multicomponent semiconductor compounds with predetermined properties. In the given article it is shown that constructive and technological improvements of a method of thermal spraying in vacuum allow to minimize nonequilibrium conditions of film growth, keeping the advantages of thermovacuum spraying, such as high reproducibility, processability and productivity, a wide range of variations in the synthesis conditions, and, accordingly, the properties of condensates, maximum purity of growth processes, as well as ease of performing and management and cost-effectiveness of the process of getting perfect condensates. For this purpose, we have developed a special construction of a quasi-fusion evaporator and a device for getting semiconductor film in vacuum, as well as a version of a transparent “hot wall”. The resistivity, cross section and geometric dimensions of the cover and the heater of the developed structures were selected so that in the mode of resistive heating of the evaporator temperature gradient due to the difference in their electrical resistance, and, accordingly, the Joule heat of current, in the temperature range 673… 1473 K provided the temperature of the cover 1.1 ... 1.3 times higher than the temperature of the heater. Due to the elevated temperature of the cover, the solid fraction is either repelled on the sublimating (evaporating) surface and the walls of the crucible, or undergoes sublimation (evaporation) from the surface of the cover. Depending on the values of the sputtering rate, the grain size of semiconductor polycrystalline film varied from units of nanometers to several micrometers. Crystallinely ordered films were got at relatively low values of the sputtering rate (0.5...5 nm·s-1). It was set up the technological conditions for getting thin films of multicomponent semiconductors, which ensure the independence of the chemical composition of condensates from the evaporation rate in the wide range from 0.05 to 20 nm·s-1, uniform composition of the gas phase during sublimation, absence of inhomogeneous solids in films, wide range properties of condensates and their high reproducibility.

Aging and degradation of transparent copper iodide thin film electrodes for functional electronic devices

“…One of the most used methods for depositing semiconductor thin films is thermal vacuum sputtering (Bunshah, 1994;Seshan, 2002;Frey & Khan, 2015;Ghanbari & Salavati-Niasari, 2021). The deposition of multicomponent thin films of chalcogenide semiconductors, linear polyacenes, metallophthalocyanines, as well as transparent upper copper iodide electrodes in our research was carried out in serial vacuum sputtering units of previous generations, such as URM 3.279.011 with a steam-oil high-vacuum pump and URM 3.279.047 with a highvacuum ion-heter pump, as well as in a modern combined installation of vacuum sputtering of thin films manufactured by the company "Torr International" (USA) accord-ing to previously described methods , 2020, 2022. It has been experimentally confirmed that high-quality films of organic semiconductors and copper iodide without heterogeneous inclusions, with properties close to single crystals, are deposited at low sputtering speeds.…”

Features of obtaining and properties of thin films organic semiconductors

“…In previous reviews 2020;2022), we provided an analysis of existing methods of applying thin films of inorganic semiconductor materials. In recent decades, thin films of organic semiconductors (OS), or, as they are also called, organic molecular crystals, have attracted special attention in connection with a number of proposals for their use in functional units of modern electronics, and therefore in modern technological equipment.…”