Investigation on etching selectivity and microstructure of Ag doped Sb2Te thin film for dry lithography

Dry lithography is a promising micro/nanomanufacturing method owing to its advantages of solution-free, absence of undercut and resist swelling. However, heat-mode resist suitable for dry lithography is less reported. This work reported Ag doped Sb2Te thin film as heat-mode resist, and its etching selectivity and microstructures are investigated in detail. It is found that Ag1.44Sb2.19Te thin film possesses high etching selectivity in CHF3/O2 mixed gases and can act as a heat-mode resist. In order to elucidate the mechanism of high etching selectivity, the microstructures of the Ag doped Sb2Te thin films are analyzed according to XRD, Raman spectra, XPS, and TEM methods. Results implies that the etching selectivity is attributed to the phase separation of Ag1.44Sb2.19Te film and formation of Sb phase after laser exposure, leading to the reduction of etching resistance in CHF3/O2 mixed gases. Besides, the pattern transfers from Ag1.44Sb2.19Te to SiO2 and Si substrates are achieved successfully and the etching selectivity of Si or SiO2 to Ag1.44Sb2.19Te are both higher than 2:1. This work may provide a useful guide for the research of dry lithography without wet development.

ANTENNA UNIT HEAT MODE

The article describes the procedure for calculating the thermal regime of a unit. The unit under study is part of a phased array. The calculation of the thermal regime allows you to verify the operability of the device under a steady thermal regime and to verify that the choice of the method of cooling the structure is correct. The work of the unit is analyzed under conditions of convective heat exchange without forced cooling at the maximum operating (permissible) ambient temperature. The calculation of the thermal regime of the unit is carried out in two stages. At the first stage, the temperature of the unit case is determined when the unit case overheats in the first approximation. The overheating value is determined from the graph. The calculation is carried out under conditions of natural air cooling. At the second stage, the average surface temperature of the heated zone is determined. The greatest heating in the unit is observed in the area occupied by the board with ERE. According to the results of the calculation, a problem was revealed, which consists in the fact that under the given operating conditions of the investigated device, the unit area is heated above the maximum operating temperature of some ERE. The value of the average surface temperature of the heated zone of the unit exceeds the value of the maximum allowable temperature of the least heat-resistant element of the heated zone. This means that it is necessary to use forced air cooling by air convection. The article proposes a solution to the problem of unit overheating, and describes the method of forced air cooling and its design.

Experimental study of operation heat mode of the motor drum of a short belt conveyor

The article presents the results of the experimental study of the motor drum temperature regime of a short belt conveyor. A description of the experimental stand, as well as the equipment used, is presented. The paper describes the test procedure, the initial conditions for testing at each stage. These conditions imply the nature of the change in the initial tension of the belt, the level of conveyor load, design features of the motor drum, in particular the use of a lining or the use of smooth steel shell during testing. The primary results obtained are presented in the form of decoded thermograms of the working area of the motor drum. The generalized processed results of the experimental studies are systematized in the form of graphical dependencies, which are united according to the objects of study: a motor drum, a leaving belt branch, and an entering belt branch. On the basis of the results obtained, the corresponding conclusions are made, which are the law descriptions of the thermal mode of operation with regard to the motor drum, as well as the belt branches in contact with it.