Estimation of Thermal Stability of Si-SiO₂-W Nanolayered Structures with Infrared Spectrometry

Nanolayered coatings are proposed for use in microelectronic devices where the size/performance ratio is becoming increasingly important, with the aim to achieve existing quality requirements while reducing the size of the devices and improving their ability to perform stably over multiple cycles. Si-SiO₂-W structures have been proposed as a potential material for the fabrication of microelectronic devices. However, before such materials can be implemented in devices, their properties need to be carefully studied. In this study, Si-SiO₂-W nanolayered structures were fabricated and subjected to numerous thermal treatment cycles at 150 °C. A total of 33 heating cycles were applied, resulting in a cumulative exposure of 264 h. The changes in chemical bonds and microstructure were monitored using Fourier Transform Infrared spectrometry (FTIR) and scanning electron microscopy (SEM). The FTIR signal at 960 cm^-1, indicating the presence of W deposited on SiO₂, was selected to characterize the thermal stability during the heating cycles. The estimated signal intensity variation closely resembled the normal inhomogeneity of the nanolayers. The increase in slope intensity was estimated to be 1.7 × 10^-5.