Degradation of Ag/Si multilayers during heat treatments

TL;DR

This study investigates the microstructural stability and degradation mechanisms of Ag/Si multilayers during heat treatments, revealing stability up to 523K and degradation processes involving grain growth and silicon diffusion at higher temperatures.

Contribution

It provides detailed insights into the thermal stability and degradation pathways of Ag/Si multilayers, which were previously not well characterized.

Findings

Ag/Si multilayers stable up to 523K for 10h

Microstructural changes occur above 600K

Degradation involves grain growth, groove formation, and silicon diffusion

Abstract

Microstructure changes during annealing of nano-crystalline silver and amorphous silicon multilayers (Ag/a-Si) have been studied by X-ray diffraction and transmission electron microscopy. The dc-magnetron sputtered Ag/a-Si multilayers remained stable even after annealing at 523K for 10h, and microstructural changes occurred only above 600K. The degradation of Ag/a-Si multilayers can be described by the increase of size of Ag grains, formation of grooves and pinholes at Ag grain boundaries and by the diffusion of silicon atoms through the silver grain boundaries and along the Ag/a-Si interfaces. This results in thinning of a-Si layers, and in formation of Ag granulates after longer annealing times.