Formation of Er‐germanosilicide films on strained Si 1− x Ge x with different Ge contents

Er‐germanosilicide [Er(Si 1− z Ge z ) 2− y ] films were formed on strained Si 1− x Ge x layers with different Ge contents ( x  = 0.14 and 0.28), and their dependency of formation kinetics on the Ge concentrations was investigated while minimizing the oxygen‐incorporation effect using a TaN capping layer. When a ~30 nm‐thick Er film was used, uniform Er(Si 1− z Ge z ) 2− y films were obtained at an annealing temperature of around 600 °C without their agglomeration and also the strain relaxation of the remaining Si 1− x Ge x layer. The increase in the Ge concentration of the reacting Si 1− x Ge x layer enhanced the formation of the crystalline Er(Si 1− z Ge z ) 2− y film. Furthermore, some enrichment of the Ge content within the Er(Si 1− z Ge z ) 2− y film occurred in comparison with that in the initial and remaining Si 1− x Ge x layers.