Hydrogen behaviour in amorphous Si/Ge nano-structures after annealing

► We study hydrogenated amorphous Si/Ge superlattices annealed to form SiGe alloy. ► Annealing causes extensive blistering in hydrogenated samples. ► Blisters due to accumulation into bubbles of hydrogen released upon annealing. ► Hydrogen released more easily from Ge layers than from the Si ones. ► The amount of hydrogen in the bubbles is calculated.