Evolution of the structure and hydrogen bonding configuration in annealed hydrogenated a-Si/a-Ge multilayers and layers

► We study hydrogenated amorphous Si/Ge multilayers annealed to form SiGe alloy. ► H is released from Si and Ge atoms on annealing. ► Annealing causes surface blistering. ► Released hydrogen is partially trapped in cavities that form blisters by increasing in size. ► Si di-hydrides are formed on the inner surfaces of the cavities/blisters.