An archival optical storage technique based on hydrogen evolution in hydrogenated amorphous silicon (a‐Si:H) is presented. Thin films (∼0.5 &mgr;m) ofa‐Si:H have been prepared by rf glow discharge in SiH4and deposited on a thermally grown oxide pattern formed on float zone ⟨111⟩ crystalline Si (c‐Si) substrates. Replication of the oxide pattern is achieved by ablation of thea‐Si:H layer after annealing. This low‐temperature process produces a predesigned array of circular holes caused by bursting of microbubbles in thea‐Si:H layer. In comparison, the circular holes nucleate randomly on unoxidizedc‐Si.