We report the formation and blistering of GaAsN nanostructure layers induced by nitrogen ion implantation into GaAs followed by high-temperature rapid thermal annealing. The GaAsN nanostructure layers consist of zincblende GaN-rich GaAsN nanostructures in an amorphous matrix, apparently formed near the depth of maximum ion damage. Cross-sectional transmission electron microscopy reveals a series of nanometer-sized cavities near the depth of maximum nitrogen concentration, suggesting the formation of nitrogen gas bubbles during annealing. The nitrogen bubbles coalesce and push away the GaAsN nanostructure layer, forming micrometer-sized blisters. The simultaneous formation and blistering of GaAsN nanostructure layers may provide an opportunity for the integration of the nanostructure layers with a variety of substrates. (C) 2004 American Vacuum Society.