Reinforcement structures used with a thinned wafer and methods of manufacture are provided. The method includes forming trenches or vias at least partially through a backside of a thinned wafer attached to a carrier wafer. The method further includes depositing material within the trenches or vias to form reinforcement structures on the backside of the thinned wafer. The method further includes removing excess material from a surface of the thinned wafer, which was deposited during the depositing of the material within the vias.