Nature is slowly regenerating it by itself. People can make more ozone, but that takes a lot more energy to do it on a planetary scale which we simple do not have access to at the moment. read more
More ozone breaks down than the sun can rebuild. This imbalance comes from the "hole," or thinning, in the ozone layer over Antarctica. Human-produced ozone depleting compounds, like chlorofluorocarbons (CFCs), are doing most of the damage. Complex chemical reactions, which can only take place in Antarctica during the winter and spring, destroy ozone. read more
Yes, the ozone layer is capable of regenerating as regular oxygen is ionized by the ultra-violet and cosmic rays that are entering the earth causing an oxygen ion to form a triatomic bond. However the amount of ozone depleting chemicals entering the atmosphere is destroying the ozone layer faster then it can regenerate, in fact in takes only on CFC molecule to destroy 30000 O3 molecules. read more