Ozone layer is at a height of 50 km above the surface of Earth. If we artificially create ozone by spending a huge sum of money, then also it can't reach that level and will break down into different compounds on its way. There is a chance that it forms a layer of ozone on the surface itself causing smog which affects human life by causing diseases like asthma and cataracts. The ozone holes will recompose itself but only if we reducecfc, hcfc, bfc, etc emmision.
Ozone layer is not constant. The ozone in the layer continuously forms and continuously breaks down. The emission of CFC’s had increased the rate of its breakdown which led to its depletion in the past.
So if we consider creating ozone artificially, then it has to be created continuously. Also a way of putting the artificially created ozone in the ozone layer has to be found. The cost that will be incurred in generating and placing ozone in ozone layer will be tremendous and obviously unfeasible. There will also be other negative environmental effects that will follow the production of artificial ozone. It is best that the ozone layer is left alone and the CFC emission is reduced so that the layer fills itself naturally.