A low cost integration method for a plurality of deep isolation trenches on the same chip is provided. The trenches have an additional n-type or p-type doped region surrounding the trench—silicon interface. Providing such variations of doping the trench interface is achieved by using implantation masking layers or doped glass films structured by a simple resist mask. By simple layout variation of the top dimension of the trench various trench depths at the same time can be ensured. Using this method, wider trenches will be deeper and smaller trenches will be shallower.