The in-depth distribution of the critical temperature in the YBa2Cu3O7film, predicted by our recent modeling of ion modified high-Tcweak links is checked. Removing a surface layer of the film step by step using bromine-ethanol chemical etching, we observed a nonuniform in-depth critical temperature distribution and found that the film inside becomes granular after the modification. This region with reduced connectivity may be responsible for the Josephson properties observed. A new idea for improving these weak links is reported. If two modifications with different ion energy or different ions are used, it is possible to form the conducting channel inside the superconducting film with dimensions independent from variations in the film thickness. These junctions are expected to have lower long time drift. Additionally, the channel is created in the region of the film where the film properties are superior to those near the interface. This should strongly improve the yield of the working device on the chip. ©1997 American Institute of Physics.