The patterns (or layout), and pattern densities of TSVs described above provide layout of TSVs that could be etched with reduced etch microloading effect(s) and with good within-die uniformity. The patterns and pattern densities of TSVs for different groups of TSVs (or physically separated groups, or groups with different functions) should be fairly close amongst different groups. Different groups of TSVs (or TSVs with different functions, or physically separated TSV groups) should have relatively close shapes, sizes, and depths to allow the aspect ratio of all TSVs to be within a controlled (and optimal) range. The size(s) and depths of TSVs should be carefully selected to optimize the etching time and the metal gap-fill time.