An electronic device (50) having a conductive substrate via (70) extending between a conductor (39) on a rear face (22) and a conductor (58) over the front surface (23) of the substrate (21) includes a multi-layered etch-stop (56, 56-2) beneath the front surface conductor (58). The etch-stop (56, 56-2) permits use of a single etchant to penetrate both the substrate (21) and any overlying semiconductor (44) and/or dielectric (34) without attacking the overlying front surface conductor (58). This is especially important when the semiconductor (44) and dielectric (34) are so thin as to preclude changing etchants when these regions are reached during etching. The etch-stop (56) is preferably a stack (63, 73) of N≧2 pairs (62-i) of sub-layers (62-i1, 62-i2) in either order, where a first sub-layer (62-i1) comprises stress relieving and/or adhesion promoting material (e.g., Ti), and the second sub-layer (62-i2) comprises etch resistant material (e.g., Ni). In a further embodiment, where the device (50) includes field effect transistors (52) having feedback sensitive control gates (30), the etch-stop material (56) is advantageously used to form gate shields (76).