Described are structures useful in microelectronic or MEMS devices such as atomic clocks, sensors, and RF switches, wherein a first material is deposited onto a substrate to define a first material area of coverage and a second material is deposited over the first material area of coverage to define a second material area of coverage that includes the first material area of coverage and that additionally includes area that surrounds the first material area of coverage, such that the first material is enclosed by the second material over the entire area and past the edges of the first material.