mems devices not shown along with the metrology structure 10 for the purposes of illustration fig1 comprises only the metrology structure 10 for example the metrology structure 10 may cover an area of approximately 1 on the substrate 12 with the real mems device covering approximately 99 on the substrate 12 these percentages may of course vary in one embodiment the substrate 12 used can be a silicon wafer or glass for example when the fabrication of the mems device is finished the metrology structure 10 can be left on the substrate 12 or diced away during a chip dicing process referring to fig2 in one embodiment the third layer 18 of the metrology structure 10 comprises a third portion 22 of a member disposed in a third portion 24 of the cage 13 in one embodiment the third portion 22 of the member comprises a post 23 shown in fig5 and 6 and the third portion 24 of the cage 13 comprises structures such as tabs 26 and posts 28 according to one embodiment the third portion 24 of the cage of the layer 18 comprises four tabs 26 and four posts 28 during the fabrication of the metrology structure 10 prior to the deposition of the third layer 18 a sacrificial material not shown is patterned with holes corresponding to the post 23 and the posts 28 in such a way that when the third layer 18 is deposited the post 23 and the posts 28 are formed the post 23 and the posts 28 act as.