Micro-electro-mechanical system (mems) structures and design structures

A method comprising:

• forming a first metal layer on an at least a first insulator layer coating an underlying first sacrificial material;
• forming a second insulator layer on the first metal layer;
• forming a second metal layer on the insulator layer;
• forming a third insulator layer on the second metal layer;
• forming a mask on the third insulator layer to protect portions of the third insulator layer, the second metal layer, the second insulator layer, the first insulator layer and the first metal layer, wherein an opening in the mask partially overlaps with the underlying first sacrificial material;
• in single removal process, removing exposed portions of the first insulator layer, the second insulator layer, and third insulator layer, and the first metal layer and the second metal layer, to form a beam structure, and to expose the overlapped portion of the underlying first sacrificial material;
• forming a second sacrificial material over the beam structure and in contact with the exposed portion of the underlying first sacrificial material;
• providing a lid on the second sacrificial material;
• and
• venting, through the lid, the second sacrificial material and the underlying first sacrificial material to form an upper and lower chamber about the beam structure.