Enclosed cavity structures

1. A cavity structure, comprising:

a destination substrate;

a cavity substrate comprising a substrate surface, wherein the cavity substrate adhered to and non-native to the destination substrate;

a cavity extending into the cavity substrate, the cavity having a cavity bottom and one or more cavity walls;

a cap disposed on a side of the cavity opposite the cavity bottom; and

at least a portion of a tether physically attached to and extending from less than all of a width of a side of the cavity substrate,

wherein the cavity substrate, the cap, and the one or more cavity walls form an enclosed cavity enclosing a volume and the tether is external to the enclosed cavity.

2. The cavity structure of claim 1 , wherein the one or more cavity walls extend from the substrate surface in a direction opposite the cavity bottom.

3. The cavity structure of claim 1 , wherein the cap comprises a portion of the one or more cavity walls.

4. The cavity structure of claim 1 , wherein the cap is adhered to the one or more cavity walls or to the substrate surface.

5. The cavity structure of claim 1 , comprising at least a portion of a cap tether physically attached to the cap, wherein the cap tether is broken.

6. The cavity structure of claim 1 , wherein the cap is a separate structure from the cavity substrate.

7. The cavity structure of claim 1 , wherein the cap has a cap internal side facing the cavity and all of the cap internal side is substantially planar extending over the cavity from the cavity walls of the cavity substrate.

8. The cavity structure of claim 1 , comprising a component disposed in the cavity.

9. The cavity structure of claim 8 , comprising at least a portion of a component tether attached to the component, wherein the component tether is broken or separated.

10. The cavity structure of claim 8 , wherein the component has a component surface on a side of the component opposite the cavity bottom, and wherein the component surface is substantially in a common plane with or extends above the substrate surface.

11. The cavity structure of claim 8 , comprising a plurality of components disposed within the cavity.

12. The cavity structure of claim 1 , wherein the cap comprises a contact portion in contact with the one or more cavity walls or substrate surface, a cap wall portion extending away from the contact portion and substrate surface, and a top portion on and in contact with the cap wall portion.

13. The cavity structure of claim 1 , wherein the one or more cavity walls are at a non-perpendicular angle to the substrate surface.

14. The cavity structure of claim 1 , wherein the cavity bottom farthest from the substrate surface forms a line.

15. The cavity structure of claim 8 , wherein the cavity substrate comprises an anisotropically etchable material or a material that is differentially etchable from the component.

16. The cavity structure of claim 1 , wherein the cavity substrate has a substrate area, the cap has a cap area, and the cap area is less than the substrate area.

17. The cavity structure of claim 8 , wherein the destination substrate is a semiconductor substrate comprising a circuit electrically and/or optically connected to the component.

18. The cavity structure of claim 1 , wherein the at least a portion of the tether is a broken or separated tether.

19. The cavity structure of claim 1 , wherein the tether extends less than half of a width of a side of the cavity substrate.