Passive temperature compensation of silicon MEMS devices
The invention relates to MEMS devices. In one embodiment, a micro-electromechanical system (MEMS) device comprises a resonator element comprising a semiconducting material, and at least one trench formed in the resonator element and filled with a material comprising oxide. Further embodiments comprise additional devices, systems and methods.
1. A micro-electromechanical system (MEMS) device comprising:
a resonator element comprising a semiconducting material; and
at least one trench formed in the resonator element and filled with a material comprising oxide.
2. The MEMS device of claim 1 , further comprising:
a cavity; and
an electrode defining at least a portion of the cavity, wherein the resonator element is disposed in the cavity spaced apart from the electrode.
3. The MEMS device of claim 1 , wherein the resonator element is fixed at a first end.
4. The MEMS device of claim 3 , wherein the resonator element is fixed at a second end.
5. The MEMS device of claim 1 , wherein the resonator element and the at least one trench each have a circumference.
6. The MEMS device of claim 5 , wherein the at least one trench comprises a plurality of trench segments spaced apart from each other.
7. The MEMS device of claim 1 , wherein the at least one trench comprises a plurality of trenches spaced apart from each other.
8. The MEMS device of claim 1 , further comprising a cap formed on a first end of the at least one trench.
9. The MEMS device of claim 8 , further comprising a cap layer formed on a second end of the at least one trench.
10. The MEMS device of claim 9 , wherein the trench is lined with a material.
11. The MEMS device of claim 8 , wherein the cap comprises at least one of polysilicon, a metal material, or a conducting material.
12. The MEMS device of claim 1 , wherein the semiconducting material comprises one of silicon or silicon germanium.
13. A micro-electromechanical system (MEMS) device comprising:
a moveable element having a first temperature coefficient of elastic modulus; and
at least one trench formed in the moveable element and filled with a material having a second temperature coefficient of elastic modulus different from the first temperature coefficient of elastic modulus.
14. The MEMS device of claim 13 , wherein the moveable element comprises a semiconducting material and the material having a second temperature coefficient of elastic modulus comprises an oxide.
15. The MEMS device of claim 13 , wherein the moveable element comprises a resonator.
16. The MEMS device of claim 13 , further comprising a cap material deposited over a first end of the at least one trench.
17. The MEMS device of claim 16 , wherein the cap material lines the trench.
18. The MEMS device of claim 16 , wherein the cap material is deposited in a second end of the at least one trench.
19. The MEMS device of claim 16 , wherein the cap material comprises polysilicon.
20. The MEMS device of claim 13 , wherein the moveable element and the at least one trench each have a circumference, and wherein the circumference of the at least one trench is smaller than the circumference of the moveable element.
21. A method comprising:
forming a trench in a moveable portion of a micro-electromechanical system (MEMS) device; and
filling the trench with a material having a temperature coefficient of elastic modulus different from a temperature coefficient of elastic modulus of the moveable portion.
22. The method of claim 21 , further comprising:
depositing a material layer over a first end of the trench.
23. The method of claim 21 , further comprising:
lining the trench with a material layer.
24. The method of claim 21 , further comprising:
causing the moveable portion to resonate; and
determining a resonant frequency of the moveable portion.
25. The method of claim 21 , wherein the device comprises silicon.