Micro-electro-mechanical system (MEMS) and related actuator bumps, methods of manufacture and design structures
View Patent ↗Micro-Electro-Mechanical System (MEMS) structures, methods of manufacture and design structures are provided. The method of forming a MEMS structure includes forming fixed actuator electrodes and a contact point on a substrate. The method further includes forming a MEMS beam over the fixed actuator electrodes and the contact point. The method further includes forming an array of actuator electrodes in alignment with portions of the fixed actuator electrodes, which are sized and dimensioned to prevent the MEMS beam from collapsing on the fixed actuator electrodes after repeating cycling. The array of actuator electrodes are formed in direct contact with at least one of an underside of the MEMS beam and a surface of the fixed actuator electrodes.
1. A method of forming a MEMS structure, comprising:
patterning a wiring layer on a substrate to form fixed actuator electrodes and a contact point;
forming a sacrificial material on the wiring layer;
patterning the sacrificial material with an array of trenches above the wiring layer, the trenches being dimensioned to a predetermined height and width;
filling the array of trenches with material;
forming a MEMS beam above the filled array of trenches and in contact with the material in the array of trenches;
forming additional sacrificial material over the MEMS beam;
forming a lid over the additional sacrificial material over the MEMS beam;
forming at least one vent hole in the lid; and
venting the sacrificial material under the MEMS beam and the additional sacrificial material over the MEMS beam, such that the material within the array of trenches becomes suspended from an underside of the MEMS beam, forming an array of actuator bumps at the predetermined height and width.
2. The method of claim 1 , wherein the array of actuator bumps are in direct contact with and extend from an insulator material forming an underside of the MEMS beam.
3. The method of claim 1 , wherein the array of actuator bumps are formed in alignment with the fixed actuator electrodes under the MEMS beam.
4. The method of claim 1 , wherein the array of actuator bumps are formed in alignment with spaces or openings between the fixed actuator electrodes under the MEMS beam so as to land on the substrate when the MEMS beam is actuated downward.
5. The method of claim 1 , wherein:
the array of actuator bumps are formed in alignment with dummy actuator electrodes in a fixed actuator level under the MEMS beam; and
the dummy actuator electrodes are formed on the wiring layer as one of:
individually electrically floating electrodes; and
connected individually electrically floating electrodes.
6. The method of claim 5 , wherein the individually electrically floating electrodes or the connected individually electrically floating electrodes are biased to a known voltage.
7. The method of claim 1 , wherein the array of actuator bumps are formed in alignment with insulator material between portions of the fixed actuator electrodes.
8. The method of claim 1 , wherein the array of actuator bumps are all formed with a uniform height and width.
9. The method of claim 1 , wherein the array of actuator bumps are formed with differing heights and widths using at least one of different etch rates and masking steps.
10. The method of claim 9 , wherein the actuator bumps farthest away from the contact point are formed deeper than the actuator bumps formed closer to the contact point.
11. The method of claim 1 , wherein the array of actuator bumps are formed under insulator material and between portions of conductor material forming the MEMS beam.
12. The method of claim 1 , wherein an additional array of actuator bumps are formed on the wiring layer, and extend towards the MEMS beam.