MEMS device fabricated on a pre-patterned substrate
View Patent ↗A microelectromechanical systems device fabricated on a pre-patterned substrate having grooves formed therein. A lower electrode is deposited over the substrate and separated from an orthogonal upper electrode by a cavity. The upper electrode is configured to be movable to modulate light. A semi-reflective layer and a transparent material are formed over the movable upper electrode.
1. A method of making an electromechanical systems device, the method comprising:
providing a substrate having a plurality of trenches in a top surface of the substrate; and
forming a moveable electrode layer over the top surface of the substrate and in the trenches, wherein the moveable electrode layer is discontinuous between inside the trenches and outside the trenches such that the moveable electrode layer outside the trenches forms a plurality of moveable electrodes separated from one another.
2. The method of claim 1 , further comprising depositing a sacrificial layer over the top surface of the substrate and into the trenches prior to forming the moveable electrode layer.
3. The method of claim 1 , further comprising forming a stationary electrode layer over the moveable electrode layer, wherein the moveable electrode layer and the stationary electrode layer have a first cavity therebetween.
4. The method of claim 3 , further comprising:
depositing a sacrificial material over the moveable electrode layer prior to forming the stationary electrode layer; and
removing the sacrificial material after forming the stationary electrode layer.
5. The method of claim 3 , wherein the substrate is formed of an opaque material, wherein the moveable electrode layer comprises an at least partially reflective material, and wherein the stationary electrode layer comprises a partially transparent material.
6. The method of claim 1 , wherein providing the substrate comprises embossing the trenches in the substrate.
7. The method of claim 1 , wherein providing the substrate comprises ablating the trenches in the substrate.
8. The method of claim 1 , wherein providing the substrate comprises forming the trenches in the substrate by a molding process.
9. The method of claim 1 , wherein the electromechanical systems device is an interferometric modulator.
10. An electromechanical systems device formed by the method of claim 1 .
11. A method of forming an electromechanical systems device, the method comprising:
providing a substrate having a top surface, wherein a plurality of grooves is formed in the top surface; and
forming a conductive layer over the substrate and inside the grooves such that the conductive layer is discontinuous at the grooves, forming strips of the conductive layer inside the grooves and strips of the conductive layer outside the grooves, wherein the strips of the conductive layer outside the grooves form conductive lines that are isolated from the strips of the conductive layer inside the grooves.
12. The method of claim 11 , wherein the conductive lines form electrodes of the electromechnical systems device.
13. The method of claim 12 , wherein the electrodes comprise moveable electrodes of the electromechnical systems device.
14. The method of claim 12 , wherein the electrodes comprise stationary electrodes of the electromechnical systems device.
15. The method of claim 12 , further comprising depositing a dielectric layer after forming the conductive layer such that portions of the dielectric layer are deposited into the grooves for isolating the strips of the conductive layer inside the grooves from the conductive lines.
16. The method of claim 11 , wherein providing the substrate comprises forming the plurality of grooves in the top surface of the substrate by at least one of embossing, stamping, ablation, molding, and mechanical imprinting.
17. The method of claim 16 , further comprising baking the substrate after forming the grooves to provide at least one of the grooves with a reentrant profile.