Spatial light modulator multi-layer mirror plate
A spatial light modulator having a multi-layer mirror is described.
1. A spatial light modulator device comprising:
a control substrate having an upper portion with a plurality of electrodes connected to functional circuitry;
a support post on the control substrate; and
a mirror plate supported by the support post, the mirror plate having an upper reflective surface, a spacer layer and a lower conductive portion, wherein each of the upper reflective surface, spacer layer and lower conductive portion have a different material composition from one another.
2. The device of claim 1 , wherein:
the lower conductive portion includes a hinge;
a pair of support posts support the hinge; and
the mirror plate is rotatable about the hinge.
3. The device of claim 2 , wherein the support posts include amorphous silicon.
4. The device of claim 1 , wherein:
the spacer layer includes amorphous silicon; and
the lower conductive portion includes a metal.
5. The device of claim 4 , wherein the lower conductive portion includes titanium.
6. The device of claim 4 , wherein the lower conductive portion includes a titanium alloy.
7. The device of claim 4 , wherein the upper reflective surface includes aluminum.
8. The device of claim 4 , wherein the upper reflective layer has a thickness of approximately 400 angstroms or less and is selected from the group of metals consisting of aluminum, gold, and combinations thereof.
9. The device of claim 4 , wherein the lower conductive portion is one of tantalum, tungsten, molybdenum, nickel or their alloys.
10. The device of claim 4 , wherein the lower conductive portion is a silicide of titanium, tantalum, tungsten, molybdenum or nickel.
11. The device of claim 1 , wherein:
the upper reflective layer includes aluminum;
the spacer layer includes amorphous silicon; and
the lower conductive portion includes titanium.
12. The device of claim 1 , wherein the lower conductive portion is titanium, tantalum, tungsten, molybdenum, nickel or an alloy thereof.
13. The device of claim 1 , wherein the spacer layer includes a low temperature deposited material.
14. The device of claim 1 , wherein the mirror plate has a thickness of between about 3000 and 5000 angstroms.
15. The device of claim 1 , wherein the mirror plate has a thickness of between about 1000 and 3000 angstroms.
16. The device of claim 1 , wherein the spacer layer is between about 1000 and 2000 angstroms thick.
17. The device of claim 1 , wherein the spacer layer is between about 2000 and 5000 angstroms thick.
18. The device of claim 1 , further comprising a lubricating layer on the lower conductive portion.
19. A method of forming a spatial light modulator device, comprising:
forming a plurality of electrodes on an upper portion of a control substrate, wherein the electrodes are connected to functional circuitry;
forming a support post on the control substrate; and
forming a mirror plate supported by the support post, wherein forming the mirror plate includes forming an upper reflective surface, a spacer layer and a lower conductive portion, wherein each of the upper reflective surface, spacer layer and lower conductive portion have a different material composition from one another.
20. A method of using a spatial light modulator device, comprising applying a voltage to at least one electrode of the plurality of electrodes of the spatial light modulator of claim 1 , wherein the voltage causes the mirror plate to rotate towards the electrode.