Display apparatus and methods for manufacture thereof
Display devices incorporating shutter-based light modulators are disclosed along with methods of manufacturing such devices. The methods are compatible with thin-film manufacturing processes known in the art and result in displays having lower power-consumption.
1. A method of forming a spatial light modulator including a shutter supported by a compliant beam, the method comprising:
forming a mold on a substrate, wherein the mold includes a lower horizontal surface, an upper horizontal surface and a wall;
depositing a beam material on the lower horizontal surface and the wall of the mold;
removing the beam material deposited on the lower horizontal surface of the mold while leaving the majority of the beam material deposited on the wall of the mold in place to form the compliant beam;
forming the shutter coupled to the compliant beam; and
removing the mold, thereby releasing the shutter and remaining beam material.
2. The method of claim 1 , wherein the lower horizontal surface of the mold comprises a top of a first sacrificial layer.
3. The method of claim 2 , wherein removing the mold comprises removing the first sacrificial layer.
4. The method of claim 2 , wherein the mold wall comprises a second sacrificial layer.
5. The method of claim 2 , wherein removing the mold comprises removing the second sacrificial layer.
6. The method of claim 1 , wherein removing the beam material comprises applying an anisotropic etch to the beam material.
7. The method of claim 6 , comprising applying an electric potential to the substrate to control the direction of the anisotropic etch.
8. The method of claim 1 , wherein the depositing of the beam material connects the beam material to an anchor disposed on the substrate.
9. The method of claim 1 , wherein the depositing of the beam material connects the beam material to an anchor deposited on a layer of material deposited beneath the lower horizontal surface of the mold.
10. The method of claim 9 , wherein the depositing of the beam material establishes an electrical connection between the beam material and the anchor.
11. The method of claim 1 , wherein forming the shutter comprises depositing a shutter layer on the upper horizontal surface of the mold such that the shutter layer is connected to the beam material.
12. The method of claim 11 , wherein the shutter layer comprises amorphous silicon.
13. The method of claim 11 , wherein the shutter layer is formed from a material other than the beam material.
14. The method of claim 11 , wherein the shutter layer is formed from the same material as the beam material.
15. The method of claim 14 , wherein the beam material and the shutter layer together comprise a composite of a plurality of layers.
16. The method of claim 15 wherein the composite comprises at least 1 layer of amorphous silicon and at least one layer of a metal.
17. The method of claim 15 wherein the plurality of layers yields an unbalanced level of stress in the compliant beams.
18. The method of claim 1 , wherein the mold wall is substantially normal to the substrate.
19. The method of claim 1 , wherein the beam material is deposited on the wall of the mold to have a thickness of less than 2 about microns.
20. The method of claim 1 , wherein the beam material is deposited on the wall of the mold to have a thickness of less than about 1.5 microns.
21. The method of claim 1 , wherein the beam material is deposited on the wall of the mold to have a thickness of less than about 1.0 microns.