MEMS mirror and method of fabrication
First Claim
1. A moveable micromirror comprising:
- a supporting structure;
a flexible post extending from within a trench in the supporting structure such that more than one half of the length of the post is within the trench; and
a table extending radially from the end of the post along a plane generally perpendicular to the post, the table having a reflective surface facing away from the supporting structure, wherein the post is so constructed so as to be sufficiently flexible to allow the reflective surface to be selectively moveable and positionable, with at least two degrees of freedom, when urged by a suitable actuating force.
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Accused Products
Abstract
A moveable micromirror includes a supporting structure, a flexible post extending from the supporting structure, and a table extending radially from the end of the post along a plane generally perpendicular to the post, the table having a reflective surface facing away from the supporting structure. The post, preferably formed of single-crystal silicon, is dimensioned to be sufficiently flexible to allow the reflective surface to be selectively moveable and positionable, with at least two degrees of freedom, when urged by a suitable actuating force. A method of making an array of moveable micromirrors of this type includes deep etching a silicon substrate so as to form posts surrounded by trenches, etching back the surface of the substrate around the posts so as to allow the posts to protrude beyond the surface of the substrate, and affixing a table with a reflective surface thereon to the tops of a plurality of the posts.
50 Citations
23 Claims
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1. A moveable micromirror comprising:
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a supporting structure;
a flexible post extending from within a trench in the supporting structure such that more than one half of the length of the post is within the trench; and
a table extending radially from the end of the post along a plane generally perpendicular to the post, the table having a reflective surface facing away from the supporting structure, wherein the post is so constructed so as to be sufficiently flexible to allow the reflective surface to be selectively moveable and positionable, with at least two degrees of freedom, when urged by a suitable actuating force. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A moveable micromirror for selectively directing optical beams, the micromirror comprising:
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a substrate formed of a first single crystal of silicon;
a post extending from within a moat in a surface of the substrate, the post being formed of the single crystal of silicon;
a table fixed along a plane generally perpendicular to and supported by the post and having a reflective surface facing away from the surface of the substrate and a second surface facing the surface of the substrate, the distance from the surface of the substrate to the second surface of the table being less than the length of the post; and
an actuator positioned on the surface of the substrate adjacent the second surface of the table and structured so as to be able to selectively position the table by applying an actuating force to the table wherein the post is sufficiently flexible to allow the reflective surface to be selectively moveable and positionable by the actuator. - View Dependent Claims (15, 16)
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17. A method of making an array of moveable micromirrors, the method including:
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deep etching a silicon substrate so as to form posts surrounded by trenches;
etching back the surface of the substrate around the posts so as to allow the posts to protrude beyond the surface of the substrate; and
affixing a mirror to the top of a plurality of the posts along a plane generally perpendicular to the posts. - View Dependent Claims (18, 19, 20, 21, 22, 23)
bonding a wafer to the tops of the plurality of the posts;
depositing one or more reflective layers on the surface of the wafer opposite the posts; and
deep-etching the wafer to separate the wafer into individual mirrors affixed to the top of each post of the plurality of the posts.
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19. The method of claim 18 wherein the step of affixing a mirror to the top of a plurality of the posts further includes, before the step of bonding a wafer to the tops of the plurality of the posts, the step of forming a removable layer on the substrate, and wherein the step of bonding a wafer to the tops of the plurality of the posts includes positioning the wafer in contact with the tops of the posts and in contact with the removeable layer.
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20. The method of claim 19 wherein the removeable layer is a layer of photoresist.
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21. The method of claim 19 wherein the step of bonding a wafer to the tops of the plurality of the posts includes etching notches in the wafer and aligning the notches with the plurality of the posts such that the plurality of the posts are positioned within the notches and are bonded to the wafer in the notches.
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22. The method of claim 18 wherein the step of deep etching the wafer to separate the wafer into individual mirrors includes deep reactive ion etching.
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23. The method of claim 17 wherein the step of deep etching the silicon substrate includes deep reactive ion etching.
Specification