METHOD OF FABRICATING REFLECTIVE SPATIAL LIGHT MODULATOR HAVING HIGH CONTRAST RATIO
First Claim
1. A method for fabricating a reflecting pixel, the method comprising:
- providing a silicon layer bearing a conducting layer and supported by an underlying post over a CMOS substrate;
etching through the conducting layer and the silicon layer in gaps of a first photoresist mask to define openings adjacent to a moveable hinge portion in the silicon layer;
depositing a reflecting material within via holes defined by a second photoresist mask patterned over the conducting layer; and
removing the second photoresist mask to leave the reflecting material supported over the conducting layer and hinge by projections at the former location of the via holes.
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Accused Products
Abstract
The contrast offered by a spatial light modulator device may be enhanced by positioning nonreflective elements such as supporting posts and moveable hinges, behind the reflecting surface of the pixel. In accordance with one embodiment, the reflecting surface is suspended over and underlying hinge-containing layer by integral ribs of the reflecting material defined by gaps in a sacrificial layer. In accordance with an alternative embodiment, the reflecting surface is separated from the underlying hinge by a gap formed in an intervening layer, such as oxide. In either embodiment, walls separating adjacent pixel regions may be recessed beneath the reflecting surface to further reduce unwanted scattering of incident light and thereby enhance contrast.
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Citations
20 Claims
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1. A method for fabricating a reflecting pixel, the method comprising:
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providing a silicon layer bearing a conducting layer and supported by an underlying post over a CMOS substrate;
etching through the conducting layer and the silicon layer in gaps of a first photoresist mask to define openings adjacent to a moveable hinge portion in the silicon layer;
depositing a reflecting material within via holes defined by a second photoresist mask patterned over the conducting layer; and
removing the second photoresist mask to leave the reflecting material supported over the conducting layer and hinge by projections at the former location of the via holes. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for fabricating a reflecting pixel, the method comprising:
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providing a silicon layer supported by an underlying post over a CMOS substrate;
forming a dielectric layer over the silicon layer;
etching through the dielectric layer and the silicon layer in gaps of a first photoresist mask to define openings adjacent to a moveable hinge portion in the silicon layer;
removing the dielectric layer over the moveable hinge;
forming photoresist material within the openings;
depositing a reflecting material over the dielectric and the photoresist material; and
removing the photoresist material to leave the reflecting material separated from the moveable hinge by a space. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15)
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16. A reflecting structure comprising
a CMOS substrate comprising an electrode; -
a first post and a second post each of the first post and the second post being coupled to the CMOS substrate wherein the first post and the second post overlie the CMOS substrate;
a moveable stack overlying each of the first post and the second post the moveable stack comprising;
a silicon layer defining;
a moveable hinge portion extending along a diagonal line between the first post and the second post; and
a mirror support portion;
a plurality of supporting structures coupled to the mirror support portion; and
a reflecting surface supported by and overlying the plurality of supporting structures wherein the reflecting surface is free from contact with the moveable hinge portion. - View Dependent Claims (17, 18, 19, 20)
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Specification