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US 2003/0156261 A1Published application
DMD pixel with small-rotated-moved via2 to reduce beam-electrode shorts
AssigneeTexas Instruments Incorporated
InventorsJames D. Huffman, Brian K. Dodge, Mark K. Fletcher
Life of this patent
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Abstract
A digital micromirror device with an optimized beam dimple formed over the via2 to provide process margin by increasing the clearance between the beam and the address electrode, thus reducing shorting between the two. This approach assures that when the beam tilts, it will land on its tips prior to making contact between the beam and address electrode, which are at different potentials. Beam dimple optimization is controlled by the characteristics of the via2 located on the lower metal-3 layer of the device.
Claims16
A digital micromirror device, comprising:
- a substrate layer, said substrate layer comprised of a pixel memory array;
- an oxide isolation layer on said memory array;
- a metal-3 layer on said oxide layer, said metal-3 layer comprised of an array of positive and negative address electrodes and a beam landing pad plane, said positive and negative address electrodes being connected to respective Q and {overscore (Q)} outputs of said memory pixels through via2 paths extending through said oxide layer;
- a rotating beam suspended in space above said metal-3 layer by means of two torsion hinges extending from opposite sides of said rotating beam attached to the top end of beam posts, the lower end of said beam posts being attached at opposite corners of said metal-3 landing plane, said suspension space being determined by the height of said beam posts, said beam being addressed by means of said address electrodes to rotate in positive or negative direction until the beam tips contact said landing pads on said metal-3 layer, the minimum gap between said address electrode in the area around said via2 and a tilted beam in the area above said via2 being at least 20% of said suspension space.
1 more element
A projection display system, comprising:
- a light source for producing a beam of light along a first light path;
- optics inserted in said first light path, said optics providing one or more color light beams;
- one or more digital micromirror devices receiving said color light beams from said optics, modulating said light on a pixel-by-pixel basis and reflecting light from ON pixels along a second light path, said digital micromirror further comprising:
- a substrate layer, said substrate layer comprised of a pixel memory array;
- an oxide isolation layer on said memory array;
- a metal-3 layer on said oxide layer, said metal-3 layer comprised of an array of positive and negative address electrodes and a beam landing pad plane, said positive and negative address electrodes being connected to respective Q and {overscore (Q)} outputs of said memory pixels through via2 paths extending through said oxide layer;
- a rotating beam suspended in space above said metal-3 layer by means of two torsion hinges extending from opposite sides of said rotating beam attached to the top end of beam posts, the lower end of said beam posts being attached at opposite corners of said metal-3 landing plane, said suspension space being determined by the height of said beam posts, said beam being addressed by means of said address electrodes to rotate in positive or negative direction until the beam tips contact said landing pads on said metal-3 layer, the minimum gap between said address electrode in the area around said via2 and a tilted beam in the area above said via2 being at least 20% of said suspension space;
- control electronics for receiving image data and controlling said light source and the modulation of said digital micromirror device;
- projection optics placed in said second light path magnifying and projecting an image on to a viewing screen;
- and
- a light trap for receiving and discarding reflected light along a third light path coming from the OFF pixels on said digital micromirror devices.
8 more elements
Dependencies are inferred from the claim text.