DE20122617U1 - Projection system with array of rectangular micro-mirror elements for providing images at angles depending on mirror tilt angle in light ray steering system - Google Patents

Abstract

A micro-mirror (24) is connected to a substrate (10) via a post (21), a hinge (18c), a post (16c) and metal areas (12a) and an array of the micro-mirrors is disposed in a rectangular shape with a capability of rotation around a switching axis between on and off states corresponding to pixels in a viewed image. Light is directed from a source to the mirrors non-perpendicularly to at least two sides of each mirror, while reflected light is received from collection optics. Independent claims are included for an array of movable micro-mirrors, for a method of positioning an image on a target, for a method of spatially modulating light beams, for an optical micro-mirror element, for a packaged micro-electromechanical device and for a method of making a micro-mirror.

Description

BACKGROUND

The The present invention relates to movable micromirrors and micromirror arrays for e.g. Projection displays. U.S. Patents 5,835,256 and 6,046,840 to Huibers and U.S. Patent Application 09 / 617,419 to Huibers et al., the contents of which are incorporated herein by reference, disclose microelectromechanical Devices (MEMS) for controlling light rays, such as an optical switch, and / or a display device (e.g. a projection display). A general feature is a micromirror element, that is movable, so that it is light dependent from the inclination angle of the micromirror element in different Distracts angles. In a type of conventional direct viewing or Projection display system is for the generation of an image is an array of reflective micromirror elements intended. Typically, the micromirror elements are rectangular or square and either have a certain angle of inclination for the "ON" state, and are flat in the "off" state, or they have for the "on" and "off" states the same angles of inclination, but with opposite signs.

SUMMARY THE INVENTION

According to one According to the invention, a projection display is provided, comprising: a light source for supplying light to an array Micromirrors; an array of micromirrors, each micromirror has a shape formed by means of several micromirror sides is defined; taking light from the light source while operating on the array from micromirrors impinges; and wherein the array has four sides and no micromirror sides parallel to one of the sides of the array are.

According to one Another aspect of the invention is a back or front projection TV comprising: an array of micromirrors, wherein the Micromirror micromirror plates comprise, via joints with a substrate and wherein the substrate, the micromirror plates and the joints are arranged in different levels; a light source for delivering light to the array of micromirrors; a screen, on which the picture to be viewed is displayed; being light from the light source during of the operation is incident on the array of micromirrors and when the image to be viewed is directed onto the screen; the Micromirrors are able to adapt themselves by pulse width modulation between an off state and an on-state to move the image on the screen produce; and wherein the micromirror array is rectangular with four sides and in each micromirror of the array, there is no micromirror plate side is parallel to one of the four sides of the micromirror array, and being light coming from the light source onto the micromirror array incident a) substantially perpendicular to one side of the micromirror array is, b) substantially perpendicular to an axis of rotation of the micromirrors and c) to none of the micromirror plate sides of the micromirrors is vertical.

According to another aspect of the invention, there is provided a rear projection TV comprising: an arc lamp for providing light to a light modulator having a rectangular array of micromirrors; wherein the micromirrors of the array are tiled, and each micromirror has four substantially rectilinear sides, and wherein the micromirrors are substantially square; a screen on which an image to be viewed is displayed; during operation, a beam of light from the arc lamp impinges on the array of micromirrors and is directed onto the screen as a rectangular image; wherein the micromirrors of the array are capable of moving between an off-state and an on-state by pulse width modulation to produce an image on the screen; wherein both the on and off states of the micromirrors are at positions other than an undeflected state; wherein the on position of the micromirrors is 10 to 15 degrees with respect to a non-deflected position; wherein none of the four substantially straight sides of the micromirrors are parallel to one of the sides of the array; wherein the viewed image has four sides; wherein the micromirror array has a substantially rectangular shape; one or more lenses for directing and focusing a beam of light onto the micromirrors; wherein the light beam is incident at an angle of substantially 90 degrees to at least one side of the rectangular array; wherein the light beam incident on the micromirrors has 10 to 50 degrees with respect to a line perpendicular to the plane of the micromirrors when they are not deflected; the micromirrors comprising micromirror plates connected by joints to a substrate; the substrate, the micromirror plates and the joints being arranged in different planes; wherein the micromirrors are positioned on a grid which is inclined to the sides of the rectangular array; wherein the micromirrors are disposed on a semiconductor substrate that is a silicon substrate; wherein the micromirrors are connected via underlying joints to the silicon substrate by an electrically conductive material; wherein the micromirrors are formed on the silicon substrate with circuits and electrodes adjacent to the micromirrors; wherein at least two electrodes are adjacent to each micromirror, one of the two electrodes for the electrostatic drive of the adjacent th micromirror is provided in an off position, and another of the two electrodes for an electrostatic actuation of the adjacent micromirror in an on position; the light being directed at an angle substantially perpendicular to the switching axis of the micromirrors; wherein the micromirrors in the array have switching axes that are at an angle of 35 to 60 degrees to one or more sides of the micromirrors; the micromirrors having substantially no micromirror sides perpendicular to the incident light beam from the light source; wherein the micromirror comprises a reflective material comprising aluminum; wherein the micromirror array is disposed in a housing having a translucent window, the translucent window being made of glass or quartz; wherein the micromirror array comprises an array of circuits and electrodes on a semiconductor substrate, and a set of bonding wires for electrically connecting the semiconductor substrate to the housing; and wherein the projection TV further comprises multi-lens optics arranged to project the light reflected from the micromirrors onto the screen.

In addition, the invention has the following additional aspects:
In order to minimize the diffraction of light along the switching direction and in particular diffraction of light into the collecting cone of the collection optics, micromirrors are provided in the present invention which are not rectangular ("rectangular" as used herein also includes square micromirrors). As used herein, the term "diffraction" refers to the scattering of light on a periodic structure, where the light is not necessarily monochromatic or phase coherent. In addition, to minimize the cost of the illumination optics and the size of the display unit of the present invention, the light source is placed perpendicular to the rows (or columns) of the array, and / or the light source is placed perpendicular to a side of the frame that surrounds the light source limited active area of the array. However, although it is perpendicular to the rows (or columns) and / or the active area side, the incident light beam should not be perpendicular to the sides of the individual micromirrors in the array. Vertical sides cause incident light to be diffracted along the direction of micromirror switching and result in light loss in the "ON" state even when the micromirror is in the "OFF" state. This diffraction reduces the contrast ratio of the micromirror.

The present invention optimizes the contrast ratio of the micromirror array, so that micromirror, when they are in their "off" state, send a minimal amount of light into the room area, into the light is steered when micromirrors are in their "ON" state. In particular the present invention a special arrangement of light source and incident light beam, as well as specially designed micromirrors in the array, which diffracts the light into the entrance cone of the projection optics Minimize (or viewing optics), so that an improved contrast ratio is made possible. The structure and the embodiment of the present invention also minimize also non-reflective Areas in the array, by a close juxtaposition of the micromirrors allows and thus a high fill factor, with low diffraction from the "OFF" state to the "ON" state, itself when the array is illuminated along the axis of micromirror periodicity. This means, the embodiment optimizes the contrast ratio by inclined sides, which are not parallel to the axis of rotation of the micromirrors, and optimized the fill factor through joints that have a relatively small area requirement and adjacent it Enable micromirrors, tiled with little loss due to non-reflective surfaces to lie to each other. The micromirror structures and configurations The various examples of the invention also reduce crosstalk between adjacent micromirrors when micromirror deflected electrostatically become.

One Another aspect of the invention is a micromirror array. in which the individual micromirrors are asymmetrically around a flat or non-deflected state. Due to the fact that the "OFF" state of the micromirror corresponds to an angle smaller than the opposite one The angle of the micromirror in the "ON" state becomes a) minimizes the amount of light diffracted by the edges of the micromirrors and enters the collection optics, b) the amount of light is minimized, which is scattered from below the micromirror and into the collection optics c) the migration of micromirrors is reduced, whereby the possibility is minimized that adjacent Micro mirror collide, which in turn makes it possible to reduce the gap between the micromirrors and the fill factor of the micromirror array, and can d) the deflection angle of the micromirrors is increased to a greater extent than micromirror array arrangements with the same deflection angle for the ON and OFF states.

Another aspect of the invention is a package (or package) for the micromirror array that has a transmissive region that is not parallel to the substrate on which the micromirrors are formed. The translucent region may be made of any suitable material, such as a plate of glass, quartz, or polymer, and allows a mirror reflection from the translucent substrate to be directed in directions, which differ from those resulting from a parallel translucent plate in the housing. Preferably, the specular reflection is deflected sufficiently far away from the collection optics, so that an enlargement of the illumination cone prevents the specular reflection from entering the collection optics.

One Another aspect of the invention is a projection system comprising an array of active micromirrors that are in a rectangular shape are arranged, wherein the micromirrors are able to a Switching axis between an OFF state and an ON state rotate, the micromirrors being pixels of a viewed image correspond; a light source that emits light onto the array of micromirrors directed, wherein the light source is arranged so that they light not perpendicular to at least two sides of each micromirror, and, viewed in a plan view of the micromirrors, in parallel to at least two other sides of each micromirror; as well as one Collecting optics that is designed to light from the micromirrors in one ON state to receive.

One Another aspect of the invention consists in a projection system, comprising an array of micromirrors, each micromirror corresponds to a pixel in a viewed image and a shape a concave polygon or one or more non-rectangular ones Has parallelograms; a light source to light on the array from micromirrors; as well as a collection look that designed is to receive light that reflects off the micromirrors becomes.

One Another aspect of the invention consists in a projection system, which comprises a light source, to create an incident beam of light, an array of moving beams reflective elements, and a collection optics for projecting of light from the array, one projected by the projection system Picture appears on a target as a rectangular image, taking the picture Made up of thousands to millions of pixels, each one Pixel has the shape of a concave polygon, not a single one rectangular Parallelogram, or an array of non-rectangular parallelograms.

One Another aspect of the invention consists in a projection system, which comprises a light source, an array of movable micromirror elements and collection optics, wherein each micromirror element in the array has a switching axis, substantially parallel to at least one side of the active one Area of the array is and at an angle between 35 and 60 degrees lies to one or more sides of the micromirror element.

One Another aspect of the invention is a projection system comprising a light source and an array of movable micromirror elements, wherein each micromirror element has a front side which is not is perpendicular to the incident light beam and to no side of the active region is perpendicular, so that an enlargement of the contrast ratio by a factor of 2 to 10 compared to micromirror elements with Pages that are perpendicular to the incoming light beam.

Another aspect of the invention is a projection system comprising a light source, a collection optics, and an array of movable micromirror elements, the projection system having a diffraction pattern substantially similar to that found in FIG 21C is shown.

One Another aspect of the invention is a projection system comprising a light source and a rectangular array of movable micromirror elements, wherein the micromirrors are capable of being between an ON state and an OFF state, and are capable of being in the ON state Reflecting light in a predetermined area of space, where the light source is arranged to light at an angle from substantially 90 degrees to at least one side of the Array defined rectangles deflects, and wherein essentially no diffracted light enters the predetermined space area when the micromirrors are in the OFF state.

One Another aspect of the invention is a method for projecting an image on a target, comprising: directing a light beam on a rectangular array of micromirrors, where the light beam directed at an angle to the front of the rectangular array which is in a range of 90 degrees plus or minus 40 degrees, and wherein the micromirrors are formed in the array as polygons and are arranged so that the Light beam hits all polygon sides at an angle, which is not 90 degrees; and projecting the light from the micromirrors to a target, to create an image on it.

Another part of the invention consists in a projection system comprising a light source, a light collection optic and an array of micromirrors arranged to spatially modulate a light beam from the light source, the array being formed on a substrate and constructed so that each one Micro-mirror is able to be in a first position when it is not addressed, each micromirror is able to move to an ON position in the light in the light collection optics for the Array is steered, and in the The position is to move in an opposite direction to an OFF position to deflect light away from the light collection optics, wherein both the ON and OFF positions are different from the first position and wherein the ON position is at an angle with respect to the first position, which differs from the OFF position.

One Another aspect of the invention is a method for spatial Modulation of a light beam comprising: directing a light beam from a light source to a light collection optic via an array of micromirrors, which are arranged to spatially to the light beam from the light source modulate, wherein the array is formed on a substrate and each micromirror is in a first position when he is not modulated, as well as modulating the micromirrors in the Array, so every micromirror moves into an ON position, in the light to the light collection optics for the Array is steered, and moved to an OFF position to light from The light collection optics wegschulenken, with both the EIN- as also distinguish the OFF position from the first position and the ON position of a size one Angle corresponds to the first position, the different is the size of one Winkels in the OFF position.

One Another aspect of the present invention consists in one a substrate formed optical micromechanical element with an ON position at a first magnitude of an angle relative to Substrate, with an OFF position at a second size of a Angle to the substrate, where the first and second sizes are different, and with a third position substantially parallel to Substrate is defined with both the ON and the OFF position are by striking the optical micromechanical elements against the substrate or against structure formed on the substrate.

One Another aspect of the present invention is a method for Modulation of light comprising reflecting light from one Array of deflectable micromirrors mounted on a flat substrate are arranged; the micromirrors being in either a first position or a second position inclined; where the angle, the is formed between the first position and the subtrate and the Angle formed between the second position and the substrate is essentially different.

One Another part of the invention is a method for the modulation of Light comprising a light source, a planar light modulation array comprising deflectable elements and a collection optic, wherein the elements optionally in at least two states in the array, where the elements in the first state the light from the light source in direct a first angle into the collection optics, and where the elements in the second state, the light from the light source in a second Steer angles in the collection optics, with a third angle light represents which is reflected by the array as if it were a micromirror surface, where the difference between the first and the third and the second and the third angle is substantially different.

One Another aspect of the invention is a projection system comprising a light source for generating a light beam; comprising a micromirror array several micromirrors, which are provided in a path of the light beam are; as well as a collection optic, in a path of the light beam lies after the light beam is incident on the micromirror array and from the multiple micromirrors as a pattern of micromirrors in the "ON" state and in the "OFF" state is reflected in the array; wherein the micromirror array is a Substrate, the array of micromirrors is carried by the substrate, and every micromirror is able to turn into an ON position and to move an OFF position from a non-deflected position, wherein the ON position with respect the undeflected Position has a different angle than the OFF position.

One Another part of the invention is a method for projecting a Image on a target, comprising: directing a light beam from one Light source on a micromirror array; Modulate the micromirrors each in an ON or OFF position, wherein in the ON position Micromirror directing light to the collection optics, which is arranged to of light from the micromirrors in their ON position, wherein the pattern of the micromirrors generates an image in their ON and OFF states, and the position of the micromirrors in their ON position at a different Size of one Angle is compared to the size of the angle the micromirror in its OFF position.

One Another part of the invention is a method for spatial Modulation of a light beam comprising directing a light beam onto an array of micromirrors, where the micromirrors are able to move to a first or second position, wherein in the first position the micromirrors a portion of the incident on them Direct light beam into a collection optic, and wherein the minimum Distance between adjacent micromirrors, if they are in the second position is less than the minimum distance between the adjacent micromirrors, when these in the first position.

Another aspect of the invention is one Apparatus comprising a substrate on which a movable reflective or diffractive micromechanical device is formed; a housing which receives the substrate with the movable micromechanical device, wherein the housing has an optically transmissive window, which is not parallel to the substrate.

One Another part of the invention is a projection system comprising a light source, a light collection optic, a substrate on which a movable reflective or diffractive micromechanical device is formed; a housing, this is the substrate with the mobile micromechanical device receives; the case an optically transparent Window, which is not parallel to the substrate, wherein the packed micromechanical device in a path of a light beam of the light source is arranged to receive the light from the light beam and the collection optics collect the modulated light.

One Another part of the invention consists in a projector comprising a light source, a packaged (or encapsulated) MEMS device with a substrate having a micromechanical thereon Device and a window in the housing, with respect to the Substrate is arranged inclined, and a collection optics, which is designed to light from the light source after the modulation by the encapsulated Record MEMS device.

One Another aspect of the invention is a method for the production a micromirror comprising providing a substrate; secrete and patterning a first sacrificial layer on the substrate; secrete at least one joint layer on the sacrificial layer and structuring the at least one hinge layer to form at least one flexure hinge; Depositing and patterning a second sacrificial layer; secrete at least one mirror layer on the second sacrificial layer and Patterning the at least one mirror layer around a mirror element to build; and removing the first and second sacrificial layers, to expose the micromirror.

One Another aspect of the invention is an optical micromechanical Device comprising a substrate; a first column on the substrate; a bending joint, a front end of the flexure joint being on the column; a second pillar, which is attached to the rear end of the bending joint; and a at the second pillar attached plate.

BRIEF DESCRIPTION OF THE DRAWINGS

1 Fig. 12 is a plan view of one embodiment of the micromirrors of the present invention;

2A to 2E FIG. 15 are cross-sectional views of a method for producing the micromirrors of the present invention taken along line 2-2. FIG 1 ;

3A to 3D FIG. 15 are cross-sectional views of the same process incorporated into FIGS 2A to 2E is shown, but along the line 3-3 off 1 ;

4A to 4J Fig. 12 are cross-sectional views illustrating another method for producing micromirrors for the present invention;

5A to 5G Fig. 15 are cross-sectional views illustrating another method for producing micromirrors according to the present invention;

6A to 6C are plan views of various micromirror shapes and joint combinations;

7 FIG. 12 is a plan view of a portion of a micromirror micromirror array such as those of FIG 6A ;

8th Fig. 10 is a partial isometric exploded view of a micromirror of one embodiment of the invention;

9A to 9C FIG. 15 are cross-sectional views illustrating the response of a micromirror of the embodiment. FIG 8th demonstrate;

10A to 10D FIG. 3 is a cross-sectional view of a method according to another embodiment of the invention; FIG.

11A to 11C FIG. 15 are cross-sectional views showing the response of a micromirror constructed according to the method of FIG 10A to 10D has been prepared;

12 FIG. 12 is a top view of a plurality of micromirrors in a micromirror array constructed according to the method of FIGS 11A to 11C was produced;

13 is an isometric partial exploded view of the micromirror 12 ;

14A to 14C represent micromirrors with a flat undeflected "OFF"state;

15A to 15C represent micromirrors with deflected "on" and "off" states at equal angles;

16A to 16C represent micromirrors that have an angle for the "on" state that is greater than that for the "off"state;

17A to 17E illustrate a housing arrangement for micromirrors with a tilted window;

18 Fig. 12 is an illustration of the illumination system for the micromirror array of the present invention;

19A to 19E show the relationship between the angle of the incident light, the micromirror sides and the sides of the active area;

20 Fig. 12 is an illustration of a micromirror array of the prior art;

21 and 22 Figures 12-13 are illustrations of an embodiment of the invention in which square micromirrors are angled (or tilted) with respect to the sides of the active area;

23 to 25 represent micromirrors in which "front" edges and "back" edges of the micromirrors are not perpendicular to the incident light beam;

26A to 26F and 27A to 27F are representations of micromirrors which are in the form of one or more parallelograms;

28 is a representation of a single micromirror;

29 Figure 3 is an illustration of a micromirror array in which the front and back sides are partially perpendicular to the incident light beam and are partially at 45 degrees to the incident light beam;

30 and 31 Figures 12 and 11 are diagrams of a micromirror array in which the micromirrors do not have sides parallel or perpendicular to the incident light beam or the sides of the active region of the array;

32A to 32J are representations of micromirrors with corresponding joint structures; and

33A to 33C are representations of diffraction patterns with a diffraction line formed by the entrance cone of the collection optics ( 33A ) or with a diffraction line that passes by the entry cone ( 33B and 33C ).

DETAILED DESCRIPTION

Methods for microfabrication of a moveable micromirror or micromirror array are disclosed in US Pat. Nos. 5,835,256 and 6,046,840 to Huibers, the contents of which are incorporated herein by reference. A similar process for forming the micromirrors of the present invention is disclosed in U.S. Patent Nos. 5,143,731 and 4,605,842 1 to 3 shown. 1 FIG. 10 is a plan view of one embodiment of the micromirrors of the present invention. FIG. As in 1 can be seen, carry the pillars 21a and 21b a micromirror plate 24 by means of joints 120a and 120b above a lower substrate with electrodes (not shown) thereon, around deflections of the micromirror plate 24 to effect. As in

1 not shown, but will be explained in more detail below, can be thousands or even millions of micromirrors 24 may be provided in an array to reflect incident light thereon and to project an image to a viewer or to a target / screen.

The micromirror 24 and the other micromirrors in the array can be made by various methods. One method is in the 2A to 2E shown (along the cross section 2-2 in 1 ), in which the micromirrors are preferably formed on a transparent substrate, which is subsequently bonded to a circuit substrate. This method is further described in US Provisional Application 60 / 229,246 to Ilkov et al. with filing date 30 August 2000, and in US Patent Application 09 / 732,445 by Ilkov et al. with filing date 7 December 2000. Although the method is described in connection with a transmissive substrate, any other suitable substrate may be used, such as a semiconductor substrate with circuitry. If a semiconductor substrate such as a single crystal silicon is used, it may be preferable to electrically connect the columns of micromirrors to the metal layer 3 in the IC process and to use conductive materials for at least a portion of the micromirror. Methods for fabricating micromirrors directly on a circuit substrate (rather than on a separate translucent substrate) are discussed below.

As in 2A is a translucent substrate 13 (at least before adding further layers thereto) such as glass (eg Corning 1737F or Eagle 2000), Quartz, Pyrex ^™ , sapphire, and the like. The translucent substrate may opti have onale light-blocking layer added on its underside, which is helpful in handling the substrate during processing. Such a light-blocking layer could be a TiN layer which is deposited by reactive sputtering to a depth of 2000 angstroms on the backside of the transparent substrate which would later be removed after completion of the processing. The substrate may be of any shape and size, but the shape of a conventional wafer used in the manufacture of integrated circuits is preferred.

As in 2A also can be seen becomes a sacrificial layer 14 , such as amorphous silicon, deposited. The sacrificial layer may also be made of any other suitable material that may later be removed among the materials of the micromechanical structure (eg, SiO 2, polysilicon, polyimide, novolac, and the like). The thickness of the sacrificial layer may be in a wide range depending on the size of the movable element / micromirror and the desired tilt angle, although a thickness of about 500 Å to 50,000 Å, preferably about 5,000 Å, is preferred. As an alternative to amorphous silicon, the sacrificial layer may also be one of many polymers, a photoresist or other organic material (or even polysilicon, silicon nitride, silicon dioxide, and the like, depending on the materials to resist the etchant and depending on the etchant selected). , An optional adhesion promoter (eg SiO ₂ or SiN) may be provided prior to deposition of the sacrificial material.

There is a hole in the sacrificial layer 6 formed with width "d" to a contact area between the substrate 13 and to provide the later deposited layers of the micromechanical structure. The holes are formed by spinning a photoresist and directing light through a mask to increase or decrease the solubility of the photoresist (depending on whether the photoresist is a positive or a negative photoresist). The dimension "d" may be in a range of 0.2 to 2 microns (preferably 0.7 microns), depending on the finished size of the micromirror and the micromirror array. After development of the photoresist to remove the photoresist around the holes, the holes are etched into the amorphous sacrificial silicon with a chlorine or other suitable etchant (depending on the sacrificial material). The remaining photoresist is then removed, for example, with an oxygen plasma. The hole in the sacrificial layer may be of any suitable size, preferably having a diameter of 0.1 to 1.5 μm, and more preferably about 0.7 +/- 0.25 μm. The etching is performed down to the glass / quartz substrate or down to any intermediate layers such as primer layers. If the translucent substrate is etched at all, then preferably in an amount of less than 2000 Å. If the sacrificial layer 14 is a directly structurable material (such as a novolac or other photosensitive photoresist), then an additional photoresist layer is applied to the sacrificial layer 14 is deposited and developed, not needed. In such a case, the photoresist sacrificial layer is patterned to provide material in the areas of the hole (s) 6 and then optionally cured before additional layers are deposited.

At this point, as in 2 B you can see, a first sacrificial layer 7 For example, deposited by chemical vapor deposition. Preferably, the material is silicon nitride or silicon oxide deposited by LPCVD (Low Pressure Chemical Vapor Deposition) or PECVD (Plasma Enhanced Chemical Vapor Deposition), but any suitable thin film material such as polysilicon, a metal or metal alloy, silicon carbide, or an organic compound could also be used deposited at this point (of course, the sacrificial layer and the etchant should be adapted to the structural material (s) used). The thickness of the first layer may vary depending on the size of the movable element and the desired degree of stiffness of the element, which layer in one embodiment has a thickness of 100 to 3200 Å, more preferably between 900 and 1100 Å. As in 2 B can be seen, the layer stretches 7 in the holes etched in the sacrificial layer.

A second layer 8th is deposited as in 2C you can see. The material may be the same as the first layer (eg, silicon nitride) or otherwise (silicon oxide, silicon carbide, polysilicon and the like) and may be deposited by chemical vapor deposition as in the first layer. The thickness of the second layer may be greater or less than that of the first layer, depending on the desired stiffness of the movable element, the desired flexibility of the hinge, the material used, etc. In one embodiment, the second layer has a thickness of 50 Å to 2100 Å, but preferably about 900 Å. In another embodiment, the first layer is deposited by PECVD and the second layer by LPCVD.

In the in the 2A to 2E In the illustrated embodiment, both the first and second layers are deposited in the regions that make up the moveable (micromirror) element and pillars. Depending on the desired Stiffness of the micromirror element, it is also possible to deposit only either the first or the second layer in the region of the micromirror element. Also, a single layer instead of the two layers 7 . 8th be provided for all areas of the microstructure, although this could be at the expense of the rigidity of the plate and the flexibility of the joints. Also, if a single layer is used, the area forming the hinge may be partially etched to reduce the thickness in this area and increase the flexibility of the resulting hinge. It is also possible to use more than two layers to form a laminated movable element, which may be desirable in particular when the size of the movable element increases, such as for switching light beams in an optical switch. The materials used for such a layer or layers may also include metal alloys and dielectrics or compounds of metals and nitrogen, oxygen or carbon (especially the transition metals). Some of these alternative materials are described in US provisional patent application 60 / 228,007, the contents of which are incorporated herein by reference.

As in 2D is shown becomes a reflective layer 9 deposited. The reflective material may be gold, silver, titanium, aluminum or another metal, or an alloy of more than one metal, although preferably aluminum is deposited by PVD. The thickness of the metal layer may be between 50 and 2000 Å, but preferably about 500 Å. An optional metal passivation layer (not shown) may be added, eg a 10 to 1100 Å silicon oxide layer deposited by PECVD on the layer 9 is deposited. For the deposition of the metal layer 9 For example, other metal deposition techniques may be used, such as CFD (chemical vapor deposition) and electroplating. After depositing the layer 9 A photoresist is spin-coated and patterned, after which the metal layer is etched with a suitable metal etchant. In the case of an aluminum layer, chlorine (or bromine) chemistry may be used (eg, a plasma / RIE etch with Cl ₂ and / or BCl ₃ (or Cl ₂ , CCl ₄ , Br 2, CBr ₄ , and the like) with an optional preferred inert diluents, such as Ar and / or He). It should be noted that the reflective layer need not be deposited last, but instead directly on the sacrificial layer 14 could be deposited between other layers forming the micromirror element, or as the only layer forming the micromirror element. However, in some processes, because of the higher temperature at which many dielectrics are deposited, it may be desirable to deposit a metal layer after a dielectric layer.

Referring to 2E can be the first and the second layer 7 . 8th etched with known etchants or combinations of etchants (depending on the material used and the degree of isotropy desired) after the reflective layer. For example, the first and second layers may be provided with chlorine chemistry or fluorine (or other halide) chemistry (eg, a plasma / RIE etch with F ₂ , CF ₄ , CHF ₃ , C ₃ F ₈ , CH ₂ F ₂ , C ₂ F ₆ , SF ₆ and the like, or more likely with combinations of the above or with additional gases such as CF ₄ / H ₂ , SF ₆ / Cl ₂ or gases using more than one type of etching such as CF ₂ Cl ₂ , generally possibly with one or more inert diluents). Of course, if different materials are used for the first layer and the second layer, then another etchant may be used for the etch of each layer (plasma etch chemistry known in the art, depending on the materials used). If the reflective layer is deposited before the first and second layers, the etch chemistries used would be reversed. Also, depending on the materials used, all layers could be etched together. In the 2E shown recesses 20a and 20b with a width "e" are for the separation of the columns 21 from the micromirror body 22 intended.

The 3A to 3D represent the same procedure along another cross section (cross section 3-3 in FIG 1 ) and show the translucent substrate 13 on which a sacrificial layer 14 is deposited. On the sacrificial layer 14 becomes the structural layer 7 deposited. As in the 3B and 3C is seen before adding the layers 8th and 9 a part of the layer 7 away. The part that is removed is in the area where the joint is to be formed and allows for increased flexibility in the joint area. Such a "thinning" of the hinge region is disclosed in US Provisional Patent Application 60 / 178,902 to True et al. with filing date January 28, 2000 and in U.S. Patent Application 09 / 767,632 to True et al. with filing date of 22 January 2001, the contents of which are incorporated by reference. After removing parts of the layer 7 become the layers 8th and 9 added, after which the layers 7 . 8th and 9 structured as described above. As in 3D Obviously, have the joints 23 a width "a" which is in the range of 0.1 to 10 μm, preferably about 0.7 μm. The joints 23 are separated from each other by a recess "b" and separated from adjacent micromirror plates by recess "c", which may also be 0.1 to 10 μm wide, but preferably about 0.7 μm.

The process steps generally mentioned above can be carried out in various ways. For example, a glass wafer (eg, a Corning 1737F, an Eagle 2000, a quartz or sapphire wafer) may be provided and may be provided on the back side of the wafer with an opaque coating such as Cr, Ti, Al, TaN, polysilicon or TiN or other opaque coatings to a thickness of 2000 angstroms (or thicker depending on the material) to make the transparent substrate temporarily opaque for handling. Then according to the 1 - 4 after deposition of an optional adhesion layer (eg, a dangling silicone bonding material such as SiNx or SiOx, or a conductive material such as glassy carbon or indium-tin oxide), a hydrogenated amorphous silicon sacrificial material on the transparent one 5000 Angstrom thickness plasma deposited in a plasma enhanced chemical vapor deposition system such as Applied Materials P5000 (gas = SiH4 (200 sccm), 1500 sccm Ar, power = 100 W, pressure = 3.5 T, temperature = 380 ° C, Electrode distance = 350 mm or gas = 150 sccm SiHy, 100 sccm Ar, power = 55 W, pressure = 3 Torr, temperature = 380 ° C, electrode gap = 350 mm, or gas = 200 sccm SiH4, 1500 sccm Ar, power = 100 W, temperature = 300 ° C, pressure = 3.5 T, or other process items between these settings). Also, the sacrificial material could be deposited by LPCVD at 560 ° C as disclosed in U.S. Patent 5,835,256 to Huibers et al. the content of which is hereby incorporated by reference. Also, the sacrificial material could be deposited by sputtering, or the sacrificial material could be a material that does not contain silicon, such as an organic material (which is later removed, for example, by plasma oxygen ashing). The a-Si is patterned (applying a photoresist and etching with a chlorine chemistry, eg, Cl2, BCl3, and N2) to form holes for attaching the micromirror to the glass substrate. A first layer of silicon nitride for producing the rigidity of the micromirror and for connecting the micromirror to the glass is deposited by means of PECVD in a thickness of 900 Angstroms (RF power = 150 W, pressure = 3 Torr, temperature = 360 ° C, electrode distance = 570 mm, gas = N2 / SiH4 / NH3 (1500/25/10) or HF power = 127 W, pressure = 2.5 Torr, temperature = 380 ° C, gas = N2 / SiH4 / NH3 (1500/25/10 sccm), electrode spacing = 550 mm, other process parameters can be used, such as a power of 175 W and a pressure of 3.5 Torr) and structured (pressure = 800 mT, RF power = 100 to 200 W, electrode distance = 0.8 to 1.1 mm, gas = CF4 / CHF3 / Ar (60 or 70/40 to 70/600 to 800 sccm, He = 0 to 200 sccm)) to remove the silicon nitride in the areas where the micromirror joints are formed. Next, a second layer of silicon nitride is deposited by PECVD in a thickness of 900 Angstroms (RF power = 127 W, pressure = 2.5 T, temperature = 380 ° C, gas = N2 / SiH4 / NH3 (1500/25/10 sccm ), Electrode gap = 550 mm). Then, Al is sputtered on the second silicon nitride layer in a thickness of 500 angstroms at a temperature of 140 to 180 ° C, a power of 2000 W, and Ar = 135 sccm. Also, instead of Al, the material could also be an aluminum alloy (Al-Si (1%), Al-Cu (0.5%) or AlSiCu or AlTi), or even an implanted or a target-doped aluminum. The aluminum is structured in the P5000 with a chlorine chemistry (pressure = 40 mT, power = 550 W, gas = BCl3 / Cl2 / N2 = 50/15/30 sccm). Then the SiN layers are etched (pressure = 100 mT, power = 460 W, gas = CF4 / N2 (9/20 sccm)), followed by ashing in H2O + O2 + N2 chemistry in plasma. Next, the remaining structures are ACT cleaned (acetone + DI wafer solution) and spin dried. (This cleaning can also be done with the EKS265 Resist Remover from EKC Technology or other solvent-based cleaners). After the photoresist coating of the front side of the wafer with the microstructures thereon, the backside TiN is etched in a BCl3 / Cl2 / CF4 chemistry in plasma (or other CRC Handbook of Metal etchants) or polished or abraded by CMP , or in an acidic vapor such as HF, followed by a second ACT cleaning (acetone + DI wafer solution) and a second spin drying. The wafer is split into individual dice and each die is exposed to a 300W CF4 plasma (pressure = 150 torr, 85 sccm for 60 seconds) followed by a 300 scc etch in a mixture of He, XeF2 and N2 (etching pressure 158 Torr). The etching is performed by placing the die in a chamber of N 2 at about 400 torr. A second area / chamber contains 3.5 Torr XeF2 and 38.5 Torr He. A separator between the two regions / chambers is removed, resulting in a combined XeF2, He and N2 etching mixture.

Also, the transparent wafer (eg Corning 1737F) can be coated with TiN to a thickness of 2000 angstroms on the back of the glass wafer. Subsequently, according to the 1 - 4 , without an adhesion layer, deposited hydrogenated amorphous silicon sacrificial material on a 5300 angstrom glass wafer in an Applied Materials P5000 (power = 100 W, pressure = 3.5 T, temperature = 300 ° C, SiH4 = 200 sccm, Ar = 1500 sccm, or pressure = 2.5 Torr, power = 500 W, temperature = 360 ° C, electrode gap = 350 mm, SiH4 flux = 200 sccm, Ar flux = 2000 sccm). The a-Si is patterned (photoresist and etching using a chlorine chemistry, eg C12, BC13 and N2 - 50 W) to form holes for mounting the micromirror on the glass substrate. A first layer of silicon nitride to provide rigidity of the micromirror and connect the micromirror to the glass is measured by PECVD (pressure = 3 torr, 125 W, 360 ° C, distance = 570, SiH4 = 25 sccm, NH3 = 10 sccm, N2 = 1500 sccm)) in a thickness of 900 angstroms and patterned (CF4 / CHF3) to remove the silicon nitride in areas where the micromirror joints are formed. Next, a second layer of silicon nitride is deposited by means of PECVD (same conditions as in the first layer) to a thickness of 900 angstroms. Then Al is sputtered to the second silicon nitride layer at a thickness of 500 Angstroms (150 ° C). The aluminum is structured in the P5000 with a chlorine chemistry (BCl3, Cl2, Ar). Then the SiN layers are etched (CHF3, CF4), followed by ashing in a barrel asher (O2, CH3OH at 250 ° C). Next, the remaining structures are cleaned with EKC Technology's EKS265 photoresist remover. After the photoresist coating of the front side of the wafer with the microstructures thereon, the TiN on the back side is etched in an SF6 / Ar plasma, followed by a second cleaning and a second spin drying.

To depositing the sacrificial and structural layers on a wafer substrate The wafer is split and each die is then placed in a Drytech parallel-plate RF plasma reactor placed. 100 sccm CF4 and 30 sccm 02 flow into the plasma chamber, the at about 200 mTorr for 80 seconds is operated. Then the raw chip for 300 seconds at 143 Torr etching pressure etched (combines XeF2, He and N2). The etching is carried out by the raw chip at about 400 Torr is exposed in a chamber of N2. A second area / chamber includes 5.5 Torr XeF2 and 20 Torr He. A separator between the two areas / chambers is removed, resulting in a combined XeF2, He and N2 etching mixture leads. The above can also be used in a parallel plate plasma etcher a power of 300 W CF4 (150 torr, 85 sccm) for 120 seconds carried out become. additional Features of the second (chemical, plasma-free) etch are disclosed in U.S. Patent Application 09 / 427,841 by Patel et al. with filing date October 26, 1999 and in US Patent Application 09 / 649,569 by Patel et al. with filing date of 28 August 2000 disclosed by Reference is included here.

Although the joint of each micromirror, as indicated above, can be formed substantially in the same plane as the micromirror element (in FIG 3D layers 7 . 8th and 9 of the micromirror body to layers 8th and 9 the micromirror joint), these may also be formed separately from and parallel to the micromirror element in a different plane and as part of a separate processing step (after the deposition of a second sacrificial material). This overlapping joint type is in the 8th and 9 of the aforementioned U.S. Patent 6,046,840 and disclosed in more detail in U.S. Patent Application 09 / 631,536 to Huibers et al. with filing date of 3 August 2000, which is hereby incorporated by reference.

Regardless of whether as in the figures, a sacrificial layer has been formed, or two (or more) sacrificial layers, as in the superimposed joint, sacrificial layers are removed with a preferably isotropic etchant, as described hereinafter. This "exposure" of the micromirrors may be performed immediately after the steps described above, or just prior to placement on the circuits on the second substrate. If the circuits, electrodes and micromirrors are not formed on the same substrate, then after formation of the micromirrors on a transparent substrate as described above, a second substrate is provided comprising a large array of electrodes on an upper metal layer (eg metal 3 ) of the substrate (eg, a silicon wafer). As in 11A is seen, becomes a translucent substrate 40 with an array of micromirrors formed thereon 44 to a second substrate 60 bonded to circuits and electrodes at voltages V ₀ , V _A and V _B formed thereon as the last layer (for a micromirror design with a single direction of motion, a single electrode per micromirror may also be used, such as in FIG 1 is shown). The micromirrors 44 are from the electrodes on the substrate 60 by means of spacers 41 spaced apart (eg, photoresist spacers adjacent to each micromirror and / or spacers that are in the epoxy when the substrate 40 on the substrate 60 is bonded). One or more electrodes on the circuit substrate electrostatically control a pixel (a micromirror on the upper optically transmissive substrate) of the microdisplay. The voltage at each electrode on the surface of the backplane determines whether its corresponding microdisplay pixel is optically "ON" or "OFF", thereby forming a visible image on the microdisplay. Backplane details and methods for generating a pulse width modulated greyscale or color image are disclosed in US Patent Application 09 / 564,069 to Richards, which is incorporated herein by reference. The construction of the first and second substrates is described in more detail in the patent applications of Ilkov et al. referred to above. There are several types of wafer receipt in the art Such as adhesive bonding, anodic bonding, eutectic bonding, fusion bonding, microwave bonding, solder bonding and thermocompression bonding.

The Exposing the micromirrors of the present invention may include Single-step or multi-step process, the process type of depends on the type of sacrificial material used. In one embodiment the invention is the first etching with a relatively low selectivity (e.g., less than 200: 1, preferably less than 100: 1, and more preferably less than 10: 1), and a second etch with a higher one selectivity follows (e.g., greater than 100: 1, preferably greater than 200: 1 and more preferably greater than 1000: 1). Such a dual etch is disclosed in U.S. Patent Application 60 / 293,092 by Patel et al. with filing date of 22 May 2001, by Reference is included here. Naturally can Other methods may be used, depending on the sacrificial material. If the victim material is a photoresist or another organic Material can be exposed by oxygen plasma ashing or by means of a supercritical fluid. Plasmas containing pure oxygen can produce species that are organic materials attack to form H2O, CO and CO2 as products, and SiO2, Do not etch Al or Si. Also could, if the sacrificial material is SiO 2, an etchant such as an isotropic dry etchant (CHF3 + O2, NF3 or SF6). If the sacrificial material silicon nitride Fluorine atoms are used to isotropically etch the silicon nitride (e.g. CF4 / O2, CHF3 / O2, CH2F2 or CH3F plasmas). If the sacrificial matrix amorphous Silicon is, could Fluorine atoms in the form of XeF2, BrF3 or BrCl3 can be used. If the sacrificial layer consists of aluminum, a chlorine chemistry (BCL3, CCl4, SiCl4). Of course, every etchant (and sacrificial material) would be selected at least in part based on the required degree of undercut.

Another method for the formation of micromirrors is in the 4A to 4J shown. As in 4A can be seen, has a substrate 30 (This may be any suitable substrate, for example, a glass / quartz substrate or a semiconductor circuit substrate) a sacrificial material deposited thereon 31 , Any suitable sacrificial material may be used, preferably one having a high etch selectivity ratio between the material to be etched and the sacrificial material. One possible sacrificial material is an organic sacrificial material, such as a photoresist or other organic materials as set forth in U.S. Patent Application 60 / 298,529 to Reid et al. with filing date June 15, 2001. Depending on the exact structure of the structural layer (s), other known MEMS sacrificial materials such as amorphous silicon or PSG could be used. If the sacrificial material is not directly structurable, then a photoresist layer is formed 32 added and developed to form one or more openings ( 4B ). Then, as in 4C you can see openings 34 into the sacrificial material 31 etched and the photoresist 32 will be removed. As in 4D is seen, becomes a (preferably conductive) layer 35 finally, which will eventually form at least the flexible parts of the MEMS device (in this example, a micromirror structure). The layer 35 can also do the columns 36 for attaching the micromirror to the substrate, or even the entire micromirror body or parts thereof. As will be further described herein, the conductive layer comprises 35 in a preferred embodiment of this invention, a metal Si, Al, B nitride, wherein the metal is preferably a transition metal, in particular a late transition metal. The layer 35 may also have multiple layers, or a conductive layer of numerous other types of layers (structural dielectric layers, reflective layers, release layers, and the like). layer 35 is not required to be conductive, and depending on the particular processes used in the deposition process, the target material used, and the atmosphere used, the layer could 35 also be insulating.

4E shows the addition of the photoresist 37 (patterned), followed by etching of part of the nitride layer (s) 35 and removing the photoresist ( 4F ). Then, as in 4G you can see the micromirror structure material layer 38 deposited. The material can be conductive or insulating and can also consist of several layers. If the material is a single layer, it is preferably reflective (eg, an aluminum or gold layer, or a metal alloy layer). Then, as in 4H you can see a photoresist 39 added and developed, followed by ( 4I ) etching / removing portions of the layer 38 (such as in the area of parts that bend during operation). Finally, as in 4J can be seen, the sacrificial layer removed to expose the MEMS device, so that it is exposed on the substrate. Not in 4 they are shown on or in the substrate 30 formed circuits (if the substrate is a circuit substrate) or an opaque layer on the substrate 30 which improves the automated handling of the substrate (if the substrate is a translucent substrate such as glass, quartz, sapphire or the like).

As in the 4A to 4J can be seen, an exposed MEMS structure is created there, where the layer 35 forms a flexible portion of the MEMS device, whereas the layer 38 The structure forms due to the flexible nature of the layer 35 emotional. As you can see, the layer forms 38 Both the movable section, as well as the column or wall, the MEMS structure on the substrate 30 wearing. The movable element may act as a laminate of the layers 38 and 35 (or else, if desired, additional layers), or layer only 38 , or even just from layer 35 , The structure of the movable and flexible elements is dependent on the ultimate desired stiffness or flexibility, the desired conductivity, the MEMS device to be formed, and the like.

The according to the 1 to 4 The micro-mirrors formed are preferably formed on a transparent substrate and have a non-deflected "OFF" state and a deflected "ON" state. However, the micromirrors can also be formed from the same substrate as the micromirror control circuits and electrodes. Also, both the "on" and "off" states of the micromirrors may be in a position that differs from the position in a non-deflected state. In the in the 5 to 9 In the embodiment shown, the micromirrors are formed on the same substrate as the electrodes and circuits for moving the micromirrors. In addition, the micromirrors not only have deflected "ON" and "OFF" states, but the angle of deflection differs between "ON" and "OFF". As in the 5A to 5G 1, a semiconductor substrate with circuits (and / or circuits) formed thereon and electrodes may be the starting substrate for the production of the micromirrors according to the invention.

As in 5A can be seen, has a semiconductor substrate 10 with circuits for controlling the micromirror, a patterned metal layer deposited in discrete sections thereon 12a to 12e is formed - usually aluminum (eg the last metal layer in a semiconductor process). A sacrificial layer 14 is deposited on it as in 5B you can see. As in the previous embodiments, the sacrificial material may be selected from a variety of materials, depending on the adjacent structures and the desired etchant. In the present example, the sacrificial material is a novolac photoresist. As well as in 5B you can see openings 15a and 15b formed by conventional patterning method for a photoresist in the sacrificial material to openings 15a to 15b train with the metal areas 12a to 12c are connected. After forming the openings 15a to 15c be like in 5C you can see plugs or other connections 16a to 16c formed according to conventional plug forming method. For example, tungsten (W) may be deposited by CVD through a) silicon reduction: 2WF6 + 3Si -> 2W + 3SiF4 (This reaction is normally caused by reacting with the WF6 gas with exposed solid silicon areas on a wafer surface b) Hydrogen reduction: WF6 + 3H2 → W + 6HF (This process is carried out at reduced pressures, usually at temperatures below 450 ° C), or c) silane reduction: 2WF6 + 3SiH4 -> 2W + 3SiF4 + 6H2 (This reaction (LPCVD at about 300 ° C) is commonly used to create a W seed layer for the hydrogen reaction). Other conductive materials, particularly other refractory materials, may be used for the connectors 16a to 16c be used. After depositing a layer of the connector material, a chemical mechanical polishing (CMP) process is performed down to the sacrificial layer to secure the connectors as in FIG 5C shown to form. For some connector materials, it may be desirable to first deposit an interlayer to avoid stripping (eg, for a tungsten plug, a TiN, TiW, or TiWN interlayer may be deposited to surround the tungsten in the sacrificial material hole, and later to replace the sacrificial layer).

As in 5D As can be seen, a conductive layer is deposited and patterned to discrete metal areas 18a to 18c to produce, with corresponding underlying metal areas 12a to 12c via appropriate plugs 16a to 16c are electrically connected. The conductive layer may be made of any suitable material (aluminum, aluminum alloys, other metals alloys, conductive ceramic compounds and the like) deposited by suitable methods such as vapor deposition or electroplating. The material should preferably be both conductive and have a suitable combination of hardness, elasticity, etc. (as will be seen, the range 18c serve as a joint for the micromirror to be formed). Of course, the discrete areas have to 18a to 18c if different materials or properties are desired for the different regions, they are not formed simultaneously (this also applies to the other regions formed in the device, such as the regions 12a to 12e and the plugs 18a to 18c ). Of course, fewer processing steps are involved if all discrete areas within a layer are made of the same material that is deposited simultaneously. In the preferred embodiment, the conductive layer consists of either an aluminum alloy or a conductive binary or ternary compound (or higher order interconnects), such as each Nos., which are disclosed in U.S. Patent Application 60 / 228,007 to Reid, filed 23 August 2000, and U.S. Patent Application 60 / 300,533, to Reid, filed June 22, 2001, both of which are incorporated herein by reference, which are deposited by reactive sputtering. A suitable etch chemistry is used to pattern the conductive layer (eg, a chlorine chemistry for aluminum) to discrete conductive regions 18a to 18c train.

As in further 5E is shown, becomes a second sacrificial layer 20 deposited, which may consist of the same material as the sacrificial layer 14 , or of a different material (preferably the material is the same so that both layers can be removed simultaneously). Then the layer becomes 20 structured to an opening 20a down to the area 18c train. As with the formation of the openings in the sacrificial layer 14 , this can be effected by an additional layer of photoresist, or the layer 20 can be patterned directly if the material is a photoresist or other directly structurable material, as in 5F you can see a plug or a connection 22 formed by a preferably electrically conductive material on the sacrificial layer 20 is deposited, followed by a chemical-mechanical polish, which the plug 22 connected to the discrete area ("joint") 18c leaves. Then, as in 5G you can see the micromirror body 24 by depositing a (preferably conductive) layer, followed by structuring into the desired shape of the micromirror. A variety of micromirror shapes are possible, such as those disclosed in U.S. Pat 6A is shown, and as will be described in more detail below. However, the micromirror mold according to this example of the invention may have any shape, such as a square or diamond shape, as in FIGS 6B and 6C is shown. Of course, those shapes are preferred that allow for dense packing of the micromirrors, and thus a high fill factor (such as the micromirror shape 6A in an English-style array in 7 is shown). The dotted line in 6C (and later in 12 ) represents the axis of rotation of the micromirror.

Although various layers used in the manufacture of the micromirror according to the 5A to 5G As individual layers are illustrated, each layer (whether structural layer or sacrificial layer) may be formed as a laminate, eg, one layer of the laminate having improved mechanical properties and another layer having improved conductivity. Although in the preferred embodiment the structural materials are conductive, it is also possible to use the micromirror element 24 (or a layer within a laminate 24 ) conductive, as well as the control electrodes 12d and 18b (and layers / materials containing the electrodes 12d and 18b connect to the semiconductor substrate). In addition, the above-disclosed materials (metal, metal alloys, metal-ceramic alloys, and the like) need not necessarily include a metal, but may be, for example, silicon (eg, polycrystalline silicon) or silicon compound (eg, Si 3 N 4, SiC, SiO 2, and the like) , If Si3N4 is used as the structural material and amorphous silicon as the sacrificial material, xenon difluoride can be used as a gas phase etchant to remove the sacrificial amorphous silicon. If desired, the silicon or silicon compound (or other compound) used as the structural material may be cooled before and / or after removal of the sacrificial layer to improve the stress properties of the structural layer (s). 8th is an exploded view of the micromirror according to the 5A to 5G was formed.

One of the last steps in the fabrication of the micromirror is the removal of the sacrificial layers 14 and 20 , 9A is a representation of the micromirror after removal of the two sacrificial layers containing the micromirror 24 connected to the substrate 10 over the pillar 22 , the joint 18c , the pillar 16c and the metal areas 12c shows. The in 9A The micromirror shown is not moved or deflected because no voltage is applied to one of the underlying electrodes (discrete metal regions formed in the method described above), eg at the electrodes 18b or 12d , is created. This undeflected position is the "OFF" position of the micromirror, which in projection systems generally has an angle farthest from the "ON" position (to achieve the best possible contrast ratio for the projected image). The "ON" state of the micromirror, ie the position of the micromirror in which light is directed into the entry cone of the collection optics, is in FIG 9B shown. A voltage V _A is applied to the electrode 12d applied to the micromirror plate 24 electrostatically pull down until the edge of the plate 24 on the electrode 12e strikes. Both the micromirror plate 24 as well as the electrode 12e are at the same potential, in this example at a voltage V ₀ . As in 9C is shown when applying a voltage V _B to the electrode 18b the micromirror plate 24 deflected in an opposite direction, with their movement through the electrode 18a is stopped. The electrode 18a and the micromirror plate 24 are at the same potential (voltage V ₀ in this example). Depending on the size of the electrode 18b opposite the electrode 12d and the distance between these electrodes and the micromirror plate 24 , the must be on the electrodes 18b and 12d applied voltage should not be the same. These in 9C The deflected position shown is the "OFF" position in which light is deflected furthest away from the collection optics.

As by comparing the 9B and 9C As can be seen, the "OFF" position forms a smaller angle (with the substrate) than the "ON" position. In the following, when referring to the "on" and "off" angles (or those angles referring to the substrate or undeflected micromirror position), a sign of the angle is used (positive or negative with respect to the substrate or an undeflected position). This sign is arbitrary, but indicates that the micromirrors rotate in one direction to the "on" position and rotate in an opposite direction to an "off" position. The advantages of such an asymmetry are explained in more detail below. In one example of the invention, the "on" position is between 0 and +30 degrees and the "off" position is between 0 and -30 degrees, with the movement to the "on" position being greater than the movement in the "on" position "Exhibition. For example, the "on" position may be between +10 and +30 degrees (or between +12 and +20 degrees, or between +10 and +15 degrees), and the "off" position may be greater than 0 degrees and between 0 and -30 degrees (or within a smaller range between 0 and -10 degrees, or between -1 and -12 degrees, or between -1 and -10 or -11 degrees, or between -2 and -7 degrees) , In another example, the micromirrors are capable of rotating at least +12 degrees to the "on" position and between -4 and -10 degrees to the "off" position. Depending on the materials used for the joints, larger angles can also be achieved, such as an "ON" rotation between +10 and +35 degrees and an "OFF" rotation between -2 and -25 degrees (of course, material fatigue and a Creep at large angles to become a problem). Neglecting the direction of rotation, it is preferred that the "on" and "off" positions be at angles greater than 3 degrees but less than 30 degrees with respect to the substrate, and preferably the "on" position is greater than +10 Degrees and mirrors continue to rotate 1 degree (or more) in the "ON" direction rather than in the opposite "OFF" direction.

The 10A to 10D show another method and another micromirror structure. The variability in materials, layers, sacrificial etching, deposition of structural layers and the like is as above in the context of the previously described methods. For that in the 10A to 10D The method illustrated may be the substrate 40 either a translucent substrate (which may later be connected to a second substrate with circuitry and electrodes) or a semiconductor substrate having circuitry and electrodes already thereon. In the present example, the circuits and the electrodes are formed on a separate substrate, as in FIGS 11A to 11B you can see.

In 10A becomes a sacrificial layer 42 deposited and structured to an opening 43 train. Then, as in 10B shown a plug 46 formed (preferably as in the method of 5A to 5G Depositing a metal, metal alloy or other conductive layer and then leveling (eg by CMP) to form the plug). Then, as in 10C you can see a joint 50 is formed by depositing an electrically conductive material (having suitable amorphousness, elasticity, strength, strength, and the like). In the present example, the hinge (and / or micromirror) is an early transition metal silicon nitride such as Ta-Si-N, a late transition metal silicon nitride such as Co-Si-N or a metal or a metal-ceramic alloy such as For example, a titanium-aluminum alloy, or a titanium-aluminum oxide alloy. After depositing such a material, a photoresist is deposited and patterned to allow etching / removal of all areas except for the hinge areas 50 , Then, as in 10D shown the micromirror plate 44 formed by first the joints are protected by a photoresist and then a joint structure layer is deposited and patterned to the micromirror plate 44 form, which partially overlaps and therefore with the joint 50 connected is. As in the other embodiments, an array of thousands or millions of such micromirrors is formed in an array simultaneously.

Then, whether at the wafer or die stage, the substrate is mounted with micromirrors on a substrate with control circuitry and electrodes. In the present example, at least two electrodes per micromirror should be provided, one for each deflection direction, and preferably a third, to allow the micromirror to stop its movement (in one of the directions) by striking a material on top the same potential as the micromirror itself. The second substrate 60 with the electrodes 72 and 74 for the deflection of the micromirror and with a support pad or a support electrode 70 is in 11A shown. The micromirror is in 11A in an undeflected position. When a voltage V _A to the electrode 72 is applied, then the micromirror 44 deflected until he hits the electrode 70 suggests ( 11B ). This is the "on" position of the micromirror, which allows the light into the collection optics to enter the system. It is possible to design the gap between the substrates so that the ends of the micromirror plate 44 at the same time on the electrode 70 and the substrate 40 attacks. When a voltage V _B to the electrode 74 is applied, then the micromirror plate 44 deflected in the opposite direction until the end of the micromirror plate on the substrate 40 strikes. This is the "OFF" position of the micromirror ( 11C ). Due to the position of the joint 50 and the pillar 46 the angle in the "OFF" position is smaller than the angle of the micromirror in the "ON" position. An array of such micromirrors is in 12 represented and an exploded view of a micromirror, which according to the method of 10A to 10D was produced is in 13 shown.

14A Figure 12 is a cross-sectional view of multiple micromirrors in an array in which the micromirrors are not deflected in their "off" position (Group 100 ), whereas micromirrors are in their "ON" state (Group 102 ) are deflected out of the flat position so that they reflect light so that it can be seen (directly, on a target in a connected device, across a space on a screen, etc.) Such is a micromirror array arrangement more precisely in the 14B and 14C shown. As in 14B can be seen, is in the micromirrors in their "ON" state an incident beam of light 50 reflected by all micromirrors (in this figure all micromirrors are in their "ON" state) and the light is perceived as a cone of light 52 in an exit opening 60 is projected, and in most cases is passed into an imaging system (eg, a projection lens or projection lenses). The cone 54 represents the mirror reflection from the transparent cover. 14C is a representation of the micromirrors in their "OFF" state, with the cone 52 Represents light reflected from the micromirrors in this "off" state. The incident and reflected cone of light tapers onto the entire array, although in these figures, for simplicity, the cones of light are shown as being converged on a single micromirror.

The arrangement of 14B and 14C has the advantage that when the micromirrors are in their "OFF" state (not deflected), little light is able to pass through the gaps between the micromirrors and cause undesirable "gap scattering". However, as in 14C it can be seen that due to the repeating pattern of the micromirrors, diffracted light is produced (light 61a and 61b that is above the cone of reflected "off" light 52 extends). This unwanted light is generated by scattering or diffraction at the edges of the micromirrors ("edge scattering"). In particular, since the incident beam of light (and thus the outgoing beam of light) is made as large as possible to increase the efficiency, diffraction light such as the light can be made 61a that extends beyond the cone of reflected "OFF" light into the exit port 60 (eg the collection optics) and cause an undesirable reduction of the contrast ratio.

To avoid this "overlap" of "OFF" state light (including the diffraction light) and "ON" state light, the "OFF" state light and the "ON" state light may be further separated by deflecting the micromirrors in both the "on" and "off" states. As in 15A As can be seen, if the micromirror is deflected to its "off" state as shown in the figure, a portion of the light is properly reflected off the micromirrors away from the "on" state direction (eg, collection optics) be like the beam 116 is shown. Other light 112 will not impinge on the micromirror but will be scattered on the surface of the lower substrate (eg on underlying circuits and electrodes) and will enter the collection optics even if the adjacent micromirror is in the "off" state. Also could, as by the beam 114 instead, such as beam, the incident light may strike a micromirror, which may nevertheless result in columnar scattering 116 to be properly steered to the "OFF" angle. This "ON" arrangement is in 15B same as in 14B , However, as in 15C shown the "OFF" state together with the diffraction generated by the micromirror periodicity 61a shifted farther away from the "ON" angle to effect an improved contrast ratio due to diffraction / edge scattering (despite the contrast ratio decreased due to gap scattering as described above).

An improved micromirror array would maximize the distance between the "off" cone of light and the "on" cone of light (minimizing edge leakage into the cone of entry) and still minimize the gaps between adjacent micromirrors (minimize gap dispersion). One solution that has been tried has been to provide a micromirror array with micromirrors which, as in US Pat 15A to 15C for the "ON" state and the "OFF" state, and to provide a light absorbing layer under the micromirrors to reduce the gap spread. Unfortunately, this increases processing complexity or light is absorbed on the micromirror array assembly (on the light valve), which increases the temperature of the light valve and creates problems due to thermal expansion, increased fatigue, and increased droop of the Mi. crosstalk structures, enhanced failure of the passivation films, self-assembling monolayers and / or solvents, and the like.

As in the 16A and 16C As can be seen, micromirrors are provided which are deflected both in their "ON" state and in the "OFF" state, but with different deflection angles. As in 16A can be seen, are the micromirrors 100 deflected into an "OFF" state, which is at a deflection angle which is smaller than the deflection angle of the micromirrors 102 in its "on" state (deflected in an opposite direction from the flat or undeflected state). As in 16B can be seen, the "ON" state is unchanged (incident light 50 is called outgoing light 52 in the outlet opening 60 projected), with a certain mirror reflection 54 , In 16C in their "OFF" state, the micromirrors are in a sufficiently deflected position so that edge diffraction light 61a that is in the outlet 60 occurs, is eliminated, and yet only deflected so far that the edge diffraction light is kept out of the entrance cone to eliminate the slit scattering light from below the micromirrors due to a large deflection angle in the "OFF" state.

An additional feature of the invention lies in the encapsulation or grouping of the device. As mentioned above, the reflection of light through the translucent substrate can lead to specular reflection. As in 17A is visible, becomes an incident light cone 50 reflected by the micromirrors in their "on" state, reflecting as a reflected cone 52 is shown. Mirrored light coming from a surface of the translucent substrate 32 is reflected as a light cone 54 shown. It is desirable in the production of a projection system to increase the angle swept by the cone to increase light transmission and system efficiency. However, as in 17A you can see an enlargement of the cone 50 swept angle an enlargement of the cones 52 and 54 swept angle so mirror reflection light from the cone 54 in the outlet opening 60 will occur even when the micromirrors are in their "OFF" state (reducing the contrast ratio).

In order to allow an increase in the angle swept by the cones, and at the same time to avoid that mirror reflection enters the outlet opening, as in 17B you can see the translucent substrate 32 with respect to the substrate 30 arranged inclined. In many cases, the substrate is 30 the substrate on which the micromirrors (or other optical MEMS elements) are formed, whereas the substrate 32 is a translucent window in a housing for the optical MEMS device. The tilt angle of the window is greater than -1 degrees (the minus sign refers to the directions of the micromirror slopes). In one example, the window is inclined at an angle of -2 to -15 degrees, or between -3 and -10 degrees. In any event, the window is inclined with respect to the micromirror substrate at an angle which is preferably in the same "direction" as the "OFF" position of the micromirrors (with respect to the micromirror substrate and / or the housing bottom). As in 17B As can be seen, when the micromirrors are in the "on" state, there is a gap between the light reflected from the "on" micromirrors (light reflection cone 52 ) and the mirror reflection light (light cone 54 ). This "gap" is caused by the mirror reflection cone 54 due to the inclined translucent substrate is reflected to a greater distance. This arrangement allows, as in 17C it can be seen that the angle swept by the incident light cone (and the corresponding reflection light cones) from the "ON" micromirrors (cones 52 ) and from the translucent substrate (cone 54 ) to enlarge. (To simplify the illustration, the point of reflection of the light cone lies midway between the micromirror and the translucent substrate, although in reality the cone of light 52 is reflected by the micromirror (s) and the mirror reflection light cone 54 is reflected from the substrate.) The inclined translucent window allows, as in the 17B and 17C shown, a higher system efficiency and a larger light value etendue (Etendue = solid angle × area). A light valve, as in the 17B and 17C is able to modulate a light beam of larger etendue and can pass more light from a light source and is thus more efficient.

An encapsulated device is in the 17D and 17E shown. As in 17D can be seen, meets incident light 40 (this view is reversed with respect to the previous views) on the array and is reflected by it. As in 17E can be seen, allows a tilted translucent substrate 32 (with mask areas 34a and 34b ) not only, as described above, an increase in the angle swept by the light cone, but also also a gap between the mask of the window 32 and minimizes the micromirror array, thereby reducing light scattering and temperature rise in the package. The angle of inclination of the translucent window is between 1 and 15 degrees with respect to the substrate, preferably between 2 and 15 degrees, and more preferably between 3 and 10 degrees. As in the 17D to 17E You can see bonding wires 37 (electrically connecting the substrate to the housing to enable driving of the micromirrors or other micromechanical elements) are disposed at one end of the substrate in the housing where the inclined window is spaced greater than at the opposite end of the substrate. Thus, the sloped window allows the attachment of bonding wires and also allows a minimized distance between the translucent window and the micromirror substrate at one end of the substrate where there are no bonding wires. It should be noted that the light from one side of the housing is incident on the micromirror array corresponding to the position of the bonding wires and the raised side of the tilted window. Additional components may be present in the housing, such as case adhesives, molecular scavengers or other getters, or a source of detackifying agent (such as chlorosilanes, perfluorinated n-alkanoic acids, hexamethyldisilazane, and the like).

If the micromirrors of the present invention are for a projection display, there should be a suitable light source that illuminates the array and projects the image onto a target via the collection optics. In the 18 and 19a to 19c Figure 4 shows the arrangement of the light source and the light beam of the present invention incident on the array and on each micromirror, which enables an improved contrast ratio while minimizing the footprint of the projection system. As in 18 can be seen, directs a light source 114 a ray of light 116 at a 90 ° angle to the front 93 of the active region of the device (the active region of the device is a rectangle in the figure 94 ) Shown. The active area 94 would typically have from 64,000 to about 2,000,000 pixels in a generally rectangular array, as shown in FIG 18 is shown. The active area 94 reflects light (via micromirrors in the "ON" state) through a collection optics 115 on a target to produce a corresponding rectangular image on the target (eg a wall or a screen). Of course, the array could be shaped differently than rectangular and would effect a corresponding shape on the target (unless a mask is traversed). Light from the light source 114 is reflected by certain micromirrors (those in the "ON" state) in the array and passes through the optics 115 (represented by two lenses for simplicity). Micromirrors in their "off" state (in a non-deflected "quiet" state) direct light to an area 99 in 18 , 18 FIG. 10 is a simplification of a projection system that may include other components such as TIR prisms, additional focusing or magnifying lenses, a color wheel for forming a color image, a light guide, and the like, as known in the art. Of course, if the projection system is intended for maskless lithography or non-color applications that do not project a color image (eg, front or rear projection television, a computer screen, and the like), then a color wheel and other collection optics may be used. The target can not only be a screen or photoresist, but also the retina of a viewer, such as a direct-view display. As in 18 As can be seen, all "on" micro mirrors in the array together direct light onto a single collection optics, which may be a lens or group of lenses for directing / focusing / projecting the light onto a target.

Regardless of whether the viewed image is on a computer screen, television screen or on a film screen, the pixels on the screen (each pixel on the viewed or projected image corresponds to a micromirror element in the array) have sides that are not parallel to at least two of the There are four pages that define the rectangular screen image. As in an example of a micromirror element in FIGS 19A -E, the incident light beam does not strike any of the sides of the micromirror element perpendicularly. 19A is a perspective view of light incident on a single micromirror element, whereas 19B is a plan view and 19C is a side view. The incident light beam may deviate 10 to 50 degrees (eg 20 degrees) from the normal (to the micromirror / array level). See angle 133 in 19C ,

Regardless of the angle between the incident light beam and the micromirror plane, no sides of the micromirror are perpendicular to the light beam incident thereon (see 19D ). In a preferred embodiment, the micromirror sides should be at an angle ( 131 ) of less than 80 degrees, but preferably 55 degrees or less in terms of projection ( 102 ) of the axis of the incident light beam to the micromirror plane, more preferably 45 degrees or less, and most preferably 40 degrees or less. In contrast, the angle should be 132 is at least 100 degrees, preferably 125 degrees or more, more preferably 135 degrees or more, and most preferably 140 degrees or more. The switching (ie rotational) axis of the micromirror is in 19D through the dotted line 103 shown. The switching axis could also be at other locations along the micromirror, such as at line 106 , depending on the type of joints used. As in 19D can be seen, is the switching axis (eg 103 or 106 ) perpendicular to the projection of the incident light beam 102 to the level of the micromirror. 19E is like 19D , a top view - however, is in 19E a micromirror arrangement together with a light beam incident on the 2-D array of micromirrors 102 shown. It should be noted that each micromirror in 19E the shape of the in the 19A -D shown micromirror. As in 19E As can be seen, the entire shape of the micromirror array is a rectangle. Each of the four sides of the arrangement, 117 to 120 , is defined by dragging a line between the farthest pixels in the last row and column of the active area ( 121 - 124 ) (for example, page is 119 defined by a line containing the corner pixels 123 and 122 cuts). Although in 19E it can be seen that each of the "front" (closest to the light source) and "back" (farthest from the light source) sides 119 . 117 of the active region due to the shape of the micromirrors in the active region are "jagged", it should be remembered that up to about 3,000,000 micromirrors or more may be present on an area of 1 cm ² to 1 in ² . Therefore, except at an extreme magnification, the active area will be substantially rectangular, with the sides 118 and 120 (or 117 and 119 ) of the active area parallel to the sides 107 and r of the micromirror in 19D are (the micromirror in 19D is one of the micromirror elements in the active region of 19E ); the pages 117 and 119 (or 118 and 120 ) of the active area parallel to the switching axis 103 (or 106 ) of each micromirror (see 19D ) are; and where the pages 117 and 119 (or 118 and 120 ) of the active area is not perpendicular to the front or rear sides 125a -D of the micromirror are (see 19D ). 19E could be thought of as the projected image comprising a large number of projected pixels (with each projected pixel corresponding to those in FIG 19D has shown shape). According to the above, the pages are 118 and 120 (or 117 and 119 ) of the projected image parallel to the sides 107 and 108 the projected pixels and the pages 117 and 119 (or 118 and 120 ) of the projected image are not perpendicular to the sides 125a -D the projected pixels.

20 Figure 4 is an illustration of a 2-D micromirror array (of course with significantly fewer pixels than in a typical active area). To simplify the illustration (in 20 as well as in the 21 - 26 and 29 - 32 Although less than 60 micromirrors / pixels are shown, although a common display would be between 64K pixels (320x200 pixels) and 1.920K pixels (1600x1200 pixels = UXGA), or more (eg 1920x1080 = HDTV; 2048x1536 = QXGA). Due to the very small pixel size in the present invention, the achievable resolution is essentially unlimited. As in 20 As can be seen, the sides of each pixel are parallel to corresponding sides of the active area. Thus, each micromirror side is either perpendicular or parallel to the sides of the active region. In contrast, as in 21 shown, the micromirror sides neither parallel nor perpendicular to the sides of the active area. As will be seen below, in other embodiments, some pages are neither parallel nor perpendicular to the sides of the active area, and some pages may be parallel to the sides of the active area (as long as they are also parallel to the direction of a line, which is thrown by the incident light beam on the level of the micromirror).

In the 22 shown micromirror arrangement achieves a high contrast ratio. In addition, the micromirror arrangements as they are used in the 23 - 29 are shown, the addressing scheme. In particular, the 23 - 29 the advantage that the pixels are not arranged on a grid which is angled (or inclined) with respect to the X- and Y-axis of the array. Since conventional video image sources provide pixel color data in an XY raster, the arrangement of the pixels in. Avoids 23 - 29 non-trivial video processing to produce an acceptable image on the display. Also avoids the arrangement of 23 - 29 a more complicated layout of the display backplane (compared to 13 and 14 that would require twice as many rows or column wires to the pixel control cells). The horizontal line 80 in 22 connects the top row of micromirror elements, and the vertical lines 81A -D are based on the respective micromirrors of the top row (these horizontal and vertical lines correspond to an addressing of rows and columns in the array). As in 22 can be seen, only every second micromirror is connected in this way. In order to address all micromirrors, twice as many rows and columns are required, which leads to an increased complexity in the addressing of the device. 22 also shows support columns 83 at the corners of the micromirrors, which are connected to joints (not shown) under each micromirror element (the "superimposed" joints discussed above) and to an optically transmissive substrate (not shown) above the micromirror elements.

In a more preferred embodiment of the invention, which in 23 is shown is an arrangement 92 intended. A ray of light 90 is directed to the arrangement that none of the micromirror sides are perpendicular to the incident light beam. In 23 lie the front sides of the micromirror (with respect to the incident light beam 90 ) at an angle of approximately 135 degrees with respect to the incident light beam 90 , Preferably, the angle is greater than 100 degrees, preferably each but larger than 130 degrees. The contrast ratio is further improved when the angle between the incident light beam and the front side is at least 135 degrees, and may even be 140 degrees or more. As in 23 As can be seen, the orientation of the micromirror elements does not result in any addressing problems, as described above with reference to FIG 22 were discussed. The columns 95 are with the joints (not shown) under each micromirror element in 23 connected. The joints extend perpendicular to the direction of the incident light beam (and parallel to the front and back sides 91B and 91D of the active area). The joints allow a rotational axis of the micromirrors, which is perpendicular to the incident light beam.

24 is a representation of micromirrors similar to those in 23 is shown. However, in 24 the micromirror elements are "reversed" and have "concave" sections as fronts. Although the micromirror in 24 opposite the in 23 shown in reverse, continue to exist no micromirror sides, which are perpendicular to the incident light beam. 24 represents a joint 101 which is arranged in the same plane as the micromirror element to which the joint is attached. Both types of joints are disclosed in the aforementioned '840 patent. 25 equally poses a joint 110 in the same plane as the micromirror array, and shows both "convex" sections 112 ("Protrusions") and "concave" sections 113 ("Recesses") on the front of each micromirror. Due to the concave or recessed portions of each micromirror, each micromirror has the shape of a concave polygon. Although the micromirrors may be convex polygons (if neither side of the convex polygonal micromirror is parallel to the front of the active area), it is preferred that the micromirrors have a concave polygon shape. Convex polygons are known as polygons, where none of the lines that contain a page passes through the inside of the polygon. A polygon is concave if and only if it is not a convex polygon. The concave polygon shape may be formed from a series of (non-perpendicular) parallelograms, or at least one concave and at least one mating convex portion (for fitting into the concave portion of the adjacent micromirror), although any other concave polygon shape is possible , The micromirror shape may also be that of a single (non-perpendicular) parallelogram, although this is less preferred, as mentioned above. Although not shown, the mating one or more protrusions and the one or more recesses need not be constructed of straight lines (not the micromirror sides for this purpose), but may instead be curved. In such an embodiment, the protrusion (s) and the recess (s) are semicircular, although the illustrated angled protrusions and recesses are preferred.

The 26A to 26F Although the shapes of the micromirrors are different in the various figures, they are similar in that none of them has a side perpendicular to the incident light beam. Of course, when a micromirror page changes direction, there is a small point at which the page can be considered perpendicular, if only momentarily. If it is determined herein that none of the sides is vertical, it should be understood that there are no substantial portions which are perpendicular, or that at least no such substantial portions are present on the front and back of the micromirror. Even if the direction of the front sides changes gradually (or a portion of the back side is perpendicular to the incident light beam, as in FIG 29 however, it is preferred that no more than half of the face be perpendicular to the incident light beam, more preferably no more than a quarter, and most preferably one-tenth or less. The smaller the portion of the front and back faces that is perpendicular to the incident light beam, the greater the improvement of the contrast ratio.

Many of the micromirror embodiments can be viewed as an arrangement of one or more parallelograms (eg, identical parallelograms). Like in the 27A As can be seen, a single parallelogram is effective in reducing light bowing because it has no sides perpendicular to the incident light beam (with the light beam running on the side from bottom to top and originating off the side plane). 27A shows a single parallelogram with a horizontal arrow marking the width "d" of the parallelogram. The switching axis of the micromirror in 27A (and in the 27B to 27F ) also runs in this horizontal direction. For example, the switching axis along the dotted line in 27A run. The 27B and 27C show micromirror forms with two and three parallelograms, each subsequent parallelogram having the same shape, size and appearance as the previous one. This arrangement forms a "sawtooth" front and back of the micromirror element. The 27D to 27F represent two to four parallelograms. However, in the 27D to 27F each successive parallelogram a micromirror image of the preceding, instead of being the same picture. This arrangement forms "zigzag" front and back sides of the micromirror element. It should be noted that the parallelograms need not all be the same width, and that a line connecting the tips of the sawtooth or zigzag sides need not be perpendicular to the incident light beam. The width of each parallelogram, if constructed so as to have the same width, is "d" = M / N, where M is the total micromirror width and N is the number of parallelograms. As the number of parallelograms increases, the width "d" decreases (assuming a constant micromirror width). However, the width "d" should preferably be much larger than the wavelength of the incident light. In order to keep the contrast ratio high, the number N of parallelograms (or the frequency of changes in the front of the micromirror) should be less than or equal to 0.5 M / λ, or preferably less than or equal to 0.2 M / λ, or even less than or equal to 0.1 M / λ, where λ is the wavelength of the incident light. Although in 27 however, if the number of parallelograms is between one and four, any number is possible, although 15 or less, and preferably 10 or less, results in a better contrast ratio. The number of parallelograms in 27 is the most preferred (4 or less).

As in 28 can be seen are joints (or bending elements) 191 . 193 in the same plane as the micromirror element 190 arranged. An incident light beam 195 from a light source outside the plane of the 28 meets the front sides of the micromirror 190 on, none of which is vertical. Preferably, no portion of the joints is perpendicular to the incident light beam, so that the light diffraction is reduced in the direction of the micro-mirror circuit.

It should also be noted that the "straight" micromirror sides, shown as being parallel to the sides of the active region (eg, the micromirror sides 194 . 196 out 28 ) may also have other shapes. Above 21 is an example where no micromirror sides are parallel to the incident light beam 85 lie. The 30 and 31 are further examples in which no micromirror sides are perpendicular or parallel to the incident light beam and yet have no increased complexity in addressing, as shown in FIG 22 the case is. Incident light may be substantially perpendicular to one of the four sides of the active area in 30 be directed (see arrows 1 - 4 ), without being incident perpendicular to one of the micromirror sides.

This unique feature is also found in the 31 presented arrangement. In addition, it is also possible that a portion of the front edge of each micromirror is perpendicular to the incident light beam and a portion is not vertical, as in 29 you can see.

The 32A to 32J represent possible joints for the micromirrors of the present invention 24 provides 32A Micro mirror with bending elements 96 which extend parallel to the incident light beam (viewed from above in this figure) and the micromirror 97 with the holding columns 98 connect, which carry the micromirror elements on the substrate. The incident light can be in the direction of the arrows 5 or 6 in 32A be directed to the arrangement (viewed from above). Of course, the incoming light would have its origin outside the plane (see 11A to 11E ). Such an incident light would be the same for the 32B to 32L , The 32C to 32E are other embodiments of this type of joint. The 32F to 32L are illustrations of other joint and micromirror embodiments in which, with the exception of 32J , which do not extend joints parallel to the incident light beam (or to the front of the active area), but which still cause the micromirrors to rotate about an axis of rotation perpendicular to the incident light beam.

If the micromirror sides lying parallel to the axis of rotation of the micromirror (and perpendicular to the incident light beam) are not minimized, then light diffracted from such micromirror sides will pass through the collection optics even when the micromirror is in the "off" state is, whereby the contrast ratio is reduced. As in 33A As can be seen, a diffraction pattern (caused by the illumination of an array of substantially square micromirrors, such as those shown in FIG 20 at an angle of 90 degrees to the front of the assembly) in the form of a "+" the entrance cone (the circle in the figure). The diffraction pattern can be recognized in this figure as a series of dark spots (with a corresponding lighter background) forming a vertical and a horizontal line crossing just below the entrance cone circle, shown as a circular solid black line crossing over the diffraction pattern lies. In the "ON" state of the micromirrors, the two diffraction lines in the entry cone circle would intersect, which is not shown here. Therefore, as in 33A 4, the vertical diffraction line enters the input cone of the collection optics even when the micromirror is in the "OFF" state, thereby affecting the contrast ratio. 33B is a diffraction pattern created by illuminating an array of square micromirrors at an angle of 45 degrees. As in 33B can be seen in comparison to 33A less diffraction light into the entry cone (the small solid black circle in 33B ). Although, as mentioned above, diffraction can be reduced by such illumination, other problems may arise.

In contrast, the diffraction pattern of the present invention (the micromirror has 28 in the "OFF" state), as in 33C see, no diffraction line that passes through the cone of entry of the collection optics or otherwise enters the space area, is directed into the light, when the micromirror is in the "ON" state. Thus, substantially no light is diffracted into the area where light is directed when the micromirror is in the "on" state. A micromirror arrangement which produces such a diffraction pattern in which illumination light is perpendicular to the sides of the active area of the array (and / or perpendicular to the columns or rows) is novel. Likewise, the micromirror embodiments, the joints provided for this purpose, the arrangement of the light source with respect to the micromirrors, the sides of the active region and / or the addressing of rows and columns are also new.

The The invention has been described with reference to specific embodiments. Nevertheless, those skilled in the art will recognize that in the light of those described herein embodiments many changes possible are. For example, could the forms of micromirrors of the present invention for micromirrors be used in an optical switch (as he, for example is disclosed in U.S. Patent Application 09 / 617,149 to Huibers et al. with filing date July 17, 2000 and provisional US Patent Application 60 / 231,041 to Huibers with filing date B. september 2000, both of which are incorporated by reference herein his) to reduce the diffraction in the switch. In addition, the Micromirrors of the present invention also according to structures and methods can be prepared as described in US Patent Application 09 / 767,632 from True et al. with filing date January 22, 2001, the US patent application 09 / 631,536 to Huibers et al. with filing date 3 August 2000, the U.S. Patent Application 60 / 293,092 by Patel et al. with filing date May 22, 2001, and the US patent application 06 / 637,479 to Huibers et al. with filing date 11 August 2000 are. Although in a projection display that the micromirrors of the present invention involves a conventional red / green / blue or red / green / blue / white color wheel can be used also other color wheels as disclosed, for example, in US Provisional Patent Applications 60 / 267,648 to Huibers with filing date February 9, 2001 and 60 / 266,780 by Richards et al. with filing date February 6, 2001, both by Reference are included here.

moreover For example, the present invention is also suitable for a method that is a removable one (and replaceable) substrate for Used for separation and mounting purposes, as described in US Provisional Patent Application 60 / 276,222 to Patel et al. with filing date of 15 March 2001. moreover can they Micromirror of the present invention in an arrangement by Pulse width modulation are controlled, as in US Patent Application 09 / 564,069 by Richards with filing date of 3 May 2000, which was Reference is included here. If further, interhalogens or Edelglasfluoride as an etchant can also be used to expose the micromirrors Methods are used as described in US patent applications 09 / 427,841 by Patel et al. with filing date 26 December 1999 and 09 / 649,569 by Patel et al. with the filing date of 28 August 2000, both of which are hereby incorporated by reference. Also, the Sacrificial materials and the methods of their removal are U.S. Patent Application 60 / 298,529 to Reid et al. with filing date 15 June 2001. In addition, other structural materials can be used, such as the MEMS materials used in U.S. Patent Application 60 / 228,007 with filing date August 23, 2000 and U.S. Patent Application 60 / 300,533, filed June 22, 2001 are set out. Each of the above patents and patent applications is included by reference here.

but throughout the application, structures or layers have been described as being localized "on" (or deposited on) or over, above, adjacent to, etc. other structures or layers. It should be noted that it is meant to refer both directly and indirectly to, over, above, adjacent to, etc., as it is known in the art that various interlayers or structures could be provided, the sealant layers, primer layers , electrically conductive layers, layers to reduce static friction, and the like include, but are not limited to. Likewise, structures such as the substrate or a layer may be laminate-like due to additional structures or layers. When the terms "at least one" or "one or more" (or similar) are used, it is intended to emphasize the potential multiplicity of the particular structure or layer, which expressions in no way implicate that in other cases, too where this is not so explicitly stated, multiple structures or multiple layers can be used. Likewise, the use of the term "direct or indirect" should not be taken as limiting that in other cases where the This term is not used, either directly or indirectly. Also, the terms "MEMS", "micromechanical" and "micro-electro-mechanical" are used interchangeably herein, and the structure may or may not include an electrical component.

Claims (121)

Projection display, comprising: a light source for supplying light to an array of micromirrors; an array micromirrors, each micromirror having a shape, which is defined by means of several micromirror sides; in which Light from the light source during the operation impinges on the array of micromirrors; and in which the array has four sides and no micromirror sides parallel to one of the sides of the array. Projection display according to claim 1, wherein no Micromirror sides are parallel to the incident light beam, when the array is viewed from above. Projection display according to one of the preceding claims, in the incident light beam is perpendicular to one side of the array incident. Projection display according to one of the preceding claims, at the axis of rotation of the micromirrors parallel to one side of the array. Projection display according to one of the preceding claims, at the micromirrors are square. Projection display according to one of the preceding claims, at the micromirrors are arranged on a grid, which is to the X and Y axes of the array is tilted. Projection display according to one of the preceding claims, at the micromirror have micromirror plates, which via joints are attached to a substrate, and wherein the substrate, the micromirror plates and the joints are arranged in different levels. A projection display according to claim 7, wherein a first Gap formed between the joint and the micromirror plate is, and a second gap between the micromirror plate and the Substrate is formed. Projection display according to one of claims 7 to 8, in which a first gap between the substrate and the joint is formed, and a second gap between the joint and the Micro mirror plate is formed. Projection display according to one of the preceding claims, at a gap between adjacent micromirrors between 0.1 μm and 10 microns. A projection display according to claim 10, wherein the Gap between adjacent micromirrors has approximately 0.7 microns. Projection display according to one of the preceding claims, at the array of micromirrors is arranged in a housing which is a translucent window having. A projection display according to claim 12, wherein a Mask as part of the housing is provided. A projection display according to claim 13, wherein the Mask on the housing window is formed and around an exterior of the micromirror array extends. Projection display according to one of claims 12 to 14, in which a molecular scavenger is provided in the housing. Projection display according to one of claims 12 to 15, in which in the housing a getter is provided. Projection display according to one of claims 12 to 16, in which in the housing a means for reducing static friction is provided. Projection display according to one of the preceding claims, which a front screen projection TV is. Projection display according to one of claims 1 to 17, a screen projection TV is. Projection display according to one of the preceding claims, which further comprises a color wheel. Projection display according to one of the preceding claims, at that of the incident on the micromirror array light beam 10 to 50 degrees to form a line perpendicular to the plane of the micromirror is. Projection display according to one of the preceding claims, at the micromirrors are arranged on a semiconductor substrate. A projection display according to claim 22, wherein the Semiconductor substrate is a silicon substrate. Projection display according to one of the preceding claims, at the micromirrors are arranged on a transparent substrate are. A projection display according to claim 24, wherein the translucent Substrate is glass. A projection display according to claim 24, wherein the translucent Quartz or sapphire is. Projection display according to one of the preceding claims, at the micromirrors are capable of at least +12 degrees in to rotate the on position. Projection display according to one of the preceding claims, at the one-position of the micromirror 10 to 15 degrees from a non-deflected position away. Projection display according to one of the preceding claims, at the light source is an arc lamp. Projection display according to one of the preceding claims, which Further, a collecting optics having a plurality of lenses, the are arranged so that they project the light pattern from the micromirror array onto a target. Projection display according to one of the preceding claims, which further comprising one or more micromirrors or lenses to to focus and focus a cone of light on the micromirror array. Projection display according to one of the preceding claims, at the micromirror on a substrate adjacent to circuits and electrodes are formed, adjacent to each micromirror at least two electrodes are arranged, wherein one electrode electrostatically pulling the adjacent micromirror into an off position, and another electrode the adjacent micromirror electrostatically pulls into an on position. Projection display according to one of the preceding claims, which also an additional one Having electrode; and wherein the additional electrodes on the same potential as the adjacent micromirror lie. Projection display according to one of the preceding claims, at the micromirror comprises metal and a dielectric material. A projection display according to claim 34, wherein the dielectric material is a nitride, carbide or oxide of silicon is. Projection display according to one of the preceding claims, at the housing a hermetic housing is. Projection display according to one of the preceding claims, at The joints of the micromirror perpendicular to the direction of the incident light beam extend. Projection display according to one of the preceding claims, at The joints of the micromirror parallel to the front and back sides of the micromirror array. Projection display according to one of the preceding claims, at the joint of the micromirror an axis of rotation of the micromirrors enable, which is perpendicular to the direction of the incident light beam. Projection display according to one of the preceding claims, at when the micromirror array is viewed from above, one Line that indicates the incidence of the light beam on the micromirror array defined, to none of the sides of the micromirror is parallel. Projection display according to one of the preceding claims, at the at least 1000 micromirror provided in the micromirror array are. Projection display according to one of the preceding claims, at where the quadrilateral array is rectangular and at the light of the light source in the form of a light beam at an angle of 90 degrees plus or minus 40 degrees to the front of the rectangular Arrays is addressed. Projection display according to one of claims 1 to 42, wherein the micromirror comprises a reflective material, chosen from gold or titanium becomes. Projection display according to one of claims 1 to 42, wherein the micromirror comprises a reflective material, comprising aluminum. Projection display according to one of claims 1 to 42, wherein the micromirror comprises a reflective material, includes the silver. Projection display according to one of the preceding claims, at the off-state of the micromirror is at an angle, which is less than the opposite Angle of the micromirror in on-state. A projection display according to any one of the preceding claims, wherein the light is incident on the micromirrors where the light beam is not one of the Se is perpendicular to the micromirror and is perpendicular to the front and back sides of the array. Projection display according to one of the preceding claims, at the beam of light perpendicular to the axis of rotation of the micromirrors is. Projection display according to one of the preceding claims, at each micromirror has a switching axis substantially parallel to at least one side of the array. Projection display according to one of the preceding claims, at each micromirror has a switching axis at an angle from 35 to 60 degrees to all sides of the micromirror. Projection display according to one of the preceding claims, at the beam of light is perpendicular to none of the sides of the micromirror incident. Projection display according to one of the preceding claims, at the micromirrors have a single point on the leading edge, on which the light comes in. Projection display according to one of the preceding claims, at 64,000 to 2,000,000 micromirrors are formed in the array. Projection display according to one of the preceding claims, which further comprises a TIR prism. Projection display according to one of claims 1 to 52 and 54, with 2,000,000 to 3,000,000 micromirrors in the array are provided. A projection display according to any one of the preceding claims, wherein the micromirror array has an area of from 1 cm ² to 1 in ² . Projection display according to one of claims 1 to 52 and 54 to 56, in which the micromirror has a resolution of Has 1,920,000 or more. Projection display according to one of claims 1 to 57, with HDTV format. Projection display according to one of claims 1 to 57, with QXGA format. Projection display according to one of claims 1 to 57, with UXGA format. return or front projection TV, comprising: an array of micromirrors, wherein the micromirrors comprise micromirror plates over joints are connected to a substrate, and wherein the substrate, the micromirror plates and the joints are arranged in different planes; a Light source for supplying light to the array of micromirrors; one Screen on which the image to be viewed is displayed; in which Light from the light source during of the operation is incident on the array of micromirrors and when the image to be viewed is directed onto the screen; in which The micromirrors are capable of varying through pulse width modulation to move between an off-state and an on-state to create the picture on the screen; and being the micromirror array is rectangular with four sides, and being in each micromirror of the array does not have a micromirror plate side parallel to any of the four Is the sides of the micromirror array, and where light coming from the Light source incident on the micromirror array a) substantially perpendicular to one side of the micromirror array, b) is substantially perpendicular to an axis of rotation of the micromirrors, and c) to none of Micromirror plate sides of the micromirror is vertical. The projection television of claim 61, further comprising Color wheel has. Projection TV according to one of claims 61 to 62, further comprising a light guide. Projection TV according to one of claims 61 to 63, in which the light source is an arc lamp. Projection TV according to one of claims 61 to 64, which is a rear projection TV is. Projection TV according to one of claims 61 to 64, which is a front projection TV. Projection TV according to one of claims 61 to 66, in which none of the micromirror sides are parallel to the incident Beam of light is when the array is viewed from above. Projection TV according to one of claims 61 to 67, in which the micromirrors are rectangular. Projection TV according to one of claims 61 to 68, in which the micromirrors are square. Projection TV according to one of claims 61 to 69, in which the micromirrors are positioned so that no Micromirrors on a grid to horizontal and vertical axes of the rectangular array are inclined. Projection TV according to one of claims 61 to 70, in which a first gap between the joint and the micromirror plate is formed, and a second gap between the micromirror plate and the substrate. Projection TV according to one of claims 61 to 71, where the joint and the micromirror plate are in the same plane lie, when viewed in a natural state of rest from above. Projection TV according to one of claims 61 to 72, in which the array of micromirrors arranged in a housing is that a translucent window having. A projection TV according to claim 73, wherein a mask as part of the housing is provided. The projection television of claim 74, wherein the mask on the housing window is formed and around an exterior of the micromirror array extends. Projection TV according to one of claims 73 to 75, in which a molecular scavenger is provided in the housing. Projection TV according to one of claims 73 to 75, in which in the case a getter is provided. Projection TV according to one of claims 73 to 77, in which a source of a means for reducing static friction in the case is provided. Projection TV according to one of claims 61 to 78, wherein the incident on the micromirror array light beam 10 to 50 degrees with respect has a line which is perpendicular to the plane of the micromirror. Projection TV according to one of claims 61 to 79, where the micromirrors are capable of at least +12 Rotate degrees to the on position. Projection TV according to one of claims 61 to 80, further comprising a color filter to provide a series of sequential Having colors on the micromirror array. Projection TV according to one of claims 61 to 81, in which the rectangular array has two longer sides and two shorter sides and wherein the light beam is at an angle of substantially 90 degrees to a shorter one Side of the rectangular array. Projection TV according to one of claims 61 to 82, further comprising optics having a plurality of lenses, which are arranged so that they project the light pattern from the micromirror array onto the screen. Projection TV according to one of claims 61 to 83, which further comprises one or more lenses, around a cone of light to focus and focus on the micromirror array. Projection TV according to one of claims 61 to 84, in which several vertical lines, which are a set of addressing columns correspond, emanating from respective micromirrors in the line and are connected to every other row of micromirrors; and or where horizontal lines corresponding to addressing lines emanating from respective micromirrors in the column and with each second column of micromirrors are connected. Projection TV according to one of claims 61 to 85, where the micromirror metal and a dielectric material wherein the dielectric material is a nitride, carbide or Oxide of silicon is. Projection TV according to one of claims 73 to 86, where the case a hermetic housing is. Projection TV according to one of claims 61 to 87, with HDTV format. Projection TV according to one of claims 61 to 87, with QXGR format. Projection TV according to one of claims 61 to 87, with UXGR format. Projection TV according to one of claims 73 to 80, where the case has an array of circuits and electrodes on a semiconductor substrate, and several bonding wires to electrical connection of the substrate to the housing. Projection TV according to one of claims 61 to 91, in the joints of the micromirror parallel to the front and backs of the micromirror array. Projection TV according to one of claims 61 to 92, in which 2,000,000 to 3,000,000 micromirrors are provided in the array are. A projection TV according to any one of claims 61 to 93, wherein the micromirror array has an area of 1 cm ² to 1 in ² . Projection TV according to one of claims 61 to 94, where the micromirror has a resolution of 1,920,000 or more having. Projection TV according to one of claims 61 to 95, in which each micromirror has a switching axis, which in the is substantially parallel to at least one side of the array. Projection TV according to one of claims 61 to 96, wherein each micromirror has a switching axis, the an angle of 35 to 60 degrees to all sides of the micromirror lies. Projection TV according to one of claims 61 to 97, in which the light beam perpendicular to any sides of the micromirror incident. Projection TV according to one of claims 61 to 98, which further comprises a TIR prism. Projection TV according to one of claims 61 to 99, further comprising a light absorbing layer under the micromirrors exhibits light scattering through the gaps between the micromirrors to reduce. Projection TV according to one of claims 61 to 92, 94 and 96 to 100, with 64,000 to 2,000,000 micromirrors are provided in the array. Rear-projection TV, full: an arc lamp for supplying light to a light modulator, having a rectangular array of micromirrors; in which the micromirrors of the array are tiled, and each micromirror has four substantially rectilinear sides, and wherein the micromirrors are substantially square; one Screen on which an image to be viewed is displayed; in which while In operation, a beam of light from the arc lamp on the array Micro mirrors occurs and as a rectangular image is directed to the screen; in which The micromirrors of the array are capable of changing through pulse width modulation to move between an off-state and an on-state to create an image on the screen; where both the as well as the off states the micromirror is in positions that are from an undeflected one State are different; being the on-position of the micromirrors 10 to 15 degrees with respect a non-deflected position; where none of the four essentially straight sides of the micromirrors parallel to one the sides of the array; where the picture considered four Has sides; wherein the micromirror array is a substantially rectangular one Having shape; one or more lenses, around a beam of light to focus and focus on the micromirrors; the Light beam at an angle of substantially 90 degrees to at least one side of the rectangular array is incident; being on the Micromirror incident light beam 10 to 50 degrees with respect to one Having line perpendicular to the plane of the micromirrors, if they are not deflected; wherein the micromirrors are micromirror plates include that over Joints are connected to a substrate; the substrate, the micromirror plates and the joints in different planes are arranged; wherein the micromirrors are positioned on a grid, which is inclined to the sides of the rectangular array; in which the micromirrors are arranged on a semiconductor substrate, the a silicon substrate; where the micromirrors are over underlying Joints with the silicon substrate by an electrically conductive material are connected; the micromirror on the silicon substrate with circuits and electrodes adjacent to the micromirrors are trained; at least two for each micromirror Electrodes are adjacent, one of the two electrodes for the Electrostatic control of the adjacent micromirror in one Off position provided and another of the two electrodes for electrostatic drive the adjacent micromirror in an on position; in which the light is directed at an angle substantially perpendicular lies to the switching axis of the micromirror; being the micromirror in the array switching axes, which at an angle of 35 to 60 degrees to one or more sides of the micromirrors; in which the micromirrors have substantially no micromirror sides, perpendicular to the incident light beam from the light source lie; wherein the micromirror comprises a reflective material, comprising aluminum; in which the micromirror array in a housing with a translucent window is arranged, wherein the translucent window of glass or quartz consists; wherein the micromirror array is an array of circuits and electrodes on a semiconductor substrate, and a Set of bonding wires for electrically connecting the semiconductor substrate to the housing; and in which the projection TV further comprises multi-lens optics, which are arranged to reflect the light reflected from the micromirrors to project onto the screen. Rear-projection TV The device of claim 102, wherein the micromirrors are capable of to rotate at least +12 degrees to the on position. Rear-projection TV according to one of the claims 102-103, with 64,000 to 2,000,000 micromirrors in the array are provided. Rear-projection TV according to one of the claims 102 to 104, with HDTV format. Rear-projection TV according to one of the claims 102 to 104, with QXGA or UXGA format. Rear-projection TV according to one of the claims 102, 103, 105 and 160, wherein the micromirror has a resolution of Has 1,920,000 or more. Rear-projection TV according to one of the claims 102 to 107, in which a color filter is provided to one row of sequential colors to form on the micromirror array. Rear-projection TV according to one of the claims 102 to 108, wherein a mask is provided as part of the housing. Rear-projection TV according to one of the claims 102 to 109, further comprising a TIR prism or total internal reflection prism. Rear-projection TV according to one of the claims 102 to 110, in which a horizontal row of micromirrors extends from corner to corner in the row parallel to one side of the micromirror array, and where vertical lines corresponding to addressing columns emanating from respective micromirrors in the line and with each second row of micromirrors are connected. Rear-projection TV according to one of the claims 102 to 111, in which a vertical column of micromirrors from corner to corner in the column parallel to one side of the micromirror array extends, and in the horizontal lines, the addressing lines correspond from respective micromirrors in the column and connected to every other column of micromirrors. Rear-projection TV according to one of the claims 102 to 112, in which the rectangular array has two longer sides and two shorter ones Has sides, and wherein the light beam at an angle of essentially 90 degrees a shorter one Side of the rectangular array. Rear-projection TV according to one of the claims 102 to 113, in which the thickness of the micromirror plate is between 200 and 7300 angstroms. A rear projection TV according to any one of claims 102 to 114, wherein the micromirror array has an area of 1 cm ² to 1 in ² . Rear-projection TV according to one of the claims 102 to 115, in which in the housing a source of a static friction reducing agent is provided. Rear-projection TV according to one of the claims 102 to 116, in which the joint has a width between 0.1 and 10 Having micrometer. A rear projection TV according to any one of claims 102 to 117, wherein the micromirror array has an area of 1 cm ² to 1 in ² . Rear-projection TV according to one of the claims 102 to 118, where the case hermetic. Rear-projection TV according to one of the claims 102 to 119, in which in the housing a getter is provided. Rear-projection TV according to one of the claims 102 to 120, in which in the housing a source of a static friction reducing agent is provided.