WO2002042825A1 - Dispositif et systeme de modulation de la lumiere - Google Patents

Dispositif et systeme de modulation de la lumiere Download PDF

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Publication number
WO2002042825A1
WO2002042825A1 PCT/US2001/043560 US0143560W WO0242825A1 WO 2002042825 A1 WO2002042825 A1 WO 2002042825A1 US 0143560 W US0143560 W US 0143560W WO 0242825 A1 WO0242825 A1 WO 0242825A1
Authority
WO
WIPO (PCT)
Prior art keywords
flexible member
electrodes
state
electrode
mirror
Prior art date
Application number
PCT/US2001/043560
Other languages
English (en)
Inventor
Wenhui Mei
Kin Foong Chan
Dong Youn Sim
Original Assignee
Ball Semiconductor, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US09/718,619 external-priority patent/US6433917B1/en
Priority claimed from US09/728,691 external-priority patent/US6512625B2/en
Application filed by Ball Semiconductor, Inc. filed Critical Ball Semiconductor, Inc.
Publication of WO2002042825A1 publication Critical patent/WO2002042825A1/fr

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Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/35—Optical coupling means having switching means
    • G02B6/351—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements
    • G02B6/3512—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements the optical element being reflective, e.g. mirror
    • G02B6/3518—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements the optical element being reflective, e.g. mirror the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
    • G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
    • G02B26/0841—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD the reflecting element being moved or deformed by electrostatic means
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70216—Mask projection systems
    • G03F7/70283—Mask effects on the imaging process
    • G03F7/70291—Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70375—Multiphoton lithography or multiphoton photopolymerization; Imaging systems comprising means for converting one type of radiation into another type of radiation
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/35—Optical coupling means having switching means
    • G02B6/354—Switching arrangements, i.e. number of input/output ports and interconnection types
    • G02B6/3544—2D constellations, i.e. with switching elements and switched beams located in a plane
    • G02B6/3546—NxM switch, i.e. a regular array of switches elements of matrix type constellation
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/35—Optical coupling means having switching means
    • G02B6/3564—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details
    • G02B6/3568—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details characterised by the actuating force
    • G02B6/357—Electrostatic force
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/35—Optical coupling means having switching means
    • G02B6/3564—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details
    • G02B6/3582—Housing means or package or arranging details of the switching elements, e.g. for thermal isolation
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/35—Optical coupling means having switching means
    • G02B6/3564—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details
    • G02B6/3584—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching

Definitions

  • the present invention relates generally to optical devices and optical systems, and more particularly to a device for modulating a light beam intensity and a projector/exposure system using such a device.
  • phase modulation is often more important than amplitude modulation.
  • phase modulation devices can often perform amplitude modulation, thereby providing application flexibility. It is desired to provide a light modulation device that is fast, reliable, durable, efficient, and can be used in simple as well as complex applications.
  • the light element includes three electrodes, a support structure, a flexible member, and a mirror.
  • the flexible member is connected to the support structure so that it is responsive to electrostatic forces provided by one or more of the three electrodes.
  • the flexible member is positioned in a gap so that it can move between a first and second state, responsive to the electrostatic forces.
  • the mirror is also attached to the flexible member, so that it too moves between a first and second state.
  • the light element includes first, second, and third electrodes positioned adjacent to a substrate, each electrode capable of producing a force.
  • Two support members are also connected to the substrate and a flexible member spans there between, extending over and above the three electrodes and capable of moving between a first and second state.
  • a mirror is connected to and extends above the flexible member.
  • the light element includes a first, second, and third electrode for producing a first, second and third force, respectively.
  • a flexible member which is responsive to a force, is connected to a support structure.
  • a mirror is further attached to the flexible member. In operation, the flexible member, and hence the mirror, transition between different states responsive to various combinations of the first, second, and third forces.
  • the light element includes two electrodes connected to the substrate for producing an electrostatic force and a flexible member suspended over the two electrodes.
  • An actuator and a third electrode are also included, the actuator being adjacent the flexible member.
  • the first two electrodes are situated to hold the flexible member in a prior state responsive to a hold voltage applied thereto, and the actuator is situated to selectively move the flexible member between two operational states.
  • Figs. 1, 4, and 9 are side, cross sectional views of several different embodiments of light modulating elements according to the present invention.
  • Figs. 2- 3 illustrate different states of the light modulating element of Fig. 1.
  • Fig. 5 illustrates another state of the light modulating element of Fig. 4.
  • Figs. 6-7 are exploded views of the light modulating element of Fig. 4.
  • Fig. 8 is a graph illustrating the operation of the light modulating element of Fig. 4.
  • Fig. 10 illustrates another state of the light modulating element of Fig. 9.
  • Fig. 11 is an exploded view of the light modulating element of Fig. 9.
  • Figs. 12-16 are isometric views of one embodiment of several light modulation elements that are part of a single micro-mirror light modulating device, according to the present invention.
  • Figs. 17-18 are cross sectional views of different embodiments of a projection system, utilizing one or more of the light modulation devices discussed in Figs. 12-16.
  • the present disclosure relates to optical devices and optical systems, such as can be used in a wide variety of applications. It is understood, however, that the following disclosure provides many different embodiments, or examples, for implementing different features of the invention in specific applications. These embodiments are, of course, merely examples and are not intended to limit the invention from that described in the claims.
  • the present disclosure is divided into five different sections.
  • the first section describes an element for light phase modulation.
  • the second section describes a light phase modulation device including several of the elements.
  • the third section describes different applications for the light phase modulation device.
  • the fourth section describes embodiments of a tilting light modulation device and various applications thereof.
  • the fifth section concludes by describing some of the many advantages of the elements, devices, and applications previously discussed.
  • a component layout for one embodiment of a light modulation element 10 is shown.
  • the light modulation element 10 is constructed on a semiconductor substrate 12.
  • Two electrodes 14, 16 are formed adjacent to the substrate 12.
  • Each electrode is, in the present embodiment, a solid film of electrically conductive material, such as metal.
  • the electrodes 14, 16 are positioned between non-conductive support structures 18.
  • the support structures 18 secure a flexible, spring-like member 20, which is also responsive to electrostatic fields.
  • the flexible member 20 is further connected to a mirror 22 through a connecting portion 24.
  • the mirror may be of many different types of reflective materials, such as gold, aluminum, copper, or a combination thereof, depending on the use (e.g., infrared, x-ray) for the light modulation element 10.
  • the support structures 18 also secure a third electrode 26.
  • the light modulation element 10 is a micro-electro-mechanical (MEM) device, and therefore has several gap areas to allow mechanical movement.
  • a first area 30 is defined between the electrodes 14,
  • a second area 32 is defined between the flexible member 20 and the third electrode 26.
  • a third area 34 is defined between the third electrode 26 and the mirror 22.
  • a sacrificial layer can be fabricated into the areas, and then later removed by an appropriate vapor etch. As shown in Fig. 1, a distance dl is provided between the flexible member 20 and the second electrode 16; a distance d2 is provided between the flexible member 20 and the third electrode 26; and a distance d3 is provided between the third electrode 26 and the mirror 22.
  • the distances dl, d2, d3 can vary, depending on different materials used (e.g., for the flexible member 20) or other factors, in the present embodiment, the distances are defined by equations (1) and (2), below. dl, d3 » d2. (1) d3 ⁇ dl (2)
  • the distances dl, d2, d3 will be related to a wavelength ⁇ of light being reflected off of the mirror 22.
  • a light source may have a wavelength ⁇ of 400 nano-meters (nm).
  • the distances dl, d3 could be equal to lOOnm and the distance d2 could be about 5-10nm.
  • the light modulation element 10 can be in three different mechanical states.
  • Fig. 1 illustrates a "free" state in which the flexible member 20 is in a natural, un- flexed state.
  • the distance d2 is relatively small, and the distances dl, d3 are relatively large.
  • ⁇ Fig. 2 illustrates an "upper" state in which the flexible member 20 is flexed upward, as seen in the figure, and away from the substrate 12.
  • the distance d2 is approximately equal to zero and the distances dl, d3 are larger than they were in the free state. In many applications, the difference between the upper and free states can be considered as insignificant.
  • Fig. 3 illustrates a "lower" state in which the flexible member 20 is flexed downward, as seen in the figure, and toward the substrate 12.
  • the distances dl, d3 are approximately equal to zero and the distance d2 is now relatively large.
  • the three states - free, upper, and lower - are defined by electrostatic forces applied between the three electrodes 14, 16, 26 and/or the flexible member 20.
  • the flexible member 20 is at a first voltage and the electrodes 14, 16, 26 can selectively alternate between the first voltage and a second voltage.
  • the first voltage will be ground, designated with a binary "0”
  • the second voltage will represent a positive voltage, designated with a binary "1”.
  • the positive voltage 1 will electrostatically attract an item at the ground voltage 0. It is understood, however, that various combinations of different voltages can produce different operations, so that the present invention can facilitate many different design choices well understood by those of ordinary skill in the art.
  • the light modulation element 10 can also be in a "hold" state.
  • the hold state maintains a prior state of the element 10, despite changes in electrode voltage. Simply put, the hold state serves as a memory for the element 10. The hold state will be discussed in greater detail, below.
  • the light modulation element 10 can operate in many different configurations of the electrodes 14, 16, 26. Referring now to Table 1, in one configuration, each of the electrodes 14, 16, 26 can operate independently of the others.
  • electrodes 14 and 16 are 1 and that the light modulation element 10 is currently in the lower state, meaning that the distance d3 is small, and the mirror 22 is in the lower position.
  • electrode 26 switches to 1.
  • the light modulation element 10 will be in the hold state. In the present example, the hold state will "hold” the previous state, so that the mirror 22 stays in the lower state.
  • electrode 26 switches to 0.
  • the light modulation element 10 will still be in the hold state. This means that the previous lower state continues to be held. Therefore, as long as the electrodes 14 and 26 stay at 1, the lower state will be held. Many different scenarios can be shown to hold the free state or the upper state.
  • the light modulation element 10 is able to hold a certain state by controlling the strength of the electrostatic fields produced from the electrodes 14, 16 and/or 26.
  • the strength of the electrostatic fields that are affecting the flexible member 20 are manipulated by the distances dl, d2, and/or d3.
  • the strength of the fields can be manipulated in many different ways.
  • the strength of the corresponding electrostatic fields can be manipulated by the size of the electrodes 14, 16, and/or 26, the material used to construct each electrode, the voltage applied to each electrode, and/or any intervening structures.
  • electrode 16 can also be used as an edge-trigger input. For example, if electrode 14 is 0 and electrodes 16 and 26 are 1, the light modulation element 10 will be in the hold state. However, if electrode 16 switches to 0, the light modulation element 10 will switch to the upper state. If electrode 16 switches back to 1, the light modulation element 10 will be held in the upper state. Therefore, after every change of electrode 16, the light modulation element will be in the upper state. This works in a similar manner for the lower state and the hold state.
  • electrodes 14 and 26 are tied together, and electrode 16 can operate independently of the other two.
  • the electrodes 14, 26 are treated together as a "hold electrode", placing the light modulation element 10 in and out of the hold state.
  • the electrode 16 acts as a "data electrode", with the free state corresponding to a 0 value and the lower state corresponding to a 1 value.
  • a component layout for another embodiment of a light modulation element 60 is shown. Components of the element 60 that can be similar to those of the element 10 (Fig. 1) are commonly numbered.
  • the light modulation element 60 is constructed on a semiconductor substrate 12. Three electrodes 62, 64, 66 are formed adjacent to the substrate 12, although different embodiments may include an insulative material (not shown) to facilitate electrical isolation. Each electrode is, in the present embodiment, a solid film of electrically conductive material, such as metal.
  • the electrodes 62-66 are positioned between non-conductive support structures 68.
  • the support structures 68 secure a flexible spring-like member 70.
  • the flexible member 70 is non-linear, which means that it has a tendency to "pop" into either of two states, as will be discussed in greater detail, below.
  • the flexible member 70 is further connected to a mirror 22 through a connecting portion 24.
  • the mirror may be of many different types of reflective materials, such as gold, aluminum, copper, or a combination thereof, depending on the use (e.g., infrared, x-ray) for the light modulation element 60.
  • the light modulation element 60 is also a MEM device, and therefore also has several gap areas to allow mechanical movement.
  • a first area 72 is defined between the three electrodes 62-66 and the flexible member 70.
  • a second area 74 is defined between the flexible member 70 and the mirror 22.
  • a distance d4 is provided between the flexible member 70 and the electrodes 62-66.
  • the distance d4 can be considered similar to the distance dl of Fig. 1.
  • the light modulation element 60 can be in two different mechanical states.
  • Fig. 4 illustrates a free state in which the flexible member 70 is in a natural, un-flexed state.
  • the distance d4 is relatively large.
  • the free state is also considered the upper state.
  • Fig. 5 illustrates a lower state in which the flexible member 70 is flexed downward, as seen in the figure, and towards the substrate 12. As shown in Fig. 5, the distance d4 is approximately equal to zero.
  • the flexible member 70 includes two different sub-components.
  • a plurality of flexible legs 70a are provided, each connected to one of the support structures 68.
  • the flexible legs 70a meet at a central portion 70b, which is further connected to the mirror 22 through the connecting portion 24.
  • the central portion 70b is made of a material that is responsive to electrostatic fields caused by one or more of the electrodes 62-66.
  • the flexible legs 70a and the central portion 70b are configured to provide a non-linear flexing action (the "pop").
  • the first electrode 62 has an area Al under the central portion
  • the second electrode 64 has an area A2 under the central portion
  • the third electrode 66 has an area A3 under the central portion.
  • the areas are such that:
  • the amount of electrostatic force produced by each electrode 62-66 can be controlled.
  • the electrostatic force can be controlled by other means, such as voltage level or material composition of each electrode. Also in other embodiments, it may be desirable to have different electrostatic forces associated with each electrode.
  • a graph 76 illustrates the operation of the light modulation element 60.
  • a vertical axis labeled “Displacement” shows a position for the central portion 70b of the flexible member 70, and thus the position of the mirror 22.
  • a horizontal axis labeled “Electrostatic Voltage”, shows a value for the voltages of the three electrodes 62-66.
  • the graph 76 includes two curves 78d, 78u.
  • the curve 78d represents a downward motion for the flexible member 70, and the curve 78u represents an upward motion for the flexible member.
  • the curves 78u, 78d illustrate an operational hysteresis for the flexible member 70.
  • the lower state of the flexible member 70 may be controlled by a mechanical stopper, such as is discussed in greater detail with respect to Fig. 10, below.
  • the electrodes 62, 64, 66 are capable of providing a voltage VI, V2, V3, respectively.
  • the first electrode 62 (with the voltage VI) serves as a data electrode
  • the second electrode 64 (with the voltage V2) serves as an "active electrode”
  • the third electrode 66 (with the voltage V3) serves as a "lock/reset electrode.”
  • a value V TH1 is a threshold voltage where there is sufficient electrostatic force to pop the flexible member 70 from the upper state (Fig. 4) to the lower state (Fig. 5).
  • a value V TH2 is a threshold voltage where there is sufficient electrostatic force to release (or “unpop") the flexible member 70 from the lower state back to the upper state.
  • the voltages VI, V2, V TH1 , V TH2 , and a total voltage V ⁇ o ⁇ are defined by the following relationships: v ⁇ o ⁇ — VI + V2 + V3 (4) ⁇ 1 > (V3 + V2) (5)
  • the light modulation element 60 can operate in many different configurations of the electrodes 62-66. Referring now to Table 4, in one configuration, each of the electrodes 62-66 can operate independently of the others. Table 4 utilizes the 0/1 voltage designations discussed above, with the 0 voltage designation representing zero volts, and the 1 voltage designation representing either VI, V2, or V3, as identified above.
  • Table 4 supports two distinct operations: writing a data value from the first electrode 62, and holding the data value previously written.
  • the element is first reset by setting all three electrodes 62-66 to zero. When the element 60 resets, it is in the free or upper state. Then, the third electrode 66 is set to 1 (thereby locking the element) and the second electrode 64 is set to 1 (thereby activating the element). At this time, the element 60 will be responsive to the data (0 or 1) from the first electrode 62.
  • the third electrode 66 is set to 1 and the second electrode 64 is set to 0. At this time, the element 60 will not be responsive to the data in the first electrode 62, and the state of the element will remain unchanged.
  • the third electrode 66 remains locked (set to 1) at all times, except when the element 60 is being reset.
  • the second electrode 64 is active (set to 1) when it is desired that the element 60 be responsive to data from the first electrode 62, and inactive (set to 0) when it is desired that the element not be responsive to data from the first electrode.
  • a component layout for yet another embodiment of a light modulation element 80 is shown.
  • Components of the element 80 that can be similar to those of the elements 10 (Fig. 1) and 60 (Fig. 4) are commonly numbered, hi the present embodiment, the light modulation element 80 is constructed on a semiconductor substrate 12.
  • Two electrodes 82, 84 are formed adjacent to the substrate 12.
  • Each electrode 82, 84 is, in the present embodiment, a solid film of electrically conductive material, such as metal.
  • the electrodes 82-84 are positioned between non-conductive support structures 86.
  • the support structures 86 secure a flexible member 88.
  • the flexible member 88 is further connected to a mirror 22 through a connecting portion 24.
  • the light modulation element 80 is also a MEM device, and therefore also has several gap areas to allow mechanical movement.
  • a first area 90 is defined between the two electrodes 82-84 and the flexible member 88.
  • a second area 92 is defined between the flexible member 88 and the mirror 22.
  • a distance d4 is provided between the flexible member 88 and the electrodes 82-84.
  • nonconductive stopper devices 93 may be attached to the electrodes 82-84. The stopper devices 93 serve to limit the movement of the flexible member 88 and to prevent contact between the electrode 82 and the flexible member.
  • a third electrode 94 extends above the flexible member 88. Unlike the element 100 of Fig.
  • the third electrode 94 is separated from the flexible member 88 by an isolation layer 96.
  • the isolation layer 96 may serve as an electrical isolator and/or a thermal isolator, as needed. In some embodiments, the isolation layer 96 is used throughout the element 80.
  • an actuator 98 is positioned adjacent to the flexible member 88 and adjacent to the third electrode 94.
  • the actuator 98 is capable of placing the light modulation element 80 in two different states: free and lower.
  • Fig. 9 illustrates the free state in which the flexible member 88 is in a natural, un-flexed state. As shown in Fig. 9, the distance d4 is relatively large. In the present embodiment, the free state is also considered the upper state.
  • Fig. 10 illustrates the lower state in which the flexible member 88 is flexed downward, as seen in the figure, and towards the substrate 12. As shown in Fig. 10, the distance d4 is approximately equal to zero.
  • the actuator 98 is triggered by the third electrode 94.
  • the actuator 98 is a PZT thin film micro-actuator.
  • the PZT actuator 98 utilizes piezoelectric effects to move the flexible member 88 to the lower state.
  • the actuator 98 is a thermal type, or "pyroelectric" actuator.
  • the pyroelectric actuator 98 utilizes the thermal expansion of thin films to move the flexible member 88 to the lower state. Therefore, in response to a voltage/current signal on the third electrode
  • the actuator 98 (piezoelectric or pyroelectric) fluctuates between the two states illustrated in Figs. 9 and 10.
  • the flexible member 88 includes two different sub-components.
  • a plurality of flexible legs 88a are provided, each connected to one of the support structures 68.
  • the flexible legs 88a meet at a central portion 88b, which is further connected to the mirror 22 through the connecting portion 24.
  • Each flexible leg 88a includes the isolation layer 96, the actuator 98, and the third electrode 94.
  • the central portion 88b is made of a material that is responsive to electrostatic fields caused by one or more of the electrodes 82-84.
  • the flexible legs 88a move responsive to the actuator 98, and thereby move the central portion 88b between the upper (free) and lower states. It is understood that there are many configurations of the flexible legs 88a, central portion
  • the light modulation element 80 can operate in many different configurations of the electrodes 82, 84, 94. Referring now to Table 5, in one configuration, each of the electrodes 82, 84, 94 can operate independently of the others.
  • the element 80 operates similarly to the element 10 discussed with reference to Table 1. It is noted, however, that the upper state and the free state are the same for the element 80.
  • electrodes 82 and 94 are tied together, and electrode 84 can operate independently of the other two.
  • the electrodes 82 and 94 both have the 1 voltage
  • the light modulation element 80 is in the hold state, regardless of the voltage for electrode 84. Therefore, the electrodes 82, 94 are treated together as a hold electrode, placing the light modulation element 80 in and out of the hold state.
  • the electrode 84 acts as a data electrode, with the free state corresponding to a 0 value and the lower state corresponding to a 1 value.
  • the light modulation elements 10, 60 and 80 can perform in many different ways, and can be combined to accommodate different applications, some of which are discussed below.
  • a plurality of light modulation elements can be configured into an array on a single monolithic substrate 90 to produce a micro-mirror light modulation device 92.
  • Any of the above-mentioned light modulation elements can be used, in any combination.
  • 20 light modulation elements 10 are arranged in an array of five rows R(0), R(l), R(2), R(3), R(4), and four columns C(0), C(l), C(2), C(3).
  • Conventional SRAM, DRAM, and DMD data and addressing schemes can be utilized to implement these larger arrays, as would be evident to those of ordinary skill in the art. For example, separate column and row address may be multiplexed, as is used in many DRAM architectures. Also, a clock or latch signal can be utilized to synchronize operation.
  • the light modulation elements 10 of the light modulation device 92 are configured as discussed in Table 3, above. Specifically, the first and third electrodes 14, 26 for each light modulation element 10 are electrically connected to form a hold electrode. In addition, all of the data electrodes 16 for light modulation elements on a common row are electrically connected. The data electrodes for rows R(0) - R(4) are connected to data lines D(0) - D(4), respectively. The data lines D(0..4) are further connected to data inputs of the device 92, with any intermediate circuitry (e.g., registers or buffers) as necessary. Likewise, all of the hold electrodes 14, 26 for light modulation elements on a common column are electrically connected.
  • the hold electrodes for columns C(0) - C(3) are connected to hold lines H(0) - H(3), respectively.
  • the hold lines H(0..3) are further connected to an address decoder of the device 92, which may be further connected to address inputs and additional circuitry, as necessary.
  • Figs. 12-16 illustrate a sequence of operations for individually manipulating each light modulation element 10 of the light modulation device 92. It is understood that if the light modulation device 92 is constructed with the elements 80 discussed in Fig. 9, the operation will be essentially the same as discussed below. If the light modulation device 92 is constructed with the elements 60 discussed in Fig. 4, additional and/or modified signals will need to be provided, as discussed above with reference to Table 4.
  • D(0..4) 10110 is provided to the device 92.
  • the hold line H(0) is then asserted (set equal to 1).
  • the state for the light modulation elements 10 of column C(0) are as in Table 7, below.
  • the voltage levels of the remaining hold lines H(l .. 3) are a "don't care" in the present example, and may be of different values according to different implementations.
  • D(0..4) 01101 is provided to the device 92.
  • the hold line H(l) is then asserted (the hold line H(0) remains asserted).
  • the state for the light modulation elements 10 of column C(0..1) are as in Table 8, below.
  • D(0..4) 11100 is provided to the device 92.
  • the hold line H(2) is then asserted (the hold lines H(0..1) remain asserted).
  • the state for the light modulation elements 10 of column C(0..2) are as in Table 9, below.
  • D(0..4) 01010 is provided to the device 92.
  • the hold line H(3) is then asserted (the hold lines H(0..2) remain asserted).
  • Table 10 the state for all the light modulation elements 10 of device 92 is provided in Table 10, below.
  • D(0..4) 01001 is provided to the device 92.
  • the hold line H(0) is then asserted (the hold lines H(1..3) remain asserted).
  • the state for all the light modulation elements 10 of device 92 is provided in Table 11, below.
  • the light modulation device 92 can easily address and store data in each element 10 without the use of any additional memory. Also, it is understood that different light modulation devices can be constructed, such as those that utilize the operation of the light element 10 discussed in Tables 1 and 2, above.
  • the light modulation elements 10, 60, 80 and the light modulation device 92 can be used in many different applications.
  • the elements work well for high light intensity applications as well as short wavelength applications, such as is discussed in U.S. Patent No. 5,986,795, which is hereby incorporated by reference.
  • the light modulation device 92 works for soft x-ray applications as well as extreme ultra-violet (or "EUV") lithography with wavelengths of 100 nm or less.
  • EUV extreme ultra-violet
  • the mirror 22 may be constructed with a multilayer reflective coating, including but not limited to alternate coatings of molybdenum and silicon, such as is discussed in U.S. Patent No. 6,110,607, which is hereby incorporated by reference.
  • the light modulation elements 10, 60, 80 and the light modulation device 92 can also operate as optical communication devices.
  • individual light beams can be manipulated for dense wavelength division multiplexing ("DWDM”).
  • DWDM dense wavelength division multiplexing
  • OADM optical add/drop modules
  • these elements and devices can be used for digital color displays and the like.
  • the light modulation device 92 can be used as part of a projector system 100.
  • the projector system 100 also includes a light source 102, a beam- splitter 104, a mirror 106, and a lens system 108 for projecting an image onto a surface 110.
  • the image from the projector system 100 is defined by a plurality of pixels, corresponding to the number of light modulation elements 10 on the light modulation device 92 (or multiples thereof).
  • the light source 102 may produce either coherent or non-coherent light. Certain applications can benefit by using a cheaper non-coherent light source.
  • the light source 102 produces light of a wavelength ⁇ .
  • each mirror 22 of the device 92 can move a distance of ⁇ /4 between the free state and the lower state.
  • the lens system 108 is illustrated as a single lens, but it is understood that various combinations may be employed, to meet various design choices.
  • the beamsplitter 104 includes a reflective surface 112 positioned between two transparent prisms 114, 116.
  • the reflective surface 112 is a 50/50 splitter, in that half of the light intensity is allowed to pass directly tlirough the reflective surface, while the other half reflects off the reflective surface, hi some embodiments, the reflective surface may be a dichroic mirror, having different reflecting and/or passing characteristics responsive to the wavelength of incident light. Also in the present embodiment, the mirror 106 can reflect 100% of incident light. It is understood, however, that different applications may utilize different mirrors, beamsplitters, or other similar items.
  • the beamsplitter 104 is also positioned, with the light modulation device 92 and the mirror 106, so that a perpendicular distance from the mirror 106 to a point on the reflective surface 112 is equal to a perpendicular distance from a mirror 22 (in the free state) of a corresponding light modulation element 10 to the same point.
  • This perpendicular distance is determined when the corresponding light modulation element is in the free state. It is understood, that in other embodiments, the perpendicular distance may be determined when the light modulation element is in a different state.
  • the logic discussed below will need to be altered, accordingly. It is further understood that in additional embodiments (e.g., laser applications), the distances for the mirror 22 and the mirror 106 to the reflective surface may be different.
  • the beam 120.1 reflects off of the reflective surface 112 and onto the mirror 22a of light modulation element 10a. In this example, the light modulation element 10a is in the free state.
  • the beam 120.1 then reflects back towards the reflective surface 112.
  • the beam 120.2 passes through the reflective surface and onto the mirror 106.
  • the beam 120.2 then reflects back towards the reflective surface 112.
  • the overall distance that beam 120.1 travels is exactly equal to the overall distance that beam 120.2 travels. Therefore, when the beams 120.1, 120.2 meet again at the reflective surface 112, they constructively add to produce an output beam 120.3 with a significant amplitude (referred to as "ON") and directly in phase with the light beam 120.1.
  • the light beam 120.3 then passes through the lens system 108 and projects a pixel onto a point PI of the surface 110.
  • a beam 122 being projected towards the beam splitter 104.
  • the beam 122 reaches the reflective surface 112
  • two separate beams 122.1, 122.2 (each 50% the intensity of beam 122) are produced.
  • the beam 122.1 reflects off of the reflective surface 112 and onto the mirror 22b of light modulation element 10b.
  • the light modulation element 10a is in the lower state.
  • the beam 122.1 then reflects back towards the reflective surface 112.
  • the beam 122.2 passes through the reflective surface and onto the mirror 106.
  • the beam 122.2 then reflects back towards the reflective surface 112.
  • the overall distance that beam 122.1 travels is exactly half a wavelength ( ⁇ /4 + ⁇ /4 ) more than the overall distance that beam 122.2 travels. Therefore, when the beams 122.1,
  • two light modulation devices 92a, 92b can be used as part of another projector system 150.
  • the projector system 150 is similar to the projector system 100 of Fig. 17, with identical components number consistently. It is noted, however, that the projector system 150 includes the second light modulation device 92b where the mirror 106 of the previous system 100 was located.
  • the projector system 150 includes the additional ability to selectively alter the phase of the light from the light source 102.
  • the beamsplitter 104 is now positioned with the light modulation devices 92a, 92b, so that a perpendicular distance from a point on the reflective surface
  • 112 to corresponding light modulation elements of the light modulation devices is a multiple of ⁇ /2, when that light modulation element is in the lower state (this example is opposite to the one of Fig. 17).
  • a beam 152 being projected towards the beam splitter 104.
  • two separate beams 152.1, 152.2 are produced.
  • the beam 152.1 reflects off of the reflective surface 112 and onto the mirror 22c of light modulation element 10c (of light modulation device 92a).
  • the beam 152.1 then reflects back towards the reflective surface 112.
  • the beam 152.2 passes through the reflective surface and onto the mirror 22d of light modulation element lOd (of light modulation device 92b).
  • the beam 152.2 then reflects back towards the reflective surface 112.
  • the light modulation elements 10c, lOd are in the same state. Therefore, the overall distance that the beam 152.1 travels is exactly the same as the overall distance that beam 152.2 travels.
  • the beams 152.1, 152.2 then meet again at the reflective surface 112, where they constructively add to produce an output beam 152.3 that is ON.
  • the light beam 152.3 then passes through the lens system 108 and projects a pixel onto a point P3 of the surface 110.
  • this distance traveled by the beams 152.1 and 152.2 is different for different states of the light modulation elements 10c, lOd.
  • both beams 152.1, 152.2 have traveled a half wavelength ( ⁇ /4 + ⁇ /4 ) less than if both light modulation elements are in the lower state. Therefore, when the beams 152.1, 152.2 meet again at the reflective surface 112, they may be exactly in phase with the incident beam 152.1, or may be 180° out of phase with the beam.
  • a component layout for another embodiment of a light modulation element 200 is shown. Components of the element 200 that can be similar to those of the element 10 (Fig. 1) are commonly numbered.
  • the light modulation element 200 is constructed on a semiconductor substrate 12. Three electrodes 202, 204, 206 are formed adjacent to the substrate 12, although different embodiments may include an insulative material (not shown) to facilitate electrical isolation. Each electrode is, in the present embodiment, a solid film of electrically conductive material, such as metal.
  • the electrodes 202-206 are positioned between non-conductive support structures 208.
  • the support structures 208 secure a rigid member 210 through torsional stabilizers (not shown). The torsional stabilizers will be discussed in greater detail, below.
  • the rigid member 210 is further connected to a mirror 22 through a connecting portion 24.
  • the mirror may be of many different types of reflective materials, such as gold, aluminum, copper, or a combination thereof, depending on the use (e.g., infrared, x-ray) for the light modulation element 200.
  • the light modulation element 200 is also a MEM device, and therefore also has several gap areas to allow mechanical movement.
  • a first area 212 is defined between the three electrodes 202-206 and the rigid member 210.
  • a second area 214 is defined between the rigid member 210 and the mirror 22. As shown in Fig. 4, distances d5, d6 are provided between the rigid member 210 and the electrodes 202, 206, respectively.
  • the light modulation element 200 can be in three different mechanical states.
  • Fig. 4 illustrates a free state in which the rigid member 210 is parallel with the substrate 12. As shown in Fig. 4, the distances d5, d6 are relatively equal. In the present embodiment, the free state is also considered the planar state.
  • Fig. 20 illustrates a left tilt state in which the rigid member 210 is tilted leftward, as seen in the figure. As shown in Fig. 5, the distance d5 is approximately equal to zero and the distance d6 is relatively large. Although not shown, a right tilt state is also possible, with the distance d6 approximately equal to zero and the distance d5 relatively large.
  • Figs. 21-23 and Figs. 24-26 illustrate two different embodiments for the light modulation element 200.
  • the rigid member 210 rotates about an axis al in a parallel configuration with the other components.
  • the rigid member 210 rotates about an axis a2 in a diagonal configuration with the other components.
  • the first electrode 202 extends longitudinally, as shown in the figure, and the second and third electrodes 204, 206 extended latitudinally across the substrate 12.
  • the electrodes 202-206 include sufficient area to facilitate an electrostatic force for attracting the rigid member 210.
  • the electrostatic force can be controlled by other means, such as voltage level or material composition of each electrode. Also in other embodiments, it may be desirable to have different electrostatic forces associated with each electrode.
  • the rigid member 210 is connected to the support structures 208 through torsional stabilizers 212, 214.
  • the torsional stabilizers 212, 214 are spring-like devices that attempt to maintain the rigid member 210 in a parallel relationship with the substrate 12 (Fig. 19). Responsive to external forces, however, the torsional stabilizers 212, 214 allow the rigid member 210 to tilt, as illustrated by the arrows 216, 218, 220.
  • the first electrode 202 extends diagonally in a first direction, as shown in the figure, and the second and third electrodes 204, 206 extended diagonally in a perpendicular direction to the first electrode 202.
  • the electrodes 202-206 include sufficient area to facilitate an electrostatic force for attracting the rigid member 210.
  • the electrostatic force can be controlled by other means, such as voltage level or material composition of each electrode. Also in other embodiments, it may be desirable to have different electrostatic forces associated with each electrode.
  • the rigid member 210 is connected to the support structures 208 through torsional stabilizers 222, 224.
  • the torsional stabilizers 222, 224 are similar to the ones 212, 214 of Fig. 23, except they are positioned to allow the diagonal tilting movement.
  • both embodiments 200a, 200b operate in a similar manner.
  • the rigid member 210 tilts on the torsional stabilizers 212, 214 or 222, 224, thereby tilting the mirror 22.
  • the light modulation element 200 can operate in many different states.
  • Table 12 in one configuration, each of the electrodes 202-206 can operate independently of the others. Table 12 utilizes the 0/1 voltage designations discussed above, with the 0 voltage designation representing zero volts, and the 1 voltage designation representing a supply voltage.
  • the current stat can be held at either tilt position.
  • the reset operation can be performed by a short period of high position voltage or negative voltage on electrode 204 to create a repulsive force, before returning to zero volts.
  • the light modulation element 200 can be used in an optical delivery system 250 for directing light beams 252.
  • the mirror 22 of the element 200 selectively directs the light beams 252 in a first direction 254 or a second direction 256.
  • the optical delivery system 250 is more efficient than conventional deformable mirror devices.
  • the elements, devices, and applications discussed above provide many advantages. For one, the light efficiency is very high (close to 100%). Also, there are no scanning components, although the systems 100, 150 can be used, for example, in a scanning lithography system. Another advantage is that the elements, devices, and applications above can support different wavelengths from the light source 102 with slight modification. For example, the movement distance for each mirror 22 of a light modulation element 10 can be adjusted by changing the voltages on the electrodes 14, 16, 26. Also, the applications can use either coherent or non-coherent light (time/temporal coherent or spatial coherent). Another advantage is that the light modulation device 92 does not require a separate memory.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Mechanical Light Control Or Optical Switches (AREA)

Abstract

La présente invention concerne un élément, un dispositif et un système de modulation de la lumière (10). L'élément de modulation de la lumière comprend trois électrodes (14, 16, 26), un élément rigide (20) et un miroir (22). L'élément rigide (20) est connecté entre les trois électrodes (14, 16, 26) de sorte que les première et deuxième électrodes (14, 16) se situent sur un côté et que la troisième électrode (26) se situe sur le côté opposé de l'élément rigide (20). Le miroir (22) est attaché à l'élément rigide (20) pour tourner en même temps que ce dernier. L'élément rigide (20) se déplace en réaction à une force électrostatique extérieure produite par au moins une des trois électrodes, pour que le miroir (22) soit positionné dans une position prédéterminée en réaction à l'état de l'élément rigide (20).
PCT/US2001/043560 2000-11-22 2001-11-20 Dispositif et systeme de modulation de la lumiere WO2002042825A1 (fr)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
US09/718,619 US6433917B1 (en) 2000-11-22 2000-11-22 Light modulation device and system
US09/718,619 2000-11-22
US09/728,691 US6512625B2 (en) 2000-11-22 2000-12-01 Light modulation device and system
US09/728,691 2000-12-01
US25782400P 2000-12-22 2000-12-22
US60/257,824 2000-12-22

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EP1491958A2 (fr) * 2003-06-24 2004-12-29 ASML Holding N.V. Système de projection optique pour la lithographie sans masque
US7411652B2 (en) 2003-09-22 2008-08-12 Asml Holding N.V. Lithographic apparatus and device manufacturing method
US7414701B2 (en) 2003-10-03 2008-08-19 Asml Holding N.V. Method and systems for total focus deviation adjustments on maskless lithography systems

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US7372613B2 (en) * 2004-09-27 2008-05-13 Idc, Llc Method and device for multistate interferometric light modulation
US7944599B2 (en) 2004-09-27 2011-05-17 Qualcomm Mems Technologies, Inc. Electromechanical device with optical function separated from mechanical and electrical function
JP4688131B2 (ja) * 2004-10-21 2011-05-25 株式会社リコー 光偏向装置、光偏向アレー、光学システムおよび画像投影表示装置
WO2011000689A1 (fr) * 2009-06-30 2011-01-06 Asml Holding N.V. Système de mandrin électrostatique adressable à compensation d'images
CN102253486B (zh) * 2011-08-05 2013-07-10 中国科学院光电技术研究所 偏转轴可自由变换的二维mems倾斜镜
JP6519284B2 (ja) * 2015-04-01 2019-05-29 セイコーエプソン株式会社 電気光学装置、電気光学装置の製造方法、および電子機器

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1346947A3 (fr) * 2002-03-19 2004-04-14 Japan Aviation Electronics Industry, Limited Dispositifs d'attenuation ou commutation optique contrôlés électrostatiquement
EP1491958A2 (fr) * 2003-06-24 2004-12-29 ASML Holding N.V. Système de projection optique pour la lithographie sans masque
JP2005020001A (ja) * 2003-06-24 2005-01-20 Asml Holding Nv マスクレス・リソグラフィのための投影光学系
EP1491958A3 (fr) * 2003-06-24 2006-11-02 ASML Holding N.V. Système de projection optique pour la lithographie sans masque
US7411652B2 (en) 2003-09-22 2008-08-12 Asml Holding N.V. Lithographic apparatus and device manufacturing method
US8159647B2 (en) 2003-09-22 2012-04-17 Asml Holding N.V. Lithographic apparatus and device manufacturing method
US7414701B2 (en) 2003-10-03 2008-08-19 Asml Holding N.V. Method and systems for total focus deviation adjustments on maskless lithography systems

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