U.S. Pat. No. 8,861,752 discloses a speaker array. The speaker array may include a first speaker and a second speaker. The first speaker includes a first membrane and a first shutter. The second speaker includes a second membrane and a second shutter. The first membrane may be configured to oscillate in a first directional path and at a first frequency effective to generate a first ultrasonic acoustic signal. The first shutter may be positioned above the first membrane and configured to modulate the first ultrasonic acoustic signal such that a first audio signal is generated. The second membrane may be configured to oscillate in the first directional path and at a second frequency effective to generate a second ultrasonic acoustic signal. The second shutter may be positioned above the second membrane and configured to modulate the second ultrasonic acoustic signal such that a second audio signal is generated.
Membrane 105 can be electrically coupled to controller 109. Controller 109 can be configured to apply a first signal 115 to membrane 105. In response to first signal 115, membrane 105 can oscillate along a directional path 190 effective to generate ultrasonic acoustic wave 117. Ultrasonic acoustic wave 117 may propagate along the directional path 190 from membrane 105 towards blind 103 and shutter 101.
In some examples, first alternating signal 115 may be a voltage or a current that alternates according to a first frequency. In some other examples, first alternating signal 115 may be some other variety of periodically changing signal such as a current or voltage that may be sinusoidal, pulsed, ramped, triangular, linearly changing, non-linearly changing, or some combination thereof. The oscillation frequency of membrane 105 can be substantially proportional to the frequency of first alternating signal 115. Therefore, by applying different alternating signals 115, controller 109 can control the oscillation frequency of membrane 105.
Blind 103 can be positioned above membrane 105 and below shutter 101. Blind 103 can include a first set of rectangular openings (not shown). Ultrasonic acoustic wave 117 passes through the openings of blind 103 through to shutter 101.
Shutter 101 is electrically coupled to controller 109. Controller 109 can be configured to apply a second signal 113 to shutter 101. In response to second signal 113, shutter 101 can moves along a directional path 192 between a first position and a second position. Shutter 101 includes a second set of openings (not shown). The relationship and orientation of the first set of openings relative to the second set of openings will be further described below.
Second speaker device 220 can include a second shutter 221 and a second membrane 223. Second shutter 221 and second membrane 223 are both electrically coupled to controller 230. Controller 230 can be configured to apply a third signal to second shutter 221 and a fourth signal to second membrane 223. As set forth above, the moving frequency of second shutter 221 and the oscillation frequency of second membrane 223 are associated with the third signal and the fourth signal, respectively. A second audio signal can be generated based on the movement of the second shutter 221 and the oscillating membrane 223.
When the moving frequencies of first shutter 211 and second shutter 221, and the oscillation frequencies of first membrane 213 and second membrane 223 are substantially the same, the first audio signal can be generated by first speaker device 210 and the second audio signal can be generated by second speaker device 220 have substantially the same frequency. When the moving frequencies of first shutter 211 and second shutter 221 are different, or the oscillation frequencies of first membrane 213 and second membrane 223 are different, the first audio signal generated by first speaker 210 and the second audio signal generated by second speaker 220 have substantially different frequencies. Generating different audio signals from various elements in the speaker array can be used for generating psychoacoustic effects creating the illusion of novel sound location or unique temporal effects in the acoustic signal.
There is a growing need to provide efficient manufacturing process for manufacturing such a speaker.
According to an embodiment of the invention there may be provided a MEMS device that may include a substrate, support structures and functional elements; wherein the functional elements may be included in a plurality of functional layers, the plurality of functional layers may be spaced apart from each other; wherein the support structures may be conductive and may be configured to provide structural support to the plurality of functional layers; wherein each functional element may be electrically coupled to at least one of the support structures; and wherein the support structures may be spaced apart from each other.
A given support structure may include first portions that may be included within the plurality of functional layers and second portions which may be positioned between the plurality of functional layers.
The first portions and the second portions may be vertically aligned.
The first portions and the second portions may be vertically misaligned.
The support structures may include a conductive envelope and one or more core segments that may be at least partially insulating.
The support structures may include one or more core segments that may be surrounded by other segments; wherein the other segments may include a conductive envelope; wherein for a given etch process the one or more core segments exhibit an etch rate that exceeds an etch rate of the other segments.
The one or more core segments may be made of a material selected out of Tetraethyl orthosilicate, Silicon Oxide, and undoped Silica glass (USG).
A number of functional layers of the plurality of functional layers may exceed three.
The MEMS functional elements may include a membrane, a blind and a shutter.
The membrane, the blind and the shutter belong to different functional layers of the plurality of functional layers.
The support structures may be arranged in groups.
A given group of support structures may be electrically coupled to a given MEMS functional element; and wherein the given group of support structures surrounds the given MEMS functional element.
At least two groups of support structures share at least one support structure.
At least two adjacent groups of support structures do not share any support structure.
All support structures of a given group of support structures have a same size and shape.
Two or more support structures of a given group of support structures differ from each other by shape.
Two or more support structures of a given group of support structures differ from each other by size.
There may be at least three support structures per group.
The support structures may be shaped as pillars.
The MEMS device further may include one or more perforated dielectric functional layers.
A first functional element may belong to a first functional layer and wherein a second functional element may belong to a second functional layer.
There may be an air gap between the support structures.
A first functional element that belongs to a first functional layer may be electrically coupled to a first set of support structures; wherein a second functional element that belongs to a second functional layer may be coupled to a second set of support structures; wherein the first set of support structures differs from the second set of support structures.
Some functional elements that belong to some functional layers may be electrically coupled to different sets of support structures.
A certain functional layer may include multiple functional elements.
All of the multiple functional elements of the certain functional layer are substantially identical to each other.
At least some functional elements of the multiple functional elements of the certain functional layer differ from each other.
All of the multiple functional elements of the certain functional layer may be electrically coupled to each other.
Some of the multiple functional elements of the certain functional layer may be not electrically coupled to each other.
A functional element that belongs to a certain functional layer may be electrically coupled to a set of the support structures; wherein there may be an air gap between the functional element and support structures that may be not included in the set of support structures.
Each functional layer of at least two functional layers may include multiple functional elements.
According to an embodiment of the invention there may be provided a method for manufacturing a micro-electromechanical system (MEMS) device. The method may include performing a plurality of manufacturing iterations to provide an alternating sequence of functional layers and intermediate layers; wherein the functional layers comprise functional elements and portions of support structures; wherein each functional element is electrically coupled to at least one of the portions of the support structure; wherein the intermediate layers comprise other portions of the support structures and a filling material; and removing the filling material to provide functional layers that are spaced apart from each other and are supported by the support structures; wherein the support structures are conductive and are spaced apart from each other. The filling material may include, for example, Silicon Oxide.
At least one manufacturing iteration may include surrounding a core made of a filling material with a material that withstands the removing of the filling material.
According to an embodiment of the invention there may be provided a method for manufacturing a micro-electromechanical system (MEMS) device. The method may include generating multiple sacrificial layer patterns and multiple conductive layer patterns by repeating the steps of depositing a sacrificial layer; patterning the sacrificial layer to provide a sacrificial layer pattern; depositing a conductive layer; patterning the conductive layer thereby forming a conductive layer pattern. The method may proceed by depositing a top sacrificial layer; patterning the top sacrificial layer to provide a top sacrificial layer pattern; depositing a top conductive layer; depositing a metal layer; patterning the metal layer to provide a metal layer pattern; patterning the top conductive layer thereby forming the top conductive layer pattern; and removing, by applying an etch process, each sacrificial layer pattern that is exposed to the etch process thereby exposing support structures and functional elements that are formed by the multiple conductive layer patterns.
The generating of the multiple sacrificial layer patterns and of the multiple conductive layer patterns may be preceded by depositing a passivation layer on a substrate; and patterning the passivation layer to provide a passivation layer pattern.
The multiple conductive layer patterns may define the functional elements and/or define edges of the support structures.
The functional elements may be included in a plurality of functional layers, the plurality of functional layers may be spaced apart from each other; wherein the support structures may be conductive and may be configured to provide structural support to the plurality of functional layers; wherein each functional element is electrically coupled to at least one of the support structures; and wherein the support structures may be spaced apart from each other.
The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.
The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.
The term “conductive” means electrically conductive.
According to an embodiment of the invention there is provided a speaker or an array of speakers that includes multiple layers. For example the speaker may include a first layer followed by a first intermediate layer, followed by a second layer, followed by a second intermediate layer that is followed by a third layer. These layers are manufactured by a lithographic process using masks. In any of the following figures mask dark elements may represents areas that are not etched or etched, per specific mask.
According to an embodiment of the invention there are provided support structure that are electrically conductive. A support structure is deemed to be conductive even when it includes electrically insulating elements and electrically conductive elements. For example—a conductive support structure may include a conductive envelope that may surround one or more insulating elements.
Any reference to a support structure should be regarded as a reference to an electrically conductive support structure.
Set 13 includes four support structures denotes 11 (first sub-set of support structures), four support structures denoted 12 (second sub-set of support structures), and four support structures denoted 13 (third sub-set of support structures).
Support structures 11 differ by shape from support structures 12 and 13. Support structures 12 differ by orientation from support structures 13.
A set of support structures may have support structures of any shape size and orientation.
All the support structures of the set 31 are spaced apart from each other.
The sets of the array are arranged in an orderly space-periodic form. It should be noted that the support structure of adjacent cells are reused for these cells for better spacial efficiency.
Shutter 53 contacts a third sub-set of support structures (support structures 13) and is spaced apart (by an air gap) from support structures 11 and 12.
Each one of the first, second and third layers 61, 62 and 63 may be formed by using one or more masks. Intermediate layers may be manufactured below and/or above each one of the first, second and third layers 61, 62 and 63. These intermediate layers may be partially etched and provide at least some of the support structure.
Mask 82′ may be used for depositing a layer to provide acoustic isolation between the membrane and the membrane vicinity (positioned below the second intermediate layer) and the shutter and the vicinity of the shutter
Top layer 86 includes bond pads 101, 102 and 103 and connections 111, 112 and 113 that are connected between the supporting structures for lower membrane (first layer), shutter (of the third layer) and the blind (second layer) respectively and the bond pads 101, 102 and 103, according to an embodiment of the invention.
In MEMS processing, free standing membranes are formed by etching a sacrificial layer from below and above the membrane. Examples of such devices include, CMUT, Gyros, accelerometers, mirrors and others. The etch is done with a HF vapor which etches isotropically. Hence any removal of material from under the membrane also removes material from the sides of the membrane.
The current application is applicable to any MEMS device, but for simplicity of explanation it is described in detail for MEMS speakers.
The fill factor (or distance between membranes) is limited because of the sideways etch of the 1st, 2nd and 3rd sacrificial layers. Hence, if the etch is not limited by some means, this distance is at least twice the maximum horizontal etch under the membrane.
To increase sound volume generation per given silicon area, or to increase silicon utilization and reduce cost there, is a need to increase the fill factor.
According to an embodiment of the invention there is provided a multi layered MEMS device that includes a top surface with electrical pads deposited on top surface (for example top layer of
Method 1400 may start by step 1410 of depositing a passivation layer on a substrate; and patterning the passivation layer to provide a passivation layer pattern.
Step 1410 may be followed by step 1420 of generating multiple sacrificial layer patterns and multiple conductive layer patterns by repeating (for example N−1 times) the steps of depositing a sacrificial layer, patterning the sacrificial layer to provide a sacrificial layer pattern, depositing a conductive layer and patterning the conductive layer thereby forming a conductive layer pattern.
Step 1420 may include performing multiple manufacturing iterations. Each manufacturing iterations includes depositing a sacrificial layer, patterning the sacrificial layer to provide a sacrificial layer pattern, depositing a conductive layer and patterning the conductive layer thereby forming a conductive layer pattern.
The sacrificial layer patterned during a manufacturing iteration is deposited on top of the conductive layer pattern formed during the previous manufacturing iteration.
The patterning of each sacrificial layer of step 1420 may include creating a photoresist layer pattern; developing the photoresist pattern; etching the sacrificial layer to form the sacrificial layer pattern; wherein the etching comprises removing completely all sacrificial layers parts not covered by the photoresist pattern.
Step 1420 may be followed by step 1430 of depositing a top (N'th) sacrificial layer; patterning the top sacrificial layer to provide a top sacrificial layer pattern; depositing a top (N'th) conductive layer. Depositing a metal layer. Patterning the metal layer to provide a metal layer pattern. Patterning the top conductive layer thereby forming the top conductive layer pattern.
Step 1430 may be followed by step 1440 of removing, by applying an etch process, each sacrificial layer pattern that is exposed to the etch process thereby exposing support structures and functional elements that are formed by the multiple conductive layer patterns.
The multiple conductive layer patterns may define the functional elements and/or define edges of the support structures.
Method 1400 may be used to manufacture a MEMS device that includes a substrate, support structures and functional elements; wherein the functional elements may be included in a plurality of functional layers, the plurality of functional layers may be spaced apart from each other; wherein the support structures may be conductive and may be configured to provide structural support to the plurality of functional layers; wherein each functional element may be electrically coupled to at least one of the support structures; and wherein the support structures may be spaced apart from each other.
Method 1500 may start by step 1510 of performing a plurality of manufacturing iterations to provide an alternating sequence of functional layers and intermediate layers. The functional layers comprise functional elements and portions of support structures; wherein each functional element is electrically coupled to at least one of the portions of the support structure; wherein the intermediate layers comprise other portions of the support structures and a filling material.
Step 1510 may be followed by step 1520 of removing the filling material to provide functional layers that are spaced apart from each other and are supported by the support structures. The support structures are conductive and are spaced apart from each other. The filling material may include, for example, Silicon Oxide.
Non-limiting example of step 1510 include step 1420 of method 1400.
At least one manufacturing iteration may include surrounding a core made of a filling material with a material that withstands the removing of the filling material.
Any reference in the specification to a system should be applied mutatis mutandis to a method that may be executed by the system.
In the foregoing specification, the invention has been described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications and changes may be made therein without departing from the broader spirit and scope of the invention as set forth in the appended claims.
Those skilled in the art will recognize that the boundaries between MEMS cells or functional elements blocks are merely illustrative and that alternative embodiments may merge MEMS cells or functional elements or impose an alternate decomposition of functionality upon various MEMS cells or functional elements. Thus, it is to be understood that the architectures depicted herein are merely exemplary, and that in fact many other architectures may be implemented which achieve the same functionality. Any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality may be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected,” or “operably coupled,” to each other to achieve the desired functionality.
Furthermore, those skilled in the art will recognize that boundaries between the above described operations merely illustrative. The multiple operations may be combined into a single operation, a single operation may be distributed in additional operations and operations may be executed at least partially overlapping in time. Moreover, alternative embodiments may include multiple instances of a particular operation, and the order of operations may be altered in various other embodiments.
Also for example, in one embodiment, the illustrated examples may be implemented as circuitry located on a single MEMS device or within multiple MEMS devices. Alternatively, the examples may be implemented as any number of separate MEMS devices or separate MEMS devices interconnected with each other in a suitable manner.
However, other modifications, variations and alternatives are also possible. The specifications and drawings are, accordingly, to be regarded in an illustrative rather than in a restrictive sense.
In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word ‘comprising’ does not exclude the presence of other elements or steps then those listed in a claim. Furthermore, the terms “a” or “an,” as used herein, are defined as one or more than one. Also, the use of introductory phrases such as “at least one” and “one or more” in the claims should not be construed to imply that the introduction of another claim element by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim element to inventions containing only one such element, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an.” The same holds true for the use of definite articles. Unless stated otherwise, terms such as “first” and “second” are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage.
While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
This application claims priority from U.S. Provisional Patent Application Ser. No. 62/134,076 filing date Mar. 17, 2015 which is being incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
62134076 | Mar 2015 | US |