Patent Publication Number: US-2017355591-A1

Title: Microelectromechanical device and a method of manufacturing a microelectromechanical device

Description:
TECHNICAL FIELD 
     Various embodiments relate generally to a microelectromechanical component and a method of manufacturing a microelectromechanical component. 
     BACKGROUND 
     Microelectromechanical systems (MEMS) may include a diaphragm and two electrodes, e.g., a dual backplate microphone (DBP microphone). MEMS may also be known as micromachines or micro systems technology. Such systems may include a corrugated diaphragm. A diaphragm that is corrugated may have an increased flexibility (or sensitivity or compliance), that increases a functional bandwidth of the diaphragm in, for example, a MEMS DBP microphone. 
     A DBP microphone may, for example, include an electrode on either side of the diaphragm. This arrangement may present difficulties in the manufacture of such a device due to factors such as device or material temperature budget or device scale. Therefore, a microelectromechanical device including a corrugated diaphragm and at least one electrode, as well as, a method of manufacturing such a microelectromechanical device, may be advantageous. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, like reference characters generally refer to the same parts throughout the different views, e.g., layer  210 , layer  310 , layer  410 , layer  510 ). The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the invention are described with reference to the following drawings, in which: 
         FIG. 1A-1B  show rounding of photoresist. 
         FIG. 1C  shows a method of manufacturing a microelectromechanical component. 
         FIG. 2A-2D  show, in a partial view of a cross-section, a method of manufacturing a microelectromechanical component and the components at various stages of manufacture according to an embodiment of the disclosure. 
         FIG. 3A-3D  show, in cross-section, a method of manufacturing a microelectromechanical component and the components at various stages of manufacture according to an embodiment of the disclosure. 
         FIG. 3E-3F  show, in cross-section and projection, a method of manufacturing a microelectromechanical component and the components at various stages of manufacture according to an embodiment of the disclosure. 
         FIG. 4A-4U  show, in cross-section, a method of manufacturing a microelectromechanical component and the components at various stages of manufacture according to an embodiment of the disclosure. 
         FIG. 5A-5E  show, in cross-section, a method of manufacturing a microelectromechanical component and the components at various stages of manufacture according to an embodiment of the disclosure. 
         FIG. 5F  shows a method of manufacturing a microelectromechanical component. 
     
    
    
     DESCRIPTION 
     The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the invention may be practiced. In the following figures, similar or the same elements may have similar or the same reference numerals (e.g., layer  210 , layer  310 , layer  410 , layer  510 ). A description of the element may, in the interests of brevity and repetition prevention, therefore, be omitted in subsequent descriptions. 
     The word “exemplary” is used herein to mean “serving as an example, instance, or illustration”. Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs. 
     The word “over” used with regards to a deposited material formed “over” a side or surface, may be used herein to mean that the deposited material may be formed “directly on”, e.g., in direct contact with, the implied side or surface. The word “over” used with regards to a deposited material formed “over” a side or surface, may be used herein to mean that the deposited material may be formed “indirectly on” the implied side or surface with one or more additional layers being arranged between the implied side or surface and the deposited material. 
     As used herein, a “circuit” may be understood as any kind of logic (analog or digital) implementing entity, which may be special purpose circuitry or a processor executing software stored in a memory, firmware, hardware, or any combination thereof. Furthermore, a “circuit” may be a hard-wired logic circuit or a programmable logic circuit such as a programmable processor, for example a microprocessor (for example a Complex Instruction Set Computer (CISC) processor or a Reduced Instruction Set Computer (RISC) processor). A “circuit” may also be a processor executing software, for example, any kind of computer program, for example a computer program using a virtual machine code such as, for example, Java. Any other kind of implementation of the respective functions which will be described in more detail below may also be understood as a “circuit”. It is understood that any two (or more) of the described circuits may be combined into a single circuit with substantially equivalent functionality, and, conversely, that any single described circuit may be distributed into two (or more) separate circuits with substantially equivalent functionality. In particular with respect to the use of “circuitry” in the Claims included herein, the use of “circuit” may be understood as collectively referring to two or more circuits. 
     The term “forming” may refer to disposing, arranging, structuring, or depositing. A method for forming, e.g., a layer, a material, or a region, etc., may include various deposition methods which, inter alia, may include: chemical vapor deposition, physical vapor deposition (e.g., for dielectric materials), electrodeposition (which may also be referred to as electroplating, e.g., for metals or metal alloys), or spin coating (e.g., for fluid materials). Generally, a vapor deposition may be performed by sputtering, laser ablation, cathodic arc vaporization, or thermal evaporation. A method for forming metals may include metal plating, e.g., electroplating or chemical plating. 
     The term “forming” may also include a chemical reaction or fabrication of a chemical composition, where, for example, at least a portion of the layer, the material, or the region is formed by a transformation of one set of chemical substances into the chemical composition. “Forming” may, for example, include: changing the positions of electrons by breaking or forming chemical bonds between atoms of the set of chemical substances. The term “forming” may further include oxidation and reduction, complexation, precipitation, acid-base reaction, solid-state reaction, substitution, doping, addition and elimination, diffusion, or a photochemical reaction. “Forming” may, for example, change the chemical and physical properties of the set of chemical substances which chemically compose a portion of the layer, material, or region. Exemplary chemical properties or physical properties may include electrical conductivity, phase composition, or optical properties, etc. “Forming” may, e.g., include the application of a chemical reagent to an initial compound to change the chemical and physical properties of the initial compound. 
     The term “structuring” may refer to modifying the form of a structure (e.g., modifying the structure to achieve a desired shape or a desired pattern). To structure, e.g., a material, a portion of the material may be removed, e.g., via etching. To remove material from, for example a layer, material, or region, a mask (that provides a pattern) may be used, i.e., the mask provides a pattern for removing material (e.g., etching a structure to remove material of the structure) according to the pattern of the mask. Illustratively, the mask may prevent regions (which may be intended to remain) from being removed (e.g., by etching). Alternatively or additionally, to structure the layer, the material or the region of material may be disposed using a mask (the mask providing a pattern). The mask may provide a pattern for forming (e.g., disposing) material in accordance with the pattern of the mask. 
     In general, removing material may include a process such as etching of the material. The term “etching” may include various etching procedures, e.g., chemical etching (including, for example, wet etching or dry etching), physical etching, plasma etching, ion etching, etc. In etching a layer, a material, or a region, an etchant may be applied to the layer, the material, or the region. For example, the etchant may react with the layer, the material, or the region, forming a substance (or chemical compound) which may be easily removed, e.g., a volatile substance. Alternatively or additionally, the etchant may, for example, vaporize the layer, the material, or the region. 
     A mask may be a temporary mask, i.e., it may be removed after etching (e.g., the mask may be formed from a resin or a metal or another material such as a hard mask material such as silicon oxide, silicon nitride, or carbon, etc.) or the mask may be a permanent mask (e.g., a mask-blade), which may be used several times. A temporary mask may be formed, e.g., using a photomask. 
     According to various embodiments, a microelectromechanical device may be formed as part of, or may include, a semiconductor chip. For example, the semiconductor chip may include the microelectromechanical component (which may also be referred to as a microelectromechanical system). In other words, the microelectromechanical component may be implemented into (e.g., may be part of) a semiconductor chip, e.g., monolithically integrated. The semiconductor chip (which may also be referred to as a chip, die, or microchip) may be processed in semiconductor technologies, on a wafer, or in a wafer (or, e.g., a substrate or a carrier). The semiconductor chip may include one or more microelectromechanical systems (MEMS), which are formed during semiconductor technology processing or fabrication. The semiconductor carrier may be part of the semiconductor chip, e.g., the semiconductor carrier may be part of, or may form, the semiconductor body of the chip. Optionally, the microelectromechanical component may be part of, or may be electrically coupled to, an integrated circuit on the chip. 
     According to various embodiments, a semiconductor carrier (e.g., of a microelectromechanical device, e.g., the semiconductor carrier of a semiconductor chip) may be singulated from a wafer by removing material from a kerf region of the wafer (also referred to as dicing or cutting the wafer). For example, removing material from the kerf region of the wafer may be processed by scribing and breaking, cleavage, blade dicing, or mechanical sawing (e.g., using a dicing saw). In other words, the semiconductor carrier may be singulated by a wafer dicing process. After the wafer dicing process, the semiconductor carrier (or the finished microelectromechanical device) may be electrically contacted and encapsulated, e.g., by mold materials, into a chip carrier (which may also be referred to as a chip housing) which may then be suitable for use in electronic devices, such as gauges. For example, the semiconductor chip may be bonded to a chip carrier by wires. Furthermore, the semiconductor chip (which may be bonded to a chip carrier) may be mounted (e.g., soldered) onto a printed circuit board. 
     According to various embodiments, a semiconductor carrier (e.g., of a microelectromechanical device or the semiconductor carrier of a semiconductor chip) may include or may be made of (in other words, formed from) semiconductor materials of various types, including a group IV semiconductor (e.g., silicon or germanium), a compound semiconductor, e.g., a group III-V compound semiconductor (e.g., gallium arsenide), or other types, including group III semiconductors, group V semiconductors, or polymers, for example. In an embodiment, the semiconductor carrier may be made of silicon (doped or undoped). In an alternative embodiment, the semiconductor carrier may be a silicon on insulator (SOI) wafer. As an alternative, any other suitable semiconductor material may be used for the semiconductor carrier, for example, semiconductor compound material such as gallium phosphide (GaP), indium phosphide (InP), or any suitable ternary semiconductor compound material, such as indium gallium arsenide (InGaAs), or quaternary semiconductor compound material, such as aluminium gallium indium phosphide (AlInGaP). 
     According to various embodiments, a semiconductor carrier (e.g., of a microelectromechanical device or the semiconductor carrier of a semiconductor chip) may be covered with a passivation layer for protecting the semiconductor carrier from environmental influence, e.g., oxidation. The passivation layer may include a metal oxide, an oxide of the semiconductor carrier (which may also be referred to as a substrate or semiconductor body), e.g., silicon oxide, a nitride, e.g., silicon nitride, a polymer, e.g., benzocyclobutene (BCB) or polyimide (PI), a resin, a resist, or a dielectric material. 
     According to various embodiments, an electrically conductive material may include or may be formed from: a metal, a metal alloy, an intermetallic compound, a silicide (e.g., titanium silicide, molybdenum silicide, tantalum silicide, or tungsten silicide), a conductive polymer, a polycrystalline semiconductor, or a highly doped semiconductor, e.g., polycrystalline silicon (which may also be referred to as polysilicon), or a highly doped silicon. An electrically conductive material may be understood as material with moderate electrical conductivity, e.g., with an electrical conductivity (measured at room temperature and constant electric field direction) greater than about 10 S/m, e.g., greater than about 10 2  S/m, or with high electrical conductivity, e.g., greater than about 10 4  S/m, e.g., greater than about 10 6  S/m. 
     According to various embodiments, a metal may include or may be formed from one element of the following group of elements: aluminum, copper, nickel, magnesium, chromium, iron, zinc, tin, gold, silver, iridium, platinum, or titanium. Alternatively or additionally, a metal may include or may be formed from a metal alloy including one element or more than one element. For example, a metal alloy may include an intermetallic compound, e.g., an intermetallic compound of gold and aluminum, an intermetallic compound of copper and aluminum, an intermetallic compound of copper and zinc (brass) or an intermetallic compound of copper and tin (bronze). 
     According to various embodiments, an electrically insulating material, e.g., a dielectric material, may be understood as material with poor electrical conductivity, e.g., with an electrical conductivity (measured at room temperature and constant electric field direction) less than about 10 −2  S/m, e.g., less than about 10 −5  S/m, or, e.g., less than about 10 −7  S/m. 
     According to various embodiments, an insulating material may include a semiconductor oxide, a metal oxide, a ceramic, a semiconductor nitride, a metal nitride, a semiconductor carbide, a metal carbide, a glass, e.g., fluorosilicate glass (FSG), a dielectric polymer, a silicate, e.g., hafnium silicate or zirconium silicate, a transition metal oxide, e.g., hafnium dioxide or zirconium dioxide, an oxynitride, e.g., silicon oxynitride, or any other type of dielectric material. An insulating material may withstand an electric field without breaking down (in other words without experiencing failure of its insulating properties, e.g., without substantially changing its electrical conductivity). 
     According to various embodiments, a microelectromechanical component may be configured to at least one of: provide a force to actuate a diaphragm in response to an electrical signal transmitted to the electrically-conductive component and provide an electrical signal in response to an actuation of the diaphragm. In general, a microelectromechanical component may be configured to transfer mechanical energy into electrical energy and/or electrical energy into mechanical energy. In other words, a microelectromechanical component may function as a transducer that is configured to convert mechanical energy into electrical energy or vice versa. A microelectromechanical component may have a size in the range from about a few micrometers (μm) to about a few millimeters (mm), e.g., in the range from about a 10 μm to about 5 mm, e.g., in the range from about a 100 μm to about 2 mm, e.g., about 1 mm, or, alternatively, smaller than about 1 mm, e.g., smaller than 500 μm, e.g., smaller than 100 μm. A microelectromechanical component according to various embodiments may be processed in semiconductor technology. 
     A microelectromechanical component according to various embodiments may be used as a sensor (e.g., a micro-sensor) for sensing a mechanical signal and to generate an electrical signal which represents the mechanical signal. Alternatively, a microelectromechanical component may be used as an actuator for generating a mechanical signal based on the electrical signal. For example, the microelectromechanical component may be used as microphone or as a speaker (loudspeaker). 
     The microelectromechanical component may include a diaphragm. The diaphragm may be configured to actuate in response to a force. The force may be provided externally from the microelectromechanical component, i.e., the force may not originate from the microelectromechanical device. The force may be a mechanical interaction, i.e., a pressure-gradient, e.g., a mechanical wave (including acoustic waves or sound waves), pressure, such as gauge pressure. Additionally or alternatively, the force may be an electric field interaction, i.e., a Coulomb force or an electrostatic force, or may be a magnetic field interaction, e.g., magnetic force, such as Lorentz force, etc. An electrically-conductive component, e.g., an electrode or a sensor, may provide an electrical signal in response to the actuation of the diaphragm. The electrical signal may represent the force on the diaphragm or the actuation of the diaphragm (e.g., or the electrical signal may be proportional to the force). 
     Additionally or alternatively, the force to actuate the diaphragm may be provided by the microelectromechanical component, i.e., the force may originate from an element of the microelectromechanical component. For example, the force may be provided by an electrically-conductive component, e.g., an electrode that is part of the microelectromechanical component. The electrically-conductive component may provide a force to actuate the diaphragm in response to an electrical signal transmitted to the electrically-conductive component. The electrical signal may be transmitted by a circuit, e.g., a controller or a processor. The electrically-conductive component may exert a force on the diaphragm by an electric field interaction, a magnetic field interaction, or a combination thereof. 
       FIG. 1A-1B  show rounding of photoresist, which may be used to manufacture a microelectromechanical component. A microelectromechanical component, such as a DBP microphone, may include two electrodes on either side of a membrane, or diaphragm. To manufacture such a component, processes such as a local oxidation of silicon (LOCOS) process may not be available, e.g., due to temperature budget constraints of the component and materials, to form a corrugated diaphragm. An exemplary process to achieve a corrugated diaphragm for a microelectromechanical component, for example, a component including two electrodes either side of the diaphragm, may include resist reflow techniques which may round, or smooth out, or form an undulating profile, in a polymer, e.g., photoresist, by heating. 
       FIG. 1A  shows examples  100  of rounded polymers via a reflow technique, e.g., thermal reflow. The polymers may be or include a lacquer, resin, (photo)resist, etc. The polymers may be heated to at least the glass transition temperature of the polymer, which may be, for example, between 120° C. to 170° C.; for example, a diazonaphthoquinone-photoresist may have a glass transition temperature between 120° C. and 135° C., and may be heated to at least this temperature. The polymers may also be heated for a certain period of time, for example, a polymer may be heated to 140° C. for 2 minutes, e.g., a photoresist for lithographic processes. Example 110 shows an exemplary heating of a photoresist to 150° C. for about 1 minute to about 60 minutes. Example 120 shows an exemplary heating of a photoresist to 160° C. for 1 minute to about 60 minutes, and example  130  shows an exemplary heating of a photoresist to 170° C. for about 1 minute to about 60 minutes. As can be seen, different heating times and temperatures may cause the form of the photoresist to change, e.g., edges of the photoresist may be rounded. 
     Polymers may have a glass transition temperature (T g ) (as defined by viscosity, thermal expansion, heat capacity, shear modulus, or other properties, etc.). Increasing a temperature applied to a polymer increases a temperature of the polymer (or portions of the polymer, e.g., a thermal gradient in a structure including polymer), which may adjust, e.g., reduce, the viscosity of the polymer, thus causing the polymer to reflow and form a rounded surface, i.e., a profile or contour, of the polymer due to surface tension. The lateral reflow of the polymer may depend on a contact angle between the polymer and a solid surface (e.g., wettability of the solid surface). 
       FIG. 1B  is a profile view  150  of photoresist structure  155  after heating, e.g., thermal reflow. Depending on temperature and time, a photoresist structure  155  may be formed with a designated width  154 , e.g., in a range from about 1 μm to about 50 μm, e.g., about 17 μm, and height, e.g., in a range from about 1 μm to about 10 μm, e.g., about 4 μm. 
     Such thermal reflow techniques may be used to form a corrugated diaphragm, as discussed below. Corrugations, or undulations, in a diaphragm may increase the compliance of the diaphragm. Increased compliance may be used to form a diaphragm with a higher sensitivity. Corrugations with smooth (e.g., rounded, smoothed out, or undulating) transitions may avoid stress concentrations. 
       FIG. 1C  depicts a method of manufacturing a microelectromechanical component  101 , the method including: forming a mask over a layer, the mask comprising a structured surface  150 ; heating a region of the mask comprising the structured surface above a glass transition temperature of the mask to smooth out edges of the structured surface to form a corrugated surface  160 ; etching the layer covered by the mask, the etching removing the mask to carry over the corrugated surface of the mask into the layer and to form a corrugated surface of the layer  170 ; forming a diaphragm over the layer to form a corrugated region of the diaphragm configured to actuate  180 ; and forming an electrically-conductive component configured to at least one of: provide a force to actuate the diaphragm in response to an electrical signal transmitted to the electrically-conductive component and provide an electrical signal in response to an actuation of the diaphragm  190 . Method  101  will be described in more detail in the following description of figures. 
       FIG. 2A-2D  show, in a partial view of a cross-section, a method of manufacturing a microelectromechanical component and the components at various stages of manufacture according to an embodiment of the disclosure. 
       FIG. 2A  shows the process  200 A of forming a mask  230  over a layer  210 , where the mask includes a structured (e.g., exposed) surface  240 .  FIG. 2A  also depicts electrically-conductive component  220 , e.g., an electrode. 
     As discussed above, mask  230  may be a polymer, e.g., a lacquer, a resin, a resist, or a photoresist. The mask  230  may be formed on layer  210 , e.g., deposited. Layer  210  may be a substrate (a passive substrate material); e.g., formed of silicon, such as monocrystalline silicon, polycrystalline silicon, microcrystalline silicon, or nanocrystalline silicon; an oxide layer, such as an oxide of silicon, e.g., silicon dioxides or tetraethyl orthosilicate (TEOS). Electrically-conductive component  220 , e.g., an electrode, may be formed in layer  210 , e.g., electrically-conductive component  220  may be formed before layer  210  is deposited over the electrically-conductive component  220  or, alternatively, electrically-conductive component  220  may be formed in the layer  210 , i.e., layer  210  may exemplarily be oriented in another manner and electrically-conductive component  220  may be formed over layer  210 . Layer  210  may then be oriented in another manner for further processing. Alternatively, layer  210  may not require any reorientation to process multiple sides of the layer  210 , thus mask  230  may be formed over layer  210  and electrically-conductive component  220  may be formed on the opposite side of layer  210  from mask  230  without any need to reorient layer  210 . 
     Mask  230  may be altered (structured) to form structured surface  240  of the mask  230 . Structuring the surface of mask  230  may vary the surface of the mask  230 , e.g., changing a profile of the mask  230 , patterning the mask  230 , forming specific shapes in the mask  230 . Structured surface  240  may have angular edges  241 , e.g., due to an etching process. An angular edge may be an intersection of two surfaces, for example, a line formed from the intersection of two surfaces, such as an edge of a cube. A profile of structured surface  240  may, for example, be rectangular, trapezoidal, or be composed of a step-like profile. The overall shape of structured surface  240  may be a circle (or ring). Structured surface  240  of  FIG. 2A  may represent a cross-section of a portion of a ring. 
     Structured surface  240  may include any surface that has been altered into a desired or specified form from depositing or forming of mask  230  on layer  210 . Structured surface  240  may include, for example, a protrusion, a recess, steps, or a geometric shape. 
       FIG. 2B  shows process  200 B of heating a region of the mask  230  including the structured surface  240  above a glass transition temperature of the mask  230  to smooth out edges  241  of the structured surface  240  to form a corrugated surface  245 . Arrow  244  represents the transfer of thermal energy, i.e., heating. 
     A region of the mask  230  including the structured surface  240  may be locally heated or the entire arrangement depicted in process  200 B may be heated. For example, structured surface  240  may be locally heated with focused thermal energy, e.g., laser radiation for locally induced heating, i.e., structured surface  240  may be selectively exposed to a heat source. Alternatively or additionally, layer  210  including electrically-conductive component  220  and mask  230  (and structured surface  240 ) may be simultaneously exposed to a heat source (e.g., a heat transfer). 
     Mask  230  may have a glass transition temperature and in process  200 B, may be heated above the glass transition temperature of mask  230 , i.e., of the material (or, e.g., materials) forming mask  230 , or heated substantially to the glass transition temperature of mask  230 . At the glass transition temperature, mask  230 , including structured surface  240 , may reflow, i.e., the viscosity of the material forming mask  230  may change, i.e., may be reduced thus causing mask  230  or structured surface  240  to flow. The final profile or shape of the structured surface  240  may be defined by a variety of factors, such as the material of the mask  230 ; the viscosity of the material forming the mask  230 ; the temperature of the structured surface  240  (mask  230 ); the temperature of the heat source (or the medium that is transferring thermal energy to the structured surface  240 ); the amount of time the structured surface  240  is exposed to the heat source; external forces acting on the structured surface  240 , e.g., gravity; as well as internal forces of the structured surface  240 , e.g., cohesive forces related to surface tension. The time and temperature the structured surface  240  is exposed to may each be predefined. 
     Based on at least the above-identified parameters, structured surface  240  may assume, e.g., transform, into another shape or profile. The resultant shape may have a reduced surface area and may smooth out, or round, any edges  241  of the structured surface  240 . Structured surface  240  may form (e.g., may be transformed) into corrugated surface  245  of mask  230 . Corrugated surface  245  may be a smoothed out, or rounded, version of structured surface  240  (e.g., a rounded variant or rendition of structured surface  240 ). Corrugated surface  245  may be ring-like in overall shape ( FIG. 2B  only depicts a portion of mask  230  and corrugated surface  245 ), having a rounded profile or cross-section. 
       FIG. 2C  shows process  200 C of etching the layer  210  covered by the mask  230 , the etching removing the mask  230  to carry over the corrugated surface  245  of the mask  230  into the layer  210  and to form a corrugated surface  215  of the layer  210 . 
     Etching layer  210  may partially or completely remove mask  230 . Etching layer  210  may further carry over (i.e., reproduce or form in the layer) corrugated surface  245  of the mask  230 , i.e., a surface of layer  210 , after etching, may have a corrugated surface  215  where the mask  230  was etched. During process  200 C a portion of layer  210  may be removed, for example, a sacrificial oxide may be removed from layer  210 , i.e., the overall thickness of layer  210  may be reduced, while forming corrugated surface  215  in layer  210 . Mask  230  and structured surface  240  thus act as a guide, affecting, or dictating in certain areas, the etching of the layer  210 . 
     Etching the layer  210  may involve a selective etching process, i.e., the etchant may be selected to etch different materials at different rates, or may not etch a particular material. Additionally or alternatively, a dry-etching process may be used. Additionally or alternatively, the mask  230  and layer  210  may be etched at substantially similar rates, for example, the etch rate of layer  210  and mask  230  may be substantially 1:1. 
       FIG. 2D  shows process  200 D of forming a diaphragm  250  over the layer  210  to form a corrugated region  255  of the diaphragm  250 , which is configured to actuate. 
     Diaphragm  250  may be formed over layer  210 , including structured surface  215 , i.e., diaphragm  250  may conform to the corrugated surface  215  of layer  210 , e.g., diaphragm  250  may have a topography that corresponds to the topography of corrugated surface  215  and layer  210 . Accordingly, diaphragm  250  may have a corrugated region  255  (a corrugated region in that the diaphragm  250  is three-dimensional and thus includes the corrugated, or undulating, region of the diaphragm  250 ). 
     The corrugated region  255  of the diaphragm  250  may have a round, wave-like profile, e.g., undulating or having smooth transitions. The corrugated region  255  may have an overall ring-like shape and may only be partially depicted in  FIG. 2D , i.e., corrugated region  255  may include a circular structure with a rounded profile. 
     Diaphragm  250  may be composed of a crystalline material, e.g., a polycrystalline material or a nanocrystalline material. The diaphragm  250  may be composed of a conductive material, such as metal, or a semiconductive material, such as silicon, e.g., a polysilicon, nanocrystalline silicon, or an amorphous silicon. 
     Diaphragm  250  may be configured to actuate. Electrically-conductive component  220  may be configured to at least one of: provide a force to actuate the diaphragm  250  in response to an electrical signal transmitted to the electrically-conductive component  220  and provide an electrical signal in response to an actuation of the diaphragm  250 . 
       FIG. 3A-3D  show, in cross-section, a method of manufacturing a microelectromechanical component and the components at various stages of manufacture according to an embodiment of the disclosure.  FIG. 3A-3D  may correspond to  FIG. 2A-2D , and therefore, only differences between the figures may be discussed below. 
       FIG. 3A  shows process  300 A of forming a mask  330  over a layer  310 , the mask  330  including a structured surface  340 .  FIG. 3A  also depicts electrically conductive component  320 , e.g., an electrode.  FIG. 3A  differs from  FIG. 2A  in that it shows a greater cross-section of the arrangement of process  300 A. 
     Layer  310  may include a sacrificial portion  318 , e.g., a sacrificial oxide layer. Mask  330  may completely cover at least one surface of layer  310  (as well as sacrificial portion  318 ). 
     Additionally, process  300 A shows structured surface  340  of mask  330  having a plurality of structures having angular edges  341 . Structured surface  340  may contain a plurality of circular structures, e.g., ring-like structures. The structures may protrude from the mask  330 , or recesses may be formed in the mask  330 . The plurality of structures, e.g., circular structures, included in structured surface  340  may be concentric. 
       FIG. 3B  shows process  300 B of heating a region of a mask  330  including the structured surface  340  above a glass transition temperature of the mask  330  to smooth out edges  341  of the structured surface  340  to form a corrugated surface  345 . Arrow  344  represents the transfer of thermal energy, i.e., heating. 
     In process  300 B, the arrangement may include a corrugated surface  345  including a plurality of circular, or ring-like, structures. The plurality of structures of corrugated surface  345  may be concentric. Transitions between the structures may be smooth and wave-like, i.e., undulating or corrugated. Angular edges  341  of the structured surface  340  may be rounded due to the heating; for example, heating above the glass transition temperature of a material of the mask  330  causes the viscosity of the material to vary and reflow into a structure with a rounded profile. 
       FIG. 3C  shows process  300 C of etching the layer  310  covered by the mask  330 , the etching removing the mask  330  to carry over the corrugated surface  345  of the mask  330  into the layer  310  (e.g., sacrificial portion  318 ) and to form a corrugated surface  315  of the layer  310 . 
     In process  300 C, the corrugated surface  345  of mask  330  is carried over into the layer  310 , i.e., the plurality of circular, or ring-like structures of corrugated surface  345  are also formed in corrugated surface  315  of the layer  310 , for example. The plurality of structures of corrugated surface  315  may be concentric and have smooth or wave-like transitions between the structures, i.e., the corrugated surface  315  is undulating or corrugated. 
       FIG. 3D  shows process  300 D of forming a diaphragm  350  over the layer  310  (e.g., including sacrificial portion  318 , corrugated surface  315 ) to form a corrugated region  355  of the diaphragm  350  configured to actuate. 
     In process  300 D, the corrugated surface  315  of the layer  310  (or sacrificial portion  318 ) may serve as a mold for forming a diaphragm  350  over the layer  310  having a corrugated region  355 . Forming diaphragm  350  over corrugated surface  315  imparts structure, e.g., the plurality of circular, ring-like structures of corrugated surface  315  are imparted (or reproduced or molded) into diaphragm  350 , thus forming corrugated region  355 . Corrugated region  355  may then have a plurality of circular, or ring-like structures having a smooth, wave-like transition between structures. The structures of the corrugated region  355  may be concentric. Corrugated region  355  may have any number of structures, e.g.,  1  to  10  structures, or  6  structures (or corrugations). 
       FIG. 3E  shows process  300 A of forming a mask  330  over a layer  310 , the mask  330  including a structured surface  340 .  FIG. 3A  is a projection view of process  300 A in cross-section. 
     A circular, or ring-like, structure of structured surface  340  (as well as mask  330 ) may be depicted in  FIG. 3E . The structures may be spaced a distance from one another. This distance may vary or be uniform. The height and width of the structures may also vary or be uniform. 
     Similarly,  FIG. 3F  shows a projection view of a cross-section of process  300 B of heating a region of the mask  330  including the structured surface  340  above a glass transition temperature of the mask  330  to smooth out edges of the structured surface  340  to form a corrugated surface  345 . 
     In  FIG. 3F , a circular, or ring-like, structure of corrugated surface  345  may be observed. Rounded transitions between structures of corrugated surface  345  may also be seen, as well as concentric structures. 
     Diaphragm  350  may be configured to actuate. Electrically-conductive component  320  may be configured to at least one of: provide a force to actuate the diaphragm  350  in response to an electrical signal transmitted to the electrically-conductive component  320  and provide an electrical signal in response to an actuation of the diaphragm  350 . 
       FIG. 4A-4U  show, in cross-section, a method of manufacturing a microelectromechanical component and the components at various stages of manufacture according to an embodiment of the disclosure. 
     The method depicted in  FIG. 4A-4U  may be similar (or the same) to that of  FIG. 2A-2D , as well as  FIG. 3A-3F ; however,  FIG. 4A-4U  may include additional (or optional) processes not depicted in other figures. Again, descriptions of similarly numbered elements may not be repeated here in entirety (e.g., layer  210 , layer  310 , layer  410 ). 
       FIG. 4A  shows process  400 A including layer  410 . Layer  410  may be a substrate having a thickness. For example, the thickness of layer  410  may be based on various configurational requirements (or specifications) for the layer  410 , for example, the thickness of layer  410  may range from about 50 μm to about 1 mm, e.g., about 725 μm. Layer  410  may be provided for further processing. 
       FIG. 4B  shows process  400 B of providing etch stop layer  412  on layer  410 . Process  400 B may be optional. Etch stop layer  412  may be an oxide, e.g., an oxide of silicon, such as tetraethyl orthosilicate (TEOS). Etch stop layer  412  may prevent an etchant from etching any materials under the layer  412 . 
       FIG. 4C  shows process  400 C of providing a nitride layer  414  on layer  410  and providing a crystalline layer  416  on layer  410 . Nitride layer  414  may be a silicon nitride, e.g., Si x N y , such as Si 3 N 4 . Crystalline layer  416  may, for example, by a polysilicon layer. 
       FIG. 4D  shows process  400 D of segmenting crystalline layer  416 . Crystalline layer  416  may be etched to form multiple segments of crystalline layer  416 . The etching process may be selected so as to be suitable for the material of crystalline layer  416 . 
       FIG. 4E  shows process  400 E of providing an additional nitride layer  414  over crystalline layer  416  and etching nitride layers  414 . Nitride layers  414  and crystalline layer  416  may together form an electrically-conductive component  420 , e.g., an electrode or a backplate for a MEMS microphone. Etching nitride layers  414  may provide gaps  421 , or backplate holes, in electrically-conductive component  420 . 
     Gaps  421  allow a force (or incident pressure) to pass through electrically-conductive component  420  and impinge on other components (e.g., actuate or deflect diaphragm  450 , discussed below). The number of gaps  421  in electrically-conductive component  420  may be selected to optimize a balance between compliance (e.g., suppleness or flexibility of the component  420 ) and capacitance of the electrically-conductive component. For example, a large number of gaps  421  may result in that the electrically-conductive component  420  is too compliant and may deflect in response to a force. Too much compliance of electrically-conductive component  420  may negatively affect performance of the microelectromechanical component. Similarly, a large number of gaps  421  reduces the area of a surface of electrically-conductive component  420 , and may thus reduce the capacitance of electrically-conductive component  420 , which may, again, negatively affect performance of the electrically-conductive component  420 . Another consideration is that the number of gaps  421  may be related to the bandwidth of, e.g., a MEMS microphone, and may, for example over-damp a microphone if too few gaps  421  are provided. 
     A radius of gap  421  may be considered to affect the capacitance of electrically-conductive component  420 , e.g., a smaller radius may utilize fringing electric fields to address capacitance loss. 
       FIG. 4F  shows process  400 F of forming an oxide layer  418  on electrically-conductive component  420 . Oxide layer  418  may at least partially cover electrically-conductive component  420  (or completely cover all surfaces), i.e., gaps  421  may be filled in, as well as any other spaces in electrically-conductive component  420  with oxide layer  418 . 
     Oxide layer  418  may be an oxide of silicon, such as silicon dioxide or TEOS. Oxide layer  418  may then be annealed, i.e., heating and allowing atom diffusion to reduce the presence of dislocations. Oxide layer  418  may be planarized, e.g., by chemical-mechanical polishing (CMP) to provide a surface for further processing. 
       FIG. 4G  shows process  400 G of forming additional oxide layer  418 . As illustrated in  FIG. 4G , additional oxide layer  418  may be a further layer of oxide deposited on the oxide layer  418  surrounding (or covering) electrically-conductive component  420  or oxide layer  418  may be deposited to surround electrically-conductive component  420  and fill beyond a thickness of electrically-conductive component  420 . Oxide layer  418  may be annealed. 
       FIG. 4H  shows process  400 H of forming an additional etch stop layer  412 . An additional etch stop layer over the electrically-conductive component  420  may be optional. An additional etch stop layer  412  may prevent any components underneath it from being etched during further processing, i.e., the additional etch stop layer  412  may not be reactive to a particular etchant. In addition, etch stop layer  412  may be a dielectric characterized by having a low leakage current and high thermal stability. The additional etch stop layer  412  may be an oxide, e.g., silicon oxynitride (SiO x N y ), which may have an amorphous structure. 
       FIG. 4I  shows process  400 I of forming additional oxide layer  418  over an optional additional etch stop layer  412 . Additional oxide layer  418  may be formed from an oxide of silicon, as discussed above. Additional oxide layer  418  of process  400 I may provide a surface for further processing of additional components for the microelectromechanical component. Additional oxide layer  418  may, for example, be a sacrificial oxide layer, i.e., used as a mold for further processing. 
       FIG. 4J  shows process  400 J of forming a mask  430  over a layer  410 , the mask  430  including a structured surface  440 . Mask  430  may also be formed over electrically-conductive component  420 . 
     Mask  430  may be formed on layer  410  and then structured, e.g., forming a recess in the mask  430  or forming protrusions on mask  430  (or a combination of both) to form structured surface  440 . Alternatively or additionally, structured surface  440  of mask  430  may be formed in substantially a final profile (form) of the structured surface  440  on layer  410 . Structured surface  440  may have angular edges  441 . Structured surface  440  may be formed into a specified or desired shape, i.e., a topography or profile (e.g., a protrusion, a recess, steps, or a geometric shape). Similar to  FIG. 3E , structured surface  440  may have an overall circular, or ring-like, structure, and may be composed of at least one, e.g., a plurality, of concentric structures. Mask  430  may be a polymer e.g., a lacquer, a resin, a resist, or a photoresist (similar to mask  230 , mask  330 ) and layer  410  may be similar to that of layer  210  and layer  310 . 
       FIG. 4K  shows process  400 K of heating (or baking) a region of the mask  430  including the structured surface  440  above a glass transition temperature of the mask  430  to smooth out edges  441  of the structured surface  440  to form a corrugated surface  445 . Arrows  444  may represent transfer of thermal energy (heating). 
     As discussed above, a region of mask  430 , e.g., structured surface  440 , may be locally heated or the entire arrangement depicted in  400 J may be heated. Mask  430  may have a glass transition temperature, and upon substantially reaching this temperature, the viscosity of mask  430  (and structured surface  440 ) may vary, e.g., decrease, and the material of mask  440 , e.g., structured surface  440 , may flow. A profile of structured surface  440 , for example, may then be altered. Angular edges  441  may be rounded or smoothed out. Transitions between structures of the structured surface  440  may be smooth, thus forming a wave-like surface, i.e., an undulating or corrugated surface  445 . Mask  430 , or structured surface  440 , may be heated for a predefined period of time and (substantially) a predefined temperature. As discussed above, various factors affect the degree of transformation (reformation, alteration, or reflow) of mask  430 , for example, structured surface  440  in particular. 
     Corrugated surface  445  may be a smoothed-out, or rounded, version of structured surface  440 . As discussed above, corrugated surface  445  may include a plurality of rounded, ring-like structures, which may be concentric. 
       FIG. 4L  of process  400 L of etching the layer  410  covered by the mask  430 , the etching removing the mask  430  to carry over the corrugated surface  445  of the mask  430  into the layer  410  and to form a corrugated surface  415  of the layer  410 . For processing, layer  410  may be considered to include any component or elements (e.g., oxide layers  418 , etch stop layers  412 , and electrically-conductive component  420 ) in or on layer  410  not involved (or intended to be directly affected) in immediate processing, for example, oxide layer  418  may be analogous to sacrificial portion  318 , and may be considered part of layer  410 , which may together function as a substrate or structure to facilitate processing (which may also, as discussed below, form a part (an integrated part) of the microelectromechanical component in later processing or the manufactured component). 
     As discussed above, etching layer  410  may partially or completely remove mask  430  and corrugated surface  445  may be formed in layer  410  (for example, oxide layer  418 , which may be a sacrificial layer), i.e., etching mask  430  (including corrugated surface  445 ) may affect etching of layer  410  so that a corrugated surface  415  is formed (or reproduced or carried over into) in layer  410  (e.g., oxide layer  418 ). During process  400 L the overall thickness of layer  410  may be reduced, e.g., further reaction with an etchant may be stopped by (additional or optional) etch stop layer  412 , i.e., etch stop layer  412  may be a barrier preventing or hindering further etching below the layer  412 . Etching may additionally or alternatively be stopped (halted, interrupted, or ended) by other conventional methods. The etching process  400 L may be a selective etching process and may be a dry-etching process. 
       FIG. 4M  shows process  400 M of forming protrusion pattern  419  for diaphragm  450 . Process  400 M may be optional. Protrusion pattern  419  may be a cast, or a mold, for the formation of protrusions in further processing, i.e., protrusion pattern  419  is a cavity or void. Protrusion pattern  419  may be an arrangement of protrusions in a pattern or specified order. Individual cavities or voids may be cone-shaped, pyramid-shaped, or cylindrical. 
     Protrusion pattern  419  may be formed by removing a portion of oxide layer  418  (including optional etch stop layer  412 ). Oxide layer  418  (including etch stop layer  412 , i.e., an etchant that may be reactive with etch stop layer  412  may be selected, which may be the same or different from an etchant selected to etch oxide layer  418 ; as an example, an etch rate for etch stop layer  412  and oxide layer  418  may be substantially different with the same etchant) may be etched or removed mechanically. This process may create a void or cavity larger than intended for an actual structural protrusion. Additional oxide material may then be deposited in the void (or along surfaces, such as sidewalls, of the void) to reduce the volume of the void, which may then form a cone-like or pyramid-like void (e.g., a cast). 
       FIG. 4N  shows process  400 N of forming a diaphragm  450  over the layer  410  to form a corrugated region  455  of the diaphragm  450 , which is configured to actuate. Diaphragm  450  may further include protrusions  459 , which may be configured to prevent static friction (stiction) during further processing (the protrusions may reduce a physical contact area of the diaphragm  450  with another component, e.g., electrically-conductive component  420 ). When forming diaphragm  450  (or membrane), material of diaphragm  450  may be formed in (e.g., fill) the cavities of protrusion pattern  419 , thus forming the protrusions  459  on diaphragm  450 . 
     Forming diaphragm  450  over layer  410  including corrugated surface  415  may conform a region of diaphragm  450  to the corrugated surface  415 , and a corrugated region  455  may be produced in diaphragm  450 . Corrugated region  455  may have at least one, or a plurality, of structures corresponding to corrugated surface  415 . The structures of corrugated region  455  may be ring-like, or circular, and may be concentric. Corrugated region  455  may have a wave-like, or undulating region, with smooth transitions between structures, i.e., non-angular edges. Diaphragm  450  may be formed a predefined distance from electrically-conductive component  420 . 
     In other words, corrugated surface  415  (and protrusion pattern  419 ) may form a mold (or cast) for the formation of diaphragm  450 , including corrugated region  455 . A thickness of diaphragm  450  may be substantially uniform, therefore, for example, the topography of corrugated surface  215  may be formed (reproduced) in the profile of diaphragm  450  (in particular, corrugated region  455 ) when being formed or deposited. 
     Similar to diaphragm  250  and  350 , diaphragm  450  may be composed of a crystalline material, e.g., a polycrystalline material or a nanocrystalline material. The diaphragm  450  may be composed of a conductive material, such as metal, or a semiconductive material, such as silicon, e.g., a polysilicon, nanocrystalline silicon, or an amorphous silicon. 
     Diaphragm  450  may additionally (or optionally) be etched to define an outer boundary  451  of diaphragm  450 . For example, if diaphragm  450  is circular, the diameter of diaphragm  450  may be reduced, or the outer boundary  451  may be etched to form a specified shape or pattern, which may be a geometric shape. 
       FIG. 4O  shows process  400 O of forming additional oxide layer  418  over diaphragm  450 . Additional oxide layer  418  may at least partially (or completely) cover diaphragm  450 . As discussed above, oxide layer  418  may be formed from an oxide of silicon, e.g., tetraethyl orthosilicate. Additional oxide layer  418  may be annealed, and may be planarized, e.g., by a CMP process, to provide a surface for further processing. 
       FIG. 4P  shows process  400 P of forming a further protrusion pattern  419  for further protrusions  429  for further electrically-conductive component  422 . Additional oxide layer  418  may be structured to form a further protrusion pattern  419 , i.e., a pattern of voids or cavities. This process may create a void or cavity larger than intended for an actual structural protrusion. Additional oxide material may then be deposited in the void (or along surfaces, such as sidewalls, of the void) to reduce the volume of the void, which may then form a cone-like or pyramid-like void (e.g., a cast). 
     A further nitride layer  414  may then be deposited over diaphragm  450 , e.g., over additional oxide layer  418  including further protrusion pattern  419 . Further nitride layer  414  may be deposited in further protrusion pattern (which may be optional), for example, nitride material may be deposited in (or fill) the voids or cavities of further protrusion pattern  419 , thus forming a further nitride layer  414  having further protrusions  429 . Further protrusions  429  may reduce a contact area of further electrically-conductive component  422  in further processing with diaphragm  450 . Further protrusions  429  may thus reduce static friction (stiction) between further electrically-conductive component  422  and other components. As discussed above, further nitride layer  414  may be formed from, e.g., silicon nitride, Si x N y . 
     A further crystalline layer  416  may be formed on further nitride layer  414 . As discussed above, further crystalline layer  416  may be formed, e.g., from polysilicon. Further crystalline layer  416  be segmented, e.g., etched to form multiple segments of further crystalline layer  416 . 
       FIG. 4Q  shows process  400 Q of forming additional further nitride layer  414  on further crystalline layer  416 , thus forming further electrically-conductive component  422 ; forming additional oxide layer  418 ; and forming access points  460  to various components, such as layer  410 , electrically-conductive component  420 , diaphragm  450 , and further electrically-conductive component  422 . 
     Forming further electrically-conductive component  422  may also include etching further nitride layers  414  and further crystalline layer  416  to form further gaps  421  (as discussed above). Further electrically-conductive component  422  may include the protrusions  429 . 
     An additional further oxide layer  418  may be formed over further electrically-conductive component  422 . This oxide layer  418  may at least partially (or completely) cover, e.g., surround all surfaces of, further electrically-conductive component  422 . 
     Access points  460  may then be formed, for example, by etching through oxide layer(s)  418  and nitride layer(s)  414  to various electrically-conductive layers of the microelectromechanical component, e.g., electrically-conductive component  420 , further electrically-conductive component  422 , and diaphragm  450 , as well as layer  410 . 
       FIG. 4R  shows process  400 R of forming contacts  462  in access points  460 , e.g, forming a metallic or conductive contact, such as metallization. A negative mask or lift-off process may be used to deposit a metal on the arrangement in process  400 R. For example, titanium, platinum, or gold may be formed, or deposited. The metallic material may contact the various electrically-conductive layers of the microelectromechanical component, e.g., electrically-conductive component  420 , further electrically-conductive component  422 , and diaphragm  450 , as well as layer  410 , by at least partially filling access points  460 . Contacts  462  (e.g., contact pads) may be used to externally electrically contact the microelectromechanical component. 
       FIG. 4S  shows process  400 S of forming a passivation layer  464  at least partially on the microelectromechanical component, e.g., to passivate any exposed metallization (excluding portions of contacts  462 ). For example, a layer of silicon nitride may be deposited on further electrically-conductive component  422  and metallic contacts  462 . The layer of silicon nitride may then be etched to expose contacts  462  and provide an opening (as seen here in cross-section) above further electrically-conductive component  422 . The opening may be in the form of a geometric shape, e.g., a circle. 
       FIG. 4T  shows process  400 T of forming a recess  411  in layer  410 . Forming the recess  411  may include grinding a surface of layer  410 , e.g., a backside, or exposed surface of layer  410 , i.e., a surface of layer  410  not proximate to electrically-conductive component  420 . Grinding may be a process of physically removing material from layer  410 , such as abrasion (or abrasive cutting). Additionally or alternatively, recess  411  may be formed by deep reactive-ion etching, e.g., via the Bosch process (pulsed or time-multiplexed etching). The Bosch process, for example, may include repetitive (iterative) steps of isotropic etching and deposition of a passivation layer (including sidewalls of the targeted etch area), which may achieve a step-wise substantially vertical etch to a desired (predefined) depth, e.g., to electrically-conductive component  420  or to a region proximate to electrically-conductive component  420 . 
       FIG. 4U  shows process and microelectromechanical component  400 U of releasing electrically-conductive component  420 , diaphragm  450 , and further electrically-conductive component  422 , from any surrounding and intervening layers, e.g., oxide layers  418  and etch stop layers  412 . The components may be released by an etch process to remove, for example, portions of oxide layers  418  and etch stop layers  412 . As can be exemplarily seen in  FIG. 4U , oxide layers  418  and etch stop layers  412  may not be completely released and may form structural supports for the electrically-conductive component  420 , diaphragm  450 , and further electrically-conductive component  422 , while an intervening material between active regions of the components may be completely removed. Thus, the microelectromechanical component may be formed. 
     Microelectromechanical component  400 U may be a MEMS device, such as a transducer, or a microphone, or a dual-backplate (DBP) microphone. Diaphragm  450  may be configured to actuate. Electrically-conductive component  420  may be configured to at least one of: provide a force to actuate the diaphragm  450  in response to an electrical signal transmitted to the electrically-conductive component and provide an electrical signal in response to an actuation of the diaphragm  450 . 
     For example, in an aspect of the disclosure, the microelectromechanical component may be a MEMS microphone and a force, e.g., a pressure gradient, such as a mechanical wave (including a sound wave, as well as non-auditory mechanical waves or impulses), external fluid pressure (external from the component, including, for example, gauge pressure) may cause diaphragm  450  to actuate, or move, in relation to the magnitude of the force impinging the diaphragm  450 . Diaphragm  450  may have, for example, a capacitive relationship with electrically-conductive component  420  and/or further electrically-conductive component  422 . Actuation of diaphragm  450  may then change an electrically capacitive relationship, e.g., the magnitude of the capacitance, between, for example, diaphragm  450  and electrically-conductive component  420 , thus an electrical signal may be produced in electrically-conductive component  420 , for example, this change in capacitance may occur and be detected by circuitry connected to the electrically-conductive component  420  and/or diaphragm  450  (such circuitry  499 , which may, for example, be external to the microelectromechanical component or may be integrated with the microelectromechanical component and may be electrically contacted to contacts  462 ). 
     Diaphragm  450  may be biased by an external voltage, i.e., provided with a voltage, e.g., contacted at contact  462  for the diaphragm  450 , such as in a condenser microphone, or diaphragm  450  may, for example, maintain an embedded static electrical charge, such as in an electret microphone. 
     Alternatively or additionally, electrically-conductive component  420  (as well as further electrically-conductive component  422 ) may provide a force to actuate the diaphragm  450  in response to an electrical signal transmitted to the electrically-conductive component  420 . For example, the electrical signal may provide a voltage to electrically-conductive component  420  (and/or further electrically-conductive component  422 ), which may provide an electric field interaction or magnetic field interaction on diaphragm  450  (e.g., exert an electric force) causing diaphragm  450  to actuate. This actuation may produce a mechanical wave, e.g., a sound wave, thus allowing microelectromechanical component  400 U to operate as a speaker. 
     A DBP arrangement for a MEMS microphone may be advantageous, e.g., electrically-conductive component  420  and further electrically-conductive component  422  may be electrodes and form dual backplates for diaphragm  450 . As the MEMS microphone may have two backplates, sensitivity of the component may be increased due to the presence of two electrodes, or even more accurate measurement (or detection) by providing a second electrode. Sensitivity of the component may also be increased as the dual backplates allow for higher bias voltages, which may exert similar (or cancelling) electrostatic forces on, e.g., diaphragm  450 , which may reduce effects of pull-in (diaphragm attraction to an electrode due to electrostatic forces, which may lead to, e.g., diaphragm collapse). 
     Additionally, a diaphragm  450  having a corrugated region  455  may increase bandwidth and sensitivity of the component, e.g., due to increased compliance of the diaphragm  450 . The rounded, or smoothed out, transitions of corrugated region  455  avoid concentrations of internal stress, e.g., in an angular edge of diaphragm corrugation, when diaphragm  450  is actuated, which may, e.g., lead to component failure or inaccurate measurement. 
       FIG. 5A-5E  show, in cross-section, an aspect of the disclosure of a method of manufacturing a microelectromechanical component and the components at various stages of manufacture according to an embodiment of the disclosure. 
       FIG. 5A  shows process  500 A of forming a mask  530  over a layer  510 , the mask including a structured surface  540 . Layer  510  may be a substrate, which may, for example, be formed from: silicon, such as monocrystalline silicon, polycrystalline silicon, or nanocrystalline silicon; or an oxide, such as an oxide of silicon, e.g., TEOS. Mask  530  may be a polymer, e.g., a lacquer, a resin, a resist, or a photoresist. 
     Mask  530  may include structured surface  540 . Structuring the surface of mask  530  may vary the surface of the mask  530 , e.g., changing a profile of the mask  530 , patterning the mask  530 , forming a shape or shapes in the mask  530 . Structured surface  540  may have angular edges  541 , e.g., due to an etching process. A profile of structured surface  540  may, for example, be rectangular, trapezoidal, or be composed of a step-like profile. Structured surface  540  may include any surface that has been altered into a desired or specified form from depositing or forming of mask  530  on layer  510 . Structured surface  540  may include, for example, a protrusion, a recess, steps, or a geometric shape. The overall shape of structured surface  540  may be a circle (or ring). Structured surface  540  may also include a plurality of rings, which may be concentric. 
       FIG. 5B  shows process  500 B of heating a region of the mask  530  including the structured surface  240  above a glass transition temperature of the mask  530  to smooth out edges  541  of the structured surface  540  to form a corrugated surface  545 . Arrow  544  represents the transfer of thermal energy, i.e., heating. 
     A region of the mask  530  including the structured surface  540  may be locally heated or the entire arrangement depicted in process  500 B may be heated. For example, structured surface  540  may be locally heated with focused thermal energy, e.g., laser radiation for locally induced heating, i.e., structured surface  540  may be selectively exposed to a heat source. Alternatively or additionally, layer  510  including electrically-conductive component  520  and mask  530  (and structured surface  540 ) may be simultaneously exposed (e.g., a heat transfer) to a heat source. 
     Mask  530  may have a glass transition temperature and in process  500 B, may be heated above the glass transition temperature of mask  530 , i.e., of the material (or, e.g., materials) forming mask  530 , or heated substantially to the glass transition temperature of mask  530 . At the glass transition temperature, mask  530 , including structured surface  540 , may reflow, i.e., the viscosity of the material forming mask  530  may change, i.e., may be reduced, thus causing mask  530  or structured surface  540  to flow. Structured surface  540  (as well as mask  530 ) may be heated for a predefined time period. Structured surface  540  (as well as mask  530 ) may be heated to substantially a predefined temperature, e.g., taking into account heating device precision or tolerancing. The final profile or shape of the structured surface  540  may be defined by a variety of factors, such as the material of the mask  530 ; the temperature of the structured surface  540  (mask  530 ); the temperature of a heat source (or the medium that is transferring thermal energy to the structured surface  540 ); the amount of time the structured surface  540  is exposed to the heat source; the viscosity of the material forming the mask  530 , which may vary, e.g., due to a temperature of the material; external forces acting on the structured surface  540 , e.g., gravity; as well as internal forces of the structured surface  540 , e.g., cohesive forces related to surface tension. 
     Based on at least the above-identified parameters, structured surface  540  may assume, e.g., transform, into another shape or profile. The resultant shape may have a reduced surface area and may smooth out, or round, any edges  541  or the structured surface  540 . Structured surface  540  may form (e.g., may be transformed) into corrugated surface  545  of mask  530 . Corrugated surface  545  may be a smoothed out, or rounded, version of structured surface  540  (e.g., a rounded variant or version of structured surface  540 ). Corrugated surface  545  may be ring-like in overall shape, having a rounded profile or cross-section. Corrugated surface  545  may include a plurality of rounded, ring-like structures forming a plurality of rounded protrusions, e.g., an undulating or wave-like surface. 
       FIG. 5C  shows process  500 C of etching the layer  510  covered by the mask  530 , the etching removing the mask  530  to carry over the corrugated surface  545  of the mask  530  into the layer  510  and to form a corrugated surface  515  of the layer  510 . 
     Etching layer  510  may partially or completely remove mask  530 . Etching layer  510  may further carry over (i.e., reproduce or form in the layer) corrugated surface  545  of the mask  530 , i.e., a surface of layer  510 , after etching, may have a corrugated surface  515  where the mask  530  was etched. During process  500 C a portion of layer  510  may be removed, for example, a sacrificial oxide may be removed from layer  510 , i.e., the overall thickness of layer  510  may be reduced, while forming corrugated surface  515  in layer  510 . Mask  530  and structured surface  540  thus acts as a guide, affecting, or dictating in certain areas, the etching of the layer  510 . 
     Etching the layer  510  may involve a selective etching process, i.e., the etchant may be selected to etch different materials at different rates, or may not etch a particular material. Additionally or alternatively, a dry-etching process may be used. Alternatively, the mask  530  and layer  510  may be etched at substantially similar rates. 
       FIG. 5D  shows process  500 D of forming a diaphragm  550  over the layer  510  to form a corrugated region  555  of the diaphragm  550 . Layer  510  including corrugated surface  515  may be a mold for forming diaphragm  550 , i.e., layer  510  including corrugated surface  515  may be a pattern for the fabrication of diaphragm  550 . Corrugated surface  515  may then be imparted in diaphragm  550  when formed over layer  510  including corrugated surface  515 . Diaphragm  550  may be deposited over layer  510  and corrugated surface  515  with a substantially similar thickness, so that underlying features, e.g., protrusions and recesses, may be reproduced in diaphragm  550 , for example, the formation of corrugated region  555 . 
       FIG. 5E  shows process  500 E of removing a portion of the layer  510  to form a cavity  513  and release the diaphragm  550  and corrugated region  555 . Process  500 E may further include removing the portion of the layer  510  to form a mechanical support  517  for the diaphragm  550 . Diaphragm  550  may also include protrusions  559 , as discussed above. 
     Mechanical support  517  may provide a structure that anchors, or is a base structure or frame for, diaphragm  550 . Mechanical support  517  may be formed from layer  510 , i.e., layer  510  may be both a mold, and after release of diaphragm  550 , may also be formed as a mechanical support  517  for diaphragm  550 . Diaphragm  550  may be suspended from mechanical support  517 . 
     Release of diaphragm  550  may involve removing material, e.g., layer  510 , in physical contact with an active region of diaphragm  550 , whether the material is over or under diaphragm  550 , so that diaphragm  550  may actuate, e.g., in response to a force. 
       FIG. 5F  depicts a method of manufacturing a microelectromechanical component  501 , the method comprising: forming a mask over a layer, the mask comprising a structured surface  502 ; heating a region of the mask comprising the structured surface above a glass transition temperature of the mask to smooth out edges of the structured surface to form a corrugated surface  503 ; etching the layer covered by the mask, the etching removing the mask to carry over the corrugated surface of the mask into the layer and to form a corrugated surface of the layer  504 ; forming a diaphragm over the layer to form a corrugated region of the diaphragm  505 ; removing a portion of the layer to form a cavity to allow the corrugated region of the diaphragm to actuate  506 . Method  501  corresponds to the process described in detail above, e.g.,  FIG. 5A-5E  and related text. 
     In an Example 1 of an aspect of the disclosure, a method of manufacturing a microelectromechanical component, the method including: forming a mask over a layer, the mask comprising a structured surface; heating a region of the mask comprising the structured surface above a glass transition temperature of the mask to smooth out edges of the structured surface to form a corrugated surface; etching the layer covered by the mask, the etching removing the mask to carry over the corrugated surface of the mask into the layer and to form a corrugated surface of the layer; forming a diaphragm over the layer to form a corrugated region of the diaphragm configured to actuate; and forming an electrically-conductive component configured to at least one of: provide a force to actuate the diaphragm in response to an electrical signal transmitted to the electrically-conductive component and provide an electrical signal in response to an actuation of the diaphragm. 
     Example 2 may include the method of Example 1, wherein the diaphragm is actuated by a mechanical interaction, an electric field interaction, a magnetic field interaction, or any combination thereof. 
     Example 3 may include the method of Example 2, wherein the electrically-conductive component exerts the electric field interaction, the magnetic field interaction, or any combination thereof 
     Example 4 may include the method of Examples 1-3, further including: forming a further electrically-conductive component configured to at least one of: provide a further force to actuate the diaphragm in response to an electrical signal transmitted to the electrically conductive component and provide a further electrical signal in response to an actuation of the diaphragm. 
     Example 5 may include the method of Example 4, wherein the further electrically-conductive component exerts a further electric field interaction, a further magnetic field interaction, or any combination thereof. 
     Example 6 may include the method of Example 4, wherein the further electrically-conductive component is formed over the diaphragm. 
     Example 7 may include the method of Example 4, wherein the further electrically-conductive component is a further electrode. 
     Example 8 may include the method of Example 4, wherein forming the further electrically-conductive component further comprises: forming further protrusions extending toward the diaphragm, the protrusions configured to prevent static friction. 
     Example 9 may include the method of Examples 1-8, further comprising: forming an etch-stop layer that is non-reactive with an etchant used to etch the layer. 
     Example 10 may include the method of Example 9, wherein the etch-stop layer is formed over the electrically-conductive element. 
     Example 11 may include the method of Examples 9 and 10, further comprising: forming a further etch-stop layer that is non-reactive with the etchant. 
     Example 12 may include the method of Example 11, wherein the further etch-stop layer is formed over the diaphragm. 
     Example 13 may include the method of Example 1, wherein forming the structured surface of the mask comprises a lithographic process. 
     Example 14 may include the method of Example 13, wherein the lithographic process is a photolithographic process. 
     Example 15 may include the method of Example 13, wherein the lithographic process is a grey-scale lithographic process. 
     Example 16 may include the method of Example 1, wherein the mask comprises photoresist. 
     Example 17 may include the method of Example 1, wherein the structured surface comprises at least one recess. 
     Example 18 may include the method of Example 17, wherein the at least one recess comprises a plurality of concentric circular recesses. 
     Example 19 may include the method of Example 1, wherein the structured surface comprises at least one protrusion. 
     Example 20 may include the method of Example 19, wherein the structured surface comprises at least one circular protrusion. 
     Example 21 may include the method of Example 20, wherein the structured surface comprises a plurality of concentric circular protrusions. 
     Example 22 may include the method of Example 1, wherein heating the region of the mask above the glass transition temperature of the mask reflows the region of the mask. 
     Example 23 may include the method of Example 1, wherein heating the region of the mask above the glass transition temperature of the mask rounds the region of the mask according to a surface tension of the mask. 
     Example 24 may include the method of Example 1, wherein heating the region of the mask above the glass transition temperature of the mask changes a viscosity of the mask. 
     Example 25 may include the method of Example 1, wherein the region of the mask is heated to substantially a predefined temperature above the glass transition temperature of the mask. 
     Example 26 may include the method of Example 1, wherein the region of the mask is heated above the glass transition temperature of the mask for a predefined period of time. 
     Example 27 may include the method of Example 1, wherein etching the layer comprises: an anisotropic dry-etching process. 
     Example 28 may include the method of Example 1, wherein an etch rate of the mask and an etch rate of the layer are substantially similar. 
     Example 29 may include the method of Example 1, wherein an etch rate of the mask and an etch rate of the layer are substantially dissimilar. 
     Example 30 may include the method of Example 1, wherein the diaphragm comprises a crystalline material. 
     Example 31 may include the method of Example 34, wherein the crystalline material is silicon. 
     Example 32 may include the method of Example 1, wherein the diaphragm comprises a polycrystalline material. 
     Example 33 may include the method of Example 32, wherein the polycrystalline material is polysilicon. 
     Example 34 may include the method of Example 1, wherein the diaphragm comprises a nanocrystalline material. 
     Example 35 may include the method of Example 34, wherein the nanocrystalline material is nanocrystalline silicon. 
     Example 36 may include the method of Example 1, wherein the diaphragm comprises an amorphous silicon. 
     Example 37 may include the method of Example 1, wherein the diaphragm comprises a metal. 
     Example 38 may include the method of Example 1, wherein forming the diaphragm further comprises: forming protrusions extending toward the electrically-conductive component, the protrusions configured to prevent static friction. 
     Example 39 may include the method of Example 1, wherein the corrugated region comprises a circular structure with a rounded profile. 
     Example 40 may include the method of Example 1, wherein the corrugated region comprises a plurality of concentric circular structures having a rounded transition between the plurality of concentric circular structures. 
     Example 41 may include the method of Example 1, wherein the diaphragm is formed over the electrically-conductive component. 
     Example 42 may include the method of Example 1, wherein the diaphragm is formed a predefined distance from the electrically-conductive component. 
     Example 43 may include the method of Example 1, wherein the force to actuate the diaphragm is exerted by a mechanical interaction, an electric field interaction, a magnetic field interaction, or any combination thereof. 
     Example 44 may include the method of Example 1, wherein the electrically-conductive component is formed in the layer. 
     Example 45 may include the method of Example 1, wherein the electrically-conductive component is an electrode. 
     Example 46 may include the method of Example 1, wherein the electrically-conductive component provides the force to activate the diaphragm by an electric field interaction, a magnetic field interaction, or any combination thereof. 
     In an Example 47 of an aspect of the disclosure, a method of manufacturing a microelectromechanical component, the method including: forming a mask over a layer, the mask comprising a structured surface; heating a region of the mask comprising the structured surface above a glass transition temperature of the mask to smooth out edges of the structured surface to form a corrugated surface; etching the layer covered by the mask, the etching removing the mask to carry over the corrugated surface of the mask into the layer and to form a corrugated surface of the layer; forming a diaphragm over the layer to form a corrugated region of the diaphragm; and removing a portion of the layer to form a cavity and release the diaphragm and corrugated region. 
     Example 48 may include the method of Example 47, further including: removing the portion of the layer to form a mechanical support for the diaphragm. 
     Example 49 may include the method of Example 47, further including: forming an electrically-conductive component configured to at least one of: provide a force to actuate the diaphragm in response to an electrical signal transmitted to the electrically-conductive component and provide an electrical signal in response to an actuation of the diaphragm. 
     Example 50 may include the method of Examples 47-49, further including: forming a further electrically-conductive component configured to at least one of: provide a further force to actuate the diaphragm in response to an electrical signal transmitted to the electrically conductive component and provide a further electrical signal in response to an actuation of the diaphragm. 
     In an Example 51 of an aspect of the disclosure, a microelectromechanical component may include: an electrically-conductive component; a diaphragm disposed over the electrically-conductive component, the diaphragm comprising a corrugated region configured to actuate; and a further electrically-conductive component disposed over the diaphragm; wherein the electrically-conductive component is configured to at least one of: provide a force to actuate the diaphragm in response to an electrical signal transmitted to the electrically conductive component and provide an electrical signal in response to an actuation of the diaphragm; and wherein the further electrically-conductive component is configured to at least one of: provide a further force to actuate the diaphragm in response to a further electrical signal transmitted to the further electrically-conductive component and provide a further electrical signal in response to an actuation of the diaphragm. 
     Example 52 may include the method of Example 51, wherein the diaphragm further comprises: protrusions extending toward the electrically-conductive component, the protrusions configured to maintain a minimal distance between the diaphragm and the electrically-conductive component. 
     Example 53 may include the method of Example 51, wherein the further electrically-conductive component further comprises: further protrusions extending toward the diaphragm, the protrusions configured to maintain a minimal distance between the diaphragm and the further electrically-conductive component. 
     Example 54 may include the method of Example 51, wherein the electrically-conductive component is an electrode. 
     Example 55 may include the method of Example 51, wherein the further electrically-conductive component is a further electrode. 
     While the invention has been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is thus indicated by the appended claims, and all changes within the meaning and range of equivalency of the claims are therefore intended to be embraced.