Patent Publication Number: US-11651203-B2

Title: Three-dimensional oscillator structure

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. application Ser. No. 16/144,952, filed Sep. 27, 2018, which is incorporated by reference its entirety. 
    
    
     BACKGROUND 
     Neural networks may enable a wide range of computing tasks, for example, tasks related to artificial intelligence or machine learning. One option for neural network hardware may be oscillator neural networks (ONN). An ONN may include a plurality of oscillators communicatively coupled with an averager (e.g., a common node). The oscillators may work as synapses and the averager may work as a neuron connecting the synapses. The various synapses may hold respective weights G, and accept inputs F. The weights and inputs may determine a voltage which may shift the oscillators frequencies. The output of the ONN may be the amplitude of an alternating current (AC) signal, which may measure the degree of match (DOM) of the input pattern and weights. 
     However, some ONNs may suffer from one or more drawbacks. One drawback may be that the ONN may require a significant number of oscillators to form an array. For example, some ONNs may require hundreds of oscillators. Additionally, many ONNs may use complementary metal oxide semiconductor (CMOS) oscillators, which may be relatively large. This results in the need for multiple interconnecting wires which are difficult to route. Therefore, an ONN that uses hundreds of CMOS oscillators may have a very large footprint. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    depicts an example simplified circuit diagram of an oscillator, in accordance with various embodiments. 
         FIG.  2    depicts an example simplified cross-sectional view of various structures that may be used in an oscillator, in accordance with various embodiments. 
         FIG.  3    depicts an example simplified cross-sectional view of a structure to be used in an ONN, in accordance with various embodiments. 
         FIG.  4    depicts an alternative example simplified cross-sectional view of a structure to be used in an ONN, in accordance with various embodiments. 
         FIG.  5    depicts a simplified top-down view of a structure to be used in an ONN, in accordance with various embodiments. 
         FIG.  6    depicts an example technique for generating a structure to be used in an ONN, in accordance with various embodiments. 
         FIG.  7    illustrates an example device that may use various embodiments herein, in accordance with various embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings which form a part hereof, wherein like numerals designate like parts throughout, and in which is shown by way of illustration embodiments in which the subject matter of the present disclosure may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of embodiments is defined by the appended claims and their equivalents. 
     For the purposes of the present disclosure, the phrase “A or B” means (A), (B), or (A and B). For the purposes of the present disclosure, the phrase “A, B, or C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C). 
     The description may use perspective-based descriptions such as top/bottom, in/out, over/under, and the like. Such descriptions are merely used to facilitate the discussion and are not intended to restrict the application of embodiments described herein to any particular orientation. 
     The description may use the phrases “in an embodiment,” or “in embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments of the present disclosure, are synonymous. 
     The term “coupled with,” along with its derivatives, may be used herein. “Coupled” may mean one or more of the following. “Coupled” may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements indirectly contact each other, but yet still cooperate or interact with each other, and may mean that one or more other elements are coupled or connected between the elements that are said to be coupled with each other. The term “directly coupled” may mean that two or elements are in direct contact. 
     In various embodiments, the phrase “a first feature formed, deposited, or otherwise disposed on a second feature,” may mean that the first feature is formed, deposited, or disposed over the feature layer, and at least a part of the first feature may be in direct contact (e.g., direct physical or electrical contact) or indirect contact (e.g., having one or more other features between the first feature and the second feature) with at least a part of the second feature. 
     Various operations may be described as multiple discrete operations in turn, in a manner that is most helpful in understanding the claimed subject matter. However, the order of description should not be construed as to imply that these operations are necessarily order dependent. 
     Embodiments herein may be described with respect to various Figures. Unless explicitly stated, the dimensions of the Figures are intended to be simplified illustrative examples, rather than depictions of relative dimensions. For example, various lengths/widths/heights of elements in the Figures may not be drawn to scale unless indicated otherwise. 
     As noted above, CMOS based oscillators may be relatively large. For example, some CMOS oscillators may be on the order of a few to hundreds of micrometers (“microns” or “μm”) squared. However, oxide-based oscillators may be significantly smaller than the CMOS based oscillators. Some oxide-based oscillators may be based on oxides which exhibit an insulator-metal transition (IMT). Generally, IMT may refer to a phenomenon of a dramatic change of the resistance of the material in response to temperature, voltage, or strain. In some embodiments, one polarity of applied voltage to the IMT material may result in a transition from a high-resistance state (HRS) to a low resistance state (LRS) above a certain threshold absolute value of voltage. The opposite polarity of applied voltage to the IMT material may result in a transition from LRS to HRS above a certain threshold absolute of voltage. This may amount to a hysteresis in the current-voltage characteristic of a device with a salient “figure-8” shape. 
     Some legacy devices may include oxide oscillators positioned in the plane of the substrate. They may require additional circuit elements such as resistors or coupling capacitors. Additionally, many legacy devices have only coupled two oxide oscillators together, which may not be appropriate for use in an ONN which may require hundreds of oscillators. 
     By contrast, embodiments herein may relate to three-dimensional (3D) structures in which oscillators are placed between multiple metal interconnect layers. The averager and the ground may be routed vertically, and the oscillator input connections may be routed horizontally. These 3D structures may provide a very high density of oscillators in a relatively small integrated circuit area, which may be useful in ONNs. Additionally, in the structures, it may be easier to connect oscillators to various inputs, memory cells, averagers, or the ground in three dimensions rather than two. This higher density and ease of interconnection may result in smaller circuits which use shorter wires, which may improve delay of the circuit or energy use. 
     Generally, embodiments herein may relate to an oscillator that may be used in a neural network such as an ONN. The oscillator may include a nonlinear hysteretic element and a resistor coupled together in series. An input voltage may be applied to the hysteretic element. The output oscillating voltage may be produced at the note between the hysteretic element in the resistor. The oscillator may be coupled to an averager via a coupling capacitor. 
       FIG.  1    depicts an example simplified circuit diagram of an oscillator, in accordance with various embodiments. Specifically,  FIG.  1    depicts two alternative circuit diagrams of an oscillator  100  and  105 . 
     Specifically, in oscillator  100 , an input voltage may be provided at input node  110 . The voltage may be provided from the input node  110  to the hysteretic element  120 . The hysteretic element  120  may be coupled with a variable resistor  140  and a capacitor  130 . As used herein, a variable resistor may refer to a resistor whose resistance may change based on one or more internal or external factors. The variable resistor  140  may further be coupled with ground  150 , while the capacitor  130  is coupled with an output node  160  of the oscillator  100 . 
     Generally, the hysteretic element  120  may be configured to provide an oscillating voltage. The frequency of the oscillating voltage may be based on two elements. First, the frequency of the oscillating voltage may be based on the input voltage received by the input node  110 . This input voltage may be akin to the input F described above. The weight, G, may be considered to be a value of the variable resistor  140 . 
     Similarly, oscillator  105  may include an input node  115 , a hysteretic element  125 , a capacitor  135 , ground  155 , and an output node  165 , which may be respectively similar to input node  110 , hysteretic element  120 , capacitor  130 , ground  150 , and output node  160 . Further, oscillator  105  may include a fixed resistor  145 . As used herein, a fixed resistor may refer to a resistor whose resistance is preset. 
     Similarly to oscillator  100 , hysteretic element  125  may be configured to provide an oscillating voltage. Again, the frequency of the oscillating voltage may be based on two elements, an input F and a weight G. However, because the resistor  145  is a fixed resistor, the value of the resistor  145  may not be used for input of signals related to the weights. Rather, the weights may be stored remotely, and the input voltage received by input node  115  may be based on a difference between an input pattern F and a weight G obtained in a separate logic circuit. By varying the input voltage received at input node  115 , the output frequency of the oscillator  105  may be controlled. 
       FIG.  2    depicts an example simplified cross-sectional view of various structures that may be used in an oscillator, in accordance with various embodiments. Specifically,  FIG.  2    depicts a hysteretic element  203 , a capacitor  205 , a variable resistor  210 , and a fixed resistor  215  which may respectively be similar to hysteretic elements  120  or  125 , capacitors  130  or  135 , variable resistor  140 , or fixed resistor  145 . 
     The hysteretic element  203  may include an IMT switch material  225  between two electrodes  220 . The electrodes  220  may be, for example, a conductive material such as copper or some other material. The IMT switch material  225  may be, for example, an oxide material such as vanadium dioxide (VO2), niobium dioxide (NbO2), tantalum dioxide (TaO2), titanium oxide (Ti3O5), titanium (III) oxide (Ti2O3), lanthanum carbonate (LaCo3), samarium nickelate (SmNiO3), or some other appropriate material that exhibits IMT such as chalcogenide-based threshold switches. Such threshold switch materials are alloys which include sulfur (S), selenium (Se), or tellurium (Te). 
     The capacitor  205  may include a dielectric material  235  between two electrodes  230 . Similarly to electrodes  220 , electrodes  230  may be formed of a conductive material such as copper or some other conductive material. The dielectric material  235  may be, for example, porcelain, ceramic, mica, glass, plastic, or an oxide material. 
     The variable resistor  210  may include a variably resistive element  245  between two electrodes  240 . Similarly to electrodes  220 , electrodes  240  may be formed of a conductive material such as copper or some other conductive material. In some embodiments, the variably resistive element  245  may be a phase change material. For example, the phase change material may be a chalcogenide glass such as germanium-antimony-tellurium (Ge X Sb Y Te Z  or GST) which may be doped by additional elements such as silicon (Si), indium (In), or some other dopant material. Additionally or alternatively, the variably resistive element  245  may include a filamentary oxygen vacancy resistive switching material such as those based on tantalum pentoxide (Ta2O5), hafnium dioxide (HfO2), or some other oxide. Additionally or alternatively, the variably resistive element  245  may include an interfacial resistive switching material such as a material based on a conductive oxide. Indium tin oxide is an example of a conductive oxide. A different type of a conductive oxide may be a sub-stoichiometric oxide, such as titanium sub-oxide (TiO2-x). Additionally or alternatively, the variably resistive element  245  may be a conductive bridge filament material stuck such as based on copper (Cu), silver (Ag), or cobalt (Co) electrodes in contact with an atomic layer deposition (ALD) oxide such as aluminum oxide (Al2O3), silicon oxide (SiO2), HfO2, etc. It will, however, be understood that the above-listed oxide-based materials are intended as example materials, and other embodiments may use a non-oxide-based material that exhibits IMT properties. 
     Generally, the resistive element  245  may act as a sort of random-access memory (RAM). For example, in some embodiments the resistive element  245  may act similar to a resistive RAM (RRAM). In other embodiments, the resistive element  245  may act as a conductive bridge RAM (CBRAM). 
     In some embodiments, the variable resistor  210  may be replaced by a floating gate transistor for which channel resistance may be varied by a charge stored on the floating gate. Generally, it will be understood that embodiments that are discussed herein with respect to a variable resistor may act similarly if the variable resistor is replaced by the floating gate transistor. 
     The fixed resistor  215  may be, for example, a wire formed of a resistive material. For example, in some embodiments the wire may include Cu, tungsten (W), ruthenium (Ru), tantalum (Ta), or some other material. 
     Generally, the elements of  FIG.  2    may be used in 3D integration of oscillators into an array which is amenable to a batch fabrication. Specifically, the array may be a structure that may be used in an ONN. Generally, the ground and the averager nodes may be routed as vertical columns. Oscillators may be placed over multiple stacked metal interconnect layers. Horizontal wires may connect the oscillators to coupling capacitors. 
       FIG.  3    depicts an example of a structure  300  which may include a plurality of oscillators  340 . The structure  300  may be appropriate, for example, for use in an ONN. Generally, the structure  300  may include a substrate  313 . The substrate  313  may be, for example, a motherboard of a computing device such as a server, an interposer, or some other substrate  313 . The substrate  313  may include one or more conductive routing elements such as traces, vias, etc. In some embodiments, the substrate  313  may be cored or coreless, and have one or more electrical interconnects on one or more sides of the substrate  313 . 
     The substrate  313  may be coupled with a plurality of metal plates  320  and  325 . The metal plates  320  and  325  may be formed of a conductive material such as copper, gold, etc., and may be electrically coupled with one or more routing elements of the substrate. It will be understood that although the elements shown in  FIG.  3    are metal plates  320  and  325 , in other embodiments one or more of the metal plates  320  and  325  may be replaced by a different type of electrical interconnect such as a solder bump, a redistribution layer (RDL) line, or some other electrical interconnect. In some embodiments, the metal plates  320 / 325  may be considered to be “pads” of the substrate  313 , while in other embodiments the metal plates  320 / 325  may be a different type of metal plate. 
     Respective ones of the metal plates  320  and  325  may be coupled with columns  330  and  335 . Generally, as shown in  FIG.  3   , the columns  330 / 335  may be parallel with a vertical axis of the structure  300 . Specifically, the column  330  may be electrically coupled, by the metal plate  320  and through a conductive element of the substrate  313 , with ground. The ground may be similar to ground  150  or  155  of  FIG.  1   . Similarly, the column  335  may be coupled, by the metal plate  325  and through a conductive element of the substrate  313 , with an averager circuit of the ONN. The averager circuit may be, for example, some form of hardware, software, or firmware capable of performing an averaging function for the ONN. 
     The structure  300  may include a plurality of oscillators  340 . Respective ones of the oscillators  340  may include a hysteresis element  303 , a capacitor  205 , and a variable resistor  310 , which may be respectively similar to hysteresis element  203 , capacitor  205 , and variable resistor  210 . The hysteresis element  303  may be coupled with a voltage input  350 , and a wordline  355  may communicatively couple the hysteresis element  303 , and capacitor  305 , and the variable resistor  310  to one another. The voltage input  350  may be similar to input node  110  of  FIG.  1   , and be configured to provide an input voltage to the oscillator  340 . The wordline  355  may be a communicative line that serves one or both of two functions. First, the wordline  355  may electrically couple the hysteresis element  303 , the capacitor  305 , and the variable resistor  310  to one another. Additionally, the wordline  355  may be coupled with an element external to the structure  300  which may deliver one or more signals to the variable resistor  310 . The variable resistor  310  may, based on the received signals, set the resistance value of the variable resistor  310  as described above. 
     As can be seen, the oscillator  340  may be coupled with the column  335 . Specifically, the topmost electrode of the capacitor  305  may be coupled with the column  335 . Similarly, the variable resistor  310  may be coupled with a connecting wire  345 , which in turn may be electronically coupled with the column  330 . It will be understood that the specific configuration and connections of an oscillator  340  of  FIG.  3    may generally correspond to the circuit diagram of the oscillator  100  of  FIG.  1   , and function in a manner similar to that described above with respect to  FIG.  1   . 
       FIG.  4    depicts an alternative example simplified cross-sectional view of a structure  400  to be used in an ONN, in accordance with various embodiments. The structure  400  may be similar to structure  300  in many ways. Specifically, the structure  400  may include a substrate  413 , metal plates  420  and  425 , and columns  430  and  435  which may be respectively similar to substrate  313 , metal plates  320 / 325 , and columns  330 / 335 . 
     The structure  400  may further include an oscillator  440  which may include elements similar to those of oscillator  340 . Specifically, the oscillator  440  may include a hysteretic element  403  coupled with a voltage input  450 , which may be similar to hysteretic element  303  and voltage input  350 . The oscillator may further include a capacitor  405  coupled with column  435 , which may be similar to capacitor  305 . 
     The oscillator  440  may further include a fixed resistor  415 , which may be similar to fixed resistor  215 . The oscillator may further include a wordline  455  that couples the fixed resistor  415  to the hysteretic element  403  and the capacitor  405 . In this embodiment, the fixed resistor  415  may have a fixed resistive value. Therefore, the wordline  455  may not be coupled with an external source that is configured to deliver a signal to a variable resistor. Rather, the wordline  455  may be configured to electrically couple the hysteretic element  403 , the capacitor  405 , and the fixed resistor  415 . Similarly to  FIG.  3   , it will be understood that the specific configuration and connections of an oscillator  440  of  FIG.  4    may generally correspond to the circuit diagram of the oscillator  105  of  FIG.  1   , and function in a manner similar to that described above with respect to  FIG.  1   . 
     It will be understood that the structures  300  and  400  may be highly simplified, and other embodiments may have additional elements such as various filters, additional elements such as resistors/capacitors, etc. within the structures  30 / 4000  or inserted between various elements of the structures  300 / 400 . Additionally, for the sake of clarity of the Figures only certain elements of the Figures are enumerated. It will be understood that un-numbered elements within the Figures may share characteristics with similar numbered elements, even if those elements are not specifically addressed in this description. 
     Additionally, it will be understood that the Figures are intended as examples, and in other embodiments the structures  300  or  400  may have more or fewer elements than are depicted in  FIG.  3  or  4   . For example, in some embodiments the structures  300  or  400  may have more or fewer oscillators  340 / 440  than illustrated in the Figures. In some embodiments, one or more of the columns  330 / 335 / 430 / 435  may be taller/shorter/wider/narrower/etc. than depicted in the Figures. In some embodiments, even though the columns  330 / 335 / 430 / 435  are depicted as perpendicular to the surface of the substrate  413 , in other embodiments one or more of the columns may be angled in some manner with respect to the surface or another one of the columns. For example, in some embodiments the oscillators  340 / 440  may be generally arranged in a vertical pattern while the columns  330 / 335 / 430 / 435  are arranged in a generally horizontal pattern with respect to the surface of the substrate  313 / 413 . Other alternatives may be present in other embodiments. 
       FIG.  5    depicts a simplified top-down view of a structure  500  to be used in an ONN, in accordance with various embodiments. Specifically, the structure  500  may include a substrate  513 , which may be similar to substrates  313 / 413 . The structure  500  may further include a plurality of columns  530  and  535 , which may be similar to columns  330 / 430  and  335 / 435 , respectively. Generally, even though each of the columns in  FIG.  5    may not be specifically enumerated, they may be assumed that the columns with the darker shading may be similar to columns  535 , and that columns without shading may be similar to columns  530 . The structure  500  may further include a plurality of oscillators  540 , which may be similar to oscillators  340  or  440 . 
     As can be seen, respective ones of the columns  530  or  535  may be coupled with a plurality of oscillators  540 . Specifically, in some embodiments the columns  530 , which may correspond to the columns used for coupling to ground in  FIG.  3  or  4   , may be coupled with one, two, three, or four oscillators  540 . Additionally, in some embodiments the columns  535 , which may correspond to the columns used for coupling to an averager in  FIG.  3  or  4   , may be coupled with one, two, three, or four oscillators  540 . 
     It will be understood that the structure  500  is intended as a highly simplified example of a structure which may be used in an ONN. For example, as noted above, an ONN may require on the order of hundreds of oscillators such as oscillators  540 . Therefore, in some embodiments the structure  500  may include on the order of tens, hundreds, or thousands of columns  530  or  535 . Additionally, it will be understood that in some embodiments the columns  530 / 535  may not be arranged in a general grid pattern as depicted in  FIG.  5   . Rather, in some embodiments the columns may be arranged in a curved pattern, a pattern with gaps, a random pattern, or some other pattern. The pattern of the columns  530  or  535  may be based on, for example, workload requirements, size restrictions, cost restrictions, design considerations, or some other factor related to the structure  500 . In some embodiments, even though the columns  530 / 535  are depicted as generally circular, in other embodiments the columns  530 / 535  may have a cross-section that may be square, rectangular, triangular, or some other cross-section. 
     Additionally, as can be seen in  FIG.  3  or  4   , a structure such as structures  300  or  400  may have a plurality of oscillators stacked vertically. Similarly, the structure  500  may have a plurality of oscillators such as oscillators  540  stacked vertically. However, because the structure  500  is a simplified top-down view, only a single oscillator  540  may be shown where a plurality of oscillators are present. It may also be understood that additional filters, resistors, capacitors, metal plates, etc. may be present in the structure of  FIG.  5   , but may not be depicted for the sake of clarity of the Figure. 
       FIG.  6    depicts an example technique for generating a structure to be used in an ONN, in accordance with various embodiments. Specifically,  FIG.  6    will be described with respect to the structure  300  of  FIG.  3   . However, it will be understood that the technique described in  FIG.  6    may be applied to the structures of  FIG.  4   ,  FIG.  5   , or some other structure to be used in an ONN with or without modification. 
     The technique may include coupling, at  605 , a first column with a substrate. The column may be similar to, for example, column  335 . The substrate may be similar to, for example, substrate  313 . Generally, the column may be parallel to a vertical axis of the structure, and the structure may further include a lateral axis that is perpendicular to the vertical axis. 
     The technique may further include coupling, at  610 , a second column to the substrate. The column may be similar to, for example, column  330 . In embodiments, the second column may be generally parallel to the first column. 
     The technique may further include coupling, at  615 , a first oscillator to the first column and the second column. The oscillator may be similar to, for example, oscillator  340 . The oscillator may be at a first location along the vertical axis of the structure. The technique may further include coupling, and  620 , a second oscillator to the first column and the second column, wherein the second oscillator is at a second location along the vertical axis. For example, as can be seen in  FIG.  3   , two oscillators  340  may be stacked vertically, and coupled with the columns  330  and  335  at different locations along the vertical axis. 
     It will be understood that this example technique is one example embodiment, and in some embodiments certain of the elements of the technique may be performed in conjunction with one another, or in a different order than depicted in  FIG.  6   . For example, in some embodiments elements  610  may be performed prior to, or concurrently with, elements  605 . 
       FIG.  7    illustrates an example computing device  1500  suitable for use with various of the ONNs or oscillators discussed herein. 
     As shown, computing device  1500  may include one or more processors or processor cores  1502  and system memory  1504 . For the purpose of this application, including the claims, the terms “processor” and “processor cores” may be considered synonymous, unless the context clearly requires otherwise. The processor  1502  may include any type of processors, such as a CPU, a microprocessor, and the like. The processor  1502  may be implemented as an integrated circuit having multi-cores, e.g., a multi-core microprocessor. The computing device  1500  may include mass storage devices  1506  (such as diskette, hard drive, volatile memory (e.g., dynamic random access memory (DRAM), compact disc read-only memory (CD-ROM), digital versatile disk (DVD), and so forth)). In general, system memory  1504  and/or mass storage devices  1506  may be temporal and/or persistent storage of any type, including, but not limited to, volatile and non-volatile memory, optical, magnetic, and/or solid-state mass storage, and so forth. Volatile memory may include, but is not limited to, static and/or DRAM. Non-volatile memory may include, but is not limited to, electrically erasable programmable read-only memory, phase change memory, resistive memory, and so forth. In some embodiments, one or both of the system memory  1504  or the mass storage device  1506  may include computational logic  1522 , which may be configured to implement or perform, in whole or in part, one or more instructions that may be stored in the system memory  1504  or the mass storage device  1506 . In other embodiments, the computational logic  1522  may be configured to perform a memory-related command such as a read or write command on the system memory  1504  or the mass storage device  1506 . 
     The computing device  1500  may further include input/output (I/O) devices  1508  (such as a display (e.g., a touchscreen display), keyboard, cursor control, remote control, gaming controller, image capture device, and so forth) and communication interfaces  1510  (such as network interface cards, modems, infrared receivers, radio receivers (e.g., Bluetooth), and so forth). 
     The communication interfaces  1510  may include communication chips (not shown) that may be configured to operate the device  1500  in accordance with a Global System for Mobile Communication (GSM), General Packet Radio Service (GPRS), Universal Mobile Telecommunications System (UMTS), High Speed Packet Access (HSPA), Evolved HSPA (E-HSPA), or Long-Term Evolution (LTE) network. The communication chips may also be configured to operate in accordance with Enhanced Data for GSM Evolution (EDGE), GSM EDGE Radio Access Network (GERAN), Universal Terrestrial Radio Access Network (UTRAN), or Evolved UTRAN (E-UTRAN). The communication chips may be configured to operate in accordance with Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Digital Enhanced Cordless Telecommunications (DECT), Evolution-Data Optimized (EV-DO), derivatives thereof, as well as any other wireless protocols that are designated as 3G, 4G, 5G, and beyond. The communication interfaces  1510  may operate in accordance with other wireless protocols in other embodiments. 
     The computing device  1500  may further include or be coupled with a power supply. The power supply may, for example, be a power supply that is internal to the computing device  1500  such as a battery. In other embodiments the power supply may be external to the computing device  1500 . For example, the power supply may be an electrical source such as an electrical outlet, an external battery, or some other type of power supply. The power supply may be, for example AC, direct current (DC) or some other type of power supply. The power supply may in some embodiments include one or more additional components such as an AC to DC convertor, one or more downconverters, one or more upconverters, transistors, resistors, capacitors, etc. that may be used, for example, to tune or alter the current or voltage of the power supply from one level to another level. In some embodiments the power supply may be configured to provide power to the computing device  1500  or one or more discrete components of the computing device  1500  such as the processor(s)  1502 , mass storage  1506 , I/O devices  1508 , etc. 
     The above-described computing device  1500  elements may be coupled to each other via system bus  1512 , which may represent one or more buses. In the case of multiple buses, they may be bridged by one or more bus bridges (not shown). Each of these elements may perform its conventional functions known in the art. The various elements may be implemented by assembler instructions supported by processor(s)  1502  or high-level languages that may be compiled into such instructions. 
     The permanent copy of the programming instructions may be placed into mass storage devices  1506  in the factory, or in the field, through, for example, a distribution medium (not shown), such as a compact disc (CD), or through communication interface  1510  (from a distribution server (not shown)). That is, one or more distribution media having an implementation of the agent program may be employed to distribute the agent and to program various computing devices. 
     The number, capability, and/or capacity of the elements  1508 ,  1510 ,  1512  may vary, depending on whether computing device  1500  is used as a stationary computing device, such as a set-top box or desktop computer, or a mobile computing device, such as a tablet computing device, laptop computer, game console, or smartphone. Their constitutions are otherwise known, and accordingly will not be further described. 
     In various implementations, the computing device  1500  may comprise one or more components of a data center, a laptop, a netbook, a notebook, an ultrabook, a smartphone, a tablet, a personal digital assistant (PDA), an ultra mobile PC, a mobile phone, or a digital camera. In further implementations, the computing device  1500  may be any other electronic device that processes data. 
     In some embodiments, elements of the computing device  1500  may be used in an ONN such as those described herein. For example, the processor(s)  1502  may serve as the averager nodes described herein. Specifically, the processor(s)  1502  may be communicatively coupled with one or more of the pillars  335 / 435 / 535 . In this way, the processor  1502  may implement the averager node functionality based on the inputs from the oscillators  340 / 440 / 540  coupled with the various pillars  335 / 435 / 535 . 
     EXAMPLES OF VARIOUS EMBODIMENTS 
     Example 1 includes a structure to be used in a neural network, wherein the structure comprises: a first column to couple with a face of a substrate, wherein the face of the substrate defines a lateral plane parallel to the face of the substrate and a vertical axis perpendicular to the lateral plane, wherein the first column is parallel to the vertical axis; a second column to couple with the face of the substrate, wherein the second column is parallel to the vertical axis; a capacitor structure electrically coupled with the first column; an insulator-metal transition (IMT) structure electrically coupled with the first column, wherein the capacitor structure is electrically positioned between the IMT structure and the first column; and a resistor structure electrically coupled with the IMT structure and the second column, wherein the resistor structure is electrically positioned between the second column and the IMT structure. 
     Example 2 includes the structure of example 1, further comprising a voltage line electrically coupled with the IMT structure, wherein the IMT structure is electrically positioned between the voltage line and the capacitor. 
     Example 3 includes the structure of example 1, wherein the first column is to couple with averaging logic of the neural network. 
     Example 4 includes the structure of example 1, wherein the second column is to couple with ground of the substrate. 
     Example 5 includes the structure of any of examples 1-4, wherein the capacitor structure includes a first electrode, a second electrode, and a dielectric material between the first and second electrodes. 
     Example 6 includes the structure of any of examples 1-4, wherein the IMT structure includes a first electrode, a second electrode, and an oxide material positioned between the first electrode and the second electrode. 
     Example 7 includes the structure of any of examples 1-4, wherein the resistor structure includes a first electrode and a second electrode and a variable resistor positioned between the first electrode and the second electrode. 
     Example 8 includes the structure of example 7, wherein the variable resistor is a resistive random-access memory (RRAM), a conductive bridge random-access memory (CBRAM), or a phase change material (PCM). 
     Example 9 includes the structure of example 7, wherein the variable resistor is a filamentary oxygen vacancy resistive switching material, an interfacial resistive switching material, or a conductive bridge filament material. 
     Example 10 includes the structure of example 7, further comprising a wordline coupled with the variable resistor, wherein the wordline is to deliver a signal related to a desired resistance setting of the variable resistor. 
     Example 11 includes the structure of example 7, wherein the variable resistor is a floating gate transistor. 
     Example 12 includes the structure of any of examples 1-4, wherein the resistor structure includes a wire. 
     Example 13 includes the structure of example 12, wherein the wire is formed of tungsten (W) or copper (Cu). 
     Example 14 includes a structure that is a portion of a neural network, wherein the structure comprises: a substrate with a face, wherein the face defines a lateral plane parallel to the face of the substrate and a vertical axis perpendicular to the lateral plane; a first plurality of columns, wherein respective ones of the first plurality of columns are parallel to the vertical axis and are electrically coupled with averaging logic of the neural network; a second plurality of columns, wherein respective ones of the second plurality of columns are parallel to the vertical axis and are electrically coupled with a ground of the substrate; and an oxide oscillator electrically coupled with and electrically positioned between a first column of the first plurality of columns and a second column of the second plurality of columns, wherein the oxide oscillator includes: a capacitor structure electrically coupled with the first column; an insulator-metal transition (IMT) structure electrically coupled with the first column, wherein the capacitor structure is electrically positioned between the IMT structure and the first column; and a resistor structure electrically coupled with the IMT structure and the second column, wherein the resistor structure is electrically positioned between the second column and the IMT structure. 
     Example 15 includes the structure of example 14, wherein the oxide oscillator is a first oxide oscillator, and further comprising a second oxide oscillator electrically coupled with and electrically positioned between the first column and a third column of the second plurality of columns. 
     Example 16 includes the structure of example 15, further comprising a first voltage line electrically coupled with the IMT structure of the first oxide oscillator and a second voltage line electrically coupled with the IMT structure of the second oxide oscillator. 
     Example 17 includes the structure of example 16, wherein the first voltage line and the second voltage line are to deliver a same voltage to the first oxide oscillator and the second oxide oscillator, and wherein the resistor structure of the first oxide oscillator is a variable resistor. 
     Example 18 includes the structure of example 16, wherein the first voltage line and the second voltage line are to deliver different voltages to the first oxide oscillator and the second oxide oscillator, and wherein the resistor structure of the first oxide oscillator is a constant resistor. 
     Example 19 includes the structure of example 15, wherein the first oxide oscillator and the second oxide oscillator are coupled with one another by the first column. 
     Example 20 includes a method of forming a structure for use in a neural network, the method comprising: coupling a first column with a substrate, wherein the column is parallel to a vertical axis of the structure, and wherein the vertical axis is perpendicular to a lateral axis of the structure; coupling a second column to the substrate, wherein the second column is parallel to the first column; coupling a first oscillator to the first column and the second column, wherein the first oscillator is at a first location along the vertical axis; and coupling a second oscillator to the first column and the second column, wherein the second oscillator is at a second location along the vertical axis. 
     Example 21 includes the method of example 20, wherein the first column is coupled with an averaging logic of the neural network, and the second column is coupled with a ground of the substrate. 
     Example 22 includes the method of examples 20 or 21, wherein the first oscillator includes: a capacitor structure electrically coupled with the first column; an insulator-metal transition (IMT) structure electrically coupled with the first column, wherein the capacitor structure is electrically positioned between the IMT structure and the first column, and wherein the IMT structure is further electrically coupled with a voltage rail such that the IMT structure is electrically positioned between the voltage rail and the capacitor structure; and a resistor structure electrically coupled with the IMT structure and the second column, wherein the resistor structure is electrically positioned between the second column and the IMT structure. 
     Example 23 includes the method of example 22, wherein the IMT structure includes an oxide material. 
     Example 24 includes the method of examples 20 or 21, further comprising: coupling a third column with the substrate; and coupling a third oscillator to the first column and the third column, wherein the third oscillator is as the first location along the vertical axis. 
     Example 25 includes the method of example 24, further comprising coupling a fourth oscillator to the first column and the third column, wherein the fourth oscillator is at a third location along the vertical axis. 
     Example 26 includes the method of example 24, wherein the first oscillator, the second oscillator, and the third oscillator are electrically coupled with one another by the first column. 
     Various embodiments may include any suitable combination of the above-described embodiments including alternative (or) embodiments of embodiments that are described in conjunctive form (and) above (e.g., the “and” may be “or”). Furthermore, some embodiments may include one or more articles of manufacture (e.g., non-transitory computer-readable media) having instructions, stored thereon, that when executed result in actions of any of the above-described embodiments. Moreover, some embodiments may include apparatuses or systems having any suitable means for carrying out the various operations of the above-described embodiments. 
     The above description of illustrated embodiments, including what is described in the Abstract, is not intended to be exhaustive or limiting as to the precise forms disclosed. While specific implementations of, and examples for, various embodiments or concepts are described herein for illustrative purposes, various equivalent modifications may be possible, as those skilled in the relevant art will recognize. These modifications may be made in light of the above detailed description, the Abstract, the Figures, or the claims.