Structure and method for inductor having winding in which first segment is connected to two second segments

Abstract

The present disclosure provides a structure and method for an inductor having a winding in which a first segment is connected to two second segments. An inductor according to the present disclosure includes a plurality of windings coupled together in series around a magnetic core. At least one of the plurality of windings includes a first segment located in the first wiring layer and extending over a width of the magnetic core. The second segment is within the second wiring layer and is coupled to the first segment by a vertical interconnect. The second segment includes two sub-segments separated by a gap along the length of the magnetic core.

Description

Technical Field

[0001] The present disclosure provides structures and methods for an inductor having a winding where a first segment is connected to two second segments. Background Art

[0002] Integrating a soft magnetic material (i.e., a material that can be magnetized or demagnetized at relatively low energy levels) into an integrated circuit (IC) is beneficial for device performance, especially in the case of inductors, transformers, and / or other components that operate using magnetic fields. However, due to magnetic flux saturation generated by the magnetic field within the soft magnetic material, the maximum current achievable in a component characterized by a soft magnetic material is limited in a device. That is, when the magnetic field strength in an inductor is too high, the current does not increase beyond a specific maximum value, which results in the inductor being functionally indistinguishable from other implementations that rely on air gaps and / or other open spaces as the medium for the magnetic field. A hybrid device structure that combines a soft magnetic material with empty space can provide a higher saturation current but undesirably limits the magnetic flux density. Summary of the Invention

[0003] Exemplary aspects of the present disclosure are designed to address the problems described herein and / or other problems not discussed.

[0004] Embodiments of the present disclosure provide a structure including: an inductor including a plurality of windings coupled together in series around a magnetic core, wherein at least one of the plurality of windings includes: a first segment located in a first wiring layer and extending across the width of the magnetic core; and a second segment located within a second wiring layer and coupled to the first segment by a vertical interconnect, wherein the second segment includes two sub-segments separated by a gap along the length of the magnetic core.

[0005] Other embodiments of the present disclosure provide a structure including: a magnetic core having a length located within a pair of wiring layers of a device; and an inductor including a plurality of windings coupled together in series around the magnetic core, wherein at least one of the plurality of windings includes: a first segment located in a first wiring layer and extending across the width of the magnetic core; and a second segment located within a second wiring layer and coupled to the first segment by a vertical interconnect, wherein the second segment includes two sub-segments separated by a gap along the length of the magnetic core.

[0006] Additional embodiments of the present disclosure provide a method, including: providing an inductor including a plurality of windings coupled together in series around a magnetic core, wherein at least one of the plurality of windings includes: a first segment located in a first wiring layer and extending across the width of the magnetic core; and a second segment located within a second wiring layer and coupled to the first segment by a vertical interconnect, wherein the second segment includes two sub-segments separated by a gap along the length of the magnetic core; and passing a current through the inductor to induce a magnetic flux within the magnetic core, thereby inducing a flux density in a first portion of the magnetic core within the second segment of the winding that is less than a flux density in a second portion of the magnetic core within the first segment of the winding.

[0007] Two or more aspects described in the present disclosure, including the aspects described in the Summary of the Invention section, may be combined to form embodiments not specifically described herein.

[0008] Details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] These and other features of the present disclosure will be more readily understood from the following detailed description of aspects of the present disclosure, taken in conjunction with the accompanying drawings that illustrate various embodiments of the present disclosure, wherein:

[0010] Figure 1 A first top view of a structure according to an embodiment of the present disclosure is shown.

[0011] Figure 2 A plan view of a first segment and a second segment in a structure according to an embodiment of the present disclosure is shown.

[0012] Figure 3 A side view of a structure as viewed along line 3-3 according to an embodiment of the present disclosure is shown. Figure 1 from

[0013] Figure 4 A partial plan view of a first segment and a magnetic core in a structure according to an embodiment of the present disclosure is shown.

[0014] Figure 5 A partial plan view of a second segment and a magnetic core in a structure according to an embodiment of the present disclosure is shown.

[0015] Figure 6 A second plan view of a structure according to an additional embodiment of the present disclosure is shown.

[0016] Figure 7A plan view of a structure having an annotated magnetic field region during use in a method according to the present disclosure is shown.

[0017] Note that the drawings of the present disclosure are not necessarily drawn to scale. The drawings are intended to depict only typical aspects of the present disclosure and should not be regarded as limiting the scope of the present disclosure. In the drawings, like reference numerals represent like elements between the drawings. Detailed Description

[0018] In the following description, reference is made to the accompanying drawings which form a part hereof, and in which are shown, by way of illustration, specific exemplary embodiments in which the present teachings may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present teachings, it being understood that other embodiments may be used and changes may be made without departing from the scope of the present teachings. Accordingly, the following description is merely illustrative.

[0019] It will be understood that when an element such as a layer, region, or substrate is referred to as being “on” or “above” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” or “directly above” another element, no intervening elements are present. It should also be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, no intervening elements are present.

[0020] References in the specification to "one embodiment" or "an embodiment" of the present disclosure and other variations thereof mean that the specific features, structures, characteristics, etc. described in connection with that embodiment are included in at least one embodiment of the present disclosure. Thus, the phrases "in one embodiment" or "in an embodiment" and any other variations that occur throughout the specification do not necessarily all refer to the same embodiment. It should be understood that, for example, in the case of "A / B", "A and / or B", and "at least one of A and B", the use of any one of " / ", "and / or", and "at least one" is intended to include only the first-listed option (a), or only the second-listed option (B), or both options (A and B) being selected. As other examples, in the case of "A, B, and / or C" and "at least one of A, B, and C", these phrases are intended to include only the first-listed option (A), or only the second-listed option (B), or only the third-listed option (C), or only the first and second-listed options (A and B), or only the first and third-listed options (A and C), or only the second and third-listed options (B and C), or all three options (A and B and C) being selected. As will be apparent to those of ordinary skill in the art, this situation can be extended to many items listed.

[0021] The present disclosure provides a structure and method for an inductor that has a winding, with a first section of the winding connected to two second sections. The inductor according to the present disclosure includes a plurality of windings coupled together in series around a magnetic core. At least one of the plurality of windings includes a first section located in a first wiring layer and extending across the width of the magnetic core. The second section is located within a second wiring layer and is coupled to the first section by a vertical interconnect. The second section includes two sub-sections separated by a gap along the length of the magnetic core. Passing current through the inductor induces magnetic flux within the magnetic core. The winding intermittently divided into two or more sub-sections reduces the current density in certain parts of the inductor and similarly reduces the flux density in parts of the magnetic core adjacent to the sub-sections. Among other benefits, the structure of the present disclosure produces a smaller flux density within the magnetic core over a longer span of the magnetic core, thus accommodating a higher saturation current.

[0022] Figure 1Shows a first plan view of inductor 100, which can be integrated into an IC structure and / or various other microelectronic devices. Inductor 100 can surround a magnetic core 102, and magnetic core 102 can include any solid magnetic core material capable of being magnetized by the principle of inductance. Magnetic core 102 can be formed of one or more "soft magnetic materials", i.e., substances currently known or developed in the future that can exhibit a magnetic field in response to a relatively low amount of induced current in the wire thereon. Examples of materials suitable for use within magnetic core 102 include, but are not limited to: cobalt zirconium tantalum alloy, iron silicon alloy, nickel iron alloy, iron-containing (i.e., iron-based) materials such as "electron iron", steel, and soft ferrites, amorphous alloys, and nanocrystalline alloys, etc. Magnetic core 102 is shown by way of example as being substantially rectangular and near planar (i.e., having a negligible depth relative to length and width), but it should be understood that magnetic core 102 can have any of a variety of other shapes (e.g., cylindrical geometry, prismatic geometry, etc.).

[0023] Inductor 100 can include various sub-components formed of a conductive material (e.g., copper (Cu), aluminum (Al), and / or other materials suitable for use as a wire). During operation, the (one or more) conductive materials of inductor 100 will generate a magnetic field when subjected to an electric current to resist the increase and decrease of the current within the span of inductor 100. As described herein, inductor 100 can be subdivided into a plurality of individual windings 104, which together define a conductive loop within inductor 100. It should be emphasized that each winding 104 includes portions that enter and exit the page plane to define a plurality of conductive material loops, even if this is not directly visible from certain perspectives.

[0024] Inductor 100 includes a plurality of windings 104 coupled together in series around magnetic core 102. As described herein, some portions of each winding 104 can be interleaved with some portions of other windings 104 to utilize any available space around magnetic core 102. In addition, each winding 104 can be shaped to interleave with complementary shaped portions in another winding 104. Each of the windings 104 within inductor 100 can include a conductive material (e.g., copper (Cu), aluminum (Al), and / or other conductors discussed herein), and can be subdivided into segments of different shapes.

[0025] Now referring to Figure 1 and Figure 2 , each winding 104 of inductor 100 (only Figure 1)For example, it may include a first section 106 that extends transversely along a diagonal above the magnetic core 102. The first section 106 may be substantially planar and may be connected to other sections of the winding 104 by an interconnect 108 that extends vertically along the height of the magnetic core 102. The first section 106 may be located within a first wiring layer of the integrated circuit (IC) structure and may be located at a certain distance above the magnetic core 102 to prevent electrical short - circuit between the inductor 100 and the magnetic core 102. Similarly, the interconnect 108 may extend horizontally away from the magnetic core 102 to prevent electrical short - circuit between the interconnect 108 and the magnetic core 102.

[0026] Each winding 104 may also include a second section 110 that is connected in series to the first section 106 by an interconnect 108. One first section 106 and one second section 110 may together define a single "turn" of a winding 104 within the inductor 100. The second section 110 may include two sub - sections 111a, 111b. Each sub - section 111a, 111b may be located in a different wiring layer from the (one or more) first sections 106, but they may be located in the same vertically adjacent wiring layers of the device. Although each second section 110 (and its sub - sections 111a, 111b) of the winding 104 may be similar or even identical in size and shape, this is not necessary in all embodiments. The sub - sections 111a, 111b of the second section 110 may extend along a diagonal above the magnetic core 102 in a direction different from that of the (one or more) first sections 106 to which it is connected. As discussed in more detail herein, the orientations of the (one or more) first sections 106 and the second section 110 together define a generally V - shape in the X - Y plane. Each group of two or more sub - sections 111a, 111b may be coupled to one first section 106 by a corresponding interconnect 108. Additionally, the sub - sections 111a, 111b may be structurally continuous parts of the second section 110. The windings 104 may have similar or identical shapes, but they may also be in different positions. Thus, the first section 106 of one winding 104 will be interleaved with the second section 110 of another winding 104 (i.e., the first section 106 is located between the sub - sections 111a, 111b). The second sections 110 of the same winding will also be interleaved with the first section 106 of another winding 104.

[0027] For example, it may include a first section 106 that extends transversely along a diagonal above the magnetic core 102. The first section 106 may be substantially planar and may be connected to other sections of the winding 104 by an interconnect 108 that extends vertically along the height of the magnetic core 102. The first section 106 may be located within a first wiring layer of the integrated circuit (IC) structure and may be located at a certain distance above the magnetic core 102 to prevent electrical short - circuit between the inductor 100 and the magnetic core 102. Similarly, the interconnect 108 may extend horizontally away from the magnetic core 102 to prevent electrical short - circuit between the interconnect 108 and the magnetic core 102. Each winding 104 may also include a second section 110 that is connected in series to the first section 106 by an interconnect 108. One first section 106 and one second section 110 may together define a single "turn" of a winding 104 within the inductor 100. The second section 110 may include two sub - sections 111a, 111b. Each sub - section 111a, 111b may be located in a different wiring layer from the (one or more) first sections 106, but they may be located in the same vertically adjacent wiring layers of the device. Although each second section 110 (and its sub - sections 111a, 111b) of the winding 104 may be similar or even identical in size and shape, this is not necessary in all embodiments. The sub - sections 111a, 111b of the second section 110 may extend along a diagonal above the magnetic core 102 in a direction different from that of the (one or more) first sections 106 to which it is connected. As discussed in more detail herein, the orientations of the (one or more) first sections 106 and the second section 110 together define a generally V - shape in the X - Y plane. Each group of two or more sub - sections 111a, 111b may be coupled to one first section 106 by a corresponding interconnect 108. Additionally, the sub - sections 111a, 111b may be structurally continuous parts of the second section 110. The windings 104 may have similar or identical shapes, but they may also be in different positions. Thus, the first section 106 of one winding 104 will be interleaved with the second section 110 of another winding 104 (i.e., the first section 106 is located between the sub - sections 111a, 111b). The second sections 110 of the same winding will also be interleaved with the first section 106 of another winding 104.

[0028] The second segment 110 may have the shape of an annular basic parallelogram, with a hollow interior (i.e., the gap G between the sub-segments 111a, 111b). The annular shape of the second segment 110 allows the first segment 106 of another winding to be placed therein. In the second segment 110, each of the sub-segments 111a, 111b is defined as approximately one side or half of the conductive material of the second segment 110. In this case, the sub-segments 111a, 111b may be oriented parallel to each other within the device wiring layer in which they are formed. In this case, the portion of the second segment 110 in one winding 104 may horizontally surround the first segment(s) 106 of the other winding 104. The portions of the sub-segments 111a, 111b that extend across the width of the magnetic core 102 may be separated by the gap G along the length of the magnetic core 102. The gap G may have any size sufficient to prevent current from passing between the sub-segments 111a, 111b at locations other than the terminal(s) of the sub-segments 111a, 111b. In some cases, the gap G may be larger than the width of the first segment(s) 106 of the other winding 104 in the inductor 100. To provide for compact space utilization, the first segment(s) 106 of the other winding 104 may be located within the gap G between the two sub-segments 111a, 111b, but with sufficient horizontal spacing to prevent the first segment(s) 106 from being electrically shorted to the sub-segments 111a, 114b, or to prevent the sub-segments 111a, 114b from being electrically shorted to the first segment(s) 106.

[0029] During operation, the current flowing through a first segment 106 of the winding 104 is distributed across the sub-segments 111a, 111b of the second segment 110. The current in each of the sub-segments 111a, 111b of the second segment 110 is less than the total current transmitted through the first segment 106. Each first segment 106 of a winding 104 may be located in the same wiring layer of the IC structure, and each second segment 110 of the same winding 104 may be located in a different wiring layer, but may also be located in vertically adjacent wiring layers of the IC structure. When the inductor 100 includes multiple windings 104 around the magnetic core 102, one wiring layer may include the first segment 106 of one winding 104 that alternates with the second segment 110 of another winding 104 in the same wiring layer. Each winding 104 may include only the first segment 106 in one wiring layer and only the second segment 110 in another wiring layer. Figure 1An example of the first section 106 alternating with sub-sections 111a, 111b of the second section 110 on each side of the magnetic core 102 (i.e., in the same wiring layer) is shown. Each winding 104 of the inductor 100 may include one or more first sections 106, and the one or more first sections 106 are connected in series (e.g., through the interconnection 108) to the (one or more) second sections having sub-sections 111a, 111b, such that the windings 104 of the inductor 100 are staggered with respect to each other along the length of the magnetic core 102.

[0030] The interconnection 108 of the inductor 100 may serially couple the first section 106 to the second section 110. Figure 2 The interconnection 108 is shown in dashed lines in to indicate the coupling from one wiring layer to another wiring layer, and the other wiring layer is in a cross-section in front of or behind the plane shown in. To facilitate electrical communication and / or distribution between the sections 106, 110, the (one or more) interconnections 108 may be horizontally located between the magnetic core 102 and the longitudinal ends where the (one or more) sections 106, 110 appear. The (one or more) interconnections 108 in this position are particularly desirable when the sub-sections 111 in one wiring layer horizontally surround adjacent portions of the first section 106 in the same wiring layer. For example, thus the first section 106 does not physically contact the position where the sub-sections 111 are coupled together. In additional embodiments, the sections 106, 110 may be coupled by a greater number (e.g., two or more) of interconnections 108. Other numbers and arrangements of interconnections 108 are also possible. Figure 2 A side view of the inductor 100 from the angle of view line 3-3 is provided. It should be emphasized that in, the difference in shading indicates different windings 104, rather than different sections 106, 110. The inductor 100 as shown may be structurally integrated into other components of the device. The inductor 100 may be located above a substrate 120 (e.g., one or more semiconductor materials). The substrate 120 may include, but is not limited to, silicon, germanium, silicon germanium, silicon carbide, or any other common IC semiconductor or package substrate. A part or all of the entire semiconductor substrate 120 may be strained. The substrate 120 is shown as a bulk semiconductor layer, but this is not required in all embodiments. The substrate 120 may include various devices (e.g., transistors, capacitors, diodes, etc.) at other unshown positions thereon.

[0031] Figure 3 A view from Figure 1 is provided at an angle of view line 3-3 of the inductor 100. It should be emphasized that in Figure 3 , the difference in shading indicates different windings 104, rather than different sections 106, 110. The inductor 100 as shown may be structurally integrated into other components of the device. The inductor 100 may be located above a substrate 120 (e.g., one or more semiconductor materials). The substrate 120 may include, but is not limited to, silicon, germanium, silicon germanium, silicon carbide, or any other common IC semiconductor or package substrate. A part or all of the entire semiconductor substrate 120 may be strained. The substrate 120 is shown as a bulk semiconductor layer, but this is not required in all embodiments. The substrate 120 may include various devices (e.g., transistors, capacitors, diodes, etc.) at other unshown positions thereon.

[0032] The interlayer dielectric (ILD) layer 122 can be located on the substrate 120. The ILD layer 122 can include any currently known or later developed insulating material suitable for separating the various layers of the device from each other. For example, any material that is also suitable for use as trench isolation (TI) or for electrically separating the individual active semiconductor material regions within trench isolation (TI). Such materials can include, but are not limited to: silicon nitride (Si3N4), silicon dioxide (SiO2), fluorinated SiO2 (FSG), silicon carbon oxyhydride (SiCOH), porous SiCOH, borophosphosilicate glass (BPSG), silsesquioxane, carbon (C)-doped oxide (i.e., organosilicate) (which includes atoms of silicon (Si), carbon (C), oxygen (O), and / or hydrogen (H)), thermosetting polyarylether, spin-on silicon-carbon-containing polymer material, near-frictionless carbon (NFC), or layers thereof. However it is implemented, the ILD layer 122 can vertically separate the active material of the inductor 100 from other active materials located above or within the substrate 120 and / or other active or conductive components formed in the various metal wiring layers of the device.

[0033] The inductor 100 can be formed on the ILD layer 122, for example, by removing a portion of the material of the ILD layer 122 to a desired amount (e.g., by etching or other currently known or later developed processing techniques) and forming the inductor 100 and the magnetic core 102 on the remaining portion of the ILD layer 22. In the example shown, the second segment 110 and one or more of its sub-segments 111 can be formed within the ILD layer 122. The magnetic core 102 can be formed above the second segment 110 by reforming an insulating material above the second segment 110, and the interconnect(s) 108 can be formed on the second segment 110. In other cross-sections and / or embodiments, the first segment(s) 106 can be formed on the ILD layer 122 and can be adjacent to the second segment 110, as shown in other views herein.

[0034] The insulating liner 124 can be located on the ILD layer 122 and above the magnetic core 102 to vertically separate the ILD layer 122 from other ILD layers 122 formed above it. The insulating liner 124 can include a different type of insulator from the ILD layer(s) 122. For example, in the case where the ILD layer 122 includes an oxide insulator, the insulating liner 124 can include a nitride. During processing, the insulating liner(s) 124 can be used as an "etch stop layer" to control the location where certain wires, vias, etc. will be formed in the structure, such that the upper boundary of the device layer or the metal wiring layer above it can be defined. The insulating liner 124 and other materials above it (including the ILD layer 122) can define one wiring layer of the device (i.e., Figure 3layer "L1"). Other materials below the insulating liner 124 (including the ILD layer 122 therebelow) may define another wiring layer of the device (i.e., Figure 3 layer "L2"). The dashed line between the substrate 120 and the ILD layer 122 indicates that any desired number of device and / or wiring layers may be present between the substrate 120 and the layers L1, L2.

[0035] Portions of each winding 104 of the inductor 100 may be formed in different wiring layers. For example, the inductor 100 may be distributed above the device layer and the metal wiring layer thereabove, or may be distributed above two different metal wirings. Figure 3 An example of two metal wiring layers L1, L2 is shown, but the description herein applies equally to the inductor 100 formed in any combination of device layers and / or metal wiring layers, each having insulating material therein and / or therebetween. Figure 3 A side view of the inductor 100 is shown, rather than a cross-sectional view. Thus, the segments 106, 110, and some portions of each winding 104 may be located in different horizontal planes. Dashed lines appear in Figure 3 to indicate that some portions of the segments 106, 110 are horizontally located behind an overlapping portion of another segment 106, 110. During fabrication, after other portions of the inductor 100 are formed in the layer L2 below the wiring layer L1, the (one or more) first segments 106 of the inductor 100 may be formed in the wiring layer L1 on the (one or more) interconnects 108 and the insulating liner 124. In various other portions of the inductor 100 and / or other embodiments, the (one or more) second segments 110 and sub-segments 111 may be formed in the wiring layer L1, and the (one or more) first segments 106 may be formed in the wiring layer L2. The magnetic core 102 is shown in Figure 3 as being located within the wiring layer L2, but in additional embodiments, it may be located within the wiring layer L1 and / or any other wiring layer of the device. Wherever located, portions of the inductor 100 may be formed in the desired (one or more) wiring layers L1, L2, for example, by forming and etching repeated instances of the (one or more) ILD layers 122 and the (one or more) insulating liners 124. When the formation of one metal wiring layer (e.g., the wiring layer L2 including the ILD layer 122 and its insulating liner 124) is complete, the inductor 100 may not be complete.

[0036] Before forming an additional layer and / or insulating material over the insulating liner 124, the formation of each winding 104 in the inductor 100 can include forming (e.g., by deposition) additional conductive material in the form of a first segment 106 and / or an adjacent second segment 110 and its sub-segments 111. Thus, the segment(s) 106, 110 and / or sub-segment(s) 111 can be located in the ILD layer 122 of the wiring layer L1 such that they are on the upper surface of the insulating liner 124 and can physically interface with the upper surface of the vertical interconnect 108 formed through the insulating liner 124, but can be vertically away from the magnetic core 102. After forming the segments 106, 110 and the interconnect 108 therebetween, the inductor 100 defines a conductive path from one terminal to the other and can induce a magnetic field within the magnetic core 102 by operation. The formation of the segments 106, 110, sub-segments 111 and / or interconnect 108 can define the formation locations of the conductive metal and can include depositing metal and then planarizing (e.g., chemical mechanical planarization (CMP)) etc. Aspects of these processes can be controlled to provide varying widths and / or pitches in different parts of the inductor 100.

[0037] Reference Figure 4 and Figure 5 , the first segment 106 (only Figure 4 ) can be shaped to be interleaved along the length of the magnetic core 102 with the second segment 110 (only Figure 5 ) and its sub-segments 111a, 111b (only Figure 6 ). For ease of explanation and clarity of illustration, Figure 4 and Figure 5 both only show one of the two segments 106, 110. The first segment 106 can be substantially bridge-shaped, e.g., by extending diagonally across the width of the magnetic core 102 from one interconnect 108 to the other. Within the wiring layer L1 ( Figure 3 ), the middle portion of the first segment 106 can be substantially planar (i.e., it can have a negligible vertical thickness) and can extend linearly between the pairs of interconnects 108. Each interconnect 108 can connect one of a pair of first segments 106 to a sub-segment 111a, 111b of a second segment 110 below the magnetic core 102.

[0038] Figure 5 Shows the same wiring layer as the first segment 106 ( Figure 4 ), e.g., the wiring layer L1 ( Figure 3)) the second segment 110 of inductor 100. As described, the second segment 110 includes sub-segments 111a, 111b which together define a generally parallelogram-shaped geometry within the wiring layer L1. Thus, each second segment 110 does not extend linearly from one interconnect 108 to another, but forms an annular shape above the magnetic core 102 and within the wiring layer L1. The annular shape of each second segment 110 defines a gap G between the sub-segments 111a, 111b (only Figure 5 ). The location of the interconnect(s) 108 to the first segment 106 can be within the loop formed by the second segment 110, allowing the first segment(s) 106 to be placed within the gap G above the magnetic core 102. Thus, the first segment 106 can be staggered with and horizontally surrounded by adjacent second segments 1110 within the wiring layer L1. Among other advantages, this structural configuration also allows multiple windings 104 of the inductor 100 to be adjacent to each other within one wiring layer, but its size limits the current density within each segment. Compared to a conventional inductor, as shown, for example, a lower current density within the inductor 100 can be provided by subdividing the second segment 110 into sub-segments 111a, 111b and by interconnecting each second segment 110 via two first segments 106.

[0039] Reference Figure 7 , the staggering of the first segment 106 of the inductor 100 with the second segment 110 allows the size of the inductor 100 to be customized based on the length of the magnetic core 102. As shown, within multiple wiring layers of the device, the first segment 106 can be positioned horizontally adjacent to (and can be horizontally surrounded by) the staggered second segments 110. Additionally, the positions of the two first segments 106 on the vertical side of the magnetic core 102 can correspond to the position of one second segment 110 and its sub-segments 111a, 111b on the opposite side of the magnetic core 102. The generally V-shape formed by the different opposite orientations of each segment 106, 110 on the opposite sides of the magnetic core 102 allows the first segment 106 and the second segment 110 to alternate with each other along the length of the magnetic core 102, thereby providing a scalable inductor structure. For example, two second segments 110a, 110b, 110c, 110d are shown in the portion of the inductor 100 shown. Within one wiring layer above the magnetic core 102, two segments 110a, 110c alternate with the first segment 106. Within another wiring layer below the magnetic core 102, two other second segments 110b, 110d alternate with the first segment 106.

[0040] Figure 7A plan view of an integrated circuit (IC) structure 130 including an inductor 100 during operation is shown, where current is transmitted between opposite terminals T1, T2 of the inductor 100. Where applicable, terminals T1, T2 may be coupled to a current source and / or ground, and for ease of illustration only, Figure 7 the remaining components of the device are omitted. According to one example, terminal T1 is coupled to a current source and terminal T2 is coupled to ground such that current flows from terminal T1 to terminal T2. The inductor 100 constructed according to the present disclosure can be subdivided into five regions: a first region R1 at the connection with terminal T1, a second region R2 coupled to region R1 opposite terminal T1, a third region R3 coupled to region R2, a fourth region R4 coupled to region R3, and a fifth region R5 coupled between the fourth region R4 and terminal T2. Regions R1, R5 may each include only a portion of a first segment 106 and a second segment 110 of the inductor 100, as well as portions of the inductor 100 coupled to terminal T1 or T2, respectively. In addition, regions R2 and R4 may include portions of multiple first segments 106 and second segments 110, or in some cases, may include the entire first segment 106 and / or second segment 110. Region R5, which includes the center C of the magnetic core 102, may also include at least portions of multiple first segments 106 and second segments 110.

[0041] As described herein, the first segments 106 and second segments 110 of the inductor 100 may be interleaved, but may be shaped to distribute the current density over a larger physical space than may be possible in a conventional inductor. The increased current distribution may result from the presence of sub-segments 111a, 111b in the second segment 110 and the positioning of the first segment 106 within the space between the sub-segments 111a, 111b. During operation, the current through segments 106, 110 of the inductor 100 can produce a lower amount of magnetic flux (and thus a lower flux density) in the magnetic core 102 by distributing the current within the inductor 100 over a larger amount of material without increasing the "number of turns" relative to a conventional inductor. In a conventional inductor with "turns" of substantially uniform shape and thus similar dimensions or widths, the magnetic field strength (measured, for example, in amperes per meter (A / m)) may exceed 1500 A / m, or even be as high as 1900 A / m. These higher strength magnetic fields may occur at or near the center of a conventional inductor structure. Such high strength magnetic fields reduce the saturation (i.e., maximum allowable) current through the inductor, thereby limiting its technical applications.

[0042] The inductor 100 according to the present disclosure can be used for integration in an IC structure without exhibiting these unacceptably high magnetic field intensities. In an embodiment of the present disclosure, the peak magnetic field intensity can be in regions R2, R4 and can be at most about 1500 A / m, and more specifically can be between about 1300 A / m and about 1400 A / m. The relatively high magnetic field intensities in regions R2, R4 can result from there being less conductive material around the magnetic core 102 than in region R5 (where there are multiple portions of the plurality of segments 106, 110), and / or the distances of these regions from the terminals T1, T2. In regions R1, R3, R5, the magnetic field intensity is lower, ranging from about 700 A / m to about 1200 A / m. Thus, compared to the magnetic field intensities possible in conventional inductor structures that surround and / or rely on a magnetic core, the magnetic field intensities through regions R1 - R5 are more evenly distributed. These operational advantages result from the shape and / or staggering of the segments 106, 110 in each of the regions described herein and in turn can allow a greater amount of current to pass through the inductor 100 without saturating the current at an undesirably low magnitude. In contrast, the maximum saturation current of a conventional inductor structure is limited by the peak magnetic field intensity generated by its windings 104. Thus, the method according to the present disclosure includes providing an inductor 100 according to any embodiment herein and passing a current through the inductor 100 (e.g., from terminal T1 to terminal T2) to induce a magnetic flux within the magnetic core 102. The flux density in a first portion of the inductor 100 (e.g., region R2 or region R4 discussed herein) can be greater than the flux density in region R3 of the inductor 100, region R3 including the second segment(s) 110 and passing through the center C of the inductor 100.

[0043] Embodiments of the present disclosure provide various technical and commercial advantages, examples of which are discussed herein. Embodiments of the inductor 100 and / or the IC structure 130 ( Figure 7 ) allow the magnetic core 102 to be used in a product without limiting the maximum current of the inductor 100 before saturation. These benefits can be achieved using segments 106, 110 having different shapes (e.g., including sub - segments 111a, 111b in a loop) and without forming slits and / or air gaps within the inductor 100 or nearby components. As discussed herein, embodiments of the present disclosure can reduce the magnetic field density in a region of the inductor 100 passing through or near the center C by about 25% (otherwise, the magnetic field intensity would be highest here). This in turn results in a more even distribution of the magnetic field intensity through the magnetic core 102 during operation.

[0044] The methods and structures described above are used to fabricate integrated circuit chips. The resulting integrated circuit chips can be distributed by the manufacturer in the form of the original wafers (i.e., as a single wafer with multiple unpackaged chips), as bare die, or in a packaged form. In the latter case, the chips are mounted in the form of a single-chip package (e.g., a plastic carrier whose leads are fixed to a motherboard or other higher-level carrier) or a multi-chip package (e.g., a ceramic carrier having either or both surface interconnects or buried interconnects). In any case, the chips are then integrated with other chips, discrete circuit elements, and / or other signal processing devices as part of (a) an intermediate product (e.g., a motherboard) or (b) a final product. The final product can be any product that includes an integrated circuit chip, ranging from toys and other low-end applications to advanced computer products having a display, a keyboard, or other input devices, and a central processor.

[0045] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the disclosure. As used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It will be further understood that when the terms "comprises" and / or "comprising" are used in this specification, they specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. "Optional" or "optionally" means that the subsequent described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

[0046] Approximating language, as used throughout the specification and claims, may be applied to modify any quantitative representation that could permit variation without resulting in a change in the basic function to which it is related. Accordingly, values modified by one or more terms such as "about", "approximately", and "substantially" are not to be limited to the precise values specified. In at least some instances, the approximating language may correspond to the precision of the instrument used to measure the value. Throughout this specification and the claims which follow, ranges may be combined and / or interchanged, such ranges are identified and include all the sub-ranges contained therein unless the context or language indicates otherwise. The term "approximate" applied to a particular value of a range applies to both values of that range and may indicate, unless otherwise determined by the precision of the instrument measuring the value, + / - 10% of said value.

[0047] All of the corresponding structures, materials, acts, and equivalents of the means or step plus function elements in the following claims are intended to include any structures, materials, or acts that perform the functions in conjunction with other claimed elements specifically claimed. The description of the present disclosure has been given for purposes of illustration and description, but the description is not intended to be exhaustive or to limit the present disclosure to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the present disclosure. The embodiments were chosen and described in order to best explain the principles of the present disclosure and its practical application, and to enable others of ordinary skill in the art to understand the present disclosure with various embodiments having various modifications suitable for the particular purposes contemplated.

Claims

1. A structure, comprising: An inductor, which includes a plurality of windings coupled together in series around a magnetic core, wherein at least one of the plurality of windings includes: A first segment, which is located in a first wiring layer and extends across the width of the magnetic core, and A second segment, which is located within a second wiring layer and is coupled to the first segment through a vertical interconnect, wherein the second segment includes two sub - segments separated by a gap along the length of the magnetic core.

2. The structure according to claim 1, wherein, The orientation of the first segment and the orientation of the second segment together define a substantially V - shape.

3. The structure according to claim 1, wherein The two sub - segments of the second segment are oriented parallel to each other within the second wiring layer.

4. The structure according to claim 1, wherein, A portion of the first segment of another winding of the inductor is located within the gap between the two sub - segments of the second segment.

5. The structure according to claim 1, wherein, The second segment horizontally surrounds the first segment of another winding of the inductor.

6. The structure according to claim 1, wherein, Each of the plurality of windings of the inductor includes the first segment and the second segment having the two sub - segments, and each of the corresponding vertical interconnects is located between the magnetic core and a longitudinal end of the first segment.

7. The structure according to claim 1, wherein, Each of the plurality of windings of the inductor includes the first segment and the second segment having the two sub - segments, and each winding of the inductor is staggered with another winding along the length of the magnetic core.

8. A structure, comprising: A magnetic core, which has a length located within a pair of wiring layers of a device; And An inductor, which includes a plurality of windings coupled together in series around the magnetic core, wherein at least one of the plurality of windings includes: A first segment, which is located in a first wiring layer and extends across the width of the magnetic core, and A second segment, which is located within a second wiring layer and is coupled to the first segment through a vertical interconnect, wherein the second segment includes two sub - segments separated by a gap along the length of the magnetic core.

9. The structure according to claim 8, wherein, The orientation of the first segment and the orientation of the second segment together define a substantially V - shape.

10. The structure according to claim 8, wherein, The two sub - segments of the second segment are oriented parallel to each other within the second wiring layer.

11. The structure according to claim 8, wherein, The second segment horizontally surrounds the first segment of another winding of the inductor.

12. The structure according to claim 8, wherein Each of the plurality of windings of the inductor includes the first segment and the second segment having the two sub - segments, and each of the corresponding vertical interconnects is located between the magnetic core and a longitudinal end of the first segment.

13. The structure according to claim 8, wherein Each of the plurality of windings of the inductor includes the first segment and the second segment having the two sub - segments.

14. The structure according to claim 13, wherein, Each winding of the inductor is staggered with a corresponding adjacent winding along the length of the magnetic core.

15. A method, comprising: Providing an inductor, which includes a plurality of windings coupled together in series around a magnetic core, wherein at least one of the plurality of windings includes: A first segment, which is located in a first wiring layer and extends across the width of the magnetic core, and A second section, which is located within the second wiring layer and is coupled to the first section by a vertical interconnection, wherein the second section includes two sub-sections separated by a gap along the length of the magnetic core; and A current is transmitted through the inductor to induce a magnetic flux within the magnetic core, thereby inducing a flux density in a first portion of the magnetic core within the second section of the winding that is smaller than the flux density in a second portion of the magnetic core within the first section of the winding.

16. The method according to claim 15, wherein, Each winding of the plurality of windings of the inductor includes the first section and the second section having the two sub-sections, and each vertical interconnection of the corresponding vertical interconnections is located between the magnetic core and a longitudinal end of the first section.

17. The method according to claim 15, wherein The two sub-sections are oriented parallel to each other within the second wiring layer.

18. The method according to claim 15, wherein, A portion of the first section of another winding of the inductor is located within the gap between the two sub-sections.

19. The method according to claim 15, wherein, The second section horizontally surrounds the first section of another winding of the inductor.

20. The method according to claim 15, wherein Each winding of the plurality of windings of the inductor includes the first section and the second section having the two sub-sections, and each winding of the inductor is staggered with another winding along the length of the magnetic core.

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