The present disclosure relates generally to microelectronic devices, and more particularly to capacitors in microelectronic devices.
A capacitor is a passive electronic component that stores electrical energy in an electric field, by accumulating electric charges on two opposing electrodes separated by dielectric material. Capacitors are widely used in various types of circuits, and for a wide range of applications, such as filtering signals, storing energy, conditioning a power signal, many other applications.
The figures depict various embodiments of the present disclosure for purposes of illustration only and are not necessarily drawn to scale. Numerous variations, configurations, and other embodiments will be apparent from the following detailed discussion.
Disclosed herein are capacitor structures that are integrated with contact pad structures. For example, instead of using a separate surface mounted capacitor, the capacitor is integrated with two or more contact pads. Such an integrated capacitor structure may be formed at a die level, at a package level, or at a circuit board level.
In one embodiment, a microelectronic device comprises a first contact pad structure including conductive material, and a first horizontal portion of conductive material extending from the first contact pad structure along a first horizontal plane. The microelectronic device further comprises a second contact pad structure including conductive material, and a second horizontal portion of conductive material extending from the second contact pad structure along a second horizontal plane different from the first horizontal plane. A dielectric material is between the first horizontal plane and the second first horizontal plane (so as to also be between the first and second horizontal portions of conductive material). In an example, the dielectric material is a layer of dielectric material and has a thickness of at most 4000 nanometers (nm). More generally, the dielectric thickness (or distance between the first and second horizontal portions of conductive material) may be any distance suitable for providing a desired capacitance for a given application. In an example, at least a section of the first horizontal portion provides a first capacitor electrode, at least a section of the second horizontal portion provides a second capacitor electrode, and at least a section of the layer of dielectric material provides a capacitor dielectric, where the first capacitor electrode, the second capacitor electrode, and the capacitor dielectric provide a capacitor. Each of the first and second horizontal portions of conductive material may extend horizontally in a discontinuous fashion, such that there may be one or more openings in that horizontal portion.
In another embodiment, an interconnect structure comprises a first layer of conductive material comprising (i) a first vertical portion, and (ii) a first horizontal portion extending along a first horizontal plane, with a first opening within the first horizontal portion. The interconnect structure further comprises a second layer of conductive material comprising (i) a second vertical portion, and (ii) a second horizontal portion extending along a second horizontal plane, with a second opening within the second horizontal portion. A layer of dielectric material extends along a third horizontal plane between the first and second horizontal portions, and has third and fourth openings. In an example, the first vertical component extends upward from the first horizontal portion, through the third opening within the layer of dielectric material and through the second opening within the second horizontal portion. Also, in this example, the second vertical component extends downward from the second horizontal portion, through the fourth opening within the layer of dielectric material and through the first opening within the first horizontal portion. In such an example, at least a section of the first horizontal portion provides a first capacitor electrode, at least a section of the second horizontal portion provides a second capacitor electrode, and at least a section of the layer of dielectric material provides a capacitor dielectric, wherein the first capacitor electrode, the second capacitor electrode, and the capacitor dielectric provide a capacitor or an otherwise intentionally capacitive structure. In some such examples, a first interconnect component is coupled to an upper surface of the first vertical portion, and a second interconnect component is coupled to an upper surface of the second horizontal portion. The first and second interconnect components may be, for instance, a conductive bump such as a solder ball or other similar conductive interconnect feature (e.g., any bump-like feature of metal, alloy or other conductive material). In an example, the interconnect structure is included within one of a printed circuit or wiring board (PCB or PWB), an integrated circuit die, or a carrier substrate of an integrated circuit package.
In yet another embodiment, a capacitor structure comprises a first electrode, continuous and monolithic with, a first contact pad; a second electrode, continuous and monolithic with, a second contact pad; and a capacitor dielectric between the first electrode and the second electrode. In an example, the first contact pad comprises a vertical structure that extends through an opening within the second electrode, without making contact with the second electrode. Numerous variations and embodiments will be apparent in light of the present disclosure.
As indicated above, capacitors may be mounted on a surface of a circuit board, or a surface of an integrated circuit package carrier substrate. However, such surface mount capacitors may consume a significant amount of space in a microelectronic device package or a circuit board, such as a printed wiring board (PWB), a printed circuit board (PCB), or a circuit card assembly (CCA).
Accordingly, techniques are described herein to form capacitors that are integrated with contact pad structures of a microelectronics device. For example, instead of using a separate surface mount capacitor, the capacitor is integrated with the contact pad structure itself, thereby saving area to implement the capacitor, as well as enhancing performance, as will be described below in detail.
In some examples, in an interconnect structure of a microelectronics device structure, a first contact pad may be implemented using a first layer of conductive material, and a second contact pad may be implemented using a second layer of conductive material. In some such examples, the first layer comprises (i) a first horizontal portion extending along a first horizontal plane, with a first plurality of openings within the first horizontal portion, and (ii) one or more first vertical portions. Similarly, the second layer comprises (i) a second horizontal portion extending along a second horizontal plane, with a second plurality of openings within the second horizontal portion, and (ii) one or more second vertical portions. A dielectric material extends along a third horizontal plane between the first and second horizontal planes, such that the dielectric material is between the first and second horizontal portions. For example, a layer of dielectric material is above the second horizontal portion, and the first horizontal portion is above the layer of dielectric material.
In one such embodiment, the layer of dielectric material has a third plurality of openings. Each of the third plurality of openings may be aligned with (e.g., above or below) one of the first plurality of openings of the first layer and/or one of the second plurality of openings of the second layer.
In one embodiment and as will be described in detail below, at least one of the first vertical portions of the first layer extends upward from the first horizontal portion, through an opening within the dielectric material and through an opening within the second horizontal portion (e.g., without contacting the second horizontal portion). Similarly, at least one of the second vertical portions of the second layer extends downward from the second horizontal portion, through another opening within the dielectric material and through an opening within the first horizontal portion (e.g., without contacting the first horizontal portion).
In one embodiment, a first contact pad is formed by at least a section of an upper surface of the at least one of the first vertical portions of the first layer. For example, an interconnect component (e.g., a conductive bump, such as a solder ball) is coupled to the first contact pad.
In one embodiment, a second contact pad is formed by at least a section of an upper surface of the second horizontal portion of the second layer. For example, another interconnect component (e.g., a conductive bump, such as a solder ball) is coupled to the second contact pad.
In one embodiment, at least a section of the first horizontal portion provides a first capacitor electrode, at least a section of the second horizontal portion provides a second capacitor electrode, and at least a section of the layer of dielectric material provides a capacitor dielectric, wherein the first capacitor electrode, the second capacitor electrode, and the capacitor dielectric provide a capacitor. Thus, the capacitor is formed using conductive electrodes that are lateral extensions (e.g., two horizontal portions of the two layers) of the two corresponding contact pads described above.
In one example, a third conductive layer may extend vertically through openings within the first horizontal portion, the second horizontal portion, and the layer of dielectric material, without contacting the first or second horizontal portions. In such an example, an upper surface of the third layer may form a third contact pad, and may be coupled to a third interconnect component (e.g., a conductive bump, such as a solder ball).
In an example, the first horizontal section of the first layer may be a first one of a power plane, a ground plane, or a signal plane. The second horizontal section of the second layer may be a second one of the power plane, the ground plane, or the signal plane. The third vertical layer may be a third one of the power plane, the ground plane, or the signal plane.
The capacitor that is formed using the horizontal portions of the first and second layers may be implemented at any level of an integrated circuit system. For example, the first and second layers (sections of which form the contact pads and the capacitor) can be on an integrated circuit die, e.g., to couple the die in a flip-chip configuration to a package carrier substrate through corresponding solder bumps. In another example, the first and second layers (sections of which form the contact pads and the capacitor) can be on the package carrier substrate, e.g., to couple the package carrier substrate through corresponding solder bumps to the die, or a PCB. In another example, the first and second layers (sections of which form the contact pads and the capacitor) can be on the package carrier substrate, e.g., to couple the package carrier substrate through corresponding solder balls to a circuit board such as a PCB. In yet another example, the first and second layers (sections of which form the contact pads and the capacitor) can be on the circuit board, e.g., to couple the circuit board through corresponding solder balls to the package carrier substrate. Thus, in an example, the integrated capacitor may be at a die level, at a package level, or a board level. In an example, a device (such as a die, a package carrier substrate, or a circuit board) includes the above described contact pads and the capacitor integrated therewith.
Thus, the above described capacitor utilizes the first and second layers coupled to the contact pads, and is integrated with these contact pads. The capacitor is formed without taking substantial space within the microelectronic device structure. For example, there may not be an area penalty in the X-Y plane due to the formation of the capacitor, as the first and second layers would be anyway formed for the contact pads. There may be an increase in the vertical height of the microelectronic device structure, due to formation of the capacitor, where such an increase in the height may be equal to a height or thickness of the layer of dielectric material, and a height or thickness of any of the first or second horizontal portions. However, such an increase in height may be negligible, e.g., due to a relatively small thickness (or vertical height) of the first and second horizontal portions and the dielectric material. For example, the layer of dielectric material may have a thickness (e.g., measured in the vertical or Z-axis direction) in the range of 100 nanometers (nm) to 4000 nm, and may depend on a desired dielectric constant of the capacitor dielectric material. For example, with aluminum nitride as the capacitor dielectric material (e.g., having a dielectric constant of about 8.5), a capacitor with about 75 pF/mm2 may be achieved with a vertical thickness of about 1020 nm of the dielectric material. In an example, the vertical thickness of the first and/or second horizontal portions may be in the range of 10 nm to 500 nm.
In one embodiment, the capacitor integrated with the contact pads eliminates or at least reduces usage of surface or board mount capacitors, thereby saving area, cost, and/or performance of the microelectronic device structure. In an example where the capacitor is used for power conditioning, integrating the capacitor with the contact pads and having the capacitor proximal to the power and ground planes may reduce parasitic inductance, which increases effective capacitance at high frequencies, e.g., resulting in enhanced performance of high-speed integrated circuits.
In one embodiment, each of the first and second layers may be additively formed. For example, the first horizontal portion and the first vertical portions of the first layer may be formed during a same deposition process, and hence, the first layer may be continuous and monolithic, e.g., without any interface (e.g., a seam or a grain boundary) therebetween. Similarly, the second layer may also be continuous and monolithic. Further processes to form the first and second layers and the capacitor are described below, e.g., with respect to
In accordance with some embodiments of the present disclosure, these various approaches can be used individually or together to design and form capacitors integrated with conductive contact pads. Numerous variations and embodiments will be apparent in light of the present disclosure.
As used herein, the term “about” indicates that the value listed may be somewhat altered or otherwise within an acceptable tolerance, as long as the alteration does not result in nonconformance of the process or device. For example, for some elements the term “about” can refer to a variation of +0.1%, for other elements, the term “about” can refer to a variation of ±1% or ±10%, or any point therein. As also used herein, terms defined in the singular are intended to include those terms defined in the plural and vice versa.
Reference herein to any numerical range expressly includes each numerical value (including fractional numbers and whole numbers) encompassed by that range. To illustrate, reference herein to a range of “at least 50” or “at least about 50” includes whole numbers of 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, etc., and fractional numbers 50.1, 50.2 50.3, 50.4, 50.5, 50.6, 50.7, 50.8, 50.9, etc. In a further illustration, reference herein to a range of “less than 50” or “less than about 50” includes whole numbers 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, etc., and fractional numbers 49.9, 49.8, 49.7, 49.6, 49.5, 49.4, 49.3, 49.2, 49.1, 49.0, etc.
As used herein, the term “substantially”, or “substantial”, is equally applicable when used in a negative connotation to refer to the complete or near complete lack of an action, characteristic, property, state, structure, item, or result. For example, a surface that is “substantially” flat would either completely flat, or so nearly flat that the effect would be the same as if it were completely flat.
As described below, in an example, the structure 100 comprises an interconnect structure 101 above a device 150, where the device 150 may be a printed circuit board (PCB), a printed wiring board (PWB), a package substrate, an integrated circuit die, or another appropriate integrated circuit device. Thus, the structure 100, including the interconnect structure 101, may be implemented at a board level, at a package level, or a die level of a microelectronic device system. Note that the device 150 is illustrated in
Referring to
In some examples, the horizontal portion 109 and the vertical portions 111 may form the continuous conductive material of the layer 107. In some such examples, the layer 107 may be monolithic. For example, there may not be an interface (such as seam or grain boundary) between the horizontal portion 109 and the vertical portions 111 of the layer 107; instead, they are part of the same continuous body of conductive material. For example, the layer 107, including the horizontal portion 109 and the vertical portions 111, may be formed using a same conductive material deposition process (e.g., formed using an additive deposition process), and hence, the layer 107 may be continuous and monolithic. However, in another example, the horizontal portion 109 and the vertical portions 111 may be formed by separate conductive material deposition process, and there may be an interface therebetween.
Note that the intersection between the horizontal portion 109 and the vertical portion 111a illustrated in
In one embodiment, the layer 107 may comprise an appropriate conductive material, such as one or more metals and/or alloys thereof. For example, the layer 107 may comprise copper, aluminum, nickel, gold, silver, and/or another appropriate conductive material.
The layer 107 has a plurality of openings 126a, 126b, 126c therewithin. The openings 126 are within the horizontal portion 109 of the layer 107. Although three openings 126a, 126b, 126c of the layer 107 are illustrated in
The interconnect structure 101 further comprises a layer 117 of conductive material. In an example, the layer 117 comprises a horizontal portion 119 extending along the horizontal plane (e.g., along the plane defined by the X-Y axes), and one or more (such as a plurality of) vertical portions 121 extending vertically upward (e.g., along the Z-axis direction) from the horizontal portion 119. Note that in
Note that the intersection between the horizontal portion 119 and the vertical portion 121a illustrated in
In some examples, the horizontal portion 119 and the vertical portions 121 may form the continuous conductive material of the layer 117. In some such examples, the layer 117 may be monolithic. For example, there may not be an interface (such as seam or grain boundary) between the horizontal portion 119 and the vertical portions 121 of the layer 117; instead, they are part of the same continuous body of conductive material. For example, the layer 117, including the horizontal portion 119 and the vertical portions 121, may be formed using a same conductive material deposition process (e.g., formed using an additive deposition process), and hence, the layer 117 may be continuous and monolithic. However, in another example, the horizontal portion 119 and the vertical portions 121 may be formed by separate conductive material deposition process, and there may be an interface therebetween.
In one embodiment, the layer 117 may comprise an appropriate conductive material, such as one or more metals and/or alloys thereof. For example, the layer 117 may comprise copper, aluminum, nickel, gold, silver, and/or another appropriate conductive material.
In an example, the layers 107 and 117 may be compositionally the same, or different. In an example, the layers 107 and 117 may be elementally the same, or different.
The layer 117 has a plurality of openings 125a, 125b therewithin. The openings 125 are within the horizontal portion 119 of the layer 117. Although two openings 125a, 125b of the layer 117 are illustrated in
As illustrated in
The dielectric material 130 may be any appropriate dielectric material, such as one or more appropriate oxides, nitrides, carbides, oxynitrides, oxycarbides, and/or oxycarbonitrides. Examples of the dielectric material 130 include aluminum oxide (Al2O3), aluminum nitride (AlN), silicon oxide (SiO2), tungsten trioxide (WO3), titanium dioxide (TiO2), and/or another appropriate dielectric material. In an example and as described below, the dielectric material 130 forms a dielectric material of a capacitor, and a choice of the dielectric material 130 may be based on a desired dielectric constant of the dielectric material 130.
In one embodiment, the dielectric material 130 also has a plurality of openings 132a, 132b, 132c, 132d. Although four openings 132 are illustrated within the dielectric material 130, the dielectric material 130 may include a greater number of openings, in an example.
In one embodiment, each opening 132 of the dielectric material 130 is at least in part aligned with one or more other openings of the layers 107 and/or 117. For example, as illustrated in
In one embodiment, each of the vertical portions 111 and 121 of the layers 107, 117, respectively, extends through one or more of the above described openings. For example, as illustrated in
In one embodiment, the interconnect structure 101 also comprises a plurality of layers or vertical components 127 extending through openings of the dielectric material 130 and the layers 107, 117, although only one such example vertical component 127a is illustrated in
In one embodiment, the interconnect structure 101 comprises a plurality of interconnect components 140a, 140b, 140c, 140d. The interconnect components 140a, 140b, 140c, 140d may be, for example, solder balls, solder bumps, or other appropriate interconnect components. In one embodiment, the interconnect components 140a, 140b, 140c, 140d couple the device 150 to a circuit outside the structure 100, where the outside circuit can be a printed circuit board (PCB), printed wiring board (PWB), a package substrate, or an integrated circuit die, for example.
In one embodiment, the layers 107, 117, 127 of the interconnect structure 101 are formed on the device 150 of the structure 100. The device 150 may comprise a PCB, PWB, a package substrate, or an integrated circuit die, for example, depending on whether the interconnect structure 101 is implemented at a die level, or a package level, or a board level, as described below (e.g., see
In one embodiment, as labelled in
Similarly, a contact pad 106 comprises at least a section of the upper surface of the horizontal portion 109 of the layer 107 (or at least a section of an upper surface of the vertical portion 111a, e.g., depending on whether the intersection between the horizontal portion 109 and the vertical portion 111a is considered to be a part of the horizontal portion 109 or the vertical portion 111a, as described above). The interconnect component 140d is on the contact pad 106.
Thus, the horizontal portion 119 of the layer 117 extends laterally from the contact pads 104a, 104b. Similarly, the horizontal portion 109 of the layer 107 extends laterally from the contact pad 104d. As described above, the horizontal portion 109 is above the horizontal portion 119, and separated from the horizontal portion 119 by the dielectric material 130.
In one embodiment, at least a section of the horizontal portion 109 comprises a first electrode of a capacitor 142, at least a section of the horizontal portion 119 comprises a second electrode of the capacitor 142, and the dielectric material 130 comprises a capacitor dielectric, as labelled in
The capacitor 142 utilizes the layers 107, 119 coupled to the contact pads 104a, 104b, 106, and is integrated with these contact pads. Thus, the capacitor 142 is formed without taking substantial space within the structure 100. For example, there may not be an area penalty in the X-Y plane due to the formation of the capacitor 142, as the layers 107, 117 would be anyway formed for the contact pads 104, 105, 106. There may be an increase in the vertical height of the structure 100 due to formation of the capacitor 142, where such an increase in the height may be equal to a height of the dielectric material 130 and a height of any of the horizontal portions 109 or 119. However, such an increase in height may be negligible, e.g., due to a relatively small thickness (or vertical height) of the horizontal portions 109 or 119 and the dielectric material 130.
The capacitor 142 integrated with the contact pads 104a, 104b, 106 eliminates or at least reduces usage of surface or board mount capacitors, thereby saving area, cost, and/or performance of the structure 100. In an example where the capacitor 142 is used for power conditioning, locating the capacitor 142 on the interconnect structure 101 reduces parasitic inductance, which increases effective capacitance at high frequencies, e.g., resulting in enhanced performance of high-speed integrated circuits.
In one embodiment, the dielectric material 130 may have a thickness (e.g., measured in the vertical or Z-axis direction) in the range of 100 nanometers (nm) to 4000 nm, and may depend on a desired dielectric constant of the capacitor dielectric material. For example, with aluminum nitride as the capacitor dielectric material 130 (e.g., having a dielectric constant of about 8.5), a capacitor with about 75 pF/mm2 may be achieved with a vertical thickness of about 1020 nm of the dielectric material 130.
In one embodiment, the layers 107, 117, 127 may be used to transmit power, ground, and/or signals. In an example, the layer 117 may be used to transmit power, the layer 107 may be used for grounding, and the layer 127a may be used to transmit signals. In another example, the layer 117 may be used for grounding, the layer 107 may be used to transmit power, and the layer 127a may be used to transmit signals. Other combinations may also be possible. In an example where the layer 127a is used to transmit signals, signal transmission is unaffected by the capacitor 142 formed between the ground plane and the power plane.
In an example, there may be multiple interconnect components 140 for the ground connection, and multiple interconnect components 140 for the power connection. Accordingly, the layer 117 may have more than one vertical portions (such as vertical portions 121a, 121b) to receive the interconnect components 140a, 140b. Similarly, the layer 107 may have more than one vertical portions (although only one vertical portion 111a is illustrated in
In
In one embodiment, multiple such capacitors may be formed and integrated with the contact pads of the structure 100. For example,
For example, comparing the structure 300 of
The conductive layer 107 has a horizontal section 109 and the conductive layer 307 has a horizontal section 309. Each of the conductive layers 107 and 307 have corresponding one or more vertical portions that are similar to the vertical portion 111 of
Similar to
In an example, the layer 107 of
In another example, instead of (or in addition to) splitting the layer 107 of
For example, in
Similarly, for example, in
Thus, a first capacitor may be formed between horizontal portions 109a and 119a, separated by a corresponding layer of dielectric material 130. Similarly, a second capacitor may be formed between horizontal portions 119a and 109b, separated by a corresponding layer of dielectric material 130, and so on. Thus, depending on a number of layers, more than one capacitor may be formed in the structure 400.
Referring to
As illustrated, each of the interconnect components 512 is coupled to the die 504 through a corresponding contact pad 516, and is coupled to the carrier substrate 508 through a corresponding contact pad 517. Thus, there are a plurality of contact pads 516 coupled to the die 504, and another plurality of contact pads 517 coupled to the carrier substrate 508.
In one embodiment, at least some of the contact pads 516 are integrated with one or more capacitors described above with respect to
Similarly, in one embodiment, at least some of the pads 517 are integrated with one or more capacitors described above with respect to
As illustrated in
In one embodiment, at least some of the contact pads 518 are integrated with one or more capacitors described above with respect to
Similarly, in one embodiment, at least some of the pads 519 are integrated with one or more capacitors described above with respect to
Thus, in an example, the device 150 of
The integrated circuit system 550 comprises a wire bonded integrated circuit package, in which an integrated circuit chip or die 554 is arranged in a wire bonded configuration on a carrier substrate 558. As illustrated, the die 554 is coupled to the carrier substrate 558 through a plurality of conductive wires 560. In an example, each wire 560 is coupled to the die 554 through a corresponding contact pad structure 566, and to the carrier substrate 558 through a corresponding contact pad structure 569. Thus, there are a plurality of contact pad structures 566 coupled to the die 554, and another plurality of contact pad structures 569 coupled to the carrier substrate 558, in an example.
In one embodiment, at least some of the contact pad structures 566 are similar to the contact pad structures described above with respect to
Referring to
The method 600 proceeds from 604 to 608, where a layer of dielectric material 130 is formed above the horizontal portion 119 of the layer 117, where the dielectric material 130 has openings 132a, 132b, 132c, 132d, e.g., as illustrated in
The method 600 proceeds from 608 to 612, where the upper layer 107 is formed, where the layer 107 comprises horizontal portion 109, vertical portion 111a, and openings 126a, 126b, 126c extending within the horizontal portion 109, as illustrated in
The method 600 proceeds from 612 to 616, where the interconnect components 104a, 104b, 104c, 104d are couped (e.g., soldered, or otherwise coupled) to the structure 700 as illustrated in
Note that the processes in method 600 are shown in a particular order for ease of description. However, one or more of the processes may be performed in a different order or may not be performed at all (and thus be optional), in accordance with some embodiments. Numerous variations on method 600 and the techniques described herein will be apparent in light of this disclosure.
The following examples pertain to further embodiments, from which numerous permutations and configurations will be apparent.
The foregoing description of example embodiments has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed. Many modifications and variations are possible in light of this disclosure. It is intended that the scope of the present disclosure be limited not by this detailed description, but rather by the claims appended hereto. Future-filed applications claiming priority to this application may claim the disclosed subject matter in a different manner and generally may include any set of one or more limitations as variously disclosed or otherwise demonstrated herein.