Patent ID: 12228538

In accordance with common practice, the features depicted by the drawings may not be drawn to scale. Accordingly, the dimensions of the depicted features may be arbitrarily expanded or reduced for clarity. In accordance with common practice, some of the drawings are simplified for clarity. Thus, the drawings may not depict all components of a particular apparatus or method. Further, like reference numerals denote like features throughout the specification and figures.

DETAILED DESCRIPTION

Aspects of the present disclosure are illustrated in the following description and related drawings directed to specific embodiments. Alternate aspects or embodiments may be devised without departing from the scope of the teachings herein. Additionally, well-known elements of the illustrative embodiments herein may not be described in detail or may be omitted so as not to obscure the relevant details of the teachings in the present disclosure.

In certain described example implementations, instances are identified where various component structures and portions of operations can be taken from known, conventional techniques, and then arranged in accordance with one or more exemplary embodiments. In such instances, internal details of the known, conventional component structures and/or portions of operations may be omitted to help avoid potential obfuscation of the concepts illustrated in the illustrative embodiments disclosed herein.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting As used herein, the singular forms “a.” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including.” when used herein, specify the presence of 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. It will also be understood that when a layer is described as “over,” “overlying,” “under,” “underlying,” another layer does not necessarily preclude the use of intermediate layers and/or materials that may otherwise be used to ensure adhesion between the layers.

In order to fully illustrate aspects of the design of the present disclosure, methods of fabrication are presented. Other methods of fabrication are possible, and discussed fabrication methods are presented only to aid understanding of the concepts disclosed herein.

Certain aspects of the disclosure are directed to moisture sensing devices formed as an integrated circuit structure. In an aspect, such moisture sensing devices may be manufactured as individual moisture sensing devices that are subsequently surface mounted to a substrate for connection with other electronic components. In an aspect, such moisture sensing devices may be manufactured in the same substrate as the other electronic components. As will be understood, various electrical connection relationships may exist between the moisture sensing devices and the other electronic components.

FIGS.1A,1B, and1C(collectivelyFIG.1) depicts various views of an example moisture sensor100, according to aspects of the disclosure.FIG.1Ais a top cutaway view of the moisture sensor100.FIG.1Bis a cross-sectional view of the moisture sensor100taken along line1B-1B ofFIG.1A, whileFIG.1Cis a cross-sectional view of the moisture sensor100taken along line1C-1C.

As shown inFIG.1, the moisture sensor100includes a patterned refractory metal layer102formed from a refractory metal (e.g., tungsten, tungsten alloy, tantalum, tantalum alloy, niobium, niobium alloy, rhenium, rhenium allow, etc.). The patterned refractory metal layer102may be deposited or otherwise formed on a substrate104, such as a silicon dioxide (SiO2) or silicon nitride (SiN) substrate. As will be set forth in more detail below, the patterned refractory metal layer102metal may serve a dual function. In an aspect, the patterned refractory metal layer102may form a plate of a capacitor as well as serve as a heating element for controlling the temperature of the moisture sensor100. InFIG.1, a dielectric material, such as SiO2or SiN, may be deposited or otherwise formed to fill the interstitial regions between the traces of the patterned refractory metal layer102.

In an aspect, a dielectric layer106formed from a moisture-insensitive dielectric material overlies the patterned refractory metal layer102. The dielectric layer106shown inFIG.1may be formed with the same dielectric material as the substrate104. In an aspect, the dielectric material used to form the dielectric layer106may be a moisture-insensitive material (e.g., SiO2or SiN) in that the dielectric value of the dielectric material does not substantially vary in the presence of moisture.

In an aspect, a patterned metal layer108overlies the dielectric layer106. The patterned metal layer108may be formed from a conductive material, such as copper, aluminum, etc. Together, the patterned refractory metal layer102, dielectric layer106, and the patterned metal layer108form a capacitor110, shown in schematic format inFIG.1. In this example, the capacitor110is formed to have a fixed capacitance value, at least in the sense that the capacitance value does not vary significantly in the presence of moisture. InFIG.1, a dielectric material, such as SiO2or SiN, may be deposited or otherwise formed to fill the interstitial regions between the traces of the patterned metal layer108.

In an aspect, a further dielectric layer112is disposed over the patterned metal layer108. In this example, the dielectric layer112is formed from a moisture-sensitive dielectric material having a low dielectric constant (low-K) or extremely low dielectric constant (ELK). In an aspect, the low-K and/or ELK dielectric material may have a small dielectric constant relative to other dielectric materials (e.g., SiO2, SiN, ceramics, mica, etc.) used in manufacturing integrated devices. In an aspect, the dielectric constant of such moisture-sensitive dielectric may have a dielectric value below 4.3, and often below 3.0. In an aspect, the moisture-sensitive dielectric material may be porous and/or hydrophilic to allow penetration of moisture from the ambient environment into the moisture-sensitive dielectric material. InFIG.1, a moisture-insensitive dielectric material, such as SiO2or SiN, may be deposited or otherwise formed to fill the interstitial regions between the traces of the patterned metal layer108.

In an aspect, a further patterned metal layer114overlies the dielectric layer112and may be formed using the same material as patterned metal layer108. Together, the patterned metal layer108, dielectric layer112, and the patterned metal layer114form a capacitor116, shown in schematic format inFIG.1. The patterned metal layer108is shared by both the capacitor110and capacitor116. In this example, the capacitor116has a variable capacitance value, at least in the sense that the capacitance value varies in a detectable manner in the presence of moisture. InFIG.1, a dielectric material, such as SiO2or SiN, may be deposited or otherwise formed to fill the interstitial regions between the traces of the patterned metal layer114.

In an aspect, the patterned refractory metal layer102and patterned metal layers114and108have substantially the same patterns so that the traces of the layers are aligned and have the same height and width. By using substantially the same patterns, any detectable difference between the capacitances of capacitors110and116will be principally based on the moisture content of the moisture-sensitive dielectric layer112. In certain scenarios, capacitor110may serve as a reference capacitor with respect to the variable capacitance of the moisture-sensitive capacitor116.

FIGS.2A and2Bdepict various views of an example moisture sensor200, according to aspects of the disclosure.FIG.2Ais a top cutaway view of the moisture sensor200including an air gap216.FIG.2Bis a cross-sectional view of the moisture sensor200taken along line2B-2B ofFIG.2A.

InFIG.2B, the moisture sensor200includes separate capacitor banks202and204that are arranged in a side-by-side architecture. Here, capacitor bank204includes a fixed-value capacitor206and a moisture-sensitive capacitor208, while capacitor bank202includes a fixed-value capacitor210and a fixed-value capacitor212. The capacitor banks202and204are formed as an integrated structure with a dielectric material in region214that is configured to isolate the capacitor banks202and204from one another. In an aspect, the capacitor banks202and204may be further isolated from one another by forming the air gap216in the dielectric material of region214. The capacitor bank204may be formed in the same or similar manner as shown in the moisture sensor100ofFIG.1.

In an aspect, some of the structures of the capacitor bank202may be formed in the same processing operations used to form the corresponding structures of capacitance bank204. As shown inFIG.2B, the capacitor bank202includes a patterned refractory metal layer218disposed over a substrate220. The patterned refractory metal layer218may be disposed coplanar with the patterned refractory metal layer222. In an aspect, the patterned refractory metal layers218and222are formed from the same refractory metal.

The capacitor bank202includes a dielectric layer224formed from a moisture-insensitive dielectric material that is disposed over the patterned refractory metal layer218. The dielectric layer224is coplanar with the dielectric layer226of the capacitance bank204and may be formed from the same material as the dielectric layer226. A further patterned metal layer228is disposed over the dielectric layer224and is coplanar with the patterned metal layer230of the capacitor bank204. The patterned refractory metal layer218, the dielectric layer224, and the patterned metal layer228form fixed-value capacitor210.

The capacitor bank202also includes a dielectric layer232formed from a moisture-sensitive dielectric material that disposed over the patterned metal layer228and is coplanar with the dielectric layer234of capacitor bank204. The material used to form dielectric layer232may be the same dielectric material used to form dielectric layer224. A still further patterned metal layer236is disposed over the dielectric layer232and is coplanar with the patterned metal layer238of the capacitor bank204. In this example, the patterned metal layer236, the dielectric layer232, and the patterned metal layer228form the capacitor212, which shares the patterned metal layer228with the capacitor210.

In an aspect, the patterned refractory metal layers and patterned metal layers may all have substantially the same patterns so that the traces forming the respective capacitors are aligned and have the same height and width. By using substantially the same patterns, any detectable difference between the capacitances of the capacitors206,208,210, and212will be principally based on the moisture content of the moisture-sensitive dielectric layer234. In certain scenarios, the capacitors206,210, and212are fixed value capacitors that may serve as reference capacitors with respect to the variable capacitance of the moisture-sensitive capacitor208.

FIG.3depicts an example moisture sensor300, according to aspects of the disclosure. The construction of the moisture sensor300is similar to the construction of the moisture sensor200shown inFIGS.2A and2B. As shown, the moisture sensor300includes a pair of side-by-side capacitor banks302and304that are separated from one another by an isolating dielectric material322including an air gap324. The capacitor bank302includes capacitors306and308, while capacitor bank304includes capacitors310and312. In this example, the dielectric layer314of the capacitor306is formed of a moisture-sensitive dielectric material, thereby making the capacitor306a moisture-sensitive capacitor. Similarly, the dielectric layer316of capacitor310is formed from a moisture-sensitive dielectric material, thereby making the capacitor310a moisture-sensitive capacitor. In contrast, capacitors308and312may be fixed-value capacitors.

The capacitor308includes a patterned refractory metal layer318that may serve as both a plate of the capacitor308as well as a heating element to remove moisture from the dielectric layer314. Similarly, the capacitor312includes a patterned refractory metal layer320that may serve as both a plate of the capacitor312and a heating element that may be used to remove moisture from dielectric layer316. Moisture sensors having multiple moisture-sensitive capacitors may be used in scenarios in which a measurement of relative humidity is desired.

FIG.4depicts an example moisture sensor400, according to aspects of the disclosure. The construction of the moisture sensor400is likewise similar to the construction of the moisture sensor200shown inFIGS.2A and2B. The moisture sensor400includes a pair of side-by-side capacitor banks402and404that are separated by an isolating dielectric material422including an air gap424. The capacitor bank402includes the capacitors406and408while capacitor bank404includes the capacitors410and412. In this example, the dielectric layer414of the capacitor410is formed of a moisture-sensitive dielectric material thereby making the capacitor410a moisture-sensitive capacitor. Similarly, the dielectric layer416of capacitor412is formed from a moisture-sensitive dielectric material, thereby making the capacitor412a moisture-sensitive capacitor. In contrast, capacitors406and408may be fixed-value capacitors. A moisture sensor having multiple moisture-sensitive capacitors may be used in scenarios in which a measurement of relative humidity is desired.

The capacitor408includes a patterned refractory metal layer418that may serve as both a plate of the capacitor408as well as a heating element that may be used, for example, to control the temperature of the moisture sensor400. Similarly, the capacitor412includes a patterned refractory metal layer418that may serve as both a plate of the capacitor412and a heating element that may be used to reduce the moisture in dielectric layers414and416. As noted above, a moisture sensor having multiple moisture-sensitive capacitors may be used in scenarios in which a measurement of relative humidity is desired.

FIG.5depicts an example moisture sensor500, according to aspects of the disclosure. In this example, the moisture sensor500includes a moisture-sensitive capacitor502formed by patterned metal layers504and506and a moisture-sensitive dielectric layer508. The moisture sensor500further includes a fixed value capacitor510formed by the patterned metal layer506, a dielectric layer512formed from a moisture-insensitive dielectric material, and a patterned refractory metal layer514. The patterned refractory metal layer514may serve as both a plate of the capacitor510and a heating element that may be used to reduce the moisture in dielectric layer512.

In accordance with various aspects of the disclosure, the moisture sensor500may include additional layers that overlie the structures forming the capacitors502and510. InFIG.5, the additional layers of the moisture sensor500include a layer516of fluorosilicate glass (FSG) or silicon nitride disposed over portions of the dielectric layer512and the patterned metal layer504. A polyimide layer518may be disposed over the layer516and portions of the patterned metal layer504exposed by the layer516. A polymer coating520that allows moisture to pass to the dielectric layer508may be disposed about the exterior of the moisture sensor500.

FIG.6depicts an example moisture sensor600, according to aspects of the disclosure. In this example, the moisture sensor600includes side-by-side capacitor banks602,604that are isolated from one another by an air gap606. The capacitor bank602includes a moisture-sensitive capacitor608and a fixed-value capacitor610. The capacitor bank604includes a moisture-sensitive capacitor612and a fixed-value capacitor614. In an aspect, the fixed value capacitors610,614may share a common refractory metal layer616which may function as plates of each capacitor610,614as well as serving as a heating element to reduce the moisture in the moisture-sensitive dielectric layers618,620of the moisture-sensitive capacitors608,612. In certain scenarios, the refractory metal layer616may be patterned so as to form separate plates for the fixed value capacitors610,614as well as separate heating elements that, in certain aspects, may be operated independent of one another.

In accordance with various aspects of the disclosure, the moisture sensor600may include additional layers that overlie the structures forming the capacitors608and612. InFIG.6, the additional layers of the moisture sensor600may include a layer622of fluorosilicate glass (FSG) or silicon nitride and a polyimide layer624disposed over the layer622. A polymer coating626that allows moisture to pass to the dielectric layers618and620may be disposed about the exterior of the moisture sensor600.

FIG.7depicts an example moisture sensor700, according to aspects of the disclosure. In this example, the moisture sensor700includes a moisture-sensitive capacitor702and a fixed-value capacitor704. The moisture-sensitive capacitor702is formed from patterned metal layers706,708disposed at opposite sides of a moisture-sensitive dielectric layer710. The fixed value capacitor704is formed from the patterned metal layer708, dielectric layer712formed from a moisture-insensitive dielectric material, and a refractory metal layer714. In an aspect, the refractory metal layer714may be patterned with a pattern that matches the pattern of the patterned metal layer708.

In accordance with various aspects of the disclosure, the moisture sensor700may include additional layers that overlie the structures forming the capacitor702. InFIG.7the additional layers of the moisture sensor700may include a layer716of fluorosilicate glass (FSG) or silicon nitride and a polyimide layer718disposed over the layer716. A polymer coating720that allows moisture to pass to the dielectric layer710through a window region722may be disposed about the exterior of the moisture sensor700.

FIG.8depicts an example moisture sensor800, according to aspects of the disclosure. In this example, the moisture sensor800includes a moisture-sensitive capacitor802formed by patterned metal layers804and806and a moisture-sensitive dielectric layer808. The moisture sensor800further includes a fixed value capacitor810formed by the patterned metal layer806, a dielectric layer812formed from a moisture-insensitive dielectric material, and a patterned refractory metal layer814. The patterned refractory metal layer814may serve as both a plate of the capacitor810and a heating element that may be used to reduce the moisture in dielectric layer812.

In an aspect, the example moisture sensor800may include additional heating elements to reduce the moisture in dielectric layer812. In an aspect, the patterned metal layer804may be formed from a refractory metal and connected as the additional heating element to electrical power. In the example shown inFIG.8, the additional heating element includes a patterned refractory metal layer816disposed over the patterned metal layer804. The patterned metal layer804may be formed from the same refractory metal as refractory metal layer816or may be formed from a different metal. InFIG.8, a dielectric layer818is disposed over the patterned refractory metal layer816, and another patterned metal layer820is disposed over the dielectric layer818. Together, the patterned refractory metal layer816, dielectric layer,818, and patterned metal layer820may form a further capacitor822. An aspect, further capacitor822may be coupled in a frequency-sensitive circuit, such as one or more of the frequency-sensitive circuits described herein.

In accordance with various aspects of the disclosure, the moisture sensor800may include additional layers that overlie the structures forming the capacitor802,810, and810. InFIG.8, the additional layers of the moisture sensor800include a layer824of fluorosilicate glass (FSG) or silicon nitride disposed over portions of the dielectric layer812and the patterned metal layer820. A polyimide layer826may be disposed over the layer824and portions of the patterned metal layer820exposed by the layer824. A polymer coating828that allows moisture to pass to the dielectric layer808may be disposed about the exterior of the moisture sensor800. But

FIG.9shows an example of an electronic system900that may be coupled to a moisture sensor902, according to aspects of the disclosure. In an aspect, the electronic system900is a frequency-sensitive electronic circuit that is responsive to changes in capacitance resulting from exposure of the moisture-sensitive dielectric layer(s) included in the moisture sensor902to moisture. In this example, the passive components904(e.g., moisture sensor component(s), such as moisture-sensitive capacitors, and reference components, such as a fixed value reference capacitors) may be used with other electronic components to make a frequency filter and/or frequency generator906. The frequency filter/generator906has a frequency response that is dependent on the value of the moisture-sensitive component(s) (e.g., moisture-sensitive capacitor(s)). In an aspect, the frequency response corresponds to the amount of moisture absorbed by the moisture-sensitive dielectric material of the moisture-sensitive component(s), which may be correlated with the humidity (e.g. ambient humidity, relative humidity, etc.). The frequency response of the frequency filter/generator906may be detected by a sensing circuit908, which may provide an output signal indicative of the measured humidity.

The electronic system900may also include a heating element control system910that is connected to the refractive metal layer(s)912used to form at least some of the passive components904of the moisture sensor902. When activated, the heating element control system910provides electrical power to the refractive metal layer(s)912to heat any moisture-sensitive dielectric layer(s) that are proximate the refractive metal layer(s)912.

FIG.10illustrates a humidity detection cycle that may be performed by the electronic system900, according to aspects of the disclosure. In this example, the moisture in the moisture-sensitive dielectric materials of the moisture sensor902is driven to a baseline level. Graph1000shows an example of a baseline frequency response curve1002of the frequency filter/generator906. In an aspect, the moisture in the moisture-sensitive dielectric materials may be driven to the baseline level by heating the moisture-sensitive dielectric materials through the application of electrical power to the refractive metal layer(s)912by the heating element control system910.

During a sensing cycle, moisture (e.g., from the ambient environment) is allowed to penetrate the moisture-sensitive dielectric materials of the moisture sensor902. The increase in the moisture of the moisture-sensitive dielectric material(s) causes a corresponding change in the dielectric constant value(s) of the moisture-sensitive dielectric materials used to form the passive moisture-sensitive components of the moisture sensor902. Changes in the dielectric constant value result in a corresponding changes in the frequency response of the frequency filter/generator906. Graph1004shows an example of a change in the frequency response of the frequency filter/generator906, where response curve1006corresponds to the frequency response of the moisture sensor902during the sensing cycle. In this example, the frequency response curve1006has a peak that is shifted in frequency by a frequency differential Δfr from the peak of the baseline frequency response curve1002. In certain scenarios, the frequency response curve1006may also experience an amplitude shift ΔAmp from the peak amplitude of the baseline frequency response curve1002. Once the humidity has been measured by the electronic system900, the heating element control system910may provide power to the refractive metal layer(s) to heat the moisture-sensitive dielectric layer(s) of the moisture sensor902and drive the frequency of response of the frequency filter/generator906to the baseline response indicated by baseline frequency response curve1002.

FIG.11is a schematic of an example filter circuit1100that may be incorporated in a frequency filter/generator906, according to aspects of the disclosure. The filter circuit1100may be implemented with the capacitors C1, C2of a single capacitor bank of the moisture sensor902. In this example, a pair of resistors R1and R2are configured with the capacitors C1, C2to form the filter circuit1100. In an aspect, either one or both capacitors C1, C2may be moisture-sensitive capacitors. As such, the frequency response of the filter Vout/Vin is dependent on the moisture content of the moisture-sensitive dielectric layer(s) of the moisture-sensitive capacitors of the moisture sensor902.

FIG.12is a schematic of an example active filter circuit1200that may be used to implement the frequency filter/generator906, according to aspects of the disclosure. The active filter circuit1200includes an operational amplifier1202that is coupled to the capacitors C1, C2, C3, and C4of a multiple capacitor bank moisture sensor. In this example, capacitor C1is a moisture-sensitive capacitor and is depicted as a variable capacitor. In contrast, capacitors C2, C3, and C4are the fixed-value capacitors of the multiple capacitor banks. However, it will be recognized, based on the teachings of the disclosure, that capacitors C1, C2, C3, and C3of the active filter circuit1200may include any combination of moisture-sensitive capacitors and fixed value reference capacitors and still have a frequency response Vout/Vin that varies with the moisture content of the moisture-sensitive dielectric layers of the moisture-sensitive capacitors.

FIG.13is a graph1300of example frequency response curves of an active filter circuit (e.g., active filter circuit1200) under various humidity conditions, according to aspects of the disclosure. In this example, the frequency response curve1302represents the baseline frequency response. The frequency response curve1304represents an example frequency response of the active filter circuit when the relative humidity is 10%. The frequency response curve1306represents an example frequency response of the active filter when the relative humidity is 50%. The frequency response curve1308represents an example frequency response of the active filter when the relative humidity is 100%. It will be recognized, based on the teachings of the disclosure, that various active filter configurations will provide different frequency response curves under different humidity conditions.

According to certain aspects of the disclosure, the moisture sensor may be configured to implement a fixed-value inductor.FIG.14illustrates an example moisture sensor1400having a fixed value inductor, according to aspects of the disclosure. In this example, the fixed value inductor1402is implemented as a winding pattern of at least one of the patterned layers (e.g., patterned metal layers and/or patterned refractory metal layer) of the moisture sensor.FIG.15is a schematic diagram of a passive filter circuit1500formed using a fixed value inductor1402and moisture-sensitive capacitor C1of the moisture sensor1400, according to aspects of the disclosure.

FIG.16is a graph1600of example frequency response curves for a passive filter circuit including a fixed value inductor (e.g., passive filter circuit1500) under various humidity conditions, according to aspects of the disclosure. In this example, the frequency response curve1602represents the baseline frequency response. The frequency response curve1604represents an example frequency response of the passive filter circuit1500when the relative humidity is 10%. The frequency response curve1606represents an example frequency response of the passive filter circuit1500when the relative humidity is 50%. The frequency response curve1608represents an example frequency response of the passive filter circuit1500when the relative humidity is 100%. It will be recognized, based on the teachings of the disclosure, that various filter configurations incorporating the fixed inductor and moisture-sensitive capacitor will provide different frequency response curves under different humidity conditions.

The disclosed moisture sensors may be used in different packaging scenarios.FIG.17illustrates an example packaging scenario1700for an electronic circuit that includes a plurality of moisture sensors, according to aspects of the disclosure. In the packaging scenario1700, an electronic circuit1702is mounted on or formed in a substrate1704. The electronic circuit1702is bounded on all sides by a moisture barrier1710. A plurality of moisture sensors1708, having any of the disclosed moisture sensor configurations shown inFIGS.1through7, are mounted on or formed in the same substrate1704as electronic circuit1702in regions of the substrate1704exterior to the moisture barrier1710. In accordance with certain aspects of the disclosure, the electronic circuit1702may include components (e.g., frequency filter/generator components, sensing circuit components, heating element control system components, etc.) that are connected to facilitate the functioning of the moisture sensors1708in their role as humidity detectors.

FIG.18illustrates an example packaging scenario1800for an electronic circuit that includes a plurality of moisture sensors, according to aspects of the disclosure. In the packaging scenario1800, an electronic circuit1802is mounted on or formed in a substrate1804. A plurality of moisture sensors1806, having any of the disclosed moisture sensor configurations shown inFIGS.1through8, are mounted on or formed in the substrate1804. Each of the moisture sensors1806are separated from the electronic circuit1802by respective moisture barriers1808. In accordance with certain aspects of the disclosure, the electronic circuit1802may include components (e.g., frequency filter/generator components, sensing circuit components, heating element control system components, etc.) that are connected to facilitate the functioning of the moisture sensors1806in their role as humidity detectors.

FIG.19illustrates an example packaging scenario1900for an electronic circuit that includes a moisture sensor, according to aspects of the disclosure. In the packaging scenario1900, an electronic circuit1902is mounted on or formed in a substrate1904. A moisture sensor1906, having a moisture sensor configuration such as shown inFIG.1, is mounted on or formed in the substrate1904about the periphery of the electronic circuit1902. In an aspect, the moisture sensor1906may be isolated from the electronic circuit1902by a moisture barrier1908. In accordance with certain aspects of the disclosure, the electronic circuit1902may include components (e.g., frequency filter/generator components, sensing circuit components, heating element control system components, etc.) that are connected to facilitate the functioning of the moisture sensor1906in its role as a humidity detector.

FIG.20shows an example method2000for fabricating a moisture sensor, according to aspects of the disclosure. At operation2002, a first patterned refractory metal layer is formed that overlies a substrate. At operation2004, a first dielectric layer is formed over the first patterned refractory metal layer. At operation2006, a second patterned metal layer is formed over the first dielectric layer. At operation2008, a second moisture-sensitive dielectric layer is formed over the second patterned metal layer. At operation2010, a third patterned metal layer is formed over the second moisture-sensitive dielectric layer. Operation2012describes the components formed by the various layers formed in operations2002through2010, where the first patterned refractory metal layer, the first dielectric layer, and the second patterned metal layer form a first capacitor, and the third patterned metal layer, the second moisture-sensitive dielectric layer, and the second patterned metal layer form a second capacitor that is moisture-sensitive in which the second patterned metal layer is shared with the first capacitor, and the first patterned refractory metal layer is further configured for connection to electrical power as a heating element to assist in removing moisture from the second moisture-sensitive dielectric layer of the first capacitor in response to provision of the electrical power to the first patterned refractory metal layer.

FIG.21illustrates a profile view of a package2100that includes a surface mount substrate2102, an integrated device2103, and an integrated passive device2105(e.g., moisture sensor), according to aspects of the disclosure. The package2100may be coupled to a printed circuit board (PCB)2106through a plurality of solder interconnects2110. The PCB2106may include at least one board dielectric layer2160and a plurality of board interconnects2162.

The surface mount substrate2102includes at least one dielectric layer2120(e.g., substrate dielectric layer), a plurality of interconnects2122(e.g., substrate interconnects), a solder resist layer2140and a solder resist layer2142. The integrated device2103may be coupled to the surface mount substrate2102through a plurality of solder interconnects2130. The integrated device2103may be coupled to the surface mount substrate2102through a plurality of pillar interconnects2132and the plurality of solder interconnects2130. The integrated passive device2105may be coupled to the surface mount substrate2102through a plurality of solder interconnects2150. The integrated passive device2105may be coupled to the surface mount substrate2102through a plurality of pillar interconnects2152and the plurality of solder interconnects2150.

The package (e.g.,2100) may be implemented in a radio frequency (RF) package. The RF package may be a radio frequency front end (RFFE) package. A package (e.g.,2100) may be configured to provide Wireless Fidelity (WiFi) communication and/or cellular communication (e.g., 2G, 3G, 4G, 5G). The package (e.g.,2100) may be configured to support Global System for Mobile (GSM) Communications, Universal Mobile Telecommunications System (UMTS), and/or Long-Term Evolution (LTE). The package (e.g.,2100) may be configured to transmit and receive signals having different frequencies and/or communication protocols.

FIG.22illustrates an example method2200for providing or fabricating a package that includes an integrated device comprising a moisture sensor, according to aspects of the disclosure. In some implementations, the method2200ofFIG.22may be used to provide or fabricate the package2100ofFIG.21described in the disclosure. However, the method2200may be used to provide or fabricate any of the packages described in the disclosure.

It should be noted that the method ofFIG.22may combine one or more processes in order to simplify and/or clarify the method for providing or fabricating a package that includes an integrated device comprising a magnetic layer and/or an integrated passive device comprising a magnetic layer. In some implementations, the order of the processes may be changed or modified.

The method provides (at2205) a substrate (e.g.,2102). The substrate2102may be provided by a supplier or fabricated. The substrate2102includes at least one dielectric layer2120, and a plurality of interconnects2122. The substrate2102may include an embedded trace substrate (ETS). In some implementations, the at least one dielectric layer2120may include prepreg layers.

The method couples (at2210) at least one integrated device (e.g.,2103) to the first surface of the substrate (e.g.,2102). For example, the integrated device2103may be coupled to the substrate2102through the plurality of pillar interconnects2132and the plurality of solder interconnects2130. The plurality of pillar interconnects2132may be optional. The plurality of solder interconnects2130are coupled to the plurality of interconnects2122. A solder reflow process may be used to couple the integrated device2103to the plurality of interconnects through the plurality of solder interconnects2130.

The method also couples (at2210) at least one integrated passive device (e.g.,2105) to the first surface of the substrate (e.g.,2102). For example, the integrated passive device2105may be coupled to the substrate2102through the plurality of pillar interconnects2152and the plurality of solder interconnects2150. The plurality of pillar interconnects2152may be optional. The plurality of solder interconnects2150are coupled to the plurality of interconnects2122. A solder reflow process may be used to couple the integrated passive device2105to the plurality of interconnects through the plurality of solder interconnects2150.

The method couples (at2215) a plurality of solder interconnects (e.g.,2110) to the second surface of the substrate (e.g.,2102). A solder reflow process may be used to couple the plurality of solder interconnects2110to the substrate.

FIG.23illustrates various electronic devices that may be integrated with any of the aforementioned devices, integrated devices, integrated circuit (IC) packages, integrated circuit (IC) devices, semiconductor devices, integrated circuits, dies, interposer packages, package-on-package (POP), System in Package (SiP), or System on Chip (SoC). For example, a mobile phone device2302, a laptop computer device2304, a fixed location terminal device2306, a wearable device2308, or automotive vehicle2310may include a device2300as described herein. The device2300may be, for example, any of the devices and/or integrated circuit (IC) packages described herein. The devices2302,2304,2306and2308and the vehicle2310illustrated inFIG.23are merely exemplary. Other electronic devices may also feature the device2300including, but not limited to, a group of devices (e.g., electronic devices) that includes mobile devices, hand-held personal communication systems (PCS) units, portable data units such as personal digital assistants, global positioning system (GPS) enabled devices, navigation devices, set top boxes, music players, video players, entertainment units, fixed location data units such as meter reading equipment, communications devices, smartphones, tablet computers, computers, wearable devices (e.g., watches, glasses), Internet of things (IoT) devices, servers, routers, electronic devices implemented in automotive vehicles (e.g., autonomous vehicles), or any other device that stores or retrieves data or computer instructions, or any combination thereof.

Implementation examples are described in the following numbered aspects:Aspect 1. A device comprising: a first patterned metal layer; a first dielectric layer disposed over the first patterned metal layer; a second patterned metal layer disposed over the first dielectric layer, wherein the first patterned metal layer, the first dielectric layer, and the second patterned metal layer form a first capacitor; a second moisture-sensitive dielectric layer disposed over the second patterned metal layer; and a third patterned metal layer disposed over the second moisture-sensitive dielectric layer, wherein the third patterned metal layer, the second moisture-sensitive dielectric layer, and the second patterned metal layer form a second capacitor, the second patterned metal layer is shared with the first capacitor, and the first patterned metal layer is further configured for connection to electrical power as a heating element to assist in removing moisture from the second moisture-sensitive dielectric layer of the second capacitor.Aspect 2. The device of aspect 1, further comprising: a first frequency-sensitive circuit formed using at least the first capacitor and the second capacitor, wherein the first frequency-sensitive circuit has a first frequency response that changes based at least on a variable capacitance value of the second capacitor resulting from exposure of the second moisture-sensitive dielectric layer to moisture.Aspect 3. The device of aspect 2, wherein: the first dielectric layer is formed from a moisture-insensitive dielectric material; and the first capacitor is configured as a first reference capacitor in the first frequency-sensitive circuit.Aspect 4. The device of aspect 1, wherein: the first dielectric layer is formed as a moisture-sensitive dielectric layer to form the first capacitor as a moisture-sensitive capacitor.Aspect 5. The device of aspect 4, further comprising: a second frequency-sensitive circuit formed using the first capacitor and the second capacitor, wherein the second frequency-sensitive circuit has a second frequency response that changes based at least on variable capacitance values of the first capacitor and the second capacitor resulting from exposure of the first dielectric layer and the second moisture-sensitive dielectric layer to moisture.Aspect 6. The device of any of aspects 1 to 5, further comprising: a fourth patterned metal layer disposed coplanar with the first patterned metal layer, wherein the first patterned metal layer and the fourth patterned metal layer are formed from a same metal; a third dielectric layer disposed over the fourth patterned metal layer and coplanar with the first dielectric layer; a fifth patterned metal layer disposed over the third dielectric layer and coplanar with the second patterned metal layer, wherein the fourth patterned metal layer, the third dielectric layer, and the fifth patterned metal layer form a third capacitor; a fourth dielectric layer disposed over the fifth patterned metal layer and coplanar with the second moisture-sensitive dielectric layer; and a sixth patterned metal layer disposed over the fourth dielectric layer and coplanar with the third patterned metal layer, wherein the sixth patterned metal layer, the fourth dielectric layer, and the fifth patterned metal layer form a fourth capacitor in which the fifth patterned metal layer is shared with the third capacitor.Aspect 7. The device of aspect 6, wherein: the first dielectric layer, the third dielectric layer, and the fourth dielectric layer are formed from a moisture-insensitive dielectric material.Aspect 8. The device of any of aspects 6 to 7, further comprising: a third frequency-sensitive circuit formed using the first capacitor, the second capacitor, the third capacitor, and the fourth capacitor, wherein the third frequency-sensitive circuit has a third frequency response that changes based at least on a variable capacitance value of the second capacitor resulting from exposure of the second moisture-sensitive dielectric layer to moisture.Aspect 9. The device of aspect 6, wherein: the fourth dielectric layer is formed from a same moisture-sensitive dielectric material as the second moisture-sensitive dielectric layer to form the fourth capacitor as a moisture-sensitive capacitor.Aspect 10. The device of aspect 9, further comprising: a fourth frequency-sensitive circuit formed using the first capacitor, the second capacitor, the third capacitor, and the fourth capacitor, wherein the fourth frequency-sensitive circuit has a fourth frequency response that changes based at least on variable capacitance values of the second capacitor and the fourth capacitor resulting from exposure of the second moisture-sensitive dielectric layer and the fourth dielectric layer to moisture.Aspect 11. The device of aspect 10, wherein: the first dielectric layer and the third dielectric layer are formed from a same moisture-insensitive dielectric material; and the first capacitor and the third capacitor are configured as reference capacitors in the fourth frequency-sensitive circuit.Aspect 12. The device of any of aspects 6 to 11, wherein: the first capacitor and the second capacitor are separated from the third capacitor and the fourth capacitor by an isolating structure formed from a dielectric material, wherein the dielectric material includes an air gap therein to further isolate the first capacitor and the second capacitor from the third capacitor and the fourth capacitor.Aspect 13. The device of any of aspects 1 to 12, wherein: the third patterned metal layer is further configured for connection to the electrical power as a further heating element to assist in removing moisture from the second moisture-sensitive dielectric layer of the second capacitor.Aspect 14. The device of any of aspects 1 to 12, further comprising: a seventh patterned metal layer disposed over the third patterned metal layer, wherein the seventh patterned metal layer is further configured for connection to the electrical power as a further heating element.Aspect 15. The device of aspect 14, wherein: the third patterned metal layer and the seventh patterned metal layer are formed from a same metal.Aspect 16. The device of any of aspects 14 to 15, further comprising a fifth dielectric layer disposed over the seventh patterned metal layer; and an eighth patterned metal layer disposed over the fifth dielectric layer, wherein the seventh patterned metal layer, the fifth dielectric layer, and the eighth patterned metal layer form a fifth capacitor.Aspect 17. The device of any of aspects 1 to 16, further comprising: a heating element control system configured to provide the electrical power to the first patterned metal layer to control heating of the first patterned metal layer.Aspect 18. A method of forming a moisture sensor, comprising: forming a first patterned metal layer overlying a substrate; forming a first dielectric layer over the first patterned metal layer; forming a second patterned metal layer over the first dielectric layer; forming a second moisture-sensitive dielectric layer over the second patterned metal layer; and forming a third patterned metal layer over the second moisture-sensitive dielectric layer, wherein the first patterned metal layer, the first dielectric layer, and the second patterned metal layer form a first capacitor, the third patterned metal layer, the second moisture-sensitive dielectric layer, and the second patterned metal layer form a second capacitor, the second patterned metal layer is shared with the first capacitor, and the first patterned metal layer is further configured for connection to electrical power as a heating element to assist in removing moisture from the second moisture-sensitive dielectric layer of the second capacitor.Aspect 19. The method of aspect 18, further comprising: connecting a first frequency-sensitive circuit with the first capacitor and the second capacitor, wherein the first frequency-sensitive circuit has a first frequency response that changes based at least on a variable capacitance value of the second capacitor resulting from exposure of the second moisture-sensitive dielectric layer to moisture.Aspect 20. The method of any of aspects 18 to 19, wherein the first dielectric layer is formed from a moisture-insensitive dielectric material.Aspect 21. The method of aspect 18, wherein: the first dielectric layer is formed as a moisture-sensitive dielectric layer to form the first capacitor as a moisture-sensitive capacitor.Aspect 22. The method of any of aspects 18 to 21, further comprising: connecting a heating control circuit to provide the electrical power to the first patterned metal layer to control heating of the first patterned metal layer.Aspect 23. The method of any of aspects 18 to 22, further comprising: forming a fourth patterned metal layer disposed coplanar with the first patterned metal layer, wherein the first patterned metal layer and the fourth patterned metal layer are formed from a same metal; forming a third dielectric layer disposed over the fourth patterned metal layer and coplanar with the first dielectric layer; forming a fifth patterned metal layer disposed over the third dielectric layer and coplanar with the second patterned metal layer; forming a fourth dielectric layer disposed over the fifth patterned metal layer and coplanar with the second moisture-sensitive dielectric layer; and forming a sixth patterned metal layer disposed over the fourth dielectric layer and coplanar with the third patterned metal layer, wherein the fourth patterned metal layer, the third dielectric layer, and the fifth patterned metal layer form a third capacitor, and the sixth patterned metal layer, the fourth dielectric layer, and the fifth patterned metal layer form a fourth capacitor in which the fifth patterned metal layer is shared with the third capacitor.Aspect 24. The method of aspect 23, wherein: the first dielectric layer, the third dielectric layer, and the fourth dielectric layer are formed from a moisture-insensitive dielectric material.Aspect 25. The method of aspect 23, wherein: the fourth dielectric layer is formed from a same moisture-sensitive dielectric material as the second moisture-sensitive dielectric layer to form the fourth capacitor as a moisture-sensitive capacitor.Aspect 26. The method of aspect 25, wherein: the first dielectric layer and the third dielectric layer are formed from a same moisture-insensitive dielectric material.Aspect 27. The method of any of aspects 23 to 26, further comprising: forming an isolating structure that separates the first capacitor and the second capacitor from the third capacitor and the fourth capacitor, wherein the isolating structure includes a dielectric material, and wherein the dielectric material further includes an air gap formed therein to further isolate the first capacitor and the second capacitor from the third capacitor and the fourth capacitor.Aspect 28. A moisture sensor, comprising: a first capacitor having a first patterned metal layer, a first dielectric layer disposed over the first patterned metal layer, and a second patterned metal layer disposed over the first dielectric layer; a second capacitor having a second moisture-sensitive dielectric layer disposed over the second patterned metal layer, and a third patterned metal layer disposed over the second moisture-sensitive dielectric layer, wherein the second patterned metal layer is shared with the first capacitor; a first frequency-sensitive circuit formed using at least the first capacitor and the second capacitor, wherein the first frequency-sensitive circuit has a first frequency response that changes based at least on a variable capacitance value of the second capacitor resulting from exposure of the second moisture-sensitive dielectric layer to moisture; and a heating control circuit configured to provide electrical power to the first patterned metal layer to control heating of the first patterned metal layer to assist in removing moisture from the second moisture-sensitive dielectric layer of the second capacitor.Aspect 29. The moisture sensor of aspect 28, wherein: the first dielectric layer is formed from a same moisture-sensitive dielectric material as the second moisture-sensitive dielectric layer.Aspect 30. The moisture sensor of any of aspects 28 to 29, further comprising: a third capacitor having a fourth patterned metal layer coplanar with the first patterned metal layer, a third dielectric layer disposed over the fourth patterned metal layer and coplanar with the first dielectric layer, and a fifth patterned metal layer disposed over the third dielectric layer and coplanar with the second patterned metal layer; and a fourth capacitor having a fourth moisture-sensitive dielectric layer disposed over the fifth patterned metal layer and coplanar with the second moisture-sensitive dielectric layer, and a sixth patterned metal layer disposed over the fourth moisture-sensitive dielectric layer, wherein the fifth patterned metal layer is shared with the third capacitor.Aspect 31. The moisture sensor of aspect 30, wherein: the first frequency-sensitive circuit is further formed using the third capacitor and the fourth capacitor.Aspect 32. The moisture sensor of aspect 31, wherein: the fourth moisture-sensitive dielectric layer is formed from a same moisture-sensitive dielectric material as the second moisture-sensitive dielectric layer.Aspect 33. The moisture sensor of aspect 32, wherein: the first frequency response changes based at least on variable capacitance values of the second capacitor and the fourth capacitor resulting from exposure of the second moisture-sensitive dielectric layer and the fourth moisture-sensitive dielectric layer to moisture.Aspect 34. The moisture sensor of any of aspects 30 to 33, further comprising: an isolating dielectric material separating the first capacitor and the second capacitor from the third capacitor and the fourth capacitor, wherein the isolating dielectric material includes an air gap formed therein to further isolate the first capacitor and the second capacitor from the third capacitor and the fourth capacitor.

It is noted that the figures in the disclosure may represent actual representations and/or conceptual representations of various parts, components, objects, devices, packages, integrated devices, integrated circuits, and/or transistors. In some instances, the figures may not be to scale. In some instances, for purpose of clarity, not all components and/or parts may be shown. In some instances, the position, the location, the sizes, and/or the shapes of various parts and/or components in the figures may be exemplary. In some implementations, various components and/or parts in the figures may be optional.

The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation or aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects of the disclosure. Likewise, the term “aspects” does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation. The term “coupled” is used herein to refer to the direct or indirect coupling (e.g., mechanical coupling) between two objects. For example, if object A physically touches object B, and object B touches object C, then objects A and C may still be considered coupled to one another—even if they do not directly physically touch each other. The term “electrically coupled” may mean that two objects are directly or indirectly coupled together such that an electrical current (e.g., signal, power, ground) may travel between the two objects. Two objects that are electrically coupled may or may not have an electrical current traveling between the two objects. The use of the terms “first”, “second”, “third” and “fourth” (and/or anything above fourth) is arbitrary. Any of the components described may be the first component, the second component, the third component or the fourth component. For example, a component that is referred to a second component, may be the first component, the second component, the third component or the fourth component. The term “encapsulating” means that the object may partially encapsulate or completely encapsulate another object. The terms “top” and “bottom” are arbitrary. A component that is located on top may be located over a component that is located on a bottom. A top component may be considered a bottom component, and vice versa. As described in the disclosure, a first component that is located “over” a second component may mean that the first component is located above or below the second component, depending on how a bottom or top is arbitrarily defined. In another example, a first component may be located over (e.g., above) a first surface of the second component, and a third component may be located over (e.g., below) a second surface of the second component, where the second surface is opposite to the first surface. It is further noted that the term “over” as used in the present application in the context of one component located over another component, may be used to mean a component that is on another component and/or in another component (e.g., on a surface of a component or embedded in a component). Thus, for example, a first component that is over the second component may mean that (1) the first component is over the second component, but not directly touching the second component, (2) the first component is on (e.g., on a surface of) the second component, and/or (3) the first component is in (e.g., embedded in) the second component. A first component that is located “in” a second component may be partially located in the second component or completely located in the second component. The term “about ‘value X’”, or “approximately value X”, as used in the disclosure means within 10 percent of the ‘value X’. For example, a value of about 1 or approximately 1, would mean a value in a range of 0.9-1.1.

In some implementations, an interconnect is an element or component of a device or package that allows or facilitates an electrical connection between two points, elements and/or components. In some implementations, an interconnect may include a trace, a via, a pad, a pillar, a metallization layer, a redistribution layer, and/or an under bump metallization (UBM) layer/interconnect. In some implementations, an interconnect may include an electrically conductive material that may be configured to provide an electrical path for a signal (e.g., a data signal), ground and/or power. An interconnect may include more than one element or component. An interconnect may be defined by one or more interconnects. An interconnect may include one or more metal layers. An interconnect may be part of a circuit. Different implementations may use different processes and/or sequences for forming the interconnects. In some implementations, a chemical vapor deposition (CVD) process, a physical vapor deposition (PVD) process, a sputtering process, a spray coating, and/or a plating process may be used to form the interconnects.

Also, it is noted that various disclosures contained herein may be described as a process that is depicted as a flowchart, a flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed.

In the detailed description above, it can be seen that different features are grouped together in examples. This manner of disclosure should not be understood as an intention that the example aspects have more features than are explicitly mentioned in each aspect. Rather, the various aspects of the disclosure may include fewer than all features of an individual example aspect disclosed. Therefore, the following aspects should hereby be deemed to be incorporated in the description, wherein each aspect by itself can stand as a separate example. Although each dependent aspect can refer in the aspects to a specific combination with one of the other aspects, the aspect(s) of that dependent aspect are not limited to the specific combination. It will be appreciated that other example aspects can also include a combination of the dependent aspect aspect(s) with the subject matter of any other dependent aspect or independent aspect or a combination of any feature with other dependent and independent aspects. The various aspects disclosed herein expressly include these combinations, unless it is explicitly expressed or can be readily inferred that a specific combination is not intended (e.g., contradictory aspects, such as defining an element as both an electrical insulator and an electrical conductor). Furthermore, it is also intended that aspects of a aspect can be included in any other independent aspect, even if the aspect is not directly dependent on the independent aspect.

While the foregoing disclosure shows illustrative aspects of the disclosure, it should be noted that various changes and modifications could be made herein without departing from the scope of the disclosure as defined by the appended claims. The functions, steps and/or actions of the method claims in accordance with the aspects of the disclosure described herein need not be performed in any particular order. Furthermore, although elements of the disclosure may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.