Implementing sensor top side wire bonding

Abstract

The content provided herein includes examples of devices, sensor systems, and examples of methods for manufacturing aspects of the devices, sensor systems. The method can include forming bumps on surfaces of one or more electrical contacts, where the one or more electrical contacts are capable of contacting an upper surface of a die, where the die is oriented on a substrate, and where the electrical contacts include bond pads. The method can also include coupling one or more additional electrical contacts to the one or more electrical contacts, where the coupling includes wire bonding each of the additional electrical contacts to one of the one or more electrical contacts capable of contacting the upper surface of the die via a portion of the bumps on the surfaces of the one or more electrical contacts, thereby forming wire bonded connections.

Description

Background Technology

[0001] Various protocols in biological or chemical research involve conducting controlled reactions. The specified reactions can then be observed or detected, and subsequent analysis can help identify or reveal the properties of the chemicals involved in the reaction. In some multiplex assays, an unknown analyte with an identifiable label (e.g., a fluorescent label) is exposed to thousands of known probes under controlled conditions. Each known probe can be placed in a corresponding well of a microplate. Observing any chemical reactions occurring between the known probe and the unknown analyte within the well can help identify or reveal the properties of the analyte. Other examples of such protocols include known DNA sequencing processes such as sequencing-on-synthesis (SBS) or circular array sequencing.

[0002] In some fluorescence detection schemes, optical systems are used to direct excitation light onto fluorophores (e.g., fluorescently labeled analytes) and also to detect fluorescence emission signals emitted from analytes with connected fluorophores. In other proposed detection systems, the controlled reaction in the flow cell is detected by a solid-state optical sensor array (e.g., a complementary metal-oxide-semiconductor (CMOS) detector). These systems do not involve large optical components for detecting fluorescence emission. The shape of the fluid flow channels in the flow cell determines its utility for various applications, such as enabling SBS or cyclic array sequencing in a sensor system using multiple fluid flows, and thus, fluid flow channels of specific shapes are used for SBS or cyclic array sequencing.

[0003] To implement SBS in the aforementioned optical systems, electrical contacts are provided to the sensor (e.g., a CMOS used as a detector) in some of the described optical systems. Although it would seem more cost-effective and easier to configure to place them near the active surface of the sensor in the flow cell, certain components in the existing manufacturing processes for optical systems can damage the electrical contacts at this location, so many optical systems employ alternative locations for these contacts. Summary of the Invention

[0004] Therefore, it may be beneficial for flow cell manufacturing mechanisms to enable electrical contacts to be located on one side of the optical system, which also includes the active surface of the sensor in the system.

[0005] Therefore, the disadvantages of the prior art can be overcome, and the benefits described later in this disclosure can be achieved by providing a method for implementing a sensor on a top-side bonded die. Various examples of the method are described below, and the method (including and excluding the additional examples listed below) overcomes these disadvantages in any combination (provided that these combinations are not inconsistent). The method includes: forming bumps on the surfaces of one or more electrical contacts, wherein the one or more electrical contacts are capable of contacting an upper surface of a die, wherein the die is oriented on a substrate, and wherein the electrical contacts include bonding pads; and coupling additional electrical contacts to the one or more electrical contacts, wherein the coupling includes wire-bonding each of the additional electrical contacts to one of the one or more electrical contacts capable of contacting the upper surface of the die via a portion of the bumps on the surfaces of the one or more electrical contacts, thereby forming a wire-bonded connection.

[0006] In some examples, the die is oriented on the substrate such that a first space is defined in a cavity at a first edge adjacent to the upper surface of the die, and a second space is defined in a cavity at a second edge adjacent to the upper surface of the die, wherein the bottom fill layer includes a cavity between the lower surface of the die and the substrate.

[0007] In some examples, one or more electrical contacts comprise aluminum.

[0008] In some examples, the die includes complementary metal-oxide-semiconductor (CMOS).

[0009] In some examples, the active surface of the die includes a portion of the upper surface of the die, including nanopores, one or more contacts adjacent to the active surface, and forming bumps includes: removing a top oxide layer from the upper surface of the die; forming a seed layer on the upper surface of the die; applying a photoresist to the active surface of the die and patterning the photoresist, wherein the seed layer is exposed on a portion of the upper surface without the patterned photoresist; and electroplating a metal layer on the exposed seed layer, wherein electroplating includes applying a metal layer on one or more electrical contacts.

[0010] In some examples, the method also includes forming an initial photoresist on the active surface of the wafer and patterning the initial photoresist before forming the seed layer.

[0011] In some examples, the method also includes removing the photoresist.

[0012] In some examples, the active surface comprises an array of nanopores, and the method further includes removing the seed layer from the active surface by utilizing an etchant that retains the nanopore array.

[0013] In some examples, the method also includes removing the initial photoresist from the active surface of the die.

[0014] In some examples, removing photoresist involves using ultraviolet (UV) light to break down the cross-linked portions of the photoresist and removing the photoresist by applying a developer to the bare film.

[0015] In some examples, forming a seed layer involves sputtering material onto the upper surface of the die.

[0016] In some examples, the seed layer is made of metal.

[0017] In some examples, the material including the seed layer is selected from the group consisting of: titanium tungsten (TiW), copper (Cu), titanium copper (TiCu), and titanium (Ti).

[0018] In some examples, the material used for the bumps is selected from the group consisting of gold (Au), platinum (Pt), copper (Cu), and nickel (Ni).

[0019] In some examples, the method also includes coating the bare die with a polymer material and polishing a portion of the coating.

[0020] In some examples, one or more additional electrical contacts include substrate bonding pads, and one or more electrical contacts include die bonding pads.

[0021] In some examples, the bare wafer includes coated and polished nanopores.

[0022] The disadvantages of the prior art can be overcome, and the benefits described later in this disclosure are achieved by providing means for implementing a sensor on a top-side bonded die. Various examples of such means are described below, and the means (including and excluding the additional examples listed below) overcome these disadvantages in any combination (provided that such combinations are not inconsistent). The means includes: a substrate comprising a die, wherein the die is oriented on the substrate, including one or more electrical contacts with bonding pads oriented on an upper surface of the die, and wherein a portion of the upper surface of each of the one or more electrical contacts is layered with a coating including metal bumps; one or more additional electrical contacts, each of the one or more additional electrical contacts being electrically coupled to at least one of the one or more electrical contacts via a portion of a metal bump on at least one contact through wire bonding; and a fluid flow channel on an active surface of the die, wherein the active surface of the die includes a portion of the upper surface of the die including nanopores, wherein the one or more electrical contacts are adjacent to the active surface.

[0023] In some examples, the metal coating is selected from the group consisting of gold (Au), platinum (Pt), copper (Cu), and nickel (Ni).

[0024] In some examples, the die includes complementary metal-oxide-semiconductor (CMOS).

[0025] The disadvantages of the prior art can be overcome, and the benefits described later in this disclosure are achieved by providing a method for implementing a sensor on a top-side bonded die. Various examples of the method are described below, and the method (including and excluding the additional examples listed below) overcomes these disadvantages in any combination (provided that such combinations are not inconsistent). The method includes: forming bumps on a surface including one or more electrical contacts comprising bonding pads, wherein the one or more electrical contacts are capable of contacting an upper surface of a sensor utilized in a flow cell, wherein a portion of the top surface of the sensor includes an active surface, wherein the one or more bonding pads are positioned adjacent to the active surface, forming a bump comprising: removing a top oxide layer from the upper surface of the sensor; forming a seed layer on the upper surface of the sensor; applying a photoresist to the active surface of the sensor and patterning the photoresist, wherein the seed layer is exposed on a portion of the upper surface without the patterned photoresist; and electroplating a metal layer on the exposed seed layer, wherein the electroplating includes applying the metal layer on the one or more bonding pads.

[0026] In some examples, the method further includes forming an initial photoresist on the active surface of the sensor and patterning the initial photoresist before forming the seed layer.

[0027] In some examples, the method also includes removing the photoresist from a portion of the upper surface.

[0028] In some examples, the active surface comprises an array of nanopores, and the method further includes removing the seed layer from the active surface by utilizing an etchant that retains the nanopore array.

[0029] In some examples, the method also includes removing the initial photoresist from the active surface of the sensor.

[0030] In some examples, removing photoresist involves using ultraviolet (UV) light to break down the cross-linked portions of the photoresist and removing the photoresist by applying a color developer to the sensor.

[0031] In some examples, forming a seed layer involves sputtering material onto the upper surface of the sensor.

[0032] In some examples, the material including the seed layer is selected from the group consisting of: titanium tungsten (TiW), copper (Cu), titanium copper (TiCu), and titanium (Ti).

[0033] In some examples, the material used for the bumps is selected from the group consisting of gold (Au), platinum (Pt), copper (Cu), and nickel (Ni).

[0034] In some examples, the method includes coating the bare sheet with a polymer material; and polishing a portion of the coating.

[0035] In some examples, the method further includes using bumps on the bonding pads to couple additional electrical contacts to the bonding pads, wherein the coupling includes bonding each additional electrical contact lead in the additional electrical contacts to one of the bonding pads on the surface of the sensor via the bumps, thereby forming a wire-bonded connection.

[0036] In some examples, the sensor includes a complementary metal-oxide-semiconductor.

[0037] In some examples, the active surface includes coated and polished nanopores.

[0038] The drawbacks of the prior art can be overcome, and the benefits described later in this disclosure are achieved by providing a method for implementing a sensor on a top-side bonded die. Various examples of the method are described below, and the method (including and excluding the additional examples listed below) overcomes these drawbacks in any combination (provided that such combinations are not inconsistent). The method includes: forming bumps on the surface of one or more bonding pads, wherein the one or more bonding pads are capable of contacting an upper surface of a sensor used in a flow cell, wherein a portion of the top surface of the sensor includes an active surface, wherein the one or more bonding pads are positioned adjacent to the active surface, forming a bump including: removing a top oxide layer from the upper surface of the sensor; forming a seed layer on the upper surface of the sensor, wherein a first portion of the seed layer is formed on the one or more bonding pads and a second portion of the seed layer is formed on the active surface; applying a first photoresist on the one or more bonding pads and patterning the first photoresist; removing the second portion of the seed layer; applying a second photoresist on the active surface of the sensor and patterning the second photoresist; electroplating a metal layer on the first portion of the seed layer, wherein electroplating includes applying a metal layer on the one or more bonding pads; stripping the second photoresist; and stripping a segment of the first portion of the seed layer, wherein the segment is not covered by the metal layer.

[0039] In some examples, the method further includes using bumps on the bonding pads to couple exposed electrical contacts to the bonding pads, wherein coupling includes bonding each exposed electrical contact lead to one of the bonding pads on the surface of the sensor, thereby forming a wire-bonded connection.

[0040] Additional features are achieved through the techniques described herein. Other examples and aspects are described in detail herein and are considered part of the aspects protected by the claims. These and other objects, features, and advantages of this disclosure will become apparent from the following detailed description of various aspects of this disclosure in conjunction with the accompanying drawings.

[0041] It should be understood that all combinations of the foregoing aspects and the additional concepts discussed in more detail below (assuming that such concepts do not contradict each other) are contemplated as part of the subject matter of the invention and to realize the advantages disclosed herein. Attached Figure Description

[0042] One or more aspects are specifically pointed out and, by way of example, are clearly claimed in the claims at the end of this specification. The foregoing contents, objectives, features, and advantages of one or more aspects will become apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0043] Figures 1 to 2 An example depicting a portion of a flow cell including a top-side lead-connected electrical contact;

[0044] Figures 3A to 3F Examples of various aspects of a method for implementing a protective layer on electrical contacts on a sensor to achieve top-side engagement of the electrical contacts are described;

[0045] Figure 4 An example illustrating the effects of different workflow conditions on the fabrication of a sensor surface used in a flow cell on an electrical contact on the sensor surface is illustrated.

[0046] Figure 5 This is an example of a sensor with a protective layer;

[0047] Figure 6 This is an example of damage to the sensor when certain parts of the process disclosed herein are not performed;

[0048] Figures 7A to 7E Examples of various aspects of a method for implementing a protective layer on electrical contacts on a sensor to achieve top-side engagement of the electrical contacts are described;

[0049] Figures 8A to 8E Examples of various aspects of a method for implementing a protective layer on electrical contacts on a sensor to achieve top-side engagement of the electrical contacts are described;

[0050] Figure 9 Examples of various aspects of a method for implementing a protective layer on an electrical contact on a sensor to achieve top-side engagement of the electrical contact are illustrated;

[0051] Figure 10This illustrates a workflow for forming one or more example top-side electrical contacts on a bare die; and

[0052] Figure 11 It provides Figure 10 A workflow with more detailed refinement of certain aspects. Detailed Implementation

[0053] The accompanying drawings further illustrate specific embodiments of the invention and, together with the detailed description of the embodiments, serve to explain the principles of the specific embodiments of the invention. Similar reference numerals in the drawings refer to the same or functionally similar elements throughout the individual views, and the drawings are incorporated in and form a part of this specification. As will be understood by those skilled in the art, the drawings are provided to facilitate understanding and to illustrate aspects of certain examples of specific embodiments of the invention. Specific embodiments are not limited to the examples depicted in the drawings.

[0054] The terms “connection,” “linked,” “contact,” “coupled,” etc., are broadly defined herein to encompass a variety of distributed arrangement and assembly techniques. These arrangements and techniques include, but are not limited to: (1) a direct engagement of one component and another component without an intervening component (i.e., the components are in direct physical contact); and (2) an engagement of one component and another component with one or more components between them, provided that the one component is “connected to,” “contacted to,” or “coupled to” the other component is in some degree of operational communication with the other component (e.g., electrical, fluid, physical, optical, etc.) (despite the presence of one or more additional components). It should be understood that some components in direct physical contact with each other may be in electrical and / or fluid contact with each other or may not be in direct physical contact with each other. Furthermore, two components in an electrical connection, electrical coupling, optical connection, optical coupling, fluid connection, or fluid coupling may be in direct physical contact or may not be in direct physical contact, and one or more other components may be disposed between the two components.

[0055] As used in this article, the terms “include” and “contain” have the same meaning.

[0056] The terms “substantially,” “approximately,” “about,” “relatively,” or other such similar terms that may be used throughout this disclosure (including the claims) are used to describe and illustrate small fluctuations from a reference or parameter, such as due to variations in the process. Such small fluctuations also include zero fluctuations from a reference or parameter. For example, they may refer to less than or equal to ±10%, such as less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. If used herein, the terms “substantially,” “approximately,” “about,” “relatively,” or other such similar terms may also refer to no fluctuation, i.e., ±0%.

[0057] As used herein, a "flow cell" may include a device with a cap extending over a reaction structure to form flow channels therebetween communicating with multiple reaction sites of the reaction structure, and may include a detection device for detecting a specified reaction occurring at or near the reaction site. The flow cell may include a solid-state optical detection or "imaging" device, such as a charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) (optical) detection device. As a specific example, the flow cell may be fluidly and electrically coupled to a cartridge (with an integrated pump), which may be fluidly and / or electrically coupled to a bioassay system. The cartridge and / or bioassay system may deliver reaction solutions to the reaction sites of the flow cell according to a predetermined protocol (e.g., sequencing-by-synthesis) and perform multiple imaging events. For example, the cartridge and / or bioassay system may guide one or more reaction solutions through the flow channels of the flow cell, thereby flowing along the reaction site. At least one of the reaction solutions may contain four types of nucleotides with the same or different fluorescent labels. In some examples, nucleotides bind to the reaction sites of the flow cell, such as corresponding oligonucleotides bound to the reaction sites. The boxes and / or bioassay systems in these examples then illuminate the reaction sites using an excitation light source (e.g., a solid-state light source, such as a light-emitting diode (LED)). In some examples, the excitation light has one or more predetermined wavelengths, including a wavelength range. The fluorescent label excited by the incident excitation light can provide an emission signal (e.g., one or more wavelengths of light that are different from and may be different from each other) that can be detected by a light sensor in a flow cell.

[0058] The flow cells described herein perform various biological or chemical processes. More specifically, the flow cells described herein can be used in various processes and systems where it is desired to detect events, properties, quality, or characteristics indicating a specified reaction. For example, the flow cells described herein may include photodetectors, sensors (including but not limited to biosensors and components thereof), and bioassay systems that operate in conjunction with or are integrated with the aforementioned devices.

[0059] This flow cell facilitates multiple designated reactions that can be detected individually or together. The flow cell performs multiple cycles in which the multiple designated reactions occur in parallel. For example, the flow cell can be used to sequence a dense array of DNA features through iterative cycles of enzyme manipulation and light or image detection / acquisition. Thus, the flow cell may be fluidly communicated with one or more microfluidic channels that deliver reagents or other reaction components from the reaction solution to the reaction sites within the flow cell. The reaction sites may be provided or spaced in a predetermined manner, such as in a uniform or repetitive pattern. Alternatively, the reaction sites may be randomly distributed. Each of the reaction sites may be associated with one or more light guides and one or more photosensors that detect light from the associated reaction site. In one example, the light guide includes one or more filters for filtering certain wavelengths of light. The light guide may be, for example, an absorptive filter (e.g., an organic absorptive filter) such that the filtering material absorbs a specific wavelength (or wavelength range) and allows at least one predetermined wavelength (or wavelength range) to pass through it. In some flow cells, the reaction sites may be located in reaction recesses or reaction chambers, which may at least partially separate the designated reactions therein.

[0060] As used herein, a “designated reaction” includes a change in at least one of the chemical, electrical, physical, or optical properties (or mass) of a chemical or biological substance of interest (e.g., an analyte of interest). In a specific flow cell, a designated reaction is a positive binding event, such as the binding of a fluorescently labeled biomolecule to an analyte of interest. More generally, a designated reaction can be a chemical transformation, chemical change, or chemical interaction. A designated reaction can also be a change in electrical properties. In a specific flow cell, a designated reaction includes the binding of a fluorescently labeled molecule to an analyte. The analyte can be an oligonucleotide, and the fluorescently labeled molecule can be a nucleotide. A designated reaction can be detected when excitation light is directed to an oligonucleotide with a labeled nucleotide, and the fluorophore emits a detectable fluorescent signal. In another example of a flow cell, the detected fluorescence is the result of chemiluminescence or bioluminescence. A designated reaction can also increase fluorescence (or, for example, by bringing a donor fluorophore closer to an acceptor fluorophore). Resonance energy transfer (FRET) reduces FRET by separating the donor fluorophore and the acceptor fluorophore, increases fluorescence by separating the quencher group and the fluorophore, or reduces fluorescence by co-locating the quencher group and the fluorophore.

[0061] As used herein, “electrical coupling” and “optical coupling” refer to the transfer of electrical energy and optical waves between any combination of power sources, electrodes, conductive parts of a substrate, droplets, conductive traces, wires, waveguides, nanostructures, other circuit segments, etc. The terms “electrical coupling” and “optical coupling” can be used in conjunction with direct or indirect connections and can pass through various intermediates, such as fluid intermediates, air gaps, etc.

[0062] As used herein, “reaction solution,” “reaction component,” or “reactant” includes any substance that can be used to obtain at least one specified reaction. Possible reaction components include, for example, reagents, enzymes, samples, other biomolecules, and buffer solutions. The reaction component may be delivered to and / or immobilized at the reaction site in the flow cell disclosed herein. The reaction component may interact directly or indirectly with another substance, such as an analyte of interest immobilized at the reaction site in the flow cell.

[0063] As used herein, the term "reaction site" is a localized region on which at least one specified reaction may occur. A reaction site may include a reaction structure or a supporting surface of a substrate on which a substance can be immobilized. For example, a reaction site may include a surface (located in a channel of a flow cell) having a reaction structure on which a reaction component (such as a population of nucleic acids on which it is located) is formed. In some flow cells, the nucleic acids in the population have the same sequence, for example, clones of single-stranded or double-stranded templates. However, in some flow cells, the reaction site may contain only a single nucleic acid molecule, for example, in single-stranded or double-stranded form.

[0064] The term "active surface" is used herein to characterize a horizontal surface of a sensor or a detector within a package that operates as a sensor. For example, in an example where a CMOS sensor is used as a detector in a flow cell, the active surface is part of the CMOS sensor surface, including nanopores. Throughout this disclosure, the terms die and wafer are also used with reference to certain examples herein, as a die may include a sensor and a die is fabricated from a wafer. The terms wafer and substrate are also used interchangeably herein.

[0065] The term "fan-out" is used in this document to characterize the region that extends beyond the horizontal distance of the detector packaged with it. For example, in the case of a CMOS sensor used as a detector in a flow cell, fan-out refers to the additional horizontal distance on each side of the horizontal boundary of the CMOS sensor.

[0066] As used herein, the terms "pillar bump" and "bump" are used to describe the electrical contacts shown and described herein. Various examples of electrical contacts may also be used in the various examples of the apparatus shown herein, and wherever the terms "pillar bump" or "bump" are used. Electrical contacts (which may be pillar bumps or bumps) may comprise conductive materials, such as metallic materials (e.g., Cu (copper), Au (gold), W (tungsten), Al (aluminum), or combinations thereof), but it should be understood that other conductive materials may be utilized.

[0067] The following description refers to the accompanying drawings, which are not drawn to scale for ease of understanding. The same reference numerals are used in all the different drawings to denote the same or similar parts.

[0068] Various flow cell elements that contribute to flow cell functionality include the ability to electrically connect to the active surfaces of a sensor or detector (e.g., CMOS). Electrical connections (e.g., bonding pads, contact pads) formed to the wafer surface within the flow cell itself are desirable for enabling the flow cell to facilitate processes such as SBS. For example, these connections enable heat transfer from the silicon wafer. While direct wire bonding or other forms of electrical coupling to electrical contacts on the wafer surface are desirable from an efficiency and cost perspective, such direct connections are complicated by the ability of electrical contacts on the top surface of the wafer to maintain electrical integrity during wafer fabrication, a capability that enables the wafer to facilitate SBS and other processes. Forming usable electrical contacts on the top surface of a wafer presents at least two challenges, and the various aspects described herein address at least these challenges. In general, existing methods and techniques for forming contacts may pose challenges to: 1) electrical connections on the wafer surface; and 2) the active surfaces of the wafer, including but not limited to nanopores. Referring to the first non-limiting example, certain processes used to fabricate a wafer for performing SBS (such as coating and polishing the wafer (applying a chemical coating to the active surface and then polishing)) can significantly alter the shape of the top-side contact pads and make bonding with these pads from the top side impossible. Referring to the second non-limiting example, certain measures that can precisely achieve greater accessibility to the contacts may be incompatible with the desired functionality of the sensor. For example, adding layers to electrical contacts (e.g., contact pads, bonding pads, bump pads on the top side of the sensor) can be corrosive to nanopores on the active surface of the wafer, and without these nanopores to fully operate, SBS may be difficult to use with a flow cell. The examples described herein address these challenges, as will be discussed in further detail herein.

[0069] One approach to addressing the aforementioned challenges is to connect the electrical contacts not directly to the top side of the sensor or detector in the flow cell, but to these contacts from the bottom side of the substrate, in a manner that includes one or more through-silicon vias (TSVs) extending through a portion of the silicon wafer and a passivation stack. For example, the passivation stack is disposed below the lower surface of a portion of the silicon wafer, a portion of each of the one or more TSVs is exposed through an opening in one or more openings in the passivation stack, and each exposed portion is coupled to an electrical contact. By forming the electrical connection from the back side of the wafer instead of the top surface, processing on the wafer surface does not necessarily include the electrical contacts. However, the fabrication process for a flow cell that includes a passivation layer and TSVs to allow connection to the bottom side of the electrical contacts is more complex, and each part of the process may potentially introduce problems into the manufacturing process and the finished product. At least for this reason, it is desirable to fabricate or manufacture the flow cell in a manner that facilitates SBS and other processes by the sensor or detector in the flow cell, but allows for connection at the top side of the sensor or detector.

[0070] As disclosed herein, various processes can be used to achieve top-side wire bonding to sensors in a flow cell. The processes described herein are compatible with existing manufacturing methods because they preserve at least some of these existing aspects, but in at least some examples, an additional coating (e.g., a metallic coating) is added to the top-side contact pads, which are electrical contacts on sensors or detectors in various flow cells. This additional coating can withstand some processing of the top side of the sensor region of the flow cell and also enables wire bonding to the top side of the sensor. As will be described in more detail herein, in some examples of this process, a metallic layer (e.g., gold) can be added to utilize the photolithographic and masked area outside the contact pads on top of the sensor (e.g., a CMOS sensor). In some examples, the contact pads are aluminum wire bonding pads. As will be explained further in detail herein, some examples of the processes described herein involve two masking processes. Since electroplating occurs only or substantially only in the presence of a seed layer (e.g., titanium-tungsten (TiW)), this seed layer is patterned to minimize the edge effects of this bumping process around the (e.g., aluminum (Al)) bonding pads. Therefore, a second mask is used to pattern the photoresist.

[0071] Various examples and illustrations herein depict examples of methods for forming bumps (e.g., metallic bumps, including but not limited to gold (Au), platinum (Pt), copper (Cu), and / or nickel (Ni)) on the surface of one or more bonding pads. Forming these bumps enables bonding pads (e.g., aluminum) to contact the upper surface of a die, wherein the die is oriented on a substrate. While bonding pads are electrical contacts on the die surface, the areas of the die that can be electrically connected include both bonding pads and bumps, due to the ability to make electrical contacts (e.g., for wire bonding). One way to couple electrical contacts elsewhere in and / or outside the flow cell to bonding pads is to couple these electrical contacts to the bonding pads via bumps. Coupling may include wire bonding each electrical contact lead not on the die surface to one of the bonding pads (i.e., electrical contacts on the die surface) on the upper surface of the die via bumps, thereby forming a wire-bonded connection.

[0072] As described above, the various aspects of the examples described herein enable the fabrication and fabrication of a flow cell, wherein electrical contacts (e.g., bonding pads) are formed on the upper surface of the wafer, thereby enabling wire bonding and / or other electrical connections to these contacts via electrical contacts elsewhere in and / or outside the flow cell. For this purpose, Figures 1 to 2 These are illustrations of various portions of flow cells 100 and 200, illustrating the connection between electrical contacts formed on the active surface of the sensor or detector and these electrical contacts at the wafer top side. Figure 1 and Figure 2 In each of these examples of flow cells 100 and 200, electrical contacts 110 and 210 are disposed on the active surfaces 140 and 240 of the sensor or detector, and these electrical contacts (e.g., bonding pads) are wire-contacted to additional electrical contacts 117 and 217. The additional electrical contacts 117 and 217 are electrical contacts located elsewhere in the flow cell. The difference between these examples is that one includes a fan-out region while the other does not. These figures are included to illustrate the implementation of the top-side electrical coupling as described above through the examples disclosed herein. In each of these examples of flow cells 100 and 200, the sensor or detector utilized in the flow cell is a CMOS. Detection devices and image sensors that can be used as sensors (e.g., biosensors, including image sensors or detectors) in a flow cell include CMOS and fan-out regions, as well as those that do not include such regions. In detectors having such fan-out regions, the surface of the CMOS and the fan-out region (on either side) form an active surface. In flow cells that do not include such fan-out regions, the active surface is the upper surface of the sensor or detector.

[0073] Figures 1 to 2 Examples are given for having (e.g., Figure 1 ) and none (e.g., Figure 2 This fan-out region includes various aspects of the circulation pools 100 and 200. Figure 1 The circulation pool 100 includes a fan-out region 140. In Figure 1 and Figure 2 Of the two, CMOS (for example, Figure 1 Silicon wafer 130 Figure 2 Above the active surface of the silicon wafer 230 are (microscopic) fluid flow channels 111, 211, defined by capping or adjacent surfaces of flow pools 100, 200 on one side, including portions of the active surfaces 120, 220 of the silicon wafer and fan-out regions 142 on either side of the surface of the silicon wafer or the top surface of the wafer itself. To perform processes such as the aforementioned SBS, electrical contacts 110, 210 are disposed on the active surfaces 140, 240 of the sensor or detector. In both examples, these electrical contacts 110, 210, referred to as bonding pads, are formed on the top surface of the silicon wafer die, and wire bonds 123, 223 connect the contacts 110, 210 to additional electrical contacts 117, 217. Figure 1 and Figure 2 Both active surfaces 140 and 240 include at least one nanopore 150 and 250. For simplicity... Figures 1 to 2The illustrations in this paper focus on the top-side electrical connection for illustrative purposes, and therefore some aspects of the depicted flow cell examples are not labeled. As will be discussed herein, this top-side connection is implemented based on the various aspects described herein because the electrical integrity of the contacts on the active surface is preserved.

[0074] Figures 3A to 3F Various processes are described in examples of workflows where a top-side electrical connection is set on a sensor (e.g., CMOS). Figures 3A to 3F A portion of a flow cell 300 is depicted, including a substrate 310 and a sensor 320, the sensor including an active surface 330 having nanopores 340. This portion of the flow cell 300 also includes electrical contacts 350 (e.g., bonding pads, contact pads, bump pads) on the top side of the sensor 320. [Go to...] Figure 3A In one example, sensor 320 is fabricated for use within a flow cell by removing a top oxide layer from active surface 330, which can be achieved using RF cleaning etching to remove (e.g., aluminum (Al)) oxide layers. Figure 3B As shown, the seed layer 360 is sputtered onto the active surface 330 and the electrical contact 350. This sputtering of the seed layer 360 can be understood as a macroscopic layer because it is sputtered over the entire top surface of the sensor 300. The seed layer may be composed of materials including, but not limited to, titanium-tungsten (TiW), copper (Cu), titanium-copper (TiCu), and / or titanium (Ti).

[0075] like Figure 3C As shown, to protect the active surface 330 and the nanopores 340 during further processing, a photoresist 370 is patterned on the active surface 330. In this example, the photoresist 370 protects the nanopores during the formation of the protective layer 380 on the contact 350. This protective layer 380 may be electroplated. As explained herein, a portion of this protective layer 380 achieves electrical connection with the contact. As stated above, existing methods and techniques for forming contacts may pose challenges to the functionality of the active surface 330 of the wafer 320, including but not limited to the nanopores.

[0076] A photoresist layer 370 is patterned to form a window 375, which in some examples is wider than the electrical contact 350. For example... Figure 3D As shown, a protective (metal) layer 380 is then electroplated onto the seed layer 360 above the contact layer 350. The protective layer 380 may be composed of materials including, but not limited to, gold (Au), platinum (Pt), copper (Cu), and nickel (Ni). After electroplating, the photoresist 370 can be removed from the active surface 330, such as... Figure 3EAs shown in the diagram. Removal of photoresist 370 may include, but is not limited to, using ultraviolet (UV) light to decompose the cross-linked portions of the photoresist, and removing the photoresist by applying a developer to the bare substrate. In some examples of this process, bumps 395 have been formed by electroplating (e.g., Figures 3D to 3F When this process is performed, the photoresist is not removed, and the bump can be used for wire bonding contact 350. However, as shown in this example, in Figures 3E to 3F In this process, a portion of both photoresist 370 and seed layer 360 were removed. For example... Figure 3F As shown, although the seed layer 360 is removed below the photoresist 370, the seed layer remains between the protective layer 380 and the contact 350 because it forms the protective layer 380 on the surface of the contact 350 by adding the seed. In addition to any photoresist layers mentioned herein, this photoresist 370 layer can also be removed, for example, by a combination of ultraviolet (UV) light and a solvent called a developer. For example, UV light is applied to decompose the cross-linked portions of the photoresist, and the photoresist is removed by swelling it using a solvent (e.g., a developer). Meanwhile, the seed layer 360 can be removed, for example, by wet etching (e.g., hydrogen peroxide).

[0077] As mentioned above, existing methods and techniques for forming contacts can pose challenges to electrical connectivity on wafer surfaces. Electroplated bumps 395 mitigate this problem because they are resistant to further processes performed to fabricate the active surface 330 of the sensor 320, such as... Figure 4 As shown. These bumps 395 can be perceived as flanges because although the contact 350 is covered by the electroplated layer 312, the flange 313 is formed in the outer portion of the window 375. Therefore, the protective layer 380 formed over the area of ​​the sensor 320 (wafer) having the electrical contact 350 includes the flange 313 forming a wall on the outer portion of the window 375 and the layer 312 over the inner portion of the window 375.

[0078] Figure 4 This illustration compares the durability of sensor 400 under two different conditions. In the case depicted on the left, the sensor is treated with the aforementioned coating and polishing, while in the case depicted on the right, procedures such as... are performed within the sensor. Figures 3A to 3F The process described herein causes the electrical contacts on the sensor to include an electroplated layer (e.g., Figures 3D to 3F ,380). Figure 4 Two alternative workflows are described, in which sensor 400 is protected by electroplated bumps, such as, for example Figures 3A to 3F As described herein, and in which such protection is not provided to sensor 400. Figure 4The workflow is highlighted by utilizing portion 429 of sensor 400. As described above, the aspects discussed herein are used to retain the functionality of the sensor when forming the top-side contact.

[0079] As mentioned above, Figure 4 The workflow on the left illustrates how certain aspects of existing flow cell manufacturing processes can affect the electrical integrity of contacts on the top side of the wafer. Therefore, turning first to the workflow illustrated on the left, a sensor 400 having at least one top-side contact 450 and an active surface 430 is coated without electrical contact (pad) protection (402). In some examples, portions of the die or sensor structure are coated with a polymer material 442. The polymer material can be, for example, a gel-based material, such as a polyacrylamide gel coating, including, for example, poly(N-(5-azidoacetamidopentyl)acrylamide-co-acrylamide-co-acrylonitrile) (“PAZAM”). In one example, the die or sensor structure 429 includes at least one nanopore 440 at the surface (active surface 430), and the coating is present at the bottom and / or sidewall portions of the nanopore 440. During the coating process (405), the coating is applied to the electrical contact 450. After the coating is applied (405), at least a portion of the coating is polished (415). Figure 4 As shown, the coating (405) and subsequent polishing (415) can cause damage to the electrical contact 450. Since the electrical contact can be made of aluminum, the damage can be aluminum damage. Such damage, if it enters from the top side of the sensor 400, can render the electrical contact unusable.

[0080] As previously described, the workflow on the right illustrates various aspects of the examples illustrated and disclosed herein for preserving the electrical integrity of contacts formed on the wafer top side. Therefore, turning now to the workflow on the right, in the case of electrical contact (pad) protection (402), such as, for example... Figures 3A to 3F As shown, and also discussed in certain other variations herein, a sensor 400 (including portions of sensor 429) having at least one top-side contact 450 and an active surface 430 is protected (406) by an electroplated metal layer 480 (e.g., gold (Au), platinum (Pt), copper (Cu), and / or nickel (Ni)). Although not illustrated, the metal layer 480 includes the aforementioned bumps that can be used to engage the electrical contact 450 via the top-side leads of the sensor 400. Figure 4As depicted, in some examples, portions of the die or sensor structure are coated with a polymer material 442 (416). As described above, the polymer material may be, for example, a gel-based material, such as a polyacrylamide gel coating, including, for example, poly(N-(5-azidoacetamidopentyl)acrylamide-co-acrylamide-co-acrylonitrile) (“PAZAM”). In this example, the die or sensor structure 429 includes at least one nanopore 440 at a surface (active surface 430), and the coating is present at the bottom and / or sidewall portions of the nanopore 440. During the coating process (416), the coating is applied over the electrical contact 450 and over the protective layer 480 on the electrical contact 450. After the coating is applied (416), at least a portion of the coating is polished (426). Because the electrical contact 450 has the protective layer 480, damage to the contact 450 is minimized and / or prevented, such that the top-side wiring of the sensor 400 is achieved via the protective layer 480 (which is conductive). Those skilled in the art will understand that various aspects from some examples in this disclosure, such as Figures 3A to 3F The reference element, for illustrative purposes only and not to impose any limitation, incorporates a seed layer 360 and photoresist 370 to mitigate potential damage to various parts of the wafer during processing. These additional protective aspects discussed in some examples are for illustrative purposes only. Figure 4 Omitted in .

[0081] like Figures 3D to 3F As previously shown, the protective layer 380 over the region of the sensor 320 (wafer) having electrical contacts 350 includes a flange 313 forming a wall on the outer portion of the window 375 and a layer 312 over the inner portion of the window 375. Figure 5 These aspects are illustrated in the figure, which is a contour view of a sensor (e.g., CMOS) 500 having electrical contacts 550. In this example, a protective electroplating layer 512 and a formed flange 513 form bumps 595 (e.g., gold (Au), platinum (Pt), copper (Cu) and / or nickel (Ni)) on the electrical contacts 550 (e.g., bump pads) of the wafer (sensor 500). Figure 5 Depicting and Figure 3F Similar structures, but viewed from different angles, i.e. three-dimensional contours, make the morphology of the wafer easier to see. Figure 5 An electrical contact 550 (e.g., a bump pad) is illustrated, having an electroplated layer 512 and a flange 513 forming a wall structure surrounding the electrical contact 550. In this example, the electrical contact 550 is plated with gold (Au), and the active surface 530 of the sensor 500, including nanopores (not visible in this figure), is not plated with a protective layer 580. If the electroplated protective layer (e.g., Figures 3D to 3FIf 380) is coated on the active surface 530, the resulting damage to the active surface 530 will make the sensor unsuitable for imaging, flow cells, etc. Figure 6 The example illustrates this problem.

[0082] Figure 6 A view is provided of the active surface 630 of sensor 600, damaged by a deposited material used to provide protection and contact to the electrical contacts 650 on the top side surface of sensor 600. In this example, gold (Au) is the material used for the coating. The deposition of this material on the active surface 630 of the wafer, including sensor 600, impairs the sensor's function. A bump 695, formed during the electroplating process, is also visible in this figure, providing connectivity to the electrical contacts 650.

[0083] As mentioned above, Figures 3A to 3F Examples of processes for adding a protective layer to electrical contacts are illustrated, which preserve the contacts during the fabrication of the active surface of the wafer (sensor or detector) but also achieve electrical connection to the top side of the wafer. Figures 7A to 7E as well as Figures 8A to 8E Other examples of methods and processes for achieving top-side bonding with a wafer based on implementing metal bumps on electrical contacts are illustrated. Figures 3A to 3F The process is the same as shown in the diagram. Figures 7A to 7E as well as Figures 8A to 8E The process illustrated provides the benefit of maintaining wafer functionality (when utilized, e.g., in a flow cell), including but not limited to: 1) preserving electrical connectivity on the wafer surface; and 2) preserving the functionality of the wafer's active surfaces, including but not limited to nanopores. As mentioned above, certain existing fabrication and manufacturing processes can pose challenges to forming electrical contacts on the top side of the wafer.

[0084] Figures 3A to 3F as well as Figures 7A to 7E The differences lie in the placement of the seed layers 360 and 760, and the placement and number of the photoresist layers 370, 770, and 772. However, as explained herein, while including these structural variations to illustrate the flexibility of fabricating contacts on the top side of a wafer without introducing any limitations, in both examples these aspects are used to protect both the contacts and the active surface during wafer fabrication or fabrication (e.g., in a flow cell). References Figures 7A to 7E The image depicts a portion of a sensor 700 (e.g., a CMOS), which includes an electrical contact 750 and an active surface 730, as well as at least one nanopore 740. In this example, the sensor 700 is oxidized (e.g., oxidative cleaning), and then a photoresist 770 is applied to the active surface 730 of the sensor 700 and the photoresist 770 is patterned, as opposite to that on a seed layer, such as on... Figures 3A to 3FAs completed in the process. A seed layer 760 (e.g., titanium-tungsten (TiW), copper (Cu), titanium-copper (TiCu), and / or titanium (Ti)) is formed on the surface of the sensor 700, which includes a photoresist 770 and electrical contacts 750, such as... Figure 7B As shown in the diagram. In another example, instead of oxidizing the sensor 700 before the photoresist 770, the photoresist 770 and seed layer 760 are formed and then the sensor is oxidized, which means that the metal (which may be aluminum (Al)) including the electrical contact 750 is oxidized.

[0085] As mentioned above, with Figures 3A to 3F Compared to the example shown, in Figures 7A to 7E In the middle, photoresist 770 is located below the seed layer 760, and... Figures 3A to 3F Conversely, the seed layer 360 lies beneath the photoresist 370. This difference in the process of forming contacts on the top side of the wafer can be used to protect the active surfaces of the wafer during processing. For example, in some cases, removing these layers can be challenging based on the materials used in the photoresists 370, 770 and / or the seed layers 360, 760, as shown in Figure 3. To overcome any material compatibility issues, such as... Figure 7B As shown, when patterning the photoresist, and before applying the second photoresist layer 772, the photoresist 770 is applied at approximately the same time as the seed layer 760. Even though the seed layer 760 does not contact the active surface 730 of the sensor 700 (as well as the layer formed on the active surface 330)... Figure 3A Compared to seed layer 360, seed layer 760 will also become a high-speed electrical signal highway. (More details to follow...) Figure 8B Similar configurations are discussed, in which these highways for electrical signals are formed via a seed layer 860. Despite these non-limiting variations in configuration, implementing at least one photoresist layer above the active surface of the sensor helps preserve the functionality of the wafer's active surface, including but not limited to nanopores.

[0086] Turning Figure 7C As described above, the second photoresist layer 772 is formed on the seed layer 760, and the second photoresist layer 772 is patterned. Figure 7D An example of an electroplated protective layer 780 (e.g., gold (Au), platinum (Pt), copper (Cu), and / or nickel (Ni)) is illustrated, comprising a layer 712 over bumps 795 and contacts 750. The protective layer 780 may be composed of materials including, but not limited to, gold (Au), platinum (Pt), copper (Cu), and nickel (Ni). In this example, after electroplating is complete, the second photoresist 772 is removed, such as... Figure 7EAs shown, this includes the portion of seed layer 760 above active surface 730 and other photoresist layers 770. As previously mentioned, the photoresist can be removed using methods including, but not limited to, using ultraviolet (UV) light to decompose the cross-linked portions of the photoresist, and removing the photoresist by applying a developer to the die. The portion of seed layer 760 above contact 750 connects the protective layer 780 to contact 750 by adding a seed. In some examples, the portion of seed layer 760 removed is removed using wet etching (e.g., hydrogen peroxide). Figure 7E As shown, the remaining structure is sensor 700 after all specific layers have been removed. This sensor can be coated and polished, and then wire bonding can be formed from electrical contacts 750 to electrical contacts outside the flow cell and / or at another location within the flow cell. A protective (conductive) layer 780 enables wire bonding to contacts 750. Figures 3A to 3F The example shown is in Figure 7E In this process, the seed layer 760 retains the electrical connection function on the wafer surface by adding seed crystals to the protective layer 780 of the contact 750. Figures 7A to 7D In this context, the seed layer 760 can be understood as a macroscopic photoresist layer 770, which is patterned over the entire active surface 330 and electrical contact 750, while the second photoresist layer 772 can be understood as a microscopic layer, as it is patterned around the electrical contact 750 (e.g., bonding pads).

[0087] and Figures 3A to 3F as well as Figures 7A to 7E The example shown is the same. Figures 8A to 8E The aspects of the examples illustrated also retain the electrical connectivity functionality on the wafer surface; and 2) retain the functionality of the active surface of the wafer, including but not limited to nanopores. (See reference) Figures 8A to 8E This depicts a portion of a sensor 800 (e.g., CMOS). In Figure 8A In the sensor 800, a portion includes an electrical contact 850, an active surface 830, and at least one nanopore 840. Figure 8A Move to Figure 8B Not only does it oxidize (e.g., oxidize and clean) the sensor 800 and the seed layer 860 (e.g., titanium-tungsten (TiW), copper (Cu), titanium-copper (TiCu), and / or titanium (Ti)), which is formed as a macroscopic layer on the sensor including the active surface 830 and electrical contacts 850 (e.g., bonding pads), but it also... Figure 8B As shown, a first photoresist layer 884 is applied and patterned on the electrical contact 850. In this example, the portion of the seed layer 860 not beneath the photoresist 884 is stripped. Then, the photoresist 884 is stripped (protected), such that... Figure 8CAs shown, the seed layer 860 remains above the contact 850 (e.g., bonding pad) due to the minimization and / or prevention of removal of the photoresist 884. Figures 3A to 3F as well as Figures 7A to 7E Compared to the example shown, in such Figures 8B to 8D In this example illustrated, before adding protective layer 880 (e.g., Figure 8D ), removing the portion of the seed layer 860 above the active surface 830 (e.g., Figures 8B to 8C This protective layer 880 can be electroplated. After removing the portion of the seed layer 860 above the active surface 830, it remains as follows. Figure 8C A portion of the seed layer 860 shown will become a highway 832 (connectivity) of the metal protective layer 880 (e.g., gold (Au), platinum (Pt), copper (Cu) and / or nickel (Ni)). Figure 8E (832). In some examples, the seed layer 860 on the active surface 830 may or may not be removed using an etchant that preserves the nanopores 840.

[0088] Return to Figure 8B The portion of the first photoresist layer 884 and the seed layer 860 applied to the contact 850 above the contact helps retain this portion of the seed layer 860, thus it can be used, for example, as a connection to the seed metal protective layer 880 (e.g., Figure 8D The metal protective layer of the high-speed highway 832 will include bumps that enable electrical coupling to the top side of the sensor 800. This helps maintain electrical connectivity on the wafer surface.

[0089] refer to Figure 8C Maintaining the function of the nanopores 840 on the active surface 830 is also addressed through certain aspects of this example. Furthermore... Figure 8C As shown, a second photoresist layer 870 is formed on the active surface 830 of the sensor 800. Figure 8D As shown, this second photoresist layer 870 is patterned (developed) before electroplating the sensor 800 to add a metal protective layer 880, which will include bumps that realize electrical coupling to the top side of the sensor 800. Figure 8E The higher portion of the electroplated layer 880 is visible, and Figure 8E The formed flange 813 is depicted, which is also... Figure 5 Examples (e.g.) Figure 5 (513). For example Figures 8D to 8EAs shown, photoresist 870 has been stripped. Photoresist can be removed using methods including, but not limited to, using ultraviolet (UV) light to decompose the cross-linked portions of the photoresist, and removing the photoresist by applying a developer to the die. In some examples, any portion of the seed layer 860 that remains after the initial removal layer and is not covered by the bumps of the metal protective layer 880 is removed. For example, if any portion of the seed layer 860 with retaining protruding bumps is present, it is removed.

[0090] Figure 9 Various examples of certain aspects of the methods and processes disclosed herein are also illustrated with reference to certain examples, but the illustrations of parts of sensor 900 are provided from different advantageous positions or angles to illustrate the placement of the layers. As with the earlier examples, in Figure 9 In this example, various aspects make top-side connection to the wafer possible, and the functionality of the active surface is preserved during contact formation. In this example, photoresist 970 is formed on the region of sensor 900 including active surface 930, but photoresist 970 is not formed on electrical contact 950 (e.g., bonding pad). The photoresist 970 is patterned. The photoresist 970 is used in part to retain the active surface in another aspect. Then, (from Figure 9 A seed layer (e.g., titanium-tungsten (TiW), copper (Cu), titanium-copper (TiCu), and / or titanium (Ti)) is sputtered onto sensor 900, and seeding is applied to portions of sensor 900 not covered by photoresist 970 for application of electroplating protective layer 980, which includes bumps, i.e., the aforementioned flanges (not visible from this perspective). In this example, prior to applying this protective layer 980, a second photoresist layer is applied and patterned, the second photoresist layer creating paths between electrical contacts. Figure 9 This additional layer is not depicted. The sensor 900 is electroplated and a protective layer 980 is formed by patterning the photoresist near the electrical contact 950. After electroplating is complete, the seed layer 960 can be removed in areas where the protective layer 980 does not cover it. Figure 9 As shown, electrical contact 950 is connected to additional contact 917 via lead bonding 923 through protective layer 980. Then, as... Figure 4 As explained in the discussion, the sensor is coated and polished so that it can be used in a variety of devices, including but not limited to flow cells.

[0091] Figure 10 and Figure 11 This is an example workflow illustrating methods for manufacturing and / or fabricating sensors with top-side electrical contacts. For ease of understanding and without implying any limitation, reference is made throughout the description of these examples. Figures 3A to 3F , Figures 7A to 7E as well as Figures 8A to 8E This involves various aspects of the workflow. Therefore, some examples of the components of the workflow can be more easily visualized.

[0092] First refer to Figure 10 In this exemplary workflow 1000, bumps (1010) are formed on the surface of one or more electrical contacts. The bumps may be made of various materials, including but not limited to gold (Au), platinum (Pt), copper (Cu), and / or nickel (Ni). These electrical contacts (e.g., 350, 750, 850) are capable of contacting the upper surface of a die (e.g., CMOS) (e.g., 300, 700, 800), wherein the die is oriented on a substrate. The electrical contacts may be (e.g., Al) bonding pads. These electrical contacts (e.g., 350, 750, 850), which may or may not be bonding pads, include, but are not limited to, die bonding pads, and in some examples, these electrical contacts are adjacent to active surfaces (e.g., 330, 730, 830). The active surfaces include nanopores (e.g., 340, 740, 840). The nanopores may or may not form a nanopore array.

[0093] Additional electrical contacts (e.g., substrate bonding pads) are coupled to one or more electrical contacts via a portion of bumps (e.g., 313, 513, 713, 813) on the surface of one or more electrical contacts, thereby forming a wire-joined connection (1020) by wire-joining each additional electrical contact lead to one of the one or more electrical contacts (e.g., 350, 750, 850). The die is coated with a polymer material (1030). A portion of the coating is polished (1040).

[0094] Figure 11 This is a more detailed example of the workflow 1100 for forming bumps (e.g., Figure 10 , 1010). In this example, the method includes forming a bump, which includes removing a top oxide layer from the upper surface of the die (1112). The method also includes forming a seed layer (e.g., 360, 760, 860) (1114) on the upper surface of the die (e.g., sputtering material on the upper surface of the die). This example then includes applying a photoresist (e.g., 370, 770, 870) on an active surface (e.g., 330, 730, 830) of the die that is part of the upper surface and patterning the photoresist such that the seed layer is exposed on the unpatterned portion of the upper surface of the photoresist (1115). In some examples, forming a bump involves electroplating a metal layer (e.g., 380, 780, 880) on the exposed seed layer, which includes applying a metal layer on electrical contacts (e.g., 350, 750, 850). Figure 11 Examples then include removing the photoresist (1117). Finally, in some examples, the method includes removing the portion of the seed layer above the active surface (1118).

[0095] The seed layer may or may not be removed from the active surface using an etchant that preserves nanopores. The seed layer may or may not be a metal, including but not limited to titanium tungsten (TiW), copper (Cu), titanium copper (TiCu), and / or titanium (Ti).

[0096] Some examples involve layering a photoresist layer on the active surface of the die prior to forming a seed layer, the initial photoresist being patterned on the active surface of the die. Figure 10 (not shown in the image) (For example, Figure 7B , 770). In this example, the second photoresist layer (e.g., Figure 7C (772) can be patterned on the seed layer. For example... Figures 7D to 7E As shown, two photoresist layers 772 and 770 and a seed layer 760 are removed above the active surface 730.

[0097] Some examples involve two photoresist layers, but one of the photoresist layers is patterned on the electrical contact while the other is patterned on the active surface. Figures 8A to 8E One example of these types is shown.

[0098] In some examples of the methods described herein, the method includes forming bumps on the surfaces of one or more electrical contacts, wherein the one or more electrical contacts are capable of contacting an upper surface of a die, wherein the die is oriented on a substrate, and wherein the electrical contacts include bonding pads. The method may also include coupling additional electrical contacts to the one or more electrical contacts, wherein the coupling includes wire-bonding each of the additional electrical contacts to one of the one or more electrical contacts capable of contacting the upper surface of the die via a portion of the bumps on the surfaces of the one or more electrical contacts, thereby forming a wire-bonded connection.

[0099] In some examples, the die is oriented on the substrate such that a first space is defined in a cavity at a first edge adjacent to the upper surface of the die, and a second space is defined in a cavity at a second edge adjacent to the upper surface of the die, wherein the bottom fill layer includes a cavity between the lower surface of the die and the substrate.

[0100] In some examples, one or more electrical contacts comprise aluminum.

[0101] In some examples, the die includes complementary metal-oxide-semiconductor (CMOS).

[0102] In some examples, the active surface of the die includes a portion of the upper surface of the die comprising nanopores, one or more electrical contacts adjacent to the active surface, and forming the bump includes removing a top oxide layer from the upper surface of the die. The method may also include forming a seed layer on the upper surface of the die. The method may further include applying a photoresist to the active surface of the die and patterning the photoresist, wherein the seed layer is exposed on a portion of the upper surface without the patterned photoresist. The method may further include electroplating a metal layer on the exposed seed layer, wherein the electroplating includes applying the metal layer on one or more electrical contacts.

[0103] In some examples, the method also includes forming an initial photoresist on the active surface of the wafer and patterning the initial photoresist before forming the seed layer.

[0104] In some examples, the method also includes removing the photoresist from a portion of the upper surface.

[0105] In some examples, the active surface comprises an array of nanopores. The method may also include removing the seed layer from the active surface by using an etchant that retains the nanopore array.

[0106] In some examples, the method also includes removing the initial photoresist.

[0107] In some examples, removing photoresist involves using ultraviolet (UV) light to break down the cross-linked portions of the photoresist and removing the photoresist by applying a developer to the bare film.

[0108] In some examples, forming a seed layer involves sputtering material onto the upper surface of the die.

[0109] In some examples, the seed layer is made of metal.

[0110] In some examples, the material including the seed layer is selected from the group consisting of: titanium tungsten (TiW), copper (Cu), titanium copper (TiCu), and titanium (Ti).

[0111] In some examples, the material used for the bumps is selected from the group consisting of gold (Au), platinum (Pt), copper (Cu), and nickel (Ni).

[0112] In some examples, the method also includes coating the bare die with a polymer material and polishing at least a portion of the coating.

[0113] In some examples, one or more additional electrical contacts include substrate bonding pads, and one or more electrical contacts include die bonding pads.

[0114] In some examples, the bare wafer includes coated and polished nanopores.

[0115] Some examples of the devices described herein may include a substrate comprising a die, wherein the die is oriented on the substrate, including one or more electrical contacts with bonding pads oriented on an upper surface of the die, wherein a portion of the upper surface of each of the one or more electrical contacts is delaminated with a coating including metal bumps. The device may also include one or more additional electrical contacts, each of which is electrically coupled to at least one of the one or more electrical contacts via wire bonding through a portion of a metal bump on at least one contact. The device may also include fluid flow channels on an active surface of the die, the active surface of the die including a portion of a nanopore on the upper surface of the die, with one or more electrical contacts adjacent to the active surface.

[0116] In some examples, the metal coating is selected from the group consisting of gold (Au), platinum (Pt), copper (Cu), and nickel (Ni).

[0117] In some examples, the die includes complementary metal-oxide-semiconductor (CMOS).

[0118] Some examples of the methods described herein include forming bumps on the surface of one or more bonding pads, wherein the one or more bonding pads are capable of contacting an upper surface of a sensor utilized in a flow cell, wherein a portion of the top surface of the sensor includes an active surface, and wherein the one or more bonding pads are positioned adjacent to the active surface. Forming may include removing a top oxide layer from the upper surface of the sensor. The method may also include forming a seed layer on the upper surface of the sensor. The method may further include applying a photoresist to the active surface of the sensor and patterning the photoresist, wherein the seed layer is exposed on a portion of the upper surface without the patterned photoresist. The method may further include electroplating a metal layer on the exposed seed layer, wherein the electroplating includes applying a metal layer on one or more bonding pads.

[0119] In some examples, the method further includes forming an initial photoresist on the active surface of the sensor and patterning the initial photoresist before forming the seed layer.

[0120] In some examples, the method also includes removing the photoresist from a portion of the upper surface.

[0121] In some examples, the active surface comprises an array of nanopores, and the method further includes removing the seed layer from the active surface by utilizing an etchant that retains the nanopore array.

[0122] In some examples, the method also includes removing the initial photoresist from the active surface of the sensor.

[0123] In some examples, removing photoresist involves using ultraviolet (UV) light to break down the cross-linked portions of the photoresist and removing the photoresist by applying a color developer to the sensor.

[0124] In some examples, forming a seed layer involves sputtering material onto the upper surface of the sensor.

[0125] In some examples, the material including the seed layer is selected from the group consisting of: titanium tungsten (TiW), copper (Cu), titanium copper (TiCu), and titanium (Ti).

[0126] In some examples, the material used for the bumps is selected from the group consisting of gold (Au), platinum (Pt), copper (Cu), and nickel (Ni).

[0127] In some examples, the method includes coating the bare die with a polymer material and polishing at least a portion of the coating.

[0128] In some examples, the method further includes using bumps on the bonding pads to couple additional electrical contacts to the bonding pads, wherein the coupling includes bonding each additional electrical contact lead in the additional electrical contacts to one of the bonding pads on the surface of the sensor via the bumps, thereby forming a wire-bonded connection.

[0129] In some examples, the sensor includes a complementary metal-oxide-semiconductor.

[0130] In some examples, the active surface includes coated and polished nanopores.

[0131] Examples of the methods disclosed herein include: forming bumps on the surface of one or more bonding pads, wherein the one or more bonding pads are capable of contacting an upper surface of a sensor utilized in a flow cell, wherein a portion of the top surface of the sensor includes an active surface, and wherein the one or more bonding pads are positioned adjacent to the active surface. Forming may include removing a top oxide layer from the upper surface of the sensor. The method may also include forming a seed layer on the upper surface of the sensor, wherein a first portion of the seed layer is formed on the one or more bonding pads and a second portion of the seed layer is formed on the active surface; applying a first photoresist on the one or more bonding pads and patterning the first photoresist. The method may also include removing the second portion of the seed layer. The method may also include applying a second photoresist on the active surface of the sensor and patterning the second photoresist. The method may also include electroplating a metal layer on the first portion of the seed layer, wherein electroplating includes applying a metal layer on the one or more bonding pads. The method may include stripping a second photoresist. The method may include stripping a segment of the first portion of the seed layer, wherein the segment is not covered by the metal layer.

[0132] In some examples, the method further includes using bumps on the bonding pads to couple exposed electrical contacts to the bonding pads, wherein the coupling includes bonding each exposed electrical contact lead to one of the bonding pads on the surface of the CMOS, thereby forming a wire-bonded connection.

[0133] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible embodiments of systems, methods, and computer program products according to various examples of specific implementations of the invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of instructions, including one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions indicated in the blocks may occur in a different order than indicated in the figures. For example, two blocks shown consecutively may actually be executed substantially simultaneously, or these blocks may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified function or action or executes a combination of dedicated hardware and computer instructions.

[0134] The terminology used herein is for the purpose of describing particular examples only and is not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms “an,” “a,” and “the” are intended to also include the plural forms. It should also be understood that, when used in this specification, the terms “comprising” and / or “including” specify the presence of the stated feature, integer, step, process, operation, element, and / or component, but do not exclude the presence or addition of one or more other features, integers, steps, processes, operations, elements, components, and / or groups thereof.

[0135] The corresponding structures, materials, actions, and all means or steps plus equivalents of functional elements (if any) in the following claims are intended to include any structure, material, or action for performing a function in combination with other claimed elements of the specific claim. Descriptions of one or more examples have been presented for illustrative and descriptive purposes, but are not intended to be exhaustive or limiting to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. The examples were chosen and described in order to best explain the various aspects and practical applications, and to enable others skilled in the art to understand the various examples with various modifications suitable for the particular intended use.

[0136] It should be understood that all combinations of the foregoing concepts and the additional concepts discussed in more detail below (assuming such concepts do not contradict each other) are contemplated as part of the subject matter disclosed herein to achieve at least the beneficial effects described herein. Specifically, all combinations of the claimed subject matter appearing at the end of this disclosure are contemplated as part of the subject matter disclosed herein. It should also be understood that terms expressly adopted herein that may also appear in any disclosure incorporated by reference should be given the meaning most consistent with the specific concepts disclosed herein.

[0137] This written description uses examples to disclose the subject matter and also enables any person skilled in the art to practice the subject matter, including making and using any device or system and performing any combined methods. The patentable scope of the subject matter is defined by the claims and may include other examples that would occur to a person skilled in the art. Such other examples are intended to fall within the scope of the claims if they have structural elements that are indistinguishable from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

[0138] It should be understood that the above description is intended to be illustrative and not restrictive. For example, the above examples (and / or aspects thereof) may be used in combination with each other. Furthermore, many modifications may be made to adapt a particular situation or material to the teachings of the various examples without departing from the scope of the various examples. While the dimensions and types of materials described herein are intended to define parameters of the various examples, they are by no means restrictive and are provided only by way of example. Many other examples will be apparent to those skilled in the art upon reviewing the above description. Therefore, the scope of the various examples should be determined by reference to the appended claims and the full scope of their equivalents. In the appended claims, the terms “comprising” and “therein” are used as common English equivalents of the corresponding terms “including” and “wherein”. Furthermore, in the following claims, the terms “first,” “second,” and “third,” etc., are used merely as labels and are not intended to impose numerical requirements on their objects. The term “based on” in this document covers relationships in which elements are partially based as well as relationships in which elements are completely based. The term “defined” in this document covers relationships in which elements are partially defined as well as relationships in which elements are completely defined. Furthermore, the limitations of the following claims are not written in a means-plus-function format and are not intended to be interpreted based on paragraph 6 of 35 U.S.SC § 112, unless and until these claims expressly use the phrase "means for..." followed by a functional statement without any other structure. It should be understood that not all such objects or advantages described above can necessarily be achieved according to any particular example. Therefore, for example, those skilled in the art will recognize that the systems and techniques described herein can be implemented or performed in a manner that achieves or optimizes one or more advantages taught herein without necessarily achieving other objects or advantages that may be taught or suggested herein.

[0139] Although the subject matter has been described in detail with reference to only a limited number of examples, it should be readily understood that the subject matter is not limited to such disclosed examples. Rather, the subject matter may be modified to incorporate any number of variations, alterations, substitutions, or equivalent arrangements not previously described but equivalent in substance and scope to the subject matter. Furthermore, while various examples of the subject matter have been described, it should be understood that aspects of this disclosure may include only some of the examples described. Additionally, while some examples are described as having a certain number of elements, it should be understood that the subject matter can be practiced with fewer or more than a certain number of elements. Therefore, the subject matter should not be considered limited to the foregoing description but only to the scope of the appended claims.

Claims

1. A wire bonding method, the method comprising: A bump is formed on the surface of one or more electrical contacts, wherein the one or more electrical contacts are capable of contacting the upper surface of a die, wherein the active surface of the die includes a portion of the upper surface of the die including nanopores, wherein the one or more electrical contacts are adjacent to the active surface, wherein the electrical contacts include bonding pads, and forming the bump includes: Remove the top oxide layer from the upper surface of the bare die; A seed layer is formed on the upper surface of the bare wafer; A photoresist is applied to the active surface of the bare wafer and the photoresist is patterned, wherein the seed layer is exposed on a portion of the upper surface without the patterned photoresist; and Electroplating a metal layer on the exposed seed layer, wherein the electroplating includes applying the metal layer on the one or more electrical contacts; and Additional electrical contacts are coupled to the one or more electrical contacts, wherein the coupling includes wire-connecting each of the additional electrical contacts to one of the one or more electrical contacts capable of contacting the upper surface of the bare die via a portion of the bump on the surface of the one or more electrical contacts, thereby forming a wire-connected connection.

2. The method of claim 1, wherein the die is oriented on the substrate such that a first space is defined in a cavity adjacent to a first edge of the upper surface of the die, and a second space is defined in a cavity adjacent to a second edge of the upper surface of the die, and wherein the bottom filler layer includes a cavity between the lower surface of the die and the substrate.

3. The method according to any one of claims 1 to 2, wherein the one or more electrical contacts comprise aluminum.

4. The method according to any one of claims 1 to 2, wherein the die comprises complementary metal-oxide-semiconductor (CMOS).

5. The method according to claim 1, further comprising: Before forming the seed layer, an initial photoresist is formed on the active surface of the bare wafer and the initial photoresist is patterned.

6. The method according to claim 5, further comprising: Remove the photoresist.

7. The method of claim 6, wherein the active surface comprises a nanopore array, and the method further comprises: The seed layer is removed from the active surface by using an etchant that retains the nanopore array.

8. The method according to claim 7, further comprising: The initial photoresist is removed from the active surface of the bare die.

9. The method of claim 6, wherein removing the photoresist comprises using ultraviolet (UV) light to decompose the crosslinked portion of the photoresist and removing the photoresist by applying a developer to the bare film.

10. The method according to any one of claims 1 to 2, wherein forming the seed layer comprises sputtering material onto the upper surface of the bare wafer.

11. The method according to any one of claims 1 to 2, wherein the seed layer is made of metal.

12. The method according to any one of claims 1 to 2, wherein the material of the seed layer is selected from the group consisting of: titanium tungsten (TiW), copper (Cu), titanium copper (TiCu), and titanium (Ti).

13. The method according to any one of claims 1 to 2, wherein the material of the bump is selected from the group consisting of gold (Au), platinum (Pt), copper (Cu) and nickel (Ni).

14. The method according to claim 7 or claim 8, further comprising: The bare sheet is coated with a polymer material; as well as At least a portion of the coated polymer material is polished.

15. The method according to any one of claims 1 to 2, wherein the one or more additional electrical contacts include substrate bonding pads, and the one or more electrical contacts include die bonding pads.

16. The method according to any one of claims 1 to 2, wherein the bare wafer comprises coated and polished nanopores.

17. An apparatus including a substrate, wherein the substrate includes a die, wherein the die is oriented on the substrate, including one or more electrical contacts for bonding pads oriented on an upper surface of the die, and wherein a portion of the upper surface of each of the one or more electrical contacts is layered with a coating including metal bumps, wherein the metal bumps include an electroplated metal layer on an exposed portion of a seed layer formed on the upper surface of the die, the unexposed portion of the seed layer being patterned with photoresist; The device also includes: One or more additional electrical contacts, each of the one or more additional electrical contacts being electrically coupled to at least one of the one or more electrical contacts via a portion of the metal bump on at least one contact through a lead engagement; as well as Fluid flow channels on the active surface of the die, wherein the active surface of the die includes a portion of the upper surface of the die, including nanopores, wherein one or more electrical contacts are adjacent to the active surface.

18. The apparatus of claim 17, wherein the metal of the metal bump is selected from the group consisting of gold (Au), platinum (Pt), copper (Cu), and nickel (Ni).

19. The apparatus of any one of claims 17 to 18, wherein the die comprises complementary metal-oxide-semiconductor (CMOS).

20. A method for forming a bump, the method comprising: A bump is formed on the surface of one or more electrical contacts including bonding pads, wherein the bump on the bonding pads is configured to couple additional electrical contacts to the bonding pads, wherein the one or more electrical contacts are capable of contacting an upper surface of a sensor used in a flow cell, wherein a portion of the upper surface of the sensor includes an active surface, wherein the one or more bonding pads are positioned adjacent to the active surface, the formation comprising: Remove the top oxide layer from the upper surface of the sensor; A seed layer is formed on the upper surface of the sensor; A photoresist is applied to the active surface of the sensor and the photoresist is patterned, wherein the seed layer is exposed on a portion of the upper surface without the patterned photoresist; and A metal layer is electroplated on the seed layer, wherein the electroplating includes applying the metal layer on the one or more bonding pads.

21. The method according to claim 20, further comprising: Before forming the seed layer, an initial photoresist is formed on the active surface of the sensor and the initial photoresist is patterned.

22. The method according to any one of claims 21 to 21, further comprising: Remove the photoresist from the portion of the upper surface.

23. The method of claim 22, wherein the active surface comprises a nanopore array, the method further comprising: The seed layer is removed from the active surface by using an etchant that retains the nanopore array.

24. The method according to claim 21, further comprising: Remove the initial photoresist from the active surface of the sensor.

25. The method according to any one of claims 20 to 21, wherein removing the photoresist comprises using ultraviolet (UV) light to decompose the crosslinked portion of the photoresist and removing the photoresist by applying a color developer to the sensor.

26. The method according to any one of claims 20 to 21, wherein forming the seed layer comprises sputtering material onto the upper surface of the sensor.

27. The method according to any one of claims 20 to 21, wherein the material of the seed layer is selected from the group consisting of: titanium tungsten (TiW), copper (Cu), titanium copper (TiCu), and titanium (Ti).

28. The method according to any one of claims 20 to 21, wherein the material of the bump is selected from the group consisting of gold (Au), platinum (Pt), copper (Cu) and nickel (Ni).

29. The method according to claim 23, further comprising: The sensor is coated with a polymer material; as well as A portion of the coated polymer material is polished.

30. The method according to claim 29, further comprising: Additional electrical contacts are coupled to the bonding pads using the bumps on the bonding pads, wherein the coupling includes wire bonding of each additional electrical contact lead to one of the bonding pads on the surface of the sensor via the bumps, thereby forming a wire-bonded connection.

31. The method according to any one of claims 20 to 21, wherein the sensor comprises a complementary metal-oxide-semiconductor.

32. The method according to any one of claims 20 to 21, wherein the active surface comprises coated and polished nanopores.

33. A method for forming a bump, the method comprising: The bump is formed on the surface of one or more bonding pads, wherein the one or more bonding pads are capable of contacting an upper surface of a sensor used in a flow cell, wherein a portion of the upper surface of the sensor includes an active surface, wherein the one or more bonding pads are positioned adjacent to the active surface, and wherein the bump on the bonding pad is configured to couple additional electrical contacts to the bonding pad, the formation comprising: Remove the top oxide layer from the upper surface of the sensor; A seed layer is formed on the upper surface of the sensor, wherein a first portion of the seed layer is formed on one or more bonding pads and a second portion of the seed layer is formed on the active surface; Apply a first photoresist to one or more bonding pads and pattern the first photoresist; Remove the second portion of the seed layer; A second photoresist is applied to the active surface of the sensor and the second photoresist is patterned. Electroplating a metal layer on the first portion of the seed layer, wherein the electroplating includes applying the metal layer on the one or more bonding pads; Stripping the second photoresist; and Stripping a segment of the first portion of the seed layer, wherein the segment is not covered by the metal layer.

34. The method according to claim 33, further comprising: The exposed electrical contacts are coupled to the bonding pads using the bumps on the bonding pads, wherein the coupling includes bonding each of the exposed electrical contacts to a bonding pad on the surface of the sensor, thereby forming a wire-bonded connection.

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