Devices including optofluidic sensors with integrated photodiodes

Abstract

This disclosure relates to a device including an optofluidic sensor with an integrated photodiode. A "lab-on-a-chip" includes an optofluidic sensor and components for analyzing signals from the optofluidic sensor. The optofluidic sensor includes: a substrate; a channel at least partially defined by a portion of a first material layer on the substrate; input and output fluid reservoirs in fluid communication with the channel; at least a first radiation source coupled to the substrate, adapted to generate radiation in a direction toward the channel; and at least one photodiode adjacent to and below the channel.

Description

Technical Field

[0001] This disclosure generally relates to various embodiments of devices including optical fluid sensors having integrated photodiodes, and various methods of forming such devices. Background Technology

[0002] Optofluidics is a technological field that typically involves the use of microfluidics and optics. Various applications and products utilize optofluidics, such as displays, biosensors, lab-on-a-chip devices, lenses, molecular imaging tools, and energy sources. However, such optofluidic devices are often very expensive to manufacture, involving complex methods of packaging discrete components together, and resulting in relatively large devices that are not easily scalable. Summary of the Invention

[0003] The following is a simplified summary of the invention to provide a basic understanding of certain aspects of this disclosure. This summary is not an exhaustive overview of the disclosure. It is not intended to identify key or essential elements of the disclosure or to depict its scope. Its sole purpose is to present some concepts in a simplified form as a prelude to the specific embodiments discussed later.

[0004] This disclosure relates to various embodiments of devices including optofluidic sensors having integrated photodiodes and various methods of forming such devices. An exemplary device disclosed herein may include: a substrate; a channel formed on an upper surface of a first material layer and adapted to receive fluid therein, the first material layer being formed on the substrate, the channel being defined at least partially by at least a portion of the top surface of the first material layer formed on the substrate, and the walls of the channel being formed of a second material as a dielectric material. The device may further include an input fluid reservoir and an output fluid reservoir, wherein the channel is in fluid communication with the input fluid reservoir and the output fluid reservoir. In this example, the device may further include: a first radiation source operatively coupled to the substrate, wherein the first radiation source is adapted to generate radiation in a first direction toward the channel; and at least one first photodiode positioned below the channel.

[0005] In another example, the device may include: a substrate; a channel adapted to receive fluid therein, the channel being defined at least partially by at least an upper surface of a first material layer formed on the substrate, and the channel having a long axis and opposing first and second sides, the walls of the channel being formed of a second material as a dielectric material. The device may further include an input fluid reservoir and an output fluid reservoir, and the channel being in fluid communication with the input fluid reservoir and the output fluid reservoir and arranged to transfer fluid from the input fluid reservoir to the output fluid reservoir. A first radiation source is operatively coupled to the substrate, wherein the first radiation source may be adapted to generate radiation in a direction substantially perpendicular to the long axis of the channel. The device may have at least one waveguide structure extending from the first radiation source to the first side of the channel, wherein the at least one waveguide structure is formed of the second material and extends from the first radiation source to the first side of the channel. The at least one waveguide structure may be adapted to transmit radiation from the first radiation source to the first side of the channel. At least one first photodiode may be positioned adjacent to and vertically below the second side of the channel, and the at least one waveguide structure may further extend from the second side of the channel to the at least one first photodiode. A laterally exposed portion of the channel may be at least partially defined by the extent of the at least one waveguide structure along the long axis of the channel. In this laterally exposed portion, during operation, radiation from the first radiation source may pass through the first side of the channel, through the channel, and exit from the second side of the channel.

[0006] In a third example, the device may include an optofluidic sensor system comprising a substrate on which a first material layer is formed, an input fluid reservoir, an output fluid reservoir, and a channel formed on the upper surface of the first material layer. The channel may be in fluid communication with the input and output fluid reservoirs, and the walls of the channel may be formed of a second material serving as a dielectric material. The optofluidic sensor system may further include at least one radiation source operatively coupled to the substrate such that the at least one radiation source is in photonic communication with the channel. The at least one photodiode may be positioned below the channel such that the at least one photodiode receives radiation from the at least one radiation source and passes through the channel. The device may further include a processing system formed on the substrate and electrically communicated with the optofluidic sensor system. The processing system may also include at least one component electrically communicated with the at least one photodiode and responding to changes in the electrical parameters of the at least one photodiode. Attached Figure Description

[0007] This disclosure can be understood by referring to the following description in conjunction with the accompanying drawings, in which like reference numerals denote like elements, and wherein:

[0008] Figure 1-23 Various embodiments of an optical fluidic sensor with an integrated photodiode and various methods of forming such a device are shown. The figures are not drawn to scale.

[0009] While the subject matter disclosed herein is susceptible to various modifications and alternatives, specific embodiments thereof have been illustrated by way of example in the accompanying drawings and described in detail herein. However, it should be understood that the description of specific embodiments herein is not intended to limit this disclosure to the particular forms disclosed, but rather, this disclosure covers all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure as defined by the appended claims. Detailed Implementation

[0010] Various exemplary embodiments of this disclosure are described below. For clarity, not all features of an actual implementation are described in this specification. It will be understood, of course, that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as adhering to system-related and business-related constraints that will vary from one implementation to another. Furthermore, it will be understood that such development efforts can be complex and time-consuming, but will remain a routine task for those skilled in the art who benefit from this disclosure.

[0011] The subject matter will now be described with reference to the accompanying drawings. For illustrative purposes, various structures, systems, and devices are depicted only schematically in the drawings so as not to obscure this disclosure with details well known to those skilled in the art. However, the drawings are included to provide exemplary examples for describing and explaining this disclosure. Words and phrases used herein are to be understood and interpreted as having meanings consistent with the understanding of those skilled in the art. No specific definition of a term or phrase (i.e., a definition different from the common and usual meaning understood by those skilled in the art) is intended to imply through the consistent use of terms or phrases herein. Where a term or phrase is intended to have a particular meaning (i.e., a meaning other than that understood by those skilled in the art), such a particular definition will be explicitly set forth in the specification in a defining manner that directly and clearly provides the particular definition of the term or phrase. As will be apparent to those skilled in the art upon a complete reading of this application, the methods disclosed herein can be applied to a variety of products, including but not limited to logic products, memory products, etc. Various exemplary embodiments of the methods and devices disclosed herein will now be described in more detail with reference to the accompanying drawings. The various components, structures, and material layers described herein can be formed using a variety of materials and by performing a variety of known process operations (e.g., chemical vapor deposition (CVD), atomic layer deposition (ALD), thermal growth processes, spin coating, masking, etching, etc.). The thickness of these various material layers can also vary depending on the specific application.

[0012] In this specification, "insulating material" may include any suitable insulating material that can be used, which may include any suitable dielectric material. Furthermore, "dielectric material" may include, but is not limited to, any interlayer or intralayer dielectric material comprising inorganic dielectric materials, organic dielectric materials, or combinations thereof. Suitable dielectric materials may include, but are not limited to: silica materials, including carbon-doped silica materials; fluorinated silicate glass (FSG); organic polymer thermosetting materials; silicon carbide; SiCOH dielectrics; fluorine-doped silica; spin-coated glass; silsesquioxanes, including hydrogen silsesquioxane (HSQ), methyl silsesquioxane (MSQ), and mixtures or copolymers of HSQ and MSQ; benzocyclobutene-based polymer dielectrics; and any silicon-containing low-k dielectrics. Examples of spin-coated low-k films with SiCOH-type compositions using silsesquioxane chemistry include HOSP™ (available from Honeywell), JSR 5109 and 5108 (available from Japan Synthetic Rubber), Zirkon™ (available from Rohm and Haas division of Shipley Microelectricals), and porous low-k (ELk) materials (available from Applied Materials). Examples of carbon-doped silica materials or organosilanes include Black Diamond™ (available from Applied Materials) and Coral™ (available from Lam Research). An example of HSQ materials is FOx™ (available from Dow Corning).

[0013] Figure 1-23 Various embodiments of a device 10 including an optofluidic sensor with an integrated photodiode are shown, as well as various methods of forming such a device 10. In the embodiments, the device 10 may include a processing system formed on a substrate and electrically connected to the optofluidic sensor. Figure 1 These are simplified plan views and partial cross-sectional views of an exemplary embodiment of device 10. Device 10 may be fabricated in and on semiconductor substrate 12 (see [reference]). Figure 3 ). refer to Figure 1 In one exemplary embodiment, device 10 typically includes a first photodiode array 11, a second photodiode array 13, a waveguide structure such as a waveguide array 15, a channel 16, an input fluid reservoir 18, an output fluid reservoir 20, a first radiation source 34 adapted to generate first radiation 44 in a first direction toward the channel 16, and a second radiation source 38 adapted to generate second radiation 42 in a second direction toward the channel 16. In embodiments, such as Figure 1As shown, one or both of the first and second photodiode arrays 11, 13 may include one or more corresponding photodiodes 28, 30 in a material "buried" beneath a surface on which a channel 16 is formed. Figure 1 As shown, the channel 16 may have a longitudinal axis extending from the first end closest to the second radiation source 40 to the second opposite end closest to the output reservoir 20, the longitudinal axis being parallel to the centerline 16L of the channel 16 (see [reference]). Figure 2 The components are substantially collinear. In an embodiment, the first radiation 34 may be positioned to emit a first radiation 44 perpendicular to the centerline 16L, while the second radiation source 38 may be positioned to emit a second radiation 42 in a direction parallel to and / or along the centerline 16L. The channel 16 may be in fluid communication with the input fluid reservoir 18 and the output fluid reservoir 20, and the channel 16 may be adapted to receive fluid 22 therein. The lateral exposed portion 25 of the channel 16 may be defined at least partially by the extent of the waveguide array 15 along the long axis of the channel 16. Those skilled in the art will understand upon fully reading this application that the optofluidic sensor with integrated photodiode disclosed herein is used to analyze samples (e.g., DNA, RNA, viruses, proteins, etc.) (not shown) that may be present in the fluid 22 as they flow through the channel 16 of the device 10.

[0014] In one exemplary embodiment, device 10 can be used to measure the photon count of a fluorescence signal of a sample excited by one or both of radiation sources 34, 38, and compare the measurement with a reference value. Typically, during the sample analysis process, fluid 22 can be maintained under near-steady-state conditions, and the sample (DNA, RNA, virus, protein, etc.) contained within fluid 22 can be moved from input fluid reservoir 18 to output fluid reservoir 20 using electrostatic forces via mechanisms known to those skilled in the art. Electrical contact can be achieved through input fluid reservoir 18 and output fluid reservoir 20. As the sample passes through the laterally exposed portion 25 of channel 16, the sample can interact with radiation from the first radiation source 34 entering channel 16 from waveguides 32A-C (collectively referred to as waveguide 32, also called waveguide structure). The first radiation 44 can enter channel 16 after being transmitted from the first radiation source 34, through the first coupler 36, through the first portion of waveguide 32, and through the first wall 16A on the first side 16X of channel 16. After passing through channel 16, the first radiation 42 and any fluorescence signals can exit through the second wall 16B of the second side 16Y of channel 16 and can then be transmitted to the first photodiode array 11 by the remainder of waveguide 32. Channel 16 also includes an upper wall 16C. As the walls 16A, 16B, and 16C of waveguide 32 and channel 16 are formed of the same material, as described in more detail below, the first radiation 44 passes through channel 16 with lower loss than in prior art optofluidic sensors. For the same reason, any fluorescence radiation generated by the sample in fluid 22 and entering waveguide 32 will experience lower loss as it travels to the first photodiode array 11 compared to prior art optofluidic sensors.

[0015] In the illustrated example, the first photodiode array 11 may include at least one exemplary doped first photodiode 28 (e.g., one or more PIN diodes) formed below the surface of a material layer on which a channel 16 or waveguide 32 may be formed. Of course, those skilled in the art will understand upon fully reading this application that the first photodiode array 11 may include any number of first photodiodes 28. In some cases, the first photodiode array 11 may be omitted entirely and the device may include only a second photodiode array 13. The first photodiodes 28 may have any physical size or configuration, and in the presence of more than one photodiode, the size and configuration of each first photodiode 28 need not be identical, but may be identical in some applications. The first photodiodes 28 may include different materials, such as doped semiconductor materials like germanium, silicon, silicon-germanium, germanium-tin, III-V group materials, etc. Techniques for forming such first photodiodes 28 are well known to those skilled in the art. In the specific example shown herein, the first photodiodes 28 may have a substantially rectangular configuration, wherein, when viewed from above, the long axis of the first photodiode 28 (in) Figure 1 (Extending from left to right) is basically parallel to the centerline 16L of channel 16 (see...) Figure 2 Orientation is achieved by means of the first photodiode 28. Of course, when viewed from above, the first photodiode 28 can have a substantially square configuration, wherein one axis of the first photodiode 28 is oriented substantially parallel to the centerline 16L. Those skilled in the art will understand upon a full reading of this application that, in this particular example of device 10, when illuminated by the first and / or second radiation sources 34, 38, the first photodiode 28 can be adapted to sense the orthogonal fluorescence of a sample in the fluid 22 flowing through channel 16. To reduce losses due to unwanted fading or thermal coupling, any photonic component should be isolated 2-3 μm from the silicon or germanium component (e.g., the substrate 12 comprising silicon or germanium). Figure 1 A first conductive structure 48 (e.g., a metal wire, a metal silicide) that can be conductively coupled to the first photodiode 28 is also shown. A conductive contact 80, simply illustrated, can be conductively coupled to the first conductive structure 48. Other conductive contacts 80 can be conductively coupled to portions of the active layer(s) of the semiconductor substrate 12, as described more fully below.

[0016] In the illustrated example, the second photodiode array 13 may include at least one exemplary doped second photodiode 30 formed below the surface of a material layer on which channels 16 and / or waveguides 32 may be formed. Of course, those skilled in the art will understand upon fully reading this application that the second photodiode array 13 may include any number of second photodiodes 30, and in some cases, the second photodiode array 13 may include only a single second photodiode 30. However, in some applications, the second photodiode array 13 may be omitted entirely. The second photodiode 30 may have any physical size or configuration, and when more than one second photodiode 30 is present, the size and configuration of each second photodiode 30 need not be the same, but may be the same in some applications. The second photodiode 30 may be made of a variety of different materials, such as doped semiconductor materials, such as germanium, silicon, silicon-germanium, germanium-tin, III-V group materials, etc. Techniques for forming such second photodiodes 30 are well known to those skilled in the art. In a particular example, the second photodiode 30 may have a substantially rectangular configuration, wherein, when viewed from above, the long axis of the second photodiode 30 (in...) Figure 1 and 2 (Extending from top to bottom) can be substantially perpendicular to the centerline 16L of the channel 16 (see...) Figure 2 Orientation is achieved by means of the first photodiode 30. Of course, when viewed from above, the second photodiode 30 can have a substantially square configuration, wherein one axis of the second photodiode 30 can be oriented substantially perpendicular to the centerline 16L. Those skilled in the art will understand upon fully reading this application that the second photodiode 30 can be adapted to sense fluorescence generated by laser excitation parallel to the flow of a sample in the fluid 22 flowing through the channel 16. In the example of the second photodiode array 13 shown in the figures, the second photodiode array 13 includes a second photodiode 30 located below and across the channel 16. In this particular example, the second photodiode 30 is located downstream of the waveguide array 15 (in terms of the flow direction of the sample in the fluid 22), but this is not necessary in all applications. Furthermore, in some applications, either the first photodiode array 11 or the second photodiode array 13 can be omitted entirely. For example, in one particular embodiment, the first photodiode array 11 can be omitted, and the second photodiode array 13 can be positioned vertically below the waveguide array 15. As described above, in order to reduce losses due to unwanted fading or thermal coupling, any photonic component should be isolated from silicon or germanium components (e.g., substrate 12 comprising silicon or germanium) by 2-3 μm. Furthermore, to reduce errors, embodiments may isolate the second photodiode array 13 from the first photodiode array 11 by at least 2-3 μm. Figure 1The diagram also shows a second conductive structure 49 (e.g., a metal wire, a metal silicide) that can be conductively coupled to the photodiode 30. The conductive photodiode electrical contact 80, which is simply shown, can be conductively coupled to the conductive structure 49.

[0017] In the illustrated example, waveguide array 15 may include three exemplary waveguide structures 32A-C (generally referred to by reference numeral 32). Of course, those skilled in the art will understand upon fully reading this application that device 10 may include any number of waveguide structures 32, and in some cases, device 10 may include only a single waveguide structure 32. Each waveguide structure 32 is adapted to transmit radiation generated by the first radiation source 34 toward channel 16. Each waveguide structure 32 may be located between the first radiation source 34 and a first side 16X of channel 16. Waveguide structures 32 may be configured to support guided modes of a specific wavelength. Waveguide dimensions may be related to the wavelength of laser excitation and the refractive index of the waveguide core. Waveguide structures 32 may have any physical dimensions or configuration, and the dimensions and configurations of waveguide structures 32 need not be identical, but may be the same in some applications. Waveguide structures 32 may be made of a variety of different materials, such as semiconductor materials like silicon, silicon nitride, etc. Techniques for forming such waveguide structures 32 are well known to those skilled in the art. In the specific example shown in this article, waveguide structure 32 may have a substantially rectangular configuration, wherein, when viewed from above, the major axis of each waveguide structure 32 (in) Figure 1 (Extending from top to bottom) is essentially perpendicular to the centerline 16L of channel 16 (see...) Figure 2 Orientation is achieved by means of the waveguide structure 32. Of course, when viewed from above, any waveguide structure 32 can have a substantially square configuration, wherein one axis of such a waveguide structure 32 is substantially perpendicular to the centerline 16L for orientation. Those skilled in the art will understand upon a full reading of this application that the waveguide structure 32 is adapted to guide and / or direct the first radiation 44 generated by the first radiation source 34 toward the sample in the channel 16 and the fluid 22 therein.

[0018] The first and second radiation sources 34, 38 can take various forms. In one exemplary example, the first and second radiation sources 34, 38 may include optical fibers carrying radiation from one or more radiation generating devices (e.g., one or more lasers). In embodiments where one or both of the first and second radiation sources 34, 38 include optical fibers, such optical fibers can be coupled to device 10 using any of a variety of simply illustrated attachment mechanisms 36, 40 (e.g., trenches where optical fibers can be positioned and joined). The first and second radiation sources 34, 38 can be adapted to generate radiation of any desired wavelength. In one exemplary embodiment, the first and second radiation sources 34, 38 can be adapted to generate radiation with wavelengths falling in the range of 0.4–3.0 μm. In one exemplary embodiment, the first radiation source 34 can be adapted to generate first radiation 44 in a direction substantially perpendicular to the centerline 16L of the channel 16 (e.g., substantially perpendicular to the flow direction of the fluid 22), thereby causing any irradiated sample to fluoresce. In one exemplary embodiment, the second radiation source 38 may be adapted to generate second radiation 42 in a direction substantially parallel to the centerline 16L of the channel 16 (e.g., substantially parallel to the flow direction of the fluid 22), thereby causing the irradiated sample to fluoresce. In the particular example shown herein, the first radiation source 34 may be located on a first side 16X of the channel 16, while the photodiode 28 may be adjacent to a second opposite side 16Y of the channel 16.

[0019] The energy required to move fluid 22, and any sample therein, from input fluid reservoir 18 to output fluid reservoir 20 can be provided by various known systems and techniques, such as known pumping systems, known systems using capillary forces as the driving force for fluid 22, known systems using known electrophoretic forces, etc. The physical dimensions of input fluid reservoir 18 and output fluid reservoir 20 may vary depending on the specific application. Fluid 22 can be any suitable type of liquid, such as buffer, pH buffer, Tris buffer, Tris EDTA (ethylenediaminetetraacetic acid) buffer, etc. As described above, in one exemplary embodiment, fluid 22 may contain a sample, which may include biological materials such as DNA, viruses, proteins, etc. In other applications, fluid 22 may be substantially free of any particles or materials.

[0020] In the example of device 10 shown, at least one waveguide structure 32 may be positioned between the first radiation source 34 and the first photodiode 28. The waveguide structure 32 may extend from the first radiation source 34 to a first side 16X of the channel 16, upward along the first wall 16A from the first side 16X, and along the upper surface 16T of the channel 16. Figure 23The second wall 16B extends downward from the second side 16Y along the second wall 16B of the channel 16 and extends from the second side 16Y of the channel 16 to the first photodiode 28, and then extends above the first photodiode 28.

[0021] Figure 2 yes Figure 1 A copy, in which some reference labels and fluid flow arrows are omitted. Figure 2 The purpose is to show the locations where the various cross-sectional views shown in the accompanying drawings are presented. View AA is taken upstream or toward the input fluid reservoir 18, through the first photodiode 28, channel 16, and waveguide 32C. View AA is in Figure 3 , 4 Views 6, 8, 10, 12, 15, 18, and 21 are shown. View BB is a view taken downstream or towards the output fluid reservoir 20, through the second photodiode 30 and channel 16. View BB is shown in... Figure 5 , 7 Views 9, 11, 13, 16, 19, and 22 are shown. View CC is a cut-off view through waveguide structure 32, looking toward channel 16 and the first photodiode 28. View CC is shown in... Figure 23 As shown in the attached cross-sectional diagram, some of the materials are in... Figure 1 or Figure 2 The figures are not shown to avoid making the accompanying drawings too complex.

[0022] refer to Figure 3 In the illustrated example, device 10 can be formed over semiconductor substrate 12. Advantageously, embodiments of device 10 can be formed using back-end process (BEOL) technology, such that substrate 12 can include or be one or more devices formed using front-end process (FEOL), intermediate process (MOL), and / or BEOL technology, although substrate 12 can also be a bulk semiconductor wafer or can take other forms. For example, as Figure 3As shown, substrate 12 can be in the form of semiconductor-on-insulator (SOI), comprising a base semiconductor layer 12A, a buried insulating layer 12B on the base semiconductor layer 12A, and an active semiconductor layer 12C above the buried insulating layer 12B, wherein device 10 can be formed in and on the active semiconductor layer 12C. The thicknesses of the active semiconductor layer 12C and the buried insulating layer 12B may vary depending on the specific application, and it should be understood that the figures shown herein are not drawn to scale. Typically, the base semiconductor layer 12A will be thicker than the active semiconductor layer 12C. In one exemplary embodiment, the active semiconductor layer 12C may be substantially free of any appreciable amount of dopant material; that is, the active semiconductor layer 12C may be an intrinsic semiconductor material. In the case that substrate 12 is SOI, the active semiconductor layer 12C and the base semiconductor layer 12A need not be made of the same semiconductor material, but in some applications they may be the same. In some applications, the active semiconductor layer 12C and the base semiconductor layer 12A, or both, in the substrate 12 may be made of silicon, or they may be made of semiconductor materials other than silicon. Therefore, the terms "substrate" or "semiconductor substrate" should be understood to encompass all semiconductor materials and all forms of such materials. In the case where the substrate 12 is SOI, the buried insulating layer 12B may comprise any desired insulating material, such as silicon dioxide, silicon nitride, etc. As used herein and in the claims, the terms "substrate" or "semiconductor substrate" should also be understood to refer to the substrate as a whole. For example, in the case where the device 10 is formed on an SOI substrate, if it is stated that a flow path is defined at least partially in the substrate, it means that the flow path may be defined at least partially by the active semiconductor layer 12C alone, by the buried insulating layer 12B alone, by the base semiconductor layer 12A alone, or by any combination of the active semiconductor layer 12C, the buried insulating layer 12B, and the base semiconductor layer 12A. These terms will be used specifically where it is necessary to distinguish between the active layer 12C, the buried insulating layer 12B, or the substrate semiconductor layer 12A of the SOI substrate. For the remainder of the description and figures herein, the device 10 disclosed herein will be described and shown as being fabricated on a bulk semiconductor substrate, such as a conventional bulk silicon substrate.

[0023] like Figure 4-5 As shown, the intermediate form of device 10 may include an isolation structure 14, one or more active devices 50 for processing signals from photodiode arrays 11, 13, and regions 100, 110 of substrate 12, which may have first and second photodiodes 28, 30 formed thereon (see...). Figure 8 and 9The modified electrical properties of the photodiode arrays 11 and 13. One or more active devices 50 may be part of a processing system electrically connected to an optofluidic sensor (e.g., to a first photodiode 28) and may respond to changes in the electrical parameters of the optofluidic sensor, such as voltage or current. In embodiments, the substrate 12 may be patterned (using known masking and etching techniques) and an insulating material may be deposited to form various isolation structures 14 in the substrate 12. For example, after the substrate 12 is patterned and the etch mask is removed, an insulating material (e.g., silicon dioxide) may be deposited to overfill the openings formed in the substrate 12. A planarization process, such as a chemical mechanical planarization process, may then be performed to remove excess insulating material positioned outside the openings in the substrate 12 and above the upper surface of the substrate 12. The active devices 50 for processing signals from the photodiode arrays 11, 13 are represented by FETs, which may include source, drain, and gate regions 52, 54, 56, respectively. Source and drain regions 52, 54 may include respective silicide layers 58, 60, while gate region 56 may include gate oxide layer 62 and conductive gate material layer 64. Processes for forming such devices and suitable materials used therein are well known, and it should be understood that various devices can be formed as a complement to or alternative to FET 50. In addition to devices such as FET 50, first and second regions 100, 110 with modified electrical properties may also be prepared for the first and second photodiodes 28, 30 of the respective first and second photodiode arrays 11, 13. For example, if a p-type material is used to form substrate 12, regions 100, 110 may be n+ regions formed by well-known processes. Regions 100, 110 may also include silicide layers 102, 112, which in embodiments may be formed simultaneously with the silicide layers 58, 60 of FET 50 and / or other potentially formed devices.

[0024] Figure 6 and 7 It shows that it can be obtained from Figure 4 and 5 Another intermediate form of the device 10 obtained in the form shown is described. In an embodiment, an insulating material layer 14A, for example a dielectric material, can be deposited on... Figure 4 and 5 The entire illustrated region of device 10 is covered. For example, a thick BEOL dielectric material layer, such as silicon dioxide, can be deposited. Subsequently, a first patterned etch mask (not shown) can be formed over the first and second regions 100, 110 of device 10. An etching process can then be performed to remove exposed portions of the insulating material 14A, thereby defining areas where corresponding first and second photodiodes 28, 30 will be formed (see [link to image]). Figure 8 and 9 The first and second grooves 104 and 114. (e.g.) Figure 6 and 7 As shown, trenches 104, 114 may extend to the upper surface of each of the first and second regions 100, 110, although the first trench 104 may extend into the first region 100 and / or the second trench 114 may extend into the second region 112. In any case, the bottom of the first and second trenches 104, 114 may include the respective exposed surfaces of the respective first and second regions 100, 110. In embodiments, the first and second trenches 104, 114 may be patterned and formed such that, for example, the respective conductive portions of the silicide layers 102, 112 remain covered by the insulating material 14A. In some embodiments, the material of the insulating material 14A may be the same as the material used to form the insulating structure 14, although this is not necessarily the case.

[0025] Figure 8 and 9 It shows that it can be done by... Figure 6 and 7 The device shown is yet another intermediate form of device 10 obtained by performing several additional process operations. For example, multiple epitaxial semiconductor material regions in various regions of device 10 can be formed by performing known epitaxial semiconductor growth processes. The epitaxial semiconductor material regions can be formed under undoped conditions, or at least some of them can be doped in situ. The epitaxial semiconductor regions are indicated by different shades for ease of interpretation, and such shades should not be interpreted as the epitaxial semiconductor material regions being made of different materials, or as them being formed at different times in different processing steps, although this may be the case in some applications. In one exemplary process flow, all epitaxial semiconductor material regions can be formed by performing a single epitaxial growth process. In other process flows, a patterned hard mask layer (not shown) can be formed on device 10 to control the formation of a specific epitaxial semiconductor material and then the region of that material can be removed. The patterned hard mask layer can then be removed, and this process can be repeated as needed to form additional epitaxial semiconductor material in different regions of device 10.

[0026] like Figure 8 and 9As shown, a first epitaxial semiconductor material host layer 106 for the first photodiode 28 can be formed in the first trench 104, and a second epitaxial semiconductor material host layer 116 for the second photodiode 30 can be formed in the second trench 114. In embodiments, the first and second epitaxial semiconductor material host layers 106, 116 can be interpreted as forming the semiconductor host of the respective first and second photodiodes 28, 30, and may be referred to as such. The bottom of the semiconductor host may be electrically connected to and / or bonded to a portion of a respective region 100, 110. If the respective regions 100, 110 of the epitaxial materials 106, 116 are single-crystal materials, then either of the epitaxial materials 106, 116 may be a single-crystal material, such that the epitaxial material can be grown on the single-crystal material in the respective regions 100, 110. In one exemplary embodiment, the epitaxial semiconductor material 106 for the first photodiode 28 may be formed such that the upper surface 106S of the epitaxial material 106 is substantially coplanar with the upper surface 116S of the epitaxial material 116 and the upper surface 14AS of the insulating material 14A. Thereafter, a first conductive upper layer 108 may be formed on the epitaxial semiconductor material 106 for the first photodiode 28, and a second conductive upper layer 118 may be formed on the epitaxial semiconductor material 116 for the second photodiode 30. The conductive upper layers 108 and 118 may be formed of any conductive material, and they may be formed by performing known manufacturing techniques. In an embodiment, one or both of the conductive upper layers 108 and 118 may comprise polysilicon, such as p+ polysilicon.

[0027] The epitaxial semiconductor materials of the first and second body layers 106 and 116 can be formed from a variety of different materials, such as germanium (Ge), silicon-germanium (SiGe), silicon (Si), silicon carbide (SiC), etc. The semiconductor materials of the first and second body layers 106 and 116 used for the first and second photodiodes 28 and 30 do not need to be made of the same epitaxial semiconductor material, but this may be the case in some applications. Although depicted as having the same vertical thickness, the epitaxial semiconductor materials of the first and second body layers 106 and 116 do not need to have the same vertical thickness, but this may be the case in some applications. In one particular example, one or both of the first and second body layers 106 and 116 used for the first and second photodiodes 28 and 30 may include silicon-germanium, while in another example, one or both of the first and second body layers 106 and 116 may include germanium. In this embodiment, the material layers used to form the first and second regions 100, 110, the first and second body layers 106, 116, and the first and second conductive upper layers 108, 118 can be doped to form a pin diode, such that the first and second regions 100, 110 are n-type doped, the first and second body layers 106, 116 are undoped (intrinsically doped), and the first and second conductive upper layers 108, 118 are p-type doped. Other doping profiles may also be used depending on the performance requirements of the photodiode. The first and second regions 102, 112 may have enhanced doping to form low resistivity contacts to the metal / silicide. The first and second conductive upper layers 108, 118 may have silicide region "rings" along their edges for forming contact paths 82 to contact 80. Figure 10 , 11 The low-resistance contacts. Of course, it should be understood that the first and second regions 100, 110 can be formed by monolayer and / or material deposition using processes well known in the art, the body layers 106, 116 can be formed by monolayer and / or material deposition, and the first and second conductive upper layers 108, 118 can be formed by monolayer and / or material deposition.

[0028] Steering Figure 10 and 11Multiple patterning, material removal, and / or material deposition steps can be performed to form contact structure 80 to provide conductive pathways to silicide regions 102, 112 and conductive layers 108, 118. For example, additional insulating material 14B can be added and patterned, insulating material 14B can be removed to form trenches to expose the surface of corresponding parts or regions, and conductive material can be deposited to form contact paths 82, and additional such processes can be performed to form contact pads 84. The same or similar steps can be used to form contacts 66 for device 50, which may include contacts 68 and contact pads 70. It should be understood that the material of insulating material 14B can be the same as that of insulating material 14A and / or insulating material 14, but is not required to be. In embodiments, region 100 and silicide layer 102 may be a first conductive structure 48 ( Figure 1 As part of the second conductive structure 49, region 110 and silicide layer 112 may be a second conductive structure 49. Figure 1 Part of ).

[0029] like Figure 12 and 13 As shown, various patterning, deposition, growth, and / or removal process operations can be performed on device 10 to begin constructing channel 16 (see [reference]). Figure 1 and 2 A sacrificial trench core layer 160 and an initial channel wall layer 162 are formed. For example, the sacrificial trench core layer 160 can be formed by depositing additional insulating material, forming trenches for the core layer 160, depositing or growing material in the trenches to form the core layer 160, and then removing the additional insulating material. Alternatively, the material for the core layer 160 can be blanket-deposited, patterned, and unwanted material removed, leaving the sacrificial trench core layer 160. The initial channel wall layer 162 can be conformally deposited over the sacrificial trench core layer 160, for example by blanket-depositing material and removing unwanted excess material, for example by etching. In embodiments, the sacrificial trench core layer 160 may include a semiconductor material, such as polysilicon or germanium, or a combination of polysilicon and germanium, but other embodiments may use a polymer material for the core layer 160. The initial channel wall layer 162 may include any suitable selectively etched material, such as silicon nitride. Then, as... Figure 14-16 As shown, the sacrificial channel core layer 160 can be removed, for example by forming a hole in the initial channel wall layer 162 and etching out the core layer 160, leaving at least a portion of the initial channel wall layer 160 and the cavity therein forming the channel 16.

[0030] Turn now Figure 17-19Then, deposition of an additional layer 164, which is a material used to form the initial channel wall layer 162, can be performed. This additional layer can fill any holes in the initial channel wall layer 162, thicken the walls 16A-C of the channel 16, and provide material that can be used to form the waveguide structure 32. Once the additional layer 164 has been deposited, patterning and removal processes can be performed to form the waveguide structures 32, 32A-C, as... Figure 20-23 As shown. After forming waveguide structures 32, 32A-C, further process operations can be performed to manufacture the first and second attachment mechanisms 36, 40 (as shown). Figure 1 ).

[0031] Regarding the entire description, it should be understood that in the case of describing one or more insulating material layers, each layer may include multiple material layers, and these material layers may be made of different materials. For example, insulating material layer 14 may include one or more silicon dioxide and / or low-k material layers, wherein a silicon nitride layer (which serves as an etch stop layer) is located between the silicon dioxide and / or low-k material layers. The structures, compositions, and techniques used to form such insulating material layer 14 are well known to those skilled in the art. Exceptions, as stated above, regarding... Figure 10-11 For example, various simple conductive contacts 66, 80 are formed to contact various structures on the device. For example, Figure 10 A conductive contact 80 is shown, including a contact pad 84, which is electrically coupled via a conductive path 82 to a silicide region 102 adjacent to the first photodiode 28 and to a conductive cap 108 located on top of the first photodiode 28. Similarly, Figure 11 A conductive contact 80 including a contact pad 84 is shown, which is conductively coupled to a second photodiode 30 via a conductive path 82. Figure 1 The adjacent silicide region 112 and coupled to the second photodiode 30 ( Figure 1 The conductive layer 118 is on top. Furthermore, Figure 10 A conductive contact 66 is shown, including a contact pad 70, which is electrically coupled to source and drain silicide layers 58 and 60 and coupled to a conductive gate material layer 64 via a conductive path 68. The conductive contacts 80, which are simply shown, can have various forms and configurations, can be made of various different conductive materials, and can be manufactured by performing known fabrication techniques.

[0032] Various operational aspects of the exemplary device 10 will now be described. For example, a first radiation source 34 may be adapted to irradiate a sample in the fluid 22 by generating first radiation 44 to result in so-called orthogonal fluorescence of the irradiated sample in the fluid 22, wherein the first irradiation 44 is guided in a direction substantially perpendicular to the flow direction of the sample in the fluid within the channel 16, more specifically, in the region traversed by the waveguide structure 32. Furthermore, a second radiation source 38 may be adapted to irradiate a sample in the fluid 22 by generating second radiation 42 to result in so-called orthogonal fluorescence due to laser excitation parallel to the flow of the irradiated sample in the fluid 22, wherein the second irradiation 42 may be guided in a direction substantially parallel to the flow direction of the fluid 22 in the channel 16. Furthermore, a first photodiode 28 may be adapted to sense the orthogonal fluorescence of the sample in the fluid 22 flowing through the channel 16, while a second photodiode 30 may be adapted to sense the parallel fluorescence of the sample in the fluid 22 flowing through the channel 16. By providing fluorescence excited in orthogonal directions in a two-dimensional plane, the recognition of target samples can be increased and its correlation with the multidimensional shape of fluorescent samples (such as DNA, viruses, proteins, etc.).

[0033] Those skilled in the art will understand upon fully reading this application that the device 10 disclosed herein includes several configurations. Without a specific order of importance, device 10 includes an optofluidic sensor combined with or integrated with at least one photodetector (28 or 30), all of which may be formed on or above a single semiconductor substrate 12. In one particular embodiment, a first diode 28 and / or a second photodiode 30 may be formed below the surface on which the channel 16 is formed, which may allow for more efficient radiative transport, for example via evanescent coupling or adiabatic coupling. In an embodiment, the distance between the top of the first photodiode 28 and the bottom of the waveguide structure 32 is no more than about 2 μm, preferably less than about 0.5 μm, to ensure that evanescent / adiabatic coupling can occur when the first photodiode 28 includes germanium. Similarly, in an embodiment, the distance between the top of the second photodiode 30 and the bottom of the channel 16 is no more than about 2 μm, preferably less than about 0.5 μm, to ensure that evanescent / adiabatic coupling can occur when the second photodiode 30 includes germanium. Additionally, in this embodiment, the waveguide structure 32 used to transmit the first radiation 42 may be made of the same material as the wall of the channel 16. Using this same material can reduce losses as the first radiation propagates from the first radiation source 34 to the first photodiode 28.

[0034] The specific embodiments disclosed above are merely exemplary, as this disclosure can be modified and practiced in different but equivalent ways that will be apparent to those skilled in the art who benefit from the teachings herein. For example, the process steps described above can be performed in different orders. Furthermore, the details of the structures or designs shown herein are not limited in any way except as set forth in the following claims. Therefore, it is apparent that the specific embodiments disclosed above can be altered or modified, and all such changes are considered to be within the scope and spirit of this disclosure. It should be noted that the use of terms such as “first,” “second,” “third,” or “fourth” in this specification and the appended claims to describe various processes or structures is merely for brief reference to these steps / structures and does not necessarily imply that such steps / structures are performed / formed in such an ordered order. Of course, depending on the precise language of the claims, an ordered order of these processes may or may not be required. Therefore, the protection sought herein is set forth in the following claims.

Claims

1. An optofluidic device, comprising: Substrate; A channel formed on and defined by at least a portion of the upper surface of a first material layer formed on the substrate, the walls of the channel being formed of a second material comprising a dielectric material, the channel being adapted to receive fluid therein; Input fluid reservoir; An output fluid reservoir, wherein the channel is in fluid communication with both the input fluid reservoir and the output fluid reservoir; A first radiation source operatively coupled to the substrate, wherein the first radiation source is adapted to generate radiation in a first direction toward the channel, wherein the first direction is substantially perpendicular to the long axis of the channel; At least one first photodiode located below the channel, wherein each of the at least one first photodiode includes a semiconductor body having an upper surface located in the first material layer and a modified substrate region located below each of the at least one first photodiode semiconductor bodies; A second radiation source, wherein the second radiation source is adapted to generate radiation in a direction substantially parallel to the long axis of the channel; and At least one second photodiode is positioned below the channel and optically coupled to the channel, the at least one second photodiode being spaced apart from the at least one first photodiode in a direction parallel to the long axis of the channel.

2. The optofluidic device according to claim 1, wherein, The top of the at least one first photodiode is positioned less than 2 μm below the bottom of the at least one waveguide structure.

3. The optofluidic device according to claim 2, wherein, The top of the at least one first photodiode is positioned no more than 0.5 μm below the bottom of the at least one waveguide structure.

4. The optofluidic device according to claim 1, wherein, The at least one first photodiode is also adjacent to the channel, and the optofluidic device further includes at least one waveguide structure formed of the second material, the at least one waveguide structure being arranged to transmit radiation from the first radiation source to the channel and from the channel to the at least one first photodiode.

5. The optofluidic device according to claim 4, wherein, The at least one first photodiode comprises a semiconductor material and the second material comprises a dielectric material.

6. The optofluidic device according to claim 5, wherein, The at least one first photodiode comprises germanium, and the second material comprises silicon nitride.

7. The optofluidic device according to claim 4, wherein, The first radiation source is positioned adjacent to a first side of the channel, the at least one first photodiode is positioned adjacent to a second side of the channel opposite to the first side of the channel, and the at least one waveguide structure extends from the first radiation source to the first side of the channel and from the second side of the channel to the at least one first photodiode.

8. The optofluidic device according to claim 7, wherein, The at least one waveguide structure also extends from the first side of the channel to the second side of the channel above the top of the channel.

9. The optofluidic device according to claim 4, wherein, The dimensions and shape of the channel are designed to function as a second waveguide structure in addition to transferring fluid from the input fluid reservoir to the output fluid reservoir.

10. The optofluidic device according to claim 9, wherein, The channel has opposite first and second sides, the first radiation source is adjacent to the first side of the channel, and the at least one first photodiode is also adjacent to the second side of the channel.

11. The optofluidic device according to claim 1, wherein, The substrate is a bulk semiconductor substrate, and the optical fluid control device further comprises: Shallow trench isolation is located in the substrate beneath the first material layer and around each region of the modified substrate; A first contact structure electrically coupled to each semiconductor body and a corresponding first contact pad in the at least one first photodiode; and The second contact structure is electrically coupled to each modified substrate region and the corresponding second contact pad in the at least one first photodiode.

12. The optofluidic device according to claim 1, further comprising: At least one component formed on the substrate is electrically connected to the at least one first photodiode and is configured to send an alarm in response to a change in the electrical parameters of the at least one first photodiode.

13. The optofluidic device according to claim 12, further comprising: A shallow trench isolation is located in the substrate below the first material layer, wherein the at least one component includes a field-effect transistor (FET) formed in the substrate and the first material layer, and the shallow trench isolation is also formed around the FET.

14. An optofluidic device, comprising: Substrate; A channel adapted to receive fluid therein, the channel being defined at least partially by at least the upper surface of a first material layer formed on the substrate, and the channel having a long axis and opposing first and second sides, the walls of the channel being formed of a second material comprising a dielectric material; Input fluid reservoir; An output fluid reservoir, wherein the channel is in fluid communication with the input fluid reservoir and the output fluid reservoir and is arranged to transfer fluid from the input fluid reservoir to the output fluid reservoir; A first radiation source, operatively coupled to the substrate, wherein the first radiation source is adapted to generate radiation in a direction substantially perpendicular to the long axis of the channel; At least one first waveguide structure formed of the second material and extending from the first radiation source to the first side of the channel, wherein the at least one first waveguide structure is adapted to transmit radiation from the first radiation source to the first side of the channel; At least one first photodiode is positioned adjacent to and vertically below the second side of the channel, and the at least one first waveguide structure further extends above the top of the channel and from the second side of the channel to above the at least one first photodiode. The lateral exposed portion of the channel is at least partially defined by the extent of the at least one first waveguide structure along the long axis of the channel, and wherein, during operation, radiation from the first radiation source passes through the first side of the channel, through the channel, and exits from the second side of the channel. At least one second photodiode is positioned vertically below the channel and at least 2 μm away from the at least one first photodiode along the long axis of the channel; as well as A second radiation source operatively coupled to the substrate, wherein the second radiation source is adapted to generate radiation in a direction substantially parallel to the long axis of the channel, the dimensions of the channel and the material to which it is made are designed to act as a second waveguide structure.

15. The optofluidic device according to claim 14, wherein: The at least one second photodiode is positioned no more than 2 μm below the channel.

16. The optofluidic device according to claim 15, wherein, The at least one first waveguide structure enables radiation to be transmitted from the first radiation source to the first side of the channel, through the channel in the lateral exposed portion, and from the second side of the channel to the at least one first photodiode.

17. The optofluidic device according to claim 14, further comprising: At least one component formed on the substrate is electrically connected to the at least one first photodiode and is configured to send an alarm in response to a change in the electrical parameters of the at least one first photodiode.

18. An optofluidic device, comprising: An optofluidic sensor system includes a substrate on which a first material layer is formed, an input fluid reservoir, an output fluid reservoir, and a channel formed on an upper surface of the first material layer and in fluid communication with the input fluid reservoir and the output fluid reservoir. The walls of the channel are formed of a second material comprising a dielectric material. The optofluidic sensor system further includes at least one radiation source operatively coupled to the substrate such that the at least one radiation source is in photonic communication with the channel. At least one photodiode in the first material layer is positioned below the channel such that the at least one photodiode receives radiation from the at least one radiation source and passes through the channel. Each of the at least one photodiode includes a semiconductor body having an upper surface in the first material layer and a modified substrate region located below each semiconductor body in the at least one photodiode. as well as A processing system, formed on the substrate and electrically connected to the optofluidic sensor system, includes at least one component electrically connected to the at least one photodiode and responding to changes in the electrical parameters of the at least one photodiode. The at least one radiation source includes: a first radiation source adapted to generate radiation in a first direction toward the channel, wherein the first direction is substantially perpendicular to the long axis of the channel; and a second radiation source adapted to generate radiation in a direction substantially parallel to the long axis of the channel. The at least one photodiode includes at least one first photodiode and at least one second photodiode optically coupled to the channel, wherein the at least one second photodiode is spaced apart from the at least one first photodiode in a direction parallel to the long axis of the channel.

19. The optofluidic device according to claim 18, wherein, The at least one photodiode is positioned no more than 2 μm below the channel, and the optofluidic device further includes at least one waveguide structure photonically connected to a corresponding radiation source and the at least one photodiode in the at least one radiation source.

20. The optofluidic device according to claim 18, wherein, The at least one waveguide structure includes at least one of the following: The second radiation source emits radiation along the long axis of the channel and above the at least one second photodiode directly below the channel; as well as At least one waveguide, formed of a layer of the second material, extends from the first radiation source to a first side of the channel, upward to a first sidewall of the channel, along the upper wall of the channel, downward to a second sidewall of the channel opposite to the first sidewall, and above the at least one first photodiode located below and adjacent to the second side of the channel.

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