Microbolometer system and method

Abstract

Microbolometer systems and methods are provided herein. For example, an infrared imaging device includes a microbolometer array. The microbolometer array includes a plurality of microbolometers. Each microbolometer includes a microbolometer bridge, the microbolometer bridge including a first portion and a second portion. The first portion includes a resistive layer configured to capture infrared radiation. The second portion has a plurality of perforations defined therein.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 816,889, filed on March 11, 2019, entitled “VERTICAL MICROBOLE CONTACT SYSTEM AND METHOD,” the entire contents of which are hereby incorporated by reference.

[0003] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 907,548, filed on September 27, 2019, entitled “Microbolometer Systems and Methods,” the entire contents of which are hereby incorporated by reference.

[0004] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 907,555, filed on September 28, 2019, entitled “Microbolometer Systems and Methods,” the entire contents of which are hereby incorporated by reference.

[0005] This application is related to U.S. Patent Application No. 16 / 226,580, filed on December 19, 2018, entitled “Vertical Microbolometer Contact System and Method,” which in turn is a part of U.S. Patent Application No. 15 / 396,100, filed on December 30, 2016, entitled “Vertical Microbolometer Contact System and Method,” which in turn is a continuation of International Patent Application No. PCT / US2015 / 039138, filed on July 2, 2015, entitled “Vertical Microbolometer Contact System and Method,” which in turn claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 020,747, filed on July 3, 2014, entitled “Vertical Microbolometer Contact System and Method,” all of which are hereby incorporated by reference in their entirety. Technical Field

[0006] One or more embodiments of the present invention relate generally to infrared cameras, and more particularly to microbolometer contact systems and methods, such as vertical leg contacts for microbolometer focal plane arrays. Background Art

[0007] A microbolometer is an embodiment of an infrared detector type that can be used in infrared imaging devices (e.g., infrared cameras). For example, microbolometers are typically fabricated on a monolithic silicon substrate to form an infrared (image) detector array, each microbolometer of the infrared detector array acting as a pixel to produce a two-dimensional image. The resistance change of each microbolometer is converted into a time-multiplexed electrical signal by means of a circuit called a readout integrated circuit (ROIC). The combination of an ROIC and an infrared detector array (e.g., a microbolometer array) is typically referred to as a focal plane array (FPA) or an infrared FPA (IRFPA). Additional details about FPAs and microbolometers can be found in U.S. Patent Nos. 5,756,999, 6,028,309, 6,812,465, and 7,034,301, the entire contents of which are incorporated herein by reference.

[0008] Each microbolometer in the array is generally connected to one or more contacts extending vertically downward from the array to the ROIC. The contacts can be used to provide a reference voltage for the microbolometer and / or provide a signal path from the microbolometer to the ROIC. The microbolometer generally includes a photosensitive portion formed of a resistive material suspended from a bridge, the resistive material being connected to the contacts by legs extending from the bridge to the contacts. The legs are attached to the resistive material through the contacts of the resistive material.

[0009] One of the challenges in designing efficient microbolometers is to increase the ratio of the photosensing area or active pixel area to the total area of ​​the array, sometimes referred to as the fill factor of the array. The legs that support each microbolometer can occupy a large portion of the array area, thus limiting the fill factor of the array. Therefore, it is desirable to reduce the area occupied by the legs. However, to maintain the performance of the device, the width and length of each leg should be proportional to the area of ​​each pixel. Therefore, it is difficult to reduce the leg area and improve the fill factor. Therefore, there is a need for improved techniques to implement leg supports, such as microbolometer-based focal plane arrays. Summary of the invention

[0010] According to one or more embodiments, systems and methods are disclosed that relate to microbolometer legs for infrared detectors. For example, according to one embodiment of the present invention, vertical legs are disclosed, (e.g., for infrared detectors in a focal plane array), which may be more area-efficient than conventional legs that extend substantially horizontally in a plane with the infrared detector. For one or more embodiments, the leg systems and methods disclosed herein may provide advantages over conventional leg approaches, particularly as semiconductor processing technology transitions to smaller sizes.

[0011] According to one embodiment, an infrared imaging device includes a substrate including a plurality of contacts and a surface. The surface defines a plane. The infrared imaging device also includes a microbolometer array coupled to the substrate, wherein the microbolometer array includes a plurality of microbolometers. Each microbolometer includes a bridge and a leg structure coupled to the bridge and one of the plurality of contacts. The leg structure includes a metal layer having: a first dimension extending in a first direction, the first dimension being substantially perpendicular to the plane; a second dimension extending in a second direction, the second dimension being substantially parallel to the plane, wherein the first dimension is greater than the second dimension. The leg structure further includes a first layer formed on a first sidewall of the metal layer and a first sidewall of the metal layer. The leg structure also includes a second layer formed on a second sidewall of the metal layer and a second side of the metal layer. The first sidewall is opposite to the second sidewall. The first side is opposite to the second side.

[0012] According to one embodiment, an infrared imaging device includes a microbolometer array, the microbolometer array including a plurality of microbolometers. Each microbolometer includes a bridge. The bridge includes a first portion and a second portion, the first portion including a resistive layer configured to capture infrared radiation, the second portion having a plurality of perforations defined therein.

[0013] According to one embodiment, an infrared imaging device includes an array of microbolometers, each microbolometer having a bridge coupled to a contact via at least one vertical bolometer leg. The legs and bridge of the microbolometer array may be suspended above a readout integrated circuit of the microbolometer array. The vertical bolometer legs may be formed using spacer deposition and etching process operations that form at least a portion of the vertical bolometer legs on the sidewalls of the opening of the sacrificial layer and are then removed to release the bolometer legs.

[0014] According to various embodiments, the vertical bolometer legs may extend along a path that is arranged in a plane parallel to a plane defined by a bridge of the microbolometer and / or a plane defined by a substrate surface of the device (e.g., a readout integrated circuit substrate), and may have an extended dimension that extends in a direction perpendicular to the plane of the path, the substrate surface, and / or the plane of the bridge. In this way, the area of ​​the bolometer legs that would otherwise occupy a relatively large portion of the surface area of ​​the microbolometer array may be reduced without reducing the area of ​​the bolometer legs.

[0015] Depending on the implementation, the leg structure may or may not be encapsulated in an insulating layer, such as silicon dioxide or silicon nitride. The leg structure may be formed from multiple layers of insulating material to optimize performance. The leg conductive layer may be fully or partially encapsulated by an insulating layer or may not contain any insulating layer. The leg conductive layer may be a homogeneous film of a single material type or may be a multi-layer conductive layer formed, for example, from several deposits.

[0016] According to one embodiment, an infrared imaging device includes a substrate having a plurality of contacts and a surface. The surface defines a plane. The infrared imaging device also includes a microbolometer array coupled to the substrate, wherein the microbolometer array includes a plurality of microbolometers. Each microbolometer includes a bridge and a leg structure coupled to the bridge and one of the plurality of contacts. The leg structure includes a cross-section having a first portion, a second portion substantially parallel to the first portion, and a third portion connecting the first portion and the second portion. In some aspects, the bridge has a first portion and a second portion. The first portion includes a resistive layer configured to capture infrared radiation. The second portion includes a plurality of perforations defined therein.

[0017] According to one embodiment, a method for forming an infrared imaging device includes forming a bridge on a sacrificial layer. The method further includes forming an opening in the sacrificial layer. The method further includes arranging a contact metal layer on the sidewalls of the opening. The method also includes forming a leg structure connected to the bridge and the contact metal layer. The leg structure has a cross-section having a first section, a second section substantially parallel to the first section, and a third section connecting the first section and the second section. The method also includes removing the sacrificial layer to suspend the bridge and the leg structure above a substrate of the infrared imaging device. The contact metal layer is connected to the substrate.

[0018] According to one embodiment, an infrared imaging device includes a microbolometer array having a plurality of microbolometers. Each microbolometer includes a microbolometer bridge. The microbolometer bridge includes a first portion including a resistive layer configured to capture infrared radiation; and a second portion having a plurality of perforations defined therein. In some aspects, the infrared imaging device further includes a substrate including a plurality of contacts and a surface. The surface defines a plane. Each microbolometer further includes a leg structure coupled to the microbolometer bridge and one of the plurality of contacts. The leg structure includes a cross-section having a first section, a second section, and a third section, the second section being substantially parallel to the first section, and the third section connecting the first section and the second section.

[0019] According to one embodiment, a method of forming an infrared imaging device includes forming a bridge structure. The method further includes forming a leg structure. The method further includes forming a plurality of perforations in the bridge structure to obtain a microbolometer bridge.

[0020] According to one embodiment, a method of forming an infrared imaging device includes forming a bridge on a sacrificial layer, wherein the bridge includes a first portion having a resistive layer configured to capture infrared radiation and a second portion having a plurality of perforations formed therein. The method also includes forming an opening in the sacrificial layer. The method further includes arranging a contact metal layer on a sidewall of the opening. The method further includes forming a leg structure coupled to the bridge and the contact metal layer. The method also includes removing the sacrificial layer and suspending the bridge and the leg structure above a substrate of the infrared imaging device, wherein the contact metal layer is coupled to the substrate.

[0021] The scope of the present invention is defined by the claims, which are incorporated by reference into the Summary of the Invention. A more complete understanding of the embodiments of the present invention and the realization of additional advantages thereof will be obtained by those skilled in the art by considering the following detailed description of one or more embodiments. Reference will be made to the accompanying drawings, which will first be briefly described. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A block diagram illustrating an infrared camera is shown in accordance with one or more implementations.

[0023] Figure 2 A block diagram illustrating an example of an infrared camera is shown in accordance with one or more implementations.

[0024] Figure 3 A diagram showing a physical layout of a microbolometer of an array of microbolometers having vertical legs according to one embodiment.

[0025] Figure 4A and 4B A top view and a cross-sectional side view, respectively, of a conventional horizontal leg for a microbolometer are shown.

[0026] Figure 5A and 5B A top view and a cross-sectional side view, respectively, of a vertical leg (eg, a leg used to couple an infrared detector element to a contact) are shown in accordance with one embodiment.

[0027] Figures 6A to 6F A method for manufacturing a vertical leg (e.g., for Figure 3 Schematic diagram of the processing of the vertical support leg).

[0028] Figures 7A to 7FA method for manufacturing a vertical leg (e.g., for Figure 3 Another machining overview of the vertical legs.

[0029] Figures 8A to 8C A method for manufacturing a vertical leg (e.g., for Figure 3 Another processing overview of the vertical legs).

[0030] Fig. 9 A cross-sectional side view of a portion of a focal plane array having vertical legs formed below the surface of the array near vertical contacts between an infrared detector array and a readout integrated circuit is shown in accordance with one embodiment.

[0031] Fig.10 A cross-sectional side view of a portion of a focal plane array near a sensor of the array is shown according to one embodiment, with vertical legs formed below the surface of the array.

[0032] Fig.11 A cross-sectional side view of a portion of a focal plane array having vertical legs formed below the array surface near vertical contacts between an infrared detector array and a readout integrated circuit is shown in accordance with one embodiment.

[0033] Fig.12 A cross-sectional side view of a portion of a focal plane array near a sensor of the array is shown according to one embodiment, with vertical legs formed below the surface of the array.

[0034] Figures 13A to 13Q Vertical legs (e.g. Figure 5A and 5B Various arrangements of vertical legs).

[0035] Fig.14 A cross-sectional side view of a portion of a focal plane array having vertical legs formed at or above a surface of the array near a vertical contact between an infrared detector array and a readout integrated circuit is shown in accordance with one embodiment.

[0036] Fig.15 A cross-sectional side view of a portion of a focal plane array near a sensor of the array is shown according to one embodiment, with vertical legs formed above the surface of the array.

[0037] Fig.16 A top view of a curved portion of a vertical leg according to one embodiment is shown, for example, Figure 3 near the bend of the vertical leg.

[0038] Fig.17 According to one embodiment, Fig.16 A cross-sectional view of an example arrangement of vertical legs.

[0039] Fig.18 According to one embodiment, Fig.16 A cross-sectional view of another example arrangement of vertical legs.

[0040] Fig.19 A cross-sectional view of a portion of a focal plane array having a leg (eg, a leg for an infrared detector) formed at least partially beneath a bridge portion of the infrared detector is shown according to one embodiment.

[0041] Fig. 20 A method for manufacturing a vertical leg (e.g. Figure 3 vertical legs).

[0042] Fig.21 A method for manufacturing a vertical leg (such as Figure 3 Another flow chart of the vertical legs).

[0043] Fig. 22 Another flow chart for manufacturing a vertical leg according to one embodiment is shown, for example Figure 3 Vertical legs.

[0044] Figures 23A to 23F A method for fabricating vertical legs (e.g., for Figure 3 Schematic diagram of the processing of the vertical support leg).

[0045] Fig.24 A cross-sectional view of a portion of a focal plane array having a leg (eg, a leg for an infrared detector) formed at least partially beneath a bridge portion of the infrared detector is shown in accordance with one embodiment.

[0046] Fig.25 A flow chart for fabricating a focal plane array having legs (eg, legs for infrared detectors) formed at least partially beneath a bridge portion of the infrared detectors is shown according to one embodiment.

[0047] Fig.26 Shown is a top view of the bolometer.

[0048] Fig. 27 Shows Fig.26 Cross section of a bolometer leg.

[0049] Fig.28The rigidity provided by the vertical members is shown.

[0050] Fig.29 A top view of a bolometer with vertical legs is shown according to one embodiment.

[0051] Fig. 30A According to one embodiment, Fig.29 Cross section of a bolometer leg.

[0052] Fig. 30B According to one embodiment, Fig. 30A The height of the outrigger is smaller than the cross-section of the outrigger.

[0053] Fig.31 A cross section of a leg of a bolometer according to one embodiment is shown.

[0054] Fig.32 A top view of a bolometer with a bridge, vertical legs, and contacts is shown according to one embodiment, wherein the bolometer is fabricated using an oxide method.

[0055] Fig.33 According to one embodiment, Fig.32 Cross section of the leg.

[0056] Fig.34 A top view of a bolometer having a bridge, vertical legs, and contacts is shown according to one embodiment, wherein the bolometer is fabricated using a directed self-assembly method.

[0057] Fig.35 According to one embodiment, Fig.34 Cross section of the leg.

[0058] Figures 36A to 36N A cross-sectional side view is shown relating to an example process of forming a bolometer according to one embodiment.

[0059] Fig.37 According to one embodiment, Fig.36N The cross-sectional side view corresponds to the top view.

[0060] Figures 38A to 38D A cross-sectional side view is shown relating to an example process of forming contacts according to one embodiment.

[0061] Figures 39A to 39D A cross-sectional side view is shown relating to an example process of forming legs after forming contacts to a readout circuit wafer according to one embodiment.

[0062] Fig.39E Shows Fig.39D An enlarged view of a portion of a structure.

[0063] Fig.40 According to one embodiment, the corresponding Fig.39D A top view of a cross-sectional side view.

[0064] Figures 41A to 41T A cross-sectional side view is shown in connection with an example process of forming a bolometer according to one embodiment.

[0065] Fig.42 According to one embodiment, Figure 41T The cross-sectional side view corresponds to the top view.

[0066] Fig.43A and 43B A diagram related to a bolometer is shown according to one embodiment.

[0067] Figures 44A to 44E Various views are shown relating to another bolometer according to one embodiment.

[0068] Figures 45A to 45F A cross-sectional side view is shown relating to an example process of forming a bolometer according to one embodiment.

[0069] Figures 46A to 46F According to one embodiment, Figures 45A to 45F An overhead view of an example process.

[0070] Fig.47A and 47B Shows Fig.45C Magnified view of the identified portion.

[0071] Fig.48 is a flow chart of illustrative operations that may be performed to form a thermal bolometer according to one embodiment.

[0072] Fig.49 is a perspective view of a bolometer according to one embodiment.

[0073] Fig.50 According to one embodiment, Fig.49 Top view of the thermal radiation meter.

[0074] Figures 51A to 51C Other examples of bolometers according to one or more implementations are shown.

[0075] Fig.52 A cross-sectional side view of a portion of a bolometer is shown according to one embodiment.

[0076] Fig.53A cross-sectional side view of a portion of a bolometer having a through-hole defined therein is shown according to one embodiment.

[0077] Fig.54 is a flow chart of illustrative operations performed to form a bolometer having perforations defined in a bolometer bridge according to one embodiment.

[0078] Figures 55A to 55D A cross-sectional side view is shown relating to an example process of forming a bolometer according to one embodiment.

[0079] Fig.56 According to one embodiment, Fig.55D The cross-sectional side view corresponds to the top view.

[0080] Embodiments of the present invention and their advantages may be best understood by referring to the following detailed description.It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the Figures. DETAILED DESCRIPTION

[0081] Systems and methods are disclosed herein that, according to one or more embodiments, provide vertically oriented legs for infrared detectors. For example, according to one embodiment, vertical bolometer legs are disclosed, such as for use with microbolometers in a focal plane array. As an example, Figure 1 A block diagram is shown showing a system 100 (e.g., an infrared camera, which includes any type of infrared imaging system) for image capture and processing according to one or more embodiments. In one embodiment, system 100 includes an image capture component 102, a processing component 104, a control component 106, a storage component 108, and a display component 110. Optionally, system 100 may include a sensor component 112.

[0082] System 100 may represent, for example, an infrared imaging device (e.g., an infrared camera) to capture and process images (e.g., video images of scene 101). System 100 may represent any type of infrared camera that employs an infrared detector with contacts that may be implemented as disclosed herein. System 100 may include a portable device and may be incorporated into, for example, a vehicle (e.g., an automobile or other type of land vehicle, aircraft, or spacecraft) or a non-mobile device that requires storage and / or display of infrared images, or may include a distributed network system (e.g., processing component 104 is remote from and controls image capture component 102 via a network).

[0083] In various implementations, processing component 104 may include any type of processor or logic device (e.g., a programmable logic device (PLD) configured to perform processing functions). Processing component 104 may be adapted to interface and communicate with components 102, 106, 108, and 110 to perform method and processing steps and / or operations (e.g., controlling bias and other functions (e.g., values ​​of elements such as variable resistors and current sources, switch settings for bias and timing, and other parameters)) and other conventional system processing functions as understood by those skilled in the art.

[0084] In one embodiment, storage component 108 includes one or more storage devices suitable for storing data and information (including, for example, infrared data and information). Storage component 108 may include one or more storage devices of various types, including volatile and non-volatile storage devices, including computer-readable media (portable or fixed). Processing component 104 may be adapted to execute software stored in storage component 108 to perform the method and processing steps and / or operations described herein.

[0085] Image capture component 102, in one embodiment, includes one or more infrared sensors (e.g., any type of multi-pixel infrared detector, such as a focal plane array having one or more vertical legs as disclosed herein) for capturing infrared image data (e.g., still image data and / or video data) representing an image (e.g., scene 101). In one embodiment, the infrared sensor of image capture component 102 provides for representing (e.g., converting) the captured image data into digital data (e.g., via an analog-to-digital converter included as part of the infrared sensor or separate from the infrared sensor as part of system 100). In one or more embodiments, image capture component 102 may further represent or include a lens, shutter, and / or other related components for capturing infrared image data in conjunction with the vacuum packaging assembly. Image capture component 102 may further include a temperature sensor (or the temperature sensor may be distributed within system 100) to provide temperature information about the operating temperature of image capture component 102 to processing component 104.

[0086] In one aspect, the infrared image data (e.g., infrared video data) may include non-uniform data (e.g., real image data) of an image (e.g., scene 101). Processing component 104 may be adapted to process the infrared image data (e.g., provide processed image data), store the infrared image data in storage component 108, and / or retrieve stored infrared image data from storage component 108. For example, processing component 104 may be adapted to process infrared image data stored in storage component 108 to provide processed image data and information (e.g., captured and / or processed infrared image data).

[0087] The control unit 106 includes a user input and / or interface device in one embodiment, such as a rotatable knob (e.g., a potentiometer), a button, a slide bar, a keyboard, etc., which is suitable for generating a user input control signal. The processing unit 104 can be suitable for sensing a control input signal from a user through the control unit 106 and responding to any sensed control input signal received therefrom. The processing unit 104 can be suitable for interpreting such a control input signal as a parameter value, as generally understood by those skilled in the art. In one embodiment, the control unit 106 can include a control unit (e.g., a wired or wireless handheld control unit) having a button suitable for connecting to a user interface and receiving a user input control value. In one embodiment, the buttons of the control unit can be used to control various functions of the system 100, such as autofocus, menu activation and selection, field of view, brightness, contrast, noise filtering, high pass filtering, low pass filtering and / or various other functions understood by those skilled in the art.

[0088] Display component 110, in one embodiment, includes an image display device (e.g., a liquid crystal display (LCD) or various other types of generally known video displays or monitors). Processing component 104 may be adapted to display image data and information on display component 110. Processing component 104 may be adapted to retrieve image data and information from storage component 108 and display any retrieved image data and information on display component 110. Display component 110 may include display electronics that may be utilized by processing component 104 to display image data and information (e.g., infrared images). Display component 110 may be adapted to receive image data and information directly from image capture component 102 via processing component 104, or the image data and information may be transmitted from storage component 108 via processing component 104.

[0089] The optional sensing component 112, in one embodiment, includes one or more sensors of various types, depending on the application or implementation requirements, as will be appreciated by those skilled in the art. The sensors of the optional sensing component 112 provide data and / or information to at least the processing component 104. In one aspect, the processing component 104 can be adapted to communicate with the sensing component 112 (e.g., by receiving sensor information from the sensing component 112) and with the image capture component 102 (e.g., by receiving data and information from the image capture component 102 and providing and / or receiving commands, controls, and / or other information to one or more other components of the system 100).

[0090] In various embodiments, the sensing component 112 can provide information about environmental conditions, such as external temperature, lighting conditions (e.g., daytime, nighttime, dusk, and / or dawn), humidity, certain weather conditions (e.g., sun, rain, and / or snow), distance (e.g., laser rangefinder), and / or whether a tunnel or other type of enclosure has been entered or exited. The sensing component 112 can represent conventional sensors commonly known to those skilled in the art for monitoring various conditions (e.g., environmental conditions) that may affect the data provided by the image capture component 102 (e.g., the appearance of the image).

[0091] In some embodiments, the optional sensing component 112 (e.g., one or more of the sensors) may include devices that communicate information via wired and / or wireless communications to the processing component 104. For example, the optional sensing component 112 may be adapted to receive information from a satellite, via a local broadcast (e.g., radio frequency (RF)) transmission, via a mobile or cellular network, and / or via information beacons in infrastructure (e.g., transportation or highway information beacon infrastructure), or various other wired and / or wireless technologies.

[0092] In various embodiments, the components of system 100 may be combined and / or implemented or not implemented as desired or as required by the application or requirement, with system 100 representing various functional blocks of the relevant system. In one embodiment, processing component 104 may be combined with storage component 108, image capture component 102, display component 110, and / or optional sensing component 112. In another embodiment, processing component 104 may be combined with image capture component 102, with only certain functions of processing component 104 being performed by circuitry (e.g., a processor, microprocessor, logic device, microcontroller, etc.) within image capture component 102. In addition, various components of system 100 may be remote from each other (e.g., image capture component 102 may include a remote sensor, with processing component 104, etc. representing a computer, which may or may not be in communication with image capture component 102).

[0093] Figure 2 1 shows a block diagram illustrating a specific embodiment of an infrared camera 200 according to one or more embodiments. The infrared camera 200 may represent the system 100 ( Figure 1 ), which will be understood by those skilled in the art.

[0094] Infrared camera 200 (e.g., a microbolometer readout integrated circuit with bias correction circuitry and interface system electronics) includes a readout integrated circuit (ROIC) 202 that may include an array of microbolometer cells having one or more contacts coupled to a microbolometer bridge via vertical legs as disclosed herein, control circuitry, timing circuitry, bias circuitry, row and column addressing circuitry, column amplifiers, and associated electronics to provide output signals that are digitized by analog-to-digital (A / D) converter 204. A / D converter 204 may be part of ROIC 202 or separate therefrom.

[0095] The output signal from the A / D converter 204 is conditioned by a non-uniformity correction circuit (NUC) 206, which applies temperature-dependent compensation, as will be appreciated by those skilled in the art. After processing by the NUC 206, the output signal is stored in a frame memory 208. The data in the frame memory 208 is then available to the image display electronics 210 and the data processor 214, which may also have a data processor memory 212. The timing generator 216 provides system timing.

[0096] The data processor 214 generates offset correction data words which are loaded into the correction coefficient memory 218. The data register loading circuit 220 provides an interface to load the correction data into the ROIC 202. In this manner, variable circuits (e.g., variable resistors that control voltage levels, biases, frame timing, circuit component values, digital-to-analog converters, bias circuits, etc.) are controlled by the data processor 214 so that the output signal of the ROIC 202 is uniform over a wide temperature range.

[0097] It should be understood that the various functional blocks of the infrared camera 200 can be combined, and various functional blocks may not be required, depending on the specific application and specific requirements. For example, the data processor 214 can perform various functions of the NUC 206, and various memory blocks (such as the correction coefficient memory 218 and the frame memory 208) can be combined as needed.

[0098] Figure 3 A physical layout diagram of a microbolometer 300 according to one embodiment of the present invention is shown. The microbolometer 300 includes a bridge portion 302 having a light sensor 304 and bridge contacts 306 coupling the sensor 304 to a first end of a leg 308. The legs 308 couple the sensor 304 to one of the contacts 310, respectively.

[0099] Each contact 310 may couple one or more associated microbolometers 300 to associated readout circuitry of a readout integrated circuit (ROIC, not shown). For example, a first contact 310 may be used to provide a reference or bias voltage to a microbolometer, and a second contact 310 may be used for a signal path from the microbolometer to the ROIC, through which a signal corresponding to infrared light absorbed by the microbolometer may be read. Further description of ROICs and microbolometer circuits may be found in U.S. Patent No. 6,028,309, which is hereby incorporated by reference in its entirety for all purposes.

[0100] The sensor 304 may be arranged to convert incident light (e.g., infrared light) into a detectable electrical signal, the conversion being based on a change in the electrical properties of the sensor (e.g., a change in resistivity) caused by a change in the temperature of the sensor when the light is incident. According to one embodiment, the sensor 304 may include a resistive material, which may be made of a high temperature coefficient of resistivity (TCR) material (e.g., vanadium oxide (VO x ), titanium oxide (TiO x ) or amorphous silicon). The resistive material may be suspended above the ROIC on the bridge 302 and connected to its contacts 310 via legs 308.

[0101] According to various embodiments, each contact 310 may be connected to a portion of a leg 308 that bends downward toward the ROIC (e.g., the contact 310 may be formed on a substrate such as the ROIC, and the leg 308 may include a portion extending from a first height above the substrate, such as the height of the bridge, downward to a non-perpendicular angle to the substrate contact) and / or each contact 310 may include a portion extending downward from the leg 308 to the surface of the ROIC (e.g., at a height of the bridge). Figure 3 The legs 308 may be formed from one or more layers of a conductive material, such as titanium, nickel chromium, and / or other suitable conductive materials.

[0102] In order to provide legs 308 with a width and length sufficient to provide suitable performance for microbolometer 300 without reducing the fill factor of a microbolometer array including microbolometer 300, legs 308 can be vertically oriented legs, as shown, along Figure 3 in the XY plane and / or parallel to Figure 3 The path of the XY plane extends and has a path parallel to Figure 3 The leg 308 may include a curved portion 312. The curved portion 312 may have additional electrical connections and / or support structures, as described in further detail below.

[0103] Such as Figure 3The plane of the xy plane may be defined by a bridge of the microbolometers (e.g., a bridge may include a planar sensor layer such as a resistive layer defining a plane, or may define a plane passing through multiple bridges in the microbolometer array) or by a surface of a substrate (e.g., a ROIC substrate) to which the microbolometer array is coupled and disposed.

[0104] Figure 4A and 4B A top view and a cross-sectional view of a conventional microbolometer 400 with horizontally oriented legs 406 are shown, respectively. Figure 4A As shown in the top view of FIG. 4 , the bridge 402 of the microbolometer 400 is connected to the horizontal leg 406 through the bridge contact 404, and the leg has a Figure 4A The width WP extending in the xy plane is the extension dimension. Figure 4A The AA line is intercepted Figure 4B In the cross-sectional view of FIG. 4 , it can be more easily seen that the contacts 404, legs 406, and resistive material 403 of the microbolometer 400 are all along the same plane or parallel to the Figure 4B The plane extends parallel to the xy plane.

[0105] on the contrary, Figure 5A and 5B 1 and 2 show a top view and a cross-sectional view of a microbolometer 500 according to an embodiment of the present disclosure, the embodiment including vertical legs 308. As shown in the figure, the vertical legs 308 are Figure 5A and 5B The width W may be defined in the XY plane of the embodiment of the present invention. By allowing the legs 308 to extend in a vertical direction (e.g., in the direction of Figure 5A and 5B The width W may be relatively smaller than the width WP of a conventional microbolometer leg without sacrificing the overall volume of the leg so that the vertical leg 308 is perpendicular to a plane defined by the bridge 302 (e.g., by the resistive material 501 of the bridge 302, by the bridge contacts 306, and / or by an array of bolometer bridges formed at a common height above the ROIC) and / or a plane defined by a substrate surface above which the bridge is formed.

[0106] As shown, according to one embodiment, the vertical leg 308 may include a conductive (e.g., metal) portion 506 and, if desired, an insulating material 508 on one or more sides of the conductive portion. However, this is merely illustrative. According to various embodiments, the conductive portion 506 may be partially or completely surrounded by a dielectric material, or may be free of dielectric material. Figures 13A-13QVarious embodiments of the vertical legs 308 are described. However, first, a method for forming a vertical leg 308 according to various embodiments will be discussed. Figure 3 , 5A and the process of the vertical bolometer legs of the vertical legs 308 of 5B.

[0107] Figures 6A-6F Shown are cross-sectional side views of a portion of a microbolometer array at various stages during the production of a microbolometer leg.

[0108] Now turn to Fig. 6A , a portion 601 of a microbolometer array is shown having contacts 310 and a bridge 302. As shown, the bridge 302 includes a sensor layer (e.g., a temperature-sensitive resistive material layer such as VO x ) 606 and one or more additional layers 604 (such as an absorber layer). As shown, contact 310 can be formed by a vertical conductive portion such as a metal stud 608 and one or more layers (such as a metal contact layer 614 in contact with the metal stud 608). Contact 310 can include additional layers (such as a dielectric layer 616 disposed on the metal layer 614) and additional layers 612 (such as a passivation layer disposed under a portion of the metal layer 614). As shown, layer 612 can be formed on a portion of the top surface 603 of the sacrificial layer 600. In some cases, a basket contact or other contact can be used instead of the metal stud 608.

[0109] Sacrificial layer 600 may be formed of, for example, polyimide. Layers 612 and 616 may be formed of, for example, silicon dioxide or silicon nitride. Metal layer 614 may be formed of titanium, tungsten, copper, aluminum, and / or other known metals.

[0110] The metal stud 608 may be conductively coupled to a conductive contact, such as a contact 610 of a substrate, such as a readout integrated circuit (ROIC) substrate, such as a complementary metal oxide semiconductor (CMOS) ROIC. Fig. 6A In the embodiment of the present invention, the contact 610 is disposed on a cover glass layer 602 (e.g., a CMOS cover glass layer) of the ROIC. Before forming the vertical legs between the bridge 302 and the contact 310, the bridge 302 can be arranged on a sacrificial layer 600, which supports the bridge 302 and fills the gap between the bridge of the microbolometer array and the ROIC and extends continuously between the bridge of the microbolometer array and the contact.

[0111] According to one embodiment, the process for forming the vertical leg between the bridge 302 and the contact 310 may include depositing and patterning an additional sacrificial layer 620 on the sacrificial layer 600, such as Figure 6B. Patterning the additional sacrificial layer 620 may include forming an opening 622 in the additional sacrificial layer (e.g., at least partially between the bridge 302 and the contact 310) so that the remaining portion of the additional sacrificial layer 620 has a vertical sidewall 625. The opening 622 may extend into the sacrificial layer 600, or may extend only to the top surface 603 of the sacrificial layer 600 (as an embodiment).

[0112] After the deposition and patterning of the additional sacrificial layer 620, a dielectric layer 624 may be deposited and patterned so that portions of the dielectric layer 624 remain on the sidewalls 625 of the additional sacrificial layer 620 in the opening 622, such as Figure 6C Then, a metal layer may be deposited over the contacts 310, portions of the sacrificial layer 600, the dielectric layer 624 on the sidewalls 625, portions of the additional sacrificial layer 620, and the bridge 302, as shown in FIG. Fig.6D If desired, openings may be formed in the dielectric layers of contacts 310 and bridges 302 to expose portions of metal layer 614 and sensor layer 606 so that metal layer 626 may be deposited in contact with metal layer 614 and sensor layer 606. Metal layer 626 may be deposited in a blank deposition process.

[0113] like Fig. 6E As shown, an additional dielectric layer 628 may be deposited over the metal layer 626, and then the metal layer 626 and the additional dielectric layer 628 may be etched (e.g., in a masked spacer etch process) to remove portions of the metal layer 626 and the additional dielectric layer 628 from the sacrificial layer 600 and the additional sacrificial layer 620. In this manner, a dielectric-metal-dielectric stack may be formed vertically on the sidewalls 625 of the opening 622. Portions of the dielectric-metal-dielectric stack that are continuously coupled to the portions on the sidewalls 625 may also remain on the contact 310 and the bridge 302, thereby forming the bridge contact 306 and the leg metal in contact with the metal layer 614 of the contact 310.

[0114] Dielectric layers 624 and 628 may be formed of, for example, silicon dioxide or silicon nitride. Metal layer 626 may be a single metal layer forming a homogeneous film of a single material, or may include multiple materials (e.g., multiple layers of the same or different materials formed in multiple deposition operations). For example, metal layer 626 may be formed of titanium, tungsten, copper, aluminum, and / or other known metals.

[0115] like Fig. 6F As shown, sacrificial layers 600 and 620 may then be removed to release bridge 302 and vertical legs 308 still suspended above the ROIC with space 650 between the vertical legs and the ROIC. Fig. 6FThe vertical legs 308 appear to be floating, but this is only because of the particular cross-section of the device shown. Those skilled in the art will appreciate that Fig. 6F The vertical leg 308 along Fig. 6F The XY plane is extended, for example, as Figure 3 As shown, the metal layer 626 forms a continuous conductive path between the bridge contact 306 and the contact 310 . Fig. 6F The vertical leg 308 may include at least a portion that extends non-perpendicularly to a plane defined by the surface 699 of the base plate 602. For example, the vertical leg 308 may extend along a path that is parallel to the surface 699. In another embodiment, the vertical leg 308 may extend along a path that includes a portion that is parallel to the surface 699 and an additional portion that bends downwardly toward the surface 699 at a non-perpendicular angle.

[0116] Figures 6A-6F The process shown is illustrative only. According to different embodiments, the vertical legs of the microbolometer array can be formed using other processes. For example, in one embodiment, a process such as Figures 7A-7F The process shown in FIG. 1 is to form a vertical leg arranged below the plane forming the bridge 302 (eg, with Fig. 6F In contrast to the vertical leg of the connector, the vertical leg is arranged substantially in a common plane with the bridge 302).

[0117] Now turn to Fig. 7A , shows a portion 701 of a microbolometer array having contacts 310 and a bridge 302. As shown, the bridge 302 includes a sensor layer (e.g., a temperature-sensitive resistive material layer such as VO x ) 709 and one or more additional layers 707 (such as an absorption layer). As shown, the contact 310 can be formed by a vertical conductive portion (such as a metal stud 708) and one or more layers (such as a metal contact layer 714 in contact with the metal stud 708). The contact 310 can include additional layers (such as a dielectric layer 716 disposed above the metal layer 714) and additional layers 712 (such as a passivation layer disposed below multiple portions of the metal layer 714). As shown, the passivation layer 712 can be formed on a portion of the top surface 703 of the sacrificial layer 700.

[0118] Sacrificial layer 700 may be formed of, for example, polyimide. Layers 712 and 716 may be formed of, for example, silicon dioxide or silicon nitride. Metal layer 714 may be formed of titanium, tungsten, copper, aluminum, and / or other known metals.

[0119] The metal stud 708 (or in some cases, a basket contact) can be conductively coupled to a conductive contact, such as a contact 750 of a readout integrated circuit (ROIC), such as a complementary metal oxide semiconductor (CMOS) ROIC. Fig. 7A In an embodiment of the present invention, the contact 750 is disposed in a glass cover layer 702 (e.g., a CMOS glass cover layer) of the ROIC. Before forming the vertical legs between the bridge 302 and the contact 310, the bridge 302 can be disposed on a sacrificial layer 700 that supports the bridge 302 and fills the gap between the bridge of the microbolometer array and the ROIC and extends continuously between the bridge of the microbolometer array and the contact.

[0120] According to one embodiment, a process for forming a vertical leg between the bridge 302 and the contact 310 may include forming an opening 704 in the sacrificial layer 700 supporting the bridge 302 (eg, by etching through the surface 703), such as Figure 7B As shown. The opening 704 can be formed in a portion of the sacrificial layer 700 that is at least partially disposed between the bridge 302 and the contact 310, such that the opening 704 has vertical sidewalls 705 at different locations between the bridge 302 and the contact 310. As shown, the sidewalls 705 can be substantially below the plane defined by the bridge 302 (e.g., Figure 7B XY plane).

[0121] like Figure 7C As shown, dielectric layer 706 may be deposited and patterned so that portions of dielectric layer 706 remain on sidewalls 705 of sacrificial layer 700 in opening 704. Fig.7D As shown, openings, such as opening 713 in layer 707 of bridge 302 and dielectric layer 716, may also be formed to expose portions of sensor layer 709 and metal layer 714, respectively.

[0122] Then, if Fig. 7E As shown, a metal layer (e.g., leg metal layer 710) is deposited over the contacts 310, portions of the sacrificial layer 700, the dielectric layer 706 on the sidewalls 705, and the bridge 302. The metal layer 710 can be deposited during a blank deposition process. As shown, portions of the metal layer 710 can be formed within the openings 713 (see FIG. Fig.7D ) and contacts the sensor layer 709 and the metal layer 714.

[0123] Additional dielectric layer 711 ( Figure 7F) may be deposited over the metal layer 710, and the metal layer 710 and the additional dielectric layer 711 may be etched (e.g., in a masked spacer etching process) to remove portions of the metal layer 710 and the additional dielectric layer 711 from the sacrificial layer 700. In this manner, a dielectric-metal-dielectric stack may be vertically formed on the sidewalls 705 of the opening 704, and portions of the dielectric-metal-dielectric stack continuously coupled to portions on the sidewalls 705 may also remain on the contact 310 and the bridge 302, thereby forming the bridge contact 306 and a leg metal contact to the metal layer 714 of the contact 310.

[0124] Dielectric layers 706 and 711 may be formed of, for example, silicon dioxide or silicon nitride. Metal layer 710 may be a single metal layer, forming a homogeneous film of a single material, or may include multiple materials (e.g., multiple layers of the same or different materials formed in multiple deposition operations). For example, metal layer 710 may be formed of titanium, tungsten, copper, aluminum, and / or other known metals.

[0125] like Figure 7F As shown, the sacrificial layer 700 can then be removed to release the bridge 302 and vertical leg 308 formed by the metal layer 710 and the dielectric layers 706 and 711 that partially surround the metal layer 710. As shown, the vertical leg 308 is still suspended above the ROIC with a space 720 between the vertical leg and the ROIC. In this way, the vertical leg 308 can be perpendicular to the ROIC. Figure 7F The XY plane is formed and along the path (for example, Figure 3 The path is arranged between the bridge 302 and the contact 310. Figure 7F 308 so that metal layer 710 forms a continuous conductive path between bridge contact 306 and contact 310 through leg 308 .

[0126] Figure 7F The vertical leg 308 may include at least a portion that does not extend perpendicularly to a plane defined by the surface 799 of the base plate 702. For example, the vertical leg 308 may continue along a path that is parallel to the surface 799. In another embodiment, the vertical leg 308 may continue along a path that includes a portion that is parallel to the surface 799 and an additional portion that bends downwardly toward the surface 799 at a non-perpendicular angle.

[0127] exist Figure 7FIn an embodiment, the legs coupling the bridge 302 to the contact 310 may include a vertical portion 308 and a horizontal portion 718 extending between the bridge 302 and a first end of the vertical leg 308 and between a second opposing end of the vertical leg 308 and the contact 310. In various embodiments, the legs 308 may include any suitable combination of vertical and horizontal portions to provide adequate performance for the microbolometer while avoiding reducing the fill factor of the microbolometer array due to the area occupied by the legs.

[0128] Figures 8A-8C are cross-sectional side views of a portion of a microbolometer array at various stages during vertical leg formation, illustrating an alternative process for vertical leg formation.

[0129] Now turn to Fig. 8A , a portion 801 of a microbolometer array is shown having a contact 310 and a bridge 302. As shown, the bridge 302 includes a sensor layer (e.g., a temperature-sensitive resistive material layer such as VOx) 806 and one or more additional layers 807 (e.g., an absorption layer). As shown, the contact 310 may be formed by a vertical conductive portion such as a metal stud 803 and one or more layers (e.g., a metal contact layer 814 in contact with the metal stud 803). The contact 310 may include additional layers (e.g., a dielectric layer 816 disposed above the metal layer 814) and additional layers 812 (e.g., a passivation layer disposed under a portion of the metal layer 814 and covering the top surface of the sacrificial layer 800). The passivation layer 812 may extend between the bridge 302 and the contact 310 on the top surface sacrificial layer 800.

[0130] Sacrificial layer 800 may be formed of, for example, polyimide. Layers 812 and 816 may be formed of, for example, silicon dioxide or silicon nitride. Metal layer 814 may be formed of titanium, tungsten, copper, aluminum, and / or other known metals.

[0131] The metal stud 803 (or in some cases, the basket contact) can be conductively coupled to a conductive contact, such as a contact 809 of a readout integrated circuit (ROIC) (such as a complementary metal oxide semiconductor (CMOS) ROIC). Fig. 8A In an embodiment, the contact 809 is disposed on a glass cover layer 802 (e.g., a CMOS glass cover layer) of the ROIC. Before forming the vertical legs between the bridge 302 and the contact 310, the bridge 302 can be disposed on a sacrificial layer 800 that supports the bridge 302 and fills the gap between the microbolometer array and the bridge of the ROIC and extends continuously between the bridge of the microbolometer array and the contact.

[0132] According to one embodiment, a process for forming a vertical leg between the bridge 302 and the contact 310 may include forming an opening 804 in a sacrificial layer 800 supporting the bridge 302 and in a passivation layer 812 disposed on the sacrificial layer, such as Fig. 8A An opening 804 can be formed in a portion of the sacrificial layer 800 and the passivation layer 812 that is at least partially disposed between the bridge 302 and the contact 310 so that the opening 804 has vertical sidewalls 805 at different locations between the bridge 302 and the contact 310. As shown, the sidewalls 805 can be formed by a portion of the sacrificial layer 800 and the passivation layer 812.

[0133] Then, before depositing dielectric layer 810 (over metal layer 808) (e.g., over contacts 310, on portions of the top surface of passivation layer 812, on sidewalls 805 in contact with sacrificial layer 800 and passivation layer 812, on portions of sacrificial layer 800 in opening 804, and on bridge 302), a metal layer (e.g., leg metal layer 808) may be deposited, and metal layer 808, dielectric layer 810, and passivation layer 812 may be patterned (e.g., in a masked spacer etch process) so that metal layer 808 remains on some sidewalls of opening 804, such as the sidewalls of the opening 804. Figure 8B In this way, metal legs may be vertically formed on some sidewalls of the opening 804 , and a horizontal portion 818 having the metal layer 808 between the passivation layer 812 and the dielectric layer 810 may also remain on the sacrificial layer 800 .

[0134] For example, dielectric layer 810 may be formed of silicon dioxide or silicon nitride. Metal layer 808 may be a single metal layer forming a uniform thin film of a single material, or may include multiple materials (e.g., multiple layers of the same or different materials formed in multiple deposition operations). For example, metal layer 808 may be formed of titanium, tungsten, copper, aluminum, and / or other known metals.

[0135] like Figure 8C As shown, the sacrificial layer 800 can then be removed to release the bridge 302 and the vertical leg 308 having the horizontal portion 818. As shown, the vertical leg 308 including the horizontal portion 818 is still suspended above the ROIC, with a space 820 between the vertical leg and the ROIC. Figure 8C The vertical legs 308 including the horizontal portion 818 may be less prone to movement and / or damage than legs having only vertical portions. The vertical legs 308 including the horizontal portion 818 may form a continuous conductive path between the bridge contact 306 and the contact point 310 through the legs 308.

[0136] Figure 8CThe vertical leg 308 may include at least a portion that does not extend perpendicularly to a plane defined by the surface 899 of the base plate 802. For example, the vertical leg 308 may extend along a path that is parallel to the surface 899. In another embodiment, the vertical leg 308 may extend along a path that includes a portion that is parallel to the surface 899 and another portion that bends downwardly toward the surface 899 at a non-perpendicular angle.

[0137] It is understandable that the above Figures 6A-8C The related processes may be modified, rearranged and / or omitted to form vertical bolometer legs having various shapes, sizes, orientations and arrangements to meet the needs of various purposes. Fig. 9 , 10 , 11, 12, 13A-13Q, 14 and 15 show various arrangements of vertical legs and associated contacts or bridges that can be formed for a microbolometer array. In particular, Fig. 9 and Fig.10 Portions of a microbolometer array are shown (before release by removal of a sacrificial layer) with vertical legs of the array formed below the plane of the bridge near the contacts of the microbolometers and the bridge, respectively, according to one embodiment. Fig.11 and 12 Portions of a microbolometer array according to another embodiment are shown having vertical legs formed below the plane of the bridge near contacts and bridges of the microbolometers, respectively. Figures 13A-13Q Various arrangements of metal and insulation for the vertical legs of the microbolometer are shown. Fig.14 and 15 Portions of a microbolometer array having vertical legs formed on or above the face of a bridge in the vicinity of contacts and bridges of the microbolometers, respectively, are shown according to another embodiment.

[0138] like Fig. 9 As shown, at a particular stage of production, a portion of the metal layer 714 may be formed on the sacrificial layer 700, and a portion of the dielectric layer 706 may extend onto the portion of the metal layer 714 formed on the sacrificial layer, over the vertical portion of the metal layer 714 formed on the stud 708, and over the horizontal portion of the metal layer 714 formed on the top of the stud 708, such that the portion of the dielectric layer 706 disposed over the top surface of the sacrificial layer 700 is symmetrical on multiple sides of the stud 708. Then, the sacrificial layer 700 may be removed.

[0139] According to one embodiment, the contact 310 is generated Fig. 9 The process of structure can also form Fig.10 The bridge shown. Fig.10 As shown, the bridge 302 may include bridge dielectric layers 1000 and 1002 disposed on opposite sides of the sensor layer 606. The dielectric layer 706 may extend vertically from the vertical leg structure 308 and cover a portion of the bridge dielectric 1002. The metal layer 710 may cover the portion of the dielectric layer 706 extending vertically from the vertical leg structure 308 and covering the bridge dielectric 1002, and the metal layer may extend through the bridge dielectric 1002 and the leg dielectric 706 to the contact sensor layer 606.

[0140] In another embodiment, Fig.11 As shown, metal layer 710 may be asymmetrical around the top of stud 708 so that metal layer 710 remains in contact with metal layer 714 forming contact 310 on one side of vertical leg 308 on stud 708, thereby increasing the contact area between layers 710 and 714. Fig.11 After the structure is shown, the sacrificial layer 700 may be removed.

[0141] According to one embodiment, the contact 310 is caused Fig.11 The process of structure can also form Fig.12 The bridge shown. Fig.12 As shown, a portion of the metal layer 710 may be formed directly on a portion of the bridge dielectric 1002 , such that the metal layer 710 passes through the portion of the bridge dielectric 1002 and contacts the sensor layer 606 through the bridge dielectric 1002 .

[0142] Figures 13A-13Q 2 and 3 show cross-sectional views of exemplary embodiments of vertical bolometer legs, such as the vertical legs 308 described herein. Fig.13A As shown, the vertical bolometer leg may include a substantially vertical conductive (eg, metal) layer 1300 disposed between first and second substantially vertical dielectric layers 1302 and 1304, the dielectric layers having a common height H with the vertical conductive layer 1300. Fig.13A In a configuration of , the vertical legs can have a width that is substantially the same along the height of the vertical legs and substantially equal to the sum of the widths of layers 1300 , 1302 , and 1304 .

[0143] In general, a vertical bolometer leg may have: a first dimension (e.g., height H) extending in a direction perpendicular to a plane defined by an associated bolometer bridge and / or substrate; a second dimension (e.g., width W) extending in a direction parallel to the plane of the bridge and / or substrate; and a third dimension extending along and defining a signal path, wherein the path may include a portion extending in a direction parallel to the plane of the bridge and / or substrate, and the second dimension is substantially smaller than the first dimension.

[0144] like Fig. 13B As shown, in one embodiment, dielectric layer 1302 may extend above the top of conductive layer 1300 and extend horizontally above the top of conductive layer 1300 and dielectric layer 1304. Fig. 13C As shown, in one embodiment, conductive layer 1300 may have a height that is less than a height of dielectric layer 1302 , and dielectric layer 1302 may extend below the bottom of conductive layer 1300 and dielectric layer 1304 .

[0145] like Fig.13D As shown, in one embodiment, dielectric layer 1302 may extend above the top of conductive layer 1300 and extend horizontally on top of conductive layer 1300 and dielectric layer 1304, and conductive layer 1300 may have a height shorter than the height of dielectric layer 1302, and dielectric layer 1304 may extend below the bottom of conductive layer 1300 to dielectric layer 1302. Fig.13E As shown, in one embodiment, conductive layer 1300 may have a height shorter than the height of dielectric layer 1302, dielectric layer 1304 may extend below the bottom of conductive layer 1300 to dielectric layer 1302, and horizontal dielectric layer 1306 may cover the tops of layers 1300, 1302 and 1304.

[0146] like Fig.13F As shown, in one embodiment, conductive layer 1300 and dielectric layers 1302 and 1304 may have a common height, and horizontal dielectric layer 1306 may cover the tops of layers 1300, 1302, and 1304. Figure 13G As shown, in one embodiment, the conductive layer 1300 may have a vertical portion and a horizontal portion, so that the conductive layer has an "L" shape in cross section. Figure 13G In the configuration, dielectric layer 1304 extends vertically along the vertical portion of conductive layer 1300 and extends horizontally under the vertical and horizontal portions of conductive layer 1300, and dielectric layer 1302 extends vertically along the vertical portion of conductive layer 1300, extends horizontally on top of the horizontal portion of conductive layer 1300, and vertically passes through the horizontal portion of conductive layer 1300 to the bottom of the vertical leg.

[0147] like Fig.13H As shown, in one embodiment, the conductive layer 1300 may be free of any surrounding dielectric material. Fig.13I As shown, in one embodiment, the conductive layer 1300 may have one side covered by the dielectric layer 1304 and an opposite side without dielectric material. Fig.13JAs shown, in one embodiment, the height of the conductive layer 1300 having one side covered by the dielectric layer 1302 and the other side free of dielectric material can be shorter than the height of the vertical legs, and the dielectric layer 1302 can extend below the bottom of the conductive layer 1300. Figure 13K As shown, in one embodiment, conductive layer 1300 having one side covered by dielectric layer 1302 and an opposite side free of dielectric material may have a vertical portion and a horizontal portion extending over the top of dielectric layer 1302 .

[0148] like Figure 13L As shown, in one embodiment, a conductive layer 1300 having one side covered by a dielectric layer 1304 and an opposite side free of dielectric material may have a first vertical portion, a horizontal portion extending over the top of the dielectric layer 1304, and a second vertical portion offset from the first vertical portion. Figure 13L In the configuration of , dielectric layer 1304 may have a vertical portion extending along a first vertical portion of conductive layer 1300 and a horizontal portion extending below the first vertical portion of conductive layer 1300 to a second vertical portion of conductive layer 1300 .

[0149] like Figure 13M As shown, the conductive layer 1300 may include a vertical portion and a horizontal portion 1308, the horizontal portion horizontally extending from the bottom of the vertical portion of the conductive layer 1300, so that the conductive layer 1300 and the horizontal portion 1308 form an "L" shape. Figure 13M In the embodiment of the present invention, the conductive layer 1300 is covered by a dielectric (insulating) layer 1302 on a first side, by a dielectric (insulating) layer 1304 on another side, and by insulation (dielectric layer 1312) along the bottom surface of the horizontal portion 1308.

[0150] like Fig.13N As shown, in one embodiment, the horizontal portion 1308 and the portion below the top surface of the vertical portion can be substantially surrounded by one or more dielectric layers (such as dielectric layers 1302, 1304 and 1312) so that there is no dielectric material on the top of the vertical portion of the conductive layer 1300.

[0151] like Fig.13O As shown, in one embodiment, the conductive portion 1300 may have a vertical portion, a first horizontal portion extending from the top of the vertical portion in a first direction, a second horizontal portion extending from the bottom of the vertical portion in an opposite second direction, and an additional portion filling a space below a horizontal dielectric layer 1304 formed below the first horizontal portion. Fig.13OIn the configuration, the tops of the first horizontal portion, the vertical portion, and the second horizontal portion of the conductive layer 1300 are covered on one side by the dielectric layer 1302.

[0152] like Figure 13P As shown, in one embodiment, the conductive layer 1300 may have a vertical portion, a first horizontal portion extending from the top of the vertical portion in a first direction, and a second horizontal portion extending from the bottom of the vertical portion in an opposite second direction. Figure 13P In the configuration of FIG. 1 , the top of the first horizontal portion, the vertical portion, and the second horizontal portion of the conductive layer 1300 are covered on one side by the dielectric layer 1302, and the dielectric layer 1304 extends below the first horizontal portion of the conductive layer 1300 and fills the space. Figure 13Q As shown, a conductive layer having a vertical portion, a first horizontal portion extending from a top of the vertical portion in a first direction, and a second horizontal portion extending from a bottom of the vertical portion in an opposite second direction may be substantially surrounded by insulating material 1312 .

[0153] like Fig.14 As shown, at a particular stage of production of a vertical bolometer leg formed above and perpendicular to a surface 603 of a sacrificial layer such as sacrificial layer 600 (e.g., a sacrificial layer on which a bridge structure of one or more microbolometers is formed), a portion of a metal layer 614 may be formed on the sacrificial layer 600, and a portion of a dielectric layer 624 may extend over the portion of the metal layer 614 formed on the sacrificial layer, over the vertical portion of the metal layer 614 over the stud 608, and over the horizontal portion of the metal layer 614 over the top of the stud 608. The dielectric layer 624, the leg metal layer 626, and the dielectric layer 628 may form a horizontal portion 1400 that extends horizontally from the contact 310 and turns vertically to form the vertical leg portion 308. The sacrificial layer 600 may then be removed.

[0154] According to one embodiment, the contact 310 is formed Fig.14 The process of forming a structure can also be Fig.15 The bridge shown. Fig.15 As shown, the bridge 302 may include bridge dielectric layers 1500 and 1502 disposed on opposite sides of the sensor layer 606. The dielectric layer 624, the metal layer 626, and the dielectric layer 628 may form a stack including the vertical leg portion 308 and a portion 1504 extending horizontally from the vertical leg portion 308 to the bridge 302. As shown, the metal layer 626 may cover a portion of the dielectric layer 624 extending horizontally from the vertical leg structure 308 and a portion of the bridge dielectric 1502, and may contact the sensor layer 606 through the bridge dielectric 1502 and the leg dielectric 624.

[0155] Fig.16 A top view of a portion of vertical leg 308 in bend region 312 is shown. Fig.17 and 18 Shown along Fig.16 A cross-sectional side view of an exemplary embodiment of the curved region 312 cut along the xx line. Fig.17 As shown, according to one embodiment, the bending region 312 may include a pad 1700 formed at the bottom of the vertical conductive layer 1702, which is inserted between the vertical dielectric layers 1704 and 1706 of the vertical legs. The pad 1700 may be formed of metal, dielectric material, or a combination of metal and dielectric materials (as examples). Fig.18 As shown, according to one embodiment, the bending region 312 may include a metal pad 1800 formed on top of the vertical conductive layer 1702 and the vertical dielectric layers 1704 and 1706 of the vertical legs. The pad 1800 may be formed of metal, dielectric material, or a combination of metal and dielectric materials (as examples).

[0156] Fig.19 is a cross-sectional side view of a portion of a microbolometer array at a particular stage of production, illustrating how, in one embodiment, at least a portion of a vertical leg structure may be formed below a bridge 302 of a microbolometer. Fig.19 As shown, the bridge 302 may include a sensor layer 606 disposed between bridge dielectric layers 1908 and 1910. The bridge dielectric layer 1910 may be formed on a first sacrificial layer 1904 interposed between the bridge dielectric layer 1910 and a vertical leg structure 1906 beneath the bridge dielectric layer 1910 and a cover glass 1902 of an ROIC for a microbolometer array. Fig.19 At the production stage shown, the second sacrificial layer 1900 may be disposed between the vertical leg structures 1906 and the cover glass 1902 .

[0157] exist Fig.19In the illustrated configuration, the sensor layer 606 of the bridge 302 includes a vertical portion that extends downward from the bridge 302 and turns in a horizontal direction to form a portion of the bridge contact 306. As shown, a conductive layer (such as conductive layer 1911) can couple the sensor material 606 in the bridge contact area 306 to a vertical leg structure 1906. The vertical leg structure 1906 can extend to a contact, such as a stud contact or a basket contact, coupling the vertical leg structure 1906 to a contact on the ROIC (e.g., a contact formed partially or completely within the cover glass layer 1902). The vertical leg structure 1906 can be coupled to a dedicated contact structure of the bridge 302 formed thereunder, and / or can be coupled to a shared contact with an adjacent microbolometer.

[0158] Fig. 20 is a flow chart of illustrative operations that may be used to form vertical microbolometer legs for coupling a microbolometer bridge to a ROIC contact structure, according to one embodiment.

[0159] At block 2000, an imaging device having a contact structure and a bolometer bridge structure (e.g., a microbolometer bridge structure) may be provided. The imaging device may include a partially fabricated focal plane array on which a sacrificial layer such as a polyimide layer is formed on a substrate such as a readout integrated circuit, and the bridge structure is formed on the sacrificial layer. In some embodiments, an etch stop layer may be formed on the sacrificial layer. However, in other embodiments, the sacrificial layer may not contain any etch stop material. The contact structure may include electrical contacts on the readout integrated circuit and, if desired, conductive elements extending from the electrical contacts on the ROIC to part or all of the sacrificial layer. The conductive elements may include studs or basket contacts and, if desired, may also include one or more additional structures such as a passivation layer, a metal layer, and / or a dielectric layer formed on the conductive elements.

[0160] At block 2002, an additional sacrificial layer may be deposited and patterned over or on the sacrificial layer. In an embodiment, an etch stop layer is provided on the sacrificial layer, and the additional sacrificial layer may be deposited on the etch stop layer so that portions of the etch stop layer are formed between the sacrificial layer and the additional sacrificial layer. Patterning of the additional sacrificial layer may include etching the additional sacrificial layer so as to form an opening in the additional sacrificial layer at least partially between the bridge structure and the contact structure.

[0161] At block 2004, a first leg dielectric material may be formed at least on the sidewalls of the opening in the patterned additional sacrificial layer. Forming the first leg dielectric material on the sidewalls of the opening may include depositing a first leg dielectric layer and performing a spacer etching of the first leg dielectric layer. The etching may also leave portions of the first leg dielectric layer on portions of the contact structure and / or the bridge structure as desired.

[0162] At block 2006, one or more conductive layers (such as leg metal layers) may be deposited (e.g., using blanket metal deposition) and patterned on the first leg dielectric material on the sidewalls of the opening and over at least some of the contact structures and the bridge structure. The leg metal layers may be formed in contact with the metal layers of the contact structures and the sensor layer of the bridge structure.

[0163] A second leg dielectric layer may be deposited and patterned on the metal layer at block 2008. Patterning of the second leg dielectric layer may include depositing the second leg dielectric layer over the leg metal layer before patterning the leg metal layer and performing in-situ dielectric and metal etching of the leg metal layer and the second leg dielectric layer.

[0164] At block 2010, the sacrificial layer and additional sacrificial layers may be removed to release the bridge structure and the vertical leg structure formed by the first and second leg dielectric layers and the leg metal layer so that the bridge and the legs are suspended above the readout integrated circuit and the contact structure is coupled to the bridge structure through the vertical leg structure. In an embodiment, an etch stop layer is disposed on the sacrificial layer, and portions of the etch stop layer may also be removed.

[0165] Fig.21 is a flow chart of illustrative operations that may be used to form vertical microbolometer legs for coupling a microbolometer bridge to a ROIC contact structure, according to another embodiment.

[0166] At block 2100, an imaging device having a contact structure and a bolometer bridge structure (e.g., a microbolometer bridge structure) may be provided. The imaging device may include a partially fabricated focal plane array on which a sacrificial layer (e.g., a polyimide layer) is formed on a readout integrated circuit and the bridge structure is formed on the sacrificial layer. The contact structure may include electrical contacts on the readout integrated circuit and, if desired, conductive elements extending from the electrical contacts on the ROIC to part or all of the sacrificial layer. The conductive elements may include studs or basket contacts and, if desired, one or more additional structures such as a passivation layer, a metal layer, and / or a dielectric layer may also be formed on the conductive elements.

[0167] At block 2102 , the sacrificial layer may be etched to form an opening in the sacrificial layer at least partially between the bridge structure and the contact structure.

[0168] At block 2104, a first leg dielectric material may be formed at least on the sidewalls of the opening in the sacrificial layer. Forming the first leg dielectric material on the sidewalls of the opening may include depositing a first leg dielectric layer and performing a spacer etch of the first leg dielectric layer. The etch may also be performed to leave desired portions of the first leg dielectric layer on portions of the contact structure and / or bridge structure.

[0169] At block 2106, openings may be formed in the dielectric layers of the contact structures and the bridge structures. Forming the openings in the dielectric layers of the contact structures and the bridge structures may expose portions of the metal layers of the contact structures and / or the sensor layers of the bridge structures.

[0170] At block 2108, one or more conductive layers (such as leg metal layers) may be deposited (e.g., using blanket metal deposition) and patterned on the first leg dielectric material on the sidewalls of the opening and over at least some of the contact structures and the bridge structure. The leg metal layers may be formed in contact with exposed portions of the metal layers of the contact structures and the sensor layer of the bridge structure.

[0171] A second leg dielectric layer may be deposited and patterned on the metal layer at block 2110. Patterning of the second leg dielectric layer may include depositing the second leg dielectric layer on the leg metal layer before patterning the leg metal layer and performing in-situ dielectric and metal etching on the leg metal layer and the second leg dielectric layer.

[0172] At block 2112 , the sacrificial layer may be removed to release the bridge structure and the vertical leg structure formed by the first and second leg dielectric layers and the leg metal layer so that the bridge and legs are suspended above the readout integrated circuit and the contact structure is coupled to the bridge structure through the vertical leg structure.

[0173] Fig. 22 is a flow chart of illustrative operations that may be used to form vertical microbolometer legs for coupling a microbolometer bridge to a ROIC contact structure, according to another embodiment.

[0174] At block 2200, an imaging device having a contact structure and a bolometer bridge structure (e.g., a microbolometer bridge structure) may be provided. The imaging device may include a partially fabricated focal plane array having a sacrificial layer (e.g., a polyimide layer) formed on a readout integrated circuit, a passivation layer formed on at least a portion of the sacrificial layer, and a bridge structure formed on the sacrificial layer. The contact structure may include electrical contacts on the readout integrated circuit and, if desired, conductive elements extending from the electrical contacts on the ROIC to part or all of the sacrificial layer. The conductive elements may include studs or basket contacts and, if desired, one or more additional structures, such as a portion of a passivation layer, a metal layer, and / or a dielectric layer formed over the conductive elements.

[0175] At block 2202 , the sacrificial layer and the passivation layer may be etched to form an opening in the sacrificial layer and the passivation layer at least partially between the bridge structure and the contact structure.

[0176] At block 2204 , one or more conductive layers, such as a leg metal layer, may be deposited (eg, using blank metal deposition) and patterned on sidewalls of the opening and over portions of the passivation layer on at least some of the contact structures, bridge structures, and sacrificial layer.

[0177] A leg dielectric layer may be deposited and patterned on the metal layer at block 2206. Patterning of the leg dielectric layer may include depositing the leg dielectric layer on the leg metal layer prior to patterning of the leg metal layer and performing in-situ dielectric and metal etching of the leg metal layer and the second leg dielectric layer.

[0178] At block 2208, the sacrificial layer may be removed to release the bridge structure and the vertical leg structure formed by portions of the passivation layer, the leg dielectric layer, and the leg metal layer so that the bridge and the legs are suspended above the readout integrated circuit and the contact structure is coupled to the bridge structure through the vertical leg structure.

[0179] The process for forming the vertical microbolometer legs described above is merely illustrative. According to different embodiments, the vertical legs of the microbolometer array may be formed using other processes. For example, in one embodiment, a process such as Figures 23A-23F The process shown uses an etch stop layer to form the vertical legs.

[0180] Figures 23A-23F Shown are cross-sectional side views of a portion of a microbolometer array at various stages during the production of a microbolometer leg for the microbolometer array.

[0181] Now turn to Fig.23A, a portion 2398 of a microbolometer array is shown having a contact 310 and a bridge 302. As shown, the bridge 302 includes a sensor layer (e.g., a temperature-sensitive resistive material layer, such as VOx) 2306 and one or more additional layers 2304, such as an absorption layer. As shown, the contact 310 may be formed by a vertical conductive portion such as a metal stud 2308 and one or more layers such as a metal contact layer 2314 in contact with the metal stud 2308. The contact 310 may include additional layers such as a passivation layer 2316 disposed below portions of the metal layer 2314. As shown, additional layers such as an etch stop layer 2303 (e.g., a layer of dielectric material) may be formed on the sacrificial layer 2300 and may extend to form a portion of the bridge 302 and / or the contact 310.

[0182] Sacrificial layer 2300 may be formed of, for example, polyimide. Layers 2303 and 2316 may be formed of, for example, silicon dioxide or silicon nitride. Metal layer 2314 may be formed of titanium, tungsten, copper, aluminum, and / or other known metals.

[0183] The metal stud 2308 can be conductively coupled to a conductive contact, such as a contact 2310 of a substrate, such as a readout integrated circuit (ROIC) substrate, such as a complementary metal oxide semiconductor (CMOS) ROIC. Fig.23A In an embodiment, the contact 2310 is disposed on a cover glass layer 2302 (e.g., a CMOS cover glass layer) of the ROIC. Before forming the vertical legs between the bridge 302 and the contact 310, the bridge 302 can be arranged on the sacrificial layer 2300 so that the sacrificial layer 2300 fills the gap between the bridge of the microbolometer array and the ROIC and extends continuously between the bridge of the microbolometer array and the contact.

[0184] According to one embodiment, the process for forming the vertical leg between the bridge 302 and the contact 310 may include depositing and patterning an additional sacrificial layer 2320 on the etch stop layer 2303, such as Fig. 23B The patterning of the additional sacrificial layer 2320 may include forming an opening 2322 in the additional sacrificial layer (e.g., at least partially between the bridge 302 and the contact 310) so that the remaining portion of the additional sacrificial layer 2320 has vertical sidewalls 2325. The opening 2322 may extend to the top surface 2301 of the etch stop layer 2303.

[0185] After the deposition and patterning of the additional sacrificial layer 2320, a dielectric layer 2324 may be deposited and patterned so that portions of the dielectric layer 2324 remain on the sidewalls 2325 of the additional sacrificial layer 2320 in the opening 2322, such as Fig.23C Then, as Fig.23DAs shown, a metal layer, such as leg metal layer 2326, can be deposited on the contacts 310, portions of the etch stop layer 2303, the dielectric layer 2324 on the sidewalls 2325, portions of the additional sacrificial layer 2320, and the bridge 302. If desired, openings can be formed in portions of the etch stop layer 2303 that are arranged on the contacts 310 and the bridge 302 to expose portions of the metal layer 2314 and the sensor layer 2306 so that the metal layer 2326 can be deposited in contact with the metal layer 2314 and the sensor layer 2306. The metal layer 2326 can be deposited in a blank deposition process.

[0186] like Fig.23E As shown, an additional dielectric layer 2328 may be deposited on the metal layer 2326, and then the metal layer 2326 and the additional dielectric layer 2328 may be etched (e.g., in a masked spacer etch process) to remove portions of the metal layer 2326 and the additional dielectric layer 2328 from the etch stop layer 2303 and the additional sacrificial layer 2320. In this manner, a dielectric-metal-dielectric stack may be formed vertically on the sidewalls 2325 of the opening 2322. Portions of the dielectric-metal-dielectric stack that are continuously coupled to the portions on the sidewalls 2325 may also remain on the contact 310 and the bridge 302, thereby forming the bridge contact 306 and the leg metal in contact with the metal layer 2314 of the contact 310.

[0187] Dielectric layers 2324 and 2328 may be formed of silicon dioxide or silicon nitride as examples. Metal layer 2326 may be a single metal layer forming a homogeneous film of a single material, or may include multiple materials (e.g., multiple layers of the same or different materials formed in multiple deposition operations). For example, metal layer 2326 may be formed of titanium, tungsten, copper, aluminum, and / or other known metals.

[0188] like Fig.23F As shown, portions of the sacrificial layers 2300 and 2320 and the etch stop layer 2303 may be removed to release the bridge 302 and vertical legs 308 suspended above the ROIC with a space 2350 between the vertical legs and the ROIC. Fig.23F The vertical leg 308 may include at least a portion that extends non-perpendicularly to the plane defined by the surface 2399 of the base plate 2302. For example, the vertical leg 308 may extend along a path parallel to the surface 2399. In another embodiment, the vertical leg 308 may extend along a path that includes a portion parallel to the surface 2399 and an additional portion that bends downwardly toward the surface 2399 at a non-perpendicular angle.

[0189] Fig.24A cross-sectional side view of a microbolometer bridge coupled with legs formed under the bridge is shown according to one embodiment. Fig.24 In the embodiment of the present invention, the bridge 302 includes a sensor layer 2400 formed generally between bridge dielectric layers 2402 and 2404. The sensor layer 240 (eg, a temperature-sensitive resistive material such as VO x ) may include one or more horizontal portions extending in a plane parallel to the surface of the substrate on which the bridge 302 is formed, and may include a plurality of portions 2406 extending downwardly from the horizontal portions in the direction of the substrate (e.g., perpendicular to the surface of the substrate). Portions 2406 may extend to contact one or more legs, such as legs 2420 formed below the bridge 302 (e.g., at least partially disposed between the bridge 302 and the substrate above which the bridge is placed).

[0190] like Fig.24 As shown, the leg 2420 formed of the conductive material has a horizontal portion 2408 in contact with the sensor layer 2306 and a vertical portion 2410 extending perpendicular to the horizontal portion 2408. However, this is merely illustrative. In various embodiments, the leg 2420 may include vertical and / or horizontal portions and / or may be partially or completely covered in an insulating material, such as in any of the embodiments described herein.

[0191] To form Fig.24 For a bridge of the type shown, illustrative operations may be performed in Fig.25 Shown in.

[0192] At block 2500, an imaging device having a contact structure formed on and / or in a sacrificial layer may be provided. The imaging device may include a partially fabricated focal plane array on which a sacrificial layer, such as a polyimide layer, is formed on a substrate, such as a readout integrated circuit substrate. The contact structure may include electrical contacts on the substrate and, if desired, conductive elements extending from the electrical contacts on the ROIC to part or all of the sacrificial layer. The conductive elements may include studs or basket contacts and, if desired, one or more additional structures formed above the conductive elements, such as a passivation layer, a metal layer, and / or a dielectric layer.

[0193] At block 2502, an opening may be formed in a sacrificial layer.

[0194] At block 2504, a first leg dielectric material may be formed at least on sidewalls of the opening in the sacrificial layer. Forming the first leg dielectric material on the sidewalls of the opening may include depositing a first leg dielectric layer and performing a spacer etch of the first leg dielectric layer.

[0195] At block 2506, one or more conductive layers (e.g., leg metal layers) can be deposited (e.g., using blanket metal deposition) and patterned over the first leg dielectric material on the sidewalls of the opening and over at least some of the contact structures. The leg metal layers can be formed in contact with the metal layers of the contact structures.

[0196] A second leg dielectric layer may be deposited and patterned on the leg metal layer at block 2508. Patterning of the second leg dielectric layer may include depositing the second leg dielectric layer over the leg metal layer prior to patterning the leg metal layer and performing in-situ dielectric and metal etching of the leg metal layer and the second leg dielectric layer.

[0197] At block 2510, an additional sacrificial layer may be deposited over the sacrificial layer.

[0198] At block 2512, one or more bolometer bridge contacts may be formed in the second sacrificial layer.

[0199] At block 2514, a first bridge dielectric layer may be deposited.

[0200] At block 2516, one or more contacts may be formed in an underlying second leg dielectric layer over the first bridge dielectric layer and the leg metal layer for connection to the leg metal layer.

[0201] At block 2518 , a bolometer resistive sensing material (eg, a temperature sensitive resistive material such as VOx) may be deposited and patterned to form a sensor layer of the bolometer bridge.

[0202] At block 2520, a second bridge dielectric material may be deposited and patterned to define a bridge region for each microbolometer formed on at least a portion of the underlying leg material.

[0203] At block 2522 , the sacrificial layer and additional sacrificial layers may be removed to release the bridge structure and the vertical leg structures such that the bridge and legs formed beneath the bridge are suspended above the substrate and the contact structure is coupled to the bridge structure through the vertical leg structures.

[0204] In traditional bolometer manufacturing methods, patterning is done along the X and Y dimensions, while material thickness is deposited as a sheet-like film in the Z dimension. The sheet-like film controls the thickness of the device in the Z dimension. Fig.26 A top view of the bolometer is shown. Fig. 27 Shown along Fig.26A cross section of a leg of line 2605. In particular, the cross section is a cut along line 2605 in the x-direction (e.g., horizontal width direction) and viewed in the y-direction (e.g., in the leg length direction). The leg includes: an insulator material 2705; a conductive layer 2710 disposed on the insulator material 2705; and an insulator material 2715 disposed on the conductive layer 2710. The insulator material 2705, the conductive layer 2710, and the insulator material 2715 are disposed one above the other along the Z dimension. It should be noted that Fig. 27 An embodiment is shown where the material deposition thickness (MDT) is similar for insulator material 2705, conductive layer 2710, and insulator material 2715. However, the MDT between these materials / layers need not be the same.

[0205] As the pixel size is reduced, the amount of area in the X and Y directions is also reduced. To increase sensitivity, the thickness of the bolometer material is also reduced. This reduction in the thickness of the bolometer material is associated with a corresponding reduction in the amount of structural support built into the bolometer. To increase the rigidity of this reduced size bolometer, a vertical member can be added to the bolometer structure.

[0206] Fig.28 The stiffness provided by the vertical components is shown, for example. The total mass of this flat piece of metal is M. If this flat piece of metal is supported at both ends, this flat piece of metal can support a certain amount of weight W1. If this piece of metal with a total mass M is formed into an I-beam structure or other similar structure with vertical sections, then this piece of metal can support a weight W2 that is greater than the weight W1.

[0207] In the case of smaller pixels, the thickness of the material is reduced to support the desired performance. As the material becomes thinner, the stiffness decreases until the legs of the bolometer cannot support the mass of the bolometer without introducing vertical members in the legs to add stiffness / support the pixel. In the design of the vertical legs, the thickness of the material may be controlled more than the Z dimension. The variation in the height of the vertical members in the legs can affect the thermal and electrical properties of the legs. This effect on the thermal and electrical properties may have an impact on the performance of the bolometer.

[0208] Fig.29 A top view of a microbolometer array with vertical legs is shown according to one embodiment. Fig. 30A Shown along Fig.29A cross section of a leg of line 2905. In particular, the cross section is a cut along line 2905 in the x-direction (e.g., horizontal width direction) and viewed in the y-direction (e.g., in the leg length direction). The leg has a Z-shaped cross section (e.g., also considered an S-shaped cross section). The leg includes an insulator material 3005, a conductive layer 3010 disposed on the insulator material 3005, and an insulator material 3015 disposed on the conductive layer 3010. The insulator material 3005, the conductive layer 3010, and the insulator material 3015 are disposed one after another along the Z-shaped dimension. The z-shaped cross section provides a path from the bridge to the contact. The contact can be a contact of the substrate. Portions 2910 and 2915 of the thermal radiation meter show the transition region from the corresponding leg to the corresponding contact. It should be noted that Fig. 30A An embodiment is shown where the MDTs of insulator material 3005, conductive layer 3010, and insulator material 3015 are approximately the same. However, the MDTs between these materials / layers are not necessarily the same.

[0209] like Fig. 30A As shown, the serpentine cross-section of the leg has: a first section (e.g., a left section or a lower section); a second section (e.g., a right section or an upper section) substantially parallel to the first section; and a third section (e.g., a middle section) connecting the first section and the second section. In order to connect the bridge to the contact of the substrate, the leg can extend between the bridge and the contact along a first direction (e.g., an X direction) and / or a second direction (e.g., a Y direction) substantially parallel to the plane of the substrate. The serpentine cross-section (e.g., an s-shape or a z-shape) is maintained along the x- and / or y-directions. In this regard, the first section and the second section extend along the first direction and / or the second direction, substantially parallel to the plane. The third section connects the first section and the second section in a third direction (e.g., a Z direction) substantially perpendicular to the plane.

[0210] about Fig. 30AIn the particular cross section of the leg shown, the leg has a segment 3020 associated with a first section, a segment 3025 associated with a second section, and a segment 3030 associated with a third section. The segment 3030 is adjacent to the segment 3020 and the segment 3025. Each of the segments 3020, 3025, and 3030 has: a first dimension (e.g., width) extending in an X direction substantially parallel to a plane of the substrate surface; and a second dimension (e.g., height) extending in a Z direction substantially perpendicular to the plane. For the segments 3020 and 3025, the first dimension is greater than the second dimension. For the segment 3030, the first dimension is less than the second dimension. Each of the segments 3020, 3025, and 3030 has: a corresponding portion of the insulator material 3005, a corresponding portion of the conductive layer 3010; and a corresponding portion of the insulator material 3015. The insulator material 3005 is formed on a first sidewall of the conductive layer 3010 and a first side of the conductive layer 3010. Insulator material 3015 is formed on the second sidewall of conductive layer 3010 and the second side of conductive layer 3010. The first sidewall is opposite to the second sidewall. The first sidewall is substantially perpendicular to the first side. The first side is opposite to the second side. In some aspects, if the angle between two segments / regions / portions is within ±10° of 90°, they can be referred to as being substantially perpendicular. In some aspects, if the angle between two segments / regions / portions is within ±10° of 0°, then two segments / regions / portions can be referred to as being substantially parallel.

[0211] Various methods can be used to define the vertical portion of the legs. Each method is associated with complexity, variability, and materials (e.g., affecting performance). The deposited film can have an ideal uniformity across the entire wafer and have small variations in different continuity (e.g., wafer to wafer). In this way, the deposited film can be used to control the vertical portion. In one aspect, the thermal radiation meter can include a deposited film of a conductive material (such as a metal) and a deposited film of a non-conductive material (such as an insulator). Dry etching associated with traditional CMOS processing can be used to selectively remove one type of film from another (e.g., metal can be removed where there is no insulator protection). For example, an insulator is a barrier to metal etching, and a metal is a barrier to insulator etching. After etching, the legs may have insulator and / or metal remaining on the legs, which will affect the performance of the thermal radiation meter.

[0212] In some aspects, the Z-height of the legs can be reduced (e.g., relative to Fig. 30A ) while creating additional rigidity for the bolometer. Fig. 30B According to one embodiment, a Fig. 30A The smaller the outrigger height, the smaller the cross-section of the outrigger. Fig. 30BThe leg of has a segment 3035 (e.g., associated with the first section), a segment 3040 (e.g., associated with the second section), and a segment 3045 (e.g., associated with the third section). In one aspect, the segments 3035, 3040, and 3045 can be considered to correspond to Fig. 30A Leg segments 3020, 3025 and 3030. In some cases, given that the Z dimension exceeds a desired threshold to satisfy the minimum stiffness of the bolometer, depending on the specific implementation, it may be more meaningful to control the height of the entire wafer rather than the actual average of the Z dimension.

[0213] Although in Fig. 30A and 30B In the embodiment, the third section is substantially perpendicular to the first section and the second section, but in various embodiments, the third section is at an angle (e.g., nominally at an angle) relative to the first and second sections. In this regard, such a third section is similar to Fig. 30A and 30B The third section shown in FIG. 1 is inclined in comparison. Fig.31 An example cross section of a leg 3100 having an inclined portion according to one or more embodiments is shown. The cross section of the leg 3100 has a first section, a second section substantially parallel to the first section, and a third section that is inclined and connected to the first and second sections. Fig.31 For the particular cross-section of the leg 3100 shown, the leg 3100 has a segment 3105 associated with the first section, a segment 3110 associated with the second section, and a segment 3115 associated with the third section. The segment 3115 is at about 45 degrees relative to the horizontal axis (e.g., left-right direction) associated with the segments 3105 and 3110. In other embodiments of the leg structure, the middle section can be Figures 30A-30B (e.g., substantially perpendicular to its adjacent sections) and Fig.31 The angle shown in FIG. 31 is different (eg, about 45° relative to its adjacent sections). By way of non-limiting example, the intermediate sections may be angled about 30° to 60° relative to a horizontal axis associated with segments 3105 and / or 3110.

[0214] The leg 3100 has a dielectric layer 3120, a dielectric layer 3125 disposed on the dielectric layer 3120, a leg metal layer 3130 disposed on the dielectric layer 3125, and a dielectric layer 3135 disposed on the leg metal layer 3130. In this regard, the leg metal layer 3130 is surrounded by the dielectric layers 3135 and 3125 on at least two opposing sides. The leg 3100 has a tail 3140 of the dielectric layer 3120. There is a gap 3145 between the tail 3140 and one side of the dielectric layer 3125 so that the tail 3140 faces the dielectric layer 3125. In one aspect, the tail 3140 can be formed as a result of an etching operation performed to form the leg 3100.

[0215] In one or more embodiments, the leg manufacturing process may include or may be based on directed self-assembly (DSA) (e.g., polymer-based), oxide patterning, and / or other. Each process has several variations. Different processes may be associated with different process complexities, exposure resolutions, overlays, and the like. In some aspects, each process has variations in the order of device features. For example, legs, contacts, and bridges may be processed in any order. Each device feature order is associated with its set of trade-offs (e.g., complexity, cost, etc.). In some aspects, various paths / options that facilitate vertical leg manufacturing may allow the legs to be processed separately from the bridge. In some cases, the leg material may be independent of (e.g., completely independent of) the bridge. In some cases, some of the leg material is on the bridge (e.g., in contact with the bridge). Higher independence between the legs and the bridge is typically associated with more complex processes.

[0216] As an example, Fig.32 A top view of a bolometer with bridge 3320, vertical legs, and contacts 3315 and 3350 is shown, wherein the bolometer is fabricated using an oxide method according to one embodiment. In some cases, the oxide method may be associated with lower process complexity than the DSA method. The oxide method may facilitate model associativity / feedback. Fig.33 Shown along Fig.32 A cross section of a leg of line 3205. The bolometer includes: a substrate 3305; a pad 3310; a contact 3315 (e.g., a basket contact, a stud contact); a bridge 3320; and portions 3325, 3330, 3335, 3340, and 3345 of the leg; and a contact 3350. Portions 3325 and 3330 provide a path between contact 3315 and bridge 3320, and portion 3330 of the leg transitions to bridge 3320. Portions 3335, 3340, and 3345 provide a path between contact 3350 and bridge 3320. Portion 3335 transitions to bridge 3320.

[0217] As another example, Fig.34 A top view of a bolometer having a bridge 3520, vertical legs, and contacts 3515 and 3560 is shown, wherein the bolometer is fabricated using a DSA method according to one embodiment. Fig.35 The legs according to one embodiment are shown along Fig.343405. The bolometer includes substrate 3505, pad 3510, contact 3515 (e.g., basket contact), bridge 3520, leg portions 3525, 3530, 3535, 3540, 3545, 3550, and 3555, and contact 3560. Portions 3525 and 3530 provide a path between contact 3515 and bridge 3520, and leg portion 3530 transitions to bridge 3320. Portions 3535, 3540, 3545, 3550, and 3555 provide a path between contact 3560 and bridge 3520. Portion 3535 transitions to bridge 3520. Fig.35 An enlarged view of a portion of the leg is shown in FIG. The leg includes a vertical stacked arrangement of SiO2, leg metal, and Si. A portion of silicon dioxide is arranged on the metal leg. A portion of SiO2 is located below the leg metal and Si. These materials are provided by way of non-limiting example.

[0218] Figures 36A to 36N A cross-sectional side view is shown in connection with an example process for forming a bolometer according to one embodiment. Fig.37 According to one embodiment, Fig.36N The cross-sectional side view corresponds to the top view.

[0219] exist Fig.36A In the embodiment, a readout circuit wafer 3600 (e.g., an ROIC wafer) is provided. The readout circuit wafer 3600 includes a substrate 3601, a glass layer 3602, and a metal layer 3603. The cover glass layer 3602 is disposed on the substrate 3601. The metal layer 3603 extends through the cover glass layer 3602. A thermal radiation meter process is performed on the readout circuit wafer 3600 to form a thermal radiation meter connected to the readout circuit wafer 3600. Figures 36B to 36C , describes an embodiment of a thermal radiation meter process. Fig.36B In FIG. 3 , pad 3604 is arranged on readout circuit wafer 3600. Pad 3604 may form part of one or more metal layers. Fig.36C , a release layer 3606 (e.g., also referred to as a sacrificial layer) is disposed on the cover glass layer 3602 and the pad 3604, and a protective layer 3608 is disposed on the release layer 3606. The release layer 3606 may be a polyimide coating. The protective layer 3608 may be deposited as a thin film over the release layer 3606.

[0220] exist Fig.36D, a metal layer 3612 is disposed on the protective layer 3608, and a dielectric layer 3614 is disposed on the metal layer 3612. The metal layer 3612 can be a titanium layer. In some cases, the metal layer 3612 can form or can be referred to as an absorption layer. In these cases, the absorption layer can be formed of, for example, titanium. The metal layer 3612 can be used as an etch stop layer for subsequent etching operations (e.g., allowing the oxide layer(s) to be etched until the metal layer 3612). The dielectric layer 3614 can be formed of Si3N4. The metal layer 3612 and the dielectric layer 3614 can be deposited as thin film films.

[0221] exist Fig.36E In the embodiment of the present invention, the metal layer 3612 and the dielectric layer 3614 are etched. In order to facilitate the etching of the metal layer 3612 and the dielectric layer 3614, one or more patterning operations may be performed. Generally speaking, before the etching operation, a photoresist is deposited and patterned to define the portion of the material to be etched / removed, and each etching operation may be isotropic or anisotropic. Patterning may include depositing a photoresist layer and exposing the photoresist layer to determine multiple portions of the metal layer 3612 and the dielectric layer 3614 to be etched. Etching may be performed on the metal layer 3612 and the dielectric layer 3614, and then the photoresist layer may be removed. In one aspect, a first etching operation (e.g., reactive ion etching) may be performed to etch down through the dielectric layer 3612 to the metal layer 3614. A second etching operation (e.g., a different chemical composition from the first etching operation) may be performed to etch down through the metal layer 3614 to the protective layer 3608. Block 3616 may identify portions of metal layer 3612 and dielectric layer 3614 that remain after etching. In some cases, block 3616 may represent masking materials used to facilitate patterning and etching to obtain metal layer 3612 and dielectric layer 3614, such as Fig.36E shown.

[0222] exist Fig.36F In the embodiment, a resistor layer 3622 (eg, VO x layer, TiO x The resistive layer 3622 is configured to contact the protective layer 3608, the metal layer 3612, and the dielectric layer 3614. The dielectric layer 3624 is disposed on the resistive layer 3622. The dielectric layer 3624 may be a cap layer of the resistive layer 3622. Figure 36GIn the embodiment of the present invention, the resistive layer 3622 and the dielectric layer 3624 are etched. Such etching may etch the resistive layer 3622 and the dielectric layer 3624 so that they define thermistors of the thermal bolometer to be formed. Block 3630 identifies the portion of the resistive layer 3622 and the dielectric layer 3624 that remain after etching. In some cases, block 3630 may represent a mask material used to facilitate patterning and etching to obtain the resistive layer 3622 and the dielectric layer 3624, such as Figure 36G As shown. Block 3630 can be considered as defining the sensing portion of the bridge and the non-sensing portion of the bridge. The sensing portion of the bridge has a resistive layer 3622, while the non-sensing portion of the bridge does not have a resistive layer 3622. Figure 36G , the sensing portion of the bridge is directly below block 3630 and is associated with region 3660, while the non-sensing portion of the bridge is associated with regions 3662 and 3664 adjacent to region 3660. Regions 3662 and 3664 can form a region surrounding region 3660. In some embodiments, the non-sensing portion of the bridge can have perforations defined therein to reduce the thermal mass associated with the bridge. Fig.49 , an embodiment of a bridge having perforations defined in a non-sensing portion of the bridge is described.

[0223] exist Fig.36H In the embodiment, dielectric layer 3632 is configured such that dielectric layer 3632 is in contact with protective layer 3608, metal layer 3612, dielectric layer 3614, resistive layer 3622, and dielectric layer 3624. In some cases, dielectric layer 3632 is formed of the same material as dielectric layer 3624 and / or 3614. Fig.36I In the embodiment, the resistive layer 3622 and the dielectric layer 3624 are etched to expose the resistive layer 3622. A block 3634 identifies a portion of the resistive layer 3622 and the dielectric layer 3624 that is not removed after etching. In some cases, the block 3634 may represent a mask material used to facilitate patterning and etching to obtain the resistive layer 3622 and the dielectric layer 3624, such as Fig.36I As shown. Fig.36J In the embodiment, the leg metal layer 3636 is configured to make the leg metal layer 3636 contact the dielectric layer 3632, the resistor layer 3622, and the dielectric layer 3624. A portion of the leg metal layer 3636 on the resistor layer 3622 may be referred to as a resistor layer contact (e.g., a thermistor contact). The leg metal layer 3636 may be made of, for example, titanium, tungsten, copper, or other metals. Figure 36K , dielectric layer 3638 is disposed on leg metal layer 3636. In one aspect, dielectric layer 3638 can be disposed using a very thin sheet of film, such as atomic layer deposition (ALD).

[0224] exist Figure 36L In the embodiment of the present invention, a portion of the protective layer 3608, the dielectric layer 3632, the leg metal layer 3636, and the dielectric layer 3638 are etched. In some cases, performing the metal etch and the oxide etch may be performed alternately as appropriate to etch the layers 3632, 3636, and 3638 at a time. Block 3640 identifies the portions of the layers 3608, 3632, 3636, and 3638 that remain after etching. In some cases, block 3640 may represent a method for facilitating patterning and etching to obtain Figure 36L In one aspect, various patterning and etching operations are performed to form bridge 3644. Figure 36M 3608, 3632, 3636, and 3638 are etched. Block 3642 identifies the portions of layers 3608, 3632, 3636, and 3638 that remain after etching. In some cases, block 3642 may represent a method for facilitating patterning and etching to obtain Figure 36M Masking materials for layers 3608, 3632, 3636, and 3638 are shown in FIG. Figure 36L and 36M Helps to define Fig.36N In one aspect, Figure 36L Related to opening / cutting the bottom of the leg structure, Figure 36M Has to do with opening / cutting the top of the leg structure.

[0225] exist Fig.36N and 37 , various operations are performed to form contacts 3648 (e.g., basket contacts) between pads 3604 and vertical legs 3647. A drilling operation may be performed to open a trench (e.g., also referred to as an opening) through release layer 3606 to readout circuit wafer 3600. In some cases, the drilling operation may include an etching operation. Contacts 3648 and vertical legs 3646 together connect bridge 3644 to substrate 3601 (e.g., ROIC). Contacts 3648 may be made of, for example, aluminum. Various material deposition operations (e.g., basket metal deposition operations), patterning operations, etching operations, and / or other operations are performed to obtain Fig.36N The etching operation results in the formation of tail portions 3650 and 3652 (e.g., also referred to as residual pieces). Tail portions 3650 and 3652 are portions of protective layer 3608 that remain after etching, while portions of metal layer 3612 (previously disposed on tail portions 3650 and 3652) have been removed due to the etching operation. Fig.36N In FIG. 3 , gaps 3654 and 3656 are above tail portions 3650 and 3652, respectively. Tail portions 3650 and 3652 of protective layer 3608 face dielectric layer 3632. Fig.36N and 37 36, a sensing portion of bridge 3644 is associated with region 3666, and a non-sensing portion of bridge 3644 is associated with region 3668 surrounding region 3666. In some embodiments, bridge 3644 may include a metal layer (e.g., an absorber layer) disposed on dielectric layer 3638. A cap layer (e.g., SiO2) may be disposed on the metal layer.

[0226] Figures 38A to 38D A cross-sectional side view is shown relating to an example process of forming contacts according to one embodiment. The contacts may be used to couple a bridge to a readout circuit wafer. Figures 38A to 38D The various characteristics of Figures 36A-36N And / or corresponding features of other figures are implemented in the same or similar manner.

[0227] exist Fig.38A In one aspect, a structure having a bridge 3844 is formed. Fig.38A The structure of can be used as a starting structure before forming contacts to connect the bridge 3844 to the readout circuit chip. The readout circuit chip includes a substrate 3801, a cover glass layer 3802 and a metal layer 3803. The pad 3804 is arranged on the readout circuit chip. The structure further includes a release layer 3806 (e.g., polyimide), a protective layer 3808, a metal layer 3812 (e.g., a MUP layer formed of titanium), a dielectric layer 3614 (e.g., oxide), a resistor layer 3822 (e.g., VO x layer) and dielectric layer 3838 (e.g., a thin film). It is worth noting that this structure directly connects bridge 3844 to the readout circuit chip without using a leg structure. In one aspect, in Fig.38D In a later processing step, legs can be selectively defined for connecting the bridge 3844 to the readout circuit wafer. If a leg structure is to be formed, the metal layer 3818 can be utilized as a leg metal layer.

[0228] exist Fig.38B 38, dielectric layer 3838 is etched. Block 3846 identifies a portion of dielectric layer 3838 that is etched. In some cases, block 3846 may represent a mask material used to facilitate patterning and etching to obtain a pattern such as Fig.38B The dielectric layer 3838 is shown. Fig.38C38, release layer 3806, protective layer 3808, metal layer 3812, dielectric layer 3814, and portions of metal layer 3818 are removed to define trench 3850. Layers 3806, 3808, 3812, 3814, 3818, and 3838 may be etched using one or more etching operations. Block 3848 identifies portions of layers 3806, 3808, 3812, 3814, 3818, and 3838 that are etched. In some cases, block 3848 may represent one or more masking materials used to facilitate patterning and etching to obtain Fig.38C In one aspect, metal layer 3812 and / or metal layer 3818 can be used as a hard mask for etching release layer 3806 (e.g., polyimide etching). Fig.38D In the embodiment, a contact metal layer 3852 is arranged. The contact metal layer 3852 is arranged on at least one pad 3804 (for example, Fig.38D The left pad in the figure) is used to connect the bridge 3844 to the readout circuit chip. The contact metal layer 3852 contacts the release layer 3806, the protective layer 3808, the dielectric layer 3814, the metal layer 3812, the metal layer 3818, the dielectric layer 3838 and one of the pads 3804. Although in Figures 38A-38D In the embodiment, a basket contact is formed, but in other embodiments, a stud contact or other type of contact may be formed. Fig.38D The structure shown in the figure is subjected to additional operations (such as removing the release layer 3806) to form a thermal radiation meter. It should be noted that it is possible to select Fig.38D The structure of the invention defines legs so that the bridge 3844 is connected to the readout circuit chip by the legs. Other operational embodiments, including the formation of legs, are related to Figures 39A to 39D Description.

[0229] Figures 39A to 39D A cross-sectional side view is shown relating to an example process of forming legs after contact formation to a readout circuit wafer according to one embodiment. Fig.40 According to one embodiment, Fig.39D The cross-sectional side view corresponds to the top view. Figures 39A to 39D The various characteristics of Figures 36A-36N and / or other figures. Figures 39A to 39D The process of forming Fig.34 and 35 Thermal radiation meter.

[0230] exist Fig.39AIn the embodiment, a structure having a bridge 3944 and a contact metal layer 3922 for connecting the bridge 3944 to the readout circuit chip is formed. In one aspect, Fig.39A The structure of can be used as a starting structure before forming the legs for connecting the bridge 3944 to the readout circuit chip. The readout circuit chip includes a substrate 3901, a cover glass layer 3902, and a metal layer 3903. The pad 3904 is arranged on the readout circuit chip. The structure further includes a release layer 3906 (e.g., polyimide), a protective layer 3908 (e.g., a poly cap layer), a metal layer 3910 (e.g., formed of titanium), a dielectric layer 3912 (e.g., a nitride (such as Si3N4) or an oxide (such as SiO2)), a resistor layer 3914 (e.g., VO x ), a leg metal layer 3916, a dielectric layer 3918 (such as a thin film layer formed of SiO2 or Si3N4), and a semiconductor layer 3920. Fig.39B , the contact metal layer 3922 is etched. Block 3924 identifies a portion of the contact metal layer 3922 that remains after etching. In some cases, block 3924 may represent a mask material used to facilitate patterning and etching to obtain Fig.39B The contact metal layer 3922 is shown in FIG.

[0231] exist Fig.39C In the embodiment, a portion of each of dielectric layer 3918, leg metal layer 3916, protective layer 3908, and release layer 3906 is etched to define trench 3926. Block 3928 identifies Fig.39C The portion of the structure remaining after etching. In some cases, block 3928 may represent a method for facilitating patterning and etching to obtain Fig.39C The mask material of the structure shown. Fig.39D and 40 , dielectric layer 3918 and leg metal layer 3916 are etched to expose semiconductor layer 3920, and release layer 3906 is removed. Thus, legs 3931, 3932, and 3930 are formed. Legs 3931 and 3932 are associated with the current pixel (e.g., bridge 3944). Leg 3930 may be associated with the next pixel.

[0232] Fig.39E It is shown in Fig.39D An enlarged view of a portion 3934 of the structure. In particular, the portion 3934 is a portion of a leg of the structure. It should be noted that Fig.39EThe materials identified in are provided by way of non-limiting example. The leg includes a vertically stacked arrangement of a semiconductor layer 3920 (e.g., Si, polystyrene), a leg metal layer 3916, and a dielectric layer 3918 (e.g., SiO2). The layers 3920, 3916, and 3918 are arranged on the metal layer 3910. The metal layer 3910 is arranged on the protective layer 3908.

[0233] Figures 41A to 41T A cross-sectional side view is shown relating to an example process of forming a bolometer according to one embodiment. Fig.42 According to one embodiment, Figure 41T The cross-sectional side view corresponds to the top view. Figures 41A to 41T The various characteristics of Figures 36A-36N And / or corresponding features of other figures are implemented in the same or similar manner.

[0234] exist Fig.41A In the embodiment, a readout circuit wafer 4100 (eg, ROIC wafer) is provided. The readout circuit wafer 4100 includes a substrate 4101, a cover glass layer 4102, and a metal layer 4103. A thermal radiation meter process is performed on the readout circuit wafer 4100 to form a thermal radiation meter connected to the readout circuit wafer 4100. Figures 41B to 41T , describes an embodiment of a thermal radiation meter process. Fig.41B In FIG. 4 , pads 4104 are arranged on the readout circuit wafer 4100. Pads 4104 may form part of one or more metal layers. Fig.41C In the embodiment, release layer 4106 is disposed on dielectric layer 4102 and pad 4104, and protective layer 4108 is disposed on release layer 4106. In some aspects, one or more alignment marks can be etched in protective layer 4108 (e.g., to facilitate alignment of a thermal radiometer process using one or more masks). Fig.41D In the embodiment, a metal layer 4112 (eg, a metal absorption layer) is disposed on the protective layer 4108, and a dielectric layer 4114 (eg, Si3N4 / SiO2) is disposed on the metal layer 4112. Fig.41E In the embodiment, protective layer 4108, metal layer 4112, and dielectric layer 4114 are etched. Patterning may include depositing a photoresist layer and appropriately exposing the photoresist layer to define portions of protective layer 4108, metal layer 4112, and dielectric layer 4114 to be etched. Block 4116 may identify portions of layers 4108, 4112, and 4114 that remain after etching. In some cases, such as Fig.41E As shown, block 4116 may represent a mask material used to facilitate patterning and etching to obtain layers 4108 , 4112 , and 4114 .

[0235] exist Fig.41FIn the embodiment of the present invention, a dielectric layer 4118 (e.g., a thin film oxide layer) and a metal layer 4120 are arranged, and the metal layer 4120 is etched. Block 4121 can identify the multiple portions of the metal layer 4120 that remain after etching. In some cases, block 4121 can represent a mask material used to facilitate patterning and etching to obtain the metal layer 4120, such as Fig.41F As shown. Figure 41G In the embodiment, a dielectric layer 4122 (eg, a thin film oxide layer), a resistor layer 4124 (eg, a VO x The dielectric layer 4122 is in contact with the dielectric layer 4118, the metal layer 4120 and the resistor layer 4124. The dielectric layer 4126 is in contact with the resistor layer 4124. Fig.41H In the embodiment of the present invention, the resistive layer 4124 and the dielectric layer 4126 are etched. Such etching can help define the bridge portion of the thermal radiation meter to be formed. Block 4128 can identify the various portions of the resistive layer 4124 and the dielectric layer 4126 that remain after etching. In some cases, block 4128 can represent a mask material used to facilitate patterning and etching to obtain the resistive layer 4124 and the dielectric layer 4126, such as Fig.41H Block 4128 can be considered as defining the sensing portion of the bridge and the non-sensing portion of the bridge. Fig.41I 4106, 4118, and 4122 to form trenches 4132 down to the readout circuit wafer 4100. In one aspect, the process of defining trenches 4132 (and, in some cases, trenches associated with other pixels of the thermal radiation meter) can be referred to as a mesh pattern. Block 4130 can identify portions of layers 4122, 4118, and 4106 to be removed to form trenches 4132.

[0236] exist Fig.41J In the embodiment, a contact metal layer 4134 is arranged. The contact metal layer 4434 is arranged on at least one pad 4104 (eg, Fig.41J 4104) to connect the bridge portion of the thermal radiation meter to the readout circuit wafer 4100. The contact metal layer 4134 contacts the release layer 4106, the dielectric layer 4118, the dielectric layer 4122 and the at least one pad 4104. The contact metal layer 4134 is used to form a contact basket. Figure 41K , the contact metal layer 4134 is etched to expose the dielectric layers 4126 and 4122. Block 4136 may identify a portion of the contact metal layer 4134 that is removed by etching. In some cases, block 4136 may represent a mask material used to facilitate patterning and etching to obtain the contact metal layer 4134, such as Figure 41K As shown. Figure 41LIn the case of a dielectric layer 4138, a dielectric layer 4138 is arranged. Figure 41M , dielectric layer 4138 is etched. Block 4140 may identify a portion of dielectric layer 4138 that remains after etching. In some cases, block 4140 may represent a mask material used to facilitate patterning and etching to obtain dielectric layer 4138, such as Figure 41M As shown. Figure 41N , the contact metal layer 4134 is etched. Block 4142 may identify a portion of the contact metal layer 4134 that remains after etching. In some cases, block 4142 may represent a mask material used to facilitate patterning and etching to obtain Figure 41N Contact metal layer 4134 is shown.

[0237] exist Fig.41O In the embodiment of the present invention, dielectric layer 4138, dielectric layer 4126, and resistive layer 4124 are etched to expose resistive layer 4124. Block 4144 may identify portions of layers 4138, 4126, and 4124 that are removed after etching. In some cases, block 4144 may represent a method for facilitating patterning and etching to obtain Fig.41O The masking materials of layers 4138, 4126 and 4124 are shown in FIG. Fig.41P In the embodiment, a leg metal layer 4146 is arranged. Figure 41Q In the embodiment of the present invention, the leg metal layer 4146 is etched. Block 4148 can identify the portions of the leg metal layer 4146 that remain after etching. In some cases, block 4148 can represent a method for facilitating patterning and etching to obtain Figure 41Q The mask material of the leg metal layer 4146 is shown in FIG. Figure 41R In the embodiment, a dielectric layer 4150 (eg, a thin film layer) is arranged.

[0238] exist Fig.41S 4150, portions of dielectric layer 4112, dielectric layer 4114, dielectric layer 4118, dielectric layer 4122, metal layer 4120, leg metal layer 4146, and dielectric layer 4150 are removed to form bridge 4153. Block 4152 may identify portions of layers 4112, 4114, 4118, 4122, 4120, 4146, and 4150 that remain after etching. In some cases, block 4152 may represent masking material used to facilitate patterning and etching to obtain layers 4112, 4114, 4118, 4122, 4120, 4146, and 4150, such as Fig.41S As shown. Figure 41T and 42 In the process, one or more patterning operations and etching operations are performed, and the release layer 4106 is removed to form Figure 41TThe bolometer includes a bridge 4153 and legs 4160 and 4161. The etching operation results in the formation of tails 4154, 4156, and 4158. The etching operation results in the formation of tails 4154, 4156, and 4158 and gaps 4162, 4164, and 4166 above the tails 4154, 4156, and 4158, respectively. Figure 41T and 42 41, a sensing portion of the bridge 4153 is associated with the region 4170, and a non-sensing portion of the bridge 4153 is associated with the region 4172 surrounding the region 4170. In some embodiments, the bridge 4153 can include a metal layer (e.g., an absorption layer) disposed on the dielectric layer 4126. A cap layer can be disposed on the metal layer.

[0239] Fig.43A and 43B A view associated with a bolometer 4300 having a bridge 4305, vertical legs 4308 and 4310, and contacts 4315 and 4320 is shown according to one embodiment. Fig.43A is a perspective view of the thermal radiation meter 4300. Fig.43B A cross section of the bolometer 4300 along line 4325 is shown. In this regard, the cross section shows a portion 4330 of the bolometer 4300 along line 4325. In some embodiments, the bolometer 4300 can be formed using the same or similar techniques as those provided herein. Fig.43B As shown, the thermal radiation meter 4300 includes a dielectric layer 4335 (eg, an insulator), a metal layer 4340 (eg, titanium), a dielectric layer 4345 (eg, an insulator), a resistor layer 4350 (eg, VO x ), leg metal layer 4355 (e.g., titanium, copper), dielectric layer 4360 (e.g., a thin insulator / oxide layer formed of Si3N4), dielectric layer 4365 (e.g., Si3N4), and dielectric layer 4370 (e.g., SiO2). Dielectric layer 4335 may be referred to as a protective layer.

[0240] The metal layer 4340 is disposed on the dielectric layer 4335. The dielectric layer 4345 is disposed on the metal layer 4340. The resistance layer 4350 is disposed on the dielectric layer 4345. The dielectric layer 4370 is disposed on the resistance layer 4350. The leg metal layer 4355 is disposed on the resistance layer 4350. The dielectric layer 4360 is disposed on the leg metal layer 4355. The dielectric layer 4370 contacts the leg metal layer 4355 and the resistance layer 4350. The contact 4315 includes a basket filling layer 4375, a leg metal layer 4355, a dielectric layer 4365, a dielectric layer 4345, a cap layer 4335, and a leg metal layer 4380. Contact 4320 includes basket fill layer 4385, metal layer 4355, dielectric layer 4365, dielectric layer 4345, cap layer 4335, and leg metal layer 4390. Basket fill layers 4375 and 4385 may be made of, for example, aluminum. Leg metal layers 4380 and 4390 may be made of, for example, titanium, tungsten, copper, or other metals. Dielectric layers 4365 and 4345 may serve as passivation layers for contacts 4315 and 4320. Although Fig.43A Contacts 4315 and 4320 are shown as basket-shaped contacts, but in other embodiments, contacts 4315 and / or 4320 may be implemented using contacts of different shapes and / or different types of contacts (such as stud contacts).

[0241] In some aspects, such as Fig.43B As shown, the etching operation performed to obtain the thermal bolometer 4300 forms tail portions 4391 and 4393 of the dielectric layer 4335. In this regard, the tail portions 4391 and 4393 still exist after etching, while portions of the metal layer 4340 (previously disposed on the tail portions 4391 and 4393 before being etched) have been removed to form voids 4392 and 4394 above the tail portions 4391 and 4393.

[0242] The resistive layer 4350 is coupled to the contacts 4315 and 4320 through the vertical legs 4308 and 4310. In this regard, the leg metal layer 4355 of the vertical legs 4308 and 4310 is in contact with the resistive layer 4350. By way of non-limiting example, the resistive layer 4350 may include VO x 、TiO x Or amorphous silicon. Vertical legs 4308 and 4310 are connected to bridge 4305 and contacts 4315 and 4320. Leg metal layers 4380 and 4390 of contacts 4315 and 4320 are connected to a substrate (e.g., ROIC), respectively. Thus, bridge 4305 is coupled to the substrate via vertical legs 4308 and 4310 and contacts 4315 and 4320. Contacts 4315 and 4320 may contact (e.g., physically contact) a metal layer of the substrate. In some cases, the substrate may have a cover glass layer formed thereon.

[0243] As a non-limiting example, the thicknesses of the cap layer 4335, the metal layer 4340, the dielectric layer 4345, the resistor layer 4350, the metal layer 4355, the dielectric layer 4360, the dielectric layer 4370, and the dielectric layer 4365 are 250 angstroms, 300 angstroms, 750 angstroms, 600 angstroms, 300 angstroms, 300 angstroms, 300 angstroms, and 500 angstroms, respectively. The distance D refers to the distance between the bottom surface of the cap layer 4335 and the bottom surface of the leg metal layer 4390. A non-limiting example of the distance D can be about 1.5 microns. As a non-limiting example, the width W and height H of the vertical legs can be about 0.24 microns and 0.25 microns, respectively.

[0244] Figures 44A to 44E Various views are shown relating to a bolometer 4400 having a bridge 4405, vertical legs 4408 and 4410, and contacts 4415 and 4420, according to one embodiment. Fig.44A A perspective view of a thermal radiation meter 4400 is shown. Fig.44B An enlarged view of a portion 4424 of the bolometer 4400 is shown. The portion 4424 shows the connection of the vertical legs 4410 to the bridge 4405. Fig.44C A side view cross section of thermal radiation meter 4400 along line 4425 is shown. Fig.44D Shows Fig.44C An enlarged view of a portion 4404 of the side cross section. Fig.44E yes Fig.44C 4406. The bolometer 4400 includes a cap layer 4435.

[0245] The thermal radiation meter 4400 includes a cap layer 4435 (e.g., a polyester cap), a metal layer 4440 (e.g., titanium), a dielectric layer 4445 (e.g., Si3N4), a dielectric layer 4460, a dielectric layer 4461, a dielectric layer 4462, a resistor layer 4450 (e.g., VO x ), a leg metal layer 4455 (e.g., titanium), a dielectric layer 4465 (e.g., Si3N4), and a dielectric layer 4470 (e.g., VO formed of SiO2 x Cap). In one aspect, dielectric layers 4460, 4461, 4462, and 4460 can be thin dielectric layers, such as a thin layer of Si3N4. Contact 4415 includes basket liner layer 4480. Contact 4420 includes basket liner layer 4490.

[0246] At portion 4404 of bridge 4405, Fig.44C and 44DThe cross-sectional view of FIG. 44 shows that the metal layer 4440 is arranged on the cap layer 4435. The dielectric layer 4445 is arranged on the metal layer 4440. The dielectric layer 4461 is arranged on the dielectric layer 4445. The dielectric layer 4462 is arranged on the dielectric layer 4461. The resistance layer 4450 is arranged on the dielectric layer 4462. The dielectric layer 4470 is arranged on the resistance layer 4450. The dielectric layer 4465 is arranged on the dielectric layer 4470 and the dielectric layer 4462. The dielectric layer 4460 is arranged on the dielectric layer 4465.

[0247] At portion 4406 of vertical leg 4410, Fig.44C and 44E (and further described below Fig.45F ) shows that dielectric layer 4462 is disposed on dielectric layer 4461. Leg metal layer 4455 is disposed on dielectric layer 4462 and is surrounded by dielectric layers 4460 and 4462 on at least two opposing sides. Vertical leg 4410 has tail 4464 of dielectric layer 4461. There is a gap 4492 between tail 4464 and one side of dielectric layer 4462, so that tail 4464 faces dielectric layer 4462. In some aspects, such as, for example Fig.44A and 44B As shown, ridges or steps can be formed in dielectric layer 4460, which are formed by the connection of leg 4410 to bridge 4405, which adds structural support. In this regard, various steps can be included in bridge 4405 to improve the structural integrity of bridge 4405.

[0248] For example Fig.44E As shown, vertical leg 4410 has an s-shaped (e.g., also considered a z-shaped or serpentine) cross-section formed by leg metal layer 4455 surrounded by dielectric layers 4460 and 4462 (e.g., passivated), with tail 4464 forming a residual piece of dielectric layer 4461. In this regard, vertical leg 4410 has a bottom horizontal segment 4468, a top horizontal segment 4469, and a middle vertical segment 4466 between bottom horizontal segment 4468 and top horizontal segment 4469 (e.g., adjacent to the bottom horizontal segment), which together define an s-shaped cross-section. Bottom horizontal segment 4468 is substantially perpendicular to middle vertical segment 4466 and substantially parallel to top horizontal segment 4469. Top horizontal segment 4469 is substantially perpendicular to middle vertical segment 4466. In certain aspects, two segments / portions may be referred to as being substantially perpendicular if the angle between the two segments / portions is within ±10° of 90°. In certain aspects, two segments / portions may be referred to as being substantially parallel if the angle between the two segments / portions is within ±10° of 0°.

[0249] Dielectric layer 4460 is formed on a first sidewall of leg metal layer 4455 and a first side of leg metal layer 4455. Dielectric layer 4462 is formed on a second sidewall of leg metal layer 4455 and a second side of leg metal layer 4455. The first sidewall is opposite to the second sidewall, and the first side is opposite to the second side. The first sidewall is substantially perpendicular to the first side. The second sidewall is substantially perpendicular to the second side. Vertical leg 4406 (e.g., each segment thereof) has: a first dimension extending in a first direction, the first direction being substantially perpendicular to a plane defined by a surface of a substrate (e.g., substrate 4101); and a second dimension extending in a second direction, the second direction being substantially parallel to the plane. In some aspects, at least as Fig.44C and 44E As shown, in the middle vertical segment 4466, the first dimension of the vertical leg 4406 (e.g., the dimension in the z-direction) is greater than the second dimension of the vertical leg 4406 (e.g., the dimension in the x-direction or the y-direction). In this regard, in the middle vertical segment 4465, the first dimension of the leg metal layer 4455 is greater than the second dimension of the leg metal layer 4455, the first dimension of the dielectric layer 4460 is greater than the second dimension of the dielectric layer 4460, and the first dimension of the dielectric layer 4462 is greater than the second dimension of the dielectric layer 4462. In the bottom horizontal segment 4468 and the top horizontal segment 4469, the first dimension of the vertical leg 4406 is less than the second dimension of the vertical leg 4406. In this regard, the first dimensions of the leg metal layer 4455, the dielectric layer 4460, and the dielectric layer 4462 are less than the second dimensions of the leg metal layer 4455, the dielectric layer 4460, and the dielectric layer 4462, respectively.

[0250] Figures 45A to 45F A cross-sectional side view is shown associated with an example process of forming a bolometer 4400 according to one embodiment. Figures 46A to 46F A top view is shown in relation to an example process according to one embodiment. A cross-sectional side view is taken along Fig.44A Line 4425. Fig.45A In the embodiment, a release layer 4505 (eg, polyimide) is deposited (eg, on a substrate ( Fig.45A (not shown)). A cap layer 4435 is deposited on the release layer 4505, a metal layer 4440 is deposited on the cap layer 4435, and a dielectric layer 4445 is deposited on the metal layer 4440. Fig.45B and 46A In the embodiment, a dielectric layer 4461 is disposed (e.g., using a thin film deposition). A metal layer 4542 (e.g., a sacrificial metal layer) is disposed on the dielectric layer 4461 and etched. Fig.45C and 46B4, dielectric layer 4462 is disposed (eg, using thin film deposition) on dielectric layer 4461 and metal layer 4542. Resistive layer 4450 is deposited on dielectric layer 4462 and patterned / etched. Dielectric layer 4470 is disposed on resistive layer 4450. Fig.47A and 47B Shows Fig.45C An enlarged view of portions 4502 and 4504.

[0251] exist Fig.46C In , grooves 4615 and 4620 are formed for forming contacts 4415 and 4420, respectively. Metal layer 4605 is deposited and then etched away from the portion forming bridge 4405 of thermal radiation meter 4400. Fig.45D and 46D In, basket liner layers 4480 and 4490 are arranged, and dielectric layer 4465 is deposited and etched. The basket is patterned and portions 4620 and 4625 are etched to form contacts for resistive layer 4450. Fig.45E and 46E In the embodiment of the present invention, the leg metal layer 4455 is deposited and partially etched away. In this regard, a portion of the leg metal layer 4455 remains on the portions 4620 and 4625 of the resistor layer 4450. The leg metal layer 4455 is disposed on the basket liner layers 4480 and 4490. Fig.45F and 46F In the embodiment, dielectric layer 4460 is deposited, leg metal layer 4455 is cut to form vertical legs 4408 and 4410, metal layer 4542 is removed, and release layer 4505 is removed to release bridge 4405 and vertical legs 4408 and 4410. It should be noted that Fig.45F Shows Fig.44C It is further noted that Fig.46F Shown with Fig.44A Same stereogram.

[0252] In some embodiments, the bolometer may have a thermal conductivity that is not provided by the bolometer including a resistive layer (eg, VO x) defined by multiple portions of the thermal radiation meter. In some aspects, the perforations defined by the thermal radiation meter are along the same plane / layer of the legs and bridge of the thermal radiation meter. The size of the perforations can appropriately reduce the thermal mass associated with the thermal radiation meter while maintaining the infrared sensing capabilities and structural integrity of the thermal radiation meter. In this regard, the perforations can reduce the thermal mass while allowing the thermal radiation meter to capture incident photons with wavelength components within a desired wavelength range. The reduced thermal mass can enable faster cooling and heating of the thermal radiation meter. In some aspects, such a thermal radiation meter may include the vertical legs described herein for connecting the bridge and readout circuitry (e.g., ROIC) of the thermal radiation meter. In other aspects, such a thermal radiation meter does not utilize vertical legs to connect the bridge and readout circuitry of the thermal radiation meter.

[0253] Fig.48 is a flow chart of illustrative operations that may be used to form a thermal radiation meter according to one embodiment. In some embodiments, a thermal radiation meter may be related to, for example, Fig.29 , 32 , 34, 36N, 37, 39D, 40, 41T, 42, 43A, 43B and 44A-44E. As a non-limiting example, the flowchart is about Figures 41A to 41T One or more of the descriptions.

[0254] At block 4805, a bridge structure is formed on the sacrificial layer. Fig.41S and 41T , the bridge structure may include a bridge 4153, and the sacrificial layer may include a release layer 4106. The bridge 4153 includes a protective layer 4108, a metal layer 4112 (e.g., a metal absorption layer), a dielectric layer 4114, a dielectric layer 4118 (e.g., a thin film oxide layer), a dielectric layer 4122 (e.g., a thin film oxide layer), a resistor layer 4124, and a dielectric layer 4150 (e.g., a thin film layer). In some portions of the bridge 4153, a leg metal layer 4146 is arranged on the resistor layer 4124 (e.g., in order to facilitate connecting the bridge 4153 to the substrate 4101 through the leg 4160). In some portions of the bridge 4154, a cap layer (e.g., VO x cap).

[0255] At block 4810, an opening is formed in a sacrificial layer. Fig.41I , the opening may be trench 4132. At block 4815, a contact metal layer is disposed on the sidewalls of the opening. Figures 41J to 41N , the contact metal layer may be the contact metal layer 4134. Figures 41J to 41N As shown, a layer of contact metal material may be deposited and suitably etched.

[0256] At block 4820, a leg structure is formed. The leg structure couples the bridge structure to the contact metal layer. For example, referring to Figure 41T , the leg structure may include a leg 4160 that couples the bridge 4153 to the contact metal layer 4134. The leg 4160 includes a dielectric layer 4118, a dielectric layer 4122, a leg metal layer 4146, and a dielectric layer 4150. Different portions of the leg 4160 may have a Z-shaped cross-section (e.g., Figure 41T rightmost portion of the middle leg 4160) or an S-shaped section (e.g., Figure 41T The leg 4160 has tail portions 4154, 4156 and 4158 and gaps 4162, 4164 and 4166 above the tail portions 4154, 4156 and 4158, respectively.

[0257] At block 4825, the sacrificial layer is removed to release the bridge structure and the leg structure. After removing the sacrificial layer, the bridge structure and the leg structure are suspended above the substrate 4101.

[0258] It should be pointed out that Fig.48 The flowchart of FIG. 48 shows the formation of a thermal radiation meter. In some cases, one or more additional thermal radiation meters can be formed together with the formation of the thermal radiation meter (e.g., formed simultaneously). For example, a plurality of bridge structures can be formed on the sacrificial layer at block 4805, a plurality of openings can be formed in the sacrificial layer at block 4810, and so on.

[0259] Fig.49 A perspective view of a bolometer 4900 is shown according to one embodiment. Fig.50 A top view of a thermal radiation meter 4900 is shown according to one embodiment. Dielectric layer 4906 may be a thin film layer formed of Si3N4. Thermal radiation meter 4900 includes: a bridge 4905; vertical legs 4908 and 4910 and contacts 4915 and 4920. Bridge 4905 includes a sensing portion 4906 and a remaining portion 4907 (e.g., also referred to as a non-sensing portion). Sensing portion 4906 is a portion of bridge 4905 that includes a resistive layer (e.g., VO x 4906. The remaining portion 4907 is a portion of the bridge 4805 that does not include the resistive layer. The remaining portion 4907 surrounds the sensing portion 4906. The remaining portion 4907 has perforations as defined herein, wherein perforations 4909 are labeled. Vertical legs 4908 are connected to the sensing portion 4906 of the bridge 4905 via leg / bridge contacts 5014. Vertical legs 4910 are connected to the sensing portion 4906 of the bridge 4905 via leg / bridge contacts 5013. Contacts 4915 include basket lining layer 4980. Contacts 4920 include basket lining layer 4990.

[0260] Figures 51A to 51C Other examples of thermal radiation meters according to one or more embodiments are shown. In particular, Fig.51A , 51B 51C and 51C show top views of thermal radiation meters 5100, 5130 and 5160, respectively. Fig.51A The bolometer 5100 includes a bridge 5105 having a sensing portion 5106 and a non-sensing portion 5107, vertical legs 5108 and 5110, leg / bridge contacts 5113 and 5114, and contacts 5115 and 5120. The non-sensing portion 5107 includes perforations, one of which 5109 is labeled. Fig.51B The bolometer 5130 includes a bridge 5135 having a sensing portion 5136 and a non-sensing portion 5137, vertical legs 5138 and 5140, leg / bridge contacts 5143 and 5144, and contacts 5145 and 5150. The non-sensing portion 5137 includes perforations, one of which 5139 is labeled. Fig.51C The bolometer 5160 includes a bridge 5165 having a sensing portion 5166 and a non-sensing portion 5167, vertical legs 5168 and 5170, leg / bridge contacts 5173 and 5174, and contacts 5175 and 5170. The non-sensing portion 5167 includes perforations, one of which 5169 is labeled.

[0261] like Fig.50 and 51A As shown in Figure 51C, the thermal radiation meter can have different structural features to obtain the desired performance. As non-limiting examples, such structural features include the number of bends in the legs (e.g., vertical legs), the size of the legs, the materials used to form the legs, the number of perforations in the non-sensing portion of the bridge, and the arrangement of the perforations.

[0262] Fig.52 5206 and a non-sensing portion 5207 (e.g., VO x ). Fig.53A cross-sectional side view of a portion of a thermal radiation meter having a perforation defined therein according to one embodiment is shown. The thermal radiation meter includes a bridge 5305 and a leg 5310 coupled to the bridge 5305. The bridge 5305 includes a sensing portion 5306 having a thermistor and a non-sensing portion 5307 without thermistor. The thermistor may be disposed on a first insulator. The second insulator may be disposed on the thermistor. The absorption layer may be disposed on the second insulator. The third insulator may be disposed on the metal layer. Each of the first insulator, the second insulator, or the third insulator may include one or more insulator layers. Alternatively or in addition Fig.53 In addition to the absorber layer shown, the absorber layer may be arranged between the insulator layers of the first insulator.

[0263] Perforations 5309 and 5311 are formed in the non-sensing portion 5307. Perforations 5309 and 5311 can be formed using one or more etching operations. In some aspects, each etching operation can be implemented using a different etching chemistry (e.g., depending on the material to be etched). In some embodiments, Fig.52 The thermal radiation meter may have a perforation formed in the non-sensing portion 5207 to reach Fig.53 In one case, each layer of material may be formed with the layer having perforations defined therein. For example, a first layer of material may be formed with perforations defined therein. A second layer of material may then be formed over the first layer of material, with the second layer of material having perforations defined therein that are appropriately aligned with the perforations of the first layer of material. In another case, Fig.52 The thermal radiation meter then forms perforations through all the insulators of the non-sensing portion 5207.

[0264] Fig.54 is a flow chart of illustrative operations that may be used to form a bolometer having a through hole defined therein according to one embodiment. In some embodiments, the bolometer may be related to, for example Fig.49 , 51A - Any of the thermal radiation meters described in -51C and 53.

[0265] At block 5405, a bridge structure is formed. In some embodiments, the bridge structure may be formed by performing a process similar to Fig.25 In some cases, you can perform Fig.25 Some or all of the blocks shown in may be used to form a bridge structure.

[0266] At block 5410, a leg is formed for connecting the bridge structure to the readout circuit. In some aspects, the leg is a vertical leg, as described with reference to one or more embodiments. In some cases, the vertical leg can be formed at the same time as the bridge structure is formed. In some embodiments, the vertical leg can be formed by performing a method similar to Figure 20-22 One or more of the operations provided are used to form the legs.

[0267] At block 5415, perforations are formed in the bridge structure to obtain a microbolometer bridge. The perforations can be formed using one or more etching operations. In some aspects, each etching operation can be implemented using a different etching chemistry (e.g., depending on the material to be etched). Alternatively, perforations can be formed in each layer. In this case, semiconductor processing techniques are performed to directly form the microbolometer bridge (e.g., without the need to completely form the bridge structure without perforations and then form perforations in the bridge structure). For example, a first layer of material can be formed and perforations defined therein. A second layer of material can then be formed on the first layer of material, wherein the second layer of material has perforations defined therein that are appropriately aligned with the perforations of the first layer of material.

[0268] Please note, Fig.54 One or more operations of the bridge structure may be combined, omitted, and / or performed in a different order as desired. For example, the bridge structure, the legs, and / or the perforations in the bridge structure may be formed together and / or as separate processing steps.

[0269] Figures 55A to 55D A cross-sectional side view is shown relating to an example process of forming a bolometer according to one embodiment. Fig.56 According to an embodiment, Fig.55D The cross-sectional side view corresponds to the top view. Figures 55A to 55D The various characteristics of Figures 36A-36N And / or corresponding features of other figures are implemented in the same or similar manner.

[0270] exist Fig.55A The structure includes a substrate, a cover glass layer 5602, a pad 5604, a release layer 5506, a protective layer 5508, a metal layer 5512, a dielectric layer 5514 (e.g., Si3N4 / SiO2), a metal layer 5520, a resistor layer 5524 (e.g., VO x layer), dielectric layer 5526, contact metal layer 5534 and leg metal layer 5546. The structure also includes a similar Figures 36A-36N other layers in the Fig.55A There is no clear indication. Fig.55B In, yes Fig.55A The structure is patterned and etched. Fig.55C in Fig.55B A patterning and etching operation is performed on the structure to define a through hole in the thermal bolometer bridge (eg, a non-sensing portion of the thermal bolometer bridge). Fig.55C , 55D An example perforation 5550 is shown in FIG. Fig.55D and 56 In, yes Fig.55C This operation removes the release layer and forms the tail of the dielectric layer. It should be noted that the perforations (including perforations 5550) are shown as having an octagonal shape. More generally, the perforations can be other shapes, such as other polygonal shapes (e.g., rectangular shapes), circular shapes, and / or other shapes. Figures 55A-55D Each of them can be along Fig.56 A cross-sectional side view taken along line 5605 is shown in FIG.

[0271] Thus, a thermal radiometer is provided according to various embodiments. Using various embodiments, a thermal radiometer with various characteristics can be appropriately formed depending on the application. Various example features are provided as follows. The pixel (e.g., the thermal radiometer and associated legs) has appropriate materials and structures to provide a flat thermal radiometer (e.g., a flat bridge). A flatter thermal radiometer is better able to avoid offsets due to material stress (e.g., relative to an initial plane), avoid stray light, and the like. A merit graph of a thermal radiometer can be based on a noise equivalent temperature difference and a thermal time constant. In one aspect, the merit value is desired to be low. In order to achieve a low merit value, it is desired to have a thin bridge and a low thermal time constant. In some cases, the quality factor is proportional to the thermal mass of the bridge and is independent of the thermal conduction of the legs.

[0272] It should be noted that the above content describes a microbolometer with an absorption layer. One or more absorption layers can be arranged above the resistive layer, and / or one or more absorption layers can be arranged below the resistive layer. The absorption layer can be in contact with the resistive layer, or one or more dielectric layers can be interposed between the absorption layer and the resistive layer. In some cases, a reinforcement layer can be in contact with the absorption layer. The reinforcement layer and the absorption layer can provide enhanced infrared absorption for the microbolometer. By way of non-limiting example, the reinforcement layer can be made of titanium, titanium oxide, Ti and TiO x A combination of, aluminum, titanium nitride, nickel, iron, zinc, platinum, tantalum, chromium, other transition metals, other metals, alloys of these metals, oxides of these materials and / or combinations of these metals and their oxides. An embodiment of a microbolometer with an absorption layer and / or an enhancement layer can be found in U.S. Pat. No. 9,945,729, the entire contents of which are incorporated herein by reference.

[0273] It should be noted that the dimensional aspects provided above are embodiments, and other values ​​of dimensions may be utilized according to one or more embodiments. In addition, the dimensional aspects provided above are generally nominal values. As will be appreciated by those skilled in the art, each dimensional aspect has a tolerance associated with that dimensional aspect. Similarly, the aspects provided above related to the distance between components are also embodiments and have associated tolerances. It should also be noted that although the above content describes the use of an etching operation to form a perforation, as will be appreciated by those skilled in the art, other semiconductor processing techniques suitable for removing material (e.g., a drilling operation, a laser operation) may also be performed to form the perforation.

[0274] Where applicable, various embodiments of the present invention may be implemented using hardware, software, or various combinations of hardware and software. Where applicable, the various hardware components and / or software components described herein may be combined into composite components consisting of software, hardware, and / or both, without departing from the scope and functionality of the present invention. Where applicable, the various hardware components and / or software components described herein may be separated into subcomponents having software, hardware, and / or both, without departing from the scope and functionality of the present invention. Where applicable, it may be considered that a software component may be implemented as a hardware component, and vice versa.

[0275] Software according to the present invention (such as program code and / or data) can be stored on one or more computer-readable media. It is also contemplated that the software identified herein can be implemented using one or more general or special-purpose computers and / or computer systems, networking and / or other means. Where applicable, the order of the various steps described herein can be changed, combined into composite steps, and / or separated into sub-steps to provide the functions described herein.

[0276] Although the present invention has been described in detail with respect to only limited embodiments, it should be readily understood that the present invention is not limited to these disclosed embodiments. Rather, the present invention may be modified to incorporate any number of variations, changes, alternatives, or equivalent arrangements not described, but which are consistent with the spirit and scope of the present invention. Furthermore, although various embodiments of the present invention have been described, it should be understood that various aspects of the present invention may include only some of the described embodiments. Therefore, the present invention should not be considered to be limited by the foregoing description, but only by the scope of the appended claims.

Claims

1. An infrared imaging device, comprising: a substrate comprising a plurality of contacts and a surface, wherein the surface defines a plane; A microbolometer array, the microbolometer array comprising a plurality of microbolometers, wherein each microbolometer comprises: A microbolometer bridge, the microbolometer bridge comprising: a first portion comprising a resistive layer configured to capture infrared radiation; and a second portion having a plurality of perforations defined therein; and A leg structure coupled to the microbolometer bridge and one of the plurality of contacts, wherein the leg structure comprises a cross-section having a first section, a second section, and a third section, the second section being substantially parallel to the first section, the third section connecting the first section and the second section, wherein the leg structure comprises: a first segment, the first segment being associated with the first section and having a first dimension extending in a first direction substantially parallel to the plane and a second dimension extending in a second direction substantially perpendicular to the plane, wherein the first dimension is greater than the second dimension; a second segment, the second segment being associated with the second section; and a third segment, the third segment being associated with the third region and adjacent to the first segment and the second segment, the third segment having a third dimension extending in the first direction and a fourth dimension extending in the second direction, wherein the third dimension is smaller than the fourth dimension, wherein: Each of the first segment, the second segment, and the third segment includes a corresponding portion of the first metal layer, a corresponding portion of the first layer, and a corresponding portion of the second layer, The first layer is formed on a first sidewall of the first metal layer and a first side of the first metal layer, The second layer is formed on the second sidewall of the first metal layer and the second side of the first metal layer, The first side wall is opposite to the second side wall, and The first side is opposite to the second side.

2. The infrared imaging device according to claim 1, wherein: The first portion further includes a first insulator and a second insulator, wherein the resistive layer is disposed on the first insulator, and wherein the second insulator is disposed on the resistive layer.

3. The infrared imaging device according to claim 2, wherein: The first portion also includes an absorber layer disposed on the second insulator.

4. The infrared imaging device according to claim 3, wherein: The first portion also includes a third insulator disposed on the absorber layer.

5. The infrared imaging device according to claim 2, wherein: The first portion further comprises an absorber layer, and wherein the first insulator is disposed on the absorber layer.

6. The infrared imaging device according to claim 1, wherein: The resistance layer has no portion in the second portion.

7. The infrared imaging device according to claim 1, wherein: The third section is substantially perpendicular to the first section and the second section.

8. The infrared imaging device according to claim 1, wherein: The third section is at an angle relative to the first section and the second section.

9. The infrared imaging device according to claim 1, wherein: The leg structure extends between the microbolometer bridge and the one of the plurality of contacts in a first direction substantially parallel to the plane.

10. The infrared imaging device according to claim 9, wherein: The cross section is an S-shaped cross section or a Z-shaped cross section maintained along the first direction, The first section and the second section extend along the first direction and a third direction substantially parallel to the plane, and The third section connects the first section and the second section in a second direction.

11. The infrared imaging device according to claim 1, wherein: A portion of the first layer and a portion of the second layer are separated by a gap, and wherein the portion of the first layer faces the portion of the second layer.

12. The infrared imaging device according to claim 1, wherein: The first part also includes: a cap layer facing the substrate; a second metal layer disposed on the cap layer; a first dielectric layer disposed between the second metal layer and the resistive layer; a second dielectric layer disposed on the resistive layer; and a third dielectric layer disposed on the second dielectric layer, Wherein, the leg structure is in contact with the third dielectric layer.

13. The infrared imaging device according to claim 12, wherein: The first part also includes: a third metal layer disposed on the third dielectric layer; and A fourth dielectric layer is disposed on the third metal layer.

14. The infrared imaging device according to claim 1, wherein: The first part also includes: a cap layer facing the substrate; a first dielectric layer disposed on the cap layer; a second dielectric layer, wherein the resistive layer is disposed between the first dielectric layer and the second dielectric layer; a second metal layer disposed on the second dielectric layer, and a third dielectric layer disposed on the second metal layer, Wherein, the leg structure is in contact with the third dielectric layer.

15. The infrared imaging device according to claim 1, wherein: The microbolometer bridge, the leg structure and the through-holes are along a common plane.

16. A method of forming the infrared imaging device of claim 1, the method comprising: forming a bridge structure; forming an outrigger structure; as well as A plurality of perforations are formed in the bridge structure to obtain a microbolometer bridge.

17. The method according to claim 16, further comprising: forming a microbolometer bridge on the sacrificial layer; forming an opening in the sacrificial layer; Arranging a contact metal layer on the sidewalls of the opening; forming the leg structure coupled to the microbolometer bridge and the contact metal layer; as well as The sacrificial layer is removed to suspend the microbolometer bridge and the leg structure above the substrate of the infrared imaging device, wherein the contact metal layer is coupled to the substrate.

18. The method according to claim 17, wherein: Forming the microbolometer bridge comprises: disposing a first dielectric layer on the cap layer; disposing the resistive layer on the first dielectric layer; disposing a set of dielectric layers on the resistive layer; disposing a second metal layer on the set of dielectric layers; and A second dielectric layer is disposed on the second metal layer.

19. The method according to claim 18, wherein: The forming the microbolometer bridge further includes etching through a portion of the cap layer, a portion of the first dielectric layer, a portion of each dielectric layer of the set of dielectric layers, a portion of the second metal layer, and a portion of the second dielectric layer to define a plurality of vias.

20. The method according to claim 17, wherein: Forming the microbolometer bridge comprises: disposing a second metal layer on the cap layer; disposing a first set of dielectric layers on the second metal layer; disposing a resistive layer on the first set of dielectric layers; disposing a second set of dielectric layers on the resistive layer, and A portion of the cap layer, a portion of the second metal layer, a portion of each dielectric layer of the first set of dielectric layers, and a portion of each dielectric layer of the second set of dielectric layers are etched through to define a plurality of through holes.

21. The method according to claim 17, wherein: The leg structure includes a first a cross section of a first zone, a second zone and a third zone, the second zone being substantially parallel to the first zone, The third section connects the first section and the second section.

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