Microbolometer systems and methods
Microbolometer systems and methods are provided herein. For example, an infrared imaging device includes a substrate having contacts and a surface. The surface defines a plane. The infrared imaging device further includes a microbolometer array coupled to the substrate. Each microbolometer of the microbolometer array includes a second having a first dimension that extends in a first direction substantially parallel to the plane and a second dimension that extends in a second direction away from the plane. The first dimension is less than the second dimension. The segment includes a metal layer and a layer formed on a side of the metal layer.
1 . An infrared imaging device comprising:
a substrate comprising a plurality of contacts and a surface, wherein the surface defines a plane; and
a microbolometer array coupled to the substrate, wherein the microbolometer array comprises a plurality of microbolometers, and wherein each microbolometer comprises:
a bridge; and
a leg structure coupled to the bridge and to one of the plurality of contacts, wherein the leg structure comprises a first segment having a first dimension that extends in a first direction substantially parallel to the plane and a second dimension that extends in a second direction away from the plane, wherein the first dimension is less than the second dimension, wherein the first segment comprises at least a portion of a first metal layer and at least a portion of a first layer formed on a first side of the first metal layer, wherein a cross-section of the leg structure has a first section, a second section substantially parallel to the first section, and a third section joining the first section and the second section, and wherein the first segment is associated with the third section.
2 . The infrared imaging device of claim 1 , wherein the cross-section of the leg structure comprises a stack in a direction along the plane formed of the portion of the first layer and the portion of the first metal layer and maintained as the leg structure extends along a substantial length of the leg structure to form the stack when viewed in a direction along the length of the leg structure.
3 . The infrared imaging device of claim 1 , wherein the first segment further comprises at least a portion of a second layer formed on a second side of the first metal layer opposite the first side of the first metal layer, and wherein the portion of the first layer, the portion of the first metal layer, and the portion of the second layer are adjacent to each other and stacked in a direction along the plane.
4 . The infrared imaging device of claim 3 , wherein the first layer is a dielectric layer, wherein the second layer is a semiconductor layer or a dielectric layer, and wherein the cross-section of the leg structure comprises a stack in the direction along the plane formed of the portion of the first layer, the portion of the first metal layer, and the portion of the second layer and maintained as the leg structure extends along a substantial length of the leg structure to form the stack when viewed in a direction along the length of the leg structure.
5 . The infrared imaging device of claim 1 , wherein:
the portion of the first metal layer comprises a first portion of the first metal layer;
the portion of the first layer comprises a first portion of the first layer;
the second direction is substantially perpendicular to the plane; and
the leg structure further comprises a second segment adjacent to the first segment, wherein the second segment comprises:
a second portion of the first metal layer adjacent to the first portion of the first metal layer; and
a second portion of the first layer adjacent to the first portion of the first layer.
6 . The infrared imaging device of claim 1 , further comprising:
a contact metal layer coupled to the substrate and the leg structure;
an overglass layer disposed on the substrate; and
a pad disposed on the overglass layer and coupled to the one of the plurality of contacts, wherein the contact metal layer is in contact with the pad.
7 . A method of forming the infrared imaging device of claim 1 , the method comprising:
forming the bridge on a sacrificial layer;
forming an opening in the sacrificial layer;
disposing a contact metal layer on sidewalls of the opening;
forming the leg structure that couples to the bridge and the contact metal layer, and
removing the sacrificial layer to suspend the bridge and the leg structure above the substrate, wherein the contact metal layer is coupled to the substrate.
8 . The method of claim 7 , wherein the cross-section of the leg structure comprises a stack in a direction along the plane formed of the portion of the first layer and the portion of the first metal layer and maintained as the leg structure extends along a substantial length of the leg structure to form the stack when viewed in a direction along the length of the leg structure.
9 . The method of claim 7 , wherein the first segment further comprises at least a portion of a second layer formed on a second side of the first metal layer opposite the first side of the first metal layer, and wherein the portion of the first layer, the portion of the first metal layer, and the portion of the second layer are adjacent to each other and stacked in a direction along the plane.
10 . The method of claim 9 , wherein the cross-section of the leg structure comprises a stack in the direction along the plane formed of the portion of the first layer, the portion of the second layer, and the portion of the first metal layer and maintained as the leg structure extends along a substantial length of the leg structure to form the stack when viewed in a direction along the length of the leg structure.
11 . The method of claim 7 , wherein:
the portion of the first metal layer comprises a first portion of the first metal layer;
the portion of the first layer comprises a first portion of the first layer;
the leg structure further comprises a second segment adjacent to the first segment, wherein the second segment comprises:
a second portion of the first metal layer adjacent to the first portion of the first metal layer; and
a second portion of the first layer adjacent to the first portion of the first layer.
12 . The method of claim 11 , wherein:
the leg structure further comprises a third segment adjacent to the first segment, wherein the third segment comprises:
a third portion of the first metal layer adjacent to the first portion of the first metal layer; and
a third portion of the first layer adjacent to the first portion of the first layer; and
the cross-section of the leg structure comprises a shape formed of the first segment, the second segment, and the third segment and maintained as the leg structure extends along a substantial length of the leg structure to form the shape when viewed in a direction along the length of the leg structure.
13 . The method of claim 7 , wherein the forming the bridge comprises:
disposing a first set of dielectric layers on a second metal layer;
disposing a resistive layer on the first set of dielectric layers; and
disposing a second set of dielectric layers on the resistive layer, wherein the leg structure is in contact with the second set of dielectric layers.
14 . The method of claim 7 , wherein the second direction is substantially perpendicular to the plane, wherein the forming the opening exposes a pad disposed on an overglass layer of the infrared imaging device, and wherein the overglass layer is disposed on the substrate.
15 . An infrared imaging device comprising:
a substrate comprising a plurality of contacts and a surface, wherein the surface defines a plane; and
a microbolometer array coupled to the substrate, wherein the microbolometer array comprises a plurality of microbolometers, and wherein each microbolometer comprises:
a bridge; and
a leg structure coupled to the bridge and to one of the plurality of contacts, wherein the leg structure comprises a first segment having a first dimension that extends in a first direction substantially parallel to the plane and a second dimension that extends in a second direction away from the plane, wherein the first dimension is less than the second dimension, and wherein the first segment comprises at least a portion of a first metal layer and at least a portion of a first layer formed on a first side of the first metal layer, wherein:
the portion of the first metal layer comprises a first portion of the first metal layer;
the portion of the first layer comprises a first portion of the first layer;
the second direction is substantially perpendicular to the plane;
the leg structure further comprises a second segment adjacent to the first segment, wherein the second segment comprises:
a second portion of the first metal layer adjacent to the first portion of the first metal layer; and
a second portion of the first layer adjacent to the first portion of the first layer; and
the leg structure further comprises a third segment adjacent to the first segment, wherein the third segment comprises:
a third portion of the first metal layer adjacent to the first portion of the first metal layer; and
a third portion of the first layer adjacent to the first portion of the first layer.
16 . The infrared imaging device of claim 15 , wherein a cross-section of the leg structure comprises a shape formed of the first segment, the second segment, and the third segment and maintained as the leg structure extends along a substantial length of the leg structure to form the shape when viewed in a direction along the length of the leg structure.
17 . The infrared imaging device of claim 15 , wherein the first segment is substantially perpendicular to the second and third segments.
18 . The infrared imaging device of claim 15 , wherein the first segment is at an angle relative to the second and third segments.
19 . An infrared imaging device comprising:
a substrate comprising a plurality of contacts and a surface, wherein the surface defines a plane; and
a microbolometer array coupled to the substrate, wherein the microbolometer array comprises a plurality of microbolometers, and wherein each microbolometer comprises:
a bridge; and
a leg structure coupled to the bridge and to one of the plurality of contacts, wherein the leg structure comprises a first segment having a first dimension that extends in a first direction substantially parallel to the plane and a second dimension that extends in a second direction away from the plane, wherein the first dimension is less than the second dimension, wherein the first segment comprises at least a portion of a first metal layer and at least a portion of a first layer formed on a first side of the first metal layer, wherein no portion of the first layer is disposed on a top surface of the first metal layer and/or no portion of the first layer is disposed on a bottom surface of the first metal layer, wherein the top surface of the first metal layer faces away from the substrate, and wherein the bottom surface of the first metal layer faces the substrate.
20 . The infrared imaging device of claim 19 , further comprising:
a contact metal layer coupled to the substrate and the leg structure;
an overglass layer disposed on the substrate; and
a pad disposed on the overglass layer and coupled to the one of the plurality of contacts, wherein the contact metal layer is in contact with the pad, and wherein a cross-section of the leg structure comprises a stack in a direction along the plane formed of the portion of the first layer and the portion of the first metal layer and maintained as the leg structure extends along a substantial length of the leg structure to form the stack when viewed in a direction along the length of the leg structure.