Infrared sensor

• US 7,282,712 B2
• Filed: 05/21/2003
• Issued: 10/16/2007
• Est. Priority Date: 04/10/2001
• Status: Expired due to Fees

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hamamatsu Photonics KK
• Inventors: Shibayama, Katsumi
• Primary Examiner(s): GAWORECKI, MARK R
• Application Number:
  US10/442,109
• Publication Number:
  US 20030205670A1
• Time in Patent Office: 1,609 Days
• Field of Search: 250/338.4, 136/225
• US Class Current: 250/338.4
• CPC Class Codes: G01J 5/10 using electric radiation detectors
• CPC Class Codes: G01J 5/12 using thermoelectric elements, e.g. thermocouples

Abstract

An infrared sensor of this invention is characterized by including a support member including a support film and a substrate that supports the support film, a polysilicon film which ranges from above a concavity to above the substrate, SiO₂ which is formed on the polysilicon film and has a first junction hole above the concavity and a second junction hole above the substrate, an aluminum film which is connected to the polysilicon film through the first junction hole and connected to an adjacent polysilicon film through the second junction hole, and a heat absorption layer formed above the concavity to cover a portion above the first junction hole, wherein the aluminum film is stacked on the corresponding polysilicon film via the SiO₂ above the concavity.

Claims

1. An infrared sensor comprising:

a support member including a support film made of an insulating material and a substrate that has a concavity and supports the support film;

a plurality of polysilicon layers each of which has a predetermined conductivity type and extends from a location above the concavity to a location above the substrate, and each of which comprises an elongated portion having edges that extend parallel to one another in a longitudinal direction of the elongated portion, and a tapered portion located at a distal end of the elongated portion located above the concavity and being configured such that edges of the tapered portion gradually converge toward one another in a non-parallel fashion in a distal direction of the elongated portion;

an insulating film which is formed on the polysilicon layers and has a first junction hole formed above the concavity and a second junction hole formed above the substrate;

an aluminum wiring layer which is connected to a first one of the polysilicon layers through the first junction hole and which is connected to an adjacent one of the polysilicon layers through the second junction hole; and

an infrared absorption layer formed above the concavity to cover a portion above the first junction hole,

wherein the aluminum layer connected to the first polysilicon layer through the first junction hole is stacked via the insulating film as an overlying layer of the first polysilicon layer above the concavity, and

wherein the tapered portion of the first polysilicon wiring layer is coupled to the elongated portion of the first polysilicon wiring layer, and a hot junction portion is formed within the elongated portion of the first polysilicon wiring layer at a location where the aluminum wiring layer is connected to the first polysilicon wiring layer through the first junction hole.

2. An infrared sensor according to claim 1, characterized in that the substrate is made of silicon, and the concavity is formed by etching.

3. An infrared sensor according to claim 2, characterized in that the aluminum layer is formed to be narrower than the first polysilicon layer at least above the concavity.

4. An infrared sensor according to claim 2, characterized in that a plurality of multilayered structures each of which has the aluminum layer stacked on the first polysilicon layer via the insulating film are formed, and the plurality of first junction holes are covered with the infrared absorption layer integrally formed.

5. An infrared sensor according to claim 1, characterized in that the aluminum layer is formed to be narrower than the first polysilicon layer at least above the concavity.

6. An infrared sensor according to claim 5, characterized in that a plurality of multilayered structures each of which has the aluminum layer stacked on the first polysilicon layer via the insulating film are formed, and the plurality of first junction holes are covered with said infrared absorption layer integrally formed.

7. An infrared sensor according to claim 1, characterized in that a plurality of multilayered structures each of which has the aluminum layer stacked on the first polysilicon layer via the insulating film are formed, and the plurality of first junction holes are covered with the infrared absorption layer integrally formed.

8. An infrared sensor according to claim 1, wherein said infrared absorption layer is made of blackened resin material.