Infrared solid-state imaging sensing device

• US 6,465,784 B1
• Filed: 06/19/2000
• Issued: 10/15/2002
• Est. Priority Date: 12/18/1997
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Kimata, Masafumi
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): GAGLIARDI, ALBERT J
• Application Number:
  US09/581,808
• Time in Patent Office: 848 Days
• Field of Search: 250/332, 250/338.1, 250/338.4, 250/339.02, 250/349, 250/370.08, 250/370.14, 252/431, 252/436, 252/467, 252/470, 438/54, 438/57
• US Class Current: 250/332
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: G01J 5/34 using capacitors, e.g. pyroelectric capacitors

Abstract

Infrared solid-state imaging elements include an infrared absorbing section formed as to correspond to each pixel aligned in a two-dimensional pattern for absorbing incident infrared radiation and converting the same into heat. A temperature detector section is formed as to correspond to each pixel on a semiconductor substrate and are arranged of a plurality of serially connected silicon pn junction diodes that are biased in a forward direction. A hollow section is formed on each region on which the temperature detector section is formed on the semiconductor substrate. Supporting mechanisms are arranged of materials exhibiting large thermal resistance and which support the temperature detector portion above the hollow section on the semiconductor substrate. A joint column thermally couples the infrared absorbing section and the temperature detector section.

Claims

1. An infrared solid-state imaging element formed corresponding to each pixel of a two-dimensional imaging array comprising:

an infrared absorbing section formed corresponding to each pixel of an two-dimensional imaging array and converting incident infrared radiation into heat;

a temperature detector section formed corresponding to each pixel on a semi-conductor substrate having a plurality of pn junction diodes connected in series and biased in forward direction;

a hollow section formed under each temperature detector section;

a supporting leg having a large thermal resistance and supporting each temperature detector section on each hollow section;

a joint column holding the infrared absorbing section on the temperature detector section in a separate manner and thermally connecting the infrared absorbing section and the temperature detector section.

2. The infrared solid-state imaging element of claim 1, wherein a SOI (silicon on insulator) substrate is used as the semiconductor substrate.

3. The infrared solid-state imaging element of claim 1, wherein the pn junction diodes of the temperature detector section are formed in a single crystal silicon layer in a form of a plurality of p-type layers and n-type layers arranged alternatively and each connection between the p-type layer and n-type layer biased in reverse direction when applied with a voltage is connected with metal wiring.

4. The infrared solid-state imaging element of claim 3, wherein the metal wirings connecting the pn junction diodes are formed of platinum siliside.

5. The infrared solid-state imaging element of claim 1, wherein the pn junction diodes of the temperature detector section are formed in n-type region embeded in p-type semiconductor substrate.

6. The infrared solid-state imaging element of claim 1, wherein the infrared absorbing section is comprised of a infrared absorbing metal thin film, an insulating film, and a reflecting metal film.

7. The infrared solid-state imaging element of claim 1, wherein the infrared absorbing section is comprised of an insulating film and a reflecting metal film.

8. The infrared solid-state imaging element of claim 1, wherein the joint column is formed from the same material as the material used to form the infrared absorbing section.

9. The infrared solid-state imaging element of claim 1, wherein the hollow section is provided with an etching stoper layer around its periphery.

10. The infrared solid-state imaging element of claim 1, wherein a constant current source having one end connected to a fixed potential is provided for each vertical line of the two-dimensional pixel array.

11. The infrared solid-state imaging element of claim 1, wherein a resistor having one end connected to a fixed potential is provided for each vertical line of the two-dimensional pixel array.

12. The infrared solid-state imaging element of claim 1, wherein diodes having one end connected to a fixed potential are provided for each vertical line of the two-dimensional pixel array.

13. The infrared solid-state imaging element of claim 12, wherein the diodes comprise a plurality of identical diodes to the diodes used in the temperature detector section in number and shape.

14. The infrared solid-state imaging element of claim 1, wherein each vertical line of the two-dimensional pixel array is connected to a common load through a respective horizontal scanning transistor.

15. The infrared solid-state imaging element of claim 14, wherein the common load comprises a plurality of identical diodes to the diodes used in the temperature detecting section in number and shape.