Photosensitive imaging devices and associated methods

• US 9,911,781 B2
• Filed: 03/24/2014
• Issued: 03/06/2018
• Est. Priority Date: 09/17/2009
• Status: Active Grant

• Current Assignee: SiOnyx, LLC (DC Capital Partners, LLC)
• Original Assignee: SiOnyx, LLC (DC Capital Partners, LLC)
• Inventors: Haddad, Homayoon, Jiang, Jutao, McKee, Jeffrey, Miller, Drake, Forbes, Leonard, Palsule, Chintamani
• Primary Examiner(s): BACHNER, ROBERT G
• Application Number:
  US14/223,938
• Publication Number:
  US 20150270306A1
• Time in Patent Office: 1,443 Days
• Field of Search: None
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H01L 27/1462 Coatings
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14629 Reflectors
• CPC Class Codes: H01L 27/1463 Pixel isolation structures
• CPC Class Codes: H01L 27/14638 Structures specially adapted for transferring the charges across the imager perpendicular to the imaging plane
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/14685 Process for coatings or optical elements
• CPC Class Codes: H01L 27/14689 MOS based technologies
• CPC Class Codes: H01L 27/14698 Post-treatment for the devices, e.g. annealing, impurity-gettering, shor-circuit elimination, recrystallisation

Abstract

Photosensitive devices and associated methods are provided. In one aspect, for example, a photosensitive imager device can include a semiconductor substrate having multiple doped regions forming at least one junction, a textured region coupled to the semiconductor substrate and positioned to interact with electromagnetic radiation, and an electrical transfer element coupled to the semiconductor substrate and operable to transfer an electrical signal from the at least one junction. In one aspect, the textured region is operable to facilitate generation of an electrical signal from the detection of infrared electromagnetic radiation. In another aspect, interacting with electromagnetic radiation further includes increasing the semiconductor substrate'"'"'s effective absorption wavelength as compared to a semiconductor substrate lacking a textured region.

Claims

1. A photosensitive imager device, comprising:

a semiconductor substrate having a light-incident surface, a back surface opposed to said light-incident surface and at least one side surface, said semiconductor substrate having multiple doped regions forming at least one junction, said side surface having at least a textured region coupled to the semiconductor substrate and positioned to interact with electromagnetic radiation to provide reflection of radiation so as to increase effective absorption of radiation in the semiconductor substrate;

wherein said textured region comprises surface features with sizes in a range of about 50 nm to about 2 microns, and

an electrical transfer element coupled to the semiconductor substrate and operable to transfer an electrical signal from the at least one junction.

2. The device of claim 1, wherein the textured region is operable to facilitate generation of an electrical signal from the detection of infrared electromagnetic radiation.

3. The device of claim 1, wherein the transfer element is selected from the group consisting of a transistor, a sensing node, a transfer gate, and combinations thereof.

4. The device of claim 1, further comprising a reflective layer coupled to the semiconductor substrate and positioned to maintain the electromagnetic radiation in the semiconductor substrate.

5. The device of claim 1, wherein the textured region has been formed by a process selected from the group consisting of lasing, chemical etching, nanoimprinting, material deposition, and combinations thereof.

6. The device of claim 1, further comprising a lens optically coupled to the semiconductor substrate and positioned to focus incident electromagnetic radiation into the semiconductor substrate.

7. A photosensitive image array, comprising at least two photosensitive imager devices of claim 1.

8. The photosensitive image array of claim 7, further comprising at least one trench isolation positioned between the at least two photosensitive imager device.

10. The photosensitive imager device of claim 1, wherein said semiconductor substrate includes multiple side surfaces each of which has a textured region.

9. A photosensitive imager device, comprising:

a semiconductor substrate having a light-incident surface, a back surface opposed to said light-incident surface and at least one side surface, said semiconductor substrate further having multiple doped regions forming at least one junction, said side surface having at least a textured region coupled to the semiconductor substrate and positioned to interact with electromagnetic radiation to provide reflection of radiation so as to increase effective absorption of radiation in the semiconductor substrate, wherein said textured region comprises surface features with sizes in a range of about 50 nm to about 2 microns; and

at least 4 transistors coupled to the semiconductor substrate and with at least one of the transistors electrically coupled to the at least one junction.

11. A photosensitive imager device, comprising:

a semiconductor substrate having a light-incident surface, a back surface opposed to said light-incident surface and at least one side surface, said semiconductor substrate having multiple doped regions forming at least one junction, said side surface having at least a textured region coupled to the semiconductor substrate and positioned to interact with electromagnetic radiation;

wherein said textured region comprises surface features with sizes in a range of about 50 nm to about 2 microns, and

an electrical transfer element coupled to the semiconductor substrate and operable to transfer an electrical signal from the at least one junction,

wherein the transfer element is selected from the group consisting of a transistor, a sensing node, a transfer gate, and combinations thereof.

12. The device of claim 11, wherein the textured region is operable to facilitate generation of an electrical signal from the detection of infrared electromagnetic radiation.

13. The device of claim 11, further comprising a reflective layer coupled to the semiconductor and positioned to maintain the electromagnetic radiation in the semiconductor substrate.

14. The device of claim 11, wherein said surface features are selected from the group consisting of cones, pillars, pyramids, microlenses, quantum dots, inverted features, and combinations thereof.