LIGHT GUIDE ARRAY FOR AN IMAGE SENSOR

• US 20110031381A1
• Filed: 07/02/2009
• Published: 02/10/2011
• Est. Priority Date: 12/28/2007
• Status: Abandoned Application

• Current Assignee: Hiok-Nam Tay, Thanh-Trung Do
• Original Assignee: Hiok-Nam Tay, Thanh-Trung Do
• Inventors: TAY, HIOK-NAM, DO, THANH-TRUNG
• Application Number:
  US12/806,192
• Publication Number:
  US 20110031381A1
• Time in Patent Office: Days
• US Class Current: 250/226
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14623 Optical shielding
• 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 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/14685 Process for coatings or optical elements
• CPC Class Codes: H01L 27/14687 Wafer level processing

Abstract

An image sensor pixel that includes a photoelectric conversion unit supported by a substrate and an insulator adjacent to the substrate. The pixel includes a cascaded light guide that is located within an opening of the insulator and extends above the insulator such that a portion of the cascaded light guide has an air interface. The air interface improves the internal reflection of the cascaded light guide. The cascaded light guide may include a self-aligned color filter having air-gaps between adjacent color filters. Air-gaps may be sealed from above by a transparent sealing film. The transparent sealing film may have a concave surface over the air-gap to diverge light that cross the concave surface into the air-gap away from the air-gap into adjacent color filters. These characteristics of the light guide eliminate the need for a microlens. Additionally, a portion of a support wall between a pair of color filters may have a larger width above than below to form a necking to hold down the color filters for better retention.

Claims

8. The image sensor of claim 4, wherein each of said light guides is directly under a corresponding one of said color filters.

9. The image sensor of claim 4, wherein no microlens is disposed on an opposite side of each of said color filters away from a corresponding one of said photoelectric conversion units.