Photosensitive imaging devices and associated methods

• US 9,741,761 B2
• Filed: 04/04/2014
• Issued: 08/22/2017
• Est. Priority Date: 04/21/2010
• Status: Active Grant

• Current Assignee: SiOnyx, LLC (Black Silicon Holdings, Inc.)
• Original Assignee: SiOnyx, LLC (Black Silicon Holdings, Inc.)
• Inventors: Jiang, Jutao, McKee, Jeffrey, Pralle, Martin U.
• Primary Examiner(s): Makiya, David J
• Assistant Examiner(s): Jo, Taeho
• Application Number:
  US14/245,872
• Publication Number:
  US 20140332665A1
• Time in Patent Office: 1,236 Days
• Field of Search: 250330
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 27/1461 characterised by the photosensitive area
• CPC Class Codes: H01L 27/14612 involving a transistor
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/1464 Back illuminated imager structures
• CPC Class Codes: H01L 27/14645 Colour imagers
• CPC Class Codes: H01L 27/14647 Multicolour imagers having a stacked pixel-element structure, e.g. npn, npnpn or MQW elements
• CPC Class Codes: H01L 27/14649 Infrared imagers
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 25/131 including elements passing infrared wavelengths
• CPC Class Codes: H04N 25/135 based on four or more different wavelength filter elements
• CPC Class Codes: H04N 25/70 SSIS architectures; Circuits associated therewith
• CPC Class Codes: H04N 25/745 Circuitry for generating timing or clock signals
• CPC Class Codes: H04N 25/771 comprising storage means other than floating diffusion

Abstract

A monolithic sensor for detecting infrared and visible light according to an example includes a semiconductor substrate and a semiconductor layer coupled to the semiconductor substrate. The semiconductor layer includes a device surface opposite the semiconductor substrate. A visible light photodiode is formed at the device surface. An infrared photodiode is also formed at the device surface and in proximity to the visible light photodiode. A textured region is coupled to the infrared photodiode and positioned to interact with electromagnetic radiation.

Claims

1. A monolithic sensor for detecting infrared and visible light, comprising

a semiconductor substrate;

a visible light pixel configured to detect visible light, the visible light pixel being formed over the semiconductor substrate and including a first plurality of pixel transistors; and

an infrared pixel configured to detect infrared light, the infrared pixel being formed over the semiconductor substrate, in proximity to the visible light pixel, and including a second plurality of pixel transistors;

wherein the second plurality of pixel transistors includes at least one transfer transistor configured to synchronize detection of the infrared light, at the infrared pixel, with a pulse of an illuminating light, by gating an accumulation node such that;

in an open state of the transfer transistor, electrical charge generated by infrared light incident on the infrared pixel is accumulated for duration of the pulse of the illuminating light; and

in a closed state of the transfer transistor, the infrared pixel is held at reset, while visible light is detected by the visible light pixel.

2. The sensor of claim 1, further comprising a textured region coupled to the second pixel and positioned to interact with electromagnetic radiation.

3. The sensor of claim 1, wherein the second pixel has a pixel architecture that is capable of performing a global shutter operation.

4. The sensor of claim 1, wherein the visible light pixel further comprises a plurality of visible light pixels each being configured to detect a different color of visible light.

5. The sensor of claim 1, wherein the infrared pixel further comprises a pixel configured to detect infrared light having a wavelength of greater than 1000 nm.

6. The sensor of claim 1, further comprising an infrared narrow bandpass filter coupled to the infrared pixel.

7. The sensor of claim 1, further comprising image processing circuitry for combining a first output from the infrared pixel with a second output from the visible light pixel to form a composite image.

8. The sensor of claim 1, further comprising circuitry for synchronizing light capture of the infrared pixel with a pulse frequency of an infrared light source.