Photosensitive imaging devices and associated methods

• US 8,692,198 B2
• Filed: 04/21/2011
• Issued: 04/08/2014
• Est. Priority Date: 04/21/2010
• Status: Active Grant

• Current Assignee: SiOnyx, LLC (DC Capital Partners, LLC)
• Original Assignee: SiOnyx, LLC (DC Capital Partners, LLC)
• Inventors: Jiang, Jutao, McKee, Jeffrey, Pralle, Martin U.
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): Jo, Taeho
• Application Number:
  US13/091,969
• Publication Number:
  US 20110260059A1
• Time in Patent Office: 1,083 Days
• Field of Search: 250/330, 250/200, 250/300
• US Class Current: 250/330
• 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. An imager device, comprising:

a plurality of rows of photodiodes for detecting impinging electromagnetic radiation and accumulating an electrical charge;

a global transfer gate transistor coupled to the photodiodes for gating the photodiodes, wherein an open state of the global transfer gate transistor causes the electrical charge from the photodiodes to accumulate at an accumulation node;

a transfer gate transistor coupled to the accumulation node for gating the accumulation node, wherein an open state of the transfer gate transistor causes the electrical charge from the accumulation node to accumulate as a signal at a floating diffusion node;

a source follower transistor coupled to the floating diffusion node and configured to receive the signal from the floating diffusion node, wherein the source follower transistor amplifies the signal;

a row select gate transistor coupled to the source follower transistor, wherein the row select gate transistor reads out the signal from successive of the plurality of rows of photodiodes;

a reset gate transistor coupled between a voltage source and the floating diffusion node, wherein an open state of the reset gate transistor resets the electrical charge at the floating diffusion node;

a global reset transistor coupled between the photodiodes and the voltage source, wherein an open state of the global reset transistor prevents accumulation of the electrical charge at the photodiodes; and

a clock coupled to the global reset transistor and synchronized with pulses of a pulsed light source to create the global reset transistor open state between the pulses.

2. The device of claim 1, wherein at least one photodiode of the plurality of rows of photodiodes further includes:

a semiconductor material having a doped region forming a junction and a light diffusion region coupled to the semiconductor material, the light diffusion region being positioned to interact with electromagnetic radiation.

3. The device of claim 2, wherein the light diffusing region is a textured region.