Uneven-trench pixel cell and fabrication method
Granted: April 2, 2024
Patent Number:
11948965
An uneven-trench pixel cell includes a semiconductor substrate that includes a floating diffusion region, a photodiode region, and, between a front surface and a back surface: a first sidewall surface, a shallow bottom surface, a second sidewall surface, and a deep bottom surface. The first sidewall surface and a shallow bottom surface define a shallow trench, located between the floating diffusion region and the photodiode region, that extends into the semiconductor substrate from the…
Electronic camera module with integral LED and light-pipe illuminator
Granted: March 26, 2024
Patent Number:
11943525
An electronic camera assembly includes a camera chip cube bonded to camera bondpads of an interposer; at least one light-emitting diode (LED) bonded to LED bondpads of the interposer at the same height as the camera bondpads; and a housing extending from the interposer and LEDs to the height of the camera chip cube, with light guides extending from the LEDs through the housing to a top of the housing. In embodiments, the electronic camera assembly includes a cable coupled to the…
Stack chip air gap heat insulator
Granted: March 26, 2024
Patent Number:
11942504
Image sensors include a pixel die that is stacked on a logic die. The logic die includes at least one function logic element disposed on a bond side thereof, and a logic oxide array of raised logic oxide features also disposed on the bond side. The pixel die includes a pixel array disposed on a light receiving side thereof, and a pixel oxide array of raised pixel oxide features disposed on a bond side of the pixel die. A plurality of outer bonds is disposed between an outer region of the…
Transistor having increased effective channel width
Granted: February 13, 2024
Patent Number:
11901383
Methods of forming transistors include providing a substrate material, forming a recess to a first depth in the substrate material, the recess corresponding to a gate region and extending in a channel length direction and a channel width direction that is perpendicular to the channel length direction, forming a trench structure in the substrate material by deepening the recess to a second depth using an isotropic process, forming an isolation layer on the substrate material, forming a…
Transistor having increased effective channel width
Granted: February 13, 2024
Patent Number:
11901383
Methods of forming transistors include providing a substrate material, forming a recess to a first depth in the substrate material, the recess corresponding to a gate region and extending in a channel length direction and a channel width direction that is perpendicular to the channel length direction, forming a trench structure in the substrate material by deepening the recess to a second depth using an isotropic process, forming an isolation layer on the substrate material, forming a…
Passive speckle-suppressing diffusers and associated methods and illuminators
Granted: February 6, 2024
Patent Number:
11892654
A passive speckle-suppressing diffuser includes a microlens array for diffusing a light field originating from one or more coherent light beams, and a diffractive optical element mounted in series with the microlens array and having a pixelated thickness distribution, characterized by a spatial variation across the diffractive optical element, to impose a spatially varying phase shift on the light field. The pixelated thickness distribution may be configured such that the spatially…
SiGe photodiode for crosstalk reduction
Granted: January 16, 2024
Patent Number:
11876110
SiGe photodiode for crosstalk reduction. In one embodiment, an image sensor includes a plurality of pixels arranged in rows and columns of a pixel array disposed in a semiconductor material. Each pixel includes a plurality of photodiodes. The plurality of pixels are configured to receive an incoming light through an illuminated surface of the semiconductor material. Each pixel includes a first photodiode comprising a silicon (Si) material; and a second photodiode having the Si material…
Signal-charge estimator and method
Granted: January 9, 2024
Patent Number:
11871129
A method for estimating a signal charge collected by a pixel of an image sensor includes determining an average bias that depends on the pixel's floating-diffusion dark current and pixel-sampling period. The method also includes determining a signal-charge estimate as the average bias subtracted from a difference between a weighted sum of a plurality of N multiple-sampling values each multiplied by a respective one of a plurality of N sample-weights.
Circuit and method for image artifact reduction in high-density, high-pixel-count, image sensor with phase detection autofocus
Granted: January 9, 2024
Patent Number:
11871135
In an embodiment, a method of reducing resistance-capacitance delay along photodiode transfer lines of an image sensor includes forking a plurality of photodiode transfer lines each into a plurality of sublines coupled together and to a first decoder-driver at a first end of each subline; and distributing selection transistors of a plurality of multiple-photodiode cells among the plurality of sublines. In embodiments, the sublines may be recombined at a second end of the sublines and…
Devices and methods for obtaining three-dimensional shape information using polarization and time-of-flight detection pixel cells
Granted: January 9, 2024
Patent Number:
11871132
In some embodiments, an imaging system is provided. The imaging system comprises an image sensor, a light source, control circuitry, and function logic. The image sensor comprises a pixel array that includes a plurality of polarization pixel cells and a plurality of time-of-flight pixel cells. The light source is configured to emit light pulses to an object. The control circuitry is coupled to the light source and the pixel array, and is configured to synchronize a timing of the emission…
Image sensor with elevated floating diffusion
Granted: January 9, 2024
Patent Number:
11869906
A pixel cell with an elevated floating diffusion region is formed to reduce diffusion leakage (e.g., gate induced drain leakage, junction leakage, etc.). The floating diffusion region can be elevated by separating a doped floating diffusion region from the semiconductor substrate by disposing an intervening layer (e.g., undoped, lightly doped, etc.) on the semiconductor substrate and beneath the doped floating diffusion region. For instance, the elevated floating diffusion region can be…
Thin, multi-lens, optical fingerprint sensor adapted to image through cell phone displays
Granted: January 9, 2024
Patent Number:
11869267
A multiple-lens optical fingerprint reader for reading fingerprints through a display has a spacer; and multiple microlenses with concave and convex surfaces in a microlens array, each microlens of multiple lenses focuses light arriving at that microlens from a finger adjacent the display through the spacer forms an image on associated photosensors on a photosensor array of an image sensor integrated circuit. A method of verifying identity of a user includes illuminating a finger of the…
Electrical isolation in pixel-array substrates using combination of doped semiconductor guard rings and overlapping isolation trenches
Granted: January 2, 2024
Patent Number:
11862678
A pixel-array substrate includes a semiconductor substrate with a pixel array, a back surface, and a front surface, and a guard ring formed of a doped semiconductor, enclosing the pixel array, and extending into the semiconductor substrate from the front surface, the back surface forming a trench extending into the semiconductor substrate, the trench overlapping the guard ring. A method for reducing leakage current into a pixel-array includes doping a semiconductor substrate to form a…
Light-trapping image sensors
Granted: January 2, 2024
Patent Number:
11862651
A light-trapping image sensor includes a pixel array and a lens array. The pixel array is formed in and on a semiconductor substrate and including photosensitive pixels each including a reflective material forming a cavity around a portion of semiconductor material to at least partly trap light that has entered the cavity. The cavity has a ceiling at a light-receiving surface of the semiconductor substrate, and the ceiling forms an aperture for receiving the light into the cavity. The…
Shallow trench isolation (STI) structure for CMOS image sensor
Granted: January 2, 2024
Patent Number:
11862509
A shallow trench isolation (STI) structure and method of fabrication includes forming a shallow trench isolation (STI) structure having a polygonal shaped cross-section in a semiconductor substrate of an image sensor includes a two-step etching process. The first step is a dry plasma etch that forms a portion of the trench to a first depth. The second step is a wet etch process that completes the trench etching to the desired depth and cures damage caused by the dry etch process. A CMOS…
Flare-suppressing image sensor
Granted: January 2, 2024
Patent Number:
11860383
Embodiments disclosed herein reduce petal flare. A flare-suppressing image sensor includes a plurality of pixels including a first set of pixels and a second set of pixels. The flare-suppressing image sensor further includes plurality of microlenses, where each microlens is aligned to a respective one of the first set of pixels. The flare-suppressing image sensor further includes plurality of sub-microlens, where each microlens array is aligned to a respective one of the second set of…
HV driver for rolling clamp in image sensor
Granted: December 12, 2023
Patent Number:
11843884
An imaging system includes a pixel array with pixel circuits, each including a photodiode, a floating diffusion, a source follower transistor, and a row select transistor. The imaging system further includes rolling clamp (RC) drivers, each coupled to a gate terminal of a row select transistor of one of the pixel circuits and each including first and second PMOS transistors coupled between a clamp voltage and the gate terminal of the row select transistor of the one of the pixel…
Optical fingerprint sensor with spoof detection and associated method
Granted: December 12, 2023
Patent Number:
11842563
An optical fingerprint sensor with spoof detection includes a plurality of lenses, an image sensor including a pixel array that includes a plurality of first photodiodes and a plurality of second photodiodes, and at least one apertured baffle-layer having a plurality of aperture stops, wherein each second photodiode is configured to detect light having passed through a lens and at least one aperture stop not aligned with the lens along an optical axis. A method for detecting spoof…
CMOS image sensor pixel for high dynamic range capturing
Granted: November 28, 2023
Patent Number:
11830894
An image sensor element includes a transfer transistor TX, a LOFIC select transistor LF, a photodiode PD, and a first overflow path OFP. The transfer transistor TX outputs a readout signal from a first end. The LOFIC select transistor LF includes a first end connected to a second end of the transfer transistor TX, and a second end connected to a capacitor. The photodiode PD is connected in common to a third end of the transfer transistor and a third end of the LOFIC select transistor LF.…
Pixel-array substrate
Granted: November 7, 2023
Patent Number:
11810931
A pixel-array substrate includes (i) a semiconductor substrate including a photodiode region and a floating diffusion region, and (ii) a vertical-transfer-gate structure that includes a trench and a gate electrode. The trench is defined by a bottom surface and a sidewall surface of the substrate each located between a front substrate-surface and a back substrate-surface thereof. The trench extends into the substrate. In a cross-sectional plane perpendicular to the front substrate-surface…
